Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Block driver for the QCOW version 2 format |
| 3 | * |
| 4 | * Copyright (c) 2004-2006 Fabrice Bellard |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | |
Peter Maydell | 80c71a2 | 2016-01-18 18:01:42 +0000 | [diff] [blame] | 25 | #include "qemu/osdep.h" |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 26 | #include <zlib.h> |
| 27 | |
Markus Armbruster | e2c1c34 | 2022-12-21 14:35:49 +0100 | [diff] [blame] | 28 | #include "block/block-io.h" |
Alberto Garcia | c9a442e | 2018-03-06 18:14:08 +0200 | [diff] [blame] | 29 | #include "qapi/error.h" |
Michael S. Tsirkin | 0d8c41d | 2018-05-03 22:50:20 +0300 | [diff] [blame] | 30 | #include "qcow2.h" |
Paolo Bonzini | 58369e2 | 2016-03-15 17:22:36 +0100 | [diff] [blame] | 31 | #include "qemu/bswap.h" |
Peter Maydell | 5df022c | 2022-02-26 18:07:23 +0000 | [diff] [blame] | 32 | #include "qemu/memalign.h" |
Kevin Wolf | 3cce16f | 2012-03-01 18:36:21 +0100 | [diff] [blame] | 33 | #include "trace.h" |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 34 | |
Paolo Bonzini | a1b4ecf | 2022-10-13 14:36:59 +0200 | [diff] [blame] | 35 | int coroutine_fn qcow2_shrink_l1_table(BlockDriverState *bs, |
| 36 | uint64_t exact_size) |
Pavel Butsykin | 46b732c | 2017-09-18 15:42:29 +0300 | [diff] [blame] | 37 | { |
| 38 | BDRVQcow2State *s = bs->opaque; |
| 39 | int new_l1_size, i, ret; |
| 40 | |
| 41 | if (exact_size >= s->l1_size) { |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | new_l1_size = exact_size; |
| 46 | |
| 47 | #ifdef DEBUG_ALLOC2 |
| 48 | fprintf(stderr, "shrink l1_table from %d to %d\n", s->l1_size, new_l1_size); |
| 49 | #endif |
| 50 | |
Paolo Bonzini | 1736239 | 2023-06-01 13:51:45 +0200 | [diff] [blame] | 51 | BLKDBG_CO_EVENT(bs->file, BLKDBG_L1_SHRINK_WRITE_TABLE); |
Alberto Faria | 38505e2 | 2022-10-13 14:37:06 +0200 | [diff] [blame] | 52 | ret = bdrv_co_pwrite_zeroes(bs->file, |
| 53 | s->l1_table_offset + new_l1_size * L1E_SIZE, |
| 54 | (s->l1_size - new_l1_size) * L1E_SIZE, 0); |
Pavel Butsykin | 46b732c | 2017-09-18 15:42:29 +0300 | [diff] [blame] | 55 | if (ret < 0) { |
| 56 | goto fail; |
| 57 | } |
| 58 | |
Alberto Faria | 38505e2 | 2022-10-13 14:37:06 +0200 | [diff] [blame] | 59 | ret = bdrv_co_flush(bs->file->bs); |
Pavel Butsykin | 46b732c | 2017-09-18 15:42:29 +0300 | [diff] [blame] | 60 | if (ret < 0) { |
| 61 | goto fail; |
| 62 | } |
| 63 | |
Paolo Bonzini | 1736239 | 2023-06-01 13:51:45 +0200 | [diff] [blame] | 64 | BLKDBG_CO_EVENT(bs->file, BLKDBG_L1_SHRINK_FREE_L2_CLUSTERS); |
Pavel Butsykin | 46b732c | 2017-09-18 15:42:29 +0300 | [diff] [blame] | 65 | for (i = s->l1_size - 1; i > new_l1_size - 1; i--) { |
| 66 | if ((s->l1_table[i] & L1E_OFFSET_MASK) == 0) { |
| 67 | continue; |
| 68 | } |
| 69 | qcow2_free_clusters(bs, s->l1_table[i] & L1E_OFFSET_MASK, |
| 70 | s->cluster_size, QCOW2_DISCARD_ALWAYS); |
| 71 | s->l1_table[i] = 0; |
| 72 | } |
| 73 | return 0; |
| 74 | |
| 75 | fail: |
| 76 | /* |
| 77 | * If the write in the l1_table failed the image may contain a partially |
| 78 | * overwritten l1_table. In this case it would be better to clear the |
| 79 | * l1_table in memory to avoid possible image corruption. |
| 80 | */ |
| 81 | memset(s->l1_table + new_l1_size, 0, |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 82 | (s->l1_size - new_l1_size) * L1E_SIZE); |
Pavel Butsykin | 46b732c | 2017-09-18 15:42:29 +0300 | [diff] [blame] | 83 | return ret; |
| 84 | } |
| 85 | |
Kevin Wolf | 2cf7cfa | 2013-05-14 16:14:33 +0200 | [diff] [blame] | 86 | int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, |
| 87 | bool exact_size) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 88 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 89 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 2cf7cfa | 2013-05-14 16:14:33 +0200 | [diff] [blame] | 90 | int new_l1_size2, ret, i; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 91 | uint64_t *new_l1_table; |
Max Reitz | fda74f8 | 2013-09-30 17:57:21 +0200 | [diff] [blame] | 92 | int64_t old_l1_table_offset, old_l1_size; |
Kevin Wolf | 2cf7cfa | 2013-05-14 16:14:33 +0200 | [diff] [blame] | 93 | int64_t new_l1_table_offset, new_l1_size; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 94 | uint8_t data[12]; |
| 95 | |
Stefan Hajnoczi | 7289375 | 2010-10-18 16:53:53 +0100 | [diff] [blame] | 96 | if (min_size <= s->l1_size) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 97 | return 0; |
Stefan Hajnoczi | 7289375 | 2010-10-18 16:53:53 +0100 | [diff] [blame] | 98 | |
Max Reitz | b93f995 | 2014-04-29 19:03:14 +0200 | [diff] [blame] | 99 | /* Do a sanity check on min_size before trying to calculate new_l1_size |
| 100 | * (this prevents overflows during the while loop for the calculation of |
| 101 | * new_l1_size) */ |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 102 | if (min_size > INT_MAX / L1E_SIZE) { |
Max Reitz | b93f995 | 2014-04-29 19:03:14 +0200 | [diff] [blame] | 103 | return -EFBIG; |
| 104 | } |
| 105 | |
Stefan Hajnoczi | 7289375 | 2010-10-18 16:53:53 +0100 | [diff] [blame] | 106 | if (exact_size) { |
| 107 | new_l1_size = min_size; |
| 108 | } else { |
| 109 | /* Bump size up to reduce the number of times we have to grow */ |
| 110 | new_l1_size = s->l1_size; |
| 111 | if (new_l1_size == 0) { |
| 112 | new_l1_size = 1; |
| 113 | } |
| 114 | while (min_size > new_l1_size) { |
Marc-André Lureau | 21cf3e1 | 2017-06-22 13:04:16 +0200 | [diff] [blame] | 115 | new_l1_size = DIV_ROUND_UP(new_l1_size * 3, 2); |
Stefan Hajnoczi | 7289375 | 2010-10-18 16:53:53 +0100 | [diff] [blame] | 116 | } |
Stefan Weil | d191d12 | 2009-10-26 16:11:16 +0100 | [diff] [blame] | 117 | } |
Stefan Hajnoczi | 7289375 | 2010-10-18 16:53:53 +0100 | [diff] [blame] | 118 | |
Max Reitz | 84c2652 | 2016-06-15 17:36:30 +0200 | [diff] [blame] | 119 | QEMU_BUILD_BUG_ON(QCOW_MAX_L1_SIZE > INT_MAX); |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 120 | if (new_l1_size > QCOW_MAX_L1_SIZE / L1E_SIZE) { |
Kevin Wolf | 2cf7cfa | 2013-05-14 16:14:33 +0200 | [diff] [blame] | 121 | return -EFBIG; |
| 122 | } |
| 123 | |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 124 | #ifdef DEBUG_ALLOC2 |
Kevin Wolf | 2cf7cfa | 2013-05-14 16:14:33 +0200 | [diff] [blame] | 125 | fprintf(stderr, "grow l1_table from %d to %" PRId64 "\n", |
| 126 | s->l1_size, new_l1_size); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 127 | #endif |
| 128 | |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 129 | new_l1_size2 = L1E_SIZE * new_l1_size; |
Alberto Garcia | ef97d60 | 2020-01-18 20:09:26 +0100 | [diff] [blame] | 130 | new_l1_table = qemu_try_blockalign(bs->file->bs, new_l1_size2); |
Kevin Wolf | de82815 | 2014-05-20 17:12:47 +0200 | [diff] [blame] | 131 | if (new_l1_table == NULL) { |
| 132 | return -ENOMEM; |
| 133 | } |
Alberto Garcia | ef97d60 | 2020-01-18 20:09:26 +0100 | [diff] [blame] | 134 | memset(new_l1_table, 0, new_l1_size2); |
Kevin Wolf | de82815 | 2014-05-20 17:12:47 +0200 | [diff] [blame] | 135 | |
Stefan Hajnoczi | 0647d47 | 2016-09-13 09:56:27 +0100 | [diff] [blame] | 136 | if (s->l1_size) { |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 137 | memcpy(new_l1_table, s->l1_table, s->l1_size * L1E_SIZE); |
Stefan Hajnoczi | 0647d47 | 2016-09-13 09:56:27 +0100 | [diff] [blame] | 138 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 139 | |
| 140 | /* write new table (align to cluster) */ |
Kevin Wolf | 66f82ce | 2010-04-14 14:17:38 +0200 | [diff] [blame] | 141 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE); |
Kevin Wolf | ed6ccf0 | 2009-05-28 16:07:07 +0200 | [diff] [blame] | 142 | new_l1_table_offset = qcow2_alloc_clusters(bs, new_l1_size2); |
Kevin Wolf | 5d757b5 | 2010-01-20 15:04:01 +0100 | [diff] [blame] | 143 | if (new_l1_table_offset < 0) { |
Kevin Wolf | de82815 | 2014-05-20 17:12:47 +0200 | [diff] [blame] | 144 | qemu_vfree(new_l1_table); |
Kevin Wolf | 5d757b5 | 2010-01-20 15:04:01 +0100 | [diff] [blame] | 145 | return new_l1_table_offset; |
| 146 | } |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 147 | |
| 148 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
| 149 | if (ret < 0) { |
Kevin Wolf | 80fa334 | 2011-06-01 10:50:00 +0200 | [diff] [blame] | 150 | goto fail; |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 151 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 152 | |
Max Reitz | cf93980 | 2013-08-30 14:34:26 +0200 | [diff] [blame] | 153 | /* the L1 position has not yet been updated, so these clusters must |
| 154 | * indeed be completely free */ |
Max Reitz | 231bb26 | 2013-10-10 11:09:23 +0200 | [diff] [blame] | 155 | ret = qcow2_pre_write_overlap_check(bs, 0, new_l1_table_offset, |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 156 | new_l1_size2, false); |
Max Reitz | cf93980 | 2013-08-30 14:34:26 +0200 | [diff] [blame] | 157 | if (ret < 0) { |
| 158 | goto fail; |
| 159 | } |
| 160 | |
Kevin Wolf | 66f82ce | 2010-04-14 14:17:38 +0200 | [diff] [blame] | 161 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 162 | for(i = 0; i < s->l1_size; i++) |
| 163 | new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
Alberto Faria | 32cc71d | 2022-06-09 16:27:36 +0100 | [diff] [blame] | 164 | ret = bdrv_pwrite_sync(bs->file, new_l1_table_offset, new_l1_size2, |
| 165 | new_l1_table, 0); |
Kevin Wolf | 8b3b720 | 2010-06-16 17:44:35 +0200 | [diff] [blame] | 166 | if (ret < 0) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 167 | goto fail; |
| 168 | for(i = 0; i < s->l1_size; i++) |
| 169 | new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
| 170 | |
| 171 | /* set new table */ |
Kevin Wolf | 66f82ce | 2010-04-14 14:17:38 +0200 | [diff] [blame] | 172 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE); |
Peter Maydell | f1f7a1d | 2016-06-16 17:06:17 +0100 | [diff] [blame] | 173 | stl_be_p(data, new_l1_size); |
Peter Maydell | e4ef9f4 | 2013-11-05 16:38:36 +0000 | [diff] [blame] | 174 | stq_be_p(data + 4, new_l1_table_offset); |
Alberto Faria | 32cc71d | 2022-06-09 16:27:36 +0100 | [diff] [blame] | 175 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_size), |
| 176 | sizeof(data), data, 0); |
Kevin Wolf | 8b3b720 | 2010-06-16 17:44:35 +0200 | [diff] [blame] | 177 | if (ret < 0) { |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 178 | goto fail; |
Kevin Wolf | fb8fa77 | 2010-01-20 15:02:58 +0100 | [diff] [blame] | 179 | } |
Kevin Wolf | de82815 | 2014-05-20 17:12:47 +0200 | [diff] [blame] | 180 | qemu_vfree(s->l1_table); |
Max Reitz | fda74f8 | 2013-09-30 17:57:21 +0200 | [diff] [blame] | 181 | old_l1_table_offset = s->l1_table_offset; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 182 | s->l1_table_offset = new_l1_table_offset; |
| 183 | s->l1_table = new_l1_table; |
Max Reitz | fda74f8 | 2013-09-30 17:57:21 +0200 | [diff] [blame] | 184 | old_l1_size = s->l1_size; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 185 | s->l1_size = new_l1_size; |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 186 | qcow2_free_clusters(bs, old_l1_table_offset, old_l1_size * L1E_SIZE, |
Max Reitz | fda74f8 | 2013-09-30 17:57:21 +0200 | [diff] [blame] | 187 | QCOW2_DISCARD_OTHER); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 188 | return 0; |
| 189 | fail: |
Kevin Wolf | de82815 | 2014-05-20 17:12:47 +0200 | [diff] [blame] | 190 | qemu_vfree(new_l1_table); |
Kevin Wolf | 6cfcb9b | 2013-06-19 13:44:18 +0200 | [diff] [blame] | 191 | qcow2_free_clusters(bs, new_l1_table_offset, new_l1_size2, |
| 192 | QCOW2_DISCARD_OTHER); |
Kevin Wolf | 8b3b720 | 2010-06-16 17:44:35 +0200 | [diff] [blame] | 193 | return ret; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 194 | } |
| 195 | |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 196 | /* |
| 197 | * l2_load |
| 198 | * |
Alberto Garcia | e2b5713 | 2018-02-05 16:33:15 +0200 | [diff] [blame] | 199 | * @bs: The BlockDriverState |
| 200 | * @offset: A guest offset, used to calculate what slice of the L2 |
| 201 | * table to load. |
| 202 | * @l2_offset: Offset to the L2 table in the image file. |
| 203 | * @l2_slice: Location to store the pointer to the L2 slice. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 204 | * |
Alberto Garcia | e2b5713 | 2018-02-05 16:33:15 +0200 | [diff] [blame] | 205 | * Loads a L2 slice into memory (L2 slices are the parts of L2 tables |
| 206 | * that are loaded by the qcow2 cache). If the slice is in the cache, |
| 207 | * the cache is used; otherwise the L2 slice is loaded from the image |
| 208 | * file. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 209 | */ |
Alberto Garcia | e2b5713 | 2018-02-05 16:33:15 +0200 | [diff] [blame] | 210 | static int l2_load(BlockDriverState *bs, uint64_t offset, |
| 211 | uint64_t l2_offset, uint64_t **l2_slice) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 212 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 213 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | c8fd855 | 2020-07-10 18:12:54 +0200 | [diff] [blame] | 214 | int start_of_slice = l2_entry_size(s) * |
Alberto Garcia | e2b5713 | 2018-02-05 16:33:15 +0200 | [diff] [blame] | 215 | (offset_to_l2_index(s, offset) - offset_to_l2_slice_index(s, offset)); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 216 | |
Alberto Garcia | e2b5713 | 2018-02-05 16:33:15 +0200 | [diff] [blame] | 217 | return qcow2_cache_get(bs, s->l2_table_cache, l2_offset + start_of_slice, |
| 218 | (void **)l2_slice); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 219 | } |
| 220 | |
| 221 | /* |
Alberto Garcia | da86f8c | 2020-01-18 20:09:28 +0100 | [diff] [blame] | 222 | * Writes an L1 entry to disk (note that depending on the alignment |
| 223 | * requirements this function may write more that just one entry in |
| 224 | * order to prevent bdrv_pwrite from performing a read-modify-write) |
Kevin Wolf | 6583e3c | 2009-06-16 11:31:28 +0200 | [diff] [blame] | 225 | */ |
Max Reitz | e23e400 | 2013-08-30 14:34:28 +0200 | [diff] [blame] | 226 | int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index) |
Kevin Wolf | 6583e3c | 2009-06-16 11:31:28 +0200 | [diff] [blame] | 227 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 228 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 6583e3c | 2009-06-16 11:31:28 +0200 | [diff] [blame] | 229 | int l1_start_index; |
Kevin Wolf | f7defcb | 2010-03-23 17:28:22 +0100 | [diff] [blame] | 230 | int i, ret; |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 231 | int bufsize = MAX(L1E_SIZE, |
Alberto Garcia | da86f8c | 2020-01-18 20:09:28 +0100 | [diff] [blame] | 232 | MIN(bs->file->bs->bl.request_alignment, s->cluster_size)); |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 233 | int nentries = bufsize / L1E_SIZE; |
Alberto Garcia | da86f8c | 2020-01-18 20:09:28 +0100 | [diff] [blame] | 234 | g_autofree uint64_t *buf = g_try_new0(uint64_t, nentries); |
Kevin Wolf | 6583e3c | 2009-06-16 11:31:28 +0200 | [diff] [blame] | 235 | |
Alberto Garcia | da86f8c | 2020-01-18 20:09:28 +0100 | [diff] [blame] | 236 | if (buf == NULL) { |
| 237 | return -ENOMEM; |
| 238 | } |
| 239 | |
| 240 | l1_start_index = QEMU_ALIGN_DOWN(l1_index, nentries); |
| 241 | for (i = 0; i < MIN(nentries, s->l1_size - l1_start_index); i++) { |
Kevin Wolf | 6583e3c | 2009-06-16 11:31:28 +0200 | [diff] [blame] | 242 | buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); |
| 243 | } |
| 244 | |
Max Reitz | 231bb26 | 2013-10-10 11:09:23 +0200 | [diff] [blame] | 245 | ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1, |
Alberto Garcia | c508c73 | 2020-09-28 18:23:33 +0200 | [diff] [blame] | 246 | s->l1_table_offset + L1E_SIZE * l1_start_index, bufsize, false); |
Max Reitz | cf93980 | 2013-08-30 14:34:26 +0200 | [diff] [blame] | 247 | if (ret < 0) { |
| 248 | return ret; |
| 249 | } |
| 250 | |
Kevin Wolf | 66f82ce | 2010-04-14 14:17:38 +0200 | [diff] [blame] | 251 | BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); |
Kevin Wolf | d9ca2ea | 2016-06-20 20:09:15 +0200 | [diff] [blame] | 252 | ret = bdrv_pwrite_sync(bs->file, |
Alberto Garcia | c508c73 | 2020-09-28 18:23:33 +0200 | [diff] [blame] | 253 | s->l1_table_offset + L1E_SIZE * l1_start_index, |
Alberto Faria | 32cc71d | 2022-06-09 16:27:36 +0100 | [diff] [blame] | 254 | bufsize, buf, 0); |
Kevin Wolf | f7defcb | 2010-03-23 17:28:22 +0100 | [diff] [blame] | 255 | if (ret < 0) { |
| 256 | return ret; |
Kevin Wolf | 6583e3c | 2009-06-16 11:31:28 +0200 | [diff] [blame] | 257 | } |
| 258 | |
| 259 | return 0; |
| 260 | } |
| 261 | |
| 262 | /* |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 263 | * l2_allocate |
| 264 | * |
| 265 | * Allocate a new l2 entry in the file. If l1_index points to an already |
| 266 | * used entry in the L2 table (i.e. we are doing a copy on write for the L2 |
| 267 | * table) copy the contents of the old L2 table into the newly allocated one. |
| 268 | * Otherwise the new table is initialized with zeros. |
| 269 | * |
| 270 | */ |
| 271 | |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 272 | static int l2_allocate(BlockDriverState *bs, int l1_index) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 273 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 274 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 6583e3c | 2009-06-16 11:31:28 +0200 | [diff] [blame] | 275 | uint64_t old_l2_offset; |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 276 | uint64_t *l2_slice = NULL; |
| 277 | unsigned slice, slice_size2, n_slices; |
Kevin Wolf | f4f0d39 | 2010-02-02 15:20:57 +0100 | [diff] [blame] | 278 | int64_t l2_offset; |
Kevin Wolf | c46e116 | 2010-03-23 17:41:24 +0100 | [diff] [blame] | 279 | int ret; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 280 | |
| 281 | old_l2_offset = s->l1_table[l1_index]; |
| 282 | |
Kevin Wolf | 3cce16f | 2012-03-01 18:36:21 +0100 | [diff] [blame] | 283 | trace_qcow2_l2_allocate(bs, l1_index); |
| 284 | |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 285 | /* allocate a new l2 entry */ |
| 286 | |
Alberto Garcia | c8fd855 | 2020-07-10 18:12:54 +0200 | [diff] [blame] | 287 | l2_offset = qcow2_alloc_clusters(bs, s->l2_size * l2_entry_size(s)); |
Kevin Wolf | 5d757b5 | 2010-01-20 15:04:01 +0100 | [diff] [blame] | 288 | if (l2_offset < 0) { |
Max Reitz | be0b742 | 2013-09-25 16:37:20 +0200 | [diff] [blame] | 289 | ret = l2_offset; |
| 290 | goto fail; |
Kevin Wolf | 5d757b5 | 2010-01-20 15:04:01 +0100 | [diff] [blame] | 291 | } |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 292 | |
Alberto Garcia | c1c4399 | 2019-02-08 17:44:53 +0200 | [diff] [blame] | 293 | /* The offset must fit in the offset field of the L1 table entry */ |
| 294 | assert((l2_offset & L1E_OFFSET_MASK) == l2_offset); |
| 295 | |
Alberto Garcia | 9883975 | 2017-11-03 16:18:51 +0200 | [diff] [blame] | 296 | /* If we're allocating the table at offset 0 then something is wrong */ |
| 297 | if (l2_offset == 0) { |
| 298 | qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid " |
| 299 | "allocation of L2 table at offset 0"); |
| 300 | ret = -EIO; |
| 301 | goto fail; |
| 302 | } |
| 303 | |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 304 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
| 305 | if (ret < 0) { |
| 306 | goto fail; |
| 307 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 308 | |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 309 | /* allocate a new entry in the l2 cache */ |
| 310 | |
Alberto Garcia | c8fd855 | 2020-07-10 18:12:54 +0200 | [diff] [blame] | 311 | slice_size2 = s->l2_slice_size * l2_entry_size(s); |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 312 | n_slices = s->cluster_size / slice_size2; |
| 313 | |
Kevin Wolf | 3cce16f | 2012-03-01 18:36:21 +0100 | [diff] [blame] | 314 | trace_qcow2_l2_allocate_get_empty(bs, l1_index); |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 315 | for (slice = 0; slice < n_slices; slice++) { |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 316 | ret = qcow2_cache_get_empty(bs, s->l2_table_cache, |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 317 | l2_offset + slice * slice_size2, |
| 318 | (void **) &l2_slice); |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 319 | if (ret < 0) { |
| 320 | goto fail; |
| 321 | } |
| 322 | |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 323 | if ((old_l2_offset & L1E_OFFSET_MASK) == 0) { |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 324 | /* if there was no old l2 table, clear the new slice */ |
| 325 | memset(l2_slice, 0, slice_size2); |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 326 | } else { |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 327 | uint64_t *old_slice; |
| 328 | uint64_t old_l2_slice_offset = |
| 329 | (old_l2_offset & L1E_OFFSET_MASK) + slice * slice_size2; |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 330 | |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 331 | /* if there was an old l2 table, read a slice from the disk */ |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 332 | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_COW_READ); |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 333 | ret = qcow2_cache_get(bs, s->l2_table_cache, old_l2_slice_offset, |
| 334 | (void **) &old_slice); |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 335 | if (ret < 0) { |
| 336 | goto fail; |
| 337 | } |
| 338 | |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 339 | memcpy(l2_slice, old_slice, slice_size2); |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 340 | |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 341 | qcow2_cache_put(s->l2_table_cache, (void **) &old_slice); |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 342 | } |
| 343 | |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 344 | /* write the l2 slice to the file */ |
Alberto Garcia | 6580bb0 | 2018-02-05 16:33:16 +0200 | [diff] [blame] | 345 | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE); |
| 346 | |
| 347 | trace_qcow2_l2_allocate_write_l2(bs, l1_index); |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 348 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); |
| 349 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 350 | } |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 351 | |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 352 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
Kevin Wolf | c46e116 | 2010-03-23 17:41:24 +0100 | [diff] [blame] | 353 | if (ret < 0) { |
Kevin Wolf | 175e115 | 2010-05-12 16:23:26 +0200 | [diff] [blame] | 354 | goto fail; |
| 355 | } |
| 356 | |
| 357 | /* update the L1 entry */ |
Kevin Wolf | 3cce16f | 2012-03-01 18:36:21 +0100 | [diff] [blame] | 358 | trace_qcow2_l2_allocate_write_l1(bs, l1_index); |
Kevin Wolf | 175e115 | 2010-05-12 16:23:26 +0200 | [diff] [blame] | 359 | s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
Max Reitz | e23e400 | 2013-08-30 14:34:28 +0200 | [diff] [blame] | 360 | ret = qcow2_write_l1_entry(bs, l1_index); |
Kevin Wolf | 175e115 | 2010-05-12 16:23:26 +0200 | [diff] [blame] | 361 | if (ret < 0) { |
| 362 | goto fail; |
Kevin Wolf | c46e116 | 2010-03-23 17:41:24 +0100 | [diff] [blame] | 363 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 364 | |
Kevin Wolf | 3cce16f | 2012-03-01 18:36:21 +0100 | [diff] [blame] | 365 | trace_qcow2_l2_allocate_done(bs, l1_index, 0); |
Kevin Wolf | c46e116 | 2010-03-23 17:41:24 +0100 | [diff] [blame] | 366 | return 0; |
Kevin Wolf | 175e115 | 2010-05-12 16:23:26 +0200 | [diff] [blame] | 367 | |
| 368 | fail: |
Kevin Wolf | 3cce16f | 2012-03-01 18:36:21 +0100 | [diff] [blame] | 369 | trace_qcow2_l2_allocate_done(bs, l1_index, ret); |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 370 | if (l2_slice != NULL) { |
| 371 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Max Reitz | 8585afd | 2013-09-25 16:37:18 +0200 | [diff] [blame] | 372 | } |
Kevin Wolf | 68dba0b | 2010-06-07 16:43:22 +0200 | [diff] [blame] | 373 | s->l1_table[l1_index] = old_l2_offset; |
Max Reitz | e3b21ef | 2013-09-25 16:37:19 +0200 | [diff] [blame] | 374 | if (l2_offset > 0) { |
Alberto Garcia | c8fd855 | 2020-07-10 18:12:54 +0200 | [diff] [blame] | 375 | qcow2_free_clusters(bs, l2_offset, s->l2_size * l2_entry_size(s), |
Max Reitz | e3b21ef | 2013-09-25 16:37:19 +0200 | [diff] [blame] | 376 | QCOW2_DISCARD_ALWAYS); |
| 377 | } |
Kevin Wolf | 175e115 | 2010-05-12 16:23:26 +0200 | [diff] [blame] | 378 | return ret; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 379 | } |
| 380 | |
Kevin Wolf | 2bfcc4a | 2012-03-15 16:37:40 +0100 | [diff] [blame] | 381 | /* |
Alberto Garcia | 70d1cba | 2020-07-10 18:12:57 +0200 | [diff] [blame] | 382 | * For a given L2 entry, count the number of contiguous subclusters of |
| 383 | * the same type starting from @sc_from. Compressed clusters are |
| 384 | * treated as if they were divided into subclusters of size |
| 385 | * s->subcluster_size. |
| 386 | * |
| 387 | * Return the number of contiguous subclusters and set @type to the |
| 388 | * subcluster type. |
| 389 | * |
| 390 | * If the L2 entry is invalid return -errno and set @type to |
| 391 | * QCOW2_SUBCLUSTER_INVALID. |
| 392 | */ |
Alberto Garcia | 70d1cba | 2020-07-10 18:12:57 +0200 | [diff] [blame] | 393 | static int qcow2_get_subcluster_range_type(BlockDriverState *bs, |
| 394 | uint64_t l2_entry, |
| 395 | uint64_t l2_bitmap, |
| 396 | unsigned sc_from, |
| 397 | QCow2SubclusterType *type) |
| 398 | { |
| 399 | BDRVQcow2State *s = bs->opaque; |
| 400 | uint32_t val; |
| 401 | |
| 402 | *type = qcow2_get_subcluster_type(bs, l2_entry, l2_bitmap, sc_from); |
| 403 | |
| 404 | if (*type == QCOW2_SUBCLUSTER_INVALID) { |
| 405 | return -EINVAL; |
| 406 | } else if (!has_subclusters(s) || *type == QCOW2_SUBCLUSTER_COMPRESSED) { |
| 407 | return s->subclusters_per_cluster - sc_from; |
| 408 | } |
| 409 | |
| 410 | switch (*type) { |
| 411 | case QCOW2_SUBCLUSTER_NORMAL: |
| 412 | val = l2_bitmap | QCOW_OFLAG_SUB_ALLOC_RANGE(0, sc_from); |
| 413 | return cto32(val) - sc_from; |
| 414 | |
| 415 | case QCOW2_SUBCLUSTER_ZERO_PLAIN: |
| 416 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 417 | val = (l2_bitmap | QCOW_OFLAG_SUB_ZERO_RANGE(0, sc_from)) >> 32; |
| 418 | return cto32(val) - sc_from; |
| 419 | |
| 420 | case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: |
| 421 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: |
| 422 | val = ((l2_bitmap >> 32) | l2_bitmap) |
| 423 | & ~QCOW_OFLAG_SUB_ALLOC_RANGE(0, sc_from); |
| 424 | return ctz32(val) - sc_from; |
| 425 | |
| 426 | default: |
| 427 | g_assert_not_reached(); |
| 428 | } |
| 429 | } |
| 430 | |
| 431 | /* |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 432 | * Return the number of contiguous subclusters of the exact same type |
| 433 | * in a given L2 slice, starting from cluster @l2_index, subcluster |
| 434 | * @sc_index. Allocated subclusters are required to be contiguous in |
| 435 | * the image file. |
| 436 | * At most @nb_clusters are checked (note that this means clusters, |
| 437 | * not subclusters). |
| 438 | * Compressed clusters are always processed one by one but for the |
| 439 | * purpose of this count they are treated as if they were divided into |
| 440 | * subclusters of size s->subcluster_size. |
| 441 | * On failure return -errno and update @l2_index to point to the |
| 442 | * invalid entry. |
Kevin Wolf | 2bfcc4a | 2012-03-15 16:37:40 +0100 | [diff] [blame] | 443 | */ |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 444 | static int count_contiguous_subclusters(BlockDriverState *bs, int nb_clusters, |
| 445 | unsigned sc_index, uint64_t *l2_slice, |
| 446 | unsigned *l2_index) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 447 | { |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 448 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 449 | int i, count = 0; |
| 450 | bool check_offset = false; |
| 451 | uint64_t expected_offset = 0; |
| 452 | QCow2SubclusterType expected_type = QCOW2_SUBCLUSTER_NORMAL, type; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 453 | |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 454 | assert(*l2_index + nb_clusters <= s->l2_slice_size); |
Max Reitz | 15684a4 | 2013-09-27 12:14:15 +0200 | [diff] [blame] | 455 | |
Kevin Wolf | 6165300 | 2013-09-27 13:36:11 +0200 | [diff] [blame] | 456 | for (i = 0; i < nb_clusters; i++) { |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 457 | unsigned first_sc = (i == 0) ? sc_index : 0; |
| 458 | uint64_t l2_entry = get_l2_entry(s, l2_slice, *l2_index + i); |
| 459 | uint64_t l2_bitmap = get_l2_bitmap(s, l2_slice, *l2_index + i); |
| 460 | int ret = qcow2_get_subcluster_range_type(bs, l2_entry, l2_bitmap, |
| 461 | first_sc, &type); |
| 462 | if (ret < 0) { |
| 463 | *l2_index += i; /* Point to the invalid entry */ |
| 464 | return -EIO; |
| 465 | } |
| 466 | if (i == 0) { |
| 467 | if (type == QCOW2_SUBCLUSTER_COMPRESSED) { |
| 468 | /* Compressed clusters are always processed one by one */ |
| 469 | return ret; |
| 470 | } |
| 471 | expected_type = type; |
| 472 | expected_offset = l2_entry & L2E_OFFSET_MASK; |
| 473 | check_offset = (type == QCOW2_SUBCLUSTER_NORMAL || |
| 474 | type == QCOW2_SUBCLUSTER_ZERO_ALLOC || |
| 475 | type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC); |
| 476 | } else if (type != expected_type) { |
| 477 | break; |
| 478 | } else if (check_offset) { |
| 479 | expected_offset += s->cluster_size; |
| 480 | if (expected_offset != (l2_entry & L2E_OFFSET_MASK)) { |
| 481 | break; |
| 482 | } |
| 483 | } |
| 484 | count += ret; |
| 485 | /* Stop if there are type changes before the end of the cluster */ |
| 486 | if (first_sc + ret < s->subclusters_per_cluster) { |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 487 | break; |
Kevin Wolf | 2bfcc4a | 2012-03-15 16:37:40 +0100 | [diff] [blame] | 488 | } |
| 489 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 490 | |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 491 | return count; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 492 | } |
| 493 | |
Kevin Wolf | 7b1fb72 | 2023-02-03 16:21:49 +0100 | [diff] [blame] | 494 | static int coroutine_fn GRAPH_RDLOCK |
| 495 | do_perform_cow_read(BlockDriverState *bs, uint64_t src_cluster_offset, |
| 496 | unsigned offset_in_cluster, QEMUIOVector *qiov) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 497 | { |
Kevin Wolf | aaa4d20 | 2016-06-01 15:21:05 +0200 | [diff] [blame] | 498 | int ret; |
Kevin Wolf | 1b9f149 | 2011-09-19 11:26:48 +0200 | [diff] [blame] | 499 | |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 500 | if (qiov->size == 0) { |
Alberto Garcia | 99450c6 | 2017-06-19 16:40:04 +0300 | [diff] [blame] | 501 | return 0; |
| 502 | } |
| 503 | |
Paolo Bonzini | 1736239 | 2023-06-01 13:51:45 +0200 | [diff] [blame] | 504 | BLKDBG_CO_EVENT(bs->file, BLKDBG_COW_READ); |
Stefan Hajnoczi | aef4acb | 2011-11-30 12:23:41 +0000 | [diff] [blame] | 505 | |
Max Reitz | dba2855 | 2014-03-10 23:44:07 +0100 | [diff] [blame] | 506 | if (!bs->drv) { |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 507 | return -ENOMEDIUM; |
Max Reitz | dba2855 | 2014-03-10 23:44:07 +0100 | [diff] [blame] | 508 | } |
| 509 | |
Vladimir Sementsov-Ogievskiy | f7ef38d | 2021-09-03 13:27:59 +0300 | [diff] [blame] | 510 | /* |
| 511 | * We never deal with requests that don't satisfy |
| 512 | * bdrv_check_qiov_request(), and aligning requests to clusters never |
| 513 | * breaks this condition. So, do some assertions before calling |
| 514 | * bs->drv->bdrv_co_preadv_part() which has int64_t arguments. |
| 515 | */ |
| 516 | assert(src_cluster_offset <= INT64_MAX); |
| 517 | assert(src_cluster_offset + offset_in_cluster <= INT64_MAX); |
Hanna Reitz | e7e588d | 2021-10-11 17:50:31 +0200 | [diff] [blame] | 518 | /* Cast qiov->size to uint64_t to silence a compiler warning on -m32 */ |
| 519 | assert((uint64_t)qiov->size <= INT64_MAX); |
Vladimir Sementsov-Ogievskiy | f7ef38d | 2021-09-03 13:27:59 +0300 | [diff] [blame] | 520 | bdrv_check_qiov_request(src_cluster_offset + offset_in_cluster, qiov->size, |
| 521 | qiov, 0, &error_abort); |
| 522 | /* |
| 523 | * Call .bdrv_co_readv() directly instead of using the public block-layer |
Stefan Hajnoczi | aef4acb | 2011-11-30 12:23:41 +0000 | [diff] [blame] | 524 | * interface. This avoids double I/O throttling and request tracking, |
| 525 | * which can lead to deadlock when block layer copy-on-read is enabled. |
| 526 | */ |
Vladimir Sementsov-Ogievskiy | df893d2 | 2019-06-04 19:15:13 +0300 | [diff] [blame] | 527 | ret = bs->drv->bdrv_co_preadv_part(bs, |
| 528 | src_cluster_offset + offset_in_cluster, |
| 529 | qiov->size, qiov, 0, 0); |
Kevin Wolf | 1b9f149 | 2011-09-19 11:26:48 +0200 | [diff] [blame] | 530 | if (ret < 0) { |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 531 | return ret; |
Kevin Wolf | 1b9f149 | 2011-09-19 11:26:48 +0200 | [diff] [blame] | 532 | } |
| 533 | |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 534 | return 0; |
| 535 | } |
| 536 | |
Kevin Wolf | b9b10c3 | 2023-02-03 16:21:50 +0100 | [diff] [blame] | 537 | static int coroutine_fn GRAPH_RDLOCK |
| 538 | do_perform_cow_write(BlockDriverState *bs, uint64_t cluster_offset, |
| 539 | unsigned offset_in_cluster, QEMUIOVector *qiov) |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 540 | { |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 541 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 542 | int ret; |
| 543 | |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 544 | if (qiov->size == 0) { |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 545 | return 0; |
| 546 | } |
| 547 | |
Max Reitz | 231bb26 | 2013-10-10 11:09:23 +0200 | [diff] [blame] | 548 | ret = qcow2_pre_write_overlap_check(bs, 0, |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 549 | cluster_offset + offset_in_cluster, qiov->size, true); |
Max Reitz | cf93980 | 2013-08-30 14:34:26 +0200 | [diff] [blame] | 550 | if (ret < 0) { |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 551 | return ret; |
Max Reitz | cf93980 | 2013-08-30 14:34:26 +0200 | [diff] [blame] | 552 | } |
| 553 | |
Paolo Bonzini | 1736239 | 2023-06-01 13:51:45 +0200 | [diff] [blame] | 554 | BLKDBG_CO_EVENT(bs->file, BLKDBG_COW_WRITE); |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 555 | ret = bdrv_co_pwritev(s->data_file, cluster_offset + offset_in_cluster, |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 556 | qiov->size, qiov, 0); |
Kevin Wolf | 1b9f149 | 2011-09-19 11:26:48 +0200 | [diff] [blame] | 557 | if (ret < 0) { |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 558 | return ret; |
Kevin Wolf | 1b9f149 | 2011-09-19 11:26:48 +0200 | [diff] [blame] | 559 | } |
| 560 | |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 561 | return 0; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 562 | } |
| 563 | |
| 564 | |
| 565 | /* |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 566 | * get_host_offset |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 567 | * |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 568 | * For a given offset of the virtual disk find the equivalent host |
| 569 | * offset in the qcow2 file and store it in *host_offset. Neither |
| 570 | * offset needs to be aligned to a cluster boundary. |
| 571 | * |
| 572 | * If the cluster is unallocated then *host_offset will be 0. |
Vladimir Sementsov-Ogievskiy | 9a3978a | 2021-09-14 15:24:46 +0300 | [diff] [blame] | 573 | * If the cluster is compressed then *host_offset will contain the l2 entry. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 574 | * |
Kevin Wolf | ecfe186 | 2016-05-31 16:13:07 +0200 | [diff] [blame] | 575 | * On entry, *bytes is the maximum number of contiguous bytes starting at |
| 576 | * offset that we are interested in. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 577 | * |
Kevin Wolf | ecfe186 | 2016-05-31 16:13:07 +0200 | [diff] [blame] | 578 | * On exit, *bytes is the number of bytes starting at offset that have the same |
Alberto Garcia | 10dabdc5 | 2020-07-10 18:13:00 +0200 | [diff] [blame] | 579 | * subcluster type and (if applicable) are stored contiguously in the image |
| 580 | * file. The subcluster type is stored in *subcluster_type. |
| 581 | * Compressed clusters are always processed one by one. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 582 | * |
Alberto Garcia | ca4a0bb | 2020-07-10 18:12:59 +0200 | [diff] [blame] | 583 | * Returns 0 on success, -errno in error cases. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 584 | */ |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 585 | int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset, |
Alberto Garcia | ca4a0bb | 2020-07-10 18:12:59 +0200 | [diff] [blame] | 586 | unsigned int *bytes, uint64_t *host_offset, |
Alberto Garcia | 10dabdc5 | 2020-07-10 18:13:00 +0200 | [diff] [blame] | 587 | QCow2SubclusterType *subcluster_type) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 588 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 589 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 590 | unsigned int l2_index, sc_index; |
| 591 | uint64_t l1_index, l2_offset, *l2_slice, l2_entry, l2_bitmap; |
| 592 | int sc; |
Max Reitz | c834cba | 2016-06-20 16:26:23 +0200 | [diff] [blame] | 593 | unsigned int offset_in_cluster; |
| 594 | uint64_t bytes_available, bytes_needed, nb_clusters; |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 595 | QCow2SubclusterType type; |
Kevin Wolf | 55c17e9 | 2010-05-21 18:25:20 +0200 | [diff] [blame] | 596 | int ret; |
Kevin Wolf | b2f65d6 | 2016-05-31 16:41:09 +0200 | [diff] [blame] | 597 | |
| 598 | offset_in_cluster = offset_into_cluster(s, offset); |
Kevin Wolf | ecfe186 | 2016-05-31 16:13:07 +0200 | [diff] [blame] | 599 | bytes_needed = (uint64_t) *bytes + offset_in_cluster; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 600 | |
Kevin Wolf | b2f65d6 | 2016-05-31 16:41:09 +0200 | [diff] [blame] | 601 | /* compute how many bytes there are between the start of the cluster |
Alberto Garcia | fd63003 | 2018-02-05 16:33:20 +0200 | [diff] [blame] | 602 | * containing offset and the end of the l2 slice that contains |
| 603 | * the entry pointing to it */ |
| 604 | bytes_available = |
| 605 | ((uint64_t) (s->l2_slice_size - offset_to_l2_slice_index(s, offset))) |
| 606 | << s->cluster_bits; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 607 | |
Kevin Wolf | b2f65d6 | 2016-05-31 16:41:09 +0200 | [diff] [blame] | 608 | if (bytes_needed > bytes_available) { |
| 609 | bytes_needed = bytes_available; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 610 | } |
| 611 | |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 612 | *host_offset = 0; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 613 | |
Daniel P. Berrange | b6af097 | 2015-08-26 12:17:13 +0100 | [diff] [blame] | 614 | /* seek to the l2 offset in the l1 table */ |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 615 | |
Alberto Garcia | 05b5b6e | 2018-02-05 16:33:12 +0200 | [diff] [blame] | 616 | l1_index = offset_to_l1_index(s, offset); |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 617 | if (l1_index >= s->l1_size) { |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 618 | type = QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 619 | goto out; |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 620 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 621 | |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 622 | l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK; |
| 623 | if (!l2_offset) { |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 624 | type = QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 625 | goto out; |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 626 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 627 | |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 628 | if (offset_into_cluster(s, l2_offset)) { |
| 629 | qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" PRIx64 |
| 630 | " unaligned (L1 index: %#" PRIx64 ")", |
| 631 | l2_offset, l1_index); |
| 632 | return -EIO; |
| 633 | } |
| 634 | |
Alberto Garcia | fd63003 | 2018-02-05 16:33:20 +0200 | [diff] [blame] | 635 | /* load the l2 slice in memory */ |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 636 | |
Alberto Garcia | fd63003 | 2018-02-05 16:33:20 +0200 | [diff] [blame] | 637 | ret = l2_load(bs, offset, l2_offset, &l2_slice); |
Kevin Wolf | 55c17e9 | 2010-05-21 18:25:20 +0200 | [diff] [blame] | 638 | if (ret < 0) { |
| 639 | return ret; |
Kevin Wolf | 1c46efa | 2010-05-21 17:59:36 +0200 | [diff] [blame] | 640 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 641 | |
| 642 | /* find the cluster offset for the given disk offset */ |
| 643 | |
Alberto Garcia | fd63003 | 2018-02-05 16:33:20 +0200 | [diff] [blame] | 644 | l2_index = offset_to_l2_slice_index(s, offset); |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 645 | sc_index = offset_to_sc_index(s, offset); |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 646 | l2_entry = get_l2_entry(s, l2_slice, l2_index); |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 647 | l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index); |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 648 | |
Kevin Wolf | b2f65d6 | 2016-05-31 16:41:09 +0200 | [diff] [blame] | 649 | nb_clusters = size_to_clusters(s, bytes_needed); |
Max Reitz | c834cba | 2016-06-20 16:26:23 +0200 | [diff] [blame] | 650 | /* bytes_needed <= *bytes + offset_in_cluster, both of which are unsigned |
| 651 | * integers; the minimum cluster size is 512, so this assertion is always |
| 652 | * true */ |
| 653 | assert(nb_clusters <= INT_MAX); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 654 | |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 655 | type = qcow2_get_subcluster_type(bs, l2_entry, l2_bitmap, sc_index); |
| 656 | if (s->qcow_version < 3 && (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || |
| 657 | type == QCOW2_SUBCLUSTER_ZERO_ALLOC)) { |
Eric Blake | fdfab37 | 2017-05-06 19:05:46 -0500 | [diff] [blame] | 658 | qcow2_signal_corruption(bs, true, -1, -1, "Zero cluster entry found" |
| 659 | " in pre-v3 image (L2 offset: %#" PRIx64 |
| 660 | ", L2 index: %#x)", l2_offset, l2_index); |
| 661 | ret = -EIO; |
| 662 | goto fail; |
| 663 | } |
Eric Blake | 3ef9521 | 2017-05-06 19:05:45 -0500 | [diff] [blame] | 664 | switch (type) { |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 665 | case QCOW2_SUBCLUSTER_INVALID: |
| 666 | break; /* This is handled by count_contiguous_subclusters() below */ |
| 667 | case QCOW2_SUBCLUSTER_COMPRESSED: |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 668 | if (has_data_file(bs)) { |
| 669 | qcow2_signal_corruption(bs, true, -1, -1, "Compressed cluster " |
| 670 | "entry found in image with external data " |
| 671 | "file (L2 offset: %#" PRIx64 ", L2 index: " |
| 672 | "%#x)", l2_offset, l2_index); |
| 673 | ret = -EIO; |
| 674 | goto fail; |
| 675 | } |
Vladimir Sementsov-Ogievskiy | 9a3978a | 2021-09-14 15:24:46 +0300 | [diff] [blame] | 676 | *host_offset = l2_entry; |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 677 | break; |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 678 | case QCOW2_SUBCLUSTER_ZERO_PLAIN: |
| 679 | case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 680 | break; |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 681 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 682 | case QCOW2_SUBCLUSTER_NORMAL: |
| 683 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: { |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 684 | uint64_t host_cluster_offset = l2_entry & L2E_OFFSET_MASK; |
| 685 | *host_offset = host_cluster_offset + offset_in_cluster; |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 686 | if (offset_into_cluster(s, host_cluster_offset)) { |
Eric Blake | fdfab37 | 2017-05-06 19:05:46 -0500 | [diff] [blame] | 687 | qcow2_signal_corruption(bs, true, -1, -1, |
| 688 | "Cluster allocation offset %#" |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 689 | PRIx64 " unaligned (L2 offset: %#" PRIx64 |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 690 | ", L2 index: %#x)", host_cluster_offset, |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 691 | l2_offset, l2_index); |
| 692 | ret = -EIO; |
| 693 | goto fail; |
| 694 | } |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 695 | if (has_data_file(bs) && *host_offset != offset) { |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 696 | qcow2_signal_corruption(bs, true, -1, -1, |
| 697 | "External data file host cluster offset %#" |
| 698 | PRIx64 " does not match guest cluster " |
| 699 | "offset: %#" PRIx64 |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 700 | ", L2 index: %#x)", host_cluster_offset, |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 701 | offset - offset_in_cluster, l2_index); |
| 702 | ret = -EIO; |
| 703 | goto fail; |
| 704 | } |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 705 | break; |
Alberto Garcia | 388e581 | 2020-07-10 18:12:44 +0200 | [diff] [blame] | 706 | } |
Kevin Wolf | 1417d7e | 2012-06-15 13:43:18 +0200 | [diff] [blame] | 707 | default: |
| 708 | abort(); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 709 | } |
| 710 | |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 711 | sc = count_contiguous_subclusters(bs, nb_clusters, sc_index, |
| 712 | l2_slice, &l2_index); |
| 713 | if (sc < 0) { |
| 714 | qcow2_signal_corruption(bs, true, -1, -1, "Invalid cluster entry found " |
| 715 | " (L2 offset: %#" PRIx64 ", L2 index: %#x)", |
| 716 | l2_offset, l2_index); |
| 717 | ret = -EIO; |
| 718 | goto fail; |
| 719 | } |
Alberto Garcia | fd63003 | 2018-02-05 16:33:20 +0200 | [diff] [blame] | 720 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 29c1a73 | 2011-01-10 17:17:28 +0100 | [diff] [blame] | 721 | |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 722 | bytes_available = ((int64_t)sc + sc_index) << s->subcluster_bits; |
Kevin Wolf | 68d000a | 2012-03-14 19:15:03 +0100 | [diff] [blame] | 723 | |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 724 | out: |
Kevin Wolf | b2f65d6 | 2016-05-31 16:41:09 +0200 | [diff] [blame] | 725 | if (bytes_available > bytes_needed) { |
| 726 | bytes_available = bytes_needed; |
| 727 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 728 | |
Max Reitz | c834cba | 2016-06-20 16:26:23 +0200 | [diff] [blame] | 729 | /* bytes_available <= bytes_needed <= *bytes + offset_in_cluster; |
| 730 | * subtracting offset_in_cluster will therefore definitely yield something |
| 731 | * not exceeding UINT_MAX */ |
| 732 | assert(bytes_available - offset_in_cluster <= UINT_MAX); |
Kevin Wolf | ecfe186 | 2016-05-31 16:13:07 +0200 | [diff] [blame] | 733 | *bytes = bytes_available - offset_in_cluster; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 734 | |
Alberto Garcia | 3f9c6b3 | 2020-07-10 18:13:03 +0200 | [diff] [blame] | 735 | *subcluster_type = type; |
Alberto Garcia | ca4a0bb | 2020-07-10 18:12:59 +0200 | [diff] [blame] | 736 | |
| 737 | return 0; |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 738 | |
| 739 | fail: |
Alberto Garcia | fd63003 | 2018-02-05 16:33:20 +0200 | [diff] [blame] | 740 | qcow2_cache_put(s->l2_table_cache, (void **)&l2_slice); |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 741 | return ret; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 742 | } |
| 743 | |
| 744 | /* |
| 745 | * get_cluster_table |
| 746 | * |
| 747 | * for a given disk offset, load (and allocate if needed) |
Alberto Garcia | c03bfc5 | 2018-02-05 16:33:19 +0200 | [diff] [blame] | 748 | * the appropriate slice of its l2 table. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 749 | * |
Alberto Garcia | c03bfc5 | 2018-02-05 16:33:19 +0200 | [diff] [blame] | 750 | * the cluster index in the l2 slice is given to the caller. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 751 | * |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 752 | * Returns 0 on success, -errno in failure case |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 753 | */ |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 754 | static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
Alberto Garcia | c03bfc5 | 2018-02-05 16:33:19 +0200 | [diff] [blame] | 755 | uint64_t **new_l2_slice, |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 756 | int *new_l2_index) |
| 757 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 758 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 2cf7cfa | 2013-05-14 16:14:33 +0200 | [diff] [blame] | 759 | unsigned int l2_index; |
| 760 | uint64_t l1_index, l2_offset; |
Alberto Garcia | c03bfc5 | 2018-02-05 16:33:19 +0200 | [diff] [blame] | 761 | uint64_t *l2_slice = NULL; |
Kevin Wolf | 80ee15a | 2009-09-15 12:30:43 +0200 | [diff] [blame] | 762 | int ret; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 763 | |
Daniel P. Berrange | b6af097 | 2015-08-26 12:17:13 +0100 | [diff] [blame] | 764 | /* seek to the l2 offset in the l1 table */ |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 765 | |
Alberto Garcia | 05b5b6e | 2018-02-05 16:33:12 +0200 | [diff] [blame] | 766 | l1_index = offset_to_l1_index(s, offset); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 767 | if (l1_index >= s->l1_size) { |
Stefan Hajnoczi | 7289375 | 2010-10-18 16:53:53 +0100 | [diff] [blame] | 768 | ret = qcow2_grow_l1_table(bs, l1_index + 1, false); |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 769 | if (ret < 0) { |
| 770 | return ret; |
| 771 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 772 | } |
Kevin Wolf | 8e37f68 | 2012-02-23 15:40:55 +0100 | [diff] [blame] | 773 | |
Kevin Wolf | 2cf7cfa | 2013-05-14 16:14:33 +0200 | [diff] [blame] | 774 | assert(l1_index < s->l1_size); |
Kevin Wolf | 8e37f68 | 2012-02-23 15:40:55 +0100 | [diff] [blame] | 775 | l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK; |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 776 | if (offset_into_cluster(s, l2_offset)) { |
| 777 | qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" PRIx64 |
| 778 | " unaligned (L1 index: %#" PRIx64 ")", |
| 779 | l2_offset, l1_index); |
| 780 | return -EIO; |
| 781 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 782 | |
Alberto Garcia | 05f9ee46 | 2018-02-05 16:33:18 +0200 | [diff] [blame] | 783 | if (!(s->l1_table[l1_index] & QCOW_OFLAG_COPIED)) { |
Kevin Wolf | 16fde5f | 2011-02-09 17:36:19 +0100 | [diff] [blame] | 784 | /* First allocate a new L2 table (and do COW if needed) */ |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 785 | ret = l2_allocate(bs, l1_index); |
Kevin Wolf | c46e116 | 2010-03-23 17:41:24 +0100 | [diff] [blame] | 786 | if (ret < 0) { |
| 787 | return ret; |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 788 | } |
Kevin Wolf | 16fde5f | 2011-02-09 17:36:19 +0100 | [diff] [blame] | 789 | |
| 790 | /* Then decrease the refcount of the old table */ |
| 791 | if (l2_offset) { |
Alberto Garcia | c8fd855 | 2020-07-10 18:12:54 +0200 | [diff] [blame] | 792 | qcow2_free_clusters(bs, l2_offset, s->l2_size * l2_entry_size(s), |
Kevin Wolf | 6cfcb9b | 2013-06-19 13:44:18 +0200 | [diff] [blame] | 793 | QCOW2_DISCARD_OTHER); |
Kevin Wolf | 16fde5f | 2011-02-09 17:36:19 +0100 | [diff] [blame] | 794 | } |
Alberto Garcia | 3861946 | 2018-02-05 16:33:17 +0200 | [diff] [blame] | 795 | |
| 796 | /* Get the offset of the newly-allocated l2 table */ |
| 797 | l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK; |
| 798 | assert(offset_into_cluster(s, l2_offset) == 0); |
Alberto Garcia | 05f9ee46 | 2018-02-05 16:33:18 +0200 | [diff] [blame] | 799 | } |
| 800 | |
Alberto Garcia | c03bfc5 | 2018-02-05 16:33:19 +0200 | [diff] [blame] | 801 | /* load the l2 slice in memory */ |
| 802 | ret = l2_load(bs, offset, l2_offset, &l2_slice); |
Alberto Garcia | 05f9ee46 | 2018-02-05 16:33:18 +0200 | [diff] [blame] | 803 | if (ret < 0) { |
| 804 | return ret; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 805 | } |
| 806 | |
| 807 | /* find the cluster offset for the given disk offset */ |
| 808 | |
Alberto Garcia | c03bfc5 | 2018-02-05 16:33:19 +0200 | [diff] [blame] | 809 | l2_index = offset_to_l2_slice_index(s, offset); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 810 | |
Alberto Garcia | c03bfc5 | 2018-02-05 16:33:19 +0200 | [diff] [blame] | 811 | *new_l2_slice = l2_slice; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 812 | *new_l2_index = l2_index; |
| 813 | |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 814 | return 0; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 815 | } |
| 816 | |
| 817 | /* |
| 818 | * alloc_compressed_cluster_offset |
| 819 | * |
Kevin Wolf | 77e023f | 2019-02-27 10:26:24 +0100 | [diff] [blame] | 820 | * For a given offset on the virtual disk, allocate a new compressed cluster |
| 821 | * and put the host offset of the cluster into *host_offset. If a cluster is |
| 822 | * already allocated at the offset, return an error. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 823 | * |
Kevin Wolf | 77e023f | 2019-02-27 10:26:24 +0100 | [diff] [blame] | 824 | * Return 0 on success and -errno in error cases |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 825 | */ |
Paolo Bonzini | 70bacc4 | 2023-06-01 13:51:43 +0200 | [diff] [blame] | 826 | int coroutine_fn GRAPH_RDLOCK |
| 827 | qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, uint64_t offset, |
| 828 | int compressed_size, uint64_t *host_offset) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 829 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 830 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 831 | int l2_index, ret; |
Alberto Garcia | e4e7254 | 2018-02-05 16:33:32 +0200 | [diff] [blame] | 832 | uint64_t *l2_slice; |
Kevin Wolf | f4f0d39 | 2010-02-02 15:20:57 +0100 | [diff] [blame] | 833 | int64_t cluster_offset; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 834 | int nb_csectors; |
| 835 | |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 836 | if (has_data_file(bs)) { |
| 837 | return 0; |
| 838 | } |
| 839 | |
Alberto Garcia | e4e7254 | 2018-02-05 16:33:32 +0200 | [diff] [blame] | 840 | ret = get_cluster_table(bs, offset, &l2_slice, &l2_index); |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 841 | if (ret < 0) { |
Kevin Wolf | 77e023f | 2019-02-27 10:26:24 +0100 | [diff] [blame] | 842 | return ret; |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 843 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 844 | |
Kevin Wolf | b0b6862 | 2012-03-15 17:20:11 +0100 | [diff] [blame] | 845 | /* Compression can't overwrite anything. Fail if the cluster was already |
| 846 | * allocated. */ |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 847 | cluster_offset = get_l2_entry(s, l2_slice, l2_index); |
Kevin Wolf | b0b6862 | 2012-03-15 17:20:11 +0100 | [diff] [blame] | 848 | if (cluster_offset & L2E_OFFSET_MASK) { |
Alberto Garcia | e4e7254 | 2018-02-05 16:33:32 +0200 | [diff] [blame] | 849 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 77e023f | 2019-02-27 10:26:24 +0100 | [diff] [blame] | 850 | return -EIO; |
Kevin Wolf | 8f1efd0 | 2011-10-18 17:12:44 +0200 | [diff] [blame] | 851 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 852 | |
Kevin Wolf | ed6ccf0 | 2009-05-28 16:07:07 +0200 | [diff] [blame] | 853 | cluster_offset = qcow2_alloc_bytes(bs, compressed_size); |
Kevin Wolf | 5d757b5 | 2010-01-20 15:04:01 +0100 | [diff] [blame] | 854 | if (cluster_offset < 0) { |
Alberto Garcia | e4e7254 | 2018-02-05 16:33:32 +0200 | [diff] [blame] | 855 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 77e023f | 2019-02-27 10:26:24 +0100 | [diff] [blame] | 856 | return cluster_offset; |
Kevin Wolf | 5d757b5 | 2010-01-20 15:04:01 +0100 | [diff] [blame] | 857 | } |
| 858 | |
Alberto Garcia | b6c2469 | 2019-05-10 19:22:54 +0300 | [diff] [blame] | 859 | nb_csectors = |
| 860 | (cluster_offset + compressed_size - 1) / QCOW2_COMPRESSED_SECTOR_SIZE - |
| 861 | (cluster_offset / QCOW2_COMPRESSED_SECTOR_SIZE); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 862 | |
Alberto Garcia | 3a75a87 | 2020-01-13 17:11:46 +0100 | [diff] [blame] | 863 | /* The offset and size must fit in their fields of the L2 table entry */ |
| 864 | assert((cluster_offset & s->cluster_offset_mask) == cluster_offset); |
| 865 | assert((nb_csectors & s->csize_mask) == nb_csectors); |
| 866 | |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 867 | cluster_offset |= QCOW_OFLAG_COMPRESSED | |
| 868 | ((uint64_t)nb_csectors << s->csize_shift); |
| 869 | |
| 870 | /* update L2 table */ |
| 871 | |
| 872 | /* compressed clusters never have the copied flag */ |
| 873 | |
Paolo Bonzini | 1736239 | 2023-06-01 13:51:45 +0200 | [diff] [blame] | 874 | BLKDBG_CO_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED); |
Alberto Garcia | e4e7254 | 2018-02-05 16:33:32 +0200 | [diff] [blame] | 875 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 876 | set_l2_entry(s, l2_slice, l2_index, cluster_offset); |
Alberto Garcia | ff4cdec | 2020-07-10 18:13:08 +0200 | [diff] [blame] | 877 | if (has_subclusters(s)) { |
| 878 | set_l2_bitmap(s, l2_slice, l2_index, 0); |
| 879 | } |
Alberto Garcia | e4e7254 | 2018-02-05 16:33:32 +0200 | [diff] [blame] | 880 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 4c1612d | 2009-06-16 11:31:29 +0200 | [diff] [blame] | 881 | |
Kevin Wolf | 77e023f | 2019-02-27 10:26:24 +0100 | [diff] [blame] | 882 | *host_offset = cluster_offset & s->cluster_offset_mask; |
| 883 | return 0; |
Kevin Wolf | 4c1612d | 2009-06-16 11:31:29 +0200 | [diff] [blame] | 884 | } |
| 885 | |
Kevin Wolf | 7b1fb72 | 2023-02-03 16:21:49 +0100 | [diff] [blame] | 886 | static int coroutine_fn GRAPH_RDLOCK |
| 887 | perform_cow(BlockDriverState *bs, QCowL2Meta *m) |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 888 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 889 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | 99450c6 | 2017-06-19 16:40:04 +0300 | [diff] [blame] | 890 | Qcow2COWRegion *start = &m->cow_start; |
| 891 | Qcow2COWRegion *end = &m->cow_end; |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 892 | unsigned buffer_size; |
Alberto Garcia | b3cf1c7 | 2017-06-19 16:40:06 +0300 | [diff] [blame] | 893 | unsigned data_bytes = end->offset - (start->offset + start->nb_bytes); |
| 894 | bool merge_reads; |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 895 | uint8_t *start_buffer, *end_buffer; |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 896 | QEMUIOVector qiov; |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 897 | int ret; |
| 898 | |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 899 | assert(start->nb_bytes <= UINT_MAX - end->nb_bytes); |
Alberto Garcia | b3cf1c7 | 2017-06-19 16:40:06 +0300 | [diff] [blame] | 900 | assert(start->nb_bytes + end->nb_bytes <= UINT_MAX - data_bytes); |
| 901 | assert(start->offset + start->nb_bytes <= end->offset); |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 902 | |
Anton Nefedov | c8bb23c | 2019-05-16 17:27:49 +0300 | [diff] [blame] | 903 | if ((start->nb_bytes == 0 && end->nb_bytes == 0) || m->skip_cow) { |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 904 | return 0; |
| 905 | } |
| 906 | |
Alberto Garcia | b3cf1c7 | 2017-06-19 16:40:06 +0300 | [diff] [blame] | 907 | /* If we have to read both the start and end COW regions and the |
| 908 | * middle region is not too large then perform just one read |
| 909 | * operation */ |
| 910 | merge_reads = start->nb_bytes && end->nb_bytes && data_bytes <= 16384; |
| 911 | if (merge_reads) { |
| 912 | buffer_size = start->nb_bytes + data_bytes + end->nb_bytes; |
| 913 | } else { |
| 914 | /* If we have to do two reads, add some padding in the middle |
| 915 | * if necessary to make sure that the end region is optimally |
| 916 | * aligned. */ |
| 917 | size_t align = bdrv_opt_mem_align(bs); |
| 918 | assert(align > 0 && align <= UINT_MAX); |
| 919 | assert(QEMU_ALIGN_UP(start->nb_bytes, align) <= |
| 920 | UINT_MAX - end->nb_bytes); |
| 921 | buffer_size = QEMU_ALIGN_UP(start->nb_bytes, align) + end->nb_bytes; |
| 922 | } |
| 923 | |
| 924 | /* Reserve a buffer large enough to store all the data that we're |
| 925 | * going to read */ |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 926 | start_buffer = qemu_try_blockalign(bs, buffer_size); |
| 927 | if (start_buffer == NULL) { |
| 928 | return -ENOMEM; |
| 929 | } |
| 930 | /* The part of the buffer where the end region is located */ |
| 931 | end_buffer = start_buffer + buffer_size - end->nb_bytes; |
| 932 | |
Vladimir Sementsov-Ogievskiy | 5396234 | 2019-06-04 19:15:14 +0300 | [diff] [blame] | 933 | qemu_iovec_init(&qiov, 2 + (m->data_qiov ? |
| 934 | qemu_iovec_subvec_niov(m->data_qiov, |
| 935 | m->data_qiov_offset, |
| 936 | data_bytes) |
| 937 | : 0)); |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 938 | |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 939 | qemu_co_mutex_unlock(&s->lock); |
Alberto Garcia | b3cf1c7 | 2017-06-19 16:40:06 +0300 | [diff] [blame] | 940 | /* First we read the existing data from both COW regions. We |
| 941 | * either read the whole region in one go, or the start and end |
| 942 | * regions separately. */ |
| 943 | if (merge_reads) { |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 944 | qemu_iovec_add(&qiov, start_buffer, buffer_size); |
| 945 | ret = do_perform_cow_read(bs, m->offset, start->offset, &qiov); |
Alberto Garcia | b3cf1c7 | 2017-06-19 16:40:06 +0300 | [diff] [blame] | 946 | } else { |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 947 | qemu_iovec_add(&qiov, start_buffer, start->nb_bytes); |
| 948 | ret = do_perform_cow_read(bs, m->offset, start->offset, &qiov); |
Alberto Garcia | b3cf1c7 | 2017-06-19 16:40:06 +0300 | [diff] [blame] | 949 | if (ret < 0) { |
| 950 | goto fail; |
| 951 | } |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 952 | |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 953 | qemu_iovec_reset(&qiov); |
| 954 | qemu_iovec_add(&qiov, end_buffer, end->nb_bytes); |
| 955 | ret = do_perform_cow_read(bs, m->offset, end->offset, &qiov); |
Alberto Garcia | b3cf1c7 | 2017-06-19 16:40:06 +0300 | [diff] [blame] | 956 | } |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 957 | if (ret < 0) { |
| 958 | goto fail; |
| 959 | } |
Alberto Garcia | 99450c6 | 2017-06-19 16:40:04 +0300 | [diff] [blame] | 960 | |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 961 | /* Encrypt the data if necessary before writing it */ |
| 962 | if (bs->encrypted) { |
Maxim Levitsky | 603fbd0 | 2019-09-15 23:36:54 +0300 | [diff] [blame] | 963 | ret = qcow2_co_encrypt(bs, |
| 964 | m->alloc_offset + start->offset, |
| 965 | m->offset + start->offset, |
| 966 | start_buffer, start->nb_bytes); |
| 967 | if (ret < 0) { |
| 968 | goto fail; |
| 969 | } |
| 970 | |
| 971 | ret = qcow2_co_encrypt(bs, |
| 972 | m->alloc_offset + end->offset, |
| 973 | m->offset + end->offset, |
| 974 | end_buffer, end->nb_bytes); |
| 975 | if (ret < 0) { |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 976 | goto fail; |
| 977 | } |
| 978 | } |
| 979 | |
Alberto Garcia | ee22a9d | 2017-06-19 16:40:08 +0300 | [diff] [blame] | 980 | /* And now we can write everything. If we have the guest data we |
| 981 | * can write everything in one single operation */ |
| 982 | if (m->data_qiov) { |
| 983 | qemu_iovec_reset(&qiov); |
| 984 | if (start->nb_bytes) { |
| 985 | qemu_iovec_add(&qiov, start_buffer, start->nb_bytes); |
| 986 | } |
Vladimir Sementsov-Ogievskiy | 5396234 | 2019-06-04 19:15:14 +0300 | [diff] [blame] | 987 | qemu_iovec_concat(&qiov, m->data_qiov, m->data_qiov_offset, data_bytes); |
Alberto Garcia | ee22a9d | 2017-06-19 16:40:08 +0300 | [diff] [blame] | 988 | if (end->nb_bytes) { |
| 989 | qemu_iovec_add(&qiov, end_buffer, end->nb_bytes); |
| 990 | } |
| 991 | /* NOTE: we have a write_aio blkdebug event here followed by |
| 992 | * a cow_write one in do_perform_cow_write(), but there's only |
| 993 | * one single I/O operation */ |
Paolo Bonzini | 1736239 | 2023-06-01 13:51:45 +0200 | [diff] [blame] | 994 | BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); |
Alberto Garcia | ee22a9d | 2017-06-19 16:40:08 +0300 | [diff] [blame] | 995 | ret = do_perform_cow_write(bs, m->alloc_offset, start->offset, &qiov); |
| 996 | } else { |
| 997 | /* If there's no guest data then write both COW regions separately */ |
| 998 | qemu_iovec_reset(&qiov); |
| 999 | qemu_iovec_add(&qiov, start_buffer, start->nb_bytes); |
| 1000 | ret = do_perform_cow_write(bs, m->alloc_offset, start->offset, &qiov); |
| 1001 | if (ret < 0) { |
| 1002 | goto fail; |
| 1003 | } |
| 1004 | |
| 1005 | qemu_iovec_reset(&qiov); |
| 1006 | qemu_iovec_add(&qiov, end_buffer, end->nb_bytes); |
| 1007 | ret = do_perform_cow_write(bs, m->alloc_offset, end->offset, &qiov); |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 1008 | } |
| 1009 | |
Alberto Garcia | 99450c6 | 2017-06-19 16:40:04 +0300 | [diff] [blame] | 1010 | fail: |
| 1011 | qemu_co_mutex_lock(&s->lock); |
| 1012 | |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 1013 | /* |
| 1014 | * Before we update the L2 table to actually point to the new cluster, we |
| 1015 | * need to be sure that the refcounts have been increased and COW was |
| 1016 | * handled. |
| 1017 | */ |
Alberto Garcia | 99450c6 | 2017-06-19 16:40:04 +0300 | [diff] [blame] | 1018 | if (ret == 0) { |
| 1019 | qcow2_cache_depends_on_flush(s->l2_table_cache); |
| 1020 | } |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 1021 | |
Alberto Garcia | 672f0f2 | 2017-06-19 16:40:05 +0300 | [diff] [blame] | 1022 | qemu_vfree(start_buffer); |
Alberto Garcia | 86b862c | 2017-06-19 16:40:07 +0300 | [diff] [blame] | 1023 | qemu_iovec_destroy(&qiov); |
Alberto Garcia | 99450c6 | 2017-06-19 16:40:04 +0300 | [diff] [blame] | 1024 | return ret; |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 1025 | } |
| 1026 | |
Paolo Bonzini | 050ed2e | 2022-09-22 10:49:12 +0200 | [diff] [blame] | 1027 | int coroutine_fn qcow2_alloc_cluster_link_l2(BlockDriverState *bs, |
| 1028 | QCowL2Meta *m) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1029 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1030 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1031 | int i, j = 0, l2_index, ret; |
Alberto Garcia | a002c0b | 2018-02-05 16:33:21 +0200 | [diff] [blame] | 1032 | uint64_t *old_cluster, *l2_slice; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1033 | uint64_t cluster_offset = m->alloc_offset; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1034 | |
Kevin Wolf | 3cce16f | 2012-03-01 18:36:21 +0100 | [diff] [blame] | 1035 | trace_qcow2_cluster_link_l2(qemu_coroutine_self(), m->nb_clusters); |
Kevin Wolf | f50f88b | 2012-12-07 18:08:46 +0100 | [diff] [blame] | 1036 | assert(m->nb_clusters > 0); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1037 | |
Markus Armbruster | 5839e53 | 2014-08-19 10:31:08 +0200 | [diff] [blame] | 1038 | old_cluster = g_try_new(uint64_t, m->nb_clusters); |
Kevin Wolf | de82815 | 2014-05-20 17:12:47 +0200 | [diff] [blame] | 1039 | if (old_cluster == NULL) { |
| 1040 | ret = -ENOMEM; |
| 1041 | goto err; |
| 1042 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1043 | |
| 1044 | /* copy content of unmodified sectors */ |
Alberto Garcia | 99450c6 | 2017-06-19 16:40:04 +0300 | [diff] [blame] | 1045 | ret = perform_cow(bs, m); |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 1046 | if (ret < 0) { |
| 1047 | goto err; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1048 | } |
| 1049 | |
Kevin Wolf | 593fb83 | 2012-12-07 18:08:43 +0100 | [diff] [blame] | 1050 | /* Update L2 table. */ |
Kevin Wolf | 74c4510 | 2013-03-15 10:35:08 +0100 | [diff] [blame] | 1051 | if (s->use_lazy_refcounts) { |
Kevin Wolf | 280d373 | 2012-12-07 18:08:47 +0100 | [diff] [blame] | 1052 | qcow2_mark_dirty(bs); |
| 1053 | } |
Stefan Hajnoczi | bfe8043 | 2012-07-27 09:05:22 +0100 | [diff] [blame] | 1054 | if (qcow2_need_accurate_refcounts(s)) { |
| 1055 | qcow2_cache_set_dependency(bs, s->l2_table_cache, |
| 1056 | s->refcount_block_cache); |
| 1057 | } |
Kevin Wolf | 280d373 | 2012-12-07 18:08:47 +0100 | [diff] [blame] | 1058 | |
Alberto Garcia | a002c0b | 2018-02-05 16:33:21 +0200 | [diff] [blame] | 1059 | ret = get_cluster_table(bs, m->offset, &l2_slice, &l2_index); |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 1060 | if (ret < 0) { |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1061 | goto err; |
Kevin Wolf | 1e3e8f1 | 2010-01-20 15:03:00 +0100 | [diff] [blame] | 1062 | } |
Alberto Garcia | a002c0b | 2018-02-05 16:33:21 +0200 | [diff] [blame] | 1063 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1064 | |
Alberto Garcia | a002c0b | 2018-02-05 16:33:21 +0200 | [diff] [blame] | 1065 | assert(l2_index + m->nb_clusters <= s->l2_slice_size); |
Alberto Garcia | 3441ad4 | 2020-10-07 18:13:23 +0200 | [diff] [blame] | 1066 | assert(m->cow_end.offset + m->cow_end.nb_bytes <= |
| 1067 | m->nb_clusters << s->cluster_bits); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1068 | for (i = 0; i < m->nb_clusters; i++) { |
Tuguoyi | 348fcc4 | 2020-08-05 09:22:58 +0000 | [diff] [blame] | 1069 | uint64_t offset = cluster_offset + ((uint64_t)i << s->cluster_bits); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1070 | /* if two concurrent writes happen to the same unallocated cluster |
Kevin Wolf | aaa4d20 | 2016-06-01 15:21:05 +0200 | [diff] [blame] | 1071 | * each write allocates separate cluster and writes data concurrently. |
| 1072 | * The first one to complete updates l2 table with pointer to its |
| 1073 | * cluster the second one has to do RMW (which is done above by |
| 1074 | * perform_cow()), update l2 table with its cluster pointer and free |
| 1075 | * old cluster. This is what this loop does */ |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 1076 | if (get_l2_entry(s, l2_slice, l2_index + i) != 0) { |
| 1077 | old_cluster[j++] = get_l2_entry(s, l2_slice, l2_index + i); |
Kevin Wolf | aaa4d20 | 2016-06-01 15:21:05 +0200 | [diff] [blame] | 1078 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1079 | |
Alberto Garcia | 3a75a87 | 2020-01-13 17:11:46 +0100 | [diff] [blame] | 1080 | /* The offset must fit in the offset field of the L2 table entry */ |
| 1081 | assert((offset & L2E_OFFSET_MASK) == offset); |
| 1082 | |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 1083 | set_l2_entry(s, l2_slice, l2_index + i, offset | QCOW_OFLAG_COPIED); |
Alberto Garcia | aca00cd | 2020-07-10 18:13:07 +0200 | [diff] [blame] | 1084 | |
| 1085 | /* Update bitmap with the subclusters that were just written */ |
Alberto Garcia | 40dee94 | 2020-07-10 18:13:12 +0200 | [diff] [blame] | 1086 | if (has_subclusters(s) && !m->prealloc) { |
Alberto Garcia | aca00cd | 2020-07-10 18:13:07 +0200 | [diff] [blame] | 1087 | uint64_t l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index + i); |
| 1088 | unsigned written_from = m->cow_start.offset; |
Alberto Garcia | 3441ad4 | 2020-10-07 18:13:23 +0200 | [diff] [blame] | 1089 | unsigned written_to = m->cow_end.offset + m->cow_end.nb_bytes; |
Alberto Garcia | aca00cd | 2020-07-10 18:13:07 +0200 | [diff] [blame] | 1090 | int first_sc, last_sc; |
| 1091 | /* Narrow written_from and written_to down to the current cluster */ |
| 1092 | written_from = MAX(written_from, i << s->cluster_bits); |
| 1093 | written_to = MIN(written_to, (i + 1) << s->cluster_bits); |
| 1094 | assert(written_from < written_to); |
| 1095 | first_sc = offset_to_sc_index(s, written_from); |
| 1096 | last_sc = offset_to_sc_index(s, written_to - 1); |
| 1097 | l2_bitmap |= QCOW_OFLAG_SUB_ALLOC_RANGE(first_sc, last_sc + 1); |
| 1098 | l2_bitmap &= ~QCOW_OFLAG_SUB_ZERO_RANGE(first_sc, last_sc + 1); |
| 1099 | set_l2_bitmap(s, l2_slice, l2_index + i, l2_bitmap); |
| 1100 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1101 | } |
| 1102 | |
Kevin Wolf | 9f8e668 | 2010-09-17 17:02:09 +0200 | [diff] [blame] | 1103 | |
Alberto Garcia | a002c0b | 2018-02-05 16:33:21 +0200 | [diff] [blame] | 1104 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1105 | |
Kevin Wolf | 7ec5e6a | 2010-09-01 12:40:52 +0200 | [diff] [blame] | 1106 | /* |
| 1107 | * If this was a COW, we need to decrease the refcount of the old cluster. |
Kevin Wolf | 6cfcb9b | 2013-06-19 13:44:18 +0200 | [diff] [blame] | 1108 | * |
| 1109 | * Don't discard clusters that reach a refcount of 0 (e.g. compressed |
| 1110 | * clusters), the next write will reuse them anyway. |
Kevin Wolf | 7ec5e6a | 2010-09-01 12:40:52 +0200 | [diff] [blame] | 1111 | */ |
Max Reitz | 564a6b6 | 2017-05-04 01:11:18 +0200 | [diff] [blame] | 1112 | if (!m->keep_old_clusters && j != 0) { |
Kevin Wolf | 7ec5e6a | 2010-09-01 12:40:52 +0200 | [diff] [blame] | 1113 | for (i = 0; i < j; i++) { |
Alberto Garcia | 3fec237 | 2020-09-08 16:08:28 +0200 | [diff] [blame] | 1114 | qcow2_free_any_cluster(bs, old_cluster[i], QCOW2_DISCARD_NEVER); |
Kevin Wolf | 7ec5e6a | 2010-09-01 12:40:52 +0200 | [diff] [blame] | 1115 | } |
| 1116 | } |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1117 | |
| 1118 | ret = 0; |
| 1119 | err: |
Anthony Liguori | 7267c09 | 2011-08-20 22:09:37 -0500 | [diff] [blame] | 1120 | g_free(old_cluster); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1121 | return ret; |
| 1122 | } |
| 1123 | |
Kevin Wolf | 8b24cd1 | 2018-06-28 17:05:45 +0200 | [diff] [blame] | 1124 | /** |
| 1125 | * Frees the allocated clusters because the request failed and they won't |
| 1126 | * actually be linked. |
| 1127 | */ |
Paolo Bonzini | a39bae4 | 2023-03-09 09:44:55 +0100 | [diff] [blame] | 1128 | void coroutine_fn qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m) |
Kevin Wolf | 8b24cd1 | 2018-06-28 17:05:45 +0200 | [diff] [blame] | 1129 | { |
| 1130 | BDRVQcow2State *s = bs->opaque; |
Max Reitz | 3ede935 | 2020-02-25 15:31:28 +0100 | [diff] [blame] | 1131 | if (!has_data_file(bs) && !m->keep_old_clusters) { |
Kevin Wolf | c3b6658 | 2020-02-11 10:48:59 +0100 | [diff] [blame] | 1132 | qcow2_free_clusters(bs, m->alloc_offset, |
| 1133 | m->nb_clusters << s->cluster_bits, |
| 1134 | QCOW2_DISCARD_NEVER); |
| 1135 | } |
Kevin Wolf | 8b24cd1 | 2018-06-28 17:05:45 +0200 | [diff] [blame] | 1136 | } |
| 1137 | |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1138 | /* |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1139 | * For a given write request, create a new QCowL2Meta structure, add |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1140 | * it to @m and the BDRVQcow2State.cluster_allocs list. If the write |
| 1141 | * request does not need copy-on-write or changes to the L2 metadata |
| 1142 | * then this function does nothing. |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1143 | * |
| 1144 | * @host_cluster_offset points to the beginning of the first cluster. |
| 1145 | * |
| 1146 | * @guest_offset and @bytes indicate the offset and length of the |
| 1147 | * request. |
| 1148 | * |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1149 | * @l2_slice contains the L2 entries of all clusters involved in this |
| 1150 | * write request. |
| 1151 | * |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1152 | * If @keep_old is true it means that the clusters were already |
| 1153 | * allocated and will be overwritten. If false then the clusters are |
| 1154 | * new and we have to decrease the reference count of the old ones. |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1155 | * |
| 1156 | * Returns 0 on success, -errno on failure. |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1157 | */ |
Paolo Bonzini | a39bae4 | 2023-03-09 09:44:55 +0100 | [diff] [blame] | 1158 | static int coroutine_fn calculate_l2_meta(BlockDriverState *bs, |
| 1159 | uint64_t host_cluster_offset, |
| 1160 | uint64_t guest_offset, unsigned bytes, |
| 1161 | uint64_t *l2_slice, QCowL2Meta **m, |
| 1162 | bool keep_old) |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1163 | { |
| 1164 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1165 | int sc_index, l2_index = offset_to_l2_slice_index(s, guest_offset); |
| 1166 | uint64_t l2_entry, l2_bitmap; |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1167 | unsigned cow_start_from, cow_end_to; |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1168 | unsigned cow_start_to = offset_into_cluster(s, guest_offset); |
| 1169 | unsigned cow_end_from = cow_start_to + bytes; |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1170 | unsigned nb_clusters = size_to_clusters(s, cow_end_from); |
| 1171 | QCowL2Meta *old_m = *m; |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1172 | QCow2SubclusterType type; |
| 1173 | int i; |
| 1174 | bool skip_cow = keep_old; |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1175 | |
| 1176 | assert(nb_clusters <= s->l2_slice_size - l2_index); |
| 1177 | |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1178 | /* Check the type of all affected subclusters */ |
| 1179 | for (i = 0; i < nb_clusters; i++) { |
| 1180 | l2_entry = get_l2_entry(s, l2_slice, l2_index + i); |
| 1181 | l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index + i); |
| 1182 | if (skip_cow) { |
| 1183 | unsigned write_from = MAX(cow_start_to, i << s->cluster_bits); |
| 1184 | unsigned write_to = MIN(cow_end_from, (i + 1) << s->cluster_bits); |
| 1185 | int first_sc = offset_to_sc_index(s, write_from); |
| 1186 | int last_sc = offset_to_sc_index(s, write_to - 1); |
| 1187 | int cnt = qcow2_get_subcluster_range_type(bs, l2_entry, l2_bitmap, |
| 1188 | first_sc, &type); |
| 1189 | /* Is any of the subclusters of type != QCOW2_SUBCLUSTER_NORMAL ? */ |
| 1190 | if (type != QCOW2_SUBCLUSTER_NORMAL || first_sc + cnt <= last_sc) { |
| 1191 | skip_cow = false; |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1192 | } |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1193 | } else { |
| 1194 | /* If we can't skip the cow we can still look for invalid entries */ |
| 1195 | type = qcow2_get_subcluster_type(bs, l2_entry, l2_bitmap, 0); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1196 | } |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1197 | if (type == QCOW2_SUBCLUSTER_INVALID) { |
| 1198 | int l1_index = offset_to_l1_index(s, guest_offset); |
| 1199 | uint64_t l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK; |
| 1200 | qcow2_signal_corruption(bs, true, -1, -1, "Invalid cluster " |
| 1201 | "entry found (L2 offset: %#" PRIx64 |
| 1202 | ", L2 index: %#x)", |
| 1203 | l2_offset, l2_index + i); |
| 1204 | return -EIO; |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1205 | } |
| 1206 | } |
| 1207 | |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1208 | if (skip_cow) { |
| 1209 | return 0; |
| 1210 | } |
| 1211 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1212 | /* Get the L2 entry of the first cluster */ |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 1213 | l2_entry = get_l2_entry(s, l2_slice, l2_index); |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1214 | l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index); |
| 1215 | sc_index = offset_to_sc_index(s, guest_offset); |
| 1216 | type = qcow2_get_subcluster_type(bs, l2_entry, l2_bitmap, sc_index); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1217 | |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1218 | if (!keep_old) { |
| 1219 | switch (type) { |
| 1220 | case QCOW2_SUBCLUSTER_COMPRESSED: |
| 1221 | cow_start_from = 0; |
| 1222 | break; |
| 1223 | case QCOW2_SUBCLUSTER_NORMAL: |
| 1224 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 1225 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: |
| 1226 | if (has_subclusters(s)) { |
| 1227 | /* Skip all leading zero and unallocated subclusters */ |
| 1228 | uint32_t alloc_bitmap = l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC; |
| 1229 | cow_start_from = |
| 1230 | MIN(sc_index, ctz32(alloc_bitmap)) << s->subcluster_bits; |
| 1231 | } else { |
| 1232 | cow_start_from = 0; |
| 1233 | } |
| 1234 | break; |
| 1235 | case QCOW2_SUBCLUSTER_ZERO_PLAIN: |
| 1236 | case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: |
| 1237 | cow_start_from = sc_index << s->subcluster_bits; |
| 1238 | break; |
| 1239 | default: |
| 1240 | g_assert_not_reached(); |
| 1241 | } |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1242 | } else { |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1243 | switch (type) { |
| 1244 | case QCOW2_SUBCLUSTER_NORMAL: |
| 1245 | cow_start_from = cow_start_to; |
| 1246 | break; |
| 1247 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 1248 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: |
| 1249 | cow_start_from = sc_index << s->subcluster_bits; |
| 1250 | break; |
| 1251 | default: |
| 1252 | g_assert_not_reached(); |
| 1253 | } |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1254 | } |
| 1255 | |
| 1256 | /* Get the L2 entry of the last cluster */ |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1257 | l2_index += nb_clusters - 1; |
| 1258 | l2_entry = get_l2_entry(s, l2_slice, l2_index); |
| 1259 | l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index); |
| 1260 | sc_index = offset_to_sc_index(s, guest_offset + bytes - 1); |
| 1261 | type = qcow2_get_subcluster_type(bs, l2_entry, l2_bitmap, sc_index); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1262 | |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1263 | if (!keep_old) { |
| 1264 | switch (type) { |
| 1265 | case QCOW2_SUBCLUSTER_COMPRESSED: |
| 1266 | cow_end_to = ROUND_UP(cow_end_from, s->cluster_size); |
| 1267 | break; |
| 1268 | case QCOW2_SUBCLUSTER_NORMAL: |
| 1269 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 1270 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: |
| 1271 | cow_end_to = ROUND_UP(cow_end_from, s->cluster_size); |
| 1272 | if (has_subclusters(s)) { |
| 1273 | /* Skip all trailing zero and unallocated subclusters */ |
| 1274 | uint32_t alloc_bitmap = l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC; |
| 1275 | cow_end_to -= |
| 1276 | MIN(s->subclusters_per_cluster - sc_index - 1, |
| 1277 | clz32(alloc_bitmap)) << s->subcluster_bits; |
| 1278 | } |
| 1279 | break; |
| 1280 | case QCOW2_SUBCLUSTER_ZERO_PLAIN: |
| 1281 | case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: |
| 1282 | cow_end_to = ROUND_UP(cow_end_from, s->subcluster_size); |
| 1283 | break; |
| 1284 | default: |
| 1285 | g_assert_not_reached(); |
| 1286 | } |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1287 | } else { |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1288 | switch (type) { |
| 1289 | case QCOW2_SUBCLUSTER_NORMAL: |
| 1290 | cow_end_to = cow_end_from; |
| 1291 | break; |
| 1292 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 1293 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: |
| 1294 | cow_end_to = ROUND_UP(cow_end_from, s->subcluster_size); |
| 1295 | break; |
| 1296 | default: |
| 1297 | g_assert_not_reached(); |
| 1298 | } |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1299 | } |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1300 | |
| 1301 | *m = g_malloc0(sizeof(**m)); |
| 1302 | **m = (QCowL2Meta) { |
| 1303 | .next = old_m, |
| 1304 | |
| 1305 | .alloc_offset = host_cluster_offset, |
| 1306 | .offset = start_of_cluster(s, guest_offset), |
| 1307 | .nb_clusters = nb_clusters, |
| 1308 | |
| 1309 | .keep_old_clusters = keep_old, |
| 1310 | |
| 1311 | .cow_start = { |
| 1312 | .offset = cow_start_from, |
| 1313 | .nb_bytes = cow_start_to - cow_start_from, |
| 1314 | }, |
| 1315 | .cow_end = { |
| 1316 | .offset = cow_end_from, |
| 1317 | .nb_bytes = cow_end_to - cow_end_from, |
| 1318 | }, |
| 1319 | }; |
| 1320 | |
| 1321 | qemu_co_queue_init(&(*m)->dependent_requests); |
| 1322 | QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1323 | |
| 1324 | return 0; |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1325 | } |
| 1326 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1327 | /* |
| 1328 | * Returns true if writing to the cluster pointed to by @l2_entry |
| 1329 | * requires a new allocation (that is, if the cluster is unallocated |
| 1330 | * or has refcount > 1 and therefore cannot be written in-place). |
| 1331 | */ |
| 1332 | static bool cluster_needs_new_alloc(BlockDriverState *bs, uint64_t l2_entry) |
Alberto Garcia | c1587d8 | 2020-07-10 18:12:46 +0200 | [diff] [blame] | 1333 | { |
| 1334 | switch (qcow2_get_cluster_type(bs, l2_entry)) { |
| 1335 | case QCOW2_CLUSTER_NORMAL: |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1336 | case QCOW2_CLUSTER_ZERO_ALLOC: |
Alberto Garcia | c1587d8 | 2020-07-10 18:12:46 +0200 | [diff] [blame] | 1337 | if (l2_entry & QCOW_OFLAG_COPIED) { |
| 1338 | return false; |
| 1339 | } |
Thomas Huth | b9be6fa | 2020-09-08 09:00:28 +0200 | [diff] [blame] | 1340 | /* fallthrough */ |
Alberto Garcia | c1587d8 | 2020-07-10 18:12:46 +0200 | [diff] [blame] | 1341 | case QCOW2_CLUSTER_UNALLOCATED: |
| 1342 | case QCOW2_CLUSTER_COMPRESSED: |
| 1343 | case QCOW2_CLUSTER_ZERO_PLAIN: |
Alberto Garcia | c1587d8 | 2020-07-10 18:12:46 +0200 | [diff] [blame] | 1344 | return true; |
| 1345 | default: |
| 1346 | abort(); |
| 1347 | } |
| 1348 | } |
| 1349 | |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1350 | /* |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1351 | * Returns the number of contiguous clusters that can be written to |
| 1352 | * using one single write request, starting from @l2_index. |
| 1353 | * At most @nb_clusters are checked. |
| 1354 | * |
| 1355 | * If @new_alloc is true this counts clusters that are either |
| 1356 | * unallocated, or allocated but with refcount > 1 (so they need to be |
| 1357 | * newly allocated and COWed). |
| 1358 | * |
| 1359 | * If @new_alloc is false this counts clusters that are already |
| 1360 | * allocated and can be overwritten in-place (this includes clusters |
| 1361 | * of type QCOW2_CLUSTER_ZERO_ALLOC). |
Kevin Wolf | bf319ec | 2012-03-02 19:27:53 +0100 | [diff] [blame] | 1362 | */ |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1363 | static int count_single_write_clusters(BlockDriverState *bs, int nb_clusters, |
| 1364 | uint64_t *l2_slice, int l2_index, |
| 1365 | bool new_alloc) |
Kevin Wolf | bf319ec | 2012-03-02 19:27:53 +0100 | [diff] [blame] | 1366 | { |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1367 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 1368 | uint64_t l2_entry = get_l2_entry(s, l2_slice, l2_index); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1369 | uint64_t expected_offset = l2_entry & L2E_OFFSET_MASK; |
Kevin Wolf | 143550a | 2012-03-27 13:17:22 +0200 | [diff] [blame] | 1370 | int i; |
Kevin Wolf | bf319ec | 2012-03-02 19:27:53 +0100 | [diff] [blame] | 1371 | |
Kevin Wolf | 143550a | 2012-03-27 13:17:22 +0200 | [diff] [blame] | 1372 | for (i = 0; i < nb_clusters; i++) { |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 1373 | l2_entry = get_l2_entry(s, l2_slice, l2_index + i); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1374 | if (cluster_needs_new_alloc(bs, l2_entry) != new_alloc) { |
Kevin Wolf | bf319ec | 2012-03-02 19:27:53 +0100 | [diff] [blame] | 1375 | break; |
| 1376 | } |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1377 | if (!new_alloc) { |
| 1378 | if (expected_offset != (l2_entry & L2E_OFFSET_MASK)) { |
| 1379 | break; |
| 1380 | } |
| 1381 | expected_offset += s->cluster_size; |
| 1382 | } |
Kevin Wolf | bf319ec | 2012-03-02 19:27:53 +0100 | [diff] [blame] | 1383 | } |
| 1384 | |
| 1385 | assert(i <= nb_clusters); |
| 1386 | return i; |
| 1387 | } |
| 1388 | |
| 1389 | /* |
Kevin Wolf | 226c3c2 | 2012-12-07 18:08:49 +0100 | [diff] [blame] | 1390 | * Check if there already is an AIO write request in flight which allocates |
| 1391 | * the same cluster. In this case we need to wait until the previous |
| 1392 | * request has completed and updated the L2 table accordingly. |
Kevin Wolf | 65eb2e3 | 2013-03-26 17:49:58 +0100 | [diff] [blame] | 1393 | * |
| 1394 | * Returns: |
| 1395 | * 0 if there was no dependency. *cur_bytes indicates the number of |
| 1396 | * bytes from guest_offset that can be read before the next |
| 1397 | * dependency must be processed (or the request is complete) |
| 1398 | * |
| 1399 | * -EAGAIN if we had to wait for another request, previously gathered |
| 1400 | * information on cluster allocation may be invalid now. The caller |
| 1401 | * must start over anyway, so consider *cur_bytes undefined. |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1402 | */ |
Paolo Bonzini | 050ed2e | 2022-09-22 10:49:12 +0200 | [diff] [blame] | 1403 | static int coroutine_fn handle_dependencies(BlockDriverState *bs, |
| 1404 | uint64_t guest_offset, |
| 1405 | uint64_t *cur_bytes, QCowL2Meta **m) |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1406 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1407 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1408 | QCowL2Meta *old_alloc; |
Kevin Wolf | 65eb2e3 | 2013-03-26 17:49:58 +0100 | [diff] [blame] | 1409 | uint64_t bytes = *cur_bytes; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1410 | |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1411 | QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) { |
| 1412 | |
Kevin Wolf | 65eb2e3 | 2013-03-26 17:49:58 +0100 | [diff] [blame] | 1413 | uint64_t start = guest_offset; |
| 1414 | uint64_t end = start + bytes; |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1415 | uint64_t old_start = start_of_cluster(s, l2meta_cow_start(old_alloc)); |
| 1416 | uint64_t old_end = ROUND_UP(l2meta_cow_end(old_alloc), s->cluster_size); |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1417 | |
Kevin Wolf | d9d74f4 | 2013-03-26 17:49:57 +0100 | [diff] [blame] | 1418 | if (end <= old_start || start >= old_end) { |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1419 | /* No intersection */ |
Vladimir Sementsov-Ogievskiy | 6d207d3 | 2021-08-24 13:15:16 +0300 | [diff] [blame] | 1420 | continue; |
| 1421 | } |
| 1422 | |
Vladimir Sementsov-Ogievskiy | ff812c5 | 2021-08-24 13:15:17 +0300 | [diff] [blame] | 1423 | if (old_alloc->keep_old_clusters && |
| 1424 | (end <= l2meta_cow_start(old_alloc) || |
| 1425 | start >= l2meta_cow_end(old_alloc))) |
| 1426 | { |
| 1427 | /* |
| 1428 | * Clusters intersect but COW areas don't. And cluster itself is |
| 1429 | * already allocated. So, there is no actual conflict. |
| 1430 | */ |
| 1431 | continue; |
| 1432 | } |
| 1433 | |
Vladimir Sementsov-Ogievskiy | 6d207d3 | 2021-08-24 13:15:16 +0300 | [diff] [blame] | 1434 | /* Conflict */ |
| 1435 | |
| 1436 | if (start < old_start) { |
| 1437 | /* Stop at the start of a running allocation */ |
| 1438 | bytes = old_start - start; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1439 | } else { |
Vladimir Sementsov-Ogievskiy | 6d207d3 | 2021-08-24 13:15:16 +0300 | [diff] [blame] | 1440 | bytes = 0; |
| 1441 | } |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1442 | |
Vladimir Sementsov-Ogievskiy | 6d207d3 | 2021-08-24 13:15:16 +0300 | [diff] [blame] | 1443 | /* |
| 1444 | * Stop if an l2meta already exists. After yielding, it wouldn't |
| 1445 | * be valid any more, so we'd have to clean up the old L2Metas |
| 1446 | * and deal with requests depending on them before starting to |
| 1447 | * gather new ones. Not worth the trouble. |
| 1448 | */ |
| 1449 | if (bytes == 0 && *m) { |
| 1450 | *cur_bytes = 0; |
| 1451 | return 0; |
| 1452 | } |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1453 | |
Vladimir Sementsov-Ogievskiy | 6d207d3 | 2021-08-24 13:15:16 +0300 | [diff] [blame] | 1454 | if (bytes == 0) { |
| 1455 | /* |
| 1456 | * Wait for the dependency to complete. We need to recheck |
| 1457 | * the free/allocated clusters when we continue. |
| 1458 | */ |
| 1459 | qemu_co_queue_wait(&old_alloc->dependent_requests, &s->lock); |
| 1460 | return -EAGAIN; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1461 | } |
| 1462 | } |
| 1463 | |
Kevin Wolf | 65eb2e3 | 2013-03-26 17:49:58 +0100 | [diff] [blame] | 1464 | /* Make sure that existing clusters and new allocations are only used up to |
| 1465 | * the next dependency if we shortened the request above */ |
| 1466 | *cur_bytes = bytes; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1467 | |
Kevin Wolf | 226c3c2 | 2012-12-07 18:08:49 +0100 | [diff] [blame] | 1468 | return 0; |
| 1469 | } |
| 1470 | |
| 1471 | /* |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1472 | * Checks how many already allocated clusters that don't require a new |
| 1473 | * allocation there are at the given guest_offset (up to *bytes). |
| 1474 | * If *host_offset is not INV_OFFSET, only physically contiguous clusters |
| 1475 | * beginning at this host offset are counted. |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1476 | * |
Kevin Wolf | 411d62b | 2013-03-26 17:50:09 +0100 | [diff] [blame] | 1477 | * Note that guest_offset may not be cluster aligned. In this case, the |
| 1478 | * returned *host_offset points to exact byte referenced by guest_offset and |
| 1479 | * therefore isn't cluster aligned as well. |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1480 | * |
| 1481 | * Returns: |
| 1482 | * 0: if no allocated clusters are available at the given offset. |
| 1483 | * *bytes is normally unchanged. It is set to 0 if the cluster |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1484 | * is allocated and can be overwritten in-place but doesn't have |
| 1485 | * the right physical offset. |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1486 | * |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1487 | * 1: if allocated clusters that can be overwritten in place are |
| 1488 | * available at the requested offset. *bytes may have decreased |
| 1489 | * and describes the length of the area that can be written to. |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1490 | * |
| 1491 | * -errno: in error cases |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1492 | */ |
Paolo Bonzini | a1b4ecf | 2022-10-13 14:36:59 +0200 | [diff] [blame] | 1493 | static int coroutine_fn handle_copied(BlockDriverState *bs, |
| 1494 | uint64_t guest_offset, uint64_t *host_offset, uint64_t *bytes, |
| 1495 | QCowL2Meta **m) |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1496 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1497 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1498 | int l2_index; |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1499 | uint64_t l2_entry, cluster_offset; |
Alberto Garcia | cde9176 | 2018-02-05 16:33:22 +0200 | [diff] [blame] | 1500 | uint64_t *l2_slice; |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 1501 | uint64_t nb_clusters; |
Kevin Wolf | c53ede9 | 2013-03-26 17:50:07 +0100 | [diff] [blame] | 1502 | unsigned int keep_clusters; |
Alberto Garcia | a3f1afb | 2015-05-11 15:54:58 +0300 | [diff] [blame] | 1503 | int ret; |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1504 | |
| 1505 | trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset, |
| 1506 | *bytes); |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1507 | |
Kevin Wolf | c6d619c | 2019-01-18 14:40:36 +0100 | [diff] [blame] | 1508 | assert(*host_offset == INV_OFFSET || offset_into_cluster(s, guest_offset) |
| 1509 | == offset_into_cluster(s, *host_offset)); |
Kevin Wolf | 411d62b | 2013-03-26 17:50:09 +0100 | [diff] [blame] | 1510 | |
Kevin Wolf | acb0467 | 2013-03-26 17:50:06 +0100 | [diff] [blame] | 1511 | /* |
Alberto Garcia | cde9176 | 2018-02-05 16:33:22 +0200 | [diff] [blame] | 1512 | * Calculate the number of clusters to look for. We stop at L2 slice |
Kevin Wolf | acb0467 | 2013-03-26 17:50:06 +0100 | [diff] [blame] | 1513 | * boundaries to keep things simple. |
| 1514 | */ |
| 1515 | nb_clusters = |
| 1516 | size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes); |
| 1517 | |
Alberto Garcia | cde9176 | 2018-02-05 16:33:22 +0200 | [diff] [blame] | 1518 | l2_index = offset_to_l2_slice_index(s, guest_offset); |
| 1519 | nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1520 | /* Limit total byte count to BDRV_REQUEST_MAX_BYTES */ |
| 1521 | nb_clusters = MIN(nb_clusters, BDRV_REQUEST_MAX_BYTES >> s->cluster_bits); |
Kevin Wolf | acb0467 | 2013-03-26 17:50:06 +0100 | [diff] [blame] | 1522 | |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1523 | /* Find L2 entry for the first involved cluster */ |
Alberto Garcia | cde9176 | 2018-02-05 16:33:22 +0200 | [diff] [blame] | 1524 | ret = get_cluster_table(bs, guest_offset, &l2_slice, &l2_index); |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1525 | if (ret < 0) { |
| 1526 | return ret; |
| 1527 | } |
| 1528 | |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 1529 | l2_entry = get_l2_entry(s, l2_slice, l2_index); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1530 | cluster_offset = l2_entry & L2E_OFFSET_MASK; |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1531 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1532 | if (!cluster_needs_new_alloc(bs, l2_entry)) { |
| 1533 | if (offset_into_cluster(s, cluster_offset)) { |
| 1534 | qcow2_signal_corruption(bs, true, -1, -1, "%s cluster offset " |
| 1535 | "%#" PRIx64 " unaligned (guest offset: %#" |
| 1536 | PRIx64 ")", l2_entry & QCOW_OFLAG_ZERO ? |
| 1537 | "Preallocated zero" : "Data", |
| 1538 | cluster_offset, guest_offset); |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 1539 | ret = -EIO; |
| 1540 | goto out; |
| 1541 | } |
| 1542 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1543 | /* If a specific host_offset is required, check it */ |
| 1544 | if (*host_offset != INV_OFFSET && cluster_offset != *host_offset) { |
Kevin Wolf | e62daaf | 2013-03-26 17:50:08 +0100 | [diff] [blame] | 1545 | *bytes = 0; |
| 1546 | ret = 0; |
| 1547 | goto out; |
| 1548 | } |
| 1549 | |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1550 | /* We keep all QCOW_OFLAG_COPIED clusters */ |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1551 | keep_clusters = count_single_write_clusters(bs, nb_clusters, l2_slice, |
| 1552 | l2_index, false); |
Kevin Wolf | c53ede9 | 2013-03-26 17:50:07 +0100 | [diff] [blame] | 1553 | assert(keep_clusters <= nb_clusters); |
| 1554 | |
| 1555 | *bytes = MIN(*bytes, |
| 1556 | keep_clusters * s->cluster_size |
| 1557 | - offset_into_cluster(s, guest_offset)); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1558 | assert(*bytes != 0); |
| 1559 | |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1560 | ret = calculate_l2_meta(bs, cluster_offset, guest_offset, |
| 1561 | *bytes, l2_slice, m, true); |
| 1562 | if (ret < 0) { |
| 1563 | goto out; |
| 1564 | } |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1565 | |
| 1566 | ret = 1; |
| 1567 | } else { |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1568 | ret = 0; |
| 1569 | } |
| 1570 | |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1571 | /* Cleanup */ |
Kevin Wolf | e62daaf | 2013-03-26 17:50:08 +0100 | [diff] [blame] | 1572 | out: |
Alberto Garcia | cde9176 | 2018-02-05 16:33:22 +0200 | [diff] [blame] | 1573 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1574 | |
Kevin Wolf | e62daaf | 2013-03-26 17:50:08 +0100 | [diff] [blame] | 1575 | /* Only return a host offset if we actually made progress. Otherwise we |
| 1576 | * would make requirements for handle_alloc() that it can't fulfill */ |
Max Reitz | a97c67e | 2014-09-05 16:07:18 +0200 | [diff] [blame] | 1577 | if (ret > 0) { |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1578 | *host_offset = cluster_offset + offset_into_cluster(s, guest_offset); |
Kevin Wolf | e62daaf | 2013-03-26 17:50:08 +0100 | [diff] [blame] | 1579 | } |
| 1580 | |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1581 | return ret; |
| 1582 | } |
| 1583 | |
| 1584 | /* |
Kevin Wolf | 226c3c2 | 2012-12-07 18:08:49 +0100 | [diff] [blame] | 1585 | * Allocates new clusters for the given guest_offset. |
| 1586 | * |
| 1587 | * At most *nb_clusters are allocated, and on return *nb_clusters is updated to |
| 1588 | * contain the number of clusters that have been allocated and are contiguous |
| 1589 | * in the image file. |
| 1590 | * |
Kevin Wolf | c6d619c | 2019-01-18 14:40:36 +0100 | [diff] [blame] | 1591 | * If *host_offset is not INV_OFFSET, it specifies the offset in the image file |
| 1592 | * at which the new clusters must start. *nb_clusters can be 0 on return in |
| 1593 | * this case if the cluster at host_offset is already in use. If *host_offset |
| 1594 | * is INV_OFFSET, the clusters can be allocated anywhere in the image file. |
Kevin Wolf | 226c3c2 | 2012-12-07 18:08:49 +0100 | [diff] [blame] | 1595 | * |
| 1596 | * *host_offset is updated to contain the offset into the image file at which |
| 1597 | * the first allocated cluster starts. |
| 1598 | * |
| 1599 | * Return 0 on success and -errno in error cases. -EAGAIN means that the |
| 1600 | * function has been waiting for another request and the allocation must be |
| 1601 | * restarted, but the whole request should not be failed. |
| 1602 | */ |
Paolo Bonzini | a39bae4 | 2023-03-09 09:44:55 +0100 | [diff] [blame] | 1603 | static int coroutine_fn do_alloc_cluster_offset(BlockDriverState *bs, |
| 1604 | uint64_t guest_offset, |
| 1605 | uint64_t *host_offset, |
| 1606 | uint64_t *nb_clusters) |
Kevin Wolf | 226c3c2 | 2012-12-07 18:08:49 +0100 | [diff] [blame] | 1607 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1608 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 226c3c2 | 2012-12-07 18:08:49 +0100 | [diff] [blame] | 1609 | |
| 1610 | trace_qcow2_do_alloc_clusters_offset(qemu_coroutine_self(), guest_offset, |
| 1611 | *host_offset, *nb_clusters); |
| 1612 | |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 1613 | if (has_data_file(bs)) { |
| 1614 | assert(*host_offset == INV_OFFSET || |
| 1615 | *host_offset == start_of_cluster(s, guest_offset)); |
| 1616 | *host_offset = start_of_cluster(s, guest_offset); |
| 1617 | return 0; |
| 1618 | } |
| 1619 | |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1620 | /* Allocate new clusters */ |
| 1621 | trace_qcow2_cluster_alloc_phys(qemu_coroutine_self()); |
Kevin Wolf | c6d619c | 2019-01-18 14:40:36 +0100 | [diff] [blame] | 1622 | if (*host_offset == INV_OFFSET) { |
Kevin Wolf | df02179 | 2012-05-24 12:56:32 +0200 | [diff] [blame] | 1623 | int64_t cluster_offset = |
| 1624 | qcow2_alloc_clusters(bs, *nb_clusters * s->cluster_size); |
| 1625 | if (cluster_offset < 0) { |
| 1626 | return cluster_offset; |
| 1627 | } |
| 1628 | *host_offset = cluster_offset; |
| 1629 | return 0; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1630 | } else { |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 1631 | int64_t ret = qcow2_alloc_clusters_at(bs, *host_offset, *nb_clusters); |
Kevin Wolf | df02179 | 2012-05-24 12:56:32 +0200 | [diff] [blame] | 1632 | if (ret < 0) { |
| 1633 | return ret; |
| 1634 | } |
| 1635 | *nb_clusters = ret; |
| 1636 | return 0; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1637 | } |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1638 | } |
| 1639 | |
| 1640 | /* |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1641 | * Allocates new clusters for an area that is either still unallocated or |
| 1642 | * cannot be overwritten in-place. If *host_offset is not INV_OFFSET, |
| 1643 | * clusters are only allocated if the new allocation can match the specified |
| 1644 | * host offset. |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1645 | * |
Kevin Wolf | 411d62b | 2013-03-26 17:50:09 +0100 | [diff] [blame] | 1646 | * Note that guest_offset may not be cluster aligned. In this case, the |
| 1647 | * returned *host_offset points to exact byte referenced by guest_offset and |
| 1648 | * therefore isn't cluster aligned as well. |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1649 | * |
| 1650 | * Returns: |
| 1651 | * 0: if no clusters could be allocated. *bytes is set to 0, |
| 1652 | * *host_offset is left unchanged. |
| 1653 | * |
| 1654 | * 1: if new clusters were allocated. *bytes may be decreased if the |
| 1655 | * new allocation doesn't cover all of the requested area. |
| 1656 | * *host_offset is updated to contain the host offset of the first |
| 1657 | * newly allocated cluster. |
| 1658 | * |
| 1659 | * -errno: in error cases |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1660 | */ |
Paolo Bonzini | a1b4ecf | 2022-10-13 14:36:59 +0200 | [diff] [blame] | 1661 | static int coroutine_fn handle_alloc(BlockDriverState *bs, |
| 1662 | uint64_t guest_offset, uint64_t *host_offset, uint64_t *bytes, |
| 1663 | QCowL2Meta **m) |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1664 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1665 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1666 | int l2_index; |
Alberto Garcia | 6d99a34 | 2018-02-05 16:33:23 +0200 | [diff] [blame] | 1667 | uint64_t *l2_slice; |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 1668 | uint64_t nb_clusters; |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1669 | int ret; |
| 1670 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1671 | uint64_t alloc_cluster_offset; |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1672 | |
| 1673 | trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset, |
| 1674 | *bytes); |
| 1675 | assert(*bytes > 0); |
| 1676 | |
Kevin Wolf | f5bc635 | 2013-03-26 17:50:01 +0100 | [diff] [blame] | 1677 | /* |
Alberto Garcia | 6d99a34 | 2018-02-05 16:33:23 +0200 | [diff] [blame] | 1678 | * Calculate the number of clusters to look for. We stop at L2 slice |
Kevin Wolf | f5bc635 | 2013-03-26 17:50:01 +0100 | [diff] [blame] | 1679 | * boundaries to keep things simple. |
| 1680 | */ |
Kevin Wolf | c37f4cd | 2013-03-26 17:50:03 +0100 | [diff] [blame] | 1681 | nb_clusters = |
| 1682 | size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes); |
| 1683 | |
Alberto Garcia | 6d99a34 | 2018-02-05 16:33:23 +0200 | [diff] [blame] | 1684 | l2_index = offset_to_l2_slice_index(s, guest_offset); |
| 1685 | nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index); |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1686 | /* Limit total allocation byte count to BDRV_REQUEST_MAX_BYTES */ |
| 1687 | nb_clusters = MIN(nb_clusters, BDRV_REQUEST_MAX_BYTES >> s->cluster_bits); |
Max Reitz | d1b9d19 | 2019-10-10 12:08:57 +0200 | [diff] [blame] | 1688 | |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1689 | /* Find L2 entry for the first involved cluster */ |
Alberto Garcia | 6d99a34 | 2018-02-05 16:33:23 +0200 | [diff] [blame] | 1690 | ret = get_cluster_table(bs, guest_offset, &l2_slice, &l2_index); |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1691 | if (ret < 0) { |
| 1692 | return ret; |
| 1693 | } |
| 1694 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1695 | nb_clusters = count_single_write_clusters(bs, nb_clusters, |
| 1696 | l2_slice, l2_index, true); |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1697 | |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1698 | /* This function is only called when there were no non-COW clusters, so if |
| 1699 | * we can't find any unallocated or COW clusters either, something is |
| 1700 | * wrong with our code. */ |
| 1701 | assert(nb_clusters > 0); |
| 1702 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1703 | /* Allocate at a given offset in the image file */ |
| 1704 | alloc_cluster_offset = *host_offset == INV_OFFSET ? INV_OFFSET : |
| 1705 | start_of_cluster(s, *host_offset); |
| 1706 | ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset, |
| 1707 | &nb_clusters); |
| 1708 | if (ret < 0) { |
| 1709 | goto out; |
Max Reitz | 564a6b6 | 2017-05-04 01:11:18 +0200 | [diff] [blame] | 1710 | } |
| 1711 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1712 | /* Can't extend contiguous allocation */ |
| 1713 | if (nb_clusters == 0) { |
| 1714 | *bytes = 0; |
| 1715 | ret = 0; |
| 1716 | goto out; |
Max Reitz | ff52aab | 2014-08-07 22:47:53 +0200 | [diff] [blame] | 1717 | } |
| 1718 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1719 | assert(alloc_cluster_offset != INV_OFFSET); |
| 1720 | |
Kevin Wolf | 83baa9a | 2013-03-26 17:50:04 +0100 | [diff] [blame] | 1721 | /* |
| 1722 | * Save info needed for meta data update. |
| 1723 | * |
Kevin Wolf | 8556739 | 2016-06-01 14:08:56 +0200 | [diff] [blame] | 1724 | * requested_bytes: Number of bytes from the start of the first |
Kevin Wolf | 83baa9a | 2013-03-26 17:50:04 +0100 | [diff] [blame] | 1725 | * newly allocated cluster to the end of the (possibly shortened |
| 1726 | * before) write request. |
| 1727 | * |
Kevin Wolf | 8556739 | 2016-06-01 14:08:56 +0200 | [diff] [blame] | 1728 | * avail_bytes: Number of bytes from the start of the first |
Kevin Wolf | 83baa9a | 2013-03-26 17:50:04 +0100 | [diff] [blame] | 1729 | * newly allocated to the end of the last newly allocated cluster. |
| 1730 | * |
Kevin Wolf | 8556739 | 2016-06-01 14:08:56 +0200 | [diff] [blame] | 1731 | * nb_bytes: The number of bytes from the start of the first |
Kevin Wolf | 83baa9a | 2013-03-26 17:50:04 +0100 | [diff] [blame] | 1732 | * newly allocated cluster to the end of the area that the write |
| 1733 | * request actually writes to (excluding COW at the end) |
| 1734 | */ |
Kevin Wolf | 8556739 | 2016-06-01 14:08:56 +0200 | [diff] [blame] | 1735 | uint64_t requested_bytes = *bytes + offset_into_cluster(s, guest_offset); |
Max Reitz | d1b9d19 | 2019-10-10 12:08:57 +0200 | [diff] [blame] | 1736 | int avail_bytes = nb_clusters << s->cluster_bits; |
Kevin Wolf | 8556739 | 2016-06-01 14:08:56 +0200 | [diff] [blame] | 1737 | int nb_bytes = MIN(requested_bytes, avail_bytes); |
Kevin Wolf | 83baa9a | 2013-03-26 17:50:04 +0100 | [diff] [blame] | 1738 | |
Kevin Wolf | 411d62b | 2013-03-26 17:50:09 +0100 | [diff] [blame] | 1739 | *host_offset = alloc_cluster_offset + offset_into_cluster(s, guest_offset); |
Kevin Wolf | 8556739 | 2016-06-01 14:08:56 +0200 | [diff] [blame] | 1740 | *bytes = MIN(*bytes, nb_bytes - offset_into_cluster(s, guest_offset)); |
Kevin Wolf | 83baa9a | 2013-03-26 17:50:04 +0100 | [diff] [blame] | 1741 | assert(*bytes != 0); |
| 1742 | |
Alberto Garcia | d53ec3d | 2020-07-10 18:13:02 +0200 | [diff] [blame] | 1743 | ret = calculate_l2_meta(bs, alloc_cluster_offset, guest_offset, *bytes, |
| 1744 | l2_slice, m, false); |
| 1745 | if (ret < 0) { |
| 1746 | goto out; |
| 1747 | } |
Alberto Garcia | 8f91d69 | 2020-07-10 18:12:45 +0200 | [diff] [blame] | 1748 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1749 | ret = 1; |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1750 | |
Alberto Garcia | 57538c8 | 2020-07-10 18:12:47 +0200 | [diff] [blame] | 1751 | out: |
| 1752 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1753 | return ret; |
| 1754 | } |
| 1755 | |
| 1756 | /* |
Alberto Garcia | 2b60c5b | 2020-09-03 18:37:49 +0200 | [diff] [blame] | 1757 | * For a given area on the virtual disk defined by @offset and @bytes, |
| 1758 | * find the corresponding area on the qcow2 image, allocating new |
| 1759 | * clusters (or subclusters) if necessary. The result can span a |
| 1760 | * combination of allocated and previously unallocated clusters. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1761 | * |
Alberto Garcia | bfd0989 | 2020-09-11 16:09:42 +0200 | [diff] [blame] | 1762 | * Note that offset may not be cluster aligned. In this case, the returned |
| 1763 | * *host_offset points to exact byte referenced by offset and therefore |
| 1764 | * isn't cluster aligned as well. |
| 1765 | * |
Alberto Garcia | 2b60c5b | 2020-09-03 18:37:49 +0200 | [diff] [blame] | 1766 | * On return, @host_offset is set to the beginning of the requested |
| 1767 | * area. This area is guaranteed to be contiguous on the qcow2 file |
| 1768 | * but it can be smaller than initially requested. In this case @bytes |
| 1769 | * is updated with the actual size. |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1770 | * |
Alberto Garcia | 2b60c5b | 2020-09-03 18:37:49 +0200 | [diff] [blame] | 1771 | * If any clusters or subclusters were allocated then @m contains a |
| 1772 | * list with the information of all the affected regions. Note that |
| 1773 | * this can happen regardless of whether this function succeeds or |
| 1774 | * not. The caller is responsible for updating the L2 metadata of the |
| 1775 | * allocated clusters (on success) or freeing them (on failure), and |
| 1776 | * for clearing the contents of @m afterwards in both cases. |
Kevin Wolf | 148da7e | 2010-01-20 15:03:01 +0100 | [diff] [blame] | 1777 | * |
Kevin Wolf | 68d100e | 2011-06-30 17:42:09 +0200 | [diff] [blame] | 1778 | * If the request conflicts with another write request in flight, the coroutine |
| 1779 | * is queued and will be reentered when the dependency has completed. |
Kevin Wolf | 148da7e | 2010-01-20 15:03:01 +0100 | [diff] [blame] | 1780 | * |
| 1781 | * Return 0 on success and -errno in error cases |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1782 | */ |
Paolo Bonzini | 050ed2e | 2022-09-22 10:49:12 +0200 | [diff] [blame] | 1783 | int coroutine_fn qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset, |
| 1784 | unsigned int *bytes, |
| 1785 | uint64_t *host_offset, |
| 1786 | QCowL2Meta **m) |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1787 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1788 | BDRVQcow2State *s = bs->opaque; |
Kevin Wolf | 710c249 | 2013-03-26 17:50:10 +0100 | [diff] [blame] | 1789 | uint64_t start, remaining; |
Kevin Wolf | 250196f | 2012-03-02 14:10:54 +0100 | [diff] [blame] | 1790 | uint64_t cluster_offset; |
Kevin Wolf | 65eb2e3 | 2013-03-26 17:49:58 +0100 | [diff] [blame] | 1791 | uint64_t cur_bytes; |
Kevin Wolf | 710c249 | 2013-03-26 17:50:10 +0100 | [diff] [blame] | 1792 | int ret; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1793 | |
Kevin Wolf | d46a0bb | 2016-06-01 16:55:05 +0200 | [diff] [blame] | 1794 | trace_qcow2_alloc_clusters_offset(qemu_coroutine_self(), offset, *bytes); |
Kevin Wolf | 710c249 | 2013-03-26 17:50:10 +0100 | [diff] [blame] | 1795 | |
Kevin Wolf | 7242411 | 2012-04-24 16:10:56 +0200 | [diff] [blame] | 1796 | again: |
Hu Tao | 16f0587 | 2014-01-26 11:12:37 +0800 | [diff] [blame] | 1797 | start = offset; |
Kevin Wolf | d46a0bb | 2016-06-01 16:55:05 +0200 | [diff] [blame] | 1798 | remaining = *bytes; |
Kevin Wolf | c6d619c | 2019-01-18 14:40:36 +0100 | [diff] [blame] | 1799 | cluster_offset = INV_OFFSET; |
| 1800 | *host_offset = INV_OFFSET; |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1801 | cur_bytes = 0; |
| 1802 | *m = NULL; |
Kevin Wolf | 0af729e | 2013-03-26 17:50:05 +0100 | [diff] [blame] | 1803 | |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1804 | while (true) { |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1805 | |
Kevin Wolf | c6d619c | 2019-01-18 14:40:36 +0100 | [diff] [blame] | 1806 | if (*host_offset == INV_OFFSET && cluster_offset != INV_OFFSET) { |
Alberto Garcia | bfd0989 | 2020-09-11 16:09:42 +0200 | [diff] [blame] | 1807 | *host_offset = cluster_offset; |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1808 | } |
| 1809 | |
| 1810 | assert(remaining >= cur_bytes); |
| 1811 | |
| 1812 | start += cur_bytes; |
| 1813 | remaining -= cur_bytes; |
Kevin Wolf | c6d619c | 2019-01-18 14:40:36 +0100 | [diff] [blame] | 1814 | |
| 1815 | if (cluster_offset != INV_OFFSET) { |
| 1816 | cluster_offset += cur_bytes; |
| 1817 | } |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1818 | |
| 1819 | if (remaining == 0) { |
| 1820 | break; |
| 1821 | } |
| 1822 | |
| 1823 | cur_bytes = remaining; |
| 1824 | |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1825 | /* |
| 1826 | * Now start gathering as many contiguous clusters as possible: |
| 1827 | * |
| 1828 | * 1. Check for overlaps with in-flight allocations |
| 1829 | * |
| 1830 | * a) Overlap not in the first cluster -> shorten this request and |
| 1831 | * let the caller handle the rest in its next loop iteration. |
| 1832 | * |
| 1833 | * b) Real overlaps of two requests. Yield and restart the search |
| 1834 | * for contiguous clusters (the situation could have changed |
| 1835 | * while we were sleeping) |
| 1836 | * |
| 1837 | * c) TODO: Request starts in the same cluster as the in-flight |
| 1838 | * allocation ends. Shorten the COW of the in-fight allocation, |
| 1839 | * set cluster_offset to write to the same cluster and set up |
| 1840 | * the right synchronisation between the in-flight request and |
| 1841 | * the new one. |
| 1842 | */ |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1843 | ret = handle_dependencies(bs, start, &cur_bytes, m); |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1844 | if (ret == -EAGAIN) { |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1845 | /* Currently handle_dependencies() doesn't yield if we already had |
| 1846 | * an allocation. If it did, we would have to clean up the L2Meta |
| 1847 | * structs before starting over. */ |
| 1848 | assert(*m == NULL); |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1849 | goto again; |
| 1850 | } else if (ret < 0) { |
| 1851 | return ret; |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1852 | } else if (cur_bytes == 0) { |
| 1853 | break; |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1854 | } else { |
| 1855 | /* handle_dependencies() may have decreased cur_bytes (shortened |
| 1856 | * the allocations below) so that the next dependency is processed |
| 1857 | * correctly during the next loop iteration. */ |
Kevin Wolf | 710c249 | 2013-03-26 17:50:10 +0100 | [diff] [blame] | 1858 | } |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1859 | |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1860 | /* |
| 1861 | * 2. Count contiguous COPIED clusters. |
| 1862 | */ |
| 1863 | ret = handle_copied(bs, start, &cluster_offset, &cur_bytes, m); |
| 1864 | if (ret < 0) { |
| 1865 | return ret; |
| 1866 | } else if (ret) { |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1867 | continue; |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1868 | } else if (cur_bytes == 0) { |
| 1869 | break; |
| 1870 | } |
| 1871 | |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1872 | /* |
| 1873 | * 3. If the request still hasn't completed, allocate new clusters, |
| 1874 | * considering any cluster_offset of steps 1c or 2. |
| 1875 | */ |
| 1876 | ret = handle_alloc(bs, start, &cluster_offset, &cur_bytes, m); |
| 1877 | if (ret < 0) { |
| 1878 | return ret; |
| 1879 | } else if (ret) { |
Kevin Wolf | ecdd533 | 2013-03-27 11:43:49 +0100 | [diff] [blame] | 1880 | continue; |
Kevin Wolf | 2c3b32d | 2013-03-26 17:50:12 +0100 | [diff] [blame] | 1881 | } else { |
| 1882 | assert(cur_bytes == 0); |
| 1883 | break; |
| 1884 | } |
Kevin Wolf | f5bc635 | 2013-03-26 17:50:01 +0100 | [diff] [blame] | 1885 | } |
Kevin Wolf | 10f0ed8 | 2013-03-26 17:50:00 +0100 | [diff] [blame] | 1886 | |
Kevin Wolf | d46a0bb | 2016-06-01 16:55:05 +0200 | [diff] [blame] | 1887 | *bytes -= remaining; |
| 1888 | assert(*bytes > 0); |
Kevin Wolf | c6d619c | 2019-01-18 14:40:36 +0100 | [diff] [blame] | 1889 | assert(*host_offset != INV_OFFSET); |
Alberto Garcia | bfd0989 | 2020-09-11 16:09:42 +0200 | [diff] [blame] | 1890 | assert(offset_into_cluster(s, *host_offset) == |
| 1891 | offset_into_cluster(s, offset)); |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1892 | |
Kevin Wolf | 148da7e | 2010-01-20 15:03:01 +0100 | [diff] [blame] | 1893 | return 0; |
Kevin Wolf | 45aba42 | 2009-05-28 16:07:05 +0200 | [diff] [blame] | 1894 | } |
| 1895 | |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1896 | /* |
| 1897 | * This discards as many clusters of nb_clusters as possible at once (i.e. |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 1898 | * all clusters in the same L2 slice) and returns the number of discarded |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1899 | * clusters. |
| 1900 | */ |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 1901 | static int discard_in_l2_slice(BlockDriverState *bs, uint64_t offset, |
| 1902 | uint64_t nb_clusters, |
| 1903 | enum qcow2_discard_type type, bool full_discard) |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1904 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1905 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 1906 | uint64_t *l2_slice; |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1907 | int l2_index; |
| 1908 | int ret; |
| 1909 | int i; |
| 1910 | |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 1911 | ret = get_cluster_table(bs, offset, &l2_slice, &l2_index); |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1912 | if (ret < 0) { |
| 1913 | return ret; |
| 1914 | } |
| 1915 | |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 1916 | /* Limit nb_clusters to one L2 slice */ |
| 1917 | nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index); |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 1918 | assert(nb_clusters <= INT_MAX); |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1919 | |
| 1920 | for (i = 0; i < nb_clusters; i++) { |
Alberto Garcia | a68cd70 | 2020-07-10 18:13:05 +0200 | [diff] [blame] | 1921 | uint64_t old_l2_entry = get_l2_entry(s, l2_slice, l2_index + i); |
| 1922 | uint64_t old_l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index + i); |
| 1923 | uint64_t new_l2_entry = old_l2_entry; |
| 1924 | uint64_t new_l2_bitmap = old_l2_bitmap; |
| 1925 | QCow2ClusterType cluster_type = |
| 1926 | qcow2_get_cluster_type(bs, old_l2_entry); |
Jean-Louis Dupond | 42a2890 | 2023-06-05 10:45:24 +0200 | [diff] [blame] | 1927 | bool keep_reference = (cluster_type != QCOW2_CLUSTER_COMPRESSED) && |
| 1928 | !full_discard && |
| 1929 | (s->discard_no_unref && |
| 1930 | type == QCOW2_DISCARD_REQUEST); |
Kevin Wolf | a71835a | 2014-02-08 14:38:33 +0100 | [diff] [blame] | 1931 | |
| 1932 | /* |
Alberto Garcia | a68cd70 | 2020-07-10 18:13:05 +0200 | [diff] [blame] | 1933 | * If full_discard is true, the cluster should not read back as zeroes, |
| 1934 | * but rather fall through to the backing file. |
| 1935 | * |
Max Reitz | 808c4b6 | 2014-10-24 15:57:30 +0200 | [diff] [blame] | 1936 | * If full_discard is false, make sure that a discarded area reads back |
| 1937 | * as zeroes for v3 images (we cannot do it for v2 without actually |
| 1938 | * writing a zero-filled buffer). We can skip the operation if the |
| 1939 | * cluster is already marked as zero, or if it's unallocated and we |
| 1940 | * don't have a backing file. |
Kevin Wolf | a71835a | 2014-02-08 14:38:33 +0100 | [diff] [blame] | 1941 | * |
Eric Blake | 237d78f | 2017-10-11 22:47:03 -0500 | [diff] [blame] | 1942 | * TODO We might want to use bdrv_block_status(bs) here, but we're |
Kevin Wolf | a71835a | 2014-02-08 14:38:33 +0100 | [diff] [blame] | 1943 | * holding s->lock, so that doesn't work today. |
| 1944 | */ |
Alberto Garcia | a68cd70 | 2020-07-10 18:13:05 +0200 | [diff] [blame] | 1945 | if (full_discard) { |
| 1946 | new_l2_entry = new_l2_bitmap = 0; |
| 1947 | } else if (bs->backing || qcow2_cluster_is_allocated(cluster_type)) { |
| 1948 | if (has_subclusters(s)) { |
Jean-Louis Dupond | 42a2890 | 2023-06-05 10:45:24 +0200 | [diff] [blame] | 1949 | if (keep_reference) { |
| 1950 | new_l2_entry = old_l2_entry; |
| 1951 | } else { |
| 1952 | new_l2_entry = 0; |
| 1953 | } |
Alberto Garcia | a68cd70 | 2020-07-10 18:13:05 +0200 | [diff] [blame] | 1954 | new_l2_bitmap = QCOW_L2_BITMAP_ALL_ZEROES; |
| 1955 | } else { |
Jean-Louis Dupond | 42a2890 | 2023-06-05 10:45:24 +0200 | [diff] [blame] | 1956 | if (s->qcow_version >= 3) { |
| 1957 | if (keep_reference) { |
| 1958 | new_l2_entry |= QCOW_OFLAG_ZERO; |
| 1959 | } else { |
| 1960 | new_l2_entry = QCOW_OFLAG_ZERO; |
| 1961 | } |
| 1962 | } else { |
| 1963 | new_l2_entry = 0; |
| 1964 | } |
Eric Blake | bbd995d | 2017-05-06 19:05:42 -0500 | [diff] [blame] | 1965 | } |
Alberto Garcia | a68cd70 | 2020-07-10 18:13:05 +0200 | [diff] [blame] | 1966 | } |
Kevin Wolf | a71835a | 2014-02-08 14:38:33 +0100 | [diff] [blame] | 1967 | |
Alberto Garcia | a68cd70 | 2020-07-10 18:13:05 +0200 | [diff] [blame] | 1968 | if (old_l2_entry == new_l2_entry && old_l2_bitmap == new_l2_bitmap) { |
| 1969 | continue; |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1970 | } |
| 1971 | |
| 1972 | /* First remove L2 entries */ |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 1973 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); |
Alberto Garcia | a68cd70 | 2020-07-10 18:13:05 +0200 | [diff] [blame] | 1974 | set_l2_entry(s, l2_slice, l2_index + i, new_l2_entry); |
| 1975 | if (has_subclusters(s)) { |
| 1976 | set_l2_bitmap(s, l2_slice, l2_index + i, new_l2_bitmap); |
Kevin Wolf | a71835a | 2014-02-08 14:38:33 +0100 | [diff] [blame] | 1977 | } |
Jean-Louis Dupond | 42a2890 | 2023-06-05 10:45:24 +0200 | [diff] [blame] | 1978 | if (!keep_reference) { |
| 1979 | /* Then decrease the refcount */ |
| 1980 | qcow2_free_any_cluster(bs, old_l2_entry, type); |
| 1981 | } else if (s->discard_passthrough[type] && |
| 1982 | (cluster_type == QCOW2_CLUSTER_NORMAL || |
| 1983 | cluster_type == QCOW2_CLUSTER_ZERO_ALLOC)) { |
| 1984 | /* If we keep the reference, pass on the discard still */ |
| 1985 | bdrv_pdiscard(s->data_file, old_l2_entry & L2E_OFFSET_MASK, |
| 1986 | s->cluster_size); |
| 1987 | } |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1988 | } |
| 1989 | |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 1990 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1991 | |
| 1992 | return nb_clusters; |
| 1993 | } |
| 1994 | |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 1995 | int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset, |
| 1996 | uint64_t bytes, enum qcow2_discard_type type, |
| 1997 | bool full_discard) |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 1998 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 1999 | BDRVQcow2State *s = bs->opaque; |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2000 | uint64_t end_offset = offset + bytes; |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 2001 | uint64_t nb_clusters; |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2002 | int64_t cleared; |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 2003 | int ret; |
| 2004 | |
Eric Blake | f10ee13 | 2017-05-06 19:05:51 -0500 | [diff] [blame] | 2005 | /* Caller must pass aligned values, except at image end */ |
Eric Blake | 0c1bd46 | 2017-03-31 13:53:55 -0500 | [diff] [blame] | 2006 | assert(QEMU_IS_ALIGNED(offset, s->cluster_size)); |
Eric Blake | f10ee13 | 2017-05-06 19:05:51 -0500 | [diff] [blame] | 2007 | assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) || |
| 2008 | end_offset == bs->total_sectors << BDRV_SECTOR_BITS); |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 2009 | |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2010 | nb_clusters = size_to_clusters(s, bytes); |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 2011 | |
Kevin Wolf | 0b919fa | 2013-06-19 13:44:20 +0200 | [diff] [blame] | 2012 | s->cache_discards = true; |
| 2013 | |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 2014 | /* Each L2 slice is handled by its own loop iteration */ |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 2015 | while (nb_clusters > 0) { |
Alberto Garcia | 21ab3ad | 2018-02-05 16:33:24 +0200 | [diff] [blame] | 2016 | cleared = discard_in_l2_slice(bs, offset, nb_clusters, type, |
| 2017 | full_discard); |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2018 | if (cleared < 0) { |
| 2019 | ret = cleared; |
Kevin Wolf | 0b919fa | 2013-06-19 13:44:20 +0200 | [diff] [blame] | 2020 | goto fail; |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 2021 | } |
| 2022 | |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2023 | nb_clusters -= cleared; |
| 2024 | offset += (cleared * s->cluster_size); |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 2025 | } |
| 2026 | |
Kevin Wolf | 0b919fa | 2013-06-19 13:44:20 +0200 | [diff] [blame] | 2027 | ret = 0; |
| 2028 | fail: |
| 2029 | s->cache_discards = false; |
| 2030 | qcow2_process_discards(bs, ret); |
| 2031 | |
| 2032 | return ret; |
Kevin Wolf | 5ea929e | 2011-01-26 16:56:48 +0100 | [diff] [blame] | 2033 | } |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2034 | |
| 2035 | /* |
| 2036 | * This zeroes as many clusters of nb_clusters as possible at once (i.e. |
Alberto Garcia | a9a9f8f | 2018-02-05 16:33:25 +0200 | [diff] [blame] | 2037 | * all clusters in the same L2 slice) and returns the number of zeroed |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2038 | * clusters. |
| 2039 | */ |
Paolo Bonzini | 70bacc4 | 2023-06-01 13:51:43 +0200 | [diff] [blame] | 2040 | static int coroutine_fn |
| 2041 | zero_in_l2_slice(BlockDriverState *bs, uint64_t offset, |
| 2042 | uint64_t nb_clusters, int flags) |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2043 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 2044 | BDRVQcow2State *s = bs->opaque; |
Alberto Garcia | a9a9f8f | 2018-02-05 16:33:25 +0200 | [diff] [blame] | 2045 | uint64_t *l2_slice; |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2046 | int l2_index; |
| 2047 | int ret; |
| 2048 | int i; |
| 2049 | |
Alberto Garcia | a9a9f8f | 2018-02-05 16:33:25 +0200 | [diff] [blame] | 2050 | ret = get_cluster_table(bs, offset, &l2_slice, &l2_index); |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2051 | if (ret < 0) { |
| 2052 | return ret; |
| 2053 | } |
| 2054 | |
Alberto Garcia | a9a9f8f | 2018-02-05 16:33:25 +0200 | [diff] [blame] | 2055 | /* Limit nb_clusters to one L2 slice */ |
| 2056 | nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index); |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 2057 | assert(nb_clusters <= INT_MAX); |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2058 | |
| 2059 | for (i = 0; i < nb_clusters; i++) { |
Alberto Garcia | 205fa50 | 2020-07-10 18:13:04 +0200 | [diff] [blame] | 2060 | uint64_t old_l2_entry = get_l2_entry(s, l2_slice, l2_index + i); |
| 2061 | uint64_t old_l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index + i); |
| 2062 | QCow2ClusterType type = qcow2_get_cluster_type(bs, old_l2_entry); |
| 2063 | bool unmap = (type == QCOW2_CLUSTER_COMPRESSED) || |
| 2064 | ((flags & BDRV_REQ_MAY_UNMAP) && qcow2_cluster_is_allocated(type)); |
| 2065 | uint64_t new_l2_entry = unmap ? 0 : old_l2_entry; |
| 2066 | uint64_t new_l2_bitmap = old_l2_bitmap; |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2067 | |
Alberto Garcia | 205fa50 | 2020-07-10 18:13:04 +0200 | [diff] [blame] | 2068 | if (has_subclusters(s)) { |
| 2069 | new_l2_bitmap = QCOW_L2_BITMAP_ALL_ZEROES; |
| 2070 | } else { |
| 2071 | new_l2_entry |= QCOW_OFLAG_ZERO; |
| 2072 | } |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2073 | |
Alberto Garcia | 205fa50 | 2020-07-10 18:13:04 +0200 | [diff] [blame] | 2074 | if (old_l2_entry == new_l2_entry && old_l2_bitmap == new_l2_bitmap) { |
Eric Blake | 06cc5e2 | 2017-05-06 19:05:47 -0500 | [diff] [blame] | 2075 | continue; |
| 2076 | } |
| 2077 | |
Maxim Levitsky | c8bf9a9 | 2020-11-24 10:28:15 +0100 | [diff] [blame] | 2078 | /* First update L2 entries */ |
Alberto Garcia | a9a9f8f | 2018-02-05 16:33:25 +0200 | [diff] [blame] | 2079 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); |
Alberto Garcia | 205fa50 | 2020-07-10 18:13:04 +0200 | [diff] [blame] | 2080 | set_l2_entry(s, l2_slice, l2_index + i, new_l2_entry); |
| 2081 | if (has_subclusters(s)) { |
| 2082 | set_l2_bitmap(s, l2_slice, l2_index + i, new_l2_bitmap); |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2083 | } |
Maxim Levitsky | c8bf9a9 | 2020-11-24 10:28:15 +0100 | [diff] [blame] | 2084 | |
| 2085 | /* Then decrease the refcount */ |
| 2086 | if (unmap) { |
| 2087 | qcow2_free_any_cluster(bs, old_l2_entry, QCOW2_DISCARD_REQUEST); |
| 2088 | } |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2089 | } |
| 2090 | |
Alberto Garcia | a9a9f8f | 2018-02-05 16:33:25 +0200 | [diff] [blame] | 2091 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2092 | |
| 2093 | return nb_clusters; |
| 2094 | } |
| 2095 | |
Paolo Bonzini | a39bae4 | 2023-03-09 09:44:55 +0100 | [diff] [blame] | 2096 | static int coroutine_fn |
| 2097 | zero_l2_subclusters(BlockDriverState *bs, uint64_t offset, |
| 2098 | unsigned nb_subclusters) |
Alberto Garcia | a6841a2 | 2020-07-10 18:13:10 +0200 | [diff] [blame] | 2099 | { |
| 2100 | BDRVQcow2State *s = bs->opaque; |
| 2101 | uint64_t *l2_slice; |
| 2102 | uint64_t old_l2_bitmap, l2_bitmap; |
| 2103 | int l2_index, ret, sc = offset_to_sc_index(s, offset); |
| 2104 | |
| 2105 | /* For full clusters use zero_in_l2_slice() instead */ |
| 2106 | assert(nb_subclusters > 0 && nb_subclusters < s->subclusters_per_cluster); |
| 2107 | assert(sc + nb_subclusters <= s->subclusters_per_cluster); |
| 2108 | assert(offset_into_subcluster(s, offset) == 0); |
| 2109 | |
| 2110 | ret = get_cluster_table(bs, offset, &l2_slice, &l2_index); |
| 2111 | if (ret < 0) { |
| 2112 | return ret; |
| 2113 | } |
| 2114 | |
| 2115 | switch (qcow2_get_cluster_type(bs, get_l2_entry(s, l2_slice, l2_index))) { |
| 2116 | case QCOW2_CLUSTER_COMPRESSED: |
| 2117 | ret = -ENOTSUP; /* We cannot partially zeroize compressed clusters */ |
| 2118 | goto out; |
| 2119 | case QCOW2_CLUSTER_NORMAL: |
| 2120 | case QCOW2_CLUSTER_UNALLOCATED: |
| 2121 | break; |
| 2122 | default: |
| 2123 | g_assert_not_reached(); |
| 2124 | } |
| 2125 | |
| 2126 | old_l2_bitmap = l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index); |
| 2127 | |
| 2128 | l2_bitmap |= QCOW_OFLAG_SUB_ZERO_RANGE(sc, sc + nb_subclusters); |
| 2129 | l2_bitmap &= ~QCOW_OFLAG_SUB_ALLOC_RANGE(sc, sc + nb_subclusters); |
| 2130 | |
| 2131 | if (old_l2_bitmap != l2_bitmap) { |
| 2132 | set_l2_bitmap(s, l2_slice, l2_index, l2_bitmap); |
| 2133 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); |
| 2134 | } |
| 2135 | |
| 2136 | ret = 0; |
| 2137 | out: |
| 2138 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
| 2139 | |
| 2140 | return ret; |
| 2141 | } |
| 2142 | |
Paolo Bonzini | 050ed2e | 2022-09-22 10:49:12 +0200 | [diff] [blame] | 2143 | int coroutine_fn qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, |
| 2144 | uint64_t bytes, int flags) |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2145 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 2146 | BDRVQcow2State *s = bs->opaque; |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2147 | uint64_t end_offset = offset + bytes; |
Max Reitz | b6d36de | 2015-09-14 16:39:47 +0200 | [diff] [blame] | 2148 | uint64_t nb_clusters; |
Alberto Garcia | a6841a2 | 2020-07-10 18:13:10 +0200 | [diff] [blame] | 2149 | unsigned head, tail; |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2150 | int64_t cleared; |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2151 | int ret; |
| 2152 | |
Kevin Wolf | 6c3944d | 2019-02-22 14:29:38 +0100 | [diff] [blame] | 2153 | /* If we have to stay in sync with an external data file, zero out |
| 2154 | * s->data_file first. */ |
| 2155 | if (data_file_is_raw(bs)) { |
| 2156 | assert(has_data_file(bs)); |
| 2157 | ret = bdrv_co_pwrite_zeroes(s->data_file, offset, bytes, flags); |
| 2158 | if (ret < 0) { |
| 2159 | return ret; |
| 2160 | } |
| 2161 | } |
| 2162 | |
Eric Blake | f10ee13 | 2017-05-06 19:05:51 -0500 | [diff] [blame] | 2163 | /* Caller must pass aligned values, except at image end */ |
Alberto Garcia | a6841a2 | 2020-07-10 18:13:10 +0200 | [diff] [blame] | 2164 | assert(offset_into_subcluster(s, offset) == 0); |
| 2165 | assert(offset_into_subcluster(s, end_offset) == 0 || |
Kevin Wolf | f01643f | 2020-04-24 14:54:42 +0200 | [diff] [blame] | 2166 | end_offset >= bs->total_sectors << BDRV_SECTOR_BITS); |
Eric Blake | f10ee13 | 2017-05-06 19:05:51 -0500 | [diff] [blame] | 2167 | |
Kevin Wolf | 61b3043 | 2020-07-21 15:55:19 +0200 | [diff] [blame] | 2168 | /* |
| 2169 | * The zero flag is only supported by version 3 and newer. However, if we |
| 2170 | * have no backing file, we can resort to discard in version 2. |
| 2171 | */ |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2172 | if (s->qcow_version < 3) { |
Kevin Wolf | 61b3043 | 2020-07-21 15:55:19 +0200 | [diff] [blame] | 2173 | if (!bs->backing) { |
| 2174 | return qcow2_cluster_discard(bs, offset, bytes, |
| 2175 | QCOW2_DISCARD_REQUEST, false); |
| 2176 | } |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2177 | return -ENOTSUP; |
| 2178 | } |
| 2179 | |
Alberto Garcia | a6841a2 | 2020-07-10 18:13:10 +0200 | [diff] [blame] | 2180 | head = MIN(end_offset, ROUND_UP(offset, s->cluster_size)) - offset; |
| 2181 | offset += head; |
| 2182 | |
| 2183 | tail = (end_offset >= bs->total_sectors << BDRV_SECTOR_BITS) ? 0 : |
| 2184 | end_offset - MAX(offset, start_of_cluster(s, end_offset)); |
| 2185 | end_offset -= tail; |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2186 | |
Kevin Wolf | 0b919fa | 2013-06-19 13:44:20 +0200 | [diff] [blame] | 2187 | s->cache_discards = true; |
| 2188 | |
Alberto Garcia | a6841a2 | 2020-07-10 18:13:10 +0200 | [diff] [blame] | 2189 | if (head) { |
| 2190 | ret = zero_l2_subclusters(bs, offset - head, |
| 2191 | size_to_subclusters(s, head)); |
| 2192 | if (ret < 0) { |
| 2193 | goto fail; |
| 2194 | } |
| 2195 | } |
| 2196 | |
| 2197 | /* Each L2 slice is handled by its own loop iteration */ |
| 2198 | nb_clusters = size_to_clusters(s, end_offset - offset); |
| 2199 | |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2200 | while (nb_clusters > 0) { |
Alberto Garcia | a9a9f8f | 2018-02-05 16:33:25 +0200 | [diff] [blame] | 2201 | cleared = zero_in_l2_slice(bs, offset, nb_clusters, flags); |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2202 | if (cleared < 0) { |
| 2203 | ret = cleared; |
Kevin Wolf | 0b919fa | 2013-06-19 13:44:20 +0200 | [diff] [blame] | 2204 | goto fail; |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2205 | } |
| 2206 | |
Eric Blake | d2cb36a | 2017-05-06 19:05:52 -0500 | [diff] [blame] | 2207 | nb_clusters -= cleared; |
| 2208 | offset += (cleared * s->cluster_size); |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2209 | } |
| 2210 | |
Alberto Garcia | a6841a2 | 2020-07-10 18:13:10 +0200 | [diff] [blame] | 2211 | if (tail) { |
| 2212 | ret = zero_l2_subclusters(bs, end_offset, size_to_subclusters(s, tail)); |
| 2213 | if (ret < 0) { |
| 2214 | goto fail; |
| 2215 | } |
| 2216 | } |
| 2217 | |
Kevin Wolf | 0b919fa | 2013-06-19 13:44:20 +0200 | [diff] [blame] | 2218 | ret = 0; |
| 2219 | fail: |
| 2220 | s->cache_discards = false; |
| 2221 | qcow2_process_discards(bs, ret); |
| 2222 | |
| 2223 | return ret; |
Kevin Wolf | 621f058 | 2012-03-20 15:12:58 +0100 | [diff] [blame] | 2224 | } |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2225 | |
| 2226 | /* |
| 2227 | * Expands all zero clusters in a specific L1 table (or deallocates them, for |
| 2228 | * non-backed non-pre-allocated zero clusters). |
| 2229 | * |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2230 | * l1_entries and *visited_l1_entries are used to keep track of progress for |
| 2231 | * status_cb(). l1_entries contains the total number of L1 entries and |
| 2232 | * *visited_l1_entries counts all visited L1 entries. |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2233 | */ |
| 2234 | static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, |
Max Reitz | ecf5877 | 2014-10-27 11:12:55 +0100 | [diff] [blame] | 2235 | int l1_size, int64_t *visited_l1_entries, |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2236 | int64_t l1_entries, |
Max Reitz | 8b13976 | 2015-07-27 17:51:32 +0200 | [diff] [blame] | 2237 | BlockDriverAmendStatusCB *status_cb, |
| 2238 | void *cb_opaque) |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2239 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 2240 | BDRVQcow2State *s = bs->opaque; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2241 | bool is_active_l1 = (l1_table == s->l1_table); |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2242 | uint64_t *l2_slice = NULL; |
| 2243 | unsigned slice, slice_size2, n_slices; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2244 | int ret; |
| 2245 | int i, j; |
| 2246 | |
Alberto Garcia | 7bbb592 | 2020-07-10 18:13:15 +0200 | [diff] [blame] | 2247 | /* qcow2_downgrade() is not allowed in images with subclusters */ |
| 2248 | assert(!has_subclusters(s)); |
| 2249 | |
Alberto Garcia | c8fd855 | 2020-07-10 18:12:54 +0200 | [diff] [blame] | 2250 | slice_size2 = s->l2_slice_size * l2_entry_size(s); |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2251 | n_slices = s->cluster_size / slice_size2; |
| 2252 | |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2253 | if (!is_active_l1) { |
| 2254 | /* inactive L2 tables require a buffer to be stored in when loading |
| 2255 | * them from disk */ |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2256 | l2_slice = qemu_try_blockalign(bs->file->bs, slice_size2); |
| 2257 | if (l2_slice == NULL) { |
Kevin Wolf | de82815 | 2014-05-20 17:12:47 +0200 | [diff] [blame] | 2258 | return -ENOMEM; |
| 2259 | } |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2260 | } |
| 2261 | |
| 2262 | for (i = 0; i < l1_size; i++) { |
| 2263 | uint64_t l2_offset = l1_table[i] & L1E_OFFSET_MASK; |
Max Reitz | 0e06528 | 2015-02-10 15:28:48 -0500 | [diff] [blame] | 2264 | uint64_t l2_refcount; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2265 | |
| 2266 | if (!l2_offset) { |
| 2267 | /* unallocated */ |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2268 | (*visited_l1_entries)++; |
| 2269 | if (status_cb) { |
Max Reitz | 8b13976 | 2015-07-27 17:51:32 +0200 | [diff] [blame] | 2270 | status_cb(bs, *visited_l1_entries, l1_entries, cb_opaque); |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2271 | } |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2272 | continue; |
| 2273 | } |
| 2274 | |
Max Reitz | 8dd93d9 | 2015-01-19 15:49:03 -0500 | [diff] [blame] | 2275 | if (offset_into_cluster(s, l2_offset)) { |
| 2276 | qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" |
| 2277 | PRIx64 " unaligned (L1 index: %#x)", |
| 2278 | l2_offset, i); |
| 2279 | ret = -EIO; |
| 2280 | goto fail; |
| 2281 | } |
| 2282 | |
Alberto Garcia | 9b76548 | 2018-02-05 16:33:28 +0200 | [diff] [blame] | 2283 | ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, |
| 2284 | &l2_refcount); |
| 2285 | if (ret < 0) { |
| 2286 | goto fail; |
| 2287 | } |
| 2288 | |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2289 | for (slice = 0; slice < n_slices; slice++) { |
| 2290 | uint64_t slice_offset = l2_offset + slice * slice_size2; |
| 2291 | bool l2_dirty = false; |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2292 | if (is_active_l1) { |
| 2293 | /* get active L2 tables from cache */ |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2294 | ret = qcow2_cache_get(bs, s->l2_table_cache, slice_offset, |
| 2295 | (void **)&l2_slice); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2296 | } else { |
| 2297 | /* load inactive L2 tables from disk */ |
Alberto Faria | 32cc71d | 2022-06-09 16:27:36 +0100 | [diff] [blame] | 2298 | ret = bdrv_pread(bs->file, slice_offset, slice_size2, |
| 2299 | l2_slice, 0); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2300 | } |
| 2301 | if (ret < 0) { |
| 2302 | goto fail; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2303 | } |
| 2304 | |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2305 | for (j = 0; j < s->l2_slice_size; j++) { |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 2306 | uint64_t l2_entry = get_l2_entry(s, l2_slice, j); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2307 | int64_t offset = l2_entry & L2E_OFFSET_MASK; |
| 2308 | QCow2ClusterType cluster_type = |
Kevin Wolf | 808c2bb | 2019-01-17 18:42:40 +0100 | [diff] [blame] | 2309 | qcow2_get_cluster_type(bs, l2_entry); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2310 | |
| 2311 | if (cluster_type != QCOW2_CLUSTER_ZERO_PLAIN && |
| 2312 | cluster_type != QCOW2_CLUSTER_ZERO_ALLOC) { |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2313 | continue; |
| 2314 | } |
| 2315 | |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2316 | if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) { |
| 2317 | if (!bs->backing) { |
Alberto Garcia | 7bbb592 | 2020-07-10 18:13:15 +0200 | [diff] [blame] | 2318 | /* |
| 2319 | * not backed; therefore we can simply deallocate the |
| 2320 | * cluster. No need to call set_l2_bitmap(), this |
| 2321 | * function doesn't support images with subclusters. |
| 2322 | */ |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 2323 | set_l2_entry(s, l2_slice, j, 0); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2324 | l2_dirty = true; |
| 2325 | continue; |
| 2326 | } |
Max Reitz | ecf5877 | 2014-10-27 11:12:55 +0100 | [diff] [blame] | 2327 | |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2328 | offset = qcow2_alloc_clusters(bs, s->cluster_size); |
| 2329 | if (offset < 0) { |
| 2330 | ret = offset; |
Max Reitz | ecf5877 | 2014-10-27 11:12:55 +0100 | [diff] [blame] | 2331 | goto fail; |
| 2332 | } |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2333 | |
Alberto Garcia | 3a75a87 | 2020-01-13 17:11:46 +0100 | [diff] [blame] | 2334 | /* The offset must fit in the offset field */ |
| 2335 | assert((offset & L2E_OFFSET_MASK) == offset); |
| 2336 | |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2337 | if (l2_refcount > 1) { |
| 2338 | /* For shared L2 tables, set the refcount accordingly |
| 2339 | * (it is already 1 and needs to be l2_refcount) */ |
| 2340 | ret = qcow2_update_cluster_refcount( |
| 2341 | bs, offset >> s->cluster_bits, |
| 2342 | refcount_diff(1, l2_refcount), false, |
| 2343 | QCOW2_DISCARD_OTHER); |
| 2344 | if (ret < 0) { |
| 2345 | qcow2_free_clusters(bs, offset, s->cluster_size, |
| 2346 | QCOW2_DISCARD_OTHER); |
| 2347 | goto fail; |
| 2348 | } |
| 2349 | } |
Max Reitz | ecf5877 | 2014-10-27 11:12:55 +0100 | [diff] [blame] | 2350 | } |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2351 | |
| 2352 | if (offset_into_cluster(s, offset)) { |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2353 | int l2_index = slice * s->l2_slice_size + j; |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2354 | qcow2_signal_corruption( |
| 2355 | bs, true, -1, -1, |
| 2356 | "Cluster allocation offset " |
| 2357 | "%#" PRIx64 " unaligned (L2 offset: %#" |
| 2358 | PRIx64 ", L2 index: %#x)", offset, |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2359 | l2_offset, l2_index); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2360 | if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) { |
| 2361 | qcow2_free_clusters(bs, offset, s->cluster_size, |
| 2362 | QCOW2_DISCARD_ALWAYS); |
| 2363 | } |
| 2364 | ret = -EIO; |
| 2365 | goto fail; |
| 2366 | } |
| 2367 | |
| 2368 | ret = qcow2_pre_write_overlap_check(bs, 0, offset, |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 2369 | s->cluster_size, true); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2370 | if (ret < 0) { |
| 2371 | if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) { |
| 2372 | qcow2_free_clusters(bs, offset, s->cluster_size, |
| 2373 | QCOW2_DISCARD_ALWAYS); |
| 2374 | } |
| 2375 | goto fail; |
| 2376 | } |
| 2377 | |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 2378 | ret = bdrv_pwrite_zeroes(s->data_file, offset, |
| 2379 | s->cluster_size, 0); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2380 | if (ret < 0) { |
| 2381 | if (cluster_type == QCOW2_CLUSTER_ZERO_PLAIN) { |
| 2382 | qcow2_free_clusters(bs, offset, s->cluster_size, |
| 2383 | QCOW2_DISCARD_ALWAYS); |
| 2384 | } |
| 2385 | goto fail; |
| 2386 | } |
| 2387 | |
| 2388 | if (l2_refcount == 1) { |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 2389 | set_l2_entry(s, l2_slice, j, offset | QCOW_OFLAG_COPIED); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2390 | } else { |
Alberto Garcia | 12c6aeb | 2020-07-10 18:12:48 +0200 | [diff] [blame] | 2391 | set_l2_entry(s, l2_slice, j, offset); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2392 | } |
Alberto Garcia | 7bbb592 | 2020-07-10 18:13:15 +0200 | [diff] [blame] | 2393 | /* |
| 2394 | * No need to call set_l2_bitmap() after set_l2_entry() because |
| 2395 | * this function doesn't support images with subclusters. |
| 2396 | */ |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2397 | l2_dirty = true; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2398 | } |
| 2399 | |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2400 | if (is_active_l1) { |
| 2401 | if (l2_dirty) { |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2402 | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2403 | qcow2_cache_depends_on_flush(s->l2_table_cache); |
Max Reitz | 8dd93d9 | 2015-01-19 15:49:03 -0500 | [diff] [blame] | 2404 | } |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2405 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Max Reitz | ecf5877 | 2014-10-27 11:12:55 +0100 | [diff] [blame] | 2406 | } else { |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2407 | if (l2_dirty) { |
| 2408 | ret = qcow2_pre_write_overlap_check( |
| 2409 | bs, QCOW2_OL_INACTIVE_L2 | QCOW2_OL_ACTIVE_L2, |
Kevin Wolf | 966b000 | 2019-01-15 20:39:06 +0100 | [diff] [blame] | 2410 | slice_offset, slice_size2, false); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2411 | if (ret < 0) { |
| 2412 | goto fail; |
| 2413 | } |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2414 | |
Alberto Faria | 32cc71d | 2022-06-09 16:27:36 +0100 | [diff] [blame] | 2415 | ret = bdrv_pwrite(bs->file, slice_offset, slice_size2, |
| 2416 | l2_slice, 0); |
Alberto Garcia | 226494f | 2018-02-05 16:33:29 +0200 | [diff] [blame] | 2417 | if (ret < 0) { |
| 2418 | goto fail; |
| 2419 | } |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2420 | } |
| 2421 | } |
| 2422 | } |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2423 | |
| 2424 | (*visited_l1_entries)++; |
| 2425 | if (status_cb) { |
Max Reitz | 8b13976 | 2015-07-27 17:51:32 +0200 | [diff] [blame] | 2426 | status_cb(bs, *visited_l1_entries, l1_entries, cb_opaque); |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2427 | } |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2428 | } |
| 2429 | |
| 2430 | ret = 0; |
| 2431 | |
| 2432 | fail: |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2433 | if (l2_slice) { |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2434 | if (!is_active_l1) { |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2435 | qemu_vfree(l2_slice); |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2436 | } else { |
Alberto Garcia | 415184f | 2018-02-05 16:33:30 +0200 | [diff] [blame] | 2437 | qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2438 | } |
| 2439 | } |
| 2440 | return ret; |
| 2441 | } |
| 2442 | |
| 2443 | /* |
| 2444 | * For backed images, expands all zero clusters on the image. For non-backed |
| 2445 | * images, deallocates all non-pre-allocated zero clusters (and claims the |
| 2446 | * allocation for pre-allocated ones). This is important for downgrading to a |
| 2447 | * qcow2 version which doesn't yet support metadata zero clusters. |
| 2448 | */ |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2449 | int qcow2_expand_zero_clusters(BlockDriverState *bs, |
Max Reitz | 8b13976 | 2015-07-27 17:51:32 +0200 | [diff] [blame] | 2450 | BlockDriverAmendStatusCB *status_cb, |
| 2451 | void *cb_opaque) |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2452 | { |
Kevin Wolf | ff99129 | 2015-09-07 17:12:56 +0200 | [diff] [blame] | 2453 | BDRVQcow2State *s = bs->opaque; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2454 | uint64_t *l1_table = NULL; |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2455 | int64_t l1_entries = 0, visited_l1_entries = 0; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2456 | int ret; |
| 2457 | int i, j; |
| 2458 | |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2459 | if (status_cb) { |
| 2460 | l1_entries = s->l1_size; |
| 2461 | for (i = 0; i < s->nb_snapshots; i++) { |
| 2462 | l1_entries += s->snapshots[i].l1_size; |
| 2463 | } |
| 2464 | } |
| 2465 | |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2466 | ret = expand_zero_clusters_in_l1(bs, s->l1_table, s->l1_size, |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2467 | &visited_l1_entries, l1_entries, |
Max Reitz | 8b13976 | 2015-07-27 17:51:32 +0200 | [diff] [blame] | 2468 | status_cb, cb_opaque); |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2469 | if (ret < 0) { |
| 2470 | goto fail; |
| 2471 | } |
| 2472 | |
| 2473 | /* Inactive L1 tables may point to active L2 tables - therefore it is |
| 2474 | * necessary to flush the L2 table cache before trying to access the L2 |
| 2475 | * tables pointed to by inactive L1 entries (else we might try to expand |
| 2476 | * zero clusters that have already been expanded); furthermore, it is also |
| 2477 | * necessary to empty the L2 table cache, since it may contain tables which |
| 2478 | * are now going to be modified directly on disk, bypassing the cache. |
| 2479 | * qcow2_cache_empty() does both for us. */ |
| 2480 | ret = qcow2_cache_empty(bs, s->l2_table_cache); |
| 2481 | if (ret < 0) { |
| 2482 | goto fail; |
| 2483 | } |
| 2484 | |
| 2485 | for (i = 0; i < s->nb_snapshots; i++) { |
Alberto Garcia | c9a442e | 2018-03-06 18:14:08 +0200 | [diff] [blame] | 2486 | int l1_size2; |
| 2487 | uint64_t *new_l1_table; |
| 2488 | Error *local_err = NULL; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2489 | |
Alberto Garcia | c9a442e | 2018-03-06 18:14:08 +0200 | [diff] [blame] | 2490 | ret = qcow2_validate_table(bs, s->snapshots[i].l1_table_offset, |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 2491 | s->snapshots[i].l1_size, L1E_SIZE, |
Alberto Garcia | c9a442e | 2018-03-06 18:14:08 +0200 | [diff] [blame] | 2492 | QCOW_MAX_L1_SIZE, "Snapshot L1 table", |
| 2493 | &local_err); |
| 2494 | if (ret < 0) { |
| 2495 | error_report_err(local_err); |
| 2496 | goto fail; |
| 2497 | } |
| 2498 | |
Alberto Garcia | 02b1ecf | 2020-08-28 13:08:28 +0200 | [diff] [blame] | 2499 | l1_size2 = s->snapshots[i].l1_size * L1E_SIZE; |
Alberto Garcia | c9a442e | 2018-03-06 18:14:08 +0200 | [diff] [blame] | 2500 | new_l1_table = g_try_realloc(l1_table, l1_size2); |
Alberto Garcia | de7269d | 2018-02-09 16:42:22 +0200 | [diff] [blame] | 2501 | |
| 2502 | if (!new_l1_table) { |
| 2503 | ret = -ENOMEM; |
| 2504 | goto fail; |
| 2505 | } |
| 2506 | |
| 2507 | l1_table = new_l1_table; |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2508 | |
Alberto Faria | 32cc71d | 2022-06-09 16:27:36 +0100 | [diff] [blame] | 2509 | ret = bdrv_pread(bs->file, s->snapshots[i].l1_table_offset, l1_size2, |
| 2510 | l1_table, 0); |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2511 | if (ret < 0) { |
| 2512 | goto fail; |
| 2513 | } |
| 2514 | |
| 2515 | for (j = 0; j < s->snapshots[i].l1_size; j++) { |
| 2516 | be64_to_cpus(&l1_table[j]); |
| 2517 | } |
| 2518 | |
| 2519 | ret = expand_zero_clusters_in_l1(bs, l1_table, s->snapshots[i].l1_size, |
Max Reitz | 4057a2b | 2014-10-27 11:12:53 +0100 | [diff] [blame] | 2520 | &visited_l1_entries, l1_entries, |
Max Reitz | 8b13976 | 2015-07-27 17:51:32 +0200 | [diff] [blame] | 2521 | status_cb, cb_opaque); |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2522 | if (ret < 0) { |
| 2523 | goto fail; |
| 2524 | } |
| 2525 | } |
| 2526 | |
| 2527 | ret = 0; |
| 2528 | |
| 2529 | fail: |
Max Reitz | 32b6444 | 2013-09-03 10:09:52 +0200 | [diff] [blame] | 2530 | g_free(l1_table); |
| 2531 | return ret; |
| 2532 | } |
Vladimir Sementsov-Ogievskiy | a6e0984 | 2021-09-14 15:24:47 +0300 | [diff] [blame] | 2533 | |
| 2534 | void qcow2_parse_compressed_l2_entry(BlockDriverState *bs, uint64_t l2_entry, |
| 2535 | uint64_t *coffset, int *csize) |
| 2536 | { |
| 2537 | BDRVQcow2State *s = bs->opaque; |
| 2538 | int nb_csectors; |
| 2539 | |
| 2540 | assert(qcow2_get_cluster_type(bs, l2_entry) == QCOW2_CLUSTER_COMPRESSED); |
| 2541 | |
| 2542 | *coffset = l2_entry & s->cluster_offset_mask; |
| 2543 | |
| 2544 | nb_csectors = ((l2_entry >> s->csize_shift) & s->csize_mask) + 1; |
| 2545 | *csize = nb_csectors * QCOW2_COMPRESSED_SECTOR_SIZE - |
| 2546 | (*coffset & (QCOW2_COMPRESSED_SECTOR_SIZE - 1)); |
| 2547 | } |