block: Make blk_{pread,pwrite}() return 0 on success
They currently return the value of their 'bytes' parameter on success.
Make them return 0 instead, for consistency with other I/O functions and
in preparation to implement them using generated_co_wrapper. This also
makes it clear that short reads/writes are not possible.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-Id: <20220705161527.1054072-2-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
diff --git a/block.c b/block.c
index 2c00ddd..0fd830e 100644
--- a/block.c
+++ b/block.c
@@ -1045,14 +1045,16 @@
return ret;
}
- drv = bdrv_probe_all(buf, ret, filename);
+ drv = bdrv_probe_all(buf, sizeof(buf), filename);
if (!drv) {
error_setg(errp, "Could not determine image format: No compatible "
"driver found");
- ret = -ENOENT;
+ *pdrv = NULL;
+ return -ENOENT;
}
+
*pdrv = drv;
- return ret;
+ return 0;
}
/**
diff --git a/block/block-backend.c b/block/block-backend.c
index f425b00..4c5e130 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1573,19 +1573,16 @@
ret = blk_do_preadv(blk, offset, bytes, &qiov, 0);
blk_dec_in_flight(blk);
- return ret < 0 ? ret : bytes;
+ return ret;
}
int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
BdrvRequestFlags flags)
{
- int ret;
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
IO_OR_GS_CODE();
- ret = blk_pwritev_part(blk, offset, bytes, &qiov, 0, flags);
-
- return ret < 0 ? ret : bytes;
+ return blk_pwritev_part(blk, offset, bytes, &qiov, 0, flags);
}
int64_t blk_getlength(BlockBackend *blk)
diff --git a/block/qcow.c b/block/qcow.c
index c646d6b..25a4335 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -891,14 +891,14 @@
/* write all the data */
ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header), 0);
- if (ret != sizeof(header)) {
+ if (ret < 0) {
goto exit;
}
if (qcow_opts->has_backing_file) {
ret = blk_pwrite(qcow_blk, sizeof(header),
qcow_opts->backing_file, backing_filename_len, 0);
- if (ret != backing_filename_len) {
+ if (ret < 0) {
goto exit;
}
}
@@ -908,7 +908,7 @@
i++) {
ret = blk_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i,
tmp, BDRV_SECTOR_SIZE, 0);
- if (ret != BDRV_SECTOR_SIZE) {
+ if (ret < 0) {
g_free(tmp);
goto exit;
}
diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
index 3045dda..7551343 100644
--- a/hw/block/m25p80.c
+++ b/hw/block/m25p80.c
@@ -1532,7 +1532,7 @@
trace_m25p80_binding(s);
s->storage = blk_blockalign(s->blk, s->size);
- if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) {
+ if (blk_pread(s->blk, 0, s->storage, s->size) < 0) {
error_setg(errp, "failed to read the initial flash content");
return;
}
diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c
index 525e38c..c32325d 100644
--- a/hw/misc/mac_via.c
+++ b/hw/misc/mac_via.c
@@ -1029,8 +1029,8 @@
return;
}
- len = blk_pread(v1s->blk, 0, v1s->PRAM, sizeof(v1s->PRAM));
- if (len != sizeof(v1s->PRAM)) {
+ ret = blk_pread(v1s->blk, 0, v1s->PRAM, sizeof(v1s->PRAM));
+ if (ret < 0) {
error_setg(errp, "can't read PRAM contents");
return;
}
diff --git a/hw/misc/sifive_u_otp.c b/hw/misc/sifive_u_otp.c
index 6d5f84e..535acde 100644
--- a/hw/misc/sifive_u_otp.c
+++ b/hw/misc/sifive_u_otp.c
@@ -240,7 +240,7 @@
return;
}
- if (blk_pread(s->blk, 0, s->fuse, filesize) != filesize) {
+ if (blk_pread(s->blk, 0, s->fuse, filesize) < 0) {
error_setg(errp, "failed to read the initial flash content");
return;
}
diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c
index d695f6a..8fd9f97 100644
--- a/hw/nvram/eeprom_at24c.c
+++ b/hw/nvram/eeprom_at24c.c
@@ -64,8 +64,8 @@
case I2C_START_RECV:
DPRINTK("clear\n");
if (ee->blk && ee->changed) {
- int len = blk_pwrite(ee->blk, 0, ee->mem, ee->rsize, 0);
- if (len != ee->rsize) {
+ int ret = blk_pwrite(ee->blk, 0, ee->mem, ee->rsize, 0);
+ if (ret < 0) {
ERR(TYPE_AT24C_EE
" : failed to write backing file\n");
}
@@ -165,9 +165,9 @@
memset(ee->mem, 0, ee->rsize);
if (ee->blk) {
- int len = blk_pread(ee->blk, 0, ee->mem, ee->rsize);
+ int ret = blk_pread(ee->blk, 0, ee->mem, ee->rsize);
- if (len != ee->rsize) {
+ if (ret < 0) {
ERR(TYPE_AT24C_EE
" : Failed initial sync with backing file\n");
}
diff --git a/hw/nvram/spapr_nvram.c b/hw/nvram/spapr_nvram.c
index 18b43be..59d2e7b 100644
--- a/hw/nvram/spapr_nvram.c
+++ b/hw/nvram/spapr_nvram.c
@@ -103,7 +103,7 @@
{
SpaprNvram *nvram = spapr->nvram;
hwaddr offset, buffer, len;
- int alen;
+ int ret;
void *membuf;
if ((nargs != 3) || (nret != 2)) {
@@ -128,9 +128,9 @@
membuf = cpu_physical_memory_map(buffer, &len, false);
- alen = len;
+ ret = 0;
if (nvram->blk) {
- alen = blk_pwrite(nvram->blk, offset, membuf, len, 0);
+ ret = blk_pwrite(nvram->blk, offset, membuf, len, 0);
}
assert(nvram->buf);
@@ -138,8 +138,8 @@
cpu_physical_memory_unmap(membuf, len, 0, len);
- rtas_st(rets, 0, (alen < len) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS);
- rtas_st(rets, 1, (alen < 0) ? 0 : alen);
+ rtas_st(rets, 0, (ret < 0) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS);
+ rtas_st(rets, 1, (ret < 0) ? 0 : len);
}
static void spapr_nvram_realize(SpaprVioDevice *dev, Error **errp)
@@ -179,9 +179,9 @@
}
if (nvram->blk) {
- int alen = blk_pread(nvram->blk, 0, nvram->buf, nvram->size);
+ ret = blk_pread(nvram->blk, 0, nvram->buf, nvram->size);
- if (alen != nvram->size) {
+ if (ret < 0) {
error_setg(errp, "can't read spapr-nvram contents");
return;
}
diff --git a/hw/ppc/pnv_pnor.c b/hw/ppc/pnv_pnor.c
index 83ecccc..1fb748a 100644
--- a/hw/ppc/pnv_pnor.c
+++ b/hw/ppc/pnv_pnor.c
@@ -99,7 +99,7 @@
s->storage = blk_blockalign(s->blk, s->size);
- if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) {
+ if (blk_pread(s->blk, 0, s->storage, s->size) < 0) {
error_setg(errp, "failed to read the initial flash content");
return;
}
diff --git a/qemu-img.c b/qemu-img.c
index 4cf4d24..2dc07e5 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -5120,30 +5120,23 @@
in.buf = g_new(uint8_t, in.bsz);
for (out_pos = 0; in_pos < size; block_count++) {
- int in_ret, out_ret;
+ int bytes = (in_pos + in.bsz > size) ? size - in_pos : in.bsz;
- if (in_pos + in.bsz > size) {
- in_ret = blk_pread(blk1, in_pos, in.buf, size - in_pos);
- } else {
- in_ret = blk_pread(blk1, in_pos, in.buf, in.bsz);
- }
- if (in_ret < 0) {
+ ret = blk_pread(blk1, in_pos, in.buf, bytes);
+ if (ret < 0) {
error_report("error while reading from input image file: %s",
- strerror(-in_ret));
- ret = -1;
+ strerror(-ret));
goto out;
}
- in_pos += in_ret;
+ in_pos += bytes;
- out_ret = blk_pwrite(blk2, out_pos, in.buf, in_ret, 0);
-
- if (out_ret < 0) {
+ ret = blk_pwrite(blk2, out_pos, in.buf, bytes, 0);
+ if (ret < 0) {
error_report("error while writing to output image file: %s",
- strerror(-out_ret));
- ret = -1;
+ strerror(-ret));
goto out;
}
- out_pos += out_ret;
+ out_pos += bytes;
}
out:
diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 2f0d8ac..443f22c 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -541,28 +541,34 @@
static int do_pread(BlockBackend *blk, char *buf, int64_t offset,
int64_t bytes, int64_t *total)
{
+ int ret;
+
if (bytes > INT_MAX) {
return -ERANGE;
}
- *total = blk_pread(blk, offset, (uint8_t *)buf, bytes);
- if (*total < 0) {
- return *total;
+ ret = blk_pread(blk, offset, (uint8_t *)buf, bytes);
+ if (ret < 0) {
+ return ret;
}
+ *total = bytes;
return 1;
}
static int do_pwrite(BlockBackend *blk, char *buf, int64_t offset,
int64_t bytes, int flags, int64_t *total)
{
+ int ret;
+
if (bytes > INT_MAX) {
return -ERANGE;
}
- *total = blk_pwrite(blk, offset, (uint8_t *)buf, bytes, flags);
- if (*total < 0) {
- return *total;
+ ret = blk_pwrite(blk, offset, (uint8_t *)buf, bytes, flags);
+ if (ret < 0) {
+ return ret;
}
+ *total = bytes;
return 1;
}
diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c
index a5c163a..3c1a3f6 100644
--- a/tests/unit/test-block-iothread.c
+++ b/tests/unit/test-block-iothread.c
@@ -117,7 +117,7 @@
/* Success */
ret = blk_pread(blk, 0, buf, sizeof(buf));
- g_assert_cmpint(ret, ==, 512);
+ g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_pread(blk, -2, buf, sizeof(buf));
@@ -131,7 +131,7 @@
/* Success */
ret = blk_pwrite(blk, 0, buf, sizeof(buf), 0);
- g_assert_cmpint(ret, ==, 512);
+ g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_pwrite(blk, -2, buf, sizeof(buf), 0);
