block: document fields protected by AioContext lock
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-19-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 2d92d7e..1670941 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -430,8 +430,9 @@
* copied as well.
*/
struct BlockDriverState {
- int64_t total_sectors; /* if we are reading a disk image, give its
- size in sectors */
+ /* Protected by big QEMU lock or read-only after opening. No special
+ * locking needed during I/O...
+ */
int open_flags; /* flags used to open the file, re-used for re-open */
bool read_only; /* if true, the media is read only */
bool encrypted; /* if true, the media is encrypted */
@@ -439,14 +440,6 @@
bool sg; /* if true, the device is a /dev/sg* */
bool probed; /* if true, format was probed rather than specified */
- int copy_on_read; /* if nonzero, copy read backing sectors into image.
- note this is a reference count */
-
- CoQueue flush_queue; /* Serializing flush queue */
- bool active_flush_req; /* Flush request in flight? */
- unsigned int write_gen; /* Current data generation */
- unsigned int flushed_gen; /* Flushed write generation */
-
BlockDriver *drv; /* NULL means no media */
void *opaque;
@@ -468,18 +461,6 @@
BdrvChild *backing;
BdrvChild *file;
- /* Callback before write request is processed */
- NotifierWithReturnList before_write_notifiers;
-
- /* number of in-flight requests; overall and serialising */
- unsigned int in_flight;
- unsigned int serialising_in_flight;
-
- bool wakeup;
-
- /* Offset after the highest byte written to */
- uint64_t wr_highest_offset;
-
/* I/O Limits */
BlockLimits bl;
@@ -497,11 +478,8 @@
QTAILQ_ENTRY(BlockDriverState) bs_list;
/* element of the list of monitor-owned BDS */
QTAILQ_ENTRY(BlockDriverState) monitor_list;
- QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
int refcnt;
- QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
-
/* operation blockers */
QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
@@ -522,6 +500,31 @@
/* The error object in use for blocking operations on backing_hd */
Error *backing_blocker;
+ /* Protected by AioContext lock */
+
+ /* If true, copy read backing sectors into image. Can be >1 if more
+ * than one client has requested copy-on-read.
+ */
+ int copy_on_read;
+
+ /* If we are reading a disk image, give its size in sectors.
+ * Generally read-only; it is written to by load_vmstate and save_vmstate,
+ * but the block layer is quiescent during those.
+ */
+ int64_t total_sectors;
+
+ /* Callback before write request is processed */
+ NotifierWithReturnList before_write_notifiers;
+
+ /* number of in-flight requests; overall and serialising */
+ unsigned int in_flight;
+ unsigned int serialising_in_flight;
+
+ bool wakeup;
+
+ /* Offset after the highest byte written to */
+ uint64_t wr_highest_offset;
+
/* threshold limit for writes, in bytes. "High water mark". */
uint64_t write_threshold_offset;
NotifierWithReturn write_threshold_notifier;
@@ -529,6 +532,17 @@
/* counter for nested bdrv_io_plug */
unsigned io_plugged;
+ QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
+ CoQueue flush_queue; /* Serializing flush queue */
+ bool active_flush_req; /* Flush request in flight? */
+ unsigned int write_gen; /* Current data generation */
+ unsigned int flushed_gen; /* Flushed write generation */
+
+ QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
+
+ /* do we need to tell the quest if we have a volatile write cache? */
+ int enable_write_cache;
+
int quiesce_counter;
};
