diff options
| author | Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | 2011-11-17 13:40:27 +0000 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2011-12-05 14:51:38 +0100 |
| commit | dbffbdcfff69431b622866ac5ea78df74fdc02d4 (patch) | |
| tree | ec4b73f7c58efde89080cf37588ed9ce56fe3b55 /block_int.h | |
| parent | e8ee5e4c476d5b0654d8f1271a2b7c065acc486e (diff) | |
block: add request tracking
The block layer does not know about pending requests. This information
is necessary for copy-on-read since overlapping requests must be
serialized to prevent races that corrupt the image.
The BlockDriverState gets a new tracked_request list field which
contains all pending requests. Each request is a BdrvTrackedRequest
record with sector_num, nb_sectors, and is_write fields.
Note that request tracking is always enabled but hopefully this extra
work is so small that it doesn't justify adding an enable/disable flag.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block_int.h')
| -rw-r--r-- | block_int.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/block_int.h b/block_int.h index a0b46d71d1..ea818e4e71 100644 --- a/block_int.h +++ b/block_int.h @@ -51,6 +51,8 @@ #define BLOCK_OPT_PREALLOC "preallocation" #define BLOCK_OPT_SUBFMT "subformat" +typedef struct BdrvTrackedRequest BdrvTrackedRequest; + typedef struct AIOPool { void (*cancel)(BlockDriverAIOCB *acb); int aiocb_size; @@ -255,6 +257,8 @@ struct BlockDriverState { int in_use; /* users other than guest access, eg. block migration */ QTAILQ_ENTRY(BlockDriverState) list; void *private; + + QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; }; struct BlockDriverAIOCB { |