motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-02 07:13:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

block: let commit blockjob run in BDS AioContext

Browse source 
The commit block job must run in the BlockDriverState AioContext so that
it works with dataplane.

Acquire the AioContext in blockdev.c so starting the block job is safe.
One detail here is that the bdrv_drain_all() must be moved inside the
aio_context_acquire() region so requests cannot sneak in between the
drain and acquire.

The completion code in block/commit.c must perform backing chain
manipulation and bdrv_reopen() from the main loop.  Use
block_job_defer_to_main_loop() to achieve that.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1413889440-32577-11-git-send-email-stefanha@redhat.com
This commit is contained in:
Stefan Hajnoczi 2014-10-21 12:03:59 +01:00
parent 5a7e7a0bad
commit 9e85cd5ce0
2 changed files with 64 additions and 35 deletions
Download patch file Download diff file Expand all files Collapse all files

70
block/commit.c
View file

@ -60,17 +60,50 @@ static int coroutine_fn commit_populate(BlockDriverState *bs,
return 0;
}
static void coroutine_fn commit_run(void *opaque)
typedef struct {
int ret;
} CommitCompleteData;
static void commit_complete(BlockJob *job, void *opaque)
{
CommitBlockJob *s = opaque;
CommitBlockJob *s = container_of(job, CommitBlockJob, common);
CommitCompleteData *data = opaque;
BlockDriverState *active = s->active;
BlockDriverState *top = s->top;
BlockDriverState *base = s->base;
BlockDriverState *overlay_bs;
int ret = data->ret;
if (!block_job_is_cancelled(&s->common) && ret == 0) {
/* success */
ret = bdrv_drop_intermediate(active, top, base, s->backing_file_str);
}
/* restore base open flags here if appropriate (e.g., change the base back
* to r/o). These reopens do not need to be atomic, since we won't abort
* even on failure here */
if (s->base_flags != bdrv_get_flags(base)) {
bdrv_reopen(base, s->base_flags, NULL);
}
overlay_bs = bdrv_find_overlay(active, top);
if (overlay_bs && s->orig_overlay_flags != bdrv_get_flags(overlay_bs)) {
bdrv_reopen(overlay_bs, s->orig_overlay_flags, NULL);
}
g_free(s->backing_file_str);
block_job_completed(&s->common, ret);
g_free(data);
}
static void coroutine_fn commit_run(void *opaque)
{
CommitBlockJob *s = opaque;
CommitCompleteData *data;
BlockDriverState *top = s->top;
BlockDriverState *base = s->base;
int64_t sector_num, end;
int ret = 0;
int n = 0;
void *buf;
void *buf = NULL;
int bytes_written = 0;
int64_t base_len;
@ -78,18 +111,18 @@ static void coroutine_fn commit_run(void *opaque)
if (s->common.len < 0) {
goto exit_restore_reopen;
goto out;
}
ret = base_len = bdrv_getlength(base);
if (base_len < 0) {
goto exit_restore_reopen;
goto out;
}
if (base_len < s->common.len) {
ret = bdrv_truncate(base, s->common.len);
if (ret) {
goto exit_restore_reopen;
goto out;
}
}
@ -128,7 +161,7 @@ wait:
if (s->on_error == BLOCKDEV_ON_ERROR_STOP ||
s->on_error == BLOCKDEV_ON_ERROR_REPORT||
(s->on_error == BLOCKDEV_ON_ERROR_ENOSPC && ret == -ENOSPC)) {
goto exit_free_buf;
goto out;
} else {
n = 0;
continue;
@ -140,27 +173,12 @@ wait:
ret = 0;
if (!block_job_is_cancelled(&s->common) && sector_num == end) {
/* success */
ret = bdrv_drop_intermediate(active, top, base, s->backing_file_str);
}
exit_free_buf:
out:
qemu_vfree(buf);
exit_restore_reopen:
/* restore base open flags here if appropriate (e.g., change the base back
* to r/o). These reopens do not need to be atomic, since we won't abort
* even on failure here */
if (s->base_flags != bdrv_get_flags(base)) {
bdrv_reopen(base, s->base_flags, NULL);
}
overlay_bs = bdrv_find_overlay(active, top);
if (overlay_bs && s->orig_overlay_flags != bdrv_get_flags(overlay_bs)) {
bdrv_reopen(overlay_bs, s->orig_overlay_flags, NULL);
}
g_free(s->backing_file_str);
block_job_completed(&s->common, ret);
data = g_malloc(sizeof(*data));
data->ret = ret;
block_job_defer_to_main_loop(&s->common, commit_complete, data);
}
static void commit_set_speed(BlockJob *job, int64_t speed, Error **errp)