| Message ID | AANLkTimFu_z+HLRw+O2KM9EwJVS7U1DC1Adt4UKZxRjs@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
Blue Swirl <blauwirbel@gmail.com> writes: > Block device change command did not copy BDRV_O_SNAPSHOT flag. Thus > the new image did not have this flag and the file got deleted during > opening. > > Fix by copying BDRV_O_SNAPSHOT flag. Aha: the file gets deleted because bs->is_temporary survives change, but BDRV_O_SNAPSHOT does not. Thus, the new image gets opened without a snapshot file wrapped around it. But since is_temporary is still true, we attempt to delete the (nonexistant) snapshot file, and end up deleting the image file instead. Your fix makes sense. But I recommend to additionally set bs->is_temporary unconditionally in bdrv_open(). Or get rid of it and test bs->open_flags instead.
Am 25.07.2010 22:49, schrieb Blue Swirl: > Block device change command did not copy BDRV_O_SNAPSHOT flag. Thus > the new image did not have this flag and the file got deleted during > opening. > > Fix by copying BDRV_O_SNAPSHOT flag. > > Signed-off-by: Blue Swirl <blauwirbel@gmail.com> Thanks, applied to the block branch. > diff --git a/block.h b/block.h > index c2a7e4c..db131a3 100644 > --- a/block.h > +++ b/block.h > @@ -202,6 +202,7 @@ const char > *bdrv_get_encrypted_filename(BlockDriverState *bs); Please avoid wrapped lines when you send patches, e.g. by using git send-email. Kevin
diff --git a/block.c b/block.c index f837876..14cfed1 100644 --- a/block.c +++ b/block.c @@ -1800,6 +1800,11 @@ int bdrv_can_snapshot(BlockDriverState *bs) return 1; } +int bdrv_is_snapshot(BlockDriverState *bs) +{ + return !!(bs->open_flags & BDRV_O_SNAPSHOT); +} + BlockDriverState *bdrv_snapshots(void) { BlockDriverState *bs; diff --git a/block.h b/block.h index c2a7e4c..db131a3 100644 --- a/block.h +++ b/block.h @@ -202,6 +202,7 @@ const char *bdrv_get_encrypted_filename(BlockDriverState *bs); void bdrv_get_backing_filename(BlockDriverState *bs, char *filename, int filename_size); int bdrv_can_snapshot(BlockDriverState *bs); +int bdrv_is_snapshot(BlockDriverState *bs); BlockDriverState *bdrv_snapshots(void); int bdrv_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); diff --git a/blockdev.c b/blockdev.c index 0a9dec3..01e402b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -590,6 +590,7 @@ int do_change_block(Monitor *mon, const char *device, return -1; } bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR; + bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0; if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) { qerror_report(QERR_OPEN_FILE_FAILED, filename); return -1;
Block device change command did not copy BDRV_O_SNAPSHOT flag. Thus the new image did not have this flag and the file got deleted during opening. Fix by copying BDRV_O_SNAPSHOT flag. Signed-off-by: Blue Swirl <blauwirbel@gmail.com> --- block.c | 5 +++++ block.h | 1 + blockdev.c | 1 + 3 files changed, 7 insertions(+), 0 deletions(-)