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[Qemu-devel] [PULL 61/93] block: resize backing file image during offlin
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 61/93] block: resize backing file image during offline commit, if necessary |
Date: |
Fri, 24 Jan 2014 18:21:44 +0100 |
From: Jeff Cody <address@hidden>
Currently, if an image file is logically larger than its backing file,
committing it via 'qemu-img commit' will fail.
For instance, if we have a base image with a virtual size 10G, and a
snapshot image of size 20G, then committing the snapshot offline with
'qemu-img commit' will likely fail.
This will automatically attempt to resize the base image, if the
snapshot image to be committed is larger.
Signed-off-by: Jeff Cody <address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Benoit Canet <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/block.c b/block.c
index 18c0a8d..72bccb1 100644
--- a/block.c
+++ b/block.c
@@ -2030,10 +2030,10 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult
*res, BdrvCheckMode fix)
int bdrv_commit(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
- int64_t sector, total_sectors;
+ int64_t sector, total_sectors, length, backing_length;
int n, ro, open_flags;
int ret = 0;
- uint8_t *buf;
+ uint8_t *buf = NULL;
char filename[PATH_MAX];
if (!drv)
@@ -2058,7 +2058,29 @@ int bdrv_commit(BlockDriverState *bs)
}
}
- total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
+ length = bdrv_getlength(bs);
+ if (length < 0) {
+ ret = length;
+ goto ro_cleanup;
+ }
+
+ backing_length = bdrv_getlength(bs->backing_hd);
+ if (backing_length < 0) {
+ ret = backing_length;
+ goto ro_cleanup;
+ }
+
+ /* If our top snapshot is larger than the backing file image,
+ * grow the backing file image if possible. If not possible,
+ * we must return an error */
+ if (length > backing_length) {
+ ret = bdrv_truncate(bs->backing_hd, length);
+ if (ret < 0) {
+ goto ro_cleanup;
+ }
+ }
+
+ total_sectors = length >> BDRV_SECTOR_BITS;
buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
for (sector = 0; sector < total_sectors; sector += n) {
--
1.8.1.4
- [Qemu-devel] [PULL 45/93] vmdk: Check for overhead when opening, (continued)
- [Qemu-devel] [PULL 45/93] vmdk: Check for overhead when opening, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 46/93] qemu-progress: Drop unused include, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 47/93] qemu-progress: Fix progress printing on SIGUSR1, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 49/93] sheepdog: fix 'qemu-img map', Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 48/93] Documentation: qemu-img: Mention SIGUSR1 progress report, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 51/93] vmdk: Fix format specific information (create type) for streamOptimized, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 50/93] drive mirror:fix memory leak, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 52/93] qapi: Add "backing" to BlockStats, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 54/93] block: Allow the user to define "node-name" option both on command line and QMP., Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 53/93] block: Add bs->node_name to hold the name of a bs node of the bs graph., Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 61/93] block: resize backing file image during offline commit, if necessary,
Kevin Wolf <=
- [Qemu-devel] [PULL 62/93] block: resize backing image during active layer commit, if needed, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 64/93] block: Fix bdrv_commit return value, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 63/93] block: update block commit documentation regarding image truncation, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 65/93] block: Move initialisation of BlockLimits to bdrv_refresh_limits(), Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 66/93] block: Inherit opt_transfer_length, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 68/93] qemu_memalign: Allow small alignments, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 67/93] block: Update BlockLimits when they might have changed, Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 69/93] block: Detect unaligned length in bdrv_qiov_is_aligned(), Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 70/93] block: Don't use guest sector size for qemu_blockalign(), Kevin Wolf, 2014/01/24
- [Qemu-devel] [PULL 71/93] block: rename buffer_alignment to guest_block_size, Kevin Wolf, 2014/01/24