[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 5/8] qcow2: Return real error in qcow2_snapshot_goto
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 5/8] qcow2: Return real error in qcow2_snapshot_goto |
Date: |
Thu, 17 Nov 2011 16:13:51 +0100 |
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2-snapshot.c | 50 +++++++++++++++++++++++++++++++++++++----------
1 files changed, 39 insertions(+), 11 deletions(-)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 066d56b..9f6647f 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -392,17 +392,32 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char
*snapshot_id)
QCowSnapshot *sn;
int i, snapshot_index;
int cur_l1_bytes, sn_l1_bytes;
+ int ret;
+ /* Search the snapshot */
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
- if (snapshot_index < 0)
+ if (snapshot_index < 0) {
return -ENOENT;
+ }
sn = &s->snapshots[snapshot_index];
- if (qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1)
< 0)
+ /* Decrease refcount of clusters of current L1 table.
+ * FIXME This is too early! */
+ ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset,
+ s->l1_size, -1);
+ if (ret < 0) {
goto fail;
+ }
- if (qcow2_grow_l1_table(bs, sn->l1_size, true) < 0)
+ /*
+ * Make sure that the current L1 table is big enough to contain the whole
+ * L1 table of the snapshot. If the snapshot L1 table is smaller, the
+ * current one must be padded with zeros.
+ */
+ ret = qcow2_grow_l1_table(bs, sn->l1_size, true);
+ if (ret < 0) {
goto fail;
+ }
cur_l1_bytes = s->l1_size * sizeof(uint64_t);
sn_l1_bytes = sn->l1_size * sizeof(uint64_t);
@@ -411,19 +426,31 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char
*snapshot_id)
memset(s->l1_table + sn->l1_size, 0, cur_l1_bytes - sn_l1_bytes);
}
- /* copy the snapshot l1 table to the current l1 table */
- if (bdrv_pread(bs->file, sn->l1_table_offset,
- s->l1_table, sn_l1_bytes) < 0)
+ /*
+ * Copy the snapshot L1 table to the current L1 table.
+ *
+ * Before overwriting the old current L1 table on disk, make sure to
+ * increase all refcounts for the clusters referenced by the new one.
+ */
+ ret = bdrv_pread(bs->file, sn->l1_table_offset, s->l1_table, sn_l1_bytes);
+ if (ret < 0) {
goto fail;
- if (bdrv_pwrite_sync(bs->file, s->l1_table_offset,
- s->l1_table, cur_l1_bytes) < 0)
+ }
+
+ ret = bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, cur_l1_bytes);
+ if (ret < 0) {
goto fail;
+ }
+
for(i = 0;i < s->l1_size; i++) {
be64_to_cpus(&s->l1_table[i]);
}
- if (qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1)
< 0)
+ /* FIXME This is too late! */
+ ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size,
1);
+ if (ret < 0) {
goto fail;
+ }
#ifdef DEBUG_ALLOC
{
@@ -432,8 +459,9 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char
*snapshot_id)
}
#endif
return 0;
- fail:
- return -EIO;
+
+fail:
+ return ret;
}
int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
--
1.7.6.4
- [Qemu-devel] [PATCH 3/8] qcow2: Cleanups and memleak fix in qcow2_snapshot_create, (continued)
- [Qemu-devel] [PATCH 3/8] qcow2: Cleanups and memleak fix in qcow2_snapshot_create, Kevin Wolf, 2011/11/17
- [Qemu-devel] [PATCH 7/8] qcow2: Fix order in qcow2_snapshot_delete, Kevin Wolf, 2011/11/17
- [Qemu-devel] [PATCH 6/8] qcow2: Fix order of refcount updates in qcow2_snapshot_goto, Kevin Wolf, 2011/11/17
- [Qemu-devel] [PATCH 2/8] qcow2: Return real error code in qcow2_write_snapshots, Kevin Wolf, 2011/11/17
- [Qemu-devel] [PATCH 8/8] qcow2: Fix error path in qcow2_snapshot_load_tmp, Kevin Wolf, 2011/11/17
- [Qemu-devel] [PATCH 5/8] qcow2: Return real error in qcow2_snapshot_goto,
Kevin Wolf <=
- Re: [Qemu-devel] [PATCH 0/8] qcow2: Fix error paths for internal snapshots, Stefan Hajnoczi, 2011/11/18