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[Qemu-devel] [PATCH v2 9/9] qcow2: Fix error path in qcow2_snapshot_load
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH v2 9/9] qcow2: Fix error path in qcow2_snapshot_load_tmp |
Date: |
Fri, 18 Nov 2011 19:29:05 +0100 |
If the bdrv_read() of the snapshot's L1 table fails, return the right
error code and make sure that the old L1 table is still loaded and we
don't break the BlockDriverState completely.
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2-snapshot.c | 34 ++++++++++++++++++++++------------
1 files changed, 22 insertions(+), 12 deletions(-)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index d4fbcb9..b2d1a56 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -573,32 +573,42 @@ int qcow2_snapshot_list(BlockDriverState *bs,
QEMUSnapshotInfo **psn_tab)
int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name)
{
- int i, snapshot_index, l1_size2;
+ int i, snapshot_index;
BDRVQcowState *s = bs->opaque;
QCowSnapshot *sn;
+ uint64_t *new_l1_table;
+ int new_l1_bytes;
+ int ret;
+ assert(bs->read_only);
+
+ /* Search the snapshot */
snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_name);
if (snapshot_index < 0) {
return -ENOENT;
}
-
sn = &s->snapshots[snapshot_index];
- s->l1_size = sn->l1_size;
- l1_size2 = s->l1_size * sizeof(uint64_t);
- if (s->l1_table != NULL) {
- g_free(s->l1_table);
- }
- s->l1_table_offset = sn->l1_table_offset;
- s->l1_table = g_malloc0(align_offset(l1_size2, 512));
+ /* Allocate and read in the snapshot's L1 table */
+ new_l1_bytes = s->l1_size * sizeof(uint64_t);
+ new_l1_table = g_malloc0(align_offset(new_l1_bytes, 512));
- if (bdrv_pread(bs->file, sn->l1_table_offset,
- s->l1_table, l1_size2) != l1_size2) {
- return -1;
+ ret = bdrv_pread(bs->file, sn->l1_table_offset, new_l1_table,
new_l1_bytes);
+ if (ret < 0) {
+ g_free(new_l1_table);
+ return ret;
}
+ /* Switch the L1 table */
+ g_free(s->l1_table);
+
+ s->l1_size = sn->l1_size;
+ s->l1_table_offset = sn->l1_table_offset;
+ s->l1_table = new_l1_table;
+
for(i = 0;i < s->l1_size; i++) {
be64_to_cpus(&s->l1_table[i]);
}
+
return 0;
}
--
1.7.6.4
- [Qemu-devel] [PATCH v2 3/9] qcow2: Update snapshot table information at once, (continued)
- [Qemu-devel] [PATCH v2 4/9] qcow2: Cleanups and memleak fix in qcow2_snapshot_create, Kevin Wolf, 2011/11/18
- [Qemu-devel] [PATCH v2 2/9] qcow2: Return real error code in qcow2_write_snapshots, Kevin Wolf, 2011/11/18
- [Qemu-devel] [PATCH v2 8/9] qcow2: Fix order in qcow2_snapshot_delete, Kevin Wolf, 2011/11/18
- [Qemu-devel] [PATCH v2 7/9] qcow2: Fix order of refcount updates in qcow2_snapshot_goto, Kevin Wolf, 2011/11/18
- [Qemu-devel] [PATCH v2 9/9] qcow2: Fix error path in qcow2_snapshot_load_tmp,
Kevin Wolf <=
- [Qemu-devel] [PATCH v2 6/9] qcow2: Return real error in qcow2_snapshot_goto, Kevin Wolf, 2011/11/18
- Re: [Qemu-devel] [PATCH v2 0/9] qcow2: Fix error paths for internal snapshots, Stefan Hajnoczi, 2011/11/21