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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2019-03-29 14:04:54 +0300
committerKevin Wolf <kwolf@redhat.com>2019-04-02 12:04:44 +0200
commit696aaaed579ac5bf5fa336216909b46d3d8f07a8 (patch)
treebf03fcd6298502f38562377cfb1a2ec1cfbdf1fa /block/file-posix.c
parent38e694fcc918f0f4ac1500a5c92acfa421a69773 (diff)
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block/file-posix: do not fail on unlock bytes
bdrv_replace_child() calls bdrv_check_perm() with error_abort on loosening permissions. However file-locking operations may fail even in this case, for example on NFS. And this leads to Qemu crash. Let's avoid such errors. Note, that we ignore such things anyway on permission update commit and abort. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/file-posix.c')
-rw-r--r--block/file-posix.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/block/file-posix.c b/block/file-posix.c
index db4cccb..1cf4ee4 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -815,6 +815,18 @@ static int raw_handle_perm_lock(BlockDriverState *bs,
switch (op) {
case RAW_PL_PREPARE:
+ if ((s->perm | new_perm) == s->perm &&
+ (s->shared_perm & new_shared) == s->shared_perm)
+ {
+ /*
+ * We are going to unlock bytes, it should not fail. If it fail due
+ * to some fs-dependent permission-unrelated reasons (which occurs
+ * sometimes on NFS and leads to abort in bdrv_replace_child) we
+ * can't prevent such errors by any check here. And we ignore them
+ * anyway in ABORT and COMMIT.
+ */
+ return 0;
+ }
ret = raw_apply_lock_bytes(s, s->fd, s->perm | new_perm,
~s->shared_perm | ~new_shared,
false, errp);