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| author | Filipe Manana <fdmanana@suse.com> | 2015-03-02 23:53:53 +0300 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2015-03-27 03:55:51 +0300 |
| commit | 2f1f465ae6da244099af55c066e5355abd8ff620 (patch) | |
| tree | 05e245ff3ad099a59616f39710737119cb0442df /fs/btrfs/send.c | |
| parent | 5cc2b17e80cf5770f2e585c2d90fd8af1b901258 (diff) | |
| download | linux-2f1f465ae6da244099af55c066e5355abd8ff620.tar.xz | |
Btrfs: send, don't leave without decrementing clone root's send_progress
If the clone root was not readonly or the dead flag was set on it, we were
leaving without decrementing the root's send_progress counter (and before
we just incremented it). If a concurrent snapshot deletion was in progress
and ended up being aborted, it would be impossible to later attempt to
delete again the snapshot, since the root's send_in_progress counter could
never go back to 0.
We were also setting clone_sources_to_rollback to i + 1 too early - if we
bailed out because the clone root we got is not readonly or flagged as dead
we ended up later derreferencing a null pointer because we didn't assign
the clone root to sctx->clone_roots[i].root:
for (i = 0; sctx && i < clone_sources_to_rollback; i++)
btrfs_root_dec_send_in_progress(
sctx->clone_roots[i].root);
So just don't increment the send_in_progress counter if the root is readonly
or flagged as dead.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/send.c')
| -rw-r--r-- | fs/btrfs/send.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 6ec28f13659e..571de5a08fe7 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -5852,9 +5852,7 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_) ret = PTR_ERR(clone_root); goto out; } - clone_sources_to_rollback = i + 1; spin_lock(&clone_root->root_item_lock); - clone_root->send_in_progress++; if (!btrfs_root_readonly(clone_root) || btrfs_root_dead(clone_root)) { spin_unlock(&clone_root->root_item_lock); @@ -5862,10 +5860,12 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_) ret = -EPERM; goto out; } + clone_root->send_in_progress++; spin_unlock(&clone_root->root_item_lock); srcu_read_unlock(&fs_info->subvol_srcu, index); sctx->clone_roots[i].root = clone_root; + clone_sources_to_rollback = i + 1; } vfree(clone_sources_tmp); clone_sources_tmp = NULL; |