| Message ID | 20151013180648.GC4890@ret.masoncoding.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Tue, Oct 13, 2015 at 7:06 PM, Chris Mason <clm@fb.com> wrote: > The code for btrfs inode-resolve has never worked properly for > files with enough hard links to trigger extrefs. It was trying to > get the leaf out of a path after freeing the path: > > btrfs_release_path(path); > leaf = path->nodes[0]; > item_size = btrfs_item_size_nr(leaf, slot); > > The fix here is to use the extent buffer we cloned just a little higher > up to avoid deadlocks caused by using the leaf in the path. > > Signed-off-by: Chris Mason <clm@fb.com> > cc: stable@vger.kernel.org # v3.7+ > cc: Mark Fasheh <mfasheh@suse.de> Reviewed-by: Filipe Manana <fdmanana@suse.com> Looks good to me. I failed to notice that problem at commit [1] [1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3fe81ce206f3805e0eb5d886aabbf91064655144 > --- > fs/btrfs/backref.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c > index ecbc63d..9a2ec79 100644 > --- a/fs/btrfs/backref.c > +++ b/fs/btrfs/backref.c > @@ -1828,7 +1828,6 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, > int found = 0; > struct extent_buffer *eb; > struct btrfs_inode_extref *extref; > - struct extent_buffer *leaf; > u32 item_size; > u32 cur_offset; > unsigned long ptr; > @@ -1856,9 +1855,8 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, > btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); > btrfs_release_path(path); > > - leaf = path->nodes[0]; > - item_size = btrfs_item_size_nr(leaf, slot); > - ptr = btrfs_item_ptr_offset(leaf, slot); > + item_size = btrfs_item_size_nr(eb, slot); > + ptr = btrfs_item_ptr_offset(eb, slot); > cur_offset = 0; > > while (cur_offset < item_size) { > @@ -1872,7 +1870,7 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, > if (ret) > break; > > - cur_offset += btrfs_inode_extref_name_len(leaf, extref); > + cur_offset += btrfs_inode_extref_name_len(eb, extref); > cur_offset += sizeof(*extref); > } > btrfs_tree_read_unlock_blocking(eb); > -- > 2.4.6 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 13, 2015 at 02:06:48PM -0400, Chris Mason wrote: > The code for btrfs inode-resolve has never worked properly for > files with enough hard links to trigger extrefs. It was trying to > get the leaf out of a path after freeing the path: > > btrfs_release_path(path); > leaf = path->nodes[0]; > item_size = btrfs_item_size_nr(leaf, slot); > > The fix here is to use the extent buffer we cloned just a little higher > up to avoid deadlocks caused by using the leaf in the path. > > Signed-off-by: Chris Mason <clm@fb.com> > cc: stable@vger.kernel.org # v3.7+ > cc: Mark Fasheh <mfasheh@suse.de> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Thanks for the CC Chris. --Mark -- Mark Fasheh -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 13, 2015 at 12:17:55PM -0700, Mark Fasheh wrote: > On Tue, Oct 13, 2015 at 02:06:48PM -0400, Chris Mason wrote: > > The code for btrfs inode-resolve has never worked properly for > > files with enough hard links to trigger extrefs. It was trying to > > get the leaf out of a path after freeing the path: > > > > btrfs_release_path(path); > > leaf = path->nodes[0]; > > item_size = btrfs_item_size_nr(leaf, slot); > > > > The fix here is to use the extent buffer we cloned just a little higher > > up to avoid deadlocks caused by using the leaf in the path. > > > > Signed-off-by: Chris Mason <clm@fb.com> > > cc: stable@vger.kernel.org # v3.7+ > > cc: Mark Fasheh <mfasheh@suse.de> > Reviewed-by: Mark Fasheh <mfasheh@suse.de> Thanks Mark and Filipe, I've tested this and queued it up. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index ecbc63d..9a2ec79 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -1828,7 +1828,6 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, int found = 0; struct extent_buffer *eb; struct btrfs_inode_extref *extref; - struct extent_buffer *leaf; u32 item_size; u32 cur_offset; unsigned long ptr; @@ -1856,9 +1855,8 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); btrfs_release_path(path); - leaf = path->nodes[0]; - item_size = btrfs_item_size_nr(leaf, slot); - ptr = btrfs_item_ptr_offset(leaf, slot); + item_size = btrfs_item_size_nr(eb, slot); + ptr = btrfs_item_ptr_offset(eb, slot); cur_offset = 0; while (cur_offset < item_size) { @@ -1872,7 +1870,7 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, if (ret) break; - cur_offset += btrfs_inode_extref_name_len(leaf, extref); + cur_offset += btrfs_inode_extref_name_len(eb, extref); cur_offset += sizeof(*extref); } btrfs_tree_read_unlock_blocking(eb);
The code for btrfs inode-resolve has never worked properly for files with enough hard links to trigger extrefs. It was trying to get the leaf out of a path after freeing the path: btrfs_release_path(path); leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, slot); The fix here is to use the extent buffer we cloned just a little higher up to avoid deadlocks caused by using the leaf in the path. Signed-off-by: Chris Mason <clm@fb.com> cc: stable@vger.kernel.org # v3.7+ cc: Mark Fasheh <mfasheh@suse.de> --- fs/btrfs/backref.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)