linux-stable.git/fs/btrfs/backref.c, branch linux-4.2.y

btrfs: fix use after free iterating extrefs

2015-10-27T00:53:38+00:00

commit dc6c5fb3b514221f2e9d21ee626a9d95d3418dff upstream.

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 
cc: Mark Fasheh 
Reviewed-by: Filipe Manana 
Reviewed-by: Mark Fasheh 
Signed-off-by: Greg Kroah-Hartman

btrfs: backref: Add special time_seq == (u64)-1 case for

2015-06-10T16:25:45+00:00

btrfs_find_all_roots().

Allow btrfs_find_all_roots() to skip all delayed_ref_head lock and tree
lock to do tree search.

This is important for later qgroup implement which will call
find_all_roots() after fs trees are committed.

Signed-off-by: Qu Wenruo 
Signed-off-by: Chris Mason

btrfs: delayed-ref: Use list to replace the ref_root in ref_head.

2015-06-10T16:25:03+00:00

This patch replace the rbtree used in ref_head to list.
This has the following advantage:
1) Easier merge logic.
With the new list implement, we only need to care merging the tail
ref_node with the new ref_node.
And this can be done quite easy at insert time, no need to do a
indicated merge at run_delayed_refs().

Signed-off-by: Qu Wenruo 
Signed-off-by: Chris Mason

btrfs: backref: Don't merge refs which are not for same block.

2015-06-10T16:24:59+00:00

Old __merge_refs() in backref.c will even merge refs whose root_id are
different, which makes qgroup gives wrong result.

Fix it by checking ref_for_same_block() before any mode specific works.

Signed-off-by: Qu Wenruo 
Signed-off-by: Chris Mason

Btrfs: fix up read_tree_block to return proper error

2015-06-03T11:03:08+00:00

The return value of read_tree_block() can confuse callers as it always
returns NULL for either -ENOMEM or -EIO, so it's likely that callers
parse it to a wrong error, for instance, in btrfs_read_tree_root().

This fixes the above issue.

Signed-off-by: Liu Bo 
Reviewed-by: David Sterba 
Signed-off-by: Chris Mason

btrfs: clear 'ret' in btrfs_check_shared() loop

2015-05-20T01:04:17+00:00

btrfs_check_shared() is leaking a return value of '1' from
find_parent_nodes(). As a result, callers (in this case, extent_fiemap())
are told extents are shared when they are not. This in turn broke fiemap on
btrfs for kernels v3.18 and up.

The fix is simple - we just have to clear 'ret' after we are done processing
the results of find_parent_nodes().

It wasn't clear to me at first what was happening with return values in
btrfs_check_shared() and find_parent_nodes() - thanks to Josef for the help
on irc. I added documentation to both functions to make things more clear
for the next hacker who might come across them.

If we could queue this up for -stable too that would be great.

Signed-off-by: Mark Fasheh 
Reviewed-by: Josef Bacik 
Signed-off-by: Chris Mason

btrfs: use explicit initializer for seq_elem

2015-03-03T16:23:59+00:00

Using {} as initializer for struct seq_elem does not properly initialize
the list_head member, but it currently works because it gets set through
btrfs_get_tree_mod_seq if 'seq' is 0.

Signed-off-by: David Sterba

btrfs: cleanup, remove inode_ref_info helper

2015-01-14T18:23:47+00:00

A simple wrapper around btrfs_find_item.

Signed-off-by: David Sterba

btrfs: cleanup, remove inode_item_info helper

2015-01-14T18:23:47+00:00

It's only a simple wrapper around btrfs_find_item, the locally defined
key is not used.

Signed-off-by: David Sterba

Btrfs: correctly get tree level in tree_backref_for_extent

2015-01-02T19:47:56+00:00

If we are using skinny metadata, the block's tree level is in the offset
of the key and not in a btrfs_tree_block_info structure following the
extent item (it doesn't exist). Therefore fix it.

Besides returning the correct level in the tree, this also prevents reading
past the leaf's end in the case where the extent item is the last item in
the leaf (eb) and it has only 1 inline reference - this is because
sizeof(struct btrfs_tree_block_info) is greater than
sizeof(struct btrfs_extent_inline_ref).

Got it while running a scrub which produced the following warning:

    BTRFS: checksum error at logical 42123264 on dev /dev/sde, sector 15840: metadata node (level 24) in tree 5

Signed-off-by: Filipe Manana 
Reviewed-by: Satoru Takeuchi 
Signed-off-by: Chris Mason