Another wave of defence enhancment, including:
- Enhanced eb accessors
Not really needed for the fuzzed images, as 448de471cd4c
("btrfs: Check the first key and level for cached extent buffer")
already fixed half of the reported images.
Just add a final layer of safe net.
- BUG_ON() hunt in __btrfs_free_extent()
Kill BUG_ON()s in __btrfs_free_extent(), replace with error reporting
and why it shouldn't happen.
Also add comment on what __btrfs_free_extent() is designed to do, with
two dump-tree examples for newcomers.
- BUG_ON() hunt in __btrfs_inc_extent_ref()
Just like __btrfs_free_extent(), but less comment as
comment for __btrfs_free_extent() should also work for
__btrfs_inc_extent_ref(), and __btrfs_inc_extent_ref() has a better
structure than __btrfs_free_extent().
- Defence against unbalanced empty leaf
- Defence against bad key order across two tree blocks
The last two cases can't be rejected by tree-checker and they are all
cross-eb cases.
Thankfully we can reuse existing first_key check against unbalanced
empty leaf, but needs extra check deep into ctree.c for tree block
merging time check.
Reported-by: Jungyeon Yoon <jungyeon.y...@gmail.com>
[ Not to mail bombarding the report, thus only RB tag in cover letter ]
Qu Wenruo (5):
btrfs: extent_io: Do extra check for extent buffer read write
functions
btrfs: extent-tree: Kill BUG_ON() in __btrfs_free_extent() and do
better comment
btrfs: Detect unbalanced tree with empty leaf before crashing btree
operations
btrfs: extent-tree: Kill the BUG_ON() in
insert_inline_extent_backref()
btrfs: ctree: Checking key orders before merged tree blocks
fs/btrfs/ctree.c | 63 +++++++++++++++
fs/btrfs/disk-io.c | 9 +++
fs/btrfs/extent-tree.c | 168 ++++++++++++++++++++++++++++++++++++----
fs/btrfs/extent_io.c | 79 ++++++++++---------
fs/btrfs/tree-checker.c | 6 ++
5 files changed, 273 insertions(+), 52 deletions(-)
--
2.22.0
