linux.git/fs/btrfs/compression.c, branch v6.11

btrfs: fix extent map use-after-free when adding pages to compressed bio

2024-07-11T14:32:22+00:00

At add_ra_bio_pages() we are accessing the extent map to calculate
'add_size' after we dropped our reference on the extent map, resulting
in a use-after-free. Fix this by computing 'add_size' before dropping our
extent map reference.

Reported-by: syzbot+853d80cba98ce1157ae6@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/000000000000038144061c6d18f2@google.com/
Fixes: 6a4049102055 ("btrfs: subpage: make add_ra_bio_pages() compatible")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: remove the extra_gfp parameter from btrfs_alloc_folio_array()

2024-07-11T13:33:30+00:00

The function btrfs_alloc_folio_array() is only utilized in
btrfs_submit_compressed_read() and no other location, and the only
caller is not utilizing the @extra_gfp parameter.

Reviewed-by: Filipe Manana 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: pass a btrfs_inode to btrfs_compress_heuristic()

2024-07-11T13:33:28+00:00

Pass a struct btrfs_inode to btrfs_compress_heuristic() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Boris Burkov 
Signed-off-by: David Sterba

btrfs: switch btrfs_ordered_extent::inode to struct btrfs_inode

2024-07-11T13:33:28+00:00

The structure is internal so we should use struct btrfs_inode for that,
allowing to remove some use of BTRFS_I.

Reviewed-by: Boris Burkov 
Signed-off-by: David Sterba

btrfs: remove extent_map::block_start member

2024-07-11T13:33:21+00:00

The member extent_map::block_start can be calculated from
extent_map::disk_bytenr + extent_map::offset for regular extents.
And otherwise just extent_map::disk_bytenr.

And this is already validated by the validate_extent_map().  Now we can
remove the member.

However there is a special case in btrfs_create_dio_extent() where we
for NOCOW/PREALLOC ordered extents cannot directly use the resulting
btrfs_file_extent, as btrfs_split_ordered_extent() cannot handle them
yet.

So for that call site, we pass file_extent->disk_bytenr +
file_extent->num_bytes as disk_bytenr for the ordered extent, and 0 for
offset.

Reviewed-by: Johannes Thumshirn 
Reviewed-by: Filipe Manana 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: remove extent_map::block_len member

2024-07-11T13:33:20+00:00

The extent_map::block_len is either extent_map::len (non-compressed
extent) or extent_map::disk_num_bytes (compressed extent).

Since we already have sanity checks to do the cross-checks between the
new and old members, we can drop the old extent_map::block_len now.

For most call sites, they can manually select extent_map::len or
extent_map::disk_num_bytes, since most if not all of them have checked
if the extent is compressed.

Reviewed-by: Johannes Thumshirn 
Reviewed-by: Filipe Manana 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: remove extent_map::orig_start member

2024-07-11T13:33:20+00:00

Since we have extent_map::offset, the old extent_map::orig_start is just
extent_map::start - extent_map::offset for non-hole/inline extents.

And since the new extent_map::offset is already verified by
validate_extent_map() while the old orig_start is not, let's just remove
the old member from all call sites.

Reviewed-by: Johannes Thumshirn 
Reviewed-by: Filipe Manana 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: fix misspelled end IO compression callbacks

2024-07-11T13:33:16+00:00

Fix typo in the end IO compression callbacks, from "comprssed" to
"compressed".

Reviewed-by: Qu Wenruo 
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: change root->root_key.objectid to btrfs_root_id()

2024-05-07T19:31:06+00:00

A comment from Filipe on one of my previous cleanups brought my
attention to a new helper we have for getting the root id of a root,
which makes it easier to read in the code.

The changes where made with the following Coccinelle semantic patch:

// 
@@
expression E,E1;
@@
(
 E->root_key.objectid = E1
|
- E->root_key.objectid
+ btrfs_root_id(E)
)
// 

Reviewed-by: Filipe Manana 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
[ minor style fixups ]
Signed-off-by: David Sterba

btrfs: compression: migrate compression/decompression paths to folios

2024-05-07T19:31:02+00:00

For both compression and decompression paths, we always require a
"struct page **pages" and "unsigned long nr_pages", this involves quite
some part of the btrfs compression paths:

- All the compression entry points

- compressed_bio structure
  This affects both compression and decompression.

- async_extent structure

Unfortunately with all those involved parts, there is no good way to
split the conversion into smaller patches while still passing compiling.
So do this in one big conversion in one go.

Please note this is direct page->folio conversion, no change on the page
sized folio requirement yet.

Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
[ minor style fixups ]
Signed-off-by: David Sterba