linux.git/fs/btrfs/compression.c, branch v6.12

btrfs: convert btrfs_decompress() to take a folio

2024-09-10T14:51:21+00:00

The old page API is being gradually replaced and converted to use folio
to improve code readability and avoid repeated conversion between page
and folio. Based on the previous patch, the compression path can be
directly used in folio without converting to page.

Signed-off-by: Li Zetao 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: convert zstd_decompress() to take a folio

2024-09-10T14:51:21+00:00

The old page API is being gradually replaced and converted to use folio
to improve code readability and avoid repeated conversion between page
and folio. And memcpy_to_page() can be replaced with memcpy_to_folio().
But there is no memzero_folio(), but it can be replaced equivalently by
folio_zero_range().

Signed-off-by: Li Zetao 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: convert lzo_decompress() to take a folio

2024-09-10T14:51:21+00:00

The old page API is being gradually replaced and converted to use folio
to improve code readability and avoid repeated conversion between page
and folio. And memcpy_to_page() can be replaced with memcpy_to_folio().
But there is no memzero_folio(), but it can be replaced equivalently by
folio_zero_range().

Signed-off-by: Li Zetao 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: convert zlib_decompress() to take a folio

2024-09-10T14:51:21+00:00

The old page API is being gradually replaced and converted to use folio
to improve code readability and avoid repeated conversion between page
and folio. And memcpy_to_page() can be replaced with memcpy_to_folio().
But there is no memzero_folio(), but it can be replaced equivalently by
folio_zero_range().

Signed-off-by: Li Zetao 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: do not hold the extent lock for entire read

2024-09-10T14:51:20+00:00

Historically we've held the extent lock throughout the entire read.
There's been a few reasons for this, but it's mostly just caused us
problems.  For example, this prevents us from allowing page faults
during direct io reads, because we could deadlock.  This has forced us
to only allow 4k reads at a time for io_uring NOWAIT requests because we
have no idea if we'll be forced to page fault and thus have to do a
whole lot of work.

On the buffered side we are protected by the page lock, as long as we're
reading things like buffered writes, punch hole, and even direct IO to a
certain degree will get hung up on the page lock while the page is in
flight.

On the direct side we have the dio extent lock, which acts much like the
way the extent lock worked previously to this patch, however just for
direct reads.  This protects direct reads from concurrent direct writes,
while we're protected from buffered writes via the inode lock.

Now that we're protected in all cases, narrow the extent lock to the
part where we're getting the extent map to submit the reads, no longer
holding the extent lock for the entire read operation.  Push the extent
lock down into do_readpage() so that we're only grabbing it when looking
up the extent map.  This portion was contributed by Goldwyn.

Co-developed-by: Goldwyn Rodrigues 
Reviewed-by: Goldwyn Rodrigues 
Signed-off-by: Josef Bacik 
Signed-off-by: David Sterba

btrfs: rename btrfs_submit_bio() to btrfs_submit_bbio()

2024-09-10T14:51:19+00:00

The function name is a bit misleading as it submits the btrfs_bio
(bbio), rename it so we can use btrfs_submit_bio() when an actual bio is
submitted.

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

btrfs: convert add_ra_bio_pages() to use only folios

2024-09-10T14:51:13+00:00

Willy is going to get rid of page->index, and add_ra_bio_pages uses
page->index.  Make his life easier by converting add_ra_bio_pages to use
folios so that we are no longer using page->index.

Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

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