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btrfs: do not use GFP_ATOMIC in the read endio

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We have done read endio in an async thread for a very, very long time,
which makes the use of GFP_ATOMIC and unlock_extent_atomic() unneeded in
our read endio path.  We've noticed under heavy memory pressure in our
fleet that we can fail these allocations, and then often trip a
BUG_ON(!allocation), which isn't an ideal outcome.  Begin to address
this by simply not using GFP_ATOMIC, which will allow us to do things
like actually allocate a extent state when doing
set_extent_bits(UPTODATE) in the endio handler.

End io handlers are not called in atomic context, besides we have been
allocating failrec with GFP_NOFS so we'd notice there's a problem.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Josef Bacik 2022-10-14 10:00:39 -04:00 committed by David Sterba
parent 7248e0cebb
commit 48acc47d78
1 changed files with 4 additions and 4 deletions
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8
fs/btrfs/extent_io.c
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@ -897,9 +897,9 @@ static void end_sector_io(struct page *page, u64 offset, bool uptodate)
end_page_read(page, uptodate, offset, sectorsize);
if (uptodate)
set_extent_uptodate(&inode->io_tree, offset,
offset + sectorsize - 1, &cached, GFP_ATOMIC);
unlock_extent_atomic(&inode->io_tree, offset, offset + sectorsize - 1,
&cached);
offset + sectorsize - 1, &cached, GFP_NOFS);
unlock_extent(&inode->io_tree, offset, offset + sectorsize - 1,
&cached);
}
static void submit_data_read_repair(struct inode *inode,
@ -1103,7 +1103,7 @@ static void endio_readpage_release_extent(struct processed_extent *processed,
* Now we don't have range contiguous to the processed range, release
* the processed range now.
*/
unlock_extent_atomic(tree, processed->start, processed->end, &cached);
unlock_extent(tree, processed->start, processed->end, &cached);
update:
/* Update processed to current range */