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btrfs: only clear EXTENT_LOCK bit in extent_invalidatepage

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extent_invalidatepage() will try to clear all possible bits since it's
calling clear_extent_bit() with delete == 1.

This is currently fine, since for btree io tree, it only utilizes
EXTENT_LOCK bit.  But this could be a problem for later subpage support,
which will utilize extra io tree bit to represent additional info.

This patch will just convert that clear_extent_bit() to
unlock_extent_cached().

For current code since only EXTENT_LOCKED bit is utilized, this doesn't
change the behavior, but provides a much cleaner basis for incoming
subpage support.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2020-11-13 20:51:39 +08:00 committed by David Sterba
parent 8e1dc982ed
commit 829ddec922
1 changed files with 10 additions and 2 deletions
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12
fs/btrfs/extent_io.c
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@ -4431,14 +4431,22 @@ int extent_invalidatepage(struct extent_io_tree *tree,
u64 end = start + PAGE_SIZE - 1;
size_t blocksize = page->mapping->host->i_sb->s_blocksize;
/* This function is only called for the btree inode */
ASSERT(tree->owner == IO_TREE_BTREE_INODE_IO);
start += ALIGN(offset, blocksize);
if (start > end)
return 0;
lock_extent_bits(tree, start, end, &cached_state);
wait_on_page_writeback(page);
clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING, 1, 1, &cached_state);
/*
* Currently for btree io tree, only EXTENT_LOCKED is utilized,
* so here we only need to unlock the extent range to free any
* existing extent state.
*/
unlock_extent_cached(tree, start, end, &cached_state);
return 0;
}