[PATCH 6/9] btrfs: remove redundant i_size check in __extent_writepage_io()

Omar Sandoval
2019-12-03T01:34:42Z

From: Omar Sandoval <osandov@fb.com>

In __extent_writepage_io(), we check whether
i_size <= page_offset(page).

Note that if i_size < page_offset(page), then
i_size >> PAGE_SHIFT < page->index. If i_size == page_offset(page), then
i_size >> PAGE_SHIFT == page->index && offset_in_page(i_size) == 0.

__extent_writepage() already has a check for these cases that
returns without calling __extent_writepage_io():

end_index = i_size >> PAGE_SHIFT
pg_offset = offset_in_page(i_size);
if (page->index > end_index ||
(page->index == end_index && !pg_offset)) {
page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
unlock_page(page);
return 0;
}

Get rid of the one in __extent_writepage_io(), which was obsoleted in
211c17f51f46 ("Fix corners in writepage and btrfs_truncate_page").

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
fs/btrfs/extent_io.c | 6 ------
1 file changed, 6 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8622282db31e..635f5d2954a4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3455,11 +3455,6 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
update_nr_written(wbc, nr_written + 1);

end = page_end;
- if (i_size <= start) {
- btrfs_writepage_endio_finish_ordered(page, start, page_end, 1);
- goto done;
- }
-
blocksize = inode->i_sb->s_blocksize;

while (cur <= end) {
@@ -3540,7 +3535,6 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
pg_offset += iosize;
nr++;
}
-done:
*nr_ret = nr;
return ret;
}
--
2.24.0