Commit b4cf4792 authored by Zhang Yi's avatar Zhang Yi Committed by Zhihao Cheng
Browse files

iomap: reduce unnecessary state_lock when setting ifs uptodate and dirty bits 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9DN5Z


CVE: NA

--------------------------------

When doing buffered write, we set uptodate and drity bits of the written
range separately, it holds the ifs->state_lock twice when blocksize <
folio size, which is redundant. After large folio is supported, the
spinlock could affect more about the performance, merge them could
reduce some unnecessary locking overhead and gets some performance gain.

Suggested-by: default avatarDave Chinner <david@fromorbit.com>
Signed-off-by: default avatarZhang Yi <yi.zhang@huawei.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Conflicts:
	fs/iomap/buffered-io.c
[ 15d09f86("iomap: export __iomap_write_{begin|end}") is applied. ]
Signed-off-by: default avatarZhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: default avatarZhihao Cheng <chengzhihao@huaweicloud.com>
parent b8517919

fs/iomap/buffered-io.c

+35 −3
Original line number Diff line number Diff line
@@ -211,6 +211,37 @@ bool iomap_is_fully_dirty(struct folio *folio, size_t from, size_t count) 
}

EXPORT_SYMBOL_GPL(iomap_is_fully_dirty);



static void ifs_set_range_dirty_uptodate(struct folio *folio,

		struct iomap_folio_state *ifs, size_t off, size_t len)

{

	struct inode *inode = folio->mapping->host;

	unsigned int blks_per_folio = i_blocks_per_folio(inode, folio);

	unsigned int first_blk = (off >> inode->i_blkbits);

	unsigned int last_blk = (off + len - 1) >> inode->i_blkbits;

	unsigned int nr_blks = last_blk - first_blk + 1;

	unsigned long flags;



	spin_lock_irqsave(&ifs->state_lock, flags);

	bitmap_set(ifs->state, first_blk, nr_blks);

	if (ifs_is_fully_uptodate(folio, ifs))

		folio_mark_uptodate(folio);

	bitmap_set(ifs->state, first_blk + blks_per_folio, nr_blks);

	spin_unlock_irqrestore(&ifs->state_lock, flags);

}



static void iomap_set_range_dirty_uptodate(struct folio *folio,

		size_t off, size_t len)

{

	struct iomap_folio_state *ifs = folio->private;



	if (ifs)

		ifs_set_range_dirty_uptodate(folio, ifs, off, len);

	else

		folio_mark_uptodate(folio);



	filemap_dirty_folio(folio->mapping, folio);

}



static struct iomap_folio_state *ifs_alloc(struct inode *inode,

		struct folio *folio, unsigned int flags)

{
@@ -867,6 +898,8 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, 
bool __iomap_write_end(struct inode *inode, loff_t pos, size_t len,

		size_t copied, struct folio *folio)

{

	size_t from = offset_in_folio(folio, pos);



	flush_dcache_folio(folio);



	/*
@@ -882,9 +915,8 @@ bool __iomap_write_end(struct inode *inode, loff_t pos, size_t len, 
	 */

	if (unlikely(copied < len && !folio_test_uptodate(folio)))

		return false;

	iomap_set_range_uptodate(folio, offset_in_folio(folio, pos), len);

	iomap_set_range_dirty(folio, offset_in_folio(folio, pos), copied);

	filemap_dirty_folio(inode->i_mapping, folio);



	iomap_set_range_dirty_uptodate(folio, from, copied);

	return true;

}

EXPORT_SYMBOL_GPL(__iomap_write_end);