Commit 32c0a6bc authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by David Sterba
Browse files

btrfs: add and use readahead_batch_length 



Implement readahead_batch_length() to determine the number of bytes in
the current batch of readahead pages and use it in btrfs. Also use the
readahead_pos to get the offset.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 183ebab7

fs/btrfs/extent_io.c

+2 −4
Original line number Diff line number Diff line
@@ -4650,10 +4650,8 @@ void extent_readahead(struct readahead_control *rac) 
	int nr;



	while ((nr = readahead_page_batch(rac, pagepool))) {

		u64 contig_start = page_offset(pagepool[0]);

		u64 contig_end = page_offset(pagepool[nr - 1]) + PAGE_SIZE - 1;



		ASSERT(contig_start + nr * PAGE_SIZE - 1 == contig_end);

		u64 contig_start = readahead_pos(rac);

		u64 contig_end = contig_start + readahead_batch_length(rac) - 1;



		contiguous_readpages(pagepool, nr, contig_start, contig_end,

				&em_cached, &bio, &bio_flags, &prev_em_start);

include/linux/pagemap.h

+9 −0
Original line number Diff line number Diff line
@@ -981,6 +981,15 @@ static inline unsigned int readahead_count(struct readahead_control *rac) 
	return rac->_nr_pages;

}



/**

 * readahead_batch_length - The number of bytes in the current batch.

 * @rac: The readahead request.

 */

static inline loff_t readahead_batch_length(struct readahead_control *rac)

{

	return rac->_batch_count * PAGE_SIZE;

}



static inline unsigned long dir_pages(struct inode *inode)

{

	return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >>