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: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Matthew Wilcox (Oracle) 2021-03-21 21:03:11 +00:00 committed by David Sterba
parent 183ebab766
commit 32c0a6bcaa
2 changed files with 11 additions and 4 deletions

View file

@ -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);

View file

@ -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) >>