From 32c0a6bcaa1f57e80f67bf3ae2b35d00cea8361a Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Sun, 21 Mar 2021 21:03:11 +0000 Subject: [PATCH 1/1] 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) Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 6 ++---- include/linux/pagemap.h | 9 +++++++++ 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 18e69e1a5f9c..a50adbd8808d 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -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); diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 8c9947fd62f3..4c1ffe1d5dac 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -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) >> -- 2.25.1