From: David Howells <dhowells@xxxxxxxxxx> Subject: mm/readahead: pass readahead_control to force_page_cache_ra Reimplement force_page_cache_readahead() as a wrapper around force_page_cache_ra(). Pass the existing readahead_control from page_cache_sync_readahead(). Link: https://lkml.kernel.org/r/20200903140844.14194-7-willy@xxxxxxxxxxxxx Signed-off-by: David Howells <dhowells@xxxxxxxxxx> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Eric Biggers <ebiggers@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/internal.h | 13 +++++++++---- mm/readahead.c | 18 ++++++++++-------- 2 files changed, 19 insertions(+), 12 deletions(-) --- a/mm/internal.h~mm-readahead-pass-readahead_control-to-force_page_cache_ra +++ a/mm/internal.h @@ -49,10 +49,15 @@ void unmap_page_range(struct mmu_gather unsigned long addr, unsigned long end, struct zap_details *details); -void force_page_cache_readahead(struct address_space *, struct file *, - pgoff_t index, unsigned long nr_to_read); -void do_page_cache_ra(struct readahead_control *, - unsigned long nr_to_read, unsigned long lookahead_size); +void do_page_cache_ra(struct readahead_control *, unsigned long nr_to_read, + unsigned long lookahead_size); +void force_page_cache_ra(struct readahead_control *, unsigned long nr); +static inline void force_page_cache_readahead(struct address_space *mapping, + struct file *file, pgoff_t index, unsigned long nr_to_read) +{ + DEFINE_READAHEAD(ractl, file, mapping, index); + force_page_cache_ra(&ractl, nr_to_read); +} /* * Submit IO for the read-ahead request in file_ra_state. --- a/mm/readahead.c~mm-readahead-pass-readahead_control-to-force_page_cache_ra +++ a/mm/readahead.c @@ -271,13 +271,13 @@ void do_page_cache_ra(struct readahead_c * Chunk the readahead into 2 megabyte units, so that we don't pin too much * memory at once. */ -void force_page_cache_readahead(struct address_space *mapping, - struct file *file, pgoff_t index, unsigned long nr_to_read) +void force_page_cache_ra(struct readahead_control *ractl, + unsigned long nr_to_read) { - DEFINE_READAHEAD(ractl, file, mapping, index); + struct address_space *mapping = ractl->mapping; struct backing_dev_info *bdi = inode_to_bdi(mapping->host); - struct file_ra_state *ra = &file->f_ra; - unsigned long max_pages; + struct file_ra_state *ra = &ractl->file->f_ra; + unsigned long max_pages, index; if (unlikely(!mapping->a_ops->readpage && !mapping->a_ops->readpages && !mapping->a_ops->readahead)) @@ -287,14 +287,16 @@ void force_page_cache_readahead(struct a * If the request exceeds the readahead window, allow the read to * be up to the optimal hardware IO size */ + index = readahead_index(ractl); max_pages = max_t(unsigned long, bdi->io_pages, ra->ra_pages); - nr_to_read = min(nr_to_read, max_pages); + nr_to_read = min_t(unsigned long, nr_to_read, max_pages); while (nr_to_read) { unsigned long this_chunk = (2 * 1024 * 1024) / PAGE_SIZE; if (this_chunk > nr_to_read) this_chunk = nr_to_read; - do_page_cache_ra(&ractl, this_chunk, 0); + ractl->_index = index; + do_page_cache_ra(ractl, this_chunk, 0); index += this_chunk; nr_to_read -= this_chunk; @@ -576,7 +578,7 @@ void page_cache_sync_readahead(struct ad /* be dumb */ if (filp && (filp->f_mode & FMODE_RANDOM)) { - force_page_cache_readahead(mapping, filp, index, req_count); + force_page_cache_ra(&ractl, req_count); return; } _
