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(). Signed-off-by: David Howells <[email protected]> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Eric Biggers <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
akvadrako · Oct 16, 2020 · 7b3df3b · 7b3df3b
1 parent 6e4af69
commit 7b3df3b
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Showing 2 changed files with 19 additions and 12 deletions.
diff --git a/mm/internal.h b/mm/internal.h
@@ -49,10 +49,15 @@ void unmap_page_range(struct mmu_gather *tlb,
 			     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.

diff --git a/mm/readahead.c b/mm/readahead.c
@@ -271,13 +271,13 @@ void do_page_cache_ra(struct readahead_control *ractl,
  * 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 address_space *mapping,
 	 * 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 address_space *mapping,
 
 	/* 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;
 	}