[RFC PATCH 6/6] mm: Pass a file_ra_state struct into force_page_cache_readahead() [ver #2]

[David Howells <dhowells@xxxxxxxxxx>]

Pass a file_ra_state struct into force_page_cache_readahead().  One caller
has one that should be passed in and the other doesn't, but the former
needs to pass its in.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

 mm/fadvise.c   |    3 ++-
 mm/internal.h  |    3 ++-
 mm/readahead.c |    5 ++---
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/mm/fadvise.c b/mm/fadvise.c
index 997f7c16690a..e1b09975caaa 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -106,7 +106,8 @@ int generic_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
 
 		{
 			DEFINE_READAHEAD(rac, file, mapping, start_index);
-			force_page_cache_readahead(&rac, nrpages);
+			force_page_cache_readahead(&rac, &rac.file->f_ra,
+						   nrpages);
 		}
 		break;
 	case POSIX_FADV_NOREUSE:
diff --git a/mm/internal.h b/mm/internal.h
index d62df5559500..ff7b549f6a9d 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -49,7 +49,8 @@ void unmap_page_range(struct mmu_gather *tlb,
 			     unsigned long addr, unsigned long end,
 			     struct zap_details *details);
 
-void force_page_cache_readahead(struct readahead_control *, unsigned long);
+void force_page_cache_readahead(struct readahead_control *, struct file_ra_state *,
+				unsigned long);
 void __do_page_cache_readahead(struct readahead_control *,
 		unsigned long nr_to_read, unsigned long lookahead_size);
 
diff --git a/mm/readahead.c b/mm/readahead.c
index d8e3e59e4c46..3f3ce65afc64 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -272,11 +272,10 @@ void __do_page_cache_readahead(struct readahead_control *rac,
  * memory at once.
  */
 void force_page_cache_readahead(struct readahead_control *rac,
-		unsigned long nr_to_read)
+		struct file_ra_state *ra, unsigned long nr_to_read)
 {
 	struct address_space *mapping = rac->mapping;
 	struct backing_dev_info *bdi = inode_to_bdi(mapping->host);
-	struct file_ra_state *ra = &rac->file->f_ra;
 	unsigned long max_pages, index;
 
 	if (unlikely(!mapping->a_ops->readpage && !mapping->a_ops->readpages &&
@@ -655,7 +654,7 @@ void page_cache_sync_readahead(struct readahead_control *rac,
 
 	/* be dumb */
 	if (rac->file && (rac->file->f_mode & FMODE_RANDOM)) {
-		force_page_cache_readahead(rac, req_count);
+		force_page_cache_readahead(rac, ra, req_count);
 		return;
 	}