Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

[linux-2.6-microblaze.git] / mm / readahead.c

diff --git a/mm/readahead.c b/mm/readahead.c
index c6ffb76..c5b0457 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -552,15 +552,23 @@ readit:
 void page_cache_sync_ra(struct readahead_control *ractl,
                struct file_ra_state *ra, unsigned long req_count)
 {
-       /* no read-ahead */
-       if (!ra->ra_pages)
-               return;
+       bool do_forced_ra = ractl->file && (ractl->file->f_mode & FMODE_RANDOM);
 
-       if (blk_cgroup_congested())
-               return;
+       /*
+        * Even if read-ahead is disabled, issue this request as read-ahead
+        * as we'll need it to satisfy the requested range. The forced
+        * read-ahead will do the right thing and limit the read to just the
+        * requested range, which we'll set to 1 page for this case.
+        */
+       if (!ra->ra_pages || blk_cgroup_congested()) {
+               if (!ractl->file)
+                       return;
+               req_count = 1;
+               do_forced_ra = true;
+       }
 
        /* be dumb */
-       if (ractl->file && (ractl->file->f_mode & FMODE_RANDOM)) {
+       if (do_forced_ra) {
                force_page_cache_ra(ractl, ra, req_count);
                return;
        }