[PATCH] reiserfs: reiserfs hang and performance fix for data=journal mode

In data=journal mode, reiserfs writepage needs to make sure not to trigger
transactions while being run under PF_MEMALLOC.  This patch makes sure to
redirty the page instead of forcing a transaction start in this case.

Also, calling filemap_fdata* in order to trigger io on the block device can
cause lock inversions on the page lock.  Instead, do simple batching from
flush_commit_list.

Signed-off-by: Chris Mason <mason@suse.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 60e2f2344703..b33d67bba2fd 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2363,6 +2363,13 @@ static int reiserfs_write_full_page(struct page *page,
         int bh_per_page = PAGE_CACHE_SIZE / s->s_blocksize;
         th.t_trans_id = 0;
 
+        /* no logging allowed when nonblocking or from PF_MEMALLOC */
+        if (checked && (current->flags & PF_MEMALLOC)) {
+                redirty_page_for_writepage(wbc, page);
+                unlock_page(page);
+                return 0;
+        }
+
         /* The page dirty bit is cleared before writepage is called, which
          * means we have to tell create_empty_buffers to make dirty buffers
          * The page really should be up to date at this point, so tossing