nilfs2: fix missed-sync issue for do_sync_mapping_range()

Chris Mason pointed out that there is a missed sync issue in
nilfs_writepages():

On Wed, 17 Dec 2008 21:52:55 -0500, Chris Mason wrote:
> It looks like nilfs_writepage ignores WB_SYNC_NONE, which is used by
> do_sync_mapping_range().

where WB_SYNC_NONE in do_sync_mapping_range() was replaced with
WB_SYNC_ALL by Nick's patch (commit:
ee53a891f47444c53318b98dac947ede963db400).

This fixes the problem by letting nilfs_writepages() write out the log of
file data within the range if sync_mode is WB_SYNC_ALL.

This involves removal of nilfs_file_aio_write() which was previously
needed to ensure O_SYNC sync writes.

Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 7 deletions

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index b4697d9d7e5d..289d1798decb 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -24,6 +24,7 @@
 #include <linux/buffer_head.h>
 #include <linux/mpage.h>
 #include <linux/writeback.h>
+#include <linux/uio.h>
 #include "nilfs.h"
 #include "segment.h"
 #include "page.h"
@@ -145,8 +146,14 @@ static int nilfs_readpages(struct file *file, struct address_space *mapping,
 static int nilfs_writepages(struct address_space *mapping,
                             struct writeback_control *wbc)
 {
-        /* This empty method is required not to call generic_writepages() */
-        return 0;
+        struct inode *inode = mapping->host;
+        int err = 0;
+
+        if (wbc->sync_mode == WB_SYNC_ALL)
+                err = nilfs_construct_dsync_segment(inode->i_sb, inode,
+                                                    wbc->range_start,
+                                                    wbc->range_end);
+        return err;
 }
 
 static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
@@ -225,11 +232,6 @@ nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
         ssize_t size;
-        int err;
-
-        err = nilfs_construct_dsync_segment(inode->i_sb, inode);
-        if (unlikely(err))
-                return err;
 
         if (rw == WRITE)
                 return 0;