fat: Opencode sync_page_range_nolock()

fat_cont_expand() is the only user of sync_page_range_nolock(). It's also the
only user of generic_osync_inode() which does not have a file open.  So
opencode needed actions for FAT so that we can convert generic_osync_inode() to
a standard syncing path.

Update a comment about generic_osync_inode().

CC: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jan Kara <jack@suse.cz>

2 files changed, 22 insertions, 4 deletions

diff --git a/fs/fat/file.c b/fs/fat/file.c
index f042b965c95c..e8c159de236b 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -176,8 +176,26 @@ static int fat_cont_expand(struct inode *inode, loff_t size)
 
         inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
         mark_inode_dirty(inode);
-        if (IS_SYNC(inode))
-                err = sync_page_range_nolock(inode, mapping, start, count);
+        if (IS_SYNC(inode)) {
+                int err2;
+
+                /*
+                 * Opencode syncing since we don't have a file open to use
+                 * standard fsync path.
+                 */
+                err = filemap_fdatawrite_range(mapping, start,
+                                               start + count - 1);
+                err2 = sync_mapping_buffers(mapping);
+                if (!err)
+                        err = err2;
+                err2 = write_inode_now(inode, 1);
+                if (!err)
+                        err = err2;
+                if (!err) {
+                        err =  filemap_fdatawait_range(mapping, start,
+                                                       start + count - 1);
+                }
+        }
 out:
         return err;
 }
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index a6c20473dfd7..4e35be873e09 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -119,8 +119,8 @@ int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
                 MSDOS_I(inode)->i_start = new_dclus;
                 MSDOS_I(inode)->i_logstart = new_dclus;
                 /*
-                 * Since generic_osync_inode() synchronize later if
-                 * this is not directory, we don't here.
+                 * Since generic_write_sync() synchronizes regular files later,
+                 * we sync here only directories.
                  */
                 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
                         ret = fat_sync_inode(inode);