[PATCH] Fix and add EXPORT_SYMBOL(filemap_write_and_wait)

This patch add EXPORT_SYMBOL(filemap_write_and_wait) and use it.

See mm/filemap.c:

And changes the filemap_write_and_wait() and filemap_write_and_wait_range().

Current filemap_write_and_wait() doesn't wait if filemap_fdatawrite()
returns error.  However, even if filemap_fdatawrite() returned an
error, it may have submitted the partially data pages to the device.
(e.g. in the case of -ENOSPC)

<quotation>
Andrew Morton writes,

If filemap_fdatawrite() returns an error, this might be due to some
I/O problem: dead disk, unplugged cable, etc.  Given the generally
crappy quality of the kernel's handling of such exceptions, there's a
good chance that the filemap_fdatawait() will get stuck in D state
forever.
</quotation>

So, this patch doesn't wait if filemap_fdatawrite() returns the -EIO.

Trond, could you please review the nfs part?  Especially I'm not sure,
nfs must use the "filemap_fdatawrite(inode->i_mapping) == 0", or not.

Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/fs/jfs/jfs_umount.c b/fs/jfs/jfs_umount.c
index 5cf91785b541..21eaf7ac0fcb 100644
--- a/fs/jfs/jfs_umount.c
+++ b/fs/jfs/jfs_umount.c
@@ -108,8 +108,7 @@ int jfs_umount(struct super_block *sb)
          * Make sure all metadata makes it to disk before we mark
          * the superblock as clean
          */
-        filemap_fdatawrite(sbi->direct_inode->i_mapping);
-        filemap_fdatawait(sbi->direct_inode->i_mapping);
+        filemap_write_and_wait(sbi->direct_inode->i_mapping);
 
         /*
          * ensure all file system file pages are propagated to their
@@ -161,8 +160,7 @@ int jfs_umount_rw(struct super_block *sb)
          * mark the superblock clean before everything is flushed to
          * disk.
          */
-        filemap_fdatawrite(sbi->direct_inode->i_mapping);
-        filemap_fdatawait(sbi->direct_inode->i_mapping);
+        filemap_write_and_wait(sbi->direct_inode->i_mapping);
 
         updateSuper(sb, FM_CLEAN);