[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, 8 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 55023231e46..263df0f192a 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -153,14 +153,8 @@ int sync_blockdev(struct block_device *bdev)
 {
 	int ret = 0;
 
-	if (bdev) {
-		int err;
-
-		ret = filemap_fdatawrite(bdev->bd_inode->i_mapping);
-		err = filemap_fdatawait(bdev->bd_inode->i_mapping);
-		if (!ret)
-			ret = err;
-	}
+	if (bdev)
+		ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
 	return ret;
 }
 EXPORT_SYMBOL(sync_blockdev);