[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, 6 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e7bd0d92600..3e4ba9cb7f8 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -644,10 +644,7 @@ int nfs_sync_mapping(struct address_space *mapping)
         if (mapping->nrpages == 0)
                 return 0;
         unmap_mapping_range(mapping, 0, 0, 0);
-        ret = filemap_fdatawrite(mapping);
-        if (ret != 0)
-                goto out;
-        ret = filemap_fdatawait(mapping);
+        ret = filemap_write_and_wait(mapping);
         if (ret != 0)
                 goto out;
         ret = nfs_wb_all(mapping->host);
@@ -864,8 +861,7 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
         nfs_begin_data_update(inode);
         /* Write all dirty data if we're changing file permissions or size */
         if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE)) != 0) {
-                if (filemap_fdatawrite(inode->i_mapping) == 0)
-                        filemap_fdatawait(inode->i_mapping);
+                filemap_write_and_wait(inode->i_mapping);
                 nfs_wb_all(inode);
         }
         /*