[PATCH] block new writers on frozen filesystems

[Christoph Hellwig <hch@lst.de>]

When the lockfs patches went in an important bit got lost, the call in
generic_file_write to put newly incoming writers to sleep when a
filesystem is frozen.  Nathan added back the call in the now separate
XFS write patch, and the patch for the generic code is below:


Index: mm/filemap.c
===================================================================
RCS file: /cvs/linux-2.6-xfs/mm/filemap.c,v
retrieving revision 1.14
diff -u -p -r1.14 filemap.c
--- mm/filemap.c	5 Jan 2005 14:17:31 -0000	1.14
+++ mm/filemap.c	4 Feb 2005 21:35:53 -0000
@@ -2046,6 +2046,8 @@ __generic_file_aio_write_nolock(struct k
 	count = ocount;
 	pos = *ppos;
 
+	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+
 	/* We can write back this queue in page reclaim */
 	current->backing_dev_info = mapping->backing_dev_info;
 	written = 0;