mtd/fs/jffs2 file.c,1.58.2.7,1.58.2.8

[David Woodhouse]

Update of /home/cvs/mtd/fs/jffs2
In directory phoenix.infradead.org:/tmp/cvs-serv31478

Modified Files:
      Tag: jffs2-2_4-branch
	file.c 
Log Message:
Potential fix for truncate/readpage race.

Index: file.c
===================================================================
RCS file: /home/cvs/mtd/fs/jffs2/file.c,v
retrieving revision 1.58.2.7
retrieving revision 1.58.2.8
diff -u -r1.58.2.7 -r1.58.2.8
--- file.c	2 Nov 2003 13:51:17 -0000	1.58.2.7
+++ file.c	26 Jan 2004 12:40:32 -0000	1.58.2.8
@@ -1,7 +1,7 @@
 /*
  * JFFS2 -- Journalling Flash File System, Version 2.
  *
- * Copyright (C) 2001 Red Hat, Inc.
+ * Copyright (C) 2001-2004 Red Hat, Inc.
  *
  * Created by David Woodhouse <dwmw2 at cambridge.redhat.com>
  *
@@ -197,10 +197,8 @@
 
 	old_metadata = f->metadata;
 
-	if (inode->i_size > ri->isize) {
-		vmtruncate(inode, ri->isize);
+	if (inode->i_size > ri->isize)
 		jffs2_truncate_fraglist (c, &f->fraglist, ri->isize);
-	}
 
 	if (inode->i_size < ri->isize) {
 		jffs2_add_full_dnode_to_inode(c, f, new_metadata);
@@ -215,6 +213,15 @@
 	}
 	jffs2_free_raw_inode(ri);
 	up(&f->sem);
+
+	/* We have to do the vmtruncate() without f->sem held, since
+	   some pages may be locked and waiting for it in readpage().
+	   We are protected from a simultaneous write() extending i_size
+	   back past iattr->ia_size, because do_truncate() holds the
+	   generic inode semaphore. */
+	if (inode->i_size > ri->isize)
+		vmtruncate(inode, ri->isize);
+
 	return 0;
 }