From 2a754b51aacb122cec25c849e3cf7f5503cc3ec6 Mon Sep 17 00:00:00 2001
From: Nick Piggin <nickpiggin@yahoo.com.au>
Date: Fri, 19 Oct 2007 17:16:53 +1000
Subject: [JFFS2] Fix return value from jffs2_write_end()
jffs2_write_end() is sometimes passing back a "written" length greater
than the length we passed into it, leading to a BUG at mm/filemap.c:1749
when used with unionfs.
It happens because we actually write more than was requested, to reduce
log fragmentation. These "longer" writes are fine, but they shouldn't
get propagated back to the vm/vfs.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
---
fs/jffs2/file.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
(limited to 'fs')
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index 023a17539dd..f9c5dd6f4b6 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -255,7 +255,7 @@ static int jffs2_write_end(struct file *filp, struct address_space *mapping,
_whole_ page. This helps to reduce the number of
nodes in files which have many short writes, like
syslog files. */
- start = aligned_start = 0;
+ aligned_start = 0;
}
ri = jffs2_alloc_raw_inode();
@@ -291,14 +291,11 @@ static int jffs2_write_end(struct file *filp, struct address_space *mapping,
}
/* Adjust writtenlen for the padding we did, so we don't confuse our caller */
- if (writtenlen < (start&3))
- writtenlen = 0;
- else
- writtenlen -= (start&3);
+ writtenlen -= min(writtenlen, (start - aligned_start));
if (writtenlen) {
- if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
- inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
+ if (inode->i_size < pos + writtenlen) {
+ inode->i_size = pos + writtenlen;
inode->i_blocks = (inode->i_size + 511) >> 9;
inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
--
cgit