From: Nick Piggin Date: Fri, 19 Oct 2007 07:16:53 +0000 (+1000) Subject: [JFFS2] Fix return value from jffs2_write_end() X-Git-Tag: v2.6.24-rc1~32^2~1 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a754b51aacb122cec25c849e3cf7f5503cc3ec6;p=linux-2.6 [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 Signed-off-by: David Woodhouse --- diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c index 023a17539d..f9c5dd6f4b 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));