From 2a754b51aacb122cec25c849e3cf7f5503cc3ec6 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 19 Oct 2007 17:16:53 +1000 Subject: [PATCH] [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 --- fs/jffs2/file.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c index 023a17539dd4..f9c5dd6f4b64 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)); -- 2.30.2