[JFFS2] Fix return value from jffs2_write_end() (2a754b51) · Commits · 戴 / test

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

+4 −7

Original line number	Diff line number	Diff line
		@@ -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));

Admin message