From: Al Viro Date: Tue, 6 Sep 2016 02:06:35 +0000 (-0400) Subject: fix gfs2_stuffed_write_end() on short copies X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=43388b21e72d36204822bcc3119e42abe6ebceef;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git fix gfs2_stuffed_write_end() on short copies a) the page is uptodate - ->write_begin() would either fail (in which case we don't reach ->write_end()), or unstuff the inode, or find the page already uptodate, or do a successful call of stuffed_readpage(), which would've made it uptodate b) zeroing the tail in pagecache is wrong. kill -9 at the right time while writing unmodified file contents to the same file should _not_ leave us in a situation when read() from the file will be reporting it full of zeroes. Especially since that effect will be transient - at some later point the page will be evicted and then we'll be back to the real file contents. Signed-off-by: Al Viro --- diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 5a6f52ea2722..6b039d7ce160 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -839,12 +839,10 @@ static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode))); kaddr = kmap_atomic(page); memcpy(buf + pos, kaddr + pos, copied); - memset(kaddr + pos + copied, 0, len - copied); flush_dcache_page(page); kunmap_atomic(kaddr); - if (!PageUptodate(page)) - SetPageUptodate(page); + WARN_ON(!PageUptodate(page)); unlock_page(page); put_page(page);