From 602c89d2e3e8652f94a697c9a919be739b9bcdd5 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Thu, 25 Mar 2010 14:32:43 +0000 Subject: GFS2: Clean up stuffed file copying If the inode size was corrupt for stuffed files, it was possible for the copying of data to overrun the block and/or page. This patch checks for that condition so that this is no longer possible. This is also preparation for the new truncate sequence patch which requires the ability to have stuffed files with larger sizes than (disk block size - sizeof(on disk inode)) with the restriction that only the initial part of the file may be non-zero. Signed-off-by: Steven Whitehouse --- fs/gfs2/aops.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs/gfs2/aops.c') diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 0c1d0b82dcf..a739a0a4806 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -418,6 +418,7 @@ static int gfs2_jdata_writepages(struct address_space *mapping, static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) { struct buffer_head *dibh; + u64 dsize = i_size_read(&ip->i_inode); void *kaddr; int error; @@ -437,9 +438,10 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) return error; kaddr = kmap_atomic(page, KM_USER0); - memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), - ip->i_disksize); - memset(kaddr + ip->i_disksize, 0, PAGE_CACHE_SIZE - ip->i_disksize); + if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode))) + dsize = (dibh->b_size - sizeof(struct gfs2_dinode)); + memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); + memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize); kunmap_atomic(kaddr, KM_USER0); flush_dcache_page(page); brelse(dibh); -- cgit v1.2.3