From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox (Oracle) Date: Sun, 4 Oct 2020 19:04:21 +0100 Subject: [Ocfs2-devel] [PATCH 0/7] Fix a pile of 4GB file problems on 32-bit Message-ID: <20201004180428.14494-1-willy@infradead.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , ericvh@gmail.com, lucho@ionkov.net, viro@zeniv.linux.org.uk, jlayton@kernel.org, idryomov@gmail.com, mark@fasheh.com, jlbec@evilplan.org, joseph.qi@linux.alibaba.com, v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, ocfs2-devel@oss.oracle.com, linux-btrfs@vger.kernel.org, clm@fb.com, josef@toxicpanda.com, dsterba@suse.com I caught a bug in my own code where I forgot to cast to loff_t before shifting. So I thought I'd grep around and see if I could find any other occurrences. I found a few that were clearly bugs, and they're fixed below. There are other places where we don't cast, and I think they're OK. For example, some places we have a 'nr_pages' being shifted by PAGE_SHIFT, and that's probably OK because it's probably a single I/O. Also, I didn't touch AFFS or ROMFS or some other filesystems which probably have never seen a 4GB file in their lives. Might be worth fixing to be sure nobody copies bad code from them, but not worth cc'ing stable for. I didn't look for SECTOR_SHIFT or SECTOR_SIZE (or bare 9/512), just PAGE_SIZE and PAGE_SHIFT. I can't find a GCC warning to enable for this pattern, so I filed https://urldefense.com/v3/__https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97287__;!!GqivPVa7Brio!JmJRfLO1W1WY_UNpWJIfK5J2F0viNTrZ3l7xIrCKzl03yThvlPmVBeZHbHY6hZu2IJ2u7Q$ Matthew Wilcox (Oracle) (7): 9P: Cast to loff_t before multiplying buffer: Promote to unsigned long long before shifting ceph: Promote to unsigned long long before shifting ocfs2: Promote to unsigned long long before shifting btrfs: Promote to unsigned long long before shifting btrfs: Promote to unsigned long long before shifting btrfs: Promote to unsigned long long before multiplying fs/9p/vfs_file.c | 4 ++-- fs/btrfs/ioctl.c | 6 +++--- fs/btrfs/raid56.c | 2 +- fs/btrfs/scrub.c | 25 ++++++++++++++++--------- fs/buffer.c | 2 +- fs/ceph/addr.c | 2 +- fs/ocfs2/alloc.c | 2 +- 7 files changed, 25 insertions(+), 18 deletions(-) -- 2.28.0