linux/fs, branch v4.8

ocfs2: fix deadlock on mmapped page in ocfs2_write_begin_nolock()

2016-09-30T22:26:52Z

The testcase "mmaptruncate" of ocfs2-test deadlocks occasionally. In this testcase, we create a 2*CLUSTER_SIZE file and mmap() on it; there are 2 process repeatedly performing the following operations respectively: one is doing memset(mmaped_addr + 2*CLUSTER_SIZE - 1, 'a', 1), while the another is playing ftruncate(fd, 2*CLUSTER_SIZE) and then ftruncate(fd, CLUSTER_SIZE) again and again. This is the backtrace when the deadlock happens: __wait_on_bit_lock+0x50/0xa0 __lock_page+0xb7/0xc0 ocfs2_write_begin_nolock+0x163f/0x1790 [ocfs2] ocfs2_page_mkwrite+0x1c7/0x2a0 [ocfs2] do_page_mkwrite+0x66/0xc0 handle_mm_fault+0x685/0x1350 __do_page_fault+0x1d8/0x4d0 trace_do_page_fault+0x37/0xf0 do_async_page_fault+0x19/0x70 async_page_fault+0x28/0x30 In ocfs2_write_begin_nolock(), we first grab the pages and then allocate disk space for this write; ocfs2_try_to_free_truncate_log() will be called if -ENOSPC is returned; if we're lucky to get enough clusters, which is usually the case, we start over again. But in ocfs2_free_write_ctxt() the target page isn't unlocked, so we will deadlock when trying to grab the target page again. Also, -ENOMEM might be returned in ocfs2_grab_pages_for_write(). Another deadlock will happen in __do_page_mkwrite() if ocfs2_page_mkwrite() returns non-VM_FAULT_LOCKED, and along with a locked target page. These two errors fail on the same path, so fix them by unlocking the target page manually before ocfs2_free_write_ctxt(). Jan Kara helps me clear out the JBD2 part, and suggest the hint for root cause. Changes since v1: 1. Also put ENOMEM error case into consideration. Link: http://lkml.kernel.org/r/1474173902-32075-1-git-send-email-zren@suse.com Signed-off-by: Eric Ren Reviewed-by: He Gang Acked-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

2016-09-23T20:39:37Z

Pull btrfs fixes from Chris Mason: "Josef fixed a problem when quotas are enabled with his latest ENOSPC rework, and Jeff added more checks into the subvol ioctls to avoid tripping up lookup_one_len" * 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: ensure that file descriptor used with subvol ioctls is a dir Btrfs: handle quota reserve failure properly

Merge tag 'configfs-for-4.8-2' of git://git.infradead.org/users/hch/configfs

2016-09-23T16:45:15Z

Pull configfs fix from Christoph Hellwig: "One more trivial fix for the binary attribute code from Phil Turnbull" * tag 'configfs-for-4.8-2' of git://git.infradead.org/users/hch/configfs: configfs: Return -EFBIG from configfs_write_bin_file.

btrfs: ensure that file descriptor used with subvol ioctls is a dir

2016-09-22T00:22:16Z

If the subvol/snapshot create/destroy ioctls are passed a regular file with execute permissions set, we'll eventually Oops while trying to do inode->i_op->lookup via lookup_one_len. This patch ensures that the file descriptor refers to a directory. Fixes: cb8e70901d (Btrfs: Fix subvolume creation locking rules) Fixes: 76dda93c6a (Btrfs: add snapshot/subvolume destroy ioctl) Cc: #v2.6.29+ Signed-off-by: Jeff Mahoney Signed-off-by: Chris Mason

Btrfs: handle quota reserve failure properly

2016-09-22T00:22:16Z

btrfs/022 was spitting a warning for the case that we exceed the quota. If we fail to make our quota reservation we need to clean up our data space reservation. Thanks, Signed-off-by: Josef Bacik Tested-by: Jeff Mahoney Signed-off-by: Chris Mason

fs/proc/kcore.c: Add bounce buffer for ktext data

2016-09-20T20:32:49Z

We hit hardened usercopy feature check for kernel text access by reading kcore file: usercopy: kernel memory exposure attempt detected from ffffffff8179a01f () (4065 bytes) kernel BUG at mm/usercopy.c:75! Bypassing this check for kcore by adding bounce buffer for ktext data. Reported-by: Steve Best Fixes: f5509cc18daa ("mm: Hardened usercopy") Suggested-by: Kees Cook Signed-off-by: Jiri Olsa Acked-by: Kees Cook Signed-off-by: Linus Torvalds

fs/proc/kcore.c: Make bounce buffer global for read

2016-09-20T20:32:49Z

Next patch adds bounce buffer for ktext area, so it's convenient to have single bounce buffer for both vmalloc/module and ktext cases. Suggested-by: Linus Torvalds Signed-off-by: Jiri Olsa Acked-by: Kees Cook Signed-off-by: Linus Torvalds

Revert "ocfs2: bump up o2cb network protocol version"

2016-09-19T22:36:17Z

This reverts commit 38b52efd218b ("ocfs2: bump up o2cb network protocol version"). This commit made rolling upgrade fail. When one node is upgraded to new version with this commit, the remaining nodes will fail to establish connections to it, then the application like VMs on the remaining nodes can't be live migrated to the upgraded one. This will cause an outage. Since negotiate hb timeout behavior didn't change without this commit, so revert it. Fixes: 38b52efd218bf ("ocfs2: bump up o2cb network protocol version") Link: http://lkml.kernel.org/r/1471396924-10375-1-git-send-email-junxiao.bi@oracle.com Signed-off-by: Junxiao Bi Cc: Mark Fasheh Cc: Joel Becker Cc: Joseph Qi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ocfs2: fix start offset to ocfs2_zero_range_for_truncate()

2016-09-19T22:36:17Z

If we punch a hole on a reflink such that following conditions are met: 1. start offset is on a cluster boundary 2. end offset is not on a cluster boundary 3. (end offset is somewhere in another extent) or (hole range > MAX_CONTIG_BYTES(1MB)), we dont COW the first cluster starting at the start offset. But in this case, we were wrongly passing this cluster to ocfs2_zero_range_for_truncate() to zero out. This will modify the cluster in place and zero it in the source too. Fix this by skipping this cluster in such a scenario. To reproduce: 1. Create a random file of say 10 MB xfs_io -c 'pwrite -b 4k 0 10M' -f 10MBfile 2. Reflink it reflink -f 10MBfile reflnktest 3. Punch a hole at starting at cluster boundary with range greater that 1MB. You can also use a range that will put the end offset in another extent. fallocate -p -o 0 -l 1048615 reflnktest 4. sync 5. Check the first cluster in the source file. (It will be zeroed out). dd if=10MBfile iflag=direct bs= count=1 | hexdump -C Link: http://lkml.kernel.org/r/1470957147-14185-1-git-send-email-ashish.samant@oracle.com Signed-off-by: Ashish Samant Reported-by: Saar Maoz Reviewed-by: Srinivas Eeda Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Joseph Qi Cc: Eric Ren Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ocfs2: fix double unlock in case retry after free truncate log

2016-09-19T22:36:17Z

If ocfs2_reserve_cluster_bitmap_bits() fails with ENOSPC, it will try to free truncate log and then retry. Since ocfs2_try_to_free_truncate_log will lock/unlock global bitmap inode, we have to unlock it before calling this function. But when retry reserve and it fails with no global bitmap inode lock taken, it will unlock again in error handling branch and BUG. This issue also exists if no need retry and then ocfs2_inode_lock fails. So fix it. Fixes: 2070ad1aebff ("ocfs2: retry on ENOSPC if sufficient space in truncate log") Link: http://lkml.kernel.org/r/57D91939.6030809@huawei.com Signed-off-by: Joseph Qi Signed-off-by: Jiufei Xue Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds