kernel.git/fs/xfs, branch linux-4.12.y

xfs: XFS_IS_REALTIME_INODE() should be false if no rt device present

2017-09-13T21:17:30Z

commit b31ff3cdf540110da4572e3e29bd172087af65cc upstream. If using a kernel with CONFIG_XFS_RT=y and we set the RHINHERIT flag on a directory in a filesystem that does not have a realtime device and create a new file in that directory, it gets marked as a real time file. When data is written and a fsync is issued, the filesystem attempts to flush a non-existent rt device during the fsync process. This results in a crash dereferencing a null buftarg pointer in xfs_blkdev_issue_flush(): BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: xfs_blkdev_issue_flush+0xd/0x20 ..... Call Trace: xfs_file_fsync+0x188/0x1c0 vfs_fsync_range+0x3b/0xa0 do_fsync+0x3d/0x70 SyS_fsync+0x10/0x20 do_syscall_64+0x4d/0xb0 entry_SYSCALL64_slow_path+0x25/0x25 Setting RT inode flags does not require special privileges so any unprivileged user can cause this oops to occur. To reproduce, confirm kernel is compiled with CONFIG_XFS_RT=y and run: # mkfs.xfs -f /dev/pmem0 # mount /dev/pmem0 /mnt/test # mkdir /mnt/test/foo # xfs_io -c 'chattr +t' /mnt/test/foo # xfs_io -f -c 'pwrite 0 5m' -c fsync /mnt/test/foo/bar Or just run xfstests with MKFS_OPTIONS="-d rtinherit=1" and wait. Kernels built with CONFIG_XFS_RT=n are not exposed to this bug. Fixes: f538d4da8d52 ("[XFS] write barrier support") Signed-off-by: Richard Wareing Signed-off-by: Dave Chinner Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

xfs: Fix leak of discard bio

2017-08-16T20:46:49Z

commit ea7bd56fa309d10a41b1041827a63c0746c47554 upstream. The bio describing discard operation is allocated by __blkdev_issue_discard() which returns us a reference to it. That reference is never released and thus we leak this bio. Drop the bio reference once it completes in xlog_discard_endio(). Fixes: 4560e78f40cb55bd2ea8f1ef4001c5baa88531c7 Signed-off-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman

percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch

2017-07-27T22:10:23Z

commit 104b4e5139fe384431ac11c3b8a6cf4a529edf4a upstream. Currently, percpu_counter_add is a wrapper around __percpu_counter_add which is preempt safe due to explicit calls to preempt_disable. Given how __ prefix is used in percpu related interfaces, the naming unfortunately creates the false sense that __percpu_counter_add is less safe than percpu_counter_add. In terms of context-safety, they're equivalent. The only difference is that the __ version takes a batch parameter. Make this a bit more explicit by just renaming __percpu_counter_add to percpu_counter_add_batch. This patch doesn't cause any functional changes. tj: Minor updates to patch description for clarity. Cosmetic indentation updates. Signed-off-by: Nikolay Borisov Signed-off-by: Tejun Heo Cc: Chris Mason Cc: Josef Bacik Cc: David Sterba Cc: Darrick J. Wong Cc: Jan Kara Cc: Jens Axboe Cc: linux-mm@kvack.org Cc: "David S. Miller" Signed-off-by: Mel Gorman Signed-off-by: Greg Kroah-Hartman

xfs: Don't clear SGID when inheriting ACLs

2017-07-27T22:10:14Z

commit 8ba358756aa08414fa9e65a1a41d28304ed6fd7f upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by calling __xfs_set_acl() instead of xfs_set_acl() when setting up inode in xfs_generic_create(). That prevents SGID bit clearing and mode is properly set by posix_acl_create() anyway. We also reorder arguments of __xfs_set_acl() to match the ordering of xfs_set_acl() to make things consistent. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: Darrick J. Wong CC: linux-xfs@vger.kernel.org Signed-off-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman

Merge tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2017-06-23T19:23:06Z

Pull xfs fixes from Darrick Wong: "I have one more bugfix for you for 4.12-rc7 to fix a disk corruption problem: - don't allow swapon on files on the realtime device, because the swap code will swap pages out to blocks on the data device, thereby corrupting the filesystem" * tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: don't allow bmap on rt files

xfs: don't allow bmap on rt files

2017-06-22T03:27:35Z

bmap returns a dumb LBA address but not the block device that goes with that LBA. Swapfiles don't care about this and will blindly assume that the data volume is the correct blockdev, which is totally bogus for files on the rt subvolume. This results in the swap code doing IOs to arbitrary locations on the data device(!) if the passed in mapping is a realtime file, so just turn off bmap for rt files. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig

Merge tag 'xfs-4.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2017-06-17T08:34:41Z

Pull xfs fix from Darrick Wong: "One more bugfix for you for 4.12-rc6 to fix something that came up in an earlier rc: - Fix some bogus ASSERT failures on CONFIG_SMP=n and CONFIG_XFS_DEBUG=y" * tag 'xfs-4.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: fix spurious spin_is_locked() assert failures on non-smp kernels

xfs: fix spurious spin_is_locked() assert failures on non-smp kernels

2017-06-08T15:23:07Z

The 0-day kernel test robot reports assertion failures on !CONFIG_SMP kernels due to failed spin_is_locked() checks. As it turns out, spin_is_locked() is hardcoded to return zero on !CONFIG_SMP kernels and so this function cannot be relied on to verify spinlock state in this configuration. To avoid this problem, replace the associated asserts with lockdep variants that do the right thing regardless of kernel configuration. Drop the one assert that checks for an unlocked lock as there is no suitable lockdep variant for that case. This moves the spinlock checks from XFS debug code to lockdep, but generally provides the same level of protection. Reported-by: kbuild test robot Signed-off-by: Brian Foster Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

Merge tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2017-06-02T19:29:03Z

Pull XFS fix from Darrick Wong: "I've one more bugfix for you for 4.12-rc4: Fix an unmount hang due to a race in io buffer accounting" * tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: use ->b_state to fix buffer I/O accounting release race

xfs: use ->b_state to fix buffer I/O accounting release race

2017-05-31T15:22:52Z

We've had user reports of unmount hangs in xfs_wait_buftarg() that analysis shows is due to btp->bt_io_count == -1. bt_io_count represents the count of in-flight asynchronous buffers and thus should always be >= 0. xfs_wait_buftarg() waits for this value to stabilize to zero in order to ensure that all untracked (with respect to the lru) buffers have completed I/O processing before unmount proceeds to tear down in-core data structures. The value of -1 implies an I/O accounting decrement race. Indeed, the fact that xfs_buf_ioacct_dec() is called from xfs_buf_rele() (where the buffer lock is no longer held) means that bp->b_flags can be updated from an unsafe context. While a user-level reproducer is currently not available, some intrusive hacks to run racing buffer lookups/ioacct/releases from multiple threads was used to successfully manufacture this problem. Existing callers do not expect to acquire the buffer lock from xfs_buf_rele(). Therefore, we can not safely update ->b_flags from this context. It turns out that we already have separate buffer state bits and associated serialization for dealing with buffer LRU state in the form of ->b_state and ->b_lock. Therefore, replace the _XBF_IN_FLIGHT flag with a ->b_state variant, update the I/O accounting wrappers appropriately and make sure they are used with the correct locking. This ensures that buffer in-flight state can be modified at buffer release time without racing with modifications from a buffer lock holder. Fixes: 9c7504aa72b6 ("xfs: track and serialize in-flight async buffers against unmount") Cc: # v4.8+ Signed-off-by: Brian Foster Reviewed-by: Nikolay Borisov Tested-by: Libor Pechacek Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong