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| * | | | | | Btrfs: fix race leading to BUG_ON when running delalloc for nodatacowFilipe Manana2015-11-091-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we are using the NO_HOLES feature, we have a tiny time window when running delalloc for a nodatacow inode where we can race with a concurrent link or xattr add operation leading to a BUG_ON. This happens because at run_delalloc_nocow() we end up casting a leaf item of type BTRFS_INODE_[REF|EXTREF]_KEY or of type BTRFS_XATTR_ITEM_KEY to a file extent item (struct btrfs_file_extent_item) and then analyse its extent type field, which won't match any of the expected extent types (values BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]) and therefore trigger an explicit BUG_ON(1). The following sequence diagram shows how the race happens when running a no-cow dellaloc range [4K, 8K[ for inode 257 and we have the following neighbour leafs: Leaf X (has N items) Leaf Y [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 EXTENT_DATA 8192), ... ] slot N - 2 slot N - 1 slot 0 (Note the implicit hole for inode 257 regarding the [0, 8K[ range) CPU 1 CPU 2 run_dealloc_nocow() btrfs_lookup_file_extent() --> searches for a key with value (257 EXTENT_DATA 4096) in the fs/subvol tree --> returns us a path with path->nodes[0] == leaf X and path->slots[0] == N because path->slots[0] is >= btrfs_header_nritems(leaf X), it calls btrfs_next_leaf() btrfs_next_leaf() --> releases the path hard link added to our inode, with key (257 INODE_REF 500) added to the end of leaf X, so leaf X now has N + 1 keys --> searches for the key (257 INODE_REF 256), because it was the last key in leaf X before it released the path, with path->keep_locks set to 1 --> ends up at leaf X again and it verifies that the key (257 INODE_REF 256) is no longer the last key in the leaf, so it returns with path->nodes[0] == leaf X and path->slots[0] == N, pointing to the new item with key (257 INODE_REF 500) the loop iteration of run_dealloc_nocow() does not break out the loop and continues because the key referenced in the path at path->nodes[0] and path->slots[0] is for inode 257, its type is < BTRFS_EXTENT_DATA_KEY and its offset (500) is less then our delalloc range's end (8192) the item pointed by the path, an inode reference item, is (incorrectly) interpreted as a file extent item and we get an invalid extent type, leading to the BUG_ON(1): if (extent_type == BTRFS_FILE_EXTENT_REG || extent_type == BTRFS_FILE_EXTENT_PREALLOC) { (...) } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { (...) } else { BUG_ON(1) } The same can happen if a xattr is added concurrently and ends up having a key with an offset smaller then the delalloc's range end. So fix this by skipping keys with a type smaller than BTRFS_EXTENT_DATA_KEY. Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | | | | Btrfs: fix race leading to incorrect item deletion when dropping extentsFilipe Manana2015-11-081-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running a stress test I got the following warning triggered: [191627.672810] ------------[ cut here ]------------ [191627.673949] WARNING: CPU: 8 PID: 8447 at fs/btrfs/file.c:779 __btrfs_drop_extents+0x391/0xa50 [btrfs]() (...) [191627.701485] Call Trace: [191627.702037] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [191627.702992] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [191627.704091] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [191627.705380] [<ffffffffa0664499>] ? __btrfs_drop_extents+0x391/0xa50 [btrfs] [191627.706637] [<ffffffff8104b46d>] warn_slowpath_null+0x1a/0x1c [191627.707789] [<ffffffffa0664499>] __btrfs_drop_extents+0x391/0xa50 [btrfs] [191627.709155] [<ffffffff8115663c>] ? cache_alloc_debugcheck_after.isra.32+0x171/0x1d0 [191627.712444] [<ffffffff81155007>] ? kmemleak_alloc_recursive.constprop.40+0x16/0x18 [191627.714162] [<ffffffffa06570c9>] insert_reserved_file_extent.constprop.40+0x83/0x24e [btrfs] [191627.715887] [<ffffffffa065422b>] ? start_transaction+0x3bb/0x610 [btrfs] [191627.717287] [<ffffffffa065b604>] btrfs_finish_ordered_io+0x273/0x4e2 [btrfs] [191627.728865] [<ffffffffa065b888>] finish_ordered_fn+0x15/0x17 [btrfs] [191627.730045] [<ffffffffa067d688>] normal_work_helper+0x14c/0x32c [btrfs] [191627.731256] [<ffffffffa067d96a>] btrfs_endio_write_helper+0x12/0x14 [btrfs] [191627.732661] [<ffffffff81061119>] process_one_work+0x24c/0x4ae [191627.733822] [<ffffffff810615b0>] worker_thread+0x206/0x2c2 [191627.734857] [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f [191627.736052] [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f [191627.737349] [<ffffffff810669a6>] kthread+0xef/0xf7 [191627.738267] [<ffffffff810f3b3a>] ? time_hardirqs_on+0x15/0x28 [191627.739330] [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad [191627.741976] [<ffffffff81465592>] ret_from_fork+0x42/0x70 [191627.743080] [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad [191627.744206] ---[ end trace bbfddacb7aaada8d ]--- $ cat -n fs/btrfs/file.c 691 int __btrfs_drop_extents(struct btrfs_trans_handle *trans, (...) 758 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 759 if (key.objectid > ino || 760 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end) 761 break; 762 763 fi = btrfs_item_ptr(leaf, path->slots[0], 764 struct btrfs_file_extent_item); 765 extent_type = btrfs_file_extent_type(leaf, fi); 766 767 if (extent_type == BTRFS_FILE_EXTENT_REG || 768 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { (...) 774 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { (...) 778 } else { 779 WARN_ON(1); 780 extent_end = search_start; 781 } (...) This happened because the item we were processing did not match a file extent item (its key type != BTRFS_EXTENT_DATA_KEY), and even on this case we cast the item to a struct btrfs_file_extent_item pointer and then find a type field value that does not match any of the expected values (BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]). This scenario happens due to a tiny time window where a race can happen as exemplified below. For example, consider the following scenario where we're using the NO_HOLES feature and we have the following two neighbour leafs: Leaf X (has N items) Leaf Y [ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 EXTENT_DATA 8192), ... ] slot N - 2 slot N - 1 slot 0 Our inode 257 has an implicit hole in the range [0, 8K[ (implicit rather than explicit because NO_HOLES is enabled). Now if our inode has an ordered extent for the range [4K, 8K[ that is finishing, the following can happen: CPU 1 CPU 2 btrfs_finish_ordered_io() insert_reserved_file_extent() __btrfs_drop_extents() Searches for the key (257 EXTENT_DATA 4096) through btrfs_lookup_file_extent() Key not found and we get a path where path->nodes[0] == leaf X and path->slots[0] == N Because path->slots[0] is >= btrfs_header_nritems(leaf X), we call btrfs_next_leaf() btrfs_next_leaf() releases the path inserts key (257 INODE_REF 4096) at the end of leaf X, leaf X now has N + 1 keys, and the new key is at slot N btrfs_next_leaf() searches for key (257 INODE_REF 256), with path->keep_locks set to 1, because it was the last key it saw in leaf X finds it in leaf X again and notices it's no longer the last key of the leaf, so it returns 0 with path->nodes[0] == leaf X and path->slots[0] == N (which is now < btrfs_header_nritems(leaf X)), pointing to the new key (257 INODE_REF 4096) __btrfs_drop_extents() casts the item at path->nodes[0], slot path->slots[0], to a struct btrfs_file_extent_item - it does not skip keys for the target inode with a type less than BTRFS_EXTENT_DATA_KEY (BTRFS_INODE_REF_KEY < BTRFS_EXTENT_DATA_KEY) sees a bogus value for the type field triggering the WARN_ON in the trace shown above, and sets extent_end = search_start (4096) does the if-then-else logic to fixup 0 length extent items created by a past bug from hole punching: if (extent_end == key.offset && extent_end >= search_start) goto delete_extent_item; that evaluates to true and it ends up deleting the key pointed to by path->slots[0], (257 INODE_REF 4096), from leaf X The same could happen for example for a xattr that ends up having a key with an offset value that matches search_start (very unlikely but not impossible). So fix this by ensuring that keys smaller than BTRFS_EXTENT_DATA_KEY are skipped, never casted to struct btrfs_file_extent_item and never deleted by accident. Also protect against the unexpected case of getting a key for a lower inode number by skipping that key and issuing a warning. Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | | | | Btrfs: fix sleeping inside atomic context in qgroup rescan workerFilipe Manana2015-11-051-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are holding a btree path with spinning locks and then we attempt to clone an extent buffer, which calls kmem_cache_alloc() and this function can sleep, causing the following trace to be reported on a debug kernel: [107118.218536] BUG: sleeping function called from invalid context at mm/slab.c:2871 [107118.224110] in_atomic(): 1, irqs_disabled(): 0, pid: 19148, name: kworker/u32:3 [107118.226120] INFO: lockdep is turned off. [107118.226843] Preemption disabled at:[<ffffffffa05ffa22>] btrfs_clear_lock_blocking_rw+0x96/0xea [btrfs] [107118.229175] CPU: 3 PID: 19148 Comm: kworker/u32:3 Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [107118.231326] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [107118.233687] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs] [107118.236835] 0000000000000000 ffff880424bf3b78 ffffffff812566f4 0000000000000000 [107118.238369] ffff880424bf3ba0 ffffffff81070664 ffffffff817f1cd5 0000000000000b37 [107118.239769] 0000000000000000 ffff880424bf3bc8 ffffffff8107070a 0000000000008850 [107118.241244] Call Trace: [107118.241729] [<ffffffff812566f4>] dump_stack+0x4e/0x79 [107118.242602] [<ffffffff81070664>] ___might_sleep+0x23a/0x241 [107118.243586] [<ffffffff8107070a>] __might_sleep+0x9f/0xa6 [107118.244532] [<ffffffff8115af70>] cache_alloc_debugcheck_before+0x25/0x36 [107118.245939] [<ffffffff8115d52b>] kmem_cache_alloc+0x50/0x215 [107118.246930] [<ffffffffa05e627e>] __alloc_extent_buffer+0x2a/0x11f [btrfs] [107118.248121] [<ffffffffa05ecb1a>] btrfs_clone_extent_buffer+0x3d/0xdd [btrfs] [107118.249451] [<ffffffffa06239ea>] btrfs_qgroup_rescan_worker+0x16d/0x434 [btrfs] [107118.250755] [<ffffffff81087481>] ? arch_local_irq_save+0x9/0xc [107118.251754] [<ffffffffa05f7952>] normal_work_helper+0x14c/0x32a [btrfs] [107118.252899] [<ffffffffa05f7952>] ? normal_work_helper+0x14c/0x32a [btrfs] [107118.254195] [<ffffffffa05f7c82>] btrfs_qgroup_rescan_helper+0x12/0x14 [btrfs] [107118.255436] [<ffffffff81063b23>] process_one_work+0x24a/0x4ac [107118.263690] [<ffffffff81064285>] worker_thread+0x206/0x2c2 [107118.264888] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb [107118.267413] [<ffffffff8106904d>] kthread+0xef/0xf7 [107118.268417] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 [107118.269505] [<ffffffff8147d10f>] ret_from_fork+0x3f/0x70 [107118.270491] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 So just use blocking locks for our path to solve this. This fixes the patch titled: "btrfs: qgroup: Don't copy extent buffer to do qgroup rescan" Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | | | | Btrfs: fix race waiting for qgroup rescan workerFilipe Manana2015-11-051-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We were initializing the completion (fs_info->qgroup_rescan_completion) object after releasing the qgroup rescan lock, which gives a small time window for a rescan waiter to not actually wait for the rescan worker to finish. Example: CPU 1 CPU 2 fs_info->qgroup_rescan_completion->done is 0 btrfs_qgroup_rescan_worker() complete_all(&fs_info->qgroup_rescan_completion) sets fs_info->qgroup_rescan_completion->done to UINT_MAX / 2 ... do some other stuff .... qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) set flag BTRFS_QGROUP_STATUS_FLAG_RESCAN in fs_info->qgroup_flags mutex_unlock(&fs_info->qgroup_rescan_lock) btrfs_qgroup_wait_for_completion() mutex_lock(&fs_info->qgroup_rescan_lock) sees flag BTRFS_QGROUP_STATUS_FLAG_RESCAN in fs_info->qgroup_flags mutex_unlock(&fs_info->qgroup_rescan_lock) wait_for_completion_interruptible( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_completion->done is > 0 so it returns immediately init_completion(&fs_info->qgroup_rescan_completion) sets fs_info->qgroup_rescan_completion->done to 0 So fix this by initializing the completion object while holding the mutex fs_info->qgroup_rescan_lock. Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | | | | btrfs: qgroup: exit the rescan worker during umountJustin Maggard2015-11-052-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I was hitting a consistent NULL pointer dereference during shutdown that showed the trace running through end_workqueue_bio(). I traced it back to the endio_meta_workers workqueue being poked after it had already been destroyed. Eventually I found that the root cause was a qgroup rescan that was still in progress while we were stopping all the btrfs workers. Currently we explicitly pause balance and scrub operations in close_ctree(), but we do nothing to stop the qgroup rescan. We should probably be doing the same for qgroup rescan, but that's a much larger change. This small change is good enough to allow me to unmount without crashing. Signed-off-by: Justin Maggard <jmaggard@netgear.com> Reviewed-by: Filipe Manana <fdmanana@suse.com>
| * | | | | | Btrfs: fix extent accounting for partial direct IO writesFilipe Manana2015-11-051-15/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing a write using direct IO we can end up not doing the whole write operation using the direct IO path, in that case we fallback to a buffered write to do the remaining IO. This happens for example if the range we are writing to contains a compressed extent. When we do a partial write and fallback to buffered IO, due to the existence of a compressed extent for example, we end up not adjusting the outstanding extents counter of our inode which ends up getting decremented twice, once by the DIO ordered extent for the partial write and once again by btrfs_direct_IO(), resulting in an arithmetic underflow at extent-tree.c:drop_outstanding_extent(). For example if we have: extents [ prealloc extent ] [ compressed extent ] offsets A B C D E and at the moment our inode's outstanding extents counter is 0, if we do a direct IO write against the range [B, D[ (which has a length smaller than 128Mb), we end up bumping our inode's outstanding extents counter to 1, we create a DIO ordered extent for the range [B, C[ and then fallback to a buffered write for the range [C, D[. The direct IO handler (inode.c:btrfs_direct_IO()) decrements the outstanding extents counter by 1, leaving it with a value of 0, through a call to btrfs_delalloc_release_space() and then shortly after the DIO ordered extent finishes and calls btrfs_delalloc_release_metadata() which ends up to attempt to decrement the inode's outstanding extents counter by 1, resulting in an assertion failure at drop_outstanding_extent() because the operation would result in an arithmetic underflow (0 - 1). This produces the following trace: [125471.336838] BTRFS: assertion failed: BTRFS_I(inode)->outstanding_extents >= num_extents, file: fs/btrfs/extent-tree.c, line: 5526 [125471.338844] ------------[ cut here ]------------ [125471.340745] kernel BUG at fs/btrfs/ctree.h:4173! [125471.340745] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [125471.340745] Modules linked in: btrfs f2fs xfs libcrc32c dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc acpi_cpufreq psmouse i2c_piix4 parport pcspkr serio_raw microcode processor evdev i2c_core button ext4 crc16 jbd2 mbcache sd_mod sg sr_mod cdrom ata_generic virtio_scsi ata_piix virtio_pci virtio_ring floppy libata virtio e1000 scsi_mod [last unloaded: btrfs] [125471.340745] CPU: 10 PID: 23649 Comm: kworker/u32:1 Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [125471.340745] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [125471.340745] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [125471.340745] task: ffff8804244fcf80 ti: ffff88040a118000 task.ti: ffff88040a118000 [125471.340745] RIP: 0010:[<ffffffffa0550da1>] [<ffffffffa0550da1>] assfail.constprop.46+0x1e/0x20 [btrfs] [125471.340745] RSP: 0018:ffff88040a11bc78 EFLAGS: 00010296 [125471.340745] RAX: 0000000000000075 RBX: 0000000000005000 RCX: 0000000000000000 [125471.340745] RDX: ffffffff81098f93 RSI: ffffffff8147c619 RDI: 00000000ffffffff [125471.340745] RBP: ffff88040a11bc78 R08: 0000000000000001 R09: 0000000000000000 [125471.340745] R10: ffff88040a11bc08 R11: ffffffff81651000 R12: ffff8803efb4a000 [125471.340745] R13: ffff8803efb4a000 R14: 0000000000000000 R15: ffff8802f8e33c88 [125471.340745] FS: 0000000000000000(0000) GS:ffff88043dd40000(0000) knlGS:0000000000000000 [125471.340745] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [125471.340745] CR2: 00007fae7ca86095 CR3: 0000000001a0b000 CR4: 00000000000006e0 [125471.340745] Stack: [125471.340745] ffff88040a11bc88 ffffffffa04ca0cd ffff88040a11bcc8 ffffffffa04ceeb1 [125471.340745] ffff8802f8e33940 ffff8802c93eadb0 ffff8802f8e0bf50 ffff8803efb4a000 [125471.340745] 0000000000000000 ffff8802f8e33c88 ffff88040a11bd38 ffffffffa04eccfa [125471.340745] Call Trace: [125471.340745] [<ffffffffa04ca0cd>] drop_outstanding_extent+0x3d/0x6d [btrfs] [125471.340745] [<ffffffffa04ceeb1>] btrfs_delalloc_release_metadata+0x51/0xdd [btrfs] [125471.340745] [<ffffffffa04eccfa>] btrfs_finish_ordered_io+0x420/0x4eb [btrfs] [125471.340745] [<ffffffffa04ecdda>] finish_ordered_fn+0x15/0x17 [btrfs] [125471.340745] [<ffffffffa050e6e8>] normal_work_helper+0x14c/0x32a [btrfs] [125471.340745] [<ffffffffa050e9c8>] btrfs_endio_write_helper+0x12/0x14 [btrfs] [125471.340745] [<ffffffff81063b23>] process_one_work+0x24a/0x4ac [125471.340745] [<ffffffff81064285>] worker_thread+0x206/0x2c2 [125471.340745] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb [125471.340745] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb [125471.340745] [<ffffffff8106904d>] kthread+0xef/0xf7 [125471.340745] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 [125471.340745] [<ffffffff8147d10f>] ret_from_fork+0x3f/0x70 [125471.340745] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 [125471.340745] Code: a5 55 a0 48 89 e5 e8 42 50 bc e0 0f 0b 55 89 f1 48 c7 c2 f0 a8 55 a0 48 89 fe 31 c0 48 c7 c7 14 aa 55 a0 48 89 e5 e8 22 50 bc e0 <0f> 0b 0f 1f 44 00 00 55 31 c9 ba 18 00 00 00 48 89 e5 41 56 41 [125471.340745] RIP [<ffffffffa0550da1>] assfail.constprop.46+0x1e/0x20 [btrfs] [125471.340745] RSP <ffff88040a11bc78> [125471.539620] ---[ end trace 144259f7838b4aa4 ]--- So fix this by ensuring we adjust the outstanding extents counter when we do the fallback just like we do for the case where the whole write can be done through the direct IO path. We were also adjusting the outstanding extents counter by a constant value of 1, which is incorrect because we were ignorning that we account extents in BTRFS_MAX_EXTENT_SIZE units, o fix that as well. The following test case for fstests reproduces this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_xfs_io_command "falloc" rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount "-o compress" # Create a compressed extent covering the range [700K, 800K[. $XFS_IO_PROG -f -s -c "pwrite -S 0xaa -b 100K 700K 100K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Create prealloc extent covering the range [600K, 700K[. $XFS_IO_PROG -c "falloc 600K 100K" $SCRATCH_MNT/foo # Write 80K of data to the range [640K, 720K[ using direct IO. This # range covers both the prealloc extent and the compressed extent. # Because there's a compressed extent in the range we are writing to, # the DIO write code path ends up only writing the first 60k of data, # which goes to the prealloc extent, and then falls back to buffered IO # for writing the remaining 20K of data - because that remaining data # maps to a file range containing a compressed extent. # When falling back to buffered IO, we used to trigger an assertion when # releasing reserved space due to bad accounting of the inode's # outstanding extents counter, which was set to 1 but we ended up # decrementing it by 1 twice, once through the ordered extent for the # 60K of data we wrote using direct IO, and once through the main direct # IO handler (inode.cbtrfs_direct_IO()) because the direct IO write # wrote less than 80K of data (60K). $XFS_IO_PROG -d -c "pwrite -S 0xbb -b 80K 640K 80K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now similar test as above but for very large write operations. This # triggers special cases for an inode's outstanding extents accounting, # as internally btrfs logically splits extents into 128Mb units. $XFS_IO_PROG -f -s \ -c "pwrite -S 0xaa -b 128M 258M 128M" \ -c "falloc 0 258M" \ $SCRATCH_MNT/bar | _filter_xfs_io $XFS_IO_PROG -d -c "pwrite -S 0xbb -b 256M 3M 256M" $SCRATCH_MNT/bar \ | _filter_xfs_io # Now verify the file contents are correct and that they are the same # even after unmounting and mounting the fs again (or evicting the page # cache). # # For file foo, all bytes in the range [0, 640K[ must have a value of # 0x00, all bytes in the range [640K, 720K[ must have a value of 0xbb # and all bytes in the range [720K, 800K[ must have a value of 0xaa. # # For file bar, all bytes in the range [0, 3M[ must havea value of 0x00, # all bytes in the range [3M, 259M[ must have a value of 0xbb and all # bytes in the range [259M, 386M[ must have a value of 0xaa. # echo "File digests before remounting the file system:" md5sum $SCRATCH_MNT/foo | _filter_scratch md5sum $SCRATCH_MNT/bar | _filter_scratch _scratch_remount echo "File digests after remounting the file system:" md5sum $SCRATCH_MNT/foo | _filter_scratch md5sum $SCRATCH_MNT/bar | _filter_scratch status=0 exit Fixes: e1cbbfa5f5aa ("Btrfs: fix outstanding_extents accounting in DIO") Fixes: 3e05bde8c3c2 ("Btrfs: only adjust outstanding_extents when we do a short write") Signed-off-by: Filipe Manana <fdmanana@suse.com>
* | | | | | | Merge branch 'for-linus' of ↵Linus Torvalds2015-11-137-66/+161
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client Pull Ceph updates from Sage Weil: "There are several patches from Ilya fixing RBD allocation lifecycle issues, a series adding a nocephx_sign_messages option (and associated bug fixes/cleanups), several patches from Zheng improving the (directory) fsync behavior, a big improvement in IO for direct-io requests when striping is enabled from Caifeng, and several other small fixes and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: libceph: clear msg->con in ceph_msg_release() only libceph: add nocephx_sign_messages option libceph: stop duplicating client fields in messenger libceph: drop authorizer check from cephx msg signing routines libceph: msg signing callouts don't need con argument libceph: evaluate osd_req_op_data() arguments only once ceph: make fsync() wait unsafe requests that created/modified inode ceph: add request to i_unsafe_dirops when getting unsafe reply libceph: introduce ceph_x_authorizer_cleanup() ceph: don't invalidate page cache when inode is no longer used rbd: remove duplicate calls to rbd_dev_mapping_clear() rbd: set device_type::release instead of device::release rbd: don't free rbd_dev outside of the release callback rbd: return -ENOMEM instead of pool id if rbd_dev_create() fails libceph: use local variable cursor instead of &msg->cursor libceph: remove con argument in handle_reply() ceph: combine as many iovec as possile into one OSD request ceph: fix message length computation ceph: fix a comment typo rbd: drop null test before destroy functions
| * | | | | | | libceph: msg signing callouts don't need con argumentIlya Dryomov2015-11-021-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can use msg->con instead - at the point we sign an outgoing message or check the signature on the incoming one, msg->con is always set. We wouldn't know how to sign a message without an associated session (i.e. msg->con == NULL) and being able to sign a message using an explicitly provided authorizer is of no use. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
| * | | | | | | ceph: make fsync() wait unsafe requests that created/modified inodeYan, Zheng2015-11-025-37/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we get a unsafe reply for request that created/modified inode, add the unsafe request to a list in the newly created/modified inode. So we can make fsync() wait these unsafe requests. Signed-off-by: Yan, Zheng <zyan@redhat.com>
| * | | | | | | ceph: add request to i_unsafe_dirops when getting unsafe replyYan, Zheng2015-11-021-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously we add request to i_unsafe_dirops when registering request. So ceph_fsync() also waits for imcomplete requests. This is unnecessary, ceph_fsync() only needs to wait unsafe requests. Signed-off-by: Yan, Zheng <zyan@redhat.com>
| * | | | | | | ceph: don't invalidate page cache when inode is no longer usedYan, Zheng2015-11-022-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ceph_check_caps() invalidate page cache when inode is not used by any open file. This behaviour is not friendly for workload that repeatly read files. Signed-off-by: Yan, Zheng <zyan@redhat.com>
| * | | | | | | ceph: combine as many iovec as possile into one OSD requestZhu, Caifeng2015-11-021-10/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both ceph_sync_direct_write and ceph_sync_read iterate iovec elements one by one, send one OSD request for each iovec. This is sub-optimal, We can combine serveral iovec into one page vector, and send an OSD request for the whole page vector. Signed-off-by: Zhu, Caifeng <zhucaifeng@unissoft-nj.com> Signed-off-by: Yan, Zheng <zyan@redhat.com>
| * | | | | | | ceph: fix message length computationArnd Bergmann2015-11-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | create_request_message() computes the maximum length of a message, but uses the wrong type for the time stamp: sizeof(struct timespec) may be 8 or 16 depending on the architecture, while sizeof(struct ceph_timespec) is always 8, and that is what gets put into the message. Found while auditing the uses of timespec for y2038 problems. Fixes: b8e69066d8af ("ceph: include time stamp in every MDS request") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yan, Zheng <zyan@redhat.com>
| * | | | | | | ceph: fix a comment typoGeliang Tang2015-11-021-1/+1
| | |/ / / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Yan, Zheng <zyan@redhat.com>
* | | | | | | Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2015-11-122-4/+15
|\ \ \ \ \ \ \ | |_|_|/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull misc block fixes from Jens Axboe: "Stuff that got collected after the merge window opened. This contains: - NVMe: - Fix for non-striped transfer size setting for NVMe from Sathyavathi. - (Some) support for the weird Apple nvme controller in the macbooks. From Stephan Günther. - The error value leak for dax from Al. - A few minor blk-mq tweaks from me. - Add the new linux-block@vger.kernel.org mailing list to the MAINTAINERS file. - Discard fix for brd, from Jan. - A kerneldoc warning for block core from Randy. - An older fix from Vivek, converting a WARN_ON() to a rate limited printk when a device is hot removed with dirty inodes" * 'for-linus' of git://git.kernel.dk/linux-block: block: don't hardcode blk_qc_t -> tag mask dax_io(): don't let non-error value escape via retval instead of EFAULT block: fix blk-core.c kernel-doc warning fs/block_dev.c: Remove WARN_ON() when inode writeback fails NVMe: add support for Apple NVMe controller NVMe: use split lo_hi_{read,write}q blk-mq: mark __blk_mq_complete_request() static MAINTAINERS: add reference to new linux-block list NVMe: Increase the max transfer size when mdts is 0 brd: Refuse improperly aligned discard requests
| * | | | | | dax_io(): don't let non-error value escape via retval instead of EFAULTAl Viro2015-11-111-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | fs/block_dev.c: Remove WARN_ON() when inode writeback failsVivek Goyal2015-11-111-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a block device is hot removed and later last reference to device is put, we try to writeback the dirty inode. But device is gone and that writeback fails. Currently we do a WARN_ON() which does not seem to be the right thing. Convert it to a ratelimited kernel warning. Reported-by: Andi Kleen <andi@firstfloor.org> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> [jmoyer@redhat.com: get rid of unnecessary name initialization, 80 cols] Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | | | | | | Merge tag 'xfs-for-linus-4.4' of ↵Linus Torvalds2015-11-1162-411/+994
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs updates from Dave Chinner: "There is nothing really major here - the only significant addition is the per-mount operation statistics infrastructure. Otherwises there's various ACL, xattr, DAX, AIO and logging fixes, and a smattering of small cleanups and fixes elsewhere. Summary: - per-mount operational statistics in sysfs - fixes for concurrent aio append write submission - various logging fixes - detection of zeroed logs and invalid log sequence numbers on v5 filesystems - memory allocation failure message improvements - a bunch of xattr/ACL fixes - fdatasync optimisation - miscellaneous other fixes and cleanups" * tag 'xfs-for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (39 commits) xfs: give all workqueues rescuer threads xfs: fix log recovery op header validation assert xfs: Fix error path in xfs_get_acl xfs: optimise away log forces on timestamp updates for fdatasync xfs: don't leak uuid table on rmmod xfs: invalidate cached acl if set via ioctl xfs: Plug memory leak in xfs_attrmulti_attr_set xfs: Validate the length of on-disk ACLs xfs: invalidate cached acl if set directly via xattr xfs: xfs_filemap_pmd_fault treats read faults as write faults xfs: add ->pfn_mkwrite support for DAX xfs: DAX does not use IO completion callbacks xfs: Don't use unwritten extents for DAX xfs: introduce BMAPI_ZERO for allocating zeroed extents xfs: fix inode size update overflow in xfs_map_direct() xfs: clear PF_NOFREEZE for xfsaild kthread xfs: fix an error code in xfs_fs_fill_super() xfs: stats are no longer dependent on CONFIG_PROC_FS xfs: simplify /proc teardown & error handling xfs: per-filesystem stats counter implementation ...
| * \ \ \ \ \ \ Merge branch 'xfs-misc-fixes-for-4.4-3' into for-nextDave Chinner2015-11-104-5/+6
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| | * | | | | | | xfs: give all workqueues rescuer threadsChris Mason2015-11-101-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're consistently hitting deadlocks here with XFS on recent kernels. After some digging through the crash files, it looks like everyone in the system is waiting for XFS to reclaim memory. Something like this: PID: 2733434 TASK: ffff8808cd242800 CPU: 19 COMMAND: "java" #0 [ffff880019c53588] __schedule at ffffffff818c4df2 #1 [ffff880019c535d8] schedule at ffffffff818c5517 #2 [ffff880019c535f8] _xfs_log_force_lsn at ffffffff81316348 #3 [ffff880019c53688] xfs_log_force_lsn at ffffffff813164fb #4 [ffff880019c536b8] xfs_iunpin_wait at ffffffff8130835e #5 [ffff880019c53728] xfs_reclaim_inode at ffffffff812fd453 #6 [ffff880019c53778] xfs_reclaim_inodes_ag at ffffffff812fd8c7 #7 [ffff880019c53928] xfs_reclaim_inodes_nr at ffffffff812fe433 #8 [ffff880019c53958] xfs_fs_free_cached_objects at ffffffff8130d3b9 #9 [ffff880019c53968] super_cache_scan at ffffffff811a6f73 #10 [ffff880019c539c8] shrink_slab at ffffffff811460e6 #11 [ffff880019c53aa8] shrink_zone at ffffffff8114a53f #12 [ffff880019c53b48] do_try_to_free_pages at ffffffff8114a8ba #13 [ffff880019c53be8] try_to_free_pages at ffffffff8114ad5a #14 [ffff880019c53c78] __alloc_pages_nodemask at ffffffff8113e1b8 #15 [ffff880019c53d88] alloc_kmem_pages_node at ffffffff8113e671 #16 [ffff880019c53dd8] copy_process at ffffffff8104f781 #17 [ffff880019c53ec8] do_fork at ffffffff8105129c #18 [ffff880019c53f38] sys_clone at ffffffff810515b6 #19 [ffff880019c53f48] stub_clone at ffffffff818c8e4d xfs_log_force_lsn is waiting for logs to get cleaned, which is waiting for IO, which is waiting for workers to complete the IO which is waiting for worker threads that don't exist yet: PID: 2752451 TASK: ffff880bd6bdda00 CPU: 37 COMMAND: "kworker/37:1" #0 [ffff8808d20abbb0] __schedule at ffffffff818c4df2 #1 [ffff8808d20abc00] schedule at ffffffff818c5517 #2 [ffff8808d20abc20] schedule_timeout at ffffffff818c7c6c #3 [ffff8808d20abcc0] wait_for_completion_killable at ffffffff818c6495 #4 [ffff8808d20abd30] kthread_create_on_node at ffffffff8106ec82 #5 [ffff8808d20abdf0] create_worker at ffffffff8106752f #6 [ffff8808d20abe40] worker_thread at ffffffff810699be #7 [ffff8808d20abec0] kthread at ffffffff8106ef59 #8 [ffff8808d20abf50] ret_from_fork at ffffffff818c8ac8 I think we should be using WQ_MEM_RECLAIM to make sure this thread pool makes progress when we're not able to allocate new workers. [dchinner: make all workqueues WQ_MEM_RECLAIM] Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | xfs: fix log recovery op header validation assertBrian Foster2015-11-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 89cebc84 ("xfs: validate transaction header length on log recovery") added additional validation of the on-disk op header length to protect from buffer overflow during log recovery. It accounts for the fact that the transaction header can be split across multiple op headers. It added an assert for when this occurs that verifies the length of the second part of a split transaction header is less than a full transaction header. In other words, it expects that the first op header of a split transaction header includes at least some portion of the transaction header. This expectation is not always valid as a zero-length op header can exist for the first op header of a split transaction header (see xlog_recover_add_to_trans() for details). This means that the second op header can have a valid, full length transaction header and thus the full header is copied in xlog_recover_add_to_cont_trans(). Fix the assert in xlog_recover_add_to_cont_trans() to handle this case correctly and require that the op header length is less than or equal to a full transaction header. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | xfs: Fix error path in xfs_get_aclAndreas Gruenbacher2015-11-102-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Error codes from xfs_attr_get other than -ENOATTR were not properly reported. Fix that. In addition, the declaration of struct xfs_inode in xfs_acl.h isn't needed. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| * | | | | | | | Merge branch 'xfs-dax-updates' into for-nextDave Chinner2015-11-0312-65/+230
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| | * | | | | | | | xfs: xfs_filemap_pmd_fault treats read faults as write faultsDave Chinner2015-11-031-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code initially committed didn't have the same checks for write faults as the dax_pmd_fault code and hence treats all faults as write faults. We can get read faults through this path because they is no pmd_mkwrite path for write faults similar to the normal page fault path. Hence we need to ensure that we only do c/mtime updates on write faults, and freeze protection is unnecessary for read faults. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: add ->pfn_mkwrite support for DAXDave Chinner2015-11-032-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ->pfn_mkwrite support is needed so that when a page with allocated backing store takes a write fault we can check that the fault has not raced with a truncate and is pointing to a region beyond the current end of file. This also allows us to update the timestamp on the inode, too, which fixes a generic/080 failure. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: DAX does not use IO completion callbacksDave Chinner2015-11-033-43/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For DAX, we are now doing block zeroing during allocation. This means we no longer need a special DAX fault IO completion callback to do unwritten extent conversion. Because mmap never extends the file size (it SEGVs the process) we don't need a callback to update the file size, either. Hence we can remove the completion callbacks from the __dax_fault and __dax_mkwrite calls. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: Don't use unwritten extents for DAXDave Chinner2015-11-033-6/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DAX has a page fault serialisation problem with block allocation. Because it allows concurrent page faults and does not have a page lock to serialise faults to the same page, it can get two concurrent faults to the page that race. When two read faults race, this isn't a huge problem as the data underlying the page is not changing and so "detect and drop" works just fine. The issues are to do with write faults. When two write faults occur, we serialise block allocation in get_blocks() so only one faul will allocate the extent. It will, however, be marked as an unwritten extent, and that is where the problem lies - the DAX fault code cannot differentiate between a block that was just allocated and a block that was preallocated and needs zeroing. The result is that both write faults end up zeroing the block and attempting to convert it back to written. The problem is that the first fault can zero and convert before the second fault starts zeroing, resulting in the zeroing for the second fault overwriting the data that the first fault wrote with zeros. The second fault then attempts to convert the unwritten extent, which is then a no-op because it's already written. Data loss occurs as a result of this race. Because there is no sane locking construct in the page fault code that we can use for serialisation across the page faults, we need to ensure block allocation and zeroing occurs atomically in the filesystem. This means we can still take concurrent page faults and the only time they will serialise is in the filesystem mapping/allocation callback. The page fault code will always see written, initialised extents, so we will be able to remove the unwritten extent handling from the DAX code when all filesystems are converted. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: introduce BMAPI_ZERO for allocating zeroed extentsDave Chinner2015-11-036-8/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To enable DAX to do atomic allocation of zeroed extents, we need to drive the block zeroing deep into the allocator. Because xfs_bmapi_write() can return merged extents on allocation that were only partially allocated (i.e. requested range spans allocated and hole regions, allocation into the hole was contiguous), we cannot zero the extent returned from xfs_bmapi_write() as that can overwrite existing data with zeros. Hence we have to drive the extent zeroing into the allocation code, prior to where we merge the extents into the BMBT and return the resultant map. This means we need to propagate this need down to the xfs_alloc_vextent() and issue the block zeroing at this point. While this functionality is being introduced for DAX, there is no reason why it is specific to DAX - we can per-zero blocks during the allocation transaction on any type of device. It's just slow (and usually slower than unwritten allocation and conversion) on traditional block devices so doesn't tend to get used. We can, however, hook hardware zeroing optimisations via sb_issue_zeroout() to this operation, so it may be useful in future and hence the "allocate zeroed blocks" API needs to be implementation neutral. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: fix inode size update overflow in xfs_map_direct()Dave Chinner2015-11-033-9/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both direct IO and DAX pass an offset and count into get_blocks that will overflow a s64 variable when an IO goes into the last supported block in a file (i.e. at offset 2^63 - 1FSB bytes). This can be seen from the tracing: xfs_get_blocks_alloc: [...] offset 0x7ffffffffffff000 count 4096 xfs_gbmap_direct: [...] offset 0x7ffffffffffff000 count 4096 xfs_gbmap_direct_none:[...] offset 0x7ffffffffffff000 count 4096 0x7ffffffffffff000 + 4096 = 0x8000000000000000, and hence that overflows the s64 offset and we fail to detect the need for a filesize update and an ioend is not allocated. This is *mostly* avoided for direct IO because such extending IOs occur with full block allocation, and so the "IS_UNWRITTEN()" check still evaluates as true and we get an ioend that way. However, doing single sector extending IOs to this last block will expose the fact that file size updates will not occur after the first allocating direct IO as the overflow will then be exposed. There is one further complexity: the DAX page fault path also exposes the same issue in block allocation. However, page faults cannot extend the file size, so in this case we want to allocate the block but do not want to allocate an ioend to enable file size update at IO completion. Hence we now need to distinguish between the direct IO patch allocation and dax fault path allocation to avoid leaking ioend structures. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| * | | | | | | | | Merge branch 'xfs-misc-fixes-for-4.4-2' into for-nextDave Chinner2015-11-0314-16/+101
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| | * | | | | | | | xfs: optimise away log forces on timestamp updates for fdatasyncDave Chinner2015-11-035-5/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xfs: timestamp updates cause excessive fdatasync log traffic Sage Weil reported that a ceph test workload was writing to the log on every fdatasync during an overwrite workload. Event tracing showed that the only metadata modification being made was the timestamp updates during the write(2) syscall, but fdatasync(2) is supposed to ignore them. The key observation was that the transactions in the log all looked like this: INODE: #regs: 4 ino: 0x8b flags: 0x45 dsize: 32 And contained a flags field of 0x45 or 0x85, and had data and attribute forks following the inode core. This means that the timestamp updates were triggering dirty relogging of previously logged parts of the inode that hadn't yet been flushed back to disk. There are two parts to this problem. The first is that XFS relogs dirty regions in subsequent transactions, so it carries around the fields that have been dirtied since the last time the inode was written back to disk, not since the last time the inode was forced into the log. The second part is that on v5 filesystems, the inode change count update during inode dirtying also sets the XFS_ILOG_CORE flag, so on v5 filesystems this makes a timestamp update dirty the entire inode. As a result when fdatasync is run, it looks at the dirty fields in the inode, and sees more than just the timestamp flag, even though the only metadata change since the last fdatasync was just the timestamps. Hence we force the log on every subsequent fdatasync even though it is not needed. To fix this, add a new field to the inode log item that tracks changes since the last time fsync/fdatasync forced the log to flush the changes to the journal. This flag is updated when we dirty the inode, but we do it before updating the change count so it does not carry the "core dirty" flag from timestamp updates. The fields are zeroed when the inode is marked clean (due to writeback/freeing) or when an fsync/datasync forces the log. Hence if we only dirty the timestamps on the inode between fsync/fdatasync calls, the fdatasync will not trigger another log force. Over 100 runs of the test program: Ext4 baseline: runtime: 1.63s +/- 0.24s avg lat: 1.59ms +/- 0.24ms iops: ~2000 XFS, vanilla kernel: runtime: 2.45s +/- 0.18s avg lat: 2.39ms +/- 0.18ms log forces: ~400/s iops: ~1000 XFS, patched kernel: runtime: 1.49s +/- 0.26s avg lat: 1.46ms +/- 0.25ms log forces: ~30/s iops: ~1500 Reported-by: Sage Weil <sage@redhat.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: don't leak uuid table on rmmodDarrick J. Wong2015-11-033-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't leak the UUID table when the module is unloaded. (Found with kmemleak.) Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: invalidate cached acl if set via ioctlAndreas Gruenbacher2015-11-033-15/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Setting or removing the "SGI_ACL_[FILE|DEFAULT]" attributes via the XFS_IOC_ATTRMULTI_BY_HANDLE ioctl completely bypasses the POSIX ACL infrastructure, like setting the "trusted.SGI_ACL_[FILE|DEFAULT]" xattrs did until commit 6caa1056. Similar to that commit, invalidate cached acls when setting/removing them via the ioctl as well. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: Plug memory leak in xfs_attrmulti_attr_setAndreas Gruenbacher2015-11-031-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When setting attributes via XFS_IOC_ATTRMULTI_BY_HANDLE, the user-space buffer is copied into a new kernel-space buffer via memdup_user; that buffer then isn't freed. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: Validate the length of on-disk ACLsAndreas Gruenbacher2015-11-032-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In xfs_acl_from_disk, instead of trusting that xfs_acl.acl_cnt is correct, make sure that the length of the attributes is correct as well. Also, turn the aclp parameter into a const pointer. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: invalidate cached acl if set directly via xattrBrian Foster2015-11-031-2/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ACLs are stored as extended attributes of the inode to which they apply. XFS converts the standard "system.posix_acl_[access|default]" attribute names used to control ACLs to "trusted.SGI_ACL_[FILE|DEFAULT]" as stored on-disk. These xattrs are directly exposed in on-disk format via getxattr/setxattr, without any ACL aware code in the path to perform validation, etc. This is partly historical and supports backup/restore applications such as xfsdump to back up and restore the binary blob that represents ACLs as-is. Andreas reports that the ACLs observed via the getfacl interface is not consistent when ACLs are set directly via the setxattr path. This occurs because the ACLs are cached in-core against the inode and the xattr path has no knowledge that the operation relates to ACLs. Update the xattr set codepath to trap writes of the special XFS ACL attributes and invalidate the associated cached ACL when this occurs. This ensures that the correct ACLs are used on a subsequent operation through the actual ACL interface. Note that this does not update or add support for setting the ACL xattrs directly beyond the restore use case that requires a correctly formatted binary blob and to restore a consistent i_mode at the same time. It is still possible for a root user to set an invalid or inconsistent (with i_mode) ACL blob on-disk and potentially cause corruption. [ With fixes from Andreas Gruenbacher. ] Reported-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: clear PF_NOFREEZE for xfsaild kthreadJiri Kosina2015-11-021-0/+1
| | |/ / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since xfsaild has been converted to kthread in 0030807c, it calls try_to_freeze() during every AIL push iteration. It however doesn't set itself as freezable, and therefore this try_to_freeze() will never do anything. Before (hopefully eventually) kthread freezing gets converted to fileystem freezing, we'd rather mark xfsaild freezable (as it can generate I/O during suspend). Signed-off-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| * | | | | | | | Merge branch 'xfs-stats-fixes' into for-nextDave Chinner2015-10-193-2/+4
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| | * | | | | | | | xfs: fix an error code in xfs_fs_fill_super()Dan Carpenter2015-10-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If alloc_percpu() fails, we accidentally return PTR_ERR(NULL), which means success, but we intended to return -ENOMEM. Fixes: 225e4635580c ('xfs: per-filesystem stats in sysfs') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | xfs: stats are no longer dependent on CONFIG_PROC_FSDave Chinner2015-10-192-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So we need to fix the makefile to understand this, otherwise build errors with CONFIG_PROC_FS=n occur. Reported-and-tested-by: Jim Davis <jim.epost@gmail.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| * | | | | | | | | Merge branch 'xfs-misc-fixes-for-4.4-1' into for-nextDave Chinner2015-10-129-13/+41
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| | * | | | | | | | | xfs: more info from kmem deadlocks and high-level error msgsEric Sandeen2015-10-122-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In an effort to get more useful out of "possible memory allocation deadlock" messages, print the size of the requested allocation, and dump the stack if the xfs error level is tuned high. The stack dump is implemented in define_xfs_printk_level() for error levels >= LOGLEVEL_ERR, partly because it seems generically useful, and also because kmem.c has no knowledge of xfs error level tunables or other such bits, it's very kmem-specific. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | | xfs: avoid dependency on Linux XATTR_SIZE_MAXJan Tulak2015-10-123-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we depends on Linux XATTR value for on disk definition. Which causes trouble on other platforms and maybe also if this value was to change. Fix it by creating a custom definition independent from those in Linux (although with the same values), so it is OK with the be16 fields used for holding these attributes. This patch reflects a change in xfsprogs. Signed-off-by: Jan Tulak <jtulak@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | | xfs: prefix XATTR_LIST_MAX with XFS_Jan Tulak2015-10-123-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove a hard dependency of Linux XATTR_LIST_MAX value by using a prefixed version. This patch reflects the same change in xfsprogs. Signed-off-by: Jan Tulak <jtulak@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | | libxfs: fix two comment typosGeliang Tang2015-10-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just fix two typos in code comments. Signed-off-by: Geliang Tang <geliangtang@163.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | | xfs: Print name and pid when memory allocation loopsTetsuo Handa2015-10-122-5/+8
| | | |/ / / / / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds comm name and pid to warning messages printed by kmem_alloc(), kmem_zone_alloc() and xfs_buf_allocate_memory(). This will help telling which memory allocations (e.g. kernel worker threads, OOM victim tasks, neither) are stalling because these functions are passing __GFP_NOWARN which suppresses not only backtrace but comm name and pid. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| * | | | | | | | | Merge branch 'xfs-io-fixes' into for-nextDave Chinner2015-10-125-20/+59
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| | * | | | | | | | | xfs: add an xfs_zero_eof() tracepointBrian Foster2015-10-122-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a tracepoint in xfs_zero_eof() to facilitate tracking and debugging EOF zeroing events. This has proven useful in the context of other direct I/O tracepoints to ensure EOF zeroing occurs within appropriate file ranges. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | | xfs: always drain dio before extending aio write submissionBrian Foster2015-10-121-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | XFS supports and typically allows concurrent asynchronous direct I/O submission to a single file. One exception to the rule is that file extending dio writes that start beyond the current EOF (e.g., potentially create a hole at EOF) require exclusive I/O access to the file. This is because such writes must zero any pre-existing blocks beyond EOF that are exposed by virtue of now residing within EOF as a result of the write about to be submitted. Before EOF zeroing can occur, the current file i_size must be stabilized to avoid data corruption. In this scenario, XFS upgrades the iolock to exclude any further I/O submission, waits on in-flight I/O to complete to ensure i_size is up to date (i_size is updated on dio write completion) and restarts the various checks against the state of the file. The problem is that this protection sequence is triggered only when the iolock is currently held shared. While this is true for async dio in most cases, the caller may upgrade the lock in advance based on arbitrary circumstances with respect to EOF zeroing. For example, the iolock is always acquired exclusively if the start offset is not block aligned. This means that even though the iolock is already held exclusive for such I/Os, pending I/O is not drained and thus EOF zeroing can occur based on an unstable i_size. This problem has been reproduced as guest data corruption in virtual machines with file-backed qcow2 virtual disks hosted on an XFS filesystem. The virtual disks must be configured with aio=native mode and the must not be truncated out to the maximum file size (as some virt managers will do). Update xfs_file_aio_write_checks() to unconditionally drain in-flight dio before EOF zeroing can occur. Rather than trigger the wait based on iolock state, use a new flag and upgrade the iolock when necessary. Note that this results in a full restart of the inode checks even when the iolock was already held exclusive when technically it is only required to recheck i_size. This should be a rare enough occurrence that it is preferable to keep the code simple rather than create an alternate restart jump target. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
| | * | | | | | | | | xfs: add missing ilock around dio write last extent alignmentBrian Foster2015-10-123-12/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The iomap codepath (via get_blocks()) acquires and release the inode lock in the case of a direct write that requires block allocation. This is because xfs_iomap_write_direct() allocates a transaction, which means the ilock must be dropped and reacquired after the transaction is allocated and reserved. xfs_iomap_write_direct() invokes xfs_iomap_eof_align_last_fsb() before the transaction is created and thus before the ilock is reacquired. This can lead to calls to xfs_iread_extents() and reads of the in-core extent list without any synchronization (via xfs_bmap_eof() and xfs_bmap_last_extent()). xfs_iread_extents() assert fails if the ilock is not held, but this is not currently seen in practice as the current callers had already invoked xfs_bmapi_read(). What has been seen in practice are reports of crashes down in the xfs_bmap_eof() codepath on direct writes due to seemingly bogus pointer references from xfs_iext_get_ext(). While an explicit reproducer is not currently available to confirm the cause of the problem, crash analysis and code inspection from David Jeffrey had identified the insufficient locking. xfs_iomap_eof_align_last_fsb() is called from other contexts with the inode lock already held, so we cannot acquire it therein. __xfs_get_blocks() acquires and drops the ilock with variable flags to cover the event that the extent list must be read in. The common case is that __xfs_get_blocks() acquires the shared ilock. To provide locking around the last extent alignment call without adding more lock cycles to the dio path, update xfs_iomap_write_direct() to expect the shared ilock held on entry and do the extent alignment under its protection. Demote the lock, if necessary, from __xfs_get_blocks() and push the xfs_qm_dqattach() call outside of the shared lock critical section. Also, add an assert to document that the extent list is always expected to be present in this path. Otherwise, we risk a call to xfs_iread_extents() while under the shared ilock. This is safe as all current callers have executed an xfs_bmapi_read() call under the current iolock context. Reported-by: David Jeffery <djeffery@redhat.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>