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2019-02-03Merge tag 'for-5.0-rc4-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - regression fix: transaction commit can run away due to delayed ref waiting heuristic, this is not necessary now because of the proper reservation mechanism introduced in 5.0 - regression fix: potential crash due to use-before-check of an ERR_PTR return value - fix for transaction abort during transaction commit that needs to properly clean up pending block groups - fix deadlock during b-tree node/leaf splitting, when this happens on some of the fundamental trees, we must prevent new tree block allocation to re-enter indirectly via the block group flushing path - potential memory leak after errors during mount * tag 'for-5.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: On error always free subvol_name in btrfs_mount btrfs: clean up pending block groups when transaction commit aborts btrfs: fix potential oops in device_list_add btrfs: don't end the transaction for delayed refs in throttle Btrfs: fix deadlock when allocating tree block during leaf/node split
2019-01-30btrfs: On error always free subvol_name in btrfs_mountEric W. Biederman
The subvol_name is allocated in btrfs_parse_subvol_options and is consumed and freed in mount_subvol. Add a free to the error paths that don't call mount_subvol so that it is guaranteed that subvol_name is freed when an error happens. Fixes: 312c89fbca06 ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()") Cc: stable@vger.kernel.org # v4.19+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30btrfs: clean up pending block groups when transaction commit abortsDavid Sterba
The fstests generic/475 stresses transaction aborts and can reveal space accounting or use-after-free bugs regarding block goups. In this case the pending block groups that remain linked to the structures after transaction commit aborts in the middle. The corrupted slabs lead to failures in following tests, eg. generic/476 [ 8172.752887] BUG: unable to handle kernel NULL pointer dereference at 0000000000000058 [ 8172.755799] #PF error: [normal kernel read fault] [ 8172.757571] PGD 661ae067 P4D 661ae067 PUD 3db8e067 PMD 0 [ 8172.759000] Oops: 0000 [#1] PREEMPT SMP [ 8172.760209] CPU: 0 PID: 39 Comm: kswapd0 Tainted: G W 5.0.0-rc2-default #408 [ 8172.762495] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014 [ 8172.765772] RIP: 0010:shrink_page_list+0x2f9/0xe90 [ 8172.770453] RSP: 0018:ffff967f00663b18 EFLAGS: 00010287 [ 8172.771184] RAX: 0000000000000000 RBX: ffff967f00663c20 RCX: 0000000000000000 [ 8172.772850] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8c0620ab20e0 [ 8172.774629] RBP: ffff967f00663dd8 R08: 0000000000000000 R09: 0000000000000000 [ 8172.776094] R10: ffff8c0620ab22f8 R11: ffff8c063f772688 R12: ffff967f00663b78 [ 8172.777533] R13: ffff8c063f625600 R14: ffff8c063f625608 R15: dead000000000200 [ 8172.778886] FS: 0000000000000000(0000) GS:ffff8c063d400000(0000) knlGS:0000000000000000 [ 8172.780545] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8172.781787] CR2: 0000000000000058 CR3: 000000004e962000 CR4: 00000000000006f0 [ 8172.783547] Call Trace: [ 8172.784112] shrink_inactive_list+0x194/0x410 [ 8172.784747] shrink_node_memcg.constprop.85+0x3a5/0x6a0 [ 8172.785472] shrink_node+0x62/0x1e0 [ 8172.786011] balance_pgdat+0x216/0x460 [ 8172.786577] kswapd+0xe3/0x4a0 [ 8172.787085] ? finish_wait+0x80/0x80 [ 8172.787795] ? balance_pgdat+0x460/0x460 [ 8172.788799] kthread+0x116/0x130 [ 8172.789640] ? kthread_create_on_node+0x60/0x60 [ 8172.790323] ret_from_fork+0x24/0x30 [ 8172.794253] CR2: 0000000000000058 or accounting errors at umount time: [ 8159.537251] WARNING: CPU: 2 PID: 19031 at fs/btrfs/extent-tree.c:5987 btrfs_free_block_groups+0x3d5/0x410 [btrfs] [ 8159.543325] CPU: 2 PID: 19031 Comm: umount Tainted: G W 5.0.0-rc2-default #408 [ 8159.545472] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014 [ 8159.548155] RIP: 0010:btrfs_free_block_groups+0x3d5/0x410 [btrfs] [ 8159.554030] RSP: 0018:ffff967f079cbde8 EFLAGS: 00010206 [ 8159.555144] RAX: 0000000001000000 RBX: ffff8c06366cf800 RCX: 0000000000000000 [ 8159.556730] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff8c06255ad800 [ 8159.558279] RBP: ffff8c0637ac0000 R08: 0000000000000001 R09: 0000000000000000 [ 8159.559797] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8c0637ac0108 [ 8159.561296] R13: ffff8c0637ac0158 R14: 0000000000000000 R15: dead000000000100 [ 8159.562852] FS: 00007f7f693b9fc0(0000) GS:ffff8c063d800000(0000) knlGS:0000000000000000 [ 8159.564839] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8159.566160] CR2: 00007f7f68fab7b0 CR3: 000000000aec7000 CR4: 00000000000006e0 [ 8159.567898] Call Trace: [ 8159.568597] close_ctree+0x17f/0x350 [btrfs] [ 8159.569628] generic_shutdown_super+0x64/0x100 [ 8159.570808] kill_anon_super+0x14/0x30 [ 8159.571857] btrfs_kill_super+0x12/0xa0 [btrfs] [ 8159.573063] deactivate_locked_super+0x29/0x60 [ 8159.574234] cleanup_mnt+0x3b/0x70 [ 8159.575176] task_work_run+0x98/0xc0 [ 8159.576177] exit_to_usermode_loop+0x83/0x90 [ 8159.577315] do_syscall_64+0x15b/0x180 [ 8159.578339] entry_SYSCALL_64_after_hwframe+0x49/0xbe This fix is based on 2 Josef's patches that used sideefects of btrfs_create_pending_block_groups, this fix introduces the helper that does what we need. CC: stable@vger.kernel.org # 4.4+ CC: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30btrfs: fix potential oops in device_list_addAl Viro
alloc_fs_devices() can return ERR_PTR(-ENOMEM), so dereferencing its result before the check for IS_ERR() is a bad idea. Fixes: d1a63002829a4 ("btrfs: add members to fs_devices to track fsid changes") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-28btrfs: don't end the transaction for delayed refs in throttleJosef Bacik
Previously callers to btrfs_end_transaction_throttle() would commit the transaction if there wasn't enough delayed refs space. This happens in relocation, and if the fs is relatively empty we'll run out of delayed refs space basically immediately, so we'll just be stuck in this loop of committing the transaction over and over again. This code existed because we didn't have a good feedback mechanism for running delayed refs, but with the delayed refs rsv we do now. Delete this throttling code and let the btrfs_start_transaction() in relocation deal with putting pressure on the delayed refs infrastructure. With this patch we no longer take 5 minutes to balance a metadata only fs. Qu has submitted a fstest to catch slow balance or excessive transaction commits. Steps to reproduce: * create subvolume * create many (eg. 16000) inlined files, of size 2KiB * iteratively snapshot and touch several files to trigger metadata updates * start balance -m Reported-by: Qu Wenruo <wqu@suse.com> Fixes: 64403612b73a ("btrfs: rework btrfs_check_space_for_delayed_refs") Signed-off-by: Josef Bacik <josef@toxicpanda.com> [ add tags and steps to reproduce ] Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-28Btrfs: fix deadlock when allocating tree block during leaf/node splitFilipe Manana
When splitting a leaf or node from one of the trees that are modified when flushing pending block groups (extent, chunk, device and free space trees), we need to allocate a new tree block, which in turn can result in the need to allocate a new block group. After allocating the new block group we may need to flush new block groups that were previously allocated during the course of the current transaction, which is what may cause a deadlock due to attempts to write lock twice the same leaf or node, as when splitting a leaf or node we are holding a write lock on it and its parent node. The same type of deadlock can also happen when increasing the tree's height, since we are holding a lock on the existing root while allocating the tree block to use as the new root node. An example trace when the deadlock happens during the leaf split path is: [27175.293054] CPU: 0 PID: 3005 Comm: kworker/u17:6 Tainted: G W 4.19.16 #1 [27175.293942] Hardware name: Penguin Computing Relion 1900/MD90-FS0-ZB-XX, BIOS R15 06/25/2018 [27175.294846] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs] (...) [27175.298384] RSP: 0018:ffffab2087107758 EFLAGS: 00010246 [27175.299269] RAX: 0000000000000bbd RBX: ffff9fadc7141c48 RCX: 0000000000000001 [27175.300155] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9fadc7141c48 [27175.301023] RBP: 0000000000000001 R08: ffff9faeb6ac1040 R09: ffff9fa9c0000000 [27175.301887] R10: 0000000000000000 R11: 0000000000000040 R12: ffff9fb21aac8000 [27175.302743] R13: ffff9fb1a64d6a20 R14: 0000000000000001 R15: ffff9fb1a64d6a18 [27175.303601] FS: 0000000000000000(0000) GS:ffff9fb21fa00000(0000) knlGS:0000000000000000 [27175.304468] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27175.305339] CR2: 00007fdc8743ead8 CR3: 0000000763e0a006 CR4: 00000000003606f0 [27175.306220] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [27175.307087] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [27175.307940] Call Trace: [27175.308802] btrfs_search_slot+0x779/0x9a0 [btrfs] [27175.309669] ? update_space_info+0xba/0xe0 [btrfs] [27175.310534] btrfs_insert_empty_items+0x67/0xc0 [btrfs] [27175.311397] btrfs_insert_item+0x60/0xd0 [btrfs] [27175.312253] btrfs_create_pending_block_groups+0xee/0x210 [btrfs] [27175.313116] do_chunk_alloc+0x25f/0x300 [btrfs] [27175.313984] find_free_extent+0x706/0x10d0 [btrfs] [27175.314855] btrfs_reserve_extent+0x9b/0x1d0 [btrfs] [27175.315707] btrfs_alloc_tree_block+0x100/0x5b0 [btrfs] [27175.316548] split_leaf+0x130/0x610 [btrfs] [27175.317390] btrfs_search_slot+0x94d/0x9a0 [btrfs] [27175.318235] btrfs_insert_empty_items+0x67/0xc0 [btrfs] [27175.319087] alloc_reserved_file_extent+0x84/0x2c0 [btrfs] [27175.319938] __btrfs_run_delayed_refs+0x596/0x1150 [btrfs] [27175.320792] btrfs_run_delayed_refs+0xed/0x1b0 [btrfs] [27175.321643] delayed_ref_async_start+0x81/0x90 [btrfs] [27175.322491] normal_work_helper+0xd0/0x320 [btrfs] [27175.323328] ? move_linked_works+0x6e/0xa0 [27175.324160] process_one_work+0x191/0x370 [27175.324976] worker_thread+0x4f/0x3b0 [27175.325763] kthread+0xf8/0x130 [27175.326531] ? rescuer_thread+0x320/0x320 [27175.327284] ? kthread_create_worker_on_cpu+0x50/0x50 [27175.328027] ret_from_fork+0x35/0x40 [27175.328741] ---[ end trace 300a1b9f0ac30e26 ]--- Fix this by preventing the flushing of new blocks groups when splitting a leaf/node and when inserting a new root node for one of the trees modified by the flushing operation, similar to what is done when COWing a node/leaf from on of these trees. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202383 Reported-by: Eli V <eliventer@gmail.com> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-21Merge tag 'for-5.0-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A handful of fixes (some of them in testing for a long time): - fix some test failures regarding cleanup after transaction abort - revert of a patch that could cause a deadlock - delayed iput fixes, that can help in ENOSPC situation when there's low space and a lot data to write" * tag 'for-5.0-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: wakeup cleaner thread when adding delayed iput btrfs: run delayed iputs before committing btrfs: wait on ordered extents on abort cleanup btrfs: handle delayed ref head accounting cleanup in abort Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"
2019-01-18btrfs: wakeup cleaner thread when adding delayed iputJosef Bacik
The cleaner thread usually takes care of delayed iputs, with the exception of the btrfs_end_transaction_throttle path. Delaying iputs means we are potentially delaying the eviction of an inode and it's respective space. The cleaner thread only gets woken up every 30 seconds, or when we require space. If there are a lot of inodes that need to be deleted we could induce a serious amount of latency while we wait for these inodes to be evicted. So instead wakeup the cleaner if it's not already awake to process any new delayed iputs we add to the list. If we suddenly need space we will less likely be backed up behind a bunch of inodes that are waiting to be deleted, and we could possibly free space before we need to get into the flushing logic which will save us some latency. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18btrfs: run delayed iputs before committingJosef Bacik
Delayed iputs means we can have final iputs of deleted inodes in the queue, which could potentially generate a lot of pinned space that could be free'd. So before we decide to commit the transaction for ENOPSC reasons, run the delayed iputs so that any potential space is free'd up. If there is and we freed enough we can then commit the transaction and potentially be able to make our reservation. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18btrfs: wait on ordered extents on abort cleanupJosef Bacik
If we flip read-only before we initiate writeback on all dirty pages for ordered extents we've created then we'll have ordered extents left over on umount, which results in all sorts of bad things happening. Fix this by making sure we wait on ordered extents if we have to do the aborted transaction cleanup stuff. generic/475 can produce this warning: [ 8531.177332] WARNING: CPU: 2 PID: 11997 at fs/btrfs/disk-io.c:3856 btrfs_free_fs_root+0x95/0xa0 [btrfs] [ 8531.183282] CPU: 2 PID: 11997 Comm: umount Tainted: G W 5.0.0-rc1-default+ #394 [ 8531.185164] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014 [ 8531.187851] RIP: 0010:btrfs_free_fs_root+0x95/0xa0 [btrfs] [ 8531.193082] RSP: 0018:ffffb1ab86163d98 EFLAGS: 00010286 [ 8531.194198] RAX: ffff9f3449494d18 RBX: ffff9f34a2695000 RCX:0000000000000000 [ 8531.195629] RDX: 0000000000000002 RSI: 0000000000000001 RDI:0000000000000000 [ 8531.197315] RBP: ffff9f344e930000 R08: 0000000000000001 R09:0000000000000000 [ 8531.199095] R10: 0000000000000000 R11: ffff9f34494d4ff8 R12:ffffb1ab86163dc0 [ 8531.200870] R13: ffff9f344e9300b0 R14: ffffb1ab86163db8 R15:0000000000000000 [ 8531.202707] FS: 00007fc68e949fc0(0000) GS:ffff9f34bd800000(0000)knlGS:0000000000000000 [ 8531.204851] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8531.205942] CR2: 00007ffde8114dd8 CR3: 000000002dfbd000 CR4:00000000000006e0 [ 8531.207516] Call Trace: [ 8531.208175] btrfs_free_fs_roots+0xdb/0x170 [btrfs] [ 8531.210209] ? wait_for_completion+0x5b/0x190 [ 8531.211303] close_ctree+0x157/0x350 [btrfs] [ 8531.212412] generic_shutdown_super+0x64/0x100 [ 8531.213485] kill_anon_super+0x14/0x30 [ 8531.214430] btrfs_kill_super+0x12/0xa0 [btrfs] [ 8531.215539] deactivate_locked_super+0x29/0x60 [ 8531.216633] cleanup_mnt+0x3b/0x70 [ 8531.217497] task_work_run+0x98/0xc0 [ 8531.218397] exit_to_usermode_loop+0x83/0x90 [ 8531.219324] do_syscall_64+0x15b/0x180 [ 8531.220192] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 8531.221286] RIP: 0033:0x7fc68e5e4d07 [ 8531.225621] RSP: 002b:00007ffde8116608 EFLAGS: 00000246 ORIG_RAX:00000000000000a6 [ 8531.227512] RAX: 0000000000000000 RBX: 00005580c2175970 RCX:00007fc68e5e4d07 [ 8531.229098] RDX: 0000000000000001 RSI: 0000000000000000 RDI:00005580c2175b80 [ 8531.230730] RBP: 0000000000000000 R08: 00005580c2175ba0 R09:00007ffde8114e80 [ 8531.232269] R10: 0000000000000000 R11: 0000000000000246 R12:00005580c2175b80 [ 8531.233839] R13: 00007fc68eac61c4 R14: 00005580c2175a68 R15:0000000000000000 Leaving a tree in the rb-tree: 3853 void btrfs_free_fs_root(struct btrfs_root *root) 3854 { 3855 iput(root->ino_cache_inode); 3856 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); CC: stable@vger.kernel.org Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> [ add stacktrace ] Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18btrfs: handle delayed ref head accounting cleanup in abortJosef Bacik
We weren't doing any of the accounting cleanup when we aborted transactions. Fix this by making cleanup_ref_head_accounting global and calling it from the abort code, this fixes the issue where our accounting was all wrong after the fs aborts. The test generic/475 on a 2G VM can trigger the problems eg.: [ 8502.136957] WARNING: CPU: 0 PID: 11064 at fs/btrfs/extent-tree.c:5986 btrfs_free_block_grou +ps+0x3dc/0x410 [btrfs] [ 8502.148372] CPU: 0 PID: 11064 Comm: umount Not tainted 5.0.0-rc1-default+ #394 [ 8502.150807] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626 +cc-prebuilt.qemu-project.org 04/01/2014 [ 8502.154317] RIP: 0010:btrfs_free_block_groups+0x3dc/0x410 [btrfs] [ 8502.160623] RSP: 0018:ffffb1ab84b93de8 EFLAGS: 00010206 [ 8502.161906] RAX: 0000000001000000 RBX: ffff9f34b1756400 RCX: 0000000000000000 [ 8502.163448] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff9f34b1755400 [ 8502.164906] RBP: ffff9f34b7e8c000 R08: 0000000000000001 R09: 0000000000000000 [ 8502.166716] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9f34b7e8c108 [ 8502.168498] R13: ffff9f34b7e8c158 R14: 0000000000000000 R15: dead000000000100 [ 8502.170296] FS: 00007fb1cf15ffc0(0000) GS:ffff9f34bd400000(0000) knlGS:0000000000000000 [ 8502.172439] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8502.173669] CR2: 00007fb1ced507b0 CR3: 000000002f7a6000 CR4: 00000000000006f0 [ 8502.175094] Call Trace: [ 8502.175759] close_ctree+0x17f/0x350 [btrfs] [ 8502.176721] generic_shutdown_super+0x64/0x100 [ 8502.177702] kill_anon_super+0x14/0x30 [ 8502.178607] btrfs_kill_super+0x12/0xa0 [btrfs] [ 8502.179602] deactivate_locked_super+0x29/0x60 [ 8502.180595] cleanup_mnt+0x3b/0x70 [ 8502.181406] task_work_run+0x98/0xc0 [ 8502.182255] exit_to_usermode_loop+0x83/0x90 [ 8502.183113] do_syscall_64+0x15b/0x180 [ 8502.183919] entry_SYSCALL_64_after_hwframe+0x49/0xbe Corresponding to release_global_block_rsv() { ... WARN_ON(fs_info->delayed_refs_rsv.reserved > 0); CC: stable@vger.kernel.org Signed-off-by: Josef Bacik <josef@toxicpanda.com> [ add log dump ] Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"David Sterba
This reverts commit e73e81b6d0114d4a303205a952ab2e87c44bd279. This patch causes a few problems: - adds latency to btrfs_finish_ordered_io - as btrfs_finish_ordered_io is used for free space cache, generating more work from btrfs_btree_balance_dirty_nodelay could end up in the same workque, effectively deadlocking 12260 kworker/u96:16+btrfs-freespace-write D [<0>] balance_dirty_pages+0x6e6/0x7ad [<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90 [<0>] btrfs_finish_ordered_io+0x3da/0x770 [<0>] normal_work_helper+0x1c5/0x5a0 [<0>] process_one_work+0x1ee/0x5a0 [<0>] worker_thread+0x46/0x3d0 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff Transaction commit will wait on the freespace cache: 838 btrfs-transacti D [<0>] btrfs_start_ordered_extent+0x154/0x1e0 [<0>] btrfs_wait_ordered_range+0xbd/0x110 [<0>] __btrfs_wait_cache_io+0x49/0x1a0 [<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0 [<0>] commit_cowonly_roots+0x215/0x2b0 [<0>] btrfs_commit_transaction+0x37e/0x910 [<0>] transaction_kthread+0x14d/0x180 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff And then writepages ends up waiting on transaction commit: 9520 kworker/u96:13+flush-btrfs-1 D [<0>] wait_current_trans+0xac/0xe0 [<0>] start_transaction+0x21b/0x4b0 [<0>] cow_file_range_inline+0x10b/0x6b0 [<0>] cow_file_range.isra.69+0x329/0x4a0 [<0>] run_delalloc_range+0x105/0x3c0 [<0>] writepage_delalloc+0x119/0x180 [<0>] __extent_writepage+0x10c/0x390 [<0>] extent_write_cache_pages+0x26f/0x3d0 [<0>] extent_writepages+0x4f/0x80 [<0>] do_writepages+0x17/0x60 [<0>] __writeback_single_inode+0x59/0x690 [<0>] writeback_sb_inodes+0x291/0x4e0 [<0>] __writeback_inodes_wb+0x87/0xb0 [<0>] wb_writeback+0x3bb/0x500 [<0>] wb_workfn+0x40d/0x610 [<0>] process_one_work+0x1ee/0x5a0 [<0>] worker_thread+0x1e0/0x3d0 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff Eventually, we have every process in the system waiting on balance_dirty_pages(), and nobody is able to make progress on page writeback. The original patch tried to fix an OOM condition, that happened on 4.4 but no success reproducing that on later kernels (4.19 and 4.20). This is more likely a problem in OOM itself. Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/ Reported-by: Chris Mason <clm@fb.com> CC: stable@vger.kernel.org # 4.18+ CC: ethanlien <ethanlien@synology.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-14Merge tag 'for-5.0-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - two regression fixes in clone/dedupe ioctls, the generic check callback needs to lock extents properly and wait for io to avoid problems with writeback and relocation - fix deadlock when using free space tree due to block group creation - a recently added check refuses a valid fileystem with seeding device, make that work again with a quickfix, proper solution needs more intrusive changes * tag 'for-5.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Use real device structure to verify dev extent Btrfs: fix deadlock when using free space tree due to block group creation Btrfs: fix race between reflink/dedupe and relocation Btrfs: fix race between cloning range ending at eof and writeback
2019-01-10btrfs: Use real device structure to verify dev extentQu Wenruo
[BUG] Linux v5.0-rc1 will fail fstests/btrfs/163 with the following kernel message: BTRFS error (device dm-6): dev extent devid 1 physical offset 13631488 len 8388608 is beyond device boundary 0 BTRFS error (device dm-6): failed to verify dev extents against chunks: -117 BTRFS error (device dm-6): open_ctree failed [CAUSE] Commit cf90d884b347 ("btrfs: Introduce mount time chunk <-> dev extent mapping check") introduced strict check on dev extents. We use btrfs_find_device() with dev uuid and fs uuid set to NULL, and only dependent on @devid to find the real device. For seed devices, we call clone_fs_devices() in open_seed_devices() to allow us search seed devices directly. However clone_fs_devices() just populates devices with devid and dev uuid, without populating other essential members, like disk_total_bytes. This makes any device returned by btrfs_find_device(fs_info, devid, NULL, NULL) is just a dummy, with 0 disk_total_bytes, and any dev extents on the seed device will not pass the device boundary check. [FIX] This patch will try to verify the device returned by btrfs_find_device() and if it's a dummy then re-search in seed devices. Fixes: cf90d884b347 ("btrfs: Introduce mount time chunk <-> dev extent mapping check") CC: stable@vger.kernel.org # 4.19+ Reported-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-09Btrfs: fix deadlock when using free space tree due to block group creationFilipe Manana
When modifying the free space tree we can end up COWing one of its extent buffers which in turn might result in allocating a new chunk, which in turn can result in flushing (finish creation) of pending block groups. If that happens we can deadlock because creating a pending block group needs to update the free space tree, and if any of the updates tries to modify the same extent buffer that we are COWing, we end up in a deadlock since we try to write lock twice the same extent buffer. So fix this by skipping pending block group creation if we are COWing an extent buffer from the free space tree. This is a case missed by commit 5ce555578e091 ("Btrfs: fix deadlock when writing out free space caches"). Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202173 Fixes: 5ce555578e091 ("Btrfs: fix deadlock when writing out free space caches") CC: stable@vger.kernel.org # 4.18+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-09Btrfs: fix race between reflink/dedupe and relocationFilipe Manana
The recent rework that makes btrfs' remap_file_range operation use the generic helper generic_remap_file_range_prep() introduced a race between relocation and reflinking (for both cloning and deduplication) the file extents between the source and destination inodes. This happens because we no longer lock the source range anymore, and we do not lock it anymore because we wait for direct IO writes and writeback to complete early on the code path right after locking the inodes, which guarantees no other file operations interfere with the reflinking. However there is one exception which is relocation, since it replaces the byte number of file extents items in the fs tree after locking the range the file extent items represent. This is a problem because after finding each file extent to clone in the fs tree, the reflink process copies the file extent item into a local buffer, releases the search path, inserts new file extent items in the destination range and then increments the reference count for the extent mentioned in the file extent item that it previously copied to the buffer. If right after copying the file extent item into the buffer and releasing the path the relocation process updates the file extent item to point to the new extent, the reflink process ends up creating a delayed reference to increment the reference count of the old extent, for which the relocation process already created a delayed reference to drop it. This results in failure to run delayed references because we will attempt to increment the count of a reference that was already dropped. This is illustrated by the following diagram: CPU 1 CPU 2 relocation is running btrfs_clone_files() btrfs_clone() --> finds extent item in source range point to extent at bytenr X --> copies it into a local buffer --> releases path replace_file_extents() --> successfully locks the range represented by the file extent item --> replaces disk_bytenr field in the file extent item with some other value Y --> creates delayed reference to increment reference count for extent at bytenr Y --> creates delayed reference to drop the extent at bytenr X --> starts transaction --> creates delayed reference to increment extent at bytenr X <delayed references are run, due to a transaction commit for example, and the transaction is aborted with -EIO because we attempt to increment reference count for the extent at bytenr X after we freed it> When this race is hit the running transaction ends up getting aborted with an -EIO error and a trace like the following is produced: [ 4382.553858] WARNING: CPU: 2 PID: 3648 at fs/btrfs/extent-tree.c:1552 lookup_inline_extent_backref+0x4f4/0x650 [btrfs] (...) [ 4382.556293] CPU: 2 PID: 3648 Comm: btrfs Tainted: G W 4.20.0-rc6-btrfs-next-41 #1 [ 4382.556294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [ 4382.556308] RIP: 0010:lookup_inline_extent_backref+0x4f4/0x650 [btrfs] (...) [ 4382.556310] RSP: 0018:ffffac784408f738 EFLAGS: 00010202 [ 4382.556311] RAX: 0000000000000001 RBX: ffff8980673c3a48 RCX: 0000000000000001 [ 4382.556312] RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000000 [ 4382.556312] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 4382.556313] R10: 0000000000000001 R11: ffff897f40000000 R12: 0000000000001000 [ 4382.556313] R13: 00000000c224f000 R14: ffff89805de9bd40 R15: ffff8980453f4548 [ 4382.556315] FS: 00007f5e759178c0(0000) GS:ffff89807b300000(0000) knlGS:0000000000000000 [ 4382.563130] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4382.563562] CR2: 00007f2e9789fcbc CR3: 0000000120512001 CR4: 00000000003606e0 [ 4382.564005] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 4382.564451] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 4382.564887] Call Trace: [ 4382.565343] insert_inline_extent_backref+0x55/0xe0 [btrfs] [ 4382.565796] __btrfs_inc_extent_ref.isra.60+0x88/0x260 [btrfs] [ 4382.566249] ? __btrfs_run_delayed_refs+0x93/0x1650 [btrfs] [ 4382.566702] __btrfs_run_delayed_refs+0xa22/0x1650 [btrfs] [ 4382.567162] btrfs_run_delayed_refs+0x7e/0x1d0 [btrfs] [ 4382.567623] btrfs_commit_transaction+0x50/0x9c0 [btrfs] [ 4382.568112] ? _raw_spin_unlock+0x24/0x30 [ 4382.568557] ? block_rsv_release_bytes+0x14e/0x410 [btrfs] [ 4382.569006] create_subvol+0x3c8/0x830 [btrfs] [ 4382.569461] ? btrfs_mksubvol+0x317/0x600 [btrfs] [ 4382.569906] btrfs_mksubvol+0x317/0x600 [btrfs] [ 4382.570383] ? rcu_sync_lockdep_assert+0xe/0x60 [ 4382.570822] ? __sb_start_write+0xd4/0x1c0 [ 4382.571262] ? mnt_want_write_file+0x24/0x50 [ 4382.571712] btrfs_ioctl_snap_create_transid+0x117/0x1a0 [btrfs] [ 4382.572155] ? _copy_from_user+0x66/0x90 [ 4382.572602] btrfs_ioctl_snap_create+0x66/0x80 [btrfs] [ 4382.573052] btrfs_ioctl+0x7c1/0x30e0 [btrfs] [ 4382.573502] ? mem_cgroup_commit_charge+0x8b/0x570 [ 4382.573946] ? do_raw_spin_unlock+0x49/0xc0 [ 4382.574379] ? _raw_spin_unlock+0x24/0x30 [ 4382.574803] ? __handle_mm_fault+0xf29/0x12d0 [ 4382.575215] ? do_vfs_ioctl+0xa2/0x6f0 [ 4382.575622] ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs] [ 4382.576020] do_vfs_ioctl+0xa2/0x6f0 [ 4382.576405] ksys_ioctl+0x70/0x80 [ 4382.576776] __x64_sys_ioctl+0x16/0x20 [ 4382.577137] do_syscall_64+0x60/0x1b0 [ 4382.577488] entry_SYSCALL_64_after_hwframe+0x49/0xbe (...) [ 4382.578837] RSP: 002b:00007ffe04bf64c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 4382.579174] RAX: ffffffffffffffda RBX: 00005564136f3050 RCX: 00007f5e74724dd7 [ 4382.579505] RDX: 00007ffe04bf64d0 RSI: 000000005000940e RDI: 0000000000000003 [ 4382.579848] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000044 [ 4382.580164] R10: 0000000000000541 R11: 0000000000000202 R12: 00005564136f3010 [ 4382.580477] R13: 0000000000000003 R14: 00005564136f3035 R15: 00005564136f3050 [ 4382.580792] irq event stamp: 0 [ 4382.581106] hardirqs last enabled at (0): [<0000000000000000>] (null) [ 4382.581441] hardirqs last disabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320 [ 4382.581772] softirqs last enabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320 [ 4382.582095] softirqs last disabled at (0): [<0000000000000000>] (null) [ 4382.582413] ---[ end trace d3c188e3e9367382 ]--- [ 4382.623855] BTRFS: error (device sdc) in btrfs_run_delayed_refs:2981: errno=-5 IO failure [ 4382.624295] BTRFS info (device sdc): forced readonly Fix this by locking the source range before searching for the file extent items in the fs tree, since the relocation process will try to lock the range a file extent item represents before updating it with the new extent location. Fixes: 34a28e3d7753 ("Btrfs: use generic_remap_file_range_prep() for cloning and deduplication") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-09Btrfs: fix race between cloning range ending at eof and writebackFilipe Manana
The recent rework that makes btrfs' remap_file_range operation use the generic helper generic_remap_file_range_prep() introduced a race between writeback and cloning a range that covers the eof extent of the source file into a destination offset that is greater then the same file's size. This happens because we now wait for writeback to complete before doing the truncation of the eof block, while previously we did the truncation and then waited for writeback to complete. This leads to a race between writeback of the truncated block and cloning the file extents in the source range, because we copy each file extent item we find in the fs root into a buffer, then release the path and then increment the reference count for the extent referred in that file extent item we copied, which can no longer exist if writeback of the truncated eof block completes after we copied the file extent item into the buffer and before we incremented the reference count. This is illustrated by the following diagram: CPU 1 CPU 2 btrfs_clone_files() btrfs_cont_expand() btrfs_truncate_block() --> zeroes part of the page containg eof, marking it for delalloc btrfs_clone() --> finds extent item covering eof, points to extent at bytenr X --> copies it into a local buffer --> releases path writeback starts btrfs_finish_ordered_io() insert_reserved_file_extent() __btrfs_drop_extents() --> creates delayed reference to drop the extent at bytenr X --> starts transaction --> creates delayed reference to increment extent at bytenr X <delayed references are run, due to a transaction commit for example, and the transaction is aborted with -EIO because we attempt to increment reference count for the extent at bytenr X after we freed it> When this race is hit the running transaction ends up getting aborted with an -EIO error and a trace like the following is produced: [ 4382.553858] WARNING: CPU: 2 PID: 3648 at fs/btrfs/extent-tree.c:1552 lookup_inline_extent_backref+0x4f4/0x650 [btrfs] (...) [ 4382.556293] CPU: 2 PID: 3648 Comm: btrfs Tainted: G W 4.20.0-rc6-btrfs-next-41 #1 [ 4382.556294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [ 4382.556308] RIP: 0010:lookup_inline_extent_backref+0x4f4/0x650 [btrfs] (...) [ 4382.556310] RSP: 0018:ffffac784408f738 EFLAGS: 00010202 [ 4382.556311] RAX: 0000000000000001 RBX: ffff8980673c3a48 RCX: 0000000000000001 [ 4382.556312] RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000000 [ 4382.556312] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 4382.556313] R10: 0000000000000001 R11: ffff897f40000000 R12: 0000000000001000 [ 4382.556313] R13: 00000000c224f000 R14: ffff89805de9bd40 R15: ffff8980453f4548 [ 4382.556315] FS: 00007f5e759178c0(0000) GS:ffff89807b300000(0000) knlGS:0000000000000000 [ 4382.563130] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4382.563562] CR2: 00007f2e9789fcbc CR3: 0000000120512001 CR4: 00000000003606e0 [ 4382.564005] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 4382.564451] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 4382.564887] Call Trace: [ 4382.565343] insert_inline_extent_backref+0x55/0xe0 [btrfs] [ 4382.565796] __btrfs_inc_extent_ref.isra.60+0x88/0x260 [btrfs] [ 4382.566249] ? __btrfs_run_delayed_refs+0x93/0x1650 [btrfs] [ 4382.566702] __btrfs_run_delayed_refs+0xa22/0x1650 [btrfs] [ 4382.567162] btrfs_run_delayed_refs+0x7e/0x1d0 [btrfs] [ 4382.567623] btrfs_commit_transaction+0x50/0x9c0 [btrfs] [ 4382.568112] ? _raw_spin_unlock+0x24/0x30 [ 4382.568557] ? block_rsv_release_bytes+0x14e/0x410 [btrfs] [ 4382.569006] create_subvol+0x3c8/0x830 [btrfs] [ 4382.569461] ? btrfs_mksubvol+0x317/0x600 [btrfs] [ 4382.569906] btrfs_mksubvol+0x317/0x600 [btrfs] [ 4382.570383] ? rcu_sync_lockdep_assert+0xe/0x60 [ 4382.570822] ? __sb_start_write+0xd4/0x1c0 [ 4382.571262] ? mnt_want_write_file+0x24/0x50 [ 4382.571712] btrfs_ioctl_snap_create_transid+0x117/0x1a0 [btrfs] [ 4382.572155] ? _copy_from_user+0x66/0x90 [ 4382.572602] btrfs_ioctl_snap_create+0x66/0x80 [btrfs] [ 4382.573052] btrfs_ioctl+0x7c1/0x30e0 [btrfs] [ 4382.573502] ? mem_cgroup_commit_charge+0x8b/0x570 [ 4382.573946] ? do_raw_spin_unlock+0x49/0xc0 [ 4382.574379] ? _raw_spin_unlock+0x24/0x30 [ 4382.574803] ? __handle_mm_fault+0xf29/0x12d0 [ 4382.575215] ? do_vfs_ioctl+0xa2/0x6f0 [ 4382.575622] ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs] [ 4382.576020] do_vfs_ioctl+0xa2/0x6f0 [ 4382.576405] ksys_ioctl+0x70/0x80 [ 4382.576776] __x64_sys_ioctl+0x16/0x20 [ 4382.577137] do_syscall_64+0x60/0x1b0 [ 4382.577488] entry_SYSCALL_64_after_hwframe+0x49/0xbe (...) [ 4382.578837] RSP: 002b:00007ffe04bf64c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 4382.579174] RAX: ffffffffffffffda RBX: 00005564136f3050 RCX: 00007f5e74724dd7 [ 4382.579505] RDX: 00007ffe04bf64d0 RSI: 000000005000940e RDI: 0000000000000003 [ 4382.579848] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000044 [ 4382.580164] R10: 0000000000000541 R11: 0000000000000202 R12: 00005564136f3010 [ 4382.580477] R13: 0000000000000003 R14: 00005564136f3035 R15: 00005564136f3050 [ 4382.580792] irq event stamp: 0 [ 4382.581106] hardirqs last enabled at (0): [<0000000000000000>] (null) [ 4382.581441] hardirqs last disabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320 [ 4382.581772] softirqs last enabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320 [ 4382.582095] softirqs last disabled at (0): [<0000000000000000>] (null) [ 4382.582413] ---[ end trace d3c188e3e9367382 ]--- [ 4382.623855] BTRFS: error (device sdc) in btrfs_run_delayed_refs:2981: errno=-5 IO failure [ 4382.624295] BTRFS info (device sdc): forced readonly Fix this by waiting for writeback to complete after truncating the eof block. Fixes: 34a28e3d7753 ("Btrfs: use generic_remap_file_range_prep() for cloning and deduplication") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-05Merge branch 'mount.part1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount API prep from Al Viro: "Mount API prereqs. Mostly that's LSM mount options cleanups. There are several minor fixes in there, but nothing earth-shattering (leaks on failure exits, mostly)" * 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits) mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT smack: rewrite smack_sb_eat_lsm_opts() smack: get rid of match_token() smack: take the guts of smack_parse_opts_str() into a new helper LSM: new method: ->sb_add_mnt_opt() selinux: rewrite selinux_sb_eat_lsm_opts() selinux: regularize Opt_... names a bit selinux: switch away from match_token() selinux: new helper - selinux_add_opt() LSM: bury struct security_mnt_opts smack: switch to private smack_mnt_opts selinux: switch to private struct selinux_mnt_opts LSM: hide struct security_mnt_opts from any generic code selinux: kill selinux_sb_get_mnt_opts() LSM: turn sb_eat_lsm_opts() into a method nfs_remount(): don't leak, don't ignore LSM options quietly btrfs: sanitize security_mnt_opts use selinux; don't open-code a loop in sb_finish_set_opts() LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount() new helper: security_sb_eat_lsm_opts() ...
2019-01-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - procfs updates - various misc bits - lib/ updates - epoll updates - autofs - fatfs - a few more MM bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits) mm/page_io.c: fix polled swap page in checkpatch: add Co-developed-by to signature tags docs: fix Co-Developed-by docs drivers/base/platform.c: kmemleak ignore a known leak fs: don't open code lru_to_page() fs/: remove caller signal_pending branch predictions mm/: remove caller signal_pending branch predictions arch/arc/mm/fault.c: remove caller signal_pending_branch predictions kernel/sched/: remove caller signal_pending branch predictions kernel/locking/mutex.c: remove caller signal_pending branch predictions mm: select HAVE_MOVE_PMD on x86 for faster mremap mm: speed up mremap by 20x on large regions mm: treewide: remove unused address argument from pte_alloc functions initramfs: cleanup incomplete rootfs scripts/gdb: fix lx-version string output kernel/kcov.c: mark write_comp_data() as notrace kernel/sysctl: add panic_print into sysctl panic: add options to print system info when panic happens bfs: extra sanity checking and static inode bitmap exec: separate MM_ANONPAGES and RLIMIT_STACK accounting ...
2019-01-04fs: don't open code lru_to_page()Nikolay Borisov
Multiple filesystems open code lru_to_page(). Rectify this by moving the macro from mm_inline (which is specific to lru stuff) to the more generic mm.h header and start using the macro where appropriate. No functional changes. Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com Signed-off-by: Nikolay Borisov <nborisov@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Pankaj gupta <pagupta@redhat.com> Acked-by: "Yan, Zheng" <zyan@redhat.com> [ceph] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-21LSM: hide struct security_mnt_opts from any generic codeAl Viro
Keep void * instead, allocate on demand (in parse_str_opts, at the moment). Eventually both selinux and smack will be better off with private structures with several strings in those, rather than this "counter and two pointers to dynamically allocated arrays" ugliness. This commit allows to do that at leisure, without disrupting anything outside of given module. Changes: * instead of struct security_mnt_opt use an opaque pointer initialized to NULL. * security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and security_free_mnt_opts() take it as var argument (i.e. as void **); call sites are unchanged. * security_sb_set_mnt_opts() and security_sb_remount() take it by value (i.e. as void *). * new method: ->sb_free_mnt_opts(). Takes void *, does whatever freeing that needs to be done. * ->sb_set_mnt_opts() and ->sb_remount() might get NULL as mnt_opts argument, meaning "empty". Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21btrfs: sanitize security_mnt_opts useAl Viro
1) keeping a copy in btrfs_fs_info is completely pointless - we never use it for anything. Getting rid of that allows for simpler calling conventions for setup_security_options() (caller is responsible for freeing mnt_opts in all cases). 2) on remount we want to use ->sb_remount(), not ->sb_set_mnt_opts(), same as we would if not for FS_BINARY_MOUNTDATA. Behaviours *are* close (in fact, selinux sb_set_mnt_opts() ought to punt to sb_remount() in "already initialized" case), but let's handle that uniformly. And the only reason why the original btrfs changes didn't go for security_sb_remount() in btrfs_remount() case is that it hadn't been exported. Let's export it for a while - it'll be going away soon anyway. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21new helper: security_sb_eat_lsm_opts()Al Viro
combination of alloc_secdata(), security_sb_copy_data(), security_sb_parse_opt_str() and free_secdata(). Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-17btrfs: Fix typos in comments and stringsAndrea Gelmini
The typos accumulate over time so once in a while time they get fixed in a large patch. Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: improve error handling of btrfs_add_linkJohannes Thumshirn
In the error handling block, err holds the return value of either btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked since it's introduction with commit fe66a05a0679 (Btrfs: improve error handling for btrfs_insert_dir_item callers) in 2012. If the error handling in the error handling fails, there's not much left to do and the abort either happened earlier in the callees or is necessary here. So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort the transaction, but still return the original code of the failure stored in 'ret' as this will be reported to the user. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17Btrfs: use generic_remap_file_range_prep() for cloning and deduplicationFilipe Manana
Since cloning and deduplication are no longer Btrfs specific operations, we now have generic code to handle parameter validation, compare file ranges used for deduplication, clear capabilities when cloning, etc. This change makes Btrfs use it, eliminating a lot of code in Btrfs and also fixing a few bugs, such as: 1) When cloning, the destination file's capabilities were not dropped (the fstest generic/513 tests this); 2) We were not checking if the destination file is immutable; 3) Not checking if either the source or destination files are swap files (swap file support is coming soon for Btrfs); 4) System limits were not checked (resource limits and O_LARGEFILE). Note that the generic helper generic_remap_file_range_prep() does start and waits for writeback by calling filemap_write_and_wait_range(), however that is not enough for Btrfs for two reasons: 1) With compression, we need to start writeback twice in order to get the pages marked for writeback and ordered extents created; 2) filemap_write_and_wait_range() (and all its other variants) only waits for the IO to complete, but we need to wait for the ordered extents to finish, so that when we do the actual reflinking operations the file extent items are in the fs tree. This is also important due to the fact that the generic helper, for the deduplication case, compares the contents of the pages in the requested range, which might require reading extents from disk in the very unlikely case that pages get invalidated after writeback finishes (so the file extent items must be up to date in the fs tree). Since these reasons are specific to Btrfs we have to do it in the Btrfs code before calling generic_remap_file_range_prep(). This also results in a simpler way of dealing with existing delalloc in the source/target ranges, specially for the deduplication case where we used to lock all the pages first and then if we found any dealloc for the range, or ordered extent, we would unlock the pages trigger writeback and wait for ordered extents to complete, then lock all the pages again and check if deduplication can be done. So now we get a simpler approach: lock the inodes, then trigger writeback and then wait for ordered extents to complete. So make btrfs use generic_remap_file_range_prep() (XFS and OCFS2 use it) to eliminate duplicated code, fix a few bugs and benefit from future bug fixes done there - for example the recent clone and dedupe bugs involving reflinking a partial EOF block got a counterpart fix in the generic helper, since it affected all filesystems supporting these operations, so we no longer need special checks in Btrfs for them. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Refactor main loop in extent_readpagesNikolay Borisov
extent_readpages processes all pages in the readlist in batches of 16, this is implemented by a single for loop but thanks to an if condition the loop does 2 things based on whether we've filled the batch or not. Additionally due to the structure of the code there is an additional check which deals with partial batches. Streamline all of this by explicitly using two loops. The outter one is used to process all pages while the inner one just fills in the batch of 16 (currently). Due to this new structure the code guarantees that all pages are processed in the loop hence the code to deal with any leftovers is eliminated. This also enable the compiler to inline __extent_readpages: ./scripts/bloat-o-meter fs/btrfs/extent_io.o extent_io.for add/remove: 0/1 grow/shrink: 1/0 up/down: 660/-820 (-160) Function old new delta extent_readpages 476 1136 +660 __extent_readpages 820 - -820 Total: Before=44315, After=44155, chg -0.36% Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Re