- 25 8月, 2019 1 次提交
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由 Filipe Manana 提交于
[ Upstream commit a6d155d2e363f26290ffd50591169cb96c2a609e ] The fiemap handler locks a file range that can have unflushed delalloc, and after locking the range, it tries to attach to a running transaction. If the running transaction started its commit, that is, it is in state TRANS_STATE_COMMIT_START, and either the filesystem was mounted with the flushoncommit option or the transaction is creating a snapshot for the subvolume that contains the file that fiemap is operating on, we end up deadlocking. This happens because fiemap is blocked on the transaction, waiting for it to complete, and the transaction is waiting for the flushed dealloc to complete, which requires locking the file range that the fiemap task already locked. The following stack traces serve as an example of when this deadlock happens: (...) [404571.515510] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [404571.515956] Call Trace: [404571.516360] ? __schedule+0x3ae/0x7b0 [404571.516730] schedule+0x3a/0xb0 [404571.517104] lock_extent_bits+0x1ec/0x2a0 [btrfs] [404571.517465] ? remove_wait_queue+0x60/0x60 [404571.517832] btrfs_finish_ordered_io+0x292/0x800 [btrfs] [404571.518202] normal_work_helper+0xea/0x530 [btrfs] [404571.518566] process_one_work+0x21e/0x5c0 [404571.518990] worker_thread+0x4f/0x3b0 [404571.519413] ? process_one_work+0x5c0/0x5c0 [404571.519829] kthread+0x103/0x140 [404571.520191] ? kthread_create_worker_on_cpu+0x70/0x70 [404571.520565] ret_from_fork+0x3a/0x50 [404571.520915] kworker/u8:6 D 0 31651 2 0x80004000 [404571.521290] Workqueue: btrfs-flush_delalloc btrfs_flush_delalloc_helper [btrfs] (...) [404571.537000] fsstress D 0 13117 13115 0x00004000 [404571.537263] Call Trace: [404571.537524] ? __schedule+0x3ae/0x7b0 [404571.537788] schedule+0x3a/0xb0 [404571.538066] wait_current_trans+0xc8/0x100 [btrfs] [404571.538349] ? remove_wait_queue+0x60/0x60 [404571.538680] start_transaction+0x33c/0x500 [btrfs] [404571.539076] btrfs_check_shared+0xa3/0x1f0 [btrfs] [404571.539513] ? extent_fiemap+0x2ce/0x650 [btrfs] [404571.539866] extent_fiemap+0x2ce/0x650 [btrfs] [404571.540170] do_vfs_ioctl+0x526/0x6f0 [404571.540436] ksys_ioctl+0x70/0x80 [404571.540734] __x64_sys_ioctl+0x16/0x20 [404571.540997] do_syscall_64+0x60/0x1d0 [404571.541279] entry_SYSCALL_64_after_hwframe+0x49/0xbe (...) [404571.543729] btrfs D 0 14210 14208 0x00004000 [404571.544023] Call Trace: [404571.544275] ? __schedule+0x3ae/0x7b0 [404571.544526] ? wait_for_completion+0x112/0x1a0 [404571.544795] schedule+0x3a/0xb0 [404571.545064] schedule_timeout+0x1ff/0x390 [404571.545351] ? lock_acquire+0xa6/0x190 [404571.545638] ? wait_for_completion+0x49/0x1a0 [404571.545890] ? wait_for_completion+0x112/0x1a0 [404571.546228] wait_for_completion+0x131/0x1a0 [404571.546503] ? wake_up_q+0x70/0x70 [404571.546775] btrfs_wait_ordered_extents+0x27c/0x400 [btrfs] [404571.547159] btrfs_commit_transaction+0x3b0/0xae0 [btrfs] [404571.547449] ? btrfs_mksubvol+0x4a4/0x640 [btrfs] [404571.547703] ? remove_wait_queue+0x60/0x60 [404571.547969] btrfs_mksubvol+0x605/0x640 [btrfs] [404571.548226] ? __sb_start_write+0xd4/0x1c0 [404571.548512] ? mnt_want_write_file+0x24/0x50 [404571.548789] btrfs_ioctl_snap_create_transid+0x169/0x1a0 [btrfs] [404571.549048] btrfs_ioctl_snap_create_v2+0x11d/0x170 [btrfs] [404571.549307] btrfs_ioctl+0x133f/0x3150 [btrfs] [404571.549549] ? mem_cgroup_charge_statistics+0x4c/0xd0 [404571.549792] ? mem_cgroup_commit_charge+0x84/0x4b0 [404571.550064] ? __handle_mm_fault+0xe3e/0x11f0 [404571.550306] ? do_raw_spin_unlock+0x49/0xc0 [404571.550608] ? _raw_spin_unlock+0x24/0x30 [404571.550976] ? __handle_mm_fault+0xedf/0x11f0 [404571.551319] ? do_vfs_ioctl+0xa2/0x6f0 [404571.551659] ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs] [404571.552087] do_vfs_ioctl+0xa2/0x6f0 [404571.552355] ksys_ioctl+0x70/0x80 [404571.552621] __x64_sys_ioctl+0x16/0x20 [404571.552864] do_syscall_64+0x60/0x1d0 [404571.553104] entry_SYSCALL_64_after_hwframe+0x49/0xbe (...) If we were joining the transaction instead of attaching to it, we would not risk a deadlock because a join only blocks if the transaction is in a state greater then or equals to TRANS_STATE_COMMIT_DOING, and the delalloc flush performed by a transaction is done before it reaches that state, when it is in the state TRANS_STATE_COMMIT_START. However a transaction join is intended for use cases where we do modify the filesystem, and fiemap only needs to peek at delayed references from the current transaction in order to determine if extents are shared, and, besides that, when there is no current transaction or when it blocks to wait for a current committing transaction to complete, it creates a new transaction without reserving any space. Such unnecessary transactions, besides doing unnecessary IO, can cause transaction aborts (-ENOSPC) and unnecessary rotation of the precious backup roots. So fix this by adding a new transaction join variant, named join_nostart, which behaves like the regular join, but it does not create a transaction when none currently exists or after waiting for a committing transaction to complete. Fixes: 03628cdbc64db6 ("Btrfs: do not start a transaction during fiemap") Signed-off-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 31 5月, 2019 1 次提交
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由 Josef Bacik 提交于
commit 38e3eebff643db725633657d1d87a3be019d1018 upstream. Qgroups will do the old roots lookup at delayed ref time, which could be while walking down the extent root while running a delayed ref. This should be fine, except we specifically lock eb's in the backref walking code irrespective of path->skip_locking, which deadlocks the system. Fix up the backref code to honor path->skip_locking, nobody will be modifying the commit_root when we're searching so it's completely safe to do. This happens since fb235dc0 ("btrfs: qgroup: Move half of the qgroup accounting time out of commit trans"), kernel may lockup with quota enabled. There is one backref trace triggered by snapshot dropping along with write operation in the source subvolume. The example can be reliably reproduced: btrfs-cleaner D 0 4062 2 0x80000000 Call Trace: schedule+0x32/0x90 btrfs_tree_read_lock+0x93/0x130 [btrfs] find_parent_nodes+0x29b/0x1170 [btrfs] btrfs_find_all_roots_safe+0xa8/0x120 [btrfs] btrfs_find_all_roots+0x57/0x70 [btrfs] btrfs_qgroup_trace_extent_post+0x37/0x70 [btrfs] btrfs_qgroup_trace_leaf_items+0x10b/0x140 [btrfs] btrfs_qgroup_trace_subtree+0xc8/0xe0 [btrfs] do_walk_down+0x541/0x5e3 [btrfs] walk_down_tree+0xab/0xe7 [btrfs] btrfs_drop_snapshot+0x356/0x71a [btrfs] btrfs_clean_one_deleted_snapshot+0xb8/0xf0 [btrfs] cleaner_kthread+0x12b/0x160 [btrfs] kthread+0x112/0x130 ret_from_fork+0x27/0x50 When dropping snapshots with qgroup enabled, we will trigger backref walk. However such backref walk at that timing is pretty dangerous, as if one of the parent nodes get WRITE locked by other thread, we could cause a dead lock. For example: FS 260 FS 261 (Dropped) node A node B / \ / \ node C node D node E / \ / \ / \ leaf F|leaf G|leaf H|leaf I|leaf J|leaf K The lock sequence would be: Thread A (cleaner) | Thread B (other writer) ----------------------------------------------------------------------- write_lock(B) | write_lock(D) | ^^^ called by walk_down_tree() | | write_lock(A) | write_lock(D) << Stall read_lock(H) << for backref walk | read_lock(D) << lock owner is | the same thread A | so read lock is OK | read_lock(A) << Stall | So thread A hold write lock D, and needs read lock A to unlock. While thread B holds write lock A, while needs lock D to unlock. This will cause a deadlock. This is not only limited to snapshot dropping case. As the backref walk, even only happens on commit trees, is breaking the normal top-down locking order, makes it deadlock prone. Fixes: fb235dc0 ("btrfs: qgroup: Move half of the qgroup accounting time out of commit trans") CC: stable@vger.kernel.org # 4.14+ Reported-and-tested-by: NDavid Sterba <dsterba@suse.com> Reported-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NQu Wenruo <wqu@suse.com> Signed-off-by: NJosef Bacik <josef@toxicpanda.com> Reviewed-by: NFilipe Manana <fdmanana@suse.com> [ rebase to latest branch and fix lock assert bug in btrfs/007 ] [ backport to linux-4.19.y branch, solve minor conflicts ] Signed-off-by: NQu Wenruo <wqu@suse.com> [ copy logs and deadlock analysis from Qu's patch ] Signed-off-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 22 5月, 2019 2 次提交
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由 Filipe Manana 提交于
commit bfc61c36260ca990937539cd648ede3cd749bc10 upstream. When finding out which inodes have references on a particular extent, done by backref.c:iterate_extent_inodes(), from the BTRFS_IOC_LOGICAL_INO (both v1 and v2) ioctl and from scrub we use the transaction join API to grab a reference on the currently running transaction, since in order to give accurate results we need to inspect the delayed references of the currently running transaction. However, if there is currently no running transaction, the join operation will create a new transaction. This is inefficient as the transaction will eventually be committed, doing unnecessary IO and introducing a potential point of failure that will lead to a transaction abort due to -ENOSPC, as recently reported [1]. That's because the join, creates the transaction but does not reserve any space, so when attempting to update the root item of the root passed to btrfs_join_transaction(), during the transaction commit, we can end up failling with -ENOSPC. Users of a join operation are supposed to actually do some filesystem changes and reserve space by some means, which is not the case of iterate_extent_inodes(), it is a read-only operation for all contextes from which it is called. The reported [1] -ENOSPC failure stack trace is the following: heisenberg kernel: ------------[ cut here ]------------ heisenberg kernel: BTRFS: Transaction aborted (error -28) heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068 heisenberg kernel: FS: 0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000 heisenberg kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 heisenberg kernel: Call Trace: heisenberg kernel: commit_fs_roots+0x166/0x1d0 [btrfs] heisenberg kernel: ? _cond_resched+0x15/0x30 heisenberg kernel: ? btrfs_run_delayed_refs+0xac/0x180 [btrfs] heisenberg kernel: btrfs_commit_transaction+0x2bd/0x870 [btrfs] heisenberg kernel: ? start_transaction+0x9d/0x3f0 [btrfs] heisenberg kernel: transaction_kthread+0x147/0x180 [btrfs] heisenberg kernel: ? btrfs_cleanup_transaction+0x530/0x530 [btrfs] heisenberg kernel: kthread+0x112/0x130 heisenberg kernel: ? kthread_bind+0x30/0x30 heisenberg kernel: ret_from_fork+0x35/0x40 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]--- So fix that by using the attach API, which does not create a transaction when there is currently no running transaction. [1] https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/Reported-by: NZygo Blaxell <ce3g8jdj@umail.furryterror.org> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Filipe Manana 提交于
commit 03628cdbc64db6262e50d0357960a4e9562676a1 upstream. During fiemap, for regular extents (non inline) we need to check if they are shared and if they are, set the shared bit. Checking if an extent is shared requires checking the delayed references of the currently running transaction, since some reference might have not yet hit the extent tree and be only in the in-memory delayed references. However we were using a transaction join for this, which creates a new transaction when there is no transaction currently running. That means that two more potential failures can happen: creating the transaction and committing it. Further, if no write activity is currently happening in the system, and fiemap calls keep being done, we end up creating and committing transactions that do nothing. In some extreme cases this can result in the commit of the transaction created by fiemap to fail with ENOSPC when updating the root item of a subvolume tree because a join does not reserve any space, leading to a trace like the following: heisenberg kernel: ------------[ cut here ]------------ heisenberg kernel: BTRFS: Transaction aborted (error -28) heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068 heisenberg kernel: FS: 0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000 heisenberg kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 heisenberg kernel: Call Trace: heisenberg kernel: commit_fs_roots+0x166/0x1d0 [btrfs] heisenberg kernel: ? _cond_resched+0x15/0x30 heisenberg kernel: ? btrfs_run_delayed_refs+0xac/0x180 [btrfs] heisenberg kernel: btrfs_commit_transaction+0x2bd/0x870 [btrfs] heisenberg kernel: ? start_transaction+0x9d/0x3f0 [btrfs] heisenberg kernel: transaction_kthread+0x147/0x180 [btrfs] heisenberg kernel: ? btrfs_cleanup_transaction+0x530/0x530 [btrfs] heisenberg kernel: kthread+0x112/0x130 heisenberg kernel: ? kthread_bind+0x30/0x30 heisenberg kernel: ret_from_fork+0x35/0x40 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]--- Since fiemap (and btrfs_check_shared()) is a read-only operation, do not do a transaction join to avoid the overhead of creating a new transaction (if there is currently no running transaction) and introducing a potential point of failure when the new transaction gets committed, instead use a transaction attach to grab a handle for the currently running transaction if any. Reported-by: NChristoph Anton Mitterer <calestyo@scientia.net> Link: https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/ Fixes: afce772e ("btrfs: fix check_shared for fiemap ioctl") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: NQu Wenruo <wqu@suse.com> Signed-off-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 06 8月, 2018 2 次提交
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由 Misono Tomohiro 提交于
Use ERR_CAST() instead of void * to make meaning clear. Signed-off-by: NMisono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: NNikolay Borisov <nborisov@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Su Yue 提交于
If type of extent_inline_ref found is not expected, filesystem may have been corrupted, should return EUCLEAN instead of EINVAL. Signed-off-by: NSu Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 12 4月, 2018 1 次提交
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由 David Sterba 提交于
Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 31 3月, 2018 2 次提交
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由 Qu Wenruo 提交于
We have several reports about node pointer points to incorrect child tree blocks, which could have even wrong owner and level but still with valid generation and checksum. Although btrfs check could handle it and print error message like: leaf parent key incorrect 60670574592 Kernel doesn't have enough check on this type of corruption correctly. At least add such check to read_tree_block() and btrfs_read_buffer(), where we need two new parameters @level and @first_key to verify the child tree block. The new @level check is mandatory and all call sites are already modified to extract expected level from its call chain. While @first_key is optional, the following call sites are skipping such check: 1) Root node/leaf As ROOT_ITEM doesn't contain the first key, skip @first_key check. 2) Direct backref Only parent bytenr and level is known and we need to resolve the key all by ourselves, skip @first_key check. Another note of this verification is, it needs extra info from nodeptr or ROOT_ITEM, so it can't fit into current tree-checker framework, which is limited to node/leaf boundary. Signed-off-by: NQu Wenruo <wqu@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Nikolay Borisov 提交于
Added as part of 86d5f994 ("btrfs: convert prelimary reference tracking to use rbtrees") but never used. tmp_op_key essentially subsumed that variable. Signed-off-by: NNikolay Borisov <nborisov@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 26 3月, 2018 1 次提交
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由 David Sterba 提交于
The __cold functions are placed to a special section, as they're expected to be called rarely. This could help i-cache prefetches or help compiler to decide which branches are more/less likely to be taken without any other annotations needed. Though we can't add more __exit annotations, it's still possible to add __cold (that's also added with __exit). That way the following function categories are tagged: - printf wrappers, error messages - exit helpers Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 15 3月, 2018 1 次提交
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由 Edmund Nadolski 提交于
This patch addresses an issue that causes fiemap to falsely report a shared extent. The test case is as follows: xfs_io -f -d -c "pwrite -b 16k 0 64k" -c "fiemap -v" /media/scratch/file5 sync xfs_io -c "fiemap -v" /media/scratch/file5 which gives the resulting output: wrote 65536/65536 bytes at offset 0 64 KiB, 4 ops; 0.0000 sec (121.359 MiB/sec and 7766.9903 ops/sec) /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x2001 /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x1 This is because btrfs_check_shared calls find_parent_nodes repeatedly in a loop, passing a share_check struct to report the count of shared extent. But btrfs_check_shared does not re-initialize the count value to zero for subsequent calls from the loop, resulting in a false share count value. This is a regressive behavior from 4.13. With proper re-initialization the test result is as follows: wrote 65536/65536 bytes at offset 0 64 KiB, 4 ops; 0.0000 sec (110.035 MiB/sec and 7042.2535 ops/sec) /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x1 /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x1 which corrects the regression. Fixes: 3ec4d323 ("btrfs: allow backref search checks for shared extents") Signed-off-by: NEdmund Nadolski <enadolski@suse.com> [ add text from cover letter to changelog ] Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 02 2月, 2018 1 次提交
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由 Zygo Blaxell 提交于
Until v4.14, this warning was very infrequent: WARNING: CPU: 3 PID: 18172 at fs/btrfs/backref.c:1391 find_parent_nodes+0xc41/0x14e0 Modules linked in: [...] CPU: 3 PID: 18172 Comm: bees Tainted: G D W L 4.11.9-zb64+ #1 Hardware name: System manufacturer System Product Name/M5A78L-M/USB3, BIOS 2101 12/02/2014 Call Trace: dump_stack+0x85/0xc2 __warn+0xd1/0xf0 warn_slowpath_null+0x1d/0x20 find_parent_nodes+0xc41/0x14e0 __btrfs_find_all_roots+0xad/0x120 ? extent_same_check_offsets+0x70/0x70 iterate_extent_inodes+0x168/0x300 iterate_inodes_from_logical+0x87/0xb0 ? iterate_inodes_from_logical+0x87/0xb0 ? extent_same_check_offsets+0x70/0x70 btrfs_ioctl+0x8ac/0x2820 ? lock_acquire+0xc2/0x200 do_vfs_ioctl+0x91/0x700 ? __fget+0x112/0x200 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc6 ? trace_hardirqs_off_caller+0x1f/0x140 Starting with v4.14 (specifically 86d5f994 ("btrfs: convert prelimary reference tracking to use rbtrees")) the WARN_ON occurs three orders of magnitude more frequently--almost once per second while running workloads like bees. Replace the WARN_ON() with a comment rationale for its removal. The rationale is paraphrased from an explanation by Edmund Nadolski <enadolski@suse.de> on the linux-btrfs mailing list. Fixes: 8da6d581 ("Btrfs: added btrfs_find_all_roots()") Signed-off-by: NZygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: NLu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 22 1月, 2018 1 次提交
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由 Colin Ian King 提交于
The function update_share_count is local to the source and does not need to be in global scope, so make it static. Cleans up sparse warning: fs/btrfs/backref.c:219:6: warning: symbol 'update_share_count' was not declared. Should it be static? Signed-off-by: NColin Ian King <colin.king@canonical.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 02 11月, 2017 2 次提交
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由 Josef Bacik 提交于
If we get a significant amount of delayed refs for a single block (think modifying multiple snapshots) we can end up spending an ungodly amount of time looping through all of the entries trying to see if they can be merged. This is because we only add them to a list, so we have O(2n) for every ref head. This doesn't make any sense as we likely have refs for different roots, and so they cannot be merged. Tracking in a tree will allow us to break as soon as we hit an entry that doesn't match, making our worst case O(n). With this we can also merge entries more easily. Before we had to hope that matching refs were on the ends of our list, but with the tree we can search down to exact matches and merge them at insert time. Signed-off-by: NJosef Bacik <jbacik@fb.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Zygo Blaxell 提交于
The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and offset (encoded as a single logical address) to a list of extent refs. LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping (extent ref -> extent bytenr and offset, or logical address). These are useful capabilities for programs that manipulate extents and extent references from userspace (e.g. dedup and defrag utilities). When the extents are uncompressed (and not encrypted and not other), check_extent_in_eb performs filtering of the extent refs to remove any extent refs which do not contain the same extent offset as the 'logical' parameter's extent offset. This prevents LOGICAL_INO from returning references to more than a single block. To find the set of extent references to an uncompressed extent from [a, b), userspace has to run a loop like this pseudocode: for (i = a; i < b; ++i) extent_ref_set += LOGICAL_INO(i); At each iteration of the loop (up to 32768 iterations for a 128M extent), data we are interested in is collected in the kernel, then deleted by the filter in check_extent_in_eb. When the extents are compressed (or encrypted or other), the 'logical' parameter must be an extent bytenr (the 'a' parameter in the loop). No filtering by extent offset is done (or possible?) so the result is the complete set of extent refs for the entire extent. This removes the need for the loop, since we get all the extent refs in one call. Add an 'ignore_offset' argument to iterate_inodes_from_logical, [...several levels of function call graph...], and check_extent_in_eb, so that we can disable the extent offset filtering for uncompressed extents. This flag can be set by an improved version of the LOGICAL_INO ioctl to get either behavior as desired. There is no functional change in this patch. The new flag is always false. Signed-off-by: NZygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: NDavid Sterba <dsterba@suse.com> [ minor coding style fixes ] Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 30 10月, 2017 1 次提交
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由 Josef Bacik 提交于
This is just excessive information in the ref_head, and makes the code complicated. It is a relic from when we had the heads and the refs in the same tree, which is no longer the case. With this removal I've cleaned up a bunch of the cruft around this old assumption as well. Signed-off-by: NJosef Bacik <jbacik@fb.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 21 8月, 2017 1 次提交
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由 Liu Bo 提交于
Since we have a helper which can do sanity check, this converts all btrfs_extent_inline_ref_type to it. Signed-off-by: NLiu Bo <bo.li.liu@oracle.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 16 8月, 2017 11 次提交
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由 Edmund Nadolski 提交于
Repeating the same computation in multiple places is not necessary. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Edmund Nadolski 提交于
When called with a struct share_check, find_parent_nodes() will detect a shared extent and immediately return with BACKREF_SHARED_FOUND. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NLiu Bo <bo.li.liu@oracle.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Edmund Nadolski 提交于
Since backref resolution is CPU-intensive, the cond_resched calls should help alleviate soft lockup occurences. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
This patch adds a tracepoint event for prelim_ref insertion and merging. For each, the ref being inserted or merged and the count of tree nodes is issued. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
This patch adds counters to each of the rbtrees so that we can tell how large they are growing for a given workload. These counters will be exported by tracepoints in the next patch. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Edmund Nadolski 提交于
It's been known for a while that the use of multiple lists that are periodically merged was an algorithmic problem within btrfs. There are several workloads that don't complete in any reasonable amount of time (e.g. btrfs/130) and others that cause soft lockups. The solution is to use a set of rbtrees that do insertion merging for both indirect and direct refs, with the former converting refs into the latter. The result is a btrfs/130 workload that used to take several hours now takes about half of that. This runtime still isn't acceptable and a future patch will address that by moving the rbtrees higher in the stack so the lookups can be shared across multiple calls to find_parent_nodes. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NLiu Bo <bo.li.liu@oracle.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Edmund Nadolski 提交于
Commit afce772e ("btrfs: fix check_shared for fiemap ioctl") added the ref_tree code in backref.c to reduce backref searching for shared extents under the FIEMAP ioctl. This code will not be compatible with the upcoming rbtree changes for improved backref searching, so this patch removes the ref_tree code. The rbtree changes will provide the equivalent functionality for FIEMAP. The above commit also introduced transaction semantics around calls to btrfs_check_shared() in order to accurately account for delayed refs. This functionality needs to be retained, so a complete revert of the above commit is not desirable. This patch therefore removes the ref_tree portion of the commit as above, however it does not remove the transaction portion. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Edmund Nadolski 提交于
Commit afce772e ("btrfs: fix check_shared for fiemap ioctl") added transaction semantics around calls to btrfs_check_shared() in order to provide accurate accounting of delayed refs. The transaction management should be done inside btrfs_check_shared(), so that callers do not need to manage transactions individually. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
We typically use __ to indicate a helper routine that shouldn't be called directly without understanding the proper context required to do so. We use static functions to indicate that a function is private to a particular C file. The backref code uses static function and __ prefixes on nearly everything, which makes the code difficult to read and establishes a pattern for future code that shouldn't be followed. This patch drops all the unnecessary prefixes. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
Replacing the double cast and ternary conditional with a helper makes the code easier on the eyes. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
This constifies a few buffers used in the backref code. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 20 6月, 2017 1 次提交
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由 David Sterba 提交于
Now that init_ipath is called either from a safe context or with memalloc_nofs protection, we can switch to GFP_KERNEL allocations in init_path and init_data_container. Reviewed-by: NAnand Jain <anand.jain@oracle.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 18 4月, 2017 3 次提交
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由 Edmund Nadolski 提交于
Define the SEQ_LAST macro to replace (u64)-1 in places where said value triggers a special-case ref search behavior. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Reviewed-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NQu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Edmund Nadolski 提交于
Replace hardcoded numeric values for __merge_refs 'mode' argument with descriptive constants. Signed-off-by: NEdmund Nadolski <enadolski@suse.com> Reviewed-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Elena Reshetova 提交于
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: NElena Reshetova <elena.reshetova@intel.com> Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com> Signed-off-by: NKees Cook <keescook@chromium.org> Signed-off-by: NDavid Windsor <dwindsor@gmail.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 17 2月, 2017 1 次提交
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由 David Sterba 提交于
Never used. Reviewed-by: NLiu Bo <bo.li.liu@oracle.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 14 2月, 2017 1 次提交
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由 Liu Bo 提交于
All we need is @delayed_refs, all callers have get it ahead of calling btrfs_find_delayed_ref_head since lock needs to be acquired firstly, there is no reason to deference it again inside the function. Signed-off-by: NLiu Bo <bo.li.liu@oracle.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 06 12月, 2016 3 次提交
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由 Jeff Mahoney 提交于
Now we only use the root parameter to print the root objectid in a tracepoint. We can use the root parameter from the transaction handle for that. It's also used to join the transaction with async commits, so we remove the comment that it's just for checking. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
There are loads of functions in btrfs that accept a root parameter but only use it to obtain an fs_info pointer. Let's convert those to just accept an fs_info pointer directly. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
We track the node sizes per-root, but they never vary from the values in the superblock. This patch messes with the 80-column style a bit, but subsequent patches to factor out root->fs_info into a convenience variable fix it up again. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 27 9月, 2016 2 次提交
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由 Jeff Mahoney 提交于
For many printks, we want to know which file system issued the message. This patch converts most pr_* calls to use the btrfs_* versions instead. In some cases, this means adding plumbing to allow call sites access to an fs_info pointer. fs/btrfs/check-integrity.c is left alone for another day. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Jeff Mahoney 提交于
CodingStyle chapter 2: "[...] never break user-visible strings such as printk messages, because that breaks the ability to grep for them." This patch unsplits user-visible strings. Signed-off-by: NJeff Mahoney <jeffm@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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- 26 9月, 2016 1 次提交
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由 Lu Fengqi 提交于
Only in the case of different root_id or different object_id, check_shared identified extent as the shared. However, If a extent was referred by different offset of same file, it should also be identified as shared. In addition, check_shared's loop scale is at least n^3, so if a extent has too many references, even causes soft hang up. First, add all delayed_ref to the ref_tree and calculate the unqiue_refs, if the unique_refs is greater than one, return BACKREF_FOUND_SHARED. Then individually add the on-disk reference(inline/keyed) to the ref_tree and calculate the unique_refs of the ref_tree to check if the unique_refs is greater than one.Because once there are two references to return SHARED, so the time complexity is close to the constant. Reported-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: NLu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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