This is a note to let you know that I've just added the patch titled f2fs: use spin_{,un}lock_irq{save,restore} to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: f2fs-use-spin_-un-lock_irq-save-restore.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d1aa245354ae4605d1183f542ed8d45811c439f6 Mon Sep 17 00:00:00 2001 From: Chao Yu <yuchao0@xxxxxxxxxx> Date: Fri, 7 Jul 2017 14:10:15 +0800 Subject: f2fs: use spin_{,un}lock_irq{save,restore} From: Chao Yu <yuchao0@xxxxxxxxxx> commit d1aa245354ae4605d1183f542ed8d45811c439f6 upstream. generic/361 reports below warning, this is because: once, there is someone entering into critical region of sbi.cp_lock, if write_end_io. f2fs_stop_checkpoint is invoked from an triggered IRQ, we will encounter deadlock. So this patch changes to use spin_{,un}lock_irq{save,restore} to create critical region without IRQ enabled to avoid potential deadlock. irq event stamp: 83391573 loop: Write error at byte offset 438729728, length 1024. hardirqs last enabled at (83391573): [<c1809752>] restore_all+0xf/0x65 hardirqs last disabled at (83391572): [<c1809eac>] reschedule_interrupt+0x30/0x3c loop: Write error at byte offset 438860288, length 1536. softirqs last enabled at (83389244): [<c180cc4e>] __do_softirq+0x1ae/0x476 softirqs last disabled at (83389237): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40 loop: Write error at byte offset 438990848, length 2048. ================================ WARNING: inconsistent lock state 4.12.0-rc2+ #30 Tainted: G O -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. xfs_io/7959 [HC1[1]:SC0[0]:HE0:SE1] takes: (&(&sbi->cp_lock)->rlock){?.+...}, at: [<f96f96cc>] f2fs_stop_checkpoint+0x1c/0x50 [f2fs] {HARDIRQ-ON-W} state was registered at: __lock_acquire+0x527/0x7b0 lock_acquire+0xae/0x220 _raw_spin_lock+0x42/0x50 do_checkpoint+0x165/0x9e0 [f2fs] write_checkpoint+0x33f/0x740 [f2fs] __f2fs_sync_fs+0x92/0x1f0 [f2fs] f2fs_sync_fs+0x12/0x20 [f2fs] sync_filesystem+0x67/0x80 generic_shutdown_super+0x27/0x100 kill_block_super+0x22/0x50 kill_f2fs_super+0x3a/0x40 [f2fs] deactivate_locked_super+0x3d/0x70 deactivate_super+0x40/0x60 cleanup_mnt+0x39/0x70 __cleanup_mnt+0x10/0x20 task_work_run+0x69/0x80 exit_to_usermode_loop+0x57/0x85 do_fast_syscall_32+0x18c/0x1b0 entry_SYSENTER_32+0x4c/0x7b irq event stamp: 1957420 hardirqs last enabled at (1957419): [<c1808f37>] _raw_spin_unlock_irq+0x27/0x50 hardirqs last disabled at (1957420): [<c1809f9c>] call_function_single_interrupt+0x30/0x3c softirqs last enabled at (1953784): [<c180cc4e>] __do_softirq+0x1ae/0x476 softirqs last disabled at (1953773): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&sbi->cp_lock)->rlock); <Interrupt> lock(&(&sbi->cp_lock)->rlock); *** DEADLOCK *** 2 locks held by xfs_io/7959: #0: (sb_writers#13){.+.+.+}, at: [<c11fd7ca>] vfs_write+0x16a/0x190 #1: (&sb->s_type->i_mutex_key#16){+.+.+.}, at: [<f96e33f5>] f2fs_file_write_iter+0x25/0x140 [f2fs] stack backtrace: CPU: 2 PID: 7959 Comm: xfs_io Tainted: G O 4.12.0-rc2+ #30 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 Call Trace: dump_stack+0x5f/0x92 print_usage_bug+0x1d3/0x1dd ? check_usage_backwards+0xe0/0xe0 mark_lock+0x23d/0x280 __lock_acquire+0x699/0x7b0 ? __this_cpu_preempt_check+0xf/0x20 ? trace_hardirqs_off_caller+0x91/0xe0 lock_acquire+0xae/0x220 ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs] _raw_spin_lock+0x42/0x50 ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs] f2fs_stop_checkpoint+0x1c/0x50 [f2fs] f2fs_write_end_io+0x147/0x150 [f2fs] bio_endio+0x7a/0x1e0 blk_update_request+0xad/0x410 blk_mq_end_request+0x16/0x60 lo_complete_rq+0x3c/0x70 __blk_mq_complete_request_remote+0x11/0x20 flush_smp_call_function_queue+0x6d/0x120 ? debug_smp_processor_id+0x12/0x20 generic_smp_call_function_single_interrupt+0x12/0x30 smp_call_function_single_interrupt+0x25/0x40 call_function_single_interrupt+0x37/0x3c EIP: _raw_spin_unlock_irq+0x2d/0x50 EFLAGS: 00000296 CPU: 2 EAX: 00000001 EBX: d2ccc51c ECX: 00000001 EDX: c1aacebd ESI: 00000000 EDI: 00000000 EBP: c96c9d1c ESP: c96c9d18 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 ? inherit_task_group.isra.98.part.99+0x6b/0xb0 __add_to_page_cache_locked+0x1d4/0x290 add_to_page_cache_lru+0x38/0xb0 pagecache_get_page+0x8e/0x200 f2fs_write_begin+0x96/0xf00 [f2fs] ? trace_hardirqs_on_caller+0xdd/0x1c0 ? current_time+0x17/0x50 ? trace_hardirqs_on+0xb/0x10 generic_perform_write+0xa9/0x170 __generic_file_write_iter+0x1a2/0x1f0 ? f2fs_preallocate_blocks+0x137/0x160 [f2fs] f2fs_file_write_iter+0x6e/0x140 [f2fs] ? __lock_acquire+0x429/0x7b0 __vfs_write+0xc1/0x140 vfs_write+0x9b/0x190 SyS_pwrite64+0x63/0xa0 do_fast_syscall_32+0xa1/0x1b0 entry_SYSENTER_32+0x4c/0x7b EIP: 0xb7786c61 EFLAGS: 00000293 CPU: 2 EAX: ffffffda EBX: 00000003 ECX: 08416000 EDX: 00001000 ESI: 18b24000 EDI: 00000000 EBP: 00000003 ESP: bf9b36b0 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b Fixes: aaec2b1d1879 ("f2fs: introduce cp_lock to protect updating of ckpt_flags") Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/f2fs/checkpoint.c | 11 ++++++----- fs/f2fs/f2fs.h | 18 ++++++++++++------ 2 files changed, 18 insertions(+), 11 deletions(-) --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -1051,8 +1051,9 @@ static void update_ckpt_flags(struct f2f { unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num; struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi); + unsigned long flags; - spin_lock(&sbi->cp_lock); + spin_lock_irqsave(&sbi->cp_lock, flags); if ((cpc->reason & CP_UMOUNT) && le32_to_cpu(ckpt->cp_pack_total_block_count) > @@ -1083,14 +1084,14 @@ static void update_ckpt_flags(struct f2f /* set this flag to activate crc|cp_ver for recovery */ __set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG); - spin_unlock(&sbi->cp_lock); + spin_unlock_irqrestore(&sbi->cp_lock, flags); } static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) { struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi); struct f2fs_nm_info *nm_i = NM_I(sbi); - unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num; + unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num, flags; block_t start_blk; unsigned int data_sum_blocks, orphan_blocks; __u32 crc32 = 0; @@ -1132,12 +1133,12 @@ static int do_checkpoint(struct f2fs_sb_ /* 2 cp + n data seg summary + orphan inode blocks */ data_sum_blocks = npages_for_summary_flush(sbi, false); - spin_lock(&sbi->cp_lock); + spin_lock_irqsave(&sbi->cp_lock, flags); if (data_sum_blocks < NR_CURSEG_DATA_TYPE) __set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG); else __clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG); - spin_unlock(&sbi->cp_lock); + spin_unlock_irqrestore(&sbi->cp_lock, flags); orphan_blocks = GET_ORPHAN_BLOCKS(orphan_num); ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks + --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1228,9 +1228,11 @@ static inline void __set_ckpt_flags(stru static inline void set_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f) { - spin_lock(&sbi->cp_lock); + unsigned long flags; + + spin_lock_irqsave(&sbi->cp_lock, flags); __set_ckpt_flags(F2FS_CKPT(sbi), f); - spin_unlock(&sbi->cp_lock); + spin_unlock_irqrestore(&sbi->cp_lock, flags); } static inline void __clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f) @@ -1244,22 +1246,26 @@ static inline void __clear_ckpt_flags(st static inline void clear_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f) { - spin_lock(&sbi->cp_lock); + unsigned long flags; + + spin_lock_irqsave(&sbi->cp_lock, flags); __clear_ckpt_flags(F2FS_CKPT(sbi), f); - spin_unlock(&sbi->cp_lock); + spin_unlock_irqrestore(&sbi->cp_lock, flags); } static inline void disable_nat_bits(struct f2fs_sb_info *sbi, bool lock) { + unsigned long flags; + set_sbi_flag(sbi, SBI_NEED_FSCK); if (lock) - spin_lock(&sbi->cp_lock); + spin_lock_irqsave(&sbi->cp_lock, flags); __clear_ckpt_flags(F2FS_CKPT(sbi), CP_NAT_BITS_FLAG); kfree(NM_I(sbi)->nat_bits); NM_I(sbi)->nat_bits = NULL; if (lock) - spin_unlock(&sbi->cp_lock); + spin_unlock_irqrestore(&sbi->cp_lock, flags); } static inline bool enabled_nat_bits(struct f2fs_sb_info *sbi, Patches currently in stable-queue which might be from yuchao0@xxxxxxxxxx are queue-4.12/f2fs-don-t-clear-sgid-when-inheriting-acls.patch queue-4.12/f2fs-use-spin_-un-lock_irq-save-restore.patch queue-4.12/f2fs-sanity-check-size-of-nat-and-sit-cache.patch queue-4.12/f2fs-wake-up-all-waiters-in-f2fs_submit_discard_endio.patch queue-4.12/f2fs-do-not-issue-small-discards-in-lfs-mode.patch