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chaseyuJaegeuk Kim
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Jaegeuk Kim
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f2fs: use spin_{,un}lock_irq{save,restore}
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: aaec2b1 ("f2fs: introduce cp_lock to protect updating of ckpt_flags") Cc: [email protected] Signed-off-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]>
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-11
lines changed

fs/f2fs/checkpoint.c

Lines changed: 6 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -1053,8 +1053,9 @@ static void update_ckpt_flags(struct f2fs_sb_info *sbi, struct cp_control *cpc)
10531053
{
10541054
unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num;
10551055
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1056+
unsigned long flags;
10561057

1057-
spin_lock(&sbi->cp_lock);
1058+
spin_lock_irqsave(&sbi->cp_lock, flags);
10581059

10591060
if ((cpc->reason & CP_UMOUNT) &&
10601061
le32_to_cpu(ckpt->cp_pack_total_block_count) >
@@ -1085,14 +1086,14 @@ static void update_ckpt_flags(struct f2fs_sb_info *sbi, struct cp_control *cpc)
10851086
/* set this flag to activate crc|cp_ver for recovery */
10861087
__set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG);
10871088

1088-
spin_unlock(&sbi->cp_lock);
1089+
spin_unlock_irqrestore(&sbi->cp_lock, flags);
10891090
}
10901091

10911092
static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
10921093
{
10931094
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
10941095
struct f2fs_nm_info *nm_i = NM_I(sbi);
1095-
unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num;
1096+
unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num, flags;
10961097
block_t start_blk;
10971098
unsigned int data_sum_blocks, orphan_blocks;
10981099
__u32 crc32 = 0;
@@ -1134,12 +1135,12 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
11341135

11351136
/* 2 cp + n data seg summary + orphan inode blocks */
11361137
data_sum_blocks = npages_for_summary_flush(sbi, false);
1137-
spin_lock(&sbi->cp_lock);
1138+
spin_lock_irqsave(&sbi->cp_lock, flags);
11381139
if (data_sum_blocks < NR_CURSEG_DATA_TYPE)
11391140
__set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
11401141
else
11411142
__clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
1142-
spin_unlock(&sbi->cp_lock);
1143+
spin_unlock_irqrestore(&sbi->cp_lock, flags);
11431144

11441145
orphan_blocks = GET_ORPHAN_BLOCKS(orphan_num);
11451146
ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks +

fs/f2fs/f2fs.h

Lines changed: 12 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -1254,9 +1254,11 @@ static inline void __set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
12541254

12551255
static inline void set_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
12561256
{
1257-
spin_lock(&sbi->cp_lock);
1257+
unsigned long flags;
1258+
1259+
spin_lock_irqsave(&sbi->cp_lock, flags);
12581260
__set_ckpt_flags(F2FS_CKPT(sbi), f);
1259-
spin_unlock(&sbi->cp_lock);
1261+
spin_unlock_irqrestore(&sbi->cp_lock, flags);
12601262
}
12611263

12621264
static inline void __clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
@@ -1270,22 +1272,26 @@ static inline void __clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f
12701272

12711273
static inline void clear_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
12721274
{
1273-
spin_lock(&sbi->cp_lock);
1275+
unsigned long flags;
1276+
1277+
spin_lock_irqsave(&sbi->cp_lock, flags);
12741278
__clear_ckpt_flags(F2FS_CKPT(sbi), f);
1275-
spin_unlock(&sbi->cp_lock);
1279+
spin_unlock_irqrestore(&sbi->cp_lock, flags);
12761280
}
12771281

12781282
static inline void disable_nat_bits(struct f2fs_sb_info *sbi, bool lock)
12791283
{
1284+
unsigned long flags;
1285+
12801286
set_sbi_flag(sbi, SBI_NEED_FSCK);
12811287

12821288
if (lock)
1283-
spin_lock(&sbi->cp_lock);
1289+
spin_lock_irqsave(&sbi->cp_lock, flags);
12841290
__clear_ckpt_flags(F2FS_CKPT(sbi), CP_NAT_BITS_FLAG);
12851291
kfree(NM_I(sbi)->nat_bits);
12861292
NM_I(sbi)->nat_bits = NULL;
12871293
if (lock)
1288-
spin_unlock(&sbi->cp_lock);
1294+
spin_unlock_irqrestore(&sbi->cp_lock, flags);
12891295
}
12901296

12911297
static inline bool enabled_nat_bits(struct f2fs_sb_info *sbi,

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