This is a note to let you know that I've just added the patch titled f2fs: use spin_lock to avoid hang to the 5.15-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_lock-to-avoid-hang.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 038c054efc225a29e35d2d0cdde24cc3b934c4ac Author: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Date: Mon Mar 7 17:27:46 2022 -0800 f2fs: use spin_lock to avoid hang [ Upstream commit 98237fcda4a24e67b0a4498c17d5aa4ad4537bc7 ] [14696.634553] task:cat state:D stack: 0 pid:1613738 ppid:1613735 flags:0x00000004 [14696.638285] Call Trace: [14696.639038] <TASK> [14696.640032] __schedule+0x302/0x930 [14696.640969] schedule+0x58/0xd0 [14696.641799] schedule_preempt_disabled+0x18/0x30 [14696.642890] __mutex_lock.constprop.0+0x2fb/0x4f0 [14696.644035] ? mod_objcg_state+0x10c/0x310 [14696.645040] ? obj_cgroup_charge+0xe1/0x170 [14696.646067] __mutex_lock_slowpath+0x13/0x20 [14696.647126] mutex_lock+0x34/0x40 [14696.648070] stat_show+0x25/0x17c0 [f2fs] [14696.649218] seq_read_iter+0x120/0x4b0 [14696.650289] ? aa_file_perm+0x12a/0x500 [14696.651357] ? lru_cache_add+0x1c/0x20 [14696.652470] seq_read+0xfd/0x140 [14696.653445] full_proxy_read+0x5c/0x80 [14696.654535] vfs_read+0xa0/0x1a0 [14696.655497] ksys_read+0x67/0xe0 [14696.656502] __x64_sys_read+0x1a/0x20 [14696.657580] do_syscall_64+0x3b/0xc0 [14696.658671] entry_SYSCALL_64_after_hwframe+0x44/0xae [14696.660068] RIP: 0033:0x7efe39df1cb2 [14696.661133] RSP: 002b:00007ffc8badd948 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [14696.662958] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007efe39df1cb2 [14696.664757] RDX: 0000000000020000 RSI: 00007efe399df000 RDI: 0000000000000003 [14696.666542] RBP: 00007efe399df000 R08: 00007efe399de010 R09: 00007efe399de010 [14696.668363] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000 [14696.670155] R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 [14696.671965] </TASK> [14696.672826] task:umount state:D stack: 0 pid:1614985 ppid:1614984 flags:0x00004000 [14696.674930] Call Trace: [14696.675903] <TASK> [14696.676780] __schedule+0x302/0x930 [14696.677927] schedule+0x58/0xd0 [14696.679019] schedule_preempt_disabled+0x18/0x30 [14696.680412] __mutex_lock.constprop.0+0x2fb/0x4f0 [14696.681783] ? destroy_inode+0x65/0x80 [14696.683006] __mutex_lock_slowpath+0x13/0x20 [14696.684305] mutex_lock+0x34/0x40 [14696.685442] f2fs_destroy_stats+0x1e/0x60 [f2fs] [14696.686803] f2fs_put_super+0x158/0x390 [f2fs] [14696.688238] generic_shutdown_super+0x7a/0x120 [14696.689621] kill_block_super+0x27/0x50 [14696.690894] kill_f2fs_super+0x7f/0x100 [f2fs] [14696.692311] deactivate_locked_super+0x35/0xa0 [14696.693698] deactivate_super+0x40/0x50 [14696.694985] cleanup_mnt+0x139/0x190 [14696.696209] __cleanup_mnt+0x12/0x20 [14696.697390] task_work_run+0x64/0xa0 [14696.698587] exit_to_user_mode_prepare+0x1b7/0x1c0 [14696.700053] syscall_exit_to_user_mode+0x27/0x50 [14696.701418] do_syscall_64+0x48/0xc0 [14696.702630] entry_SYSCALL_64_after_hwframe+0x44/0xae Reviewed-by: Chao Yu <chao@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c index 07ad0d81f0c5..b449c7a372a4 100644 --- a/fs/f2fs/debug.c +++ b/fs/f2fs/debug.c @@ -21,7 +21,7 @@ #include "gc.h" static LIST_HEAD(f2fs_stat_list); -static DEFINE_MUTEX(f2fs_stat_mutex); +static DEFINE_RAW_SPINLOCK(f2fs_stat_lock); #ifdef CONFIG_DEBUG_FS static struct dentry *f2fs_debugfs_root; #endif @@ -345,8 +345,9 @@ static int stat_show(struct seq_file *s, void *v) { struct f2fs_stat_info *si; int i = 0, j = 0; + unsigned long flags; - mutex_lock(&f2fs_stat_mutex); + raw_spin_lock_irqsave(&f2fs_stat_lock, flags); list_for_each_entry(si, &f2fs_stat_list, stat_list) { update_general_status(si->sbi); @@ -574,7 +575,7 @@ static int stat_show(struct seq_file *s, void *v) seq_printf(s, " - paged : %llu KB\n", si->page_mem >> 10); } - mutex_unlock(&f2fs_stat_mutex); + raw_spin_unlock_irqrestore(&f2fs_stat_lock, flags); return 0; } @@ -585,6 +586,7 @@ int f2fs_build_stats(struct f2fs_sb_info *sbi) { struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi); struct f2fs_stat_info *si; + unsigned long flags; int i; si = f2fs_kzalloc(sbi, sizeof(struct f2fs_stat_info), GFP_KERNEL); @@ -620,9 +622,9 @@ int f2fs_build_stats(struct f2fs_sb_info *sbi) atomic_set(&sbi->max_aw_cnt, 0); atomic_set(&sbi->max_vw_cnt, 0); - mutex_lock(&f2fs_stat_mutex); + raw_spin_lock_irqsave(&f2fs_stat_lock, flags); list_add_tail(&si->stat_list, &f2fs_stat_list); - mutex_unlock(&f2fs_stat_mutex); + raw_spin_unlock_irqrestore(&f2fs_stat_lock, flags); return 0; } @@ -630,10 +632,11 @@ int f2fs_build_stats(struct f2fs_sb_info *sbi) void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { struct f2fs_stat_info *si = F2FS_STAT(sbi); + unsigned long flags; - mutex_lock(&f2fs_stat_mutex); + raw_spin_lock_irqsave(&f2fs_stat_lock, flags); list_del(&si->stat_list); - mutex_unlock(&f2fs_stat_mutex); + raw_spin_unlock_irqrestore(&f2fs_stat_lock, flags); kfree(si); }