From: Chao Yu <chao@kernel.org> To: Jaegeuk Kim <jaegeuk@kernel.org> Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH v2] f2fs: avoid sb_start_intwrite during eviction Date: Wed, 2 Mar 2022 15:01:26 +0800 [thread overview] Message-ID: <3d861bf6-c404-140d-b91a-60df3ddec304@kernel.org> (raw) In-Reply-To: <Yh8EgciUTRAbWDNG@google.com> On 2022/3/2 13:45, Jaegeuk Kim wrote: > On 03/01, Jaegeuk Kim wrote: >> On 03/01, Jaegeuk Kim wrote: >>> On 03/02, Chao Yu wrote: >>>> On 2022/3/1 12:48, Jaegeuk Kim wrote: >>>>> 1. waiting for f2fs_evict_inode >>>>> [ 5560.043945] __wait_on_freeing_inode+0xac/0xf0 >>>>> [ 5560.045540] ? var_wake_function+0x30/0x30 >>>>> [ 5560.047036] find_inode_fast+0x6d/0xc0 >>>>> [ 5560.048473] iget_locked+0x79/0x230 >>>>> [ 5560.049933] f2fs_iget+0x27/0x1200 [f2fs] >>>>> [ 5560.051496] f2fs_lookup+0x18c/0x3e0 [f2fs] >>>>> [ 5560.053069] __lookup_slow+0x84/0x150 >>>>> [ 5560.054503] walk_component+0x141/0x1b0 >>>>> [ 5560.055938] link_path_walk.part.0+0x23b/0x360 >>>>> [ 5560.057541] ? end_bio_bh_io_sync+0x37/0x50 >>>>> [ 5560.059086] path_parentat+0x3c/0x90 >>>>> [ 5560.060492] filename_parentat+0xd7/0x1e0 >>>>> [ 5560.062002] ? blk_mq_free_request+0x127/0x150 >>>>> [ 5560.063576] do_renameat2+0xc1/0x5b0 >>>>> --> sb_start_write(m->mnt_sb); -> __sb_start_write(sb, SB_FREEZE_WRITE); >>>>> >>>>> [ 5560.064999] ? __check_object_size+0x13f/0x150 >>>>> [ 5560.066559] ? strncpy_from_user+0x44/0x150 >>>>> [ 5560.068038] ? getname_flags.part.0+0x4c/0x1b0 >>>>> [ 5560.069617] __x64_sys_renameat2+0x51/0x60 >>>>> >>>>> 2. waiting for sb_start_intwrite -> __sb_start_write(sb, SB_FREEZE_FS); >>>> >>>> It's still not clear that why __sb_start_write(sb, SB_FREEZE_FS) will be blocked, >>>> as SB_FREEZE_FS and SB_FREEZE_WRITE points to different locks. >>> >>> It seems I missed another call, thaw_super(), got SB_FREEZE_FS and then being >>> stuck to grab SB_FREEZE_WRITE. >> >> Ah, sorry. freeze_super(). > > Messed up. So, the lock order is SB_FREEZE_WRITE -> SB_FREEZE_FS in both cases. Yeah, I noticed this, w/ such lock order, Thread C (freeze_super) will be blocked on SB_FREEZE_WRITE, and then Thread B won't be block on SB_FREEZE_FS, right? Thanks, > >> >>> >>>> >>>> Thread A Thread B Thread C >>>> - rename >>>> - sb_start_write >>>> - __sb_start_write(SB_FREEZE_WRITE) >>>> ... >>>> - f2fs_lookup >>>> ... >>>> - __wait_on_freeing_inode >>>> - drop_slab >>>> - prune_icache_sb >>>> - inode_lru_isolate >>>> :inode->i_state |= I_FREEING >>>> - Is there any flow that it has already held >>>> SB_FREEZE_FS and try to lock SB_FREEZE_WRITE? >>>> - f2fs_evict_inode >>>> - __sb_start_write(SB_FREEZE_FS) >>>> >>>> Thanks, >>>> >>>>> >>>>> [ 5560.152447] percpu_rwsem_wait+0xaf/0x160 >>>>> [ 5560.154000] ? percpu_down_write+0xd0/0xd0 >>>>> [ 5560.155498] __percpu_down_read+0x4e/0x60 >>>>> [ 5560.157000] f2fs_evict_inode+0x5a3/0x610 [f2fs] >>>>> [ 5560.158648] ? var_wake_function+0x30/0x30 >>>>> [ 5560.160341] evict+0xd2/0x180 >>>>> [ 5560.161728] prune_icache_sb+0x81/0xb0 >>>>> --> inode_lru_isolate() -> inode->i_state |= I_FREEING; >>>>> >>>>> [ 5560.163179] super_cache_scan+0x169/0x1f0 >>>>> [ 5560.164675] do_shrink_slab+0x145/0x2b0 >>>>> [ 5560.166121] shrink_slab+0x186/0x2d0 >>>>> [ 5560.167481] drop_slab_node+0x4a/0x90 >>>>> [ 5560.168876] drop_slab+0x3e/0x80 >>>>> [ 5560.170178] drop_caches_sysctl_handler+0x75/0x90 >>>>> [ 5560.171761] proc_sys_call_handler+0x149/0x280 >>>>> [ 5560.173328] proc_sys_write+0x13/0x20 >>>>> [ 5560.174667] new_sync_write+0x117/0x1b0 >>>>> [ 5560.176120] vfs_write+0x1d5/0x270 >>>>> [ 5560.177409] ksys_write+0x67/0xe0 >>>>> >>>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> >>>>> --- >>>>> Note, I found this call stack. >>>>> >>>>> fs/f2fs/inode.c | 2 -- >>>>> 1 file changed, 2 deletions(-) >>>>> >>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >>>>> index ab8e0c06c78c..882db4bd917b 100644 >>>>> --- a/fs/f2fs/inode.c >>>>> +++ b/fs/f2fs/inode.c >>>>> @@ -778,7 +778,6 @@ void f2fs_evict_inode(struct inode *inode) >>>>> f2fs_remove_ino_entry(sbi, inode->i_ino, UPDATE_INO); >>>>> f2fs_remove_ino_entry(sbi, inode->i_ino, FLUSH_INO); >>>>> - sb_start_intwrite(inode->i_sb); >>>>> set_inode_flag(inode, FI_NO_ALLOC); >>>>> i_size_write(inode, 0); >>>>> retry: >>>>> @@ -809,7 +808,6 @@ void f2fs_evict_inode(struct inode *inode) >>>>> if (dquot_initialize_needed(inode)) >>>>> set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); >>>>> } >>>>> - sb_end_intwrite(inode->i_sb); >>>>> no_delete: >>>>> dquot_drop(inode); >>> >>> >>> _______________________________________________ >>> Linux-f2fs-devel mailing list >>> Linux-f2fs-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel >> >> >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
WARNING: multiple messages have this Message-ID (diff)
From: Chao Yu <chao@kernel.org> To: Jaegeuk Kim <jaegeuk@kernel.org> Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH v2] f2fs: avoid sb_start_intwrite during eviction Date: Wed, 2 Mar 2022 15:01:26 +0800 [thread overview] Message-ID: <3d861bf6-c404-140d-b91a-60df3ddec304@kernel.org> (raw) In-Reply-To: <Yh8EgciUTRAbWDNG@google.com> On 2022/3/2 13:45, Jaegeuk Kim wrote: > On 03/01, Jaegeuk Kim wrote: >> On 03/01, Jaegeuk Kim wrote: >>> On 03/02, Chao Yu wrote: >>>> On 2022/3/1 12:48, Jaegeuk Kim wrote: >>>>> 1. waiting for f2fs_evict_inode >>>>> [ 5560.043945] __wait_on_freeing_inode+0xac/0xf0 >>>>> [ 5560.045540] ? var_wake_function+0x30/0x30 >>>>> [ 5560.047036] find_inode_fast+0x6d/0xc0 >>>>> [ 5560.048473] iget_locked+0x79/0x230 >>>>> [ 5560.049933] f2fs_iget+0x27/0x1200 [f2fs] >>>>> [ 5560.051496] f2fs_lookup+0x18c/0x3e0 [f2fs] >>>>> [ 5560.053069] __lookup_slow+0x84/0x150 >>>>> [ 5560.054503] walk_component+0x141/0x1b0 >>>>> [ 5560.055938] link_path_walk.part.0+0x23b/0x360 >>>>> [ 5560.057541] ? end_bio_bh_io_sync+0x37/0x50 >>>>> [ 5560.059086] path_parentat+0x3c/0x90 >>>>> [ 5560.060492] filename_parentat+0xd7/0x1e0 >>>>> [ 5560.062002] ? blk_mq_free_request+0x127/0x150 >>>>> [ 5560.063576] do_renameat2+0xc1/0x5b0 >>>>> --> sb_start_write(m->mnt_sb); -> __sb_start_write(sb, SB_FREEZE_WRITE); >>>>> >>>>> [ 5560.064999] ? __check_object_size+0x13f/0x150 >>>>> [ 5560.066559] ? strncpy_from_user+0x44/0x150 >>>>> [ 5560.068038] ? getname_flags.part.0+0x4c/0x1b0 >>>>> [ 5560.069617] __x64_sys_renameat2+0x51/0x60 >>>>> >>>>> 2. waiting for sb_start_intwrite -> __sb_start_write(sb, SB_FREEZE_FS); >>>> >>>> It's still not clear that why __sb_start_write(sb, SB_FREEZE_FS) will be blocked, >>>> as SB_FREEZE_FS and SB_FREEZE_WRITE points to different locks. >>> >>> It seems I missed another call, thaw_super(), got SB_FREEZE_FS and then being >>> stuck to grab SB_FREEZE_WRITE. >> >> Ah, sorry. freeze_super(). > > Messed up. So, the lock order is SB_FREEZE_WRITE -> SB_FREEZE_FS in both cases. Yeah, I noticed this, w/ such lock order, Thread C (freeze_super) will be blocked on SB_FREEZE_WRITE, and then Thread B won't be block on SB_FREEZE_FS, right? Thanks, > >> >>> >>>> >>>> Thread A Thread B Thread C >>>> - rename >>>> - sb_start_write >>>> - __sb_start_write(SB_FREEZE_WRITE) >>>> ... >>>> - f2fs_lookup >>>> ... >>>> - __wait_on_freeing_inode >>>> - drop_slab >>>> - prune_icache_sb >>>> - inode_lru_isolate >>>> :inode->i_state |= I_FREEING >>>> - Is there any flow that it has already held >>>> SB_FREEZE_FS and try to lock SB_FREEZE_WRITE? >>>> - f2fs_evict_inode >>>> - __sb_start_write(SB_FREEZE_FS) >>>> >>>> Thanks, >>>> >>>>> >>>>> [ 5560.152447] percpu_rwsem_wait+0xaf/0x160 >>>>> [ 5560.154000] ? percpu_down_write+0xd0/0xd0 >>>>> [ 5560.155498] __percpu_down_read+0x4e/0x60 >>>>> [ 5560.157000] f2fs_evict_inode+0x5a3/0x610 [f2fs] >>>>> [ 5560.158648] ? var_wake_function+0x30/0x30 >>>>> [ 5560.160341] evict+0xd2/0x180 >>>>> [ 5560.161728] prune_icache_sb+0x81/0xb0 >>>>> --> inode_lru_isolate() -> inode->i_state |= I_FREEING; >>>>> >>>>> [ 5560.163179] super_cache_scan+0x169/0x1f0 >>>>> [ 5560.164675] do_shrink_slab+0x145/0x2b0 >>>>> [ 5560.166121] shrink_slab+0x186/0x2d0 >>>>> [ 5560.167481] drop_slab_node+0x4a/0x90 >>>>> [ 5560.168876] drop_slab+0x3e/0x80 >>>>> [ 5560.170178] drop_caches_sysctl_handler+0x75/0x90 >>>>> [ 5560.171761] proc_sys_call_handler+0x149/0x280 >>>>> [ 5560.173328] proc_sys_write+0x13/0x20 >>>>> [ 5560.174667] new_sync_write+0x117/0x1b0 >>>>> [ 5560.176120] vfs_write+0x1d5/0x270 >>>>> [ 5560.177409] ksys_write+0x67/0xe0 >>>>> >>>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> >>>>> --- >>>>> Note, I found this call stack. >>>>> >>>>> fs/f2fs/inode.c | 2 -- >>>>> 1 file changed, 2 deletions(-) >>>>> >>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >>>>> index ab8e0c06c78c..882db4bd917b 100644 >>>>> --- a/fs/f2fs/inode.c >>>>> +++ b/fs/f2fs/inode.c >>>>> @@ -778,7 +778,6 @@ void f2fs_evict_inode(struct inode *inode) >>>>> f2fs_remove_ino_entry(sbi, inode->i_ino, UPDATE_INO); >>>>> f2fs_remove_ino_entry(sbi, inode->i_ino, FLUSH_INO); >>>>> - sb_start_intwrite(inode->i_sb); >>>>> set_inode_flag(inode, FI_NO_ALLOC); >>>>> i_size_write(inode, 0); >>>>> retry: >>>>> @@ -809,7 +808,6 @@ void f2fs_evict_inode(struct inode *inode) >>>>> if (dquot_initialize_needed(inode)) >>>>> set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR); >>>>> } >>>>> - sb_end_intwrite(inode->i_sb); >>>>> no_delete: >>>>> dquot_drop(inode); >>> >>> >>> _______________________________________________ >>> Linux-f2fs-devel mailing list >>> Linux-f2fs-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel >> >> >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
next prev parent reply other threads:[~2022-03-02 7:01 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-02-15 22:00 [PATCH] f2fs: avoid sb_start_intwrite during eviction Jaegeuk Kim 2022-02-15 22:00 ` [f2fs-dev] " Jaegeuk Kim 2022-02-25 3:04 ` Chao Yu 2022-02-25 3:04 ` Chao Yu 2022-02-25 19:10 ` Jaegeuk Kim 2022-02-25 19:10 ` Jaegeuk Kim 2022-03-01 4:48 ` [f2fs-dev] [PATCH v2] " Jaegeuk Kim 2022-03-01 4:48 ` Jaegeuk Kim 2022-03-02 2:40 ` Chao Yu 2022-03-02 2:40 ` Chao Yu 2022-03-02 5:34 ` Jaegeuk Kim 2022-03-02 5:34 ` Jaegeuk Kim 2022-03-02 5:38 ` Jaegeuk Kim 2022-03-02 5:38 ` Jaegeuk Kim 2022-03-02 5:45 ` Jaegeuk Kim 2022-03-02 5:45 ` Jaegeuk Kim 2022-03-02 7:01 ` Chao Yu [this message] 2022-03-02 7:01 ` Chao Yu 2022-03-02 19:46 ` Jaegeuk Kim 2022-03-02 19:46 ` Jaegeuk Kim
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