From: Chao Yu <yuchao0@huawei.com> To: Sahitya Tummala <stummala@codeaurora.org> Cc: Jaegeuk Kim <jaegeuk@kernel.org>, <linux-f2fs-devel@lists.sourceforge.net>, <linux-kernel@vger.kernel.org> Subject: Re: [PATCH 1/2] f2fs: Fix mount failure due to SPO after a successful online resize FS Date: Tue, 3 Mar 2020 20:06:21 +0800 [thread overview] Message-ID: <4d228adb-7038-1c03-e877-93221b920104@huawei.com> (raw) In-Reply-To: <20200302043948.GE20234@codeaurora.org> Hi Sahitya, On 2020/3/2 12:39, Sahitya Tummala wrote: > Hi Chao, > > On Fri, Feb 28, 2020 at 04:35:37PM +0800, Chao Yu wrote: >> Hi Sahitya, >> >> Good catch. >> >> On 2020/2/27 18:39, Sahitya Tummala wrote: >>> Even though online resize is successfully done, a SPO immediately >>> after resize, still causes below error in the next mount. >>> >>> [ 11.294650] F2FS-fs (sda8): Wrong user_block_count: 2233856 >>> [ 11.300272] F2FS-fs (sda8): Failed to get valid F2FS checkpoint >>> >>> This is because after FS metadata is updated in update_fs_metadata() >>> if the SBI_IS_DIRTY is not dirty, then CP will not be done to reflect >>> the new user_block_count. >>> >>> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> >>> --- >>> fs/f2fs/gc.c | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >>> index a92fa49..a14a75f 100644 >>> --- a/fs/f2fs/gc.c >>> +++ b/fs/f2fs/gc.c >>> @@ -1577,6 +1577,7 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) >>> >>> update_fs_metadata(sbi, -secs); >>> clear_sbi_flag(sbi, SBI_IS_RESIZEFS); >> >> Need a barrier here to keep order in between above code and set_sbi_flag(DIRTY)? > > I don't think a barrier will help here. Let us say there is a another context > doing CP already, then it races with update_fs_metadata(), so it may or may not > see the resize updates and it will also clear the SBI_IS_DIRTY flag set by resize > (even with a barrier). I agreed, actually, we didn't consider race condition in between CP and update_fs_metadata(), it should be fixed. > > I think we need to synchronize this with CP context, so that these resize changes > will be reflected properly. Please see the new diff below and help with the review. > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index a14a75f..5554af8 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -1467,6 +1467,7 @@ static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs) > long long user_block_count = > le64_to_cpu(F2FS_CKPT(sbi)->user_block_count); > > + clear_sbi_flag(sbi, SBI_IS_DIRTY); Why clear dirty flag here? And why not use cp_mutex to protect update_fs_metadata() in error path of f2fs_sync_fs() below? > SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs; > MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs; > FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs; > @@ -1575,9 +1576,12 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) > goto out; > } > > + mutex_lock(&sbi->cp_mutex); > update_fs_metadata(sbi, -secs); > clear_sbi_flag(sbi, SBI_IS_RESIZEFS); > set_sbi_flag(sbi, SBI_IS_DIRTY); > + mutex_unlock(&sbi->cp_mutex); > + > err = f2fs_sync_fs(sbi->sb, 1); > if (err) { > update_fs_metadata(sbi, secs); ^^^^^^^^^^^^^^ In addition, I found that we missed to use sb_lock to protect f2fs_super_block fields update, will submit a patch for that. Thanks, > > thanks, > >> >>> + set_sbi_flag(sbi, SBI_IS_DIRTY); >>> err = f2fs_sync_fs(sbi->sb, 1); >>> if (err) { >>> update_fs_metadata(sbi, secs); >> >> Do we need to add clear_sbi_flag(, SBI_IS_DIRTY) into update_fs_metadata(), so above >> path can be covered as well? >> >> Thanks, >> >>> >
WARNING: multiple messages have this Message-ID (diff)
From: Chao Yu <yuchao0@huawei.com> To: Sahitya Tummala <stummala@codeaurora.org> Cc: Jaegeuk Kim <jaegeuk@kernel.org>, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH 1/2] f2fs: Fix mount failure due to SPO after a successful online resize FS Date: Tue, 3 Mar 2020 20:06:21 +0800 [thread overview] Message-ID: <4d228adb-7038-1c03-e877-93221b920104@huawei.com> (raw) In-Reply-To: <20200302043948.GE20234@codeaurora.org> Hi Sahitya, On 2020/3/2 12:39, Sahitya Tummala wrote: > Hi Chao, > > On Fri, Feb 28, 2020 at 04:35:37PM +0800, Chao Yu wrote: >> Hi Sahitya, >> >> Good catch. >> >> On 2020/2/27 18:39, Sahitya Tummala wrote: >>> Even though online resize is successfully done, a SPO immediately >>> after resize, still causes below error in the next mount. >>> >>> [ 11.294650] F2FS-fs (sda8): Wrong user_block_count: 2233856 >>> [ 11.300272] F2FS-fs (sda8): Failed to get valid F2FS checkpoint >>> >>> This is because after FS metadata is updated in update_fs_metadata() >>> if the SBI_IS_DIRTY is not dirty, then CP will not be done to reflect >>> the new user_block_count. >>> >>> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> >>> --- >>> fs/f2fs/gc.c | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >>> index a92fa49..a14a75f 100644 >>> --- a/fs/f2fs/gc.c >>> +++ b/fs/f2fs/gc.c >>> @@ -1577,6 +1577,7 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) >>> >>> update_fs_metadata(sbi, -secs); >>> clear_sbi_flag(sbi, SBI_IS_RESIZEFS); >> >> Need a barrier here to keep order in between above code and set_sbi_flag(DIRTY)? > > I don't think a barrier will help here. Let us say there is a another context > doing CP already, then it races with update_fs_metadata(), so it may or may not > see the resize updates and it will also clear the SBI_IS_DIRTY flag set by resize > (even with a barrier). I agreed, actually, we didn't consider race condition in between CP and update_fs_metadata(), it should be fixed. > > I think we need to synchronize this with CP context, so that these resize changes > will be reflected properly. Please see the new diff below and help with the review. > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index a14a75f..5554af8 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -1467,6 +1467,7 @@ static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs) > long long user_block_count = > le64_to_cpu(F2FS_CKPT(sbi)->user_block_count); > > + clear_sbi_flag(sbi, SBI_IS_DIRTY); Why clear dirty flag here? And why not use cp_mutex to protect update_fs_metadata() in error path of f2fs_sync_fs() below? > SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs; > MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs; > FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs; > @@ -1575,9 +1576,12 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) > goto out; > } > > + mutex_lock(&sbi->cp_mutex); > update_fs_metadata(sbi, -secs); > clear_sbi_flag(sbi, SBI_IS_RESIZEFS); > set_sbi_flag(sbi, SBI_IS_DIRTY); > + mutex_unlock(&sbi->cp_mutex); > + > err = f2fs_sync_fs(sbi->sb, 1); > if (err) { > update_fs_metadata(sbi, secs); ^^^^^^^^^^^^^^ In addition, I found that we missed to use sb_lock to protect f2fs_super_block fields update, will submit a patch for that. Thanks, > > thanks, > >> >>> + set_sbi_flag(sbi, SBI_IS_DIRTY); >>> err = f2fs_sync_fs(sbi->sb, 1); >>> if (err) { >>> update_fs_metadata(sbi, secs); >> >> Do we need to add clear_sbi_flag(, SBI_IS_DIRTY) into update_fs_metadata(), so above >> path can be covered as well? >> >> Thanks, >> >>> > _______________________________________________ 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:[~2020-03-03 12:07 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-27 10:39 [PATCH 1/2] f2fs: Fix mount failure due to SPO after a successful online resize FS Sahitya Tummala 2020-02-27 10:39 ` [f2fs-dev] " Sahitya Tummala 2020-02-27 10:39 ` [PATCH 2/2] f2fs: Add a new CP flag to help fsck fix resize SPO issues Sahitya Tummala 2020-02-27 10:39 ` [f2fs-dev] " Sahitya Tummala 2020-02-28 8:35 ` [PATCH 1/2] f2fs: Fix mount failure due to SPO after a successful online resize FS Chao Yu 2020-02-28 8:35 ` [f2fs-dev] " Chao Yu 2020-03-02 4:39 ` Sahitya Tummala 2020-03-02 4:39 ` [f2fs-dev] " Sahitya Tummala 2020-03-03 12:06 ` Chao Yu [this message] 2020-03-03 12:06 ` Chao Yu 2020-03-03 14:06 ` Sahitya Tummala 2020-03-03 14:06 ` [f2fs-dev] " Sahitya Tummala
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