[PATCH V2 1/2] f2fs: Fix mount failure due to SPO after a successful online resize FS

[PATCH V2 1/2] f2fs: Fix mount failure due to SPO after a successful online resize FS

[Sahitya Tummala]

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>
---
v2:
add cp_mutex to protect update_fs_metadata()

 fs/f2fs/gc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index a92fa49..9b6640a 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1575,11 +1575,17 @@ 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) {
+		mutex_lock(&sbi->cp_mutex);
 		update_fs_metadata(sbi, secs);
+		mutex_unlock(&sbi->cp_mutex);
 		update_sb_metadata(sbi, secs);
 		f2fs_commit_super(sbi, false);
 	}
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH V2 2/2] f2fs: Add a new CP flag to help fsck fix resize SPO issues

[Sahitya Tummala]

Add and set a new CP flag CP_RESIZEFS_FLAG during
online resize FS to help fsck fix the metadata mismatch
that may happen due to SPO during resize, where SB
got updated but CP data couldn't be written yet.

fsck errors -
Info: CKPT version = 6ed7bccb
        Wrong user_block_count(2233856)
[f2fs_do_mount:3365] Checkpoint is polluted

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
---
 fs/f2fs/checkpoint.c    | 8 ++++++--
 include/linux/f2fs_fs.h | 1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index fdd7f3d..0bd4cdb 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1301,10 +1301,14 @@ static void update_ckpt_flags(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	else
 		__clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
 
-	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK) ||
-		is_sbi_flag_set(sbi, SBI_IS_RESIZEFS))
+	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
 		__set_ckpt_flags(ckpt, CP_FSCK_FLAG);
 
+	if (is_sbi_flag_set(sbi, SBI_IS_RESIZEFS))
+		__set_ckpt_flags(ckpt, CP_RESIZEFS_FLAG);
+	else
+		__clear_ckpt_flags(ckpt, CP_RESIZEFS_FLAG);
+
 	if (is_sbi_flag_set(sbi, SBI_CP_DISABLED))
 		__set_ckpt_flags(ckpt, CP_DISABLED_FLAG);
 	else
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index ac3f488..3c383dd 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -125,6 +125,7 @@ struct f2fs_super_block {
 /*
  * For checkpoint
  */
+#define CP_RESIZEFS_FLAG		0x00004000
 #define CP_DISABLED_QUICK_FLAG		0x00002000
 #define CP_DISABLED_FLAG		0x00001000
 #define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH V2 1/2] f2fs: Fix mount failure due to SPO after a successful online resize FS

[Chao Yu]

On 2020/3/3 22:29, 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>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

Re: [PATCH V2 2/2] f2fs: Add a new CP flag to help fsck fix resize SPO issues

[Chao Yu]

On 2020/3/3 22:29, Sahitya Tummala wrote:
> Add and set a new CP flag CP_RESIZEFS_FLAG during
> online resize FS to help fsck fix the metadata mismatch
> that may happen due to SPO during resize, where SB
> got updated but CP data couldn't be written yet.
> 
> fsck errors -
> Info: CKPT version = 6ed7bccb
>         Wrong user_block_count(2233856)
> [f2fs_do_mount:3365] Checkpoint is polluted

I'm not against this patch, however without this change, could
fsck have any chance to repair old image?

> 
> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Re: [PATCH V2 2/2] f2fs: Add a new CP flag to help fsck fix resize SPO issues

[Sahitya Tummala]

Hi Chao,

On Fri, Mar 06, 2020 at 09:19:39AM +0800, Chao Yu wrote:
> On 2020/3/3 22:29, Sahitya Tummala wrote:
> > Add and set a new CP flag CP_RESIZEFS_FLAG during
> > online resize FS to help fsck fix the metadata mismatch
> > that may happen due to SPO during resize, where SB
> > got updated but CP data couldn't be written yet.
> > 
> > fsck errors -
> > Info: CKPT version = 6ed7bccb
> >         Wrong user_block_count(2233856)
> > [f2fs_do_mount:3365] Checkpoint is polluted
> 
> I'm not against this patch, however without this change, could
> fsck have any chance to repair old image?

Sure, I will update the fsck patch to handle it.

thanks,
> 
> > 
> > Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
> 
> Reviewed-by: Chao Yu <yuchao0@huawei.com>

-- 
--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.