__blkdev_issue_discard() always returns 0, making the error assignment
in __submit_discard_cmd() dead code.
Initialize err to 0 and remove the error assignment from the
__blkdev_issue_discard() call to err. Move fault injection code into
already present if branch where err is set to -EIO.
This preserves the fault injection behavior while removing dead error
handling.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
---
fs/f2fs/segment.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index b45eace879d7..22b736ec9c51 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1343,15 +1343,9 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
dc->di.len += len;
+ err = 0;
if (time_to_inject(sbi, FAULT_DISCARD)) {
err = -EIO;
- } else {
- err = __blkdev_issue_discard(bdev,
- SECTOR_FROM_BLOCK(start),
- SECTOR_FROM_BLOCK(len),
- GFP_NOFS, &bio);
- }
- if (err) {
spin_lock_irqsave(&dc->lock, flags);
if (dc->state == D_PARTIAL)
dc->state = D_SUBMIT;
@@ -1360,6 +1354,8 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
break;
}
+ __blkdev_issue_discard(bdev, SECTOR_FROM_BLOCK(start),
+ SECTOR_FROM_BLOCK(len), GFP_NOFS, &bio);
f2fs_bug_on(sbi, !bio);
/*
--
2.40.0On 11/25/25 07:48, Chaitanya Kulkarni wrote:
> __blkdev_issue_discard() always returns 0, making the error assignment
> in __submit_discard_cmd() dead code.
>
> Initialize err to 0 and remove the error assignment from the
> __blkdev_issue_discard() call to err. Move fault injection code into
> already present if branch where err is set to -EIO.
>
> This preserves the fault injection behavior while removing dead error
> handling.
>
> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
> ---
> fs/f2fs/segment.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index b45eace879d7..22b736ec9c51 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1343,15 +1343,9 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
>
> dc->di.len += len;
>
> + err = 0;
> if (time_to_inject(sbi, FAULT_DISCARD)) {
> err = -EIO;
> - } else {
> - err = __blkdev_issue_discard(bdev,
> - SECTOR_FROM_BLOCK(start),
> - SECTOR_FROM_BLOCK(len),
> - GFP_NOFS, &bio);
> - }
> - if (err) {
> spin_lock_irqsave(&dc->lock, flags);
> if (dc->state == D_PARTIAL)
> dc->state = D_SUBMIT;
> @@ -1360,6 +1354,8 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
> break;
> }
>
> + __blkdev_issue_discard(bdev, SECTOR_FROM_BLOCK(start),
> + SECTOR_FROM_BLOCK(len), GFP_NOFS, &bio);
Oh, wait, bio can be NULL? Then below f2fs_bug_on() will trigger panic or warning.
Thanks,
> f2fs_bug_on(sbi, !bio);
>
> /*
On 11/25/25 18:47, Chao Yu wrote:
> On 11/25/25 07:48, Chaitanya Kulkarni wrote:
>> __blkdev_issue_discard() always returns 0, making the error assignment
>> in __submit_discard_cmd() dead code.
>>
>> Initialize err to 0 and remove the error assignment from the
>> __blkdev_issue_discard() call to err. Move fault injection code into
>> already present if branch where err is set to -EIO.
>>
>> This preserves the fault injection behavior while removing dead error
>> handling.
>>
>> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
>> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>> Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
>> ---
>> fs/f2fs/segment.c | 10 +++-------
>> 1 file changed, 3 insertions(+), 7 deletions(-)
>>
>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>> index b45eace879d7..22b736ec9c51 100644
>> --- a/fs/f2fs/segment.c
>> +++ b/fs/f2fs/segment.c
>> @@ -1343,15 +1343,9 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
>>
>> dc->di.len += len;
>>
>> + err = 0;
>> if (time_to_inject(sbi, FAULT_DISCARD)) {
>> err = -EIO;
>> - } else {
>> - err = __blkdev_issue_discard(bdev,
>> - SECTOR_FROM_BLOCK(start),
>> - SECTOR_FROM_BLOCK(len),
>> - GFP_NOFS, &bio);
>> - }
>> - if (err) {
>> spin_lock_irqsave(&dc->lock, flags);
>> if (dc->state == D_PARTIAL)
>> dc->state = D_SUBMIT;
>> @@ -1360,6 +1354,8 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
>> break;
>> }
>>
>> + __blkdev_issue_discard(bdev, SECTOR_FROM_BLOCK(start),
>> + SECTOR_FROM_BLOCK(len), GFP_NOFS, &bio);
> Oh, wait, bio can be NULL? Then below f2fs_bug_on() will trigger panic or warning.
>
> Thanks,
That will happen without this patch also or not ?
Since __blkdev_issue_discard() is always returning 0 irrespective of bio
is null or not.
The following condition in original code will only execute when err is set to
-EIO and that will only happen when time_to_inject() -> true.
Original call to __blkdev_issue_discard() without this patch will always
return 0 even for bio == NULL after __blkdev_issue_discard().
This is what we are trying to fix so caller should not rely on
__blkdev_issue_discard() return value :-
354 if (err) {
1355 spin_lock_irqsave(&dc->lock, flags);
1356 if (dc->state == D_PARTIAL)
1357 dc->state = D_SUBMIT;
1358 spin_unlock_irqrestore(&dc->lock, flags);
1359
1360 break;
1361 }
which will lead f2fs_bug_on() for bio == NULL even without this patch.
This patch is not changing exiting behavior, correct me if I'm wrong.
>
>> f2fs_bug_on(sbi, !bio);
>>
>> /*
-ck
On 11/26/25 11:37, Chaitanya Kulkarni wrote:
> On 11/25/25 18:47, Chao Yu wrote:
>> On 11/25/25 07:48, Chaitanya Kulkarni wrote:
>>> __blkdev_issue_discard() always returns 0, making the error assignment
>>> in __submit_discard_cmd() dead code.
>>>
>>> Initialize err to 0 and remove the error assignment from the
>>> __blkdev_issue_discard() call to err. Move fault injection code into
>>> already present if branch where err is set to -EIO.
>>>
>>> This preserves the fault injection behavior while removing dead error
>>> handling.
>>>
>>> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
>>> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
>>> ---
>>> fs/f2fs/segment.c | 10 +++-------
>>> 1 file changed, 3 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index b45eace879d7..22b736ec9c51 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -1343,15 +1343,9 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
>>>
>>> dc->di.len += len;
>>>
>>> + err = 0;
>>> if (time_to_inject(sbi, FAULT_DISCARD)) {
>>> err = -EIO;
>>> - } else {
>>> - err = __blkdev_issue_discard(bdev,
>>> - SECTOR_FROM_BLOCK(start),
>>> - SECTOR_FROM_BLOCK(len),
>>> - GFP_NOFS, &bio);
>>> - }
>>> - if (err) {
>>> spin_lock_irqsave(&dc->lock, flags);
>>> if (dc->state == D_PARTIAL)
>>> dc->state = D_SUBMIT;
>>> @@ -1360,6 +1354,8 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
>>> break;
>>> }
>>>
>>> + __blkdev_issue_discard(bdev, SECTOR_FROM_BLOCK(start),
>>> + SECTOR_FROM_BLOCK(len), GFP_NOFS, &bio);
>> Oh, wait, bio can be NULL? Then below f2fs_bug_on() will trigger panic or warning.
>>
>> Thanks,
>
> That will happen without this patch also or not ?
>
> Since __blkdev_issue_discard() is always returning 0 irrespective of bio
> is null or not.
>
> The following condition in original code will only execute when err is set to
> -EIO and that will only happen when time_to_inject() -> true.
> Original call to __blkdev_issue_discard() without this patch will always
> return 0 even for bio == NULL after __blkdev_issue_discard().
>
> This is what we are trying to fix so caller should not rely on
> __blkdev_issue_discard() return value :-
>
> 354 if (err) {
> 1355 spin_lock_irqsave(&dc->lock, flags);
> 1356 if (dc->state == D_PARTIAL)
> 1357 dc->state = D_SUBMIT;
> 1358 spin_unlock_irqrestore(&dc->lock, flags);
> 1359
> 1360 break;
> 1361 }
>
> which will lead f2fs_bug_on() for bio == NULL even without this patch.
>
> This patch is not changing exiting behavior, correct me if I'm wrong.
Yes, I think you're right, thanks for the explanation.
So it's fine to leave this cleanup patch as it is, and let's fix this bug in
a separated patch.
Thanks,
>
>
>>
>>> f2fs_bug_on(sbi, !bio);
>>>
>>> /*
>
> -ck
>
>
On 11/25/2025 7:48 AM, Chaitanya Kulkarni wrote: > __blkdev_issue_discard() always returns 0, making the error assignment > in __submit_discard_cmd() dead code. > > Initialize err to 0 and remove the error assignment from the > __blkdev_issue_discard() call to err. Move fault injection code into > already present if branch where err is set to -EIO. > > This preserves the fault injection behavior while removing dead error > handling. > > Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> > Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com> Reviewed-by: Chao Yu <chao@kernel.org> Thanks,
On Tue, Nov 25, 2025 at 09:10:00AM +0800, Chao Yu wrote: > Reviewed-by: Chao Yu <chao@kernel.org> Sending these all as a series might be confusing - it would be good if the individual patches get picked through the subsystem trees so that the function signature can be cleaned up after -rc1. Can we get this queued up in the f2fs tree?
On 11/25/2025 2:33 PM, Christoph Hellwig wrote: > On Tue, Nov 25, 2025 at 09:10:00AM +0800, Chao Yu wrote: >> Reviewed-by: Chao Yu <chao@kernel.org> > > Sending these all as a series might be confusing - it would be good > if the individual patches get picked through the subsystem trees > so that the function signature can be cleaned up after -rc1. > > Can we get this queued up in the f2fs tree? Yes, I think it's clean to queue this patch into f2fs tree. Thanks,
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