diff mbox series

[f2fs-dev,V1] f2fs: fix potentail deadloop issue in do_recover_data

Message ID 1703502715-11936-1-git-send-email-zhiguo.niu@unisoc.com (mailing list archive)
State New
Headers show
Series [f2fs-dev,V1] f2fs: fix potentail deadloop issue in do_recover_data | expand

Commit Message

Zhiguo Niu Dec. 25, 2023, 11:11 a.m. UTC
There is a potentail deadloop issue in the corner case of
CONFIG_F2FS_FAULT_INJECTION is enabled and the return value
of f2fs_reserve_new_block is error but not -ENOSPC, such as
this error case:
if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
		return -EPERM;
besides, the mainly error -ENOSPC has been handled as bug on,
so other error cases can be proecssed normally without looping.

Fixes: 956fa1ddc132 ("f2fs: fix to check return value of f2fs_reserve_new_block()")
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
---
 fs/f2fs/recovery.c | 26 ++++++++------------------
 1 file changed, 8 insertions(+), 18 deletions(-)

Comments

Chao Yu Jan. 22, 2024, 3:46 a.m. UTC | #1
On 2023/12/25 19:11, Zhiguo Niu wrote:
> There is a potentail deadloop issue in the corner case of
> CONFIG_F2FS_FAULT_INJECTION is enabled and the return value
> of f2fs_reserve_new_block is error but not -ENOSPC, such as
> this error case:
> if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
> 		return -EPERM;

I don't see any path to trigger this error? am I missing something?

> besides, the mainly error -ENOSPC has been handled as bug on,
> so other error cases can be proecssed normally without looping.

commit 975756c41332bc5e523e9f843271ed5ab6aaaaaa
Author: Jaegeuk Kim <jaegeuk@kernel.org>
Date:   Thu May 19 11:57:21 2016 -0700

     f2fs: avoid ENOSPC fault in the recovery process

     This patch avoids impossible error injection, ENOSPC, during recovery process.

Please check above patch, I guess intention of adding such loop is
to avoid mount failure due to fault injection was triggered in
f2fs_reserve_new_block().

What about change as blew?
- keep the loop to avoid mount failure.
- remove bug_on() to avoid panic due to fault injection error.

#define DEFAULT_RETRY_COUNT		8

		for (loops = DEFAULT_RETRY_COUNT; loops > 0; loops--) {
			err = f2fs_reserve_new_block(&dn);
			if (!err ||
				!IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION))
				break;
		}

Thanks,

> 
> Fixes: 956fa1ddc132 ("f2fs: fix to check return value of f2fs_reserve_new_block()")
> Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
> ---
>   fs/f2fs/recovery.c | 26 ++++++++------------------
>   1 file changed, 8 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
> index 21381b7..5d658f6 100644
> --- a/fs/f2fs/recovery.c
> +++ b/fs/f2fs/recovery.c
> @@ -710,15 +710,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
>   		 */
>   		if (dest == NEW_ADDR) {
>   			f2fs_truncate_data_blocks_range(&dn, 1);
> -			do {
> -				err = f2fs_reserve_new_block(&dn);
> -				if (err == -ENOSPC) {
> -					f2fs_bug_on(sbi, 1);
> -					break;
> -				}
> -			} while (err &&
> -				IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
> -			if (err)
> +			err = f2fs_reserve_new_block(&dn);
> +			if (err == -ENOSPC)
> +				f2fs_bug_on(sbi, 1);
> +			else if (err)
>   				goto err;
>   			continue;
>   		}
> @@ -727,15 +722,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
>   		if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {
>   
>   			if (src == NULL_ADDR) {
> -				do {
> -					err = f2fs_reserve_new_block(&dn);
> -					if (err == -ENOSPC) {
> -						f2fs_bug_on(sbi, 1);
> -						break;
> -					}
> -				} while (err &&
> -					IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
> -				if (err)
> +				err = f2fs_reserve_new_block(&dn);
> +				if (err == -ENOSPC)
> +					f2fs_bug_on(sbi, 1);
> +				else if (err)
>   					goto err;
>   			}
>   retry_prev:
Zhiguo Niu Jan. 22, 2024, 5:46 a.m. UTC | #2
Hi Chao

On Mon, Jan 22, 2024 at 11:46 AM Chao Yu <chao@kernel.org> wrote:
>
> On 2023/12/25 19:11, Zhiguo Niu wrote:
> > There is a potentail deadloop issue in the corner case of
> > CONFIG_F2FS_FAULT_INJECTION is enabled and the return value
> > of f2fs_reserve_new_block is error but not -ENOSPC, such as
> > this error case:
> > if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
> >               return -EPERM;
>
> I don't see any path to trigger this error? am I missing something?
>
> > besides, the mainly error -ENOSPC has been handled as bug on,
> > so other error cases can be proecssed normally without looping.
>
> commit 975756c41332bc5e523e9f843271ed5ab6aaaaaa
> Author: Jaegeuk Kim <jaegeuk@kernel.org>
> Date:   Thu May 19 11:57:21 2016 -0700
>
>      f2fs: avoid ENOSPC fault in the recovery process
>
>      This patch avoids impossible error injection, ENOSPC, during recovery process.
>
> Please check above patch, I guess intention of adding such loop is
> to avoid mount failure due to fault injection was triggered in
> f2fs_reserve_new_block().
>
> What about change as blew?
> - keep the loop to avoid mount failure.
> - remove bug_on() to avoid panic due to fault injection error.
>
> #define DEFAULT_RETRY_COUNT             8
>
>                 for (loops = DEFAULT_RETRY_COUNT; loops > 0; loops--) {
>                         err = f2fs_reserve_new_block(&dn);
>                         if (!err ||
>                                 !IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION))
>                                 break;
>                 }

Thanks for your detailed explanation and I understand.
It seems that the original process is also reasonable,
so it’s okay to keep it as it is.
>
> Thanks,
>
> >
> > Fixes: 956fa1ddc132 ("f2fs: fix to check return value of f2fs_reserve_new_block()")
> > Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
> > ---
> >   fs/f2fs/recovery.c | 26 ++++++++------------------
> >   1 file changed, 8 insertions(+), 18 deletions(-)
> >
> > diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
> > index 21381b7..5d658f6 100644
> > --- a/fs/f2fs/recovery.c
> > +++ b/fs/f2fs/recovery.c
> > @@ -710,15 +710,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
> >                */
> >               if (dest == NEW_ADDR) {
> >                       f2fs_truncate_data_blocks_range(&dn, 1);
> > -                     do {
> > -                             err = f2fs_reserve_new_block(&dn);
> > -                             if (err == -ENOSPC) {
> > -                                     f2fs_bug_on(sbi, 1);
> > -                                     break;
> > -                             }
> > -                     } while (err &&
> > -                             IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
> > -                     if (err)
> > +                     err = f2fs_reserve_new_block(&dn);
> > +                     if (err == -ENOSPC)
> > +                             f2fs_bug_on(sbi, 1);
> > +                     else if (err)
> >                               goto err;
> >                       continue;
> >               }
> > @@ -727,15 +722,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
> >               if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {
> >
> >                       if (src == NULL_ADDR) {
> > -                             do {
> > -                                     err = f2fs_reserve_new_block(&dn);
> > -                                     if (err == -ENOSPC) {
> > -                                             f2fs_bug_on(sbi, 1);
> > -                                             break;
> > -                                     }
> > -                             } while (err &&
> > -                                     IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
> > -                             if (err)
> > +                             err = f2fs_reserve_new_block(&dn);
> > +                             if (err == -ENOSPC)
> > +                                     f2fs_bug_on(sbi, 1);
> > +                             else if (err)
> >                                       goto err;
> >                       }
> >   retry_prev:
Chao Yu Jan. 24, 2024, 2:54 p.m. UTC | #3
Zhiguo,

Can you please check below version? Is it fine to you?

https://lore.kernel.org/linux-f2fs-devel/20240124144915.19445-1-chao@kernel.org

On 2024/1/22 13:46, Zhiguo Niu wrote:
> Hi Chao
> 
> On Mon, Jan 22, 2024 at 11:46 AM Chao Yu <chao@kernel.org> wrote:
>>
>> On 2023/12/25 19:11, Zhiguo Niu wrote:
>>> There is a potentail deadloop issue in the corner case of
>>> CONFIG_F2FS_FAULT_INJECTION is enabled and the return value
>>> of f2fs_reserve_new_block is error but not -ENOSPC, such as
>>> this error case:
>>> if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
>>>                return -EPERM;
>>
>> I don't see any path to trigger this error? am I missing something?
>>
>>> besides, the mainly error -ENOSPC has been handled as bug on,
>>> so other error cases can be proecssed normally without looping.
>>
>> commit 975756c41332bc5e523e9f843271ed5ab6aaaaaa
>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>> Date:   Thu May 19 11:57:21 2016 -0700
>>
>>       f2fs: avoid ENOSPC fault in the recovery process
>>
>>       This patch avoids impossible error injection, ENOSPC, during recovery process.
>>
>> Please check above patch, I guess intention of adding such loop is
>> to avoid mount failure due to fault injection was triggered in
>> f2fs_reserve_new_block().
>>
>> What about change as blew?
>> - keep the loop to avoid mount failure.
>> - remove bug_on() to avoid panic due to fault injection error.
>>
>> #define DEFAULT_RETRY_COUNT             8
>>
>>                  for (loops = DEFAULT_RETRY_COUNT; loops > 0; loops--) {
>>                          err = f2fs_reserve_new_block(&dn);
>>                          if (!err ||
>>                                  !IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION))
>>                                  break;
>>                  }
> 
> Thanks for your detailed explanation and I understand.
> It seems that the original process is also reasonable,
> so it’s okay to keep it as it is.
>>
>> Thanks,
>>
>>>
>>> Fixes: 956fa1ddc132 ("f2fs: fix to check return value of f2fs_reserve_new_block()")
>>> Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
>>> ---
>>>    fs/f2fs/recovery.c | 26 ++++++++------------------
>>>    1 file changed, 8 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
>>> index 21381b7..5d658f6 100644
>>> --- a/fs/f2fs/recovery.c
>>> +++ b/fs/f2fs/recovery.c
>>> @@ -710,15 +710,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
>>>                 */
>>>                if (dest == NEW_ADDR) {
>>>                        f2fs_truncate_data_blocks_range(&dn, 1);
>>> -                     do {
>>> -                             err = f2fs_reserve_new_block(&dn);
>>> -                             if (err == -ENOSPC) {
>>> -                                     f2fs_bug_on(sbi, 1);
>>> -                                     break;
>>> -                             }
>>> -                     } while (err &&
>>> -                             IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
>>> -                     if (err)
>>> +                     err = f2fs_reserve_new_block(&dn);
>>> +                     if (err == -ENOSPC)
>>> +                             f2fs_bug_on(sbi, 1);
>>> +                     else if (err)
>>>                                goto err;
>>>                        continue;
>>>                }
>>> @@ -727,15 +722,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
>>>                if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {
>>>
>>>                        if (src == NULL_ADDR) {
>>> -                             do {
>>> -                                     err = f2fs_reserve_new_block(&dn);
>>> -                                     if (err == -ENOSPC) {
>>> -                                             f2fs_bug_on(sbi, 1);
>>> -                                             break;
>>> -                                     }
>>> -                             } while (err &&
>>> -                                     IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
>>> -                             if (err)
>>> +                             err = f2fs_reserve_new_block(&dn);
>>> +                             if (err == -ENOSPC)
>>> +                                     f2fs_bug_on(sbi, 1);
>>> +                             else if (err)
>>>                                        goto err;
>>>                        }
>>>    retry_prev:
Zhiguo Niu Jan. 25, 2024, 3:01 a.m. UTC | #4
Hi Chao,

On Wed, Jan 24, 2024 at 10:54 PM Chao Yu <chao@kernel.org> wrote:
>
> Zhiguo,
>m
> Can you please check below version? Is it fine to you?
>
> https://lore.kernel.org/linux-f2fs-devel/20240124144915.19445-1-chao@kernel.org
it is ok to me and more reasonable than my  version
thanks~
>
> On 2024/1/22 13:46, Zhiguo Niu wrote:
> > Hi Chao
> >
> > On Mon, Jan 22, 2024 at 11:46 AM Chao Yu <chao@kernel.org> wrote:
> >>
> >> On 2023/12/25 19:11, Zhiguo Niu wrote:
> >>> There is a potentail deadloop issue in the corner case of
> >>> CONFIG_F2FS_FAULT_INJECTION is enabled and the return value
> >>> of f2fs_reserve_new_block is error but not -ENOSPC, such as
> >>> this error case:
> >>> if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
> >>>                return -EPERM;
> >>
> >> I don't see any path to trigger this error? am I missing something?
> >>
> >>> besides, the mainly error -ENOSPC has been handled as bug on,
> >>> so other error cases can be proecssed normally without looping.
> >>
> >> commit 975756c41332bc5e523e9f843271ed5ab6aaaaaa
> >> Author: Jaegeuk Kim <jaegeuk@kernel.org>
> >> Date:   Thu May 19 11:57:21 2016 -0700
> >>
> >>       f2fs: avoid ENOSPC fault in the recovery process
> >>
> >>       This patch avoids impossible error injection, ENOSPC, during recovery process.
> >>
> >> Please check above patch, I guess intention of adding such loop is
> >> to avoid mount failure due to fault injection was triggered in
> >> f2fs_reserve_new_block().
> >>
> >> What about change as blew?
> >> - keep the loop to avoid mount failure.
> >> - remove bug_on() to avoid panic due to fault injection error.
> >>
> >> #define DEFAULT_RETRY_COUNT             8
> >>
> >>                  for (loops = DEFAULT_RETRY_COUNT; loops > 0; loops--) {
> >>                          err = f2fs_reserve_new_block(&dn);
> >>                          if (!err ||
> >>                                  !IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION))
> >>                                  break;
> >>                  }
> >
> > Thanks for your detailed explanation and I understand.
> > It seems that the original process is also reasonable,
> > so it’s okay to keep it as it is.
> >>
> >> Thanks,
> >>
> >>>
> >>> Fixes: 956fa1ddc132 ("f2fs: fix to check return value of f2fs_reserve_new_block()")
> >>> Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
> >>> ---
> >>>    fs/f2fs/recovery.c | 26 ++++++++------------------
> >>>    1 file changed, 8 insertions(+), 18 deletions(-)
> >>>
> >>> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
> >>> index 21381b7..5d658f6 100644
> >>> --- a/fs/f2fs/recovery.c
> >>> +++ b/fs/f2fs/recovery.c
> >>> @@ -710,15 +710,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
> >>>                 */
> >>>                if (dest == NEW_ADDR) {
> >>>                        f2fs_truncate_data_blocks_range(&dn, 1);
> >>> -                     do {
> >>> -                             err = f2fs_reserve_new_block(&dn);
> >>> -                             if (err == -ENOSPC) {
> >>> -                                     f2fs_bug_on(sbi, 1);
> >>> -                                     break;
> >>> -                             }
> >>> -                     } while (err &&
> >>> -                             IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
> >>> -                     if (err)
> >>> +                     err = f2fs_reserve_new_block(&dn);
> >>> +                     if (err == -ENOSPC)
> >>> +                             f2fs_bug_on(sbi, 1);
> >>> +                     else if (err)
> >>>                                goto err;
> >>>                        continue;
> >>>                }
> >>> @@ -727,15 +722,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
> >>>                if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {
> >>>
> >>>                        if (src == NULL_ADDR) {
> >>> -                             do {
> >>> -                                     err = f2fs_reserve_new_block(&dn);
> >>> -                                     if (err == -ENOSPC) {
> >>> -                                             f2fs_bug_on(sbi, 1);
> >>> -                                             break;
> >>> -                                     }
> >>> -                             } while (err &&
> >>> -                                     IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
> >>> -                             if (err)
> >>> +                             err = f2fs_reserve_new_block(&dn);
> >>> +                             if (err == -ENOSPC)
> >>> +                                     f2fs_bug_on(sbi, 1);
> >>> +                             else if (err)
> >>>                                        goto err;
> >>>                        }
> >>>    retry_prev:
diff mbox series

Patch

diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 21381b7..5d658f6 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -710,15 +710,10 @@  static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 		 */
 		if (dest == NEW_ADDR) {
 			f2fs_truncate_data_blocks_range(&dn, 1);
-			do {
-				err = f2fs_reserve_new_block(&dn);
-				if (err == -ENOSPC) {
-					f2fs_bug_on(sbi, 1);
-					break;
-				}
-			} while (err &&
-				IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
-			if (err)
+			err = f2fs_reserve_new_block(&dn);
+			if (err == -ENOSPC)
+				f2fs_bug_on(sbi, 1);
+			else if (err)
 				goto err;
 			continue;
 		}
@@ -727,15 +722,10 @@  static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 		if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {
 
 			if (src == NULL_ADDR) {
-				do {
-					err = f2fs_reserve_new_block(&dn);
-					if (err == -ENOSPC) {
-						f2fs_bug_on(sbi, 1);
-						break;
-					}
-				} while (err &&
-					IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
-				if (err)
+				err = f2fs_reserve_new_block(&dn);
+				if (err == -ENOSPC)
+					f2fs_bug_on(sbi, 1);
+				else if (err)
 					goto err;
 			}
 retry_prev: