2024-02-20 06:12:43

by 牛志国 (Zhiguo Niu)

[permalink] [raw]
Subject: [PATCH v4 4/4] f2fs: stop checkpoint when get a out-of-bounds segment

There is low probability that an out-of-bounds segment will be got
on a small-capacity device. In order to prevent subsequent write requests
allocating block address from this invalid segment, which may cause
unexpected issue, stop checkpoint should be performed.

Also introduce a new stop cp reason: STOP_CP_REASON_NO_SEGMENT.

Signed-off-by: Zhiguo Niu <[email protected]>
---
changes of v4: use more suitable MACRO name according to Chao's suggestions
changes of v3: correct MACRO spelling and update based on the lastes code
---
---
fs/f2fs/segment.c | 7 ++++++-
include/linux/f2fs_fs.h | 1 +
2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c25aaec..e42e34c 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2665,7 +2665,12 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
if (secno >= MAIN_SECS(sbi)) {
secno = find_first_zero_bit(free_i->free_secmap,
MAIN_SECS(sbi));
- f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
+ if (secno >= MAIN_SECS(sbi)) {
+ f2fs_stop_checkpoint(sbi, false,
+ STOP_CP_REASON_NO_SEGMENT);
+ f2fs_bug_on(sbi, 1);
+ }
+
}
segno = GET_SEG_FROM_SEC(sbi, secno);
zoneno = GET_ZONE_FROM_SEC(sbi, secno);
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 9b69c50..755e9a4 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -75,6 +75,7 @@ enum stop_cp_reason {
STOP_CP_REASON_CORRUPTED_SUMMARY,
STOP_CP_REASON_UPDATE_INODE,
STOP_CP_REASON_FLUSH_FAIL,
+ STOP_CP_REASON_NO_SEGMENT,
STOP_CP_REASON_MAX,
};

--
1.9.1



2024-02-20 06:45:03

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH v4 4/4] f2fs: stop checkpoint when get a out-of-bounds segment

On 2024/2/20 14:11, Zhiguo Niu wrote:
> There is low probability that an out-of-bounds segment will be got
> on a small-capacity device. In order to prevent subsequent write requests
> allocating block address from this invalid segment, which may cause
> unexpected issue, stop checkpoint should be performed.
>
> Also introduce a new stop cp reason: STOP_CP_REASON_NO_SEGMENT.

Can you please adjust f2fs-tools as well?

>
> Signed-off-by: Zhiguo Niu <[email protected]>

Reviewed-by: Chao Yu <[email protected]>

Thanks,

2024-02-22 01:37:28

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH v4 4/4] f2fs: stop checkpoint when get a out-of-bounds segment

On 2024/2/20 14:11, Zhiguo Niu wrote:
> There is low probability that an out-of-bounds segment will be got
> on a small-capacity device. In order to prevent subsequent write requests
> allocating block address from this invalid segment, which may cause
> unexpected issue, stop checkpoint should be performed.
>
> Also introduce a new stop cp reason: STOP_CP_REASON_NO_SEGMENT.
>
> Signed-off-by: Zhiguo Niu <[email protected]>
> ---
> changes of v4: use more suitable MACRO name according to Chao's suggestions
> changes of v3: correct MACRO spelling and update based on the lastes code
> ---
> ---
> fs/f2fs/segment.c | 7 ++++++-
> include/linux/f2fs_fs.h | 1 +
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index c25aaec..e42e34c 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -2665,7 +2665,12 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> if (secno >= MAIN_SECS(sbi)) {
> secno = find_first_zero_bit(free_i->free_secmap,
> MAIN_SECS(sbi));
> - f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> + if (secno >= MAIN_SECS(sbi)) {
> + f2fs_stop_checkpoint(sbi, false,
> + STOP_CP_REASON_NO_SEGMENT);

We should relocate stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT) outside
segmap_lock spinlock, due to it may sleep in f2fs_flush_merged_writes().

Thanks,

> + f2fs_bug_on(sbi, 1);
> + }
> +
> }
> segno = GET_SEG_FROM_SEC(sbi, secno);
> zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> index 9b69c50..755e9a4 100644
> --- a/include/linux/f2fs_fs.h
> +++ b/include/linux/f2fs_fs.h
> @@ -75,6 +75,7 @@ enum stop_cp_reason {
> STOP_CP_REASON_CORRUPTED_SUMMARY,
> STOP_CP_REASON_UPDATE_INODE,
> STOP_CP_REASON_FLUSH_FAIL,
> + STOP_CP_REASON_NO_SEGMENT,
> STOP_CP_REASON_MAX,
> };
>

2024-02-22 03:51:20

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH v4 4/4] f2fs: stop checkpoint when get a out-of-bounds segment

On 2024/2/22 10:15, Zhiguo Niu wrote:
>
>
> On Thu, Feb 22, 2024 at 9:37 AM Chao Yu <[email protected] <mailto:[email protected]>> wrote:
>
> On 2024/2/20 14:11, Zhiguo Niu wrote:
> > There is low probability that an out-of-bounds segment will be got
> > on a small-capacity device. In order to prevent subsequent write requests
> > allocating block address from this invalid segment, which may cause
> > unexpected issue, stop checkpoint should be performed.
> >
> > Also introduce a new stop cp reason: STOP_CP_REASON_NO_SEGMENT.
> >
> > Signed-off-by: Zhiguo Niu <[email protected] <mailto:[email protected]>>
> > ---
> > changes of v4: use more suitable MACRO name according to Chao's suggestions
> > changes of v3: correct MACRO spelling and update based on the lastes code
> > ---
> > ---
> >   fs/f2fs/segment.c       | 7 ++++++-
> >   include/linux/f2fs_fs.h | 1 +
> >   2 files changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index c25aaec..e42e34c 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -2665,7 +2665,12 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >       if (secno >= MAIN_SECS(sbi)) {
> >               secno = find_first_zero_bit(free_i->free_secmap,
> >                                                       MAIN_SECS(sbi));
> > -             f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> > +             if (secno >= MAIN_SECS(sbi)) {
> > +                     f2fs_stop_checkpoint(sbi, false,
> > +                             STOP_CP_REASON_NO_SEGMENT);
>
> We should relocate stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT) outside
> segmap_lock spinlock, due to it may sleep in f2fs_flush_merged_writes().
>
> Indeed it is. How about the following fix?
> @@ -2665,11 +2665,7 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>         if (secno >= MAIN_SECS(sbi)) {
>                 secno = find_first_zero_bit(free_i->free_secmap,
>                                                         MAIN_SECS(sbi));
> -               if (secno >= MAIN_SECS(sbi)) {
> -                       f2fs_stop_checkpoint(sbi, false,
> -                               STOP_CP_REASON_NO_SEGMENT);
> -                       f2fs_bug_on(sbi, 1);
> -               }
> +               f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
>         }
>         segno = GET_SEG_FROM_SEC(sbi, secno);
>         zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> @@ -2700,6 +2696,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>         __set_inuse(sbi, segno);
>         *newseg = segno;
>         spin_unlock(&free_i->segmap_lock);
> +       if (secno >= MAIN_SECS(sbi))
> +               f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);

How about this?

---
fs/f2fs/segment.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index d0209ea77dd2..8edc42071e6f 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2646,6 +2646,7 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
bool init = true;
int i;
+ int ret = 0;

spin_lock(&free_i->segmap_lock);

@@ -2671,9 +2672,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
secno = find_first_zero_bit(free_i->free_secmap,
MAIN_SECS(sbi));
if (secno >= MAIN_SECS(sbi)) {
- f2fs_stop_checkpoint(sbi, false,
- STOP_CP_REASON_NO_SEGMENT);
- f2fs_bug_on(sbi, 1);
+ ret = -ENOSPC;
+ goto out_unlock;
}
}
segno = GET_SEG_FROM_SEC(sbi, secno);
@@ -2704,7 +2704,13 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
__set_inuse(sbi, segno);
*newseg = segno;
+out_unlock:
spin_unlock(&free_i->segmap_lock);
+
+ if (ret) {
+ f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
+ f2fs_bug_on(sbi, 1);
+ }
}

static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
--
2.40.1

>
> Thanks,
>
> > +                     f2fs_bug_on(sbi, 1);
> > +             }
> > +
> >       }
> >       segno = GET_SEG_FROM_SEC(sbi, secno);
> >       zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> > index 9b69c50..755e9a4 100644
> > --- a/include/linux/f2fs_fs.h
> > +++ b/include/linux/f2fs_fs.h
> > @@ -75,6 +75,7 @@ enum stop_cp_reason {
> >       STOP_CP_REASON_CORRUPTED_SUMMARY,
> >       STOP_CP_REASON_UPDATE_INODE,
> >       STOP_CP_REASON_FLUSH_FAIL,
> > +     STOP_CP_REASON_NO_SEGMENT,
> >       STOP_CP_REASON_MAX,
> >   };
> >
>

2024-02-22 06:12:39

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH v4 4/4] f2fs: stop checkpoint when get a out-of-bounds segment

On 2024/2/22 13:48, Zhiguo Niu wrote:
> Dear Chao,
>
> On Thu, Feb 22, 2024 at 11:51 AM Chao Yu <[email protected] <mailto:[email protected]>> wrote:
>
> On 2024/2/22 10:15, Zhiguo Niu wrote:
> >
> >
> > On Thu, Feb 22, 2024 at 9:37 AM Chao Yu <[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>>> wrote:
> >
> >     On 2024/2/20 14:11, Zhiguo Niu wrote:
> >      > There is low probability that an out-of-bounds segment will be got
> >      > on a small-capacity device. In order to prevent subsequent write requests
> >      > allocating block address from this invalid segment, which may cause
> >      > unexpected issue, stop checkpoint should be performed.
> >      >
> >      > Also introduce a new stop cp reason: STOP_CP_REASON_NO_SEGMENT.
> >      >
> >      > Signed-off-by: Zhiguo Niu <[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>>>
> >      > ---
> >      > changes of v4: use more suitable MACRO name according to Chao's suggestions
> >      > changes of v3: correct MACRO spelling and update based on the lastes code
> >      > ---
> >      > ---
> >      >   fs/f2fs/segment.c       | 7 ++++++-
> >      >   include/linux/f2fs_fs.h | 1 +
> >      >   2 files changed, 7 insertions(+), 1 deletion(-)
> >      >
> >      > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> >      > index c25aaec..e42e34c 100644
> >      > --- a/fs/f2fs/segment.c
> >      > +++ b/fs/f2fs/segment.c
> >      > @@ -2665,7 +2665,12 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >      >       if (secno >= MAIN_SECS(sbi)) {
> >      >               secno = find_first_zero_bit(free_i->free_secmap,
> >      >                                                       MAIN_SECS(sbi));
> >      > -             f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> >      > +             if (secno >= MAIN_SECS(sbi)) {
> >      > +                     f2fs_stop_checkpoint(sbi, false,
> >      > +                             STOP_CP_REASON_NO_SEGMENT);
> >
> >     We should relocate stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT) outside
> >     segmap_lock spinlock, due to it may sleep in f2fs_flush_merged_writes().
> >
> > Indeed it is. How about the following fix?
> > @@ -2665,11 +2665,7 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >          if (secno >= MAIN_SECS(sbi)) {
> >                  secno = find_first_zero_bit(free_i->free_secmap,
> >                                                          MAIN_SECS(sbi));
> > -               if (secno >= MAIN_SECS(sbi)) {
> > -                       f2fs_stop_checkpoint(sbi, false,
> > -                               STOP_CP_REASON_NO_SEGMENT);
> > -                       f2fs_bug_on(sbi, 1);
> > -               }
> > +               f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> >          }
> >          segno = GET_SEG_FROM_SEC(sbi, secno);
> >          zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> > @@ -2700,6 +2696,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >          __set_inuse(sbi, segno);
> >          *newseg = segno;
> >          spin_unlock(&free_i->segmap_lock);
> > +       if (secno >= MAIN_SECS(sbi))
> > +               f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
>
> How about this?
>
> ---
>   fs/f2fs/segment.c | 12 +++++++++---
>   1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index d0209ea77dd2..8edc42071e6f 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -2646,6 +2646,7 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>         unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
>         bool init = true;
>         int i;
> +       int ret = 0;
>
>         spin_lock(&free_i->segmap_lock);
>
> @@ -2671,9 +2672,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>                 secno = find_first_zero_bit(free_i->free_secmap,
>                                                         MAIN_SECS(sbi));
>                 if (secno >= MAIN_SECS(sbi)) {
> -                       f2fs_stop_checkpoint(sbi, false,
> -                               STOP_CP_REASON_NO_SEGMENT);
> -                       f2fs_bug_on(sbi, 1);
> +                       ret = -ENOSPC;
> +                       goto out_unlock;
>
>                 }
>         }
>         segno = GET_SEG_FROM_SEC(sbi, secno);
> @@ -2704,7 +2704,13 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>         f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
>         __set_inuse(sbi, segno);
>         *newseg = segno;
> +out_unlock:
>         spin_unlock(&free_i->segmap_lock);
> +
> +       if (ret) {
> +               f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
> +               f2fs_bug_on(sbi, 1);
>
> *newseg will not be changed , its caller new_curseg will set a segno got from __get_next_segno to
> curseg->segno, this segno maybe 0, this won't cause any problems because cp has stopped, right?
> thanks!

Since there is no free segment, no matter which segno we assign,
there should be problem, so I'd like to fix to hanlde such error
in caller corectly, unluckly, I doesn't covered all cases yet.

From b2155a30827bf017d0b3daa1549774aba5953b7e Mon Sep 17 00:00:00 2001
From: Chao Yu <[email protected]>
Date: Mon, 19 Feb 2024 15:15:30 +0800
Subject: f2fs: fix to handle segment allocation failure correctly

Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/data.c | 7 +++++--
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/gc.c | 7 ++++++-
fs/f2fs/segment.c | 46 +++++++++++++++++++++++++++++++++++++++-------
4 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 0c9aa3082fcf..c21b92f18463 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1416,8 +1416,11 @@ static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)

set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
old_blkaddr = dn->data_blkaddr;
- f2fs_allocate_data_block(sbi, NULL, old_blkaddr, &dn->data_blkaddr,
- &sum, seg_type, NULL);
+ err = f2fs_allocate_data_block(sbi, NULL, old_blkaddr,
+ &dn->data_blkaddr, &sum, seg_type, NULL);
+ if (err)
+ return err;
+
if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
f2fs_invalidate_internal_cache(sbi, old_blkaddr);

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index b951575bc341..075a8378585d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3733,7 +3733,7 @@ void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
block_t old_addr, block_t new_addr,
unsigned char version, bool recover_curseg,
bool recover_newaddr);
-void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
+int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
block_t old_blkaddr, block_t *new_blkaddr,
struct f2fs_summary *sum, int type,
struct f2fs_io_info *fio);
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 6d160d50e14e..42e75e9b8b6b 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1358,8 +1358,13 @@ static int move_data_block(struct inode *inode, block_t bidx,
set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);

/* allocate block address */
- f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
+ err = f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
&sum, type, NULL);
+ if (err) {
+ f2fs_put_page(mpage, 1);
+ /* filesystem should shutdown, no need to recovery block */
+ goto up_out;
+ }

fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 8edc42071e6f..d02e92034ae3 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2636,7 +2636,7 @@ static int is_next_segment_free(struct f2fs_sb_info *sbi,
* Find a new segment from the free segments bitmap to right order
* This function should be returned with success, otherwise BUG
*/
-static void get_new_segment(struct f2fs_sb_info *sbi,
+static int get_new_segment(struct f2fs_sb_info *sbi,
unsigned int *newseg, bool new_sec, bool pinning)
{
struct free_segmap_info *free_i = FREE_I(sbi);
@@ -2650,6 +2650,11 @@ static void get_new_segment(struct f2fs_sb_info *sbi,

spin_lock(&free_i->segmap_lock);

+ if (time_to_inject(sbi, FAULT_NO_SEGMENT)) {
+ ret = -ENOSPC;
+ goto out_unlock;
+ }
+
if (!new_sec && ((*newseg + 1) % SEGS_PER_SEC(sbi))) {
segno = find_next_zero_bit(free_i->free_segmap,
GET_SEG_FROM_SEC(sbi, hint + 1), *newseg + 1);
@@ -2711,6 +2716,7 @@ out_unlock:
f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
f2fs_bug_on(sbi, 1);
}
+ return ret;
}

static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
@@ -2719,6 +2725,10 @@ static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
struct summary_footer *sum_footer;
unsigned short seg_type = curseg->seg_type;

+ /* only happen when get_new_segment() fails */
+ if (curseg->next_segno == NULL_SEGNO)
+ return;
+
curseg->inited = true;
curseg->segno = curseg->next_segno;
curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno);
@@ -2783,7 +2793,10 @@ static int new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
write_sum_page(sbi, curseg->sum_blk, GET_SUM_BLOCK(sbi, segno));

segno = __get_next_segno(sbi, type);
- get_new_segment(sbi, &segno, new_sec, pinning);
+ if (get_new_segment(sbi, &segno, new_sec, pinning)) {
+ curseg->segno = NULL_SEGNO;
+ return -ENOSPC;
+ }
if (new_sec && pinning &&
!f2fs_valid_pinned_area(sbi, START_BLOCK(sbi, segno))) {
__set_free(sbi, segno);
@@ -3425,7 +3438,7 @@ static void f2fs_randomize_chunk(struct f2fs_sb_info *sbi,
get_random_u32_inclusive(1, sbi->max_fragment_hole);
}

-void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
+int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
block_t old_blkaddr, block_t *new_blkaddr,
struct f2fs_summary *sum, int type,
struct f2fs_io_info *fio)
@@ -3442,6 +3455,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
mutex_lock(&curseg->curseg_mutex);
down_write(&sit_i->sentry_lock);

+ if (curseg->segno == NULL_SEGNO)
+ goto out_err;
+
if (from_gc) {
f2fs_bug_on(sbi, GET_SEGNO(sbi, old_blkaddr) == NULL_SEGNO);
se = get_seg_entry(sbi, GET_SEGNO(sbi, old_blkaddr));
@@ -3500,6 +3516,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
change_curseg(sbi, type);
stat_inc_seg_type(sbi, curseg);
}
+
+ if (curseg->segno == NULL_SEGNO)
+ goto out_err;
}

skip_new_segment:
@@ -3534,8 +3553,15 @@ skip_new_segment:
}

mutex_unlock(&curseg->curseg_mutex);
-
f2fs_up_read(&SM_I(sbi)->curseg_lock);
+ return 0;
+out_err:
+ *new_blkaddr = NULL_ADDR;
+ up_write(&sit_i->sentry_lock);
+ mutex_unlock(&curseg->curseg_mutex);
+ f2fs_up_read(&SM_I(sbi)->curseg_lock);
+ return -ENOSPC;
+
}

void f2fs_update_device_state(struct f2fs_sb_info *sbi, nid_t ino,
@@ -3573,8 +3599,14 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
if (keep_order)
f2fs_down_read(&fio->sbi->io_order_lock);

- f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
- &fio->new_blkaddr, sum, type, fio);
+ if (f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
+ &fio->new_blkaddr, sum, type, fio)) {
+ if (fscrypt_inode_uses_fs_layer_crypto(fio->page->mapping->host))
+ fscrypt_finalize_bounce_page(&fio->encrypted_page);
+ if (PageWriteback(fio->page))
+ end_page_writeback(fio->page);
+ goto out;
+ }
if (GET_SEGNO(fio->sbi, fio->old_blkaddr) != NULL_SEGNO)
f2fs_invalidate_internal_cache(fio->sbi, fio->old_blkaddr);

@@ -3582,7 +3614,7 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
f2fs_submit_page_write(fio);

f2fs_update_device_state(fio->sbi, fio->ino, fio->new_blkaddr, 1);
-
+out:
if (keep_order)
f2fs_up_read(&fio->sbi->io_order_lock);
}
--
cgit v1.2.3-18-g5258

>
> +       }
>   }
>
>   static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
> --
> 2.40.1
>
> >
> >     Thanks,
> >
> >      > +                     f2fs_bug_on(sbi, 1);
> >      > +             }
> >      > +
> >      >       }
> >      >       segno = GET_SEG_FROM_SEC(sbi, secno);
> >      >       zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> >      > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> >      > index 9b69c50..755e9a4 100644
> >      > --- a/include/linux/f2fs_fs.h
> >      > +++ b/include/linux/f2fs_fs.h
> >      > @@ -75,6 +75,7 @@ enum stop_cp_reason {
> >      >       STOP_CP_REASON_CORRUPTED_SUMMARY,
> >      >       STOP_CP_REASON_UPDATE_INODE,
> >      >       STOP_CP_REASON_FLUSH_FAIL,
> >      > +     STOP_CP_REASON_NO_SEGMENT,
> >      >       STOP_CP_REASON_MAX,
> >      >   };
> >      >
> >
>

2024-02-22 12:13:03

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH v4 4/4] f2fs: stop checkpoint when get a out-of-bounds segment

On 2024/2/22 15:15, Zhiguo Niu wrote:
>
>
> On Thu, Feb 22, 2024 at 2:12 PM Chao Yu <[email protected] <mailto:[email protected]>> wrote:
>
> On 2024/2/22 13:48, Zhiguo Niu wrote:
> > Dear Chao,
> >
> > On Thu, Feb 22, 2024 at 11:51 AM Chao Yu <[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>>> wrote:
> >
> >     On 2024/2/22 10:15, Zhiguo Niu wrote:
> >      >
> >      >
> >      > On Thu, Feb 22, 2024 at 9:37 AM Chao Yu <[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>> <mailto:[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>>>> wrote:
> >      >
> >      >     On 2024/2/20 14:11, Zhiguo Niu wrote:
> >      >      > There is low probability that an out-of-bounds segment will be got
> >      >      > on a small-capacity device. In order to prevent subsequent write requests
> >      >      > allocating block address from this invalid segment, which may cause
> >      >      > unexpected issue, stop checkpoint should be performed.
> >      >      >
> >      >      > Also introduce a new stop cp reason: STOP_CP_REASON_NO_SEGMENT.
> >      >      >
> >      >      > Signed-off-by: Zhiguo Niu <[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>> <mailto:[email protected] <mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>>>>
> >      >      > ---
> >      >      > changes of v4: use more suitable MACRO name according to Chao's suggestions
> >      >      > changes of v3: correct MACRO spelling and update based on the lastes code
> >      >      > ---
> >      >      > ---
> >      >      >   fs/f2fs/segment.c       | 7 ++++++-
> >      >      >   include/linux/f2fs_fs.h | 1 +
> >      >      >   2 files changed, 7 insertions(+), 1 deletion(-)
> >      >      >
> >      >      > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> >      >      > index c25aaec..e42e34c 100644
> >      >      > --- a/fs/f2fs/segment.c
> >      >      > +++ b/fs/f2fs/segment.c
> >      >      > @@ -2665,7 +2665,12 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >      >      >       if (secno >= MAIN_SECS(sbi)) {
> >      >      >               secno = find_first_zero_bit(free_i->free_secmap,
> >      >      >                                                       MAIN_SECS(sbi));
> >      >      > -             f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> >      >      > +             if (secno >= MAIN_SECS(sbi)) {
> >      >      > +                     f2fs_stop_checkpoint(sbi, false,
> >      >      > +                             STOP_CP_REASON_NO_SEGMENT);
> >      >
> >      >     We should relocate stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT) outside
> >      >     segmap_lock spinlock, due to it may sleep in f2fs_flush_merged_writes().
> >      >
> >      > Indeed it is. How about the following fix?
> >      > @@ -2665,11 +2665,7 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >      >          if (secno >= MAIN_SECS(sbi)) {
> >      >                  secno = find_first_zero_bit(free_i->free_secmap,
> >      >                                                          MAIN_SECS(sbi));
> >      > -               if (secno >= MAIN_SECS(sbi)) {
> >      > -                       f2fs_stop_checkpoint(sbi, false,
> >      > -                               STOP_CP_REASON_NO_SEGMENT);
> >      > -                       f2fs_bug_on(sbi, 1);
> >      > -               }
> >      > +               f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> >      >          }
> >      >          segno = GET_SEG_FROM_SEC(sbi, secno);
> >      >          zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> >      > @@ -2700,6 +2696,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >      >          __set_inuse(sbi, segno);
> >      >          *newseg = segno;
> >      >          spin_unlock(&free_i->segmap_lock);
> >      > +       if (secno >= MAIN_SECS(sbi))
> >      > +               f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
> >
> >     How about this?
> >
> >     ---
> >        fs/f2fs/segment.c | 12 +++++++++---
> >        1 file changed, 9 insertions(+), 3 deletions(-)
> >
> >     diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> >     index d0209ea77dd2..8edc42071e6f 100644
> >     --- a/fs/f2fs/segment.c
> >     +++ b/fs/f2fs/segment.c
> >     @@ -2646,6 +2646,7 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >              unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
> >              bool init = true;
> >              int i;
> >     +       int ret = 0;
> >
> >              spin_lock(&free_i->segmap_lock);
> >
> >     @@ -2671,9 +2672,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >                      secno = find_first_zero_bit(free_i->free_secmap,
> >                                                              MAIN_SECS(sbi));
> >                      if (secno >= MAIN_SECS(sbi)) {
> >     -                       f2fs_stop_checkpoint(sbi, false,
> >     -                               STOP_CP_REASON_NO_SEGMENT);
> >     -                       f2fs_bug_on(sbi, 1);
> >     +                       ret = -ENOSPC;
> >     +                       goto out_unlock;
> >
> >                      }
> >              }
> >              segno = GET_SEG_FROM_SEC(sbi, secno);
> >     @@ -2704,7 +2704,13 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> >              f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
> >              __set_inuse(sbi, segno);
> >              *newseg = segno;
> >     +out_unlock:
> >              spin_unlock(&free_i->segmap_lock);
> >     +
> >     +       if (ret) {
> >     +               f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
> >     +               f2fs_bug_on(sbi, 1);
> >
> > *newseg will not be changed , its caller new_curseg will set a segno got from __get_next_segno to
> > curseg->segno, this segno maybe 0, this won't cause any problems because cp has stopped, right?
> > thanks!
>
> Since there is no free segment, no matter which segno we assign,
>
> OK,  Shall I update this patch first ?

I can send a separated patch, and it can be merged to first one
if Jaegeuk want to.

Thanks,

>
> there should be problem, so I'd like to fix to hanlde such error
> in caller corectly, unluckly, I doesn't covered all cases yet.
>
>  From b2155a30827bf017d0b3daa1549774aba5953b7e Mon Sep 17 00:00:00 2001
> From: Chao Yu <[email protected] <mailto:[email protected]>>
> Date: Mon, 19 Feb 2024 15:15:30 +0800
> Subject: f2fs: fix to handle segment allocation failure correctly
>
> I think check allocate results is indeed more reasonable.
>
> Signed-off-by: Chao Yu <[email protected] <mailto:[email protected]>>
> ---
>   fs/f2fs/data.c    |  7 +++++--
>   fs/f2fs/f2fs.h    |  2 +-
>   fs/f2fs/gc.c      |  7 ++++++-
>   fs/f2fs/segment.c | 46 +++++++++++++++++++++++++++++++++++++++-------
>   4 files changed, 51 insertions(+), 11 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 0c9aa3082fcf..c21b92f18463 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1416,8 +1416,11 @@ static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)
>
>         set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
>         old_blkaddr = dn->data_blkaddr;
> -       f2fs_allocate_data_block(sbi, NULL, old_blkaddr, &dn->data_blkaddr,
> -                               &sum, seg_type, NULL);
> +       err = f2fs_allocate_data_block(sbi, NULL, old_blkaddr,
> +                               &dn->data_blkaddr, &sum, seg_type, NULL);
> +       if (err)
> +               return err;
> +
>         if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
>                 f2fs_invalidate_internal_cache(sbi, old_blkaddr);
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index b951575bc341..075a8378585d 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -3733,7 +3733,7 @@ void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
>                         block_t old_addr, block_t new_addr,
>                         unsigned char version, bool recover_curseg,
>                         bool recover_newaddr);
> -void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
> +int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
>                         block_t old_blkaddr, block_t *new_blkaddr,
>                         struct f2fs_summary *sum, int type,
>                         struct f2fs_io_info *fio);
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 6d160d50e14e..42e75e9b8b6b 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -1358,8 +1358,13 @@ static int move_data_block(struct inode *inode, block_t bidx,
>         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
>
>         /* allocate block address */
> -       f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
> +       err = f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
>                                 &sum, type, NULL);
> +       if (err) {
> +               f2fs_put_page(mpage, 1);
> +               /* filesystem should shutdown, no need to recovery block */
> +               goto up_out;
> +       }
>
>         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
>                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 8edc42071e6f..d02e92034ae3 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -2636,7 +2636,7 @@ static int is_next_segment_free(struct f2fs_sb_info *sbi,
>    * Find a new segment from the free segments bitmap to right order
>    * This function should be returned with success, otherwise BUG
>    */
> -static void get_new_segment(struct f2fs_sb_info *sbi,
> +static int get_new_segment(struct f2fs_sb_info *sbi,
>                         unsigned int *newseg, bool new_sec, bool pinning)
>   {
>         struct free_segmap_info *free_i = FREE_I(sbi);
> @@ -2650,6 +2650,11 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>
>         spin_lock(&free_i->segmap_lock);
>
> +       if (time_to_inject(sbi, FAULT_NO_SEGMENT)) {
> +               ret = -ENOSPC;
> +               goto out_unlock;
> +       }
> +
>         if (!new_sec && ((*newseg + 1) % SEGS_PER_SEC(sbi))) {
>                 segno = find_next_zero_bit(free_i->free_segmap,
>                         GET_SEG_FROM_SEC(sbi, hint + 1), *newseg + 1);
> @@ -2711,6 +2716,7 @@ out_unlock:
>                 f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
>                 f2fs_bug_on(sbi, 1);
>         }
> +       return ret;
>   }
>
>   static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
> @@ -2719,6 +2725,10 @@ static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
>         struct summary_footer *sum_footer;
>         unsigned short seg_type = curseg->seg_type;
>
> +       /* only happen when get_new_segment() fails */
> +       if (curseg->next_segno == NULL_SEGNO)
> +               return;
> +
>         curseg->inited = true;
>         curseg->segno = curseg->next_segno;
>         curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno);
> @@ -2783,7 +2793,10 @@ static int new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
>                 write_sum_page(sbi, curseg->sum_blk, GET_SUM_BLOCK(sbi, segno));
>
>         segno = __get_next_segno(sbi, type);
> -       get_new_segment(sbi, &segno, new_sec, pinning);
> +       if (get_new_segment(sbi, &segno, new_sec, pinning)) {
> +               curseg->segno = NULL_SEGNO;
> +               return -ENOSPC;
> +       }
>         if (new_sec && pinning &&
>             !f2fs_valid_pinned_area(sbi, START_BLOCK(sbi, segno))) {
>                 __set_free(sbi, segno);
> @@ -3425,7 +3438,7 @@ static void f2fs_randomize_chunk(struct f2fs_sb_info *sbi,
>                 get_random_u32_inclusive(1, sbi->max_fragment_hole);
>   }
>
> -void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
> +int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
>                 block_t old_blkaddr, block_t *new_blkaddr,
>                 struct f2fs_summary *sum, int type,
>                 struct f2fs_io_info *fio)
> @@ -3442,6 +3455,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
>         mutex_lock(&curseg->curseg_mutex);
>         down_write(&sit_i->sentry_lock);
>
> +       if (curseg->segno == NULL_SEGNO)
> +               goto out_err;
> +
>         if (from_gc) {
>                 f2fs_bug_on(sbi, GET_SEGNO(sbi, old_blkaddr) == NULL_SEGNO);
>                 se = get_seg_entry(sbi, GET_SEGNO(sbi, old_blkaddr));
> @@ -3500,6 +3516,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
>                                 change_curseg(sbi, type);
>                         stat_inc_seg_type(sbi, curseg);
>                 }
> +
> +               if (curseg->segno == NULL_SEGNO)
> +                       goto out_err;
>         }
>
>   skip_new_segment:
> @@ -3534,8 +3553,15 @@ skip_new_segment:
>         }
>
>         mutex_unlock(&curseg->curseg_mutex);
> -
>         f2fs_up_read(&SM_I(sbi)->curseg_lock);
> +       return 0;
> +out_err:
> +       *new_blkaddr = NULL_ADDR;
> +       up_write(&sit_i->sentry_lock);
> +       mutex_unlock(&curseg->curseg_mutex);
> +       f2fs_up_read(&SM_I(sbi)->curseg_lock);
> +       return -ENOSPC;
> +
>   }
>
>   void f2fs_update_device_state(struct f2fs_sb_info *sbi, nid_t ino,
> @@ -3573,8 +3599,14 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
>         if (keep_order)
>                 f2fs_down_read(&fio->sbi->io_order_lock);
>
> -       f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
> -                       &fio->new_blkaddr, sum, type, fio);
> +       if (f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
> +                       &fio->new_blkaddr, sum, type, fio)) {
> +               if (fscrypt_inode_uses_fs_layer_crypto(fio->page->mapping->host))
> +                       fscrypt_finalize_bounce_page(&fio->encrypted_page);
> +               if (PageWriteback(fio->page))
> +                       end_page_writeback(fio->page);
> +               goto out;
> +       }
>         if (GET_SEGNO(fio->sbi, fio->old_blkaddr) != NULL_SEGNO)
>                 f2fs_invalidate_internal_cache(fio->sbi, fio->old_blkaddr);
>
> @@ -3582,7 +3614,7 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
>         f2fs_submit_page_write(fio);
>
>         f2fs_update_device_state(fio->sbi, fio->ino, fio->new_blkaddr, 1);
> -
> +out:
>         if (keep_order)
>                 f2fs_up_read(&fio->sbi->io_order_lock);
>   }
> --
> cgit v1.2.3-18-g5258
>
> >
> >     +       }
> >        }
> >
> >        static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
> >     --
> >     2.40.1
> >
> >      >
> >      >     Thanks,
> >      >
> >      >      > +                     f2fs_bug_on(sbi, 1);
> >      >      > +             }
> >      >      > +
> >      >      >       }
> >      >      >       segno = GET_SEG_FROM_SEC(sbi, secno);
> >      >      >       zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> >      >      > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> >      >      > index 9b69c50..755e9a4 100644
> >      >      > --- a/include/linux/f2fs_fs.h
> >      >      > +++ b/include/linux/f2fs_fs.h
> >      >      > @@ -75,6 +75,7 @@ enum stop_cp_reason {
> >      >      >       STOP_CP_REASON_CORRUPTED_SUMMARY,
> >      >      >       STOP_CP_REASON_UPDATE_INODE,
> >      >      >       STOP_CP_REASON_FLUSH_FAIL,
> >      >      > +     STOP_CP_REASON_NO_SEGMENT,
> >      >      >       STOP_CP_REASON_MAX,
> >      >      >   };
> >      >      >
> >      >
> >
>