Re: [PATCH v4 4/4] f2fs: stop checkpoint when get a out-of-bounds segment
From: Chao Yu
Date: Wed Feb 21 2024 - 22:51:21 EST
On 2024/2/22 10:15, Zhiguo Niu wrote:
On Thu, Feb 22, 2024 at 9:37 AM Chao Yu <chao@xxxxxxxxxx <mailto:chao@xxxxxxxxxx>> 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 <zhiguo.niu@xxxxxxxxxx <mailto:zhiguo.niu@xxxxxxxxxx>>
> ---
> 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,
> };
>