Subject: [PATCH] ocfs2: ratelimit the 'max lookup times reached' notice

Running stress-ng on ocfs2 completely fills the kernel log with
'max lookup times reached, filesystem may have nested directories.'

Let's ratelimit this message as done with others in the code.

Test-case:

# mkfs.ocfs2 --mount local $DEV
# mount $DEV $MNT
# cd $MNT

# dmesg -C
# stress-ng --dirdeep 1 --dirdeep-ops 1000
# dmesg | grep -c 'max lookup times reached'

Before:

# dmesg -C
# stress-ng --dirdeep 1 --dirdeep-ops 1000
...
stress-ng: info: [11116] successful run completed in 3.03s

# dmesg | grep -c 'max lookup times reached'
967

After:

# dmesg -C
# stress-ng --dirdeep 1 --dirdeep-ops 1000
...
stress-ng: info: [739] successful run completed in 0.96s

# dmesg | grep -c 'max lookup times reached'
10

# dmesg
[ 259.086086] ocfs2_check_if_ancestor: 1990 callbacks suppressed
[ 259.086092] (stress-ng-dirde,740,1):ocfs2_check_if_ancestor:1091 max lookup times reached, filesystem may have nested directories, src inode: 18007, dest inode: 17940.
...

Signed-off-by: Mauricio Faria de Oliveira <[email protected]>
---
fs/ocfs2/namei.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 3c908e9416af..0043eddabdb8 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1095,8 +1095,8 @@ static int ocfs2_check_if_ancestor(struct ocfs2_super *osb,
child_inode_no = parent_inode_no;

if (++i >= MAX_LOOKUP_TIMES) {
- mlog(ML_NOTICE, "max lookup times reached, filesystem "
- "may have nested directories, "
+ mlog_ratelimited(ML_NOTICE, "max lookup times reached, "
+ "filesystem may have nested directories, "
"src inode: %llu, dest inode: %llu.\n",
(unsigned long long)src_inode_no,
(unsigned long long)dest_inode_no);
--
2.17.1


2020-10-04 03:55:43

by Joseph Qi

[permalink] [raw]
Subject: Re: [PATCH] ocfs2: ratelimit the 'max lookup times reached' notice



On 2020/10/2 06:44, Mauricio Faria de Oliveira wrote:
> Running stress-ng on ocfs2 completely fills the kernel log with
> 'max lookup times reached, filesystem may have nested directories.'
>
> Let's ratelimit this message as done with others in the code.
>
> Test-case:
>
> # mkfs.ocfs2 --mount local $DEV
> # mount $DEV $MNT
> # cd $MNT
>
> # dmesg -C
> # stress-ng --dirdeep 1 --dirdeep-ops 1000
> # dmesg | grep -c 'max lookup times reached'
>
> Before:
>
> # dmesg -C
> # stress-ng --dirdeep 1 --dirdeep-ops 1000
> ...
> stress-ng: info: [11116] successful run completed in 3.03s
>
> # dmesg | grep -c 'max lookup times reached'
> 967
>
> After:
>
> # dmesg -C
> # stress-ng --dirdeep 1 --dirdeep-ops 1000
> ...
> stress-ng: info: [739] successful run completed in 0.96s
>
> # dmesg | grep -c 'max lookup times reached'
> 10
>
> # dmesg
> [ 259.086086] ocfs2_check_if_ancestor: 1990 callbacks suppressed
> [ 259.086092] (stress-ng-dirde,740,1):ocfs2_check_if_ancestor:1091 max lookup times reached, filesystem may have nested directories, src inode: 18007, dest inode: 17940.
> ...
>
> Signed-off-by: Mauricio Faria de Oliveira <[email protected]>

Looks good to me.
Reviewed-by: Joseph Qi <[email protected]>

> ---
> fs/ocfs2/namei.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
> index 3c908e9416af..0043eddabdb8 100644
> --- a/fs/ocfs2/namei.c
> +++ b/fs/ocfs2/namei.c
> @@ -1095,8 +1095,8 @@ static int ocfs2_check_if_ancestor(struct ocfs2_super *osb,
> child_inode_no = parent_inode_no;
>
> if (++i >= MAX_LOOKUP_TIMES) {
> - mlog(ML_NOTICE, "max lookup times reached, filesystem "
> - "may have nested directories, "
> + mlog_ratelimited(ML_NOTICE, "max lookup times reached, "
> + "filesystem may have nested directories, "
> "src inode: %llu, dest inode: %llu.\n",
> (unsigned long long)src_inode_no,
> (unsigned long long)dest_inode_no);
>