2020-04-16 00:04:17

by Zhiqiang Liu

Subject: [PATCH] dcache: unlock inode->i_lock before goto restart tag in, d_prune_aliases

From: Zhiqiang Liu <[email protected]>

coccicheck reports:
fs/dcache.c:1027:1-10: second lock on line 1027

In d_prune_aliases, before goto restart we should unlock
inode->i_lock.

Fixes: 29355c3904e ("d_prune_alias(): just lock the parent and call __dentry_kill()")
Signed-off-by: Zhiqiang Liu <[email protected]>
Signed-off-by: Feilong Lin <[email protected]>
---
fs/dcache.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/dcache.c b/fs/dcache.c
index b280e07e162b..1532ebe9d9ca 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1030,6 +1030,7 @@ void d_prune_aliases(struct inode *inode)
if (!dentry->d_lockref.count) {
struct dentry *parent = lock_parent(dentry);
if (likely(!dentry->d_lockref.count)) {
+ spin_unlock(&inode->i_lock);
__dentry_kill(dentry);
dput(parent);
goto restart;
--
2.19.1

2020-04-16 02:00:06

by Zhiqiang Liu

Subject: Re: [PATCH] dcache: unlock inode->i_lock before goto restart tag in, d_prune_aliases

On 2020/4/16 9:46, Eric Biggers wrote:
> On Wed, Apr 15, 2020 at 09:20:33PM +0800, Zhiqiang Liu wrote:
>> From: Zhiqiang Liu <[email protected]>
>>
>> coccicheck reports:
>> fs/dcache.c:1027:1-10: second lock on line 1027
>>
>> In d_prune_aliases, before goto restart we should unlock
>> inode->i_lock.
>>
>> Fixes: 29355c3904e ("d_prune_alias(): just lock the parent and call __dentry_kill()")
>> Signed-off-by: Zhiqiang Liu <[email protected]>
>> Signed-off-by: Feilong Lin <[email protected]>
>> ---
>> fs/dcache.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/fs/dcache.c b/fs/dcache.c
>> index b280e07e162b..1532ebe9d9ca 100644
>> --- a/fs/dcache.c
>> +++ b/fs/dcache.c
>> @@ -1030,6 +1030,7 @@ void d_prune_aliases(struct inode *inode)
>> if (!dentry->d_lockref.count) {
>> struct dentry *parent = lock_parent(dentry);
>> if (likely(!dentry->d_lockref.count)) {
>> + spin_unlock(&inode->i_lock);
>> __dentry_kill(dentry);
>> dput(parent);
>> goto restart;
>> --
>
> Doesn't __dentry_kill() already do the unlock, via dentry_unlink_inode()?
>
> - Eric
>
Yes, you are right. Sorry for that. Please ignore this patch.
> .
>

2020-04-16 02:02:06

by Eric Biggers

Subject: Re: [PATCH] dcache: unlock inode->i_lock before goto restart tag in, d_prune_aliases

On Wed, Apr 15, 2020 at 09:20:33PM +0800, Zhiqiang Liu wrote:
> From: Zhiqiang Liu <[email protected]>
>
> coccicheck reports:
> fs/dcache.c:1027:1-10:?second?lock?on?line?1027
>
> In d_prune_aliases, before goto restart we should unlock
> inode->i_lock.
>
> Fixes: 29355c3904e ("d_prune_alias(): just lock the parent and call __dentry_kill()")
> Signed-off-by: Zhiqiang Liu <[email protected]>
> Signed-off-by: Feilong Lin <[email protected]>
> ---
> fs/dcache.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/dcache.c b/fs/dcache.c
> index b280e07e162b..1532ebe9d9ca 100644
> --- a/fs/dcache.c
> +++ b/fs/dcache.c
> @@ -1030,6 +1030,7 @@ void d_prune_aliases(struct inode *inode)
> if (!dentry->d_lockref.count) {
> struct dentry *parent = lock_parent(dentry);
> if (likely(!dentry->d_lockref.count)) {
> + spin_unlock(&inode->i_lock);
> __dentry_kill(dentry);
> dput(parent);
> goto restart;
> --

Doesn't __dentry_kill() already do the unlock, via dentry_unlink_inode()?

- Eric