[RFC PATCH] ceph: fix statx AT_STATX_DONT_SYNC vs AT_STATX_FORCE_SYNC check

[RFC PATCH] ceph: fix statx AT_STATX_DONT_SYNC vs AT_STATX_FORCE_SYNC check

[xiubli]

From: Xiubo Li <xiubli@redhat.com>

From the posix and the initial statx supporting commit comments,
the AT_STATX_DONT_SYNC is a lightweight stat flag and the
AT_STATX_FORCE_SYNC is a heaverweight one. And also checked all
the other current usage about these two flags they are all doing
the same, that is only when the AT_STATX_FORCE_SYNC is not set
and the AT_STATX_DONT_SYNC is set will they skip sync retriving
the attributes from storage.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
---
 fs/ceph/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 6788a1f88eb6..1ee6685def83 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -2887,7 +2887,7 @@ int ceph_getattr(struct user_namespace *mnt_userns, const struct path *path,
 		return -ESTALE;
 
 	/* Skip the getattr altogether if we're asked not to sync */
-	if (!(flags & AT_STATX_DONT_SYNC)) {
+	if ((flags & AT_STATX_SYNC_TYPE) != AT_STATX_DONT_SYNC) {
 		err = ceph_do_getattr(inode,
 				statx_to_caps(request_mask, inode->i_mode),
 				flags & AT_STATX_FORCE_SYNC);
-- 
2.27.0

Re: [RFC PATCH] ceph: fix statx AT_STATX_DONT_SYNC vs AT_STATX_FORCE_SYNC check

[David Howells]

xiubli@redhat.com wrote:

> From the posix and the initial statx supporting commit comments,
> the AT_STATX_DONT_SYNC is a lightweight stat flag and the
> AT_STATX_FORCE_SYNC is a heaverweight one.

They're not flags.  It's an enumeration overlain on the at_flags parameter
because syscalls have a limited number of parameters.

> And also checked all
> the other current usage about these two flags they are all doing
> the same, that is only when the AT_STATX_FORCE_SYNC is not set
> and the AT_STATX_DONT_SYNC is set will they skip sync retriving
> the attributes from storage.
> 
> Signed-off-by: Xiubo Li <xiubli@redhat.com>

Reviewed-by: David Howells <dhowells@redhat.com>

Re: [RFC PATCH] ceph: fix statx AT_STATX_DONT_SYNC vs AT_STATX_FORCE_SYNC check

[Xiubo Li]

On 4/11/22 5:43 PM, David Howells wrote:
> xiubli@redhat.com wrote:
>
>>  From the posix and the initial statx supporting commit comments,
>> the AT_STATX_DONT_SYNC is a lightweight stat flag and the
>> AT_STATX_FORCE_SYNC is a heaverweight one.
> They're not flags.  It's an enumeration overlain on the at_flags parameter
> because syscalls have a limited number of parameters.
Okay, will fix this.
>> And also checked all
>> the other current usage about these two flags they are all doing
>> the same, that is only when the AT_STATX_FORCE_SYNC is not set
>> and the AT_STATX_DONT_SYNC is set will they skip sync retriving
>> the attributes from storage.
>>
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
> Reviewed-by: David Howells <dhowells@redhat.com>

Thanks David.

-- Xiubo


>