diff mbox series

[3/3] NFS: Avoid unnecessary rescanning of the per-server delegation list

Message ID 3fe20b13641fe569107f1474d17befd8caa0b076.1724263426.git.trond.myklebust@hammerspace.com (mailing list archive)
State New
Headers show
Series [1/3] NFSv4: Add missing rescheduling points in nfs_client_return_marked_delegations | expand

Commit Message

Trond Myklebust Aug. 21, 2024, 6:05 p.m. UTC 
From: Trond Myklebust <trond.myklebust@hammerspace.com>

If the call to nfs_delegation_grab_inode() fails, we will not have
dropped any locks that require us to rescan the list.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/delegation.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

Comments

Jeff Layton Aug. 22, 2024, 12:19 p.m. UTC | #1 
On Wed, 2024-08-21 at 14:05 -0400, trondmy@kernel.org wrote:
> From: Trond Myklebust <trond.myklebust@hammerspace.com>
> 
> If the call to nfs_delegation_grab_inode() fails, we will not have
> dropped any locks that require us to rescan the list.
> 
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> ---
>  fs/nfs/delegation.c | 15 +++++----------
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
> index d5edb3b3eeef..20cb2008f9e4 100644
> --- a/fs/nfs/delegation.c
> +++ b/fs/nfs/delegation.c
> @@ -647,6 +647,9 @@ static int nfs_server_return_marked_delegations(struct nfs_server *server,
>  				prev = delegation;
>  			continue;
>  		}
> +		inode = nfs_delegation_grab_inode(delegation);
> +		if (inode == NULL)
> +			continue;
>  
>  		if (prev) {
>  			struct inode *tmp = nfs_delegation_grab_inode(prev);
> @@ -657,12 +660,6 @@ static int nfs_server_return_marked_delegations(struct nfs_server *server,
>  			}
>  		}
>  
> -		inode = nfs_delegation_grab_inode(delegation);
> -		if (inode == NULL) {
> -			rcu_read_unlock();
> -			iput(to_put);
> -			goto restart;
> -		}
>  		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
>  		rcu_read_unlock();
>  
> @@ -1184,7 +1181,6 @@ static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
>  	struct inode *inode;
>  restart:
>  	rcu_read_lock();
> -restart_locked:
>  	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
>  		if (test_bit(NFS_DELEGATION_INODE_FREEING,
>  					&delegation->flags) ||
> @@ -1195,7 +1191,7 @@ static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
>  			continue;
>  		inode = nfs_delegation_grab_inode(delegation);
>  		if (inode == NULL)
> -			goto restart_locked;
> +			continue;
>  		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
>  		rcu_read_unlock();
>  		if (delegation != NULL) {
> @@ -1318,7 +1314,6 @@ static int nfs_server_reap_expired_delegations(struct nfs_server *server,
>  
>  restart:
>  	rcu_read_lock();
> -restart_locked:
>  	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
>  		if (test_bit(NFS_DELEGATION_INODE_FREEING,
>  					&delegation->flags) ||
> @@ -1330,7 +1325,7 @@ static int nfs_server_reap_expired_delegations(struct nfs_server *server,
>  			continue;
>  		inode = nfs_delegation_grab_inode(delegation);
>  		if (inode == NULL)
> -			goto restart_locked;
> +			continue;
>  		spin_lock(&delegation->lock);
>  		cred = get_cred_rcu(delegation->cred);
>  		nfs4_stateid_copy(&stateid, &delegation->stateid);

Reviewed-by: Jeff Layton <jlayton@kernel.org>
diff mbox series

Patch

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index d5edb3b3eeef..20cb2008f9e4 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -647,6 +647,9 @@  static int nfs_server_return_marked_delegations(struct nfs_server *server,
 				prev = delegation;
 			continue;
 		}
+		inode = nfs_delegation_grab_inode(delegation);
+		if (inode == NULL)
+			continue;
 
 		if (prev) {
 			struct inode *tmp = nfs_delegation_grab_inode(prev);
@@ -657,12 +660,6 @@  static int nfs_server_return_marked_delegations(struct nfs_server *server,
 			}
 		}
 
-		inode = nfs_delegation_grab_inode(delegation);
-		if (inode == NULL) {
-			rcu_read_unlock();
-			iput(to_put);
-			goto restart;
-		}
 		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
 		rcu_read_unlock();
 
@@ -1184,7 +1181,6 @@  static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
 	struct inode *inode;
 restart:
 	rcu_read_lock();
-restart_locked:
 	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
 		if (test_bit(NFS_DELEGATION_INODE_FREEING,
 					&delegation->flags) ||
@@ -1195,7 +1191,7 @@  static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
 			continue;
 		inode = nfs_delegation_grab_inode(delegation);
 		if (inode == NULL)
-			goto restart_locked;
+			continue;
 		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
 		rcu_read_unlock();
 		if (delegation != NULL) {
@@ -1318,7 +1314,6 @@  static int nfs_server_reap_expired_delegations(struct nfs_server *server,
 
 restart:
 	rcu_read_lock();
-restart_locked:
 	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
 		if (test_bit(NFS_DELEGATION_INODE_FREEING,
 					&delegation->flags) ||
@@ -1330,7 +1325,7 @@  static int nfs_server_reap_expired_delegations(struct nfs_server *server,
 			continue;
 		inode = nfs_delegation_grab_inode(delegation);
 		if (inode == NULL)
-			goto restart_locked;
+			continue;
 		spin_lock(&delegation->lock);
 		cred = get_cred_rcu(delegation->cred);
 		nfs4_stateid_copy(&stateid, &delegation->stateid);