diff options
Diffstat (limited to 'fs/nfs/delegation.c')
-rw-r--r-- | fs/nfs/delegation.c | 89 |
1 files changed, 53 insertions, 36 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 2563bebc4c6..30163454397 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -10,6 +10,7 @@ #include <linux/kthread.h> #include <linux/module.h> #include <linux/sched.h> +#include <linux/slab.h> #include <linux/smp_lock.h> #include <linux/spinlock.h> @@ -23,6 +24,8 @@ static void nfs_do_free_delegation(struct nfs_delegation *delegation) { + if (delegation->cred) + put_rpccred(delegation->cred); kfree(delegation); } @@ -35,13 +38,7 @@ static void nfs_free_delegation_callback(struct rcu_head *head) static void nfs_free_delegation(struct nfs_delegation *delegation) { - struct rpc_cred *cred; - - cred = rcu_dereference(delegation->cred); - rcu_assign_pointer(delegation->cred, NULL); call_rcu(&delegation->rcu, nfs_free_delegation_callback); - if (cred) - put_rpccred(cred); } void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) @@ -128,21 +125,35 @@ again: */ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res) { - struct nfs_delegation *delegation = NFS_I(inode)->delegation; - struct rpc_cred *oldcred; + struct nfs_delegation *delegation; + struct rpc_cred *oldcred = NULL; - if (delegation == NULL) - return; - memcpy(delegation->stateid.data, res->delegation.data, - sizeof(delegation->stateid.data)); - delegation->type = res->delegation_type; - delegation->maxsize = res->maxsize; - oldcred = delegation->cred; - delegation->cred = get_rpccred(cred); - clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); - NFS_I(inode)->delegation_state = delegation->type; - smp_wmb(); - put_rpccred(oldcred); + rcu_read_lock(); + delegation = rcu_dereference(NFS_I(inode)->delegation); + if (delegation != NULL) { + spin_lock(&delegation->lock); + if (delegation->inode != NULL) { + memcpy(delegation->stateid.data, res->delegation.data, + sizeof(delegation->stateid.data)); + delegation->type = res->delegation_type; + delegation->maxsize = res->maxsize; + oldcred = delegation->cred; + delegation->cred = get_rpccred(cred); + clear_bit(NFS_DELEGATION_NEED_RECLAIM, + &delegation->flags); + NFS_I(inode)->delegation_state = delegation->type; + spin_unlock(&delegation->lock); + put_rpccred(oldcred); + rcu_read_unlock(); + } else { + /* We appear to have raced with a delegation return. */ + spin_unlock(&delegation->lock); + rcu_read_unlock(); + nfs_inode_set_delegation(inode, cred, res); + } + } else { + rcu_read_unlock(); + } } static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) @@ -165,9 +176,13 @@ static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation return inode; } -static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid) +static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, + const nfs4_stateid *stateid, + struct nfs_client *clp) { - struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); + struct nfs_delegation *delegation = + rcu_dereference_protected(nfsi->delegation, + lockdep_is_held(&clp->cl_lock)); if (delegation == NULL) goto nomatch; @@ -194,11 +209,11 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct { struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; struct nfs_inode *nfsi = NFS_I(inode); - struct nfs_delegation *delegation; + struct nfs_delegation *delegation, *old_delegation; struct nfs_delegation *freeme = NULL; int status = 0; - delegation = kmalloc(sizeof(*delegation), GFP_KERNEL); + delegation = kmalloc(sizeof(*delegation), GFP_NOFS); if (delegation == NULL) return -ENOMEM; memcpy(delegation->stateid.data, res->delegation.data, @@ -212,10 +227,12 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct spin_lock_init(&delegation->lock); spin_lock(&clp->cl_lock); - if (rcu_dereference(nfsi->delegation) != NULL) { - if (memcmp(&delegation->stateid, &nfsi->delegation->stateid, - sizeof(delegation->stateid)) == 0 && - delegation->type == nfsi->delegation->type) { + old_delegation = rcu_dereference_protected(nfsi->delegation, + lockdep_is_held(&clp->cl_lock)); + if (old_delegation != NULL) { + if (memcmp(&delegation->stateid, &old_delegation->stateid, + sizeof(old_delegation->stateid)) == 0 && + delegation->type == old_delegation->type) { goto out; } /* @@ -225,12 +242,12 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct dfprintk(FILE, "%s: server %s handed out " "a duplicate delegation!\n", __func__, clp->cl_hostname); - if (delegation->type <= nfsi->delegation->type) { + if (delegation->type <= old_delegation->type) { freeme = delegation; delegation = NULL; goto out; } - freeme = nfs_detach_delegation_locked(nfsi, NULL); + freeme = nfs_detach_delegation_locked(nfsi, NULL, clp); } list_add_rcu(&delegation->super_list, &clp->cl_delegations); nfsi->delegation_state = delegation->type; @@ -300,7 +317,7 @@ restart: if (inode == NULL) continue; spin_lock(&clp->cl_lock); - delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL); + delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL, clp); spin_unlock(&clp->cl_lock); rcu_read_unlock(); if (delegation != NULL) { @@ -329,9 +346,9 @@ void nfs_inode_return_delegation_noreclaim(struct inode *inode) struct nfs_inode *nfsi = NFS_I(inode); struct nfs_delegation *delegation; - if (rcu_dereference(nfsi->delegation) != NULL) { + if (rcu_access_pointer(nfsi->delegation) != NULL) { spin_lock(&clp->cl_lock); - delegation = nfs_detach_delegation_locked(nfsi, NULL); + delegation = nfs_detach_delegation_locked(nfsi, NULL, clp); spin_unlock(&clp->cl_lock); if (delegation != NULL) nfs_do_return_delegation(inode, delegation, 0); @@ -345,9 +362,9 @@ int nfs_inode_return_delegation(struct inode *inode) struct nfs_delegation *delegation; int err = 0; - if (rcu_dereference(nfsi->delegation) != NULL) { + if (rcu_access_pointer(nfsi->delegation) != NULL) { spin_lock(&clp->cl_lock); - delegation = nfs_detach_delegation_locked(nfsi, NULL); + delegation = nfs_detach_delegation_locked(nfsi, NULL, clp); spin_unlock(&clp->cl_lock); if (delegation != NULL) { nfs_msync_inode(inode); @@ -525,7 +542,7 @@ restart: if (inode == NULL) continue; spin_lock(&clp->cl_lock); - delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL); + delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL, clp); spin_unlock(&clp->cl_lock); rcu_read_unlock(); if (delegation != NULL) |