diff options
Diffstat (limited to 'fs/nfs')
-rw-r--r-- | fs/nfs/delegation.c | 147 | ||||
-rw-r--r-- | fs/nfs/delegation.h | 1 | ||||
-rw-r--r-- | fs/nfs/nfs4proc.c | 3 |
3 files changed, 108 insertions, 43 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 81c5eec..2542cda 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -55,7 +55,8 @@ int nfs4_have_delegation(struct inode *inode, fmode_t flags) flags &= FMODE_READ|FMODE_WRITE; rcu_read_lock(); delegation = rcu_dereference(NFS_I(inode)->delegation); - if (delegation != NULL && (delegation->type & flags) == flags) { + if (delegation != NULL && (delegation->type & flags) == flags && + !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { nfs_mark_delegation_referenced(delegation); ret = 1; } @@ -94,7 +95,9 @@ static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *s { struct nfs_inode *nfsi = NFS_I(inode); struct nfs_open_context *ctx; + struct nfs4_state_owner *sp; struct nfs4_state *state; + unsigned int seq; int err; again: @@ -109,9 +112,13 @@ again: continue; get_nfs_open_context(ctx); spin_unlock(&inode->i_lock); + sp = state->owner; + seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); err = nfs4_open_delegation_recall(ctx, state, stateid); - if (err >= 0) + if (!err) err = nfs_delegation_claim_locks(ctx, state); + if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) + err = -EAGAIN; put_nfs_open_context(ctx); if (err != 0) return err; @@ -182,39 +189,91 @@ static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation } static struct nfs_delegation * +nfs_start_delegation_return_locked(struct nfs_inode *nfsi) +{ + struct nfs_delegation *ret = NULL; + struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); + + if (delegation == NULL) + goto out; + spin_lock(&delegation->lock); + if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) + ret = delegation; + spin_unlock(&delegation->lock); +out: + return ret; +} + +static struct nfs_delegation * +nfs_start_delegation_return(struct nfs_inode *nfsi) +{ + struct nfs_delegation *delegation; + + rcu_read_lock(); + delegation = nfs_start_delegation_return_locked(nfsi); + rcu_read_unlock(); + return delegation; +} + +static void +nfs_abort_delegation_return(struct nfs_delegation *delegation, + struct nfs_client *clp) +{ + + spin_lock(&delegation->lock); + clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); + set_bit(NFS_DELEGATION_RETURN, &delegation->flags); + spin_unlock(&delegation->lock); + set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); +} + +static struct nfs_delegation * nfs_detach_delegation_locked(struct nfs_inode *nfsi, - struct nfs_server *server) + struct nfs_delegation *delegation, + struct nfs_client *clp) { - struct nfs_delegation *delegation = + struct nfs_delegation *deleg_cur = rcu_dereference_protected(nfsi->delegation, - lockdep_is_held(&server->nfs_client->cl_lock)); + lockdep_is_held(&clp->cl_lock)); - if (delegation == NULL) - goto nomatch; + if (deleg_cur == NULL || delegation != deleg_cur) + return NULL; spin_lock(&delegation->lock); + set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); list_del_rcu(&delegation->super_list); delegation->inode = NULL; nfsi->delegation_state = 0; rcu_assign_pointer(nfsi->delegation, NULL); spin_unlock(&delegation->lock); return delegation; -nomatch: - return NULL; } static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, - struct nfs_server *server) + struct nfs_delegation *delegation, + struct nfs_server *server) { struct nfs_client *clp = server->nfs_client; - struct nfs_delegation *delegation; spin_lock(&clp->cl_lock); - delegation = nfs_detach_delegation_locked(nfsi, server); + delegation = nfs_detach_delegation_locked(nfsi, delegation, clp); spin_unlock(&clp->cl_lock); return delegation; } +static struct nfs_delegation * +nfs_inode_detach_delegation(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_server *server = NFS_SERVER(inode); + struct nfs_delegation *delegation; + + delegation = nfs_start_delegation_return(nfsi); + if (delegation == NULL) + return NULL; + return nfs_detach_delegation(nfsi, delegation, server); +} + /** * nfs_inode_set_delegation - set up a delegation on an inode * @inode: inode to which delegation applies @@ -268,7 +327,10 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct delegation = NULL; goto out; } - freeme = nfs_detach_delegation_locked(nfsi, server); + freeme = nfs_detach_delegation_locked(nfsi, + old_delegation, clp); + if (freeme == NULL) + goto out; } list_add_rcu(&delegation->super_list, &server->delegations); nfsi->delegation_state = delegation->type; @@ -292,19 +354,29 @@ out: /* * Basic procedure for returning a delegation to the server */ -static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) +static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync) { + struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; struct nfs_inode *nfsi = NFS_I(inode); int err; - /* - * Guard against new delegated open/lock/unlock calls and against - * state recovery - */ - down_write(&nfsi->rwsem); - err = nfs_delegation_claim_opens(inode, &delegation->stateid); - up_write(&nfsi->rwsem); - if (err) + if (delegation == NULL) + return 0; + do { + err = nfs_delegation_claim_opens(inode, &delegation->stateid); + if (!issync || err != -EAGAIN) + break; + /* + * Guard against state recovery + */ + err = nfs4_wait_clnt_recover(clp); + } while (err == 0); + + if (err) { + nfs_abort_delegation_return(delegation, clp); + goto out; + } + if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode))) goto out; err = nfs_do_return_delegation(inode, delegation, issync); @@ -340,13 +412,10 @@ restart: inode = nfs_delegation_grab_inode(delegation); if (inode == NULL) continue; - delegation = nfs_detach_delegation(NFS_I(inode), - server); + delegation = nfs_start_delegation_return_locked(NFS_I(inode)); rcu_read_unlock(); - if (delegation != NULL) - err = __nfs_inode_return_delegation(inode, - delegation, 0); + err = nfs_end_delegation_return(inode, delegation, 0); iput(inode); if (!err) goto restart; @@ -367,15 +436,11 @@ restart: */ void nfs_inode_return_delegation_noreclaim(struct inode *inode) { - struct nfs_server *server = NFS_SERVER(inode); - struct nfs_inode *nfsi = NFS_I(inode); struct nfs_delegation *delegation; - if (rcu_access_pointer(nfsi->delegation) != NULL) { - delegation = nfs_detach_delegation(nfsi, server); - if (delegation != NULL) - nfs_do_return_delegation(inode, delegation, 0); - } + delegation = nfs_inode_detach_delegation(inode); + if (delegation != NULL) + nfs_do_return_delegation(inode, delegation, 0); } /** @@ -390,18 +455,14 @@ void nfs_inode_return_delegation_noreclaim(struct inode *inode) */ int nfs4_inode_return_delegation(struct inode *inode) { - struct nfs_server *server = NFS_SERVER(inode); struct nfs_inode *nfsi = NFS_I(inode); struct nfs_delegation *delegation; int err = 0; nfs_wb_all(inode); - if (rcu_access_pointer(nfsi->delegation) != NULL) { - delegation = nfs_detach_delegation(nfsi, server); - if (delegation != NULL) { - err = __nfs_inode_return_delegation(inode, delegation, 1); - } - } + delegation = nfs_start_delegation_return(nfsi); + if (delegation != NULL) + err = nfs_end_delegation_return(inode, delegation, 1); return err; } @@ -471,7 +532,7 @@ void nfs_remove_bad_delegation(struct inode *inode) { struct nfs_delegation *delegation; - delegation = nfs_detach_delegation(NFS_I(inode), NFS_SERVER(inode)); + delegation = nfs_inode_detach_delegation(inode); if (delegation) { nfs_inode_find_state_and_recover(inode, &delegation->stateid); nfs_free_delegation(delegation); @@ -649,7 +710,7 @@ restart: if (inode == NULL) continue; delegation = nfs_detach_delegation(NFS_I(inode), - server); + delegation, server); rcu_read_unlock(); if (delegation != NULL) diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h index bbc6a4d..d54d4fc 100644 --- a/fs/nfs/delegation.h +++ b/fs/nfs/delegation.h @@ -29,6 +29,7 @@ enum { NFS_DELEGATION_NEED_RECLAIM = 0, NFS_DELEGATION_RETURN, NFS_DELEGATION_REFERENCED, + NFS_DELEGATION_RETURNING, }; int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res); diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 92584c1..a1e89e2 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -896,6 +896,8 @@ static int can_open_delegated(struct nfs_delegation *delegation, fmode_t fmode) return 0; if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags)) return 0; + if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) + return 0; nfs_mark_delegation_referenced(delegation); return 1; } @@ -973,6 +975,7 @@ static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stat spin_lock(&deleg_cur->lock); if (nfsi->delegation != deleg_cur || + test_bit(NFS_DELEGATION_RETURNING, &deleg_cur->flags) || (deleg_cur->type & fmode) != fmode) goto no_delegation_unlock; |