diff options
| -rw-r--r-- | fs/nfsd/nfs4state.c | 164 | ||||
| -rw-r--r-- | fs/nfsd/state.h | 12 |
2 files changed, 156 insertions, 20 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a204d7e..ca0db49 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -99,6 +99,7 @@ static struct kmem_cache *odstate_slab; static void free_session(struct nfsd4_session *); static const struct nfsd4_callback_ops nfsd4_cb_recall_ops; +static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops; static bool is_session_dead(struct nfsd4_session *ses) { @@ -210,6 +211,84 @@ static void nfsd4_put_session(struct nfsd4_session *ses) spin_unlock(&nn->client_lock); } +static struct nfsd4_blocked_lock * +find_blocked_lock(struct nfs4_lockowner *lo, struct knfsd_fh *fh, + struct nfsd_net *nn) +{ + struct nfsd4_blocked_lock *cur, *found = NULL; + + spin_lock(&nn->client_lock); + list_for_each_entry(cur, &lo->lo_blocked, nbl_list) { + if (fh_match(fh, &cur->nbl_fh)) { + list_del_init(&cur->nbl_list); + found = cur; + break; + } + } + spin_unlock(&nn->client_lock); + if (found) + posix_unblock_lock(&found->nbl_lock); + return found; +} + +static struct nfsd4_blocked_lock * +find_or_allocate_block(struct nfs4_lockowner *lo, struct knfsd_fh *fh, + struct nfsd_net *nn) +{ + struct nfsd4_blocked_lock *nbl; + + nbl = find_blocked_lock(lo, fh, nn); + if (!nbl) { + nbl= kmalloc(sizeof(*nbl), GFP_KERNEL); + if (nbl) { + fh_copy_shallow(&nbl->nbl_fh, fh); + locks_init_lock(&nbl->nbl_lock); + nfsd4_init_cb(&nbl->nbl_cb, lo->lo_owner.so_client, + &nfsd4_cb_notify_lock_ops, + NFSPROC4_CLNT_CB_NOTIFY_LOCK); + } + } + return nbl; +} + +static void +free_blocked_lock(struct nfsd4_blocked_lock *nbl) +{ + locks_release_private(&nbl->nbl_lock); + kfree(nbl); +} + +static int +nfsd4_cb_notify_lock_done(struct nfsd4_callback *cb, struct rpc_task *task) +{ + /* + * Since this is just an optimization, we don't try very hard if it + * turns out not to succeed. We'll requeue it on NFS4ERR_DELAY, and + * just quit trying on anything else. + */ + switch (task->tk_status) { + case -NFS4ERR_DELAY: + rpc_delay(task, 1 * HZ); + return 0; + default: + return 1; + } +} + +static void +nfsd4_cb_notify_lock_release(struct nfsd4_callback *cb) +{ + struct nfsd4_blocked_lock *nbl = container_of(cb, + struct nfsd4_blocked_lock, nbl_cb); + + free_blocked_lock(nbl); +} + +static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops = { + .done = nfsd4_cb_notify_lock_done, + .release = nfsd4_cb_notify_lock_release, +}; + static inline struct nfs4_stateowner * nfs4_get_stateowner(struct nfs4_stateowner *sop) { @@ -5309,7 +5388,29 @@ nfsd4_fl_put_owner(fl_owner_t owner) nfs4_put_stateowner(&lo->lo_owner); } +static void +nfsd4_lm_notify(struct file_lock *fl) +{ + struct nfs4_lockowner *lo = (struct nfs4_lockowner *)fl->fl_owner; + struct net *net = lo->lo_owner.so_client->net; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct nfsd4_blocked_lock *nbl = container_of(fl, + struct nfsd4_blocked_lock, nbl_lock); + bool queue = false; + + spin_lock(&nn->client_lock); + if (!list_empty(&nbl->nbl_list)) { + list_del_init(&nbl->nbl_list); + queue = true; + } + spin_unlock(&nn->client_lock); + + if (queue) + nfsd4_run_cb(&nbl->nbl_cb); +} + static const struct lock_manager_operations nfsd_posix_mng_ops = { + .lm_notify = nfsd4_lm_notify, .lm_get_owner = nfsd4_fl_get_owner, .lm_put_owner = nfsd4_fl_put_owner, }; @@ -5407,6 +5508,7 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, lo = alloc_stateowner(lockowner_slab, &lock->lk_new_owner, clp); if (!lo) return NULL; + INIT_LIST_HEAD(&lo->lo_blocked); INIT_LIST_HEAD(&lo->lo_owner.so_stateids); lo->lo_owner.so_is_open_owner = 0; lo->lo_owner.so_seqid = lock->lk_new_lock_seqid; @@ -5588,12 +5690,15 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfs4_ol_stateid *open_stp = NULL; struct nfs4_file *fp; struct file *filp = NULL; + struct nfsd4_blocked_lock *nbl = NULL; struct file_lock *file_lock = NULL; struct file_lock *conflock = NULL; __be32 status = 0; int lkflg; int err; bool new = false; + unsigned char fl_type; + unsigned int fl_flags = FL_POSIX; struct net *net = SVC_NET(rqstp); struct nfsd_net *nn = net_generic(net, nfsd_net_id); @@ -5658,46 +5763,55 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, if (!locks_in_grace(net) && lock->lk_reclaim) goto out; - file_lock = locks_alloc_lock(); - if (!file_lock) { - dprintk("NFSD: %s: unable to allocate lock!\n", __func__); - status = nfserr_jukebox; - goto out; - } - fp = lock_stp->st_stid.sc_file; switch (lock->lk_type) { - case NFS4_READ_LT: case NFS4_READW_LT: + if (nfsd4_has_session(cstate)) + fl_flags |= FL_SLEEP; + /* Fallthrough */ + case NFS4_READ_LT: spin_lock(&fp->fi_lock); filp = find_readable_file_locked(fp); if (filp) get_lock_access(lock_stp, NFS4_SHARE_ACCESS_READ); spin_unlock(&fp->fi_lock); - file_lock->fl_type = F_RDLCK; + fl_type = F_RDLCK; break; - case NFS4_WRITE_LT: case NFS4_WRITEW_LT: + if (nfsd4_has_session(cstate)) + fl_flags |= FL_SLEEP; + /* Fallthrough */ + case NFS4_WRITE_LT: spin_lock(&fp->fi_lock); filp = find_writeable_file_locked(fp); if (filp) get_lock_access(lock_stp, NFS4_SHARE_ACCESS_WRITE); spin_unlock(&fp->fi_lock); - file_lock->fl_type = F_WRLCK; + fl_type = F_WRLCK; break; default: status = nfserr_inval; goto out; } + if (!filp) { status = nfserr_openmode; goto out; } + nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn); + if (!nbl) { + dprintk("NFSD: %s: unable to allocate block!\n", __func__); + status = nfserr_jukebox; + goto out; + } + + file_lock = &nbl->nbl_lock; + file_lock->fl_type = fl_type; file_lock->fl_owner = (fl_owner_t)lockowner(nfs4_get_stateowner(&lock_sop->lo_owner)); file_lock->fl_pid = current->tgid; file_lock->fl_file = filp; - file_lock->fl_flags = FL_POSIX; + file_lock->fl_flags = fl_flags; file_lock->fl_lmops = &nfsd_posix_mng_ops; file_lock->fl_start = lock->lk_offset; file_lock->fl_end = last_byte_offset(lock->lk_offset, lock->lk_length); @@ -5710,18 +5824,27 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, goto out; } + if (fl_flags & FL_SLEEP) { + spin_lock(&nn->client_lock); + list_add_tail(&nbl->nbl_list, &lock_sop->lo_blocked); + spin_unlock(&nn->client_lock); + } + err = vfs_lock_file(filp, F_SETLK, file_lock, conflock); - switch (-err) { + switch (err) { case 0: /* success! */ nfs4_inc_and_copy_stateid(&lock->lk_resp_stateid, &lock_stp->st_stid); status = 0; break; - case (EAGAIN): /* conflock holds conflicting lock */ + case FILE_LOCK_DEFERRED: + nbl = NULL; + /* Fallthrough */ + case -EAGAIN: /* conflock holds conflicting lock */ status = nfserr_denied; dprintk("NFSD: nfsd4_lock: conflicting lock found!\n"); nfs4_set_lock_denied(conflock, &lock->lk_denied); break; - case (EDEADLK): + case -EDEADLK: status = nfserr_deadlock; break; default: @@ -5730,6 +5853,15 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, break; } out: + if (nbl) { + /* dequeue it if we queued it before */ + if (fl_flags & FL_SLEEP) { + spin_lock(&nn->client_lock); + list_del_init(&nbl->nbl_list); + spin_unlock(&nn->client_lock); + } + free_blocked_lock(nbl); + } if (filp) fput(filp); if (lock_stp) { @@ -5753,8 +5885,6 @@ out: if (open_stp) nfs4_put_stid(&open_stp->st_stid); nfsd4_bump_seqid(cstate, status); - if (file_lock) - locks_free_lock(file_lock); if (conflock) locks_free_lock(conflock); return status; diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 88d029d..e45c183 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -440,11 +440,11 @@ struct nfs4_openowner { /* * Represents a generic "lockowner". Similar to an openowner. References to it * are held by the lock stateids that are created on its behalf. This object is - * a superset of the nfs4_stateowner struct (or would be if it needed any extra - * fields). + * a superset of the nfs4_stateowner struct. */ struct nfs4_lockowner { - struct nfs4_stateowner lo_owner; /* must be first element */ + struct nfs4_stateowner lo_owner; /* must be first element */ + struct list_head lo_blocked; /* blocked file_locks */ }; static inline struct nfs4_openowner * openowner(struct nfs4_stateowner *so) @@ -580,7 +580,13 @@ static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b) return (s32)(a->si_generation - b->si_generation) > 0; } +/* + * When a client tries to get a lock on a file, we set one of these objects + * on the blocking lock. When the lock becomes free, we can then issue a + * CB_NOTIFY_LOCK to the server. + */ struct nfsd4_blocked_lock { + struct list_head nbl_list; struct file_lock nbl_lock; struct knfsd_fh nbl_fh; struct nfsd4_callback nbl_cb; |
