Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
David Howells | 4165 | 96.30% | 43 | 81.13% |
Wang Lei | 68 | 1.57% | 2 | 3.77% |
Andrew Morton | 60 | 1.39% | 1 | 1.89% |
Sven Schnelle | 19 | 0.44% | 2 | 3.77% |
Christoph Hellwig | 3 | 0.07% | 1 | 1.89% |
Peter Zijlstra | 3 | 0.07% | 1 | 1.89% |
Alexey Dobriyan | 3 | 0.07% | 1 | 1.89% |
Al Viro | 2 | 0.05% | 1 | 1.89% |
Thomas Gleixner | 2 | 0.05% | 1 | 1.89% |
Total | 4325 | 53 |
// SPDX-License-Identifier: GPL-2.0-or-later /* AFS cell and server record management * * Copyright (C) 2002, 2017 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/slab.h> #include <linux/key.h> #include <linux/ctype.h> #include <linux/dns_resolver.h> #include <linux/sched.h> #include <linux/inet.h> #include <linux/namei.h> #include <keys/rxrpc-type.h> #include "internal.h" static unsigned __read_mostly afs_cell_gc_delay = 10; static unsigned __read_mostly afs_cell_min_ttl = 10 * 60; static unsigned __read_mostly afs_cell_max_ttl = 24 * 60 * 60; static atomic_t cell_debug_id; static void afs_queue_cell_manager(struct afs_net *); static void afs_manage_cell_work(struct work_struct *); static void afs_dec_cells_outstanding(struct afs_net *net) { if (atomic_dec_and_test(&net->cells_outstanding)) wake_up_var(&net->cells_outstanding); } /* * Set the cell timer to fire after a given delay, assuming it's not already * set for an earlier time. */ static void afs_set_cell_timer(struct afs_net *net, time64_t delay) { if (net->live) { atomic_inc(&net->cells_outstanding); if (timer_reduce(&net->cells_timer, jiffies + delay * HZ)) afs_dec_cells_outstanding(net); } else { afs_queue_cell_manager(net); } } /* * Look up and get an activation reference on a cell record. The caller must * hold net->cells_lock at least read-locked. */ static struct afs_cell *afs_find_cell_locked(struct afs_net *net, const char *name, unsigned int namesz, enum afs_cell_trace reason) { struct afs_cell *cell = NULL; struct rb_node *p; int n; _enter("%*.*s", namesz, namesz, name); if (name && namesz == 0) return ERR_PTR(-EINVAL); if (namesz > AFS_MAXCELLNAME) return ERR_PTR(-ENAMETOOLONG); if (!name) { cell = net->ws_cell; if (!cell) return ERR_PTR(-EDESTADDRREQ); goto found; } p = net->cells.rb_node; while (p) { cell = rb_entry(p, struct afs_cell, net_node); n = strncasecmp(cell->name, name, min_t(size_t, cell->name_len, namesz)); if (n == 0) n = cell->name_len - namesz; if (n < 0) p = p->rb_left; else if (n > 0) p = p->rb_right; else goto found; } return ERR_PTR(-ENOENT); found: return afs_use_cell(cell, reason); } /* * Look up and get an activation reference on a cell record. */ struct afs_cell *afs_find_cell(struct afs_net *net, const char *name, unsigned int namesz, enum afs_cell_trace reason) { struct afs_cell *cell; down_read(&net->cells_lock); cell = afs_find_cell_locked(net, name, namesz, reason); up_read(&net->cells_lock); return cell; } /* * Set up a cell record and fill in its name, VL server address list and * allocate an anonymous key */ static struct afs_cell *afs_alloc_cell(struct afs_net *net, const char *name, unsigned int namelen, const char *addresses) { struct afs_vlserver_list *vllist; struct afs_cell *cell; int i, ret; ASSERT(name); if (namelen == 0) return ERR_PTR(-EINVAL); if (namelen > AFS_MAXCELLNAME) { _leave(" = -ENAMETOOLONG"); return ERR_PTR(-ENAMETOOLONG); } /* Prohibit cell names that contain unprintable chars, '/' and '@' or * that begin with a dot. This also precludes "@cell". */ if (name[0] == '.') return ERR_PTR(-EINVAL); for (i = 0; i < namelen; i++) { char ch = name[i]; if (!isprint(ch) || ch == '/' || ch == '@') return ERR_PTR(-EINVAL); } _enter("%*.*s,%s", namelen, namelen, name, addresses); cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL); if (!cell) { _leave(" = -ENOMEM"); return ERR_PTR(-ENOMEM); } cell->name = kmalloc(namelen + 1, GFP_KERNEL); if (!cell->name) { kfree(cell); return ERR_PTR(-ENOMEM); } cell->net = net; cell->name_len = namelen; for (i = 0; i < namelen; i++) cell->name[i] = tolower(name[i]); cell->name[i] = 0; refcount_set(&cell->ref, 1); atomic_set(&cell->active, 0); INIT_WORK(&cell->manager, afs_manage_cell_work); init_rwsem(&cell->vs_lock); cell->volumes = RB_ROOT; INIT_HLIST_HEAD(&cell->proc_volumes); seqlock_init(&cell->volume_lock); cell->fs_servers = RB_ROOT; seqlock_init(&cell->fs_lock); rwlock_init(&cell->vl_servers_lock); cell->flags = (1 << AFS_CELL_FL_CHECK_ALIAS); /* Provide a VL server list, filling it in if we were given a list of * addresses to use. */ if (addresses) { vllist = afs_parse_text_addrs(net, addresses, strlen(addresses), ':', VL_SERVICE, AFS_VL_PORT); if (IS_ERR(vllist)) { ret = PTR_ERR(vllist); goto parse_failed; } vllist->source = DNS_RECORD_FROM_CONFIG; vllist->status = DNS_LOOKUP_NOT_DONE; cell->dns_expiry = TIME64_MAX; } else { ret = -ENOMEM; vllist = afs_alloc_vlserver_list(0); if (!vllist) goto error; vllist->source = DNS_RECORD_UNAVAILABLE; vllist->status = DNS_LOOKUP_NOT_DONE; cell->dns_expiry = ktime_get_real_seconds(); } rcu_assign_pointer(cell->vl_servers, vllist); cell->dns_source = vllist->source; cell->dns_status = vllist->status; smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */ atomic_inc(&net->cells_outstanding); cell->debug_id = atomic_inc_return(&cell_debug_id); trace_afs_cell(cell->debug_id, 1, 0, afs_cell_trace_alloc); _leave(" = %p", cell); return cell; parse_failed: if (ret == -EINVAL) printk(KERN_ERR "kAFS: bad VL server IP address\n"); error: kfree(cell->name); kfree(cell); _leave(" = %d", ret); return ERR_PTR(ret); } /* * afs_lookup_cell - Look up or create a cell record. * @net: The network namespace * @name: The name of the cell. * @namesz: The strlen of the cell name. * @vllist: A colon/comma separated list of numeric IP addresses or NULL. * @excl: T if an error should be given if the cell name already exists. * * Look up a cell record by name and query the DNS for VL server addresses if * needed. Note that that actual DNS query is punted off to the manager thread * so that this function can return immediately if interrupted whilst allowing * cell records to be shared even if not yet fully constructed. */ struct afs_cell *afs_lookup_cell(struct afs_net *net, const char *name, unsigned int namesz, const char *vllist, bool excl) { struct afs_cell *cell, *candidate, *cursor; struct rb_node *parent, **pp; enum afs_cell_state state; int ret, n; _enter("%s,%s", name, vllist); if (!excl) { cell = afs_find_cell(net, name, namesz, afs_cell_trace_use_lookup); if (!IS_ERR(cell)) goto wait_for_cell; } /* Assume we're probably going to create a cell and preallocate and * mostly set up a candidate record. We can then use this to stash the * name, the net namespace and VL server addresses. * * We also want to do this before we hold any locks as it may involve * upcalling to userspace to make DNS queries. */ candidate = afs_alloc_cell(net, name, namesz, vllist); if (IS_ERR(candidate)) { _leave(" = %ld", PTR_ERR(candidate)); return candidate; } /* Find the insertion point and check to see if someone else added a * cell whilst we were allocating. */ down_write(&net->cells_lock); pp = &net->cells.rb_node; parent = NULL; while (*pp) { parent = *pp; cursor = rb_entry(parent, struct afs_cell, net_node); n = strncasecmp(cursor->name, name, min_t(size_t, cursor->name_len, namesz)); if (n == 0) n = cursor->name_len - namesz; if (n < 0) pp = &(*pp)->rb_left; else if (n > 0) pp = &(*pp)->rb_right; else goto cell_already_exists; } cell = candidate; candidate = NULL; atomic_set(&cell->active, 2); trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), 2, afs_cell_trace_insert); rb_link_node_rcu(&cell->net_node, parent, pp); rb_insert_color(&cell->net_node, &net->cells); up_write(&net->cells_lock); afs_queue_cell(cell, afs_cell_trace_get_queue_new); wait_for_cell: trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), atomic_read(&cell->active), afs_cell_trace_wait); _debug("wait_for_cell"); wait_var_event(&cell->state, ({ state = smp_load_acquire(&cell->state); /* vs error */ state == AFS_CELL_ACTIVE || state == AFS_CELL_REMOVED; })); /* Check the state obtained from the wait check. */ if (state == AFS_CELL_REMOVED) { ret = cell->error; goto error; } _leave(" = %p [cell]", cell); return cell; cell_already_exists: _debug("cell exists"); cell = cursor; if (excl) { ret = -EEXIST; } else { afs_use_cell(cursor, afs_cell_trace_use_lookup); ret = 0; } up_write(&net->cells_lock); if (candidate) afs_put_cell(candidate, afs_cell_trace_put_candidate); if (ret == 0) goto wait_for_cell; goto error_noput; error: afs_unuse_cell(net, cell, afs_cell_trace_unuse_lookup); error_noput: _leave(" = %d [error]", ret); return ERR_PTR(ret); } /* * set the root cell information * - can be called with a module parameter string * - can be called from a write to /proc/fs/afs/rootcell */ int afs_cell_init(struct afs_net *net, const char *rootcell) { struct afs_cell *old_root, *new_root; const char *cp, *vllist; size_t len; _enter(""); if (!rootcell) { /* module is loaded with no parameters, or built statically. * - in the future we might initialize cell DB here. */ _leave(" = 0 [no root]"); return 0; } cp = strchr(rootcell, ':'); if (!cp) { _debug("kAFS: no VL server IP addresses specified"); vllist = NULL; len = strlen(rootcell); } else { vllist = cp + 1; len = cp - rootcell; } /* allocate a cell record for the root cell */ new_root = afs_lookup_cell(net, rootcell, len, vllist, false); if (IS_ERR(new_root)) { _leave(" = %ld", PTR_ERR(new_root)); return PTR_ERR(new_root); } if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags)) afs_use_cell(new_root, afs_cell_trace_use_pin); /* install the new cell */ down_write(&net->cells_lock); afs_see_cell(new_root, afs_cell_trace_see_ws); old_root = net->ws_cell; net->ws_cell = new_root; up_write(&net->cells_lock); afs_unuse_cell(net, old_root, afs_cell_trace_unuse_ws); _leave(" = 0"); return 0; } /* * Update a cell's VL server address list from the DNS. */ static int afs_update_cell(struct afs_cell *cell) { struct afs_vlserver_list *vllist, *old = NULL, *p; unsigned int min_ttl = READ_ONCE(afs_cell_min_ttl); unsigned int max_ttl = READ_ONCE(afs_cell_max_ttl); time64_t now, expiry = 0; int ret = 0; _enter("%s", cell->name); vllist = afs_dns_query(cell, &expiry); if (IS_ERR(vllist)) { ret = PTR_ERR(vllist); _debug("%s: fail %d", cell->name, ret); if (ret == -ENOMEM) goto out_wake; vllist = afs_alloc_vlserver_list(0); if (!vllist) { if (ret >= 0) ret = -ENOMEM; goto out_wake; } switch (ret) { case -ENODATA: case -EDESTADDRREQ: vllist->status = DNS_LOOKUP_GOT_NOT_FOUND; break; case -EAGAIN: case -ECONNREFUSED: vllist->status = DNS_LOOKUP_GOT_TEMP_FAILURE; break; default: vllist->status = DNS_LOOKUP_GOT_LOCAL_FAILURE; break; } } _debug("%s: got list %d %d", cell->name, vllist->source, vllist->status); cell->dns_status = vllist->status; now = ktime_get_real_seconds(); if (min_ttl > max_ttl) max_ttl = min_ttl; if (expiry < now + min_ttl) expiry = now + min_ttl; else if (expiry > now + max_ttl) expiry = now + max_ttl; _debug("%s: status %d", cell->name, vllist->status); if (vllist->source == DNS_RECORD_UNAVAILABLE) { switch (vllist->status) { case DNS_LOOKUP_GOT_NOT_FOUND: /* The DNS said that the cell does not exist or there * weren't any addresses to be had. */ cell->dns_expiry = expiry; break; case DNS_LOOKUP_BAD: case DNS_LOOKUP_GOT_LOCAL_FAILURE: case DNS_LOOKUP_GOT_TEMP_FAILURE: case DNS_LOOKUP_GOT_NS_FAILURE: default: cell->dns_expiry = now + 10; break; } } else { cell->dns_expiry = expiry; } /* Replace the VL server list if the new record has servers or the old * record doesn't. */ write_lock(&cell->vl_servers_lock); p = rcu_dereference_protected(cell->vl_servers, true); if (vllist->nr_servers > 0 || p->nr_servers == 0) { rcu_assign_pointer(cell->vl_servers, vllist); cell->dns_source = vllist->source; old = p; } write_unlock(&cell->vl_servers_lock); afs_put_vlserverlist(cell->net, old); out_wake: smp_store_release(&cell->dns_lookup_count, cell->dns_lookup_count + 1); /* vs source/status */ wake_up_var(&cell->dns_lookup_count); _leave(" = %d", ret); return ret; } /* * Destroy a cell record */ static void afs_cell_destroy(struct rcu_head *rcu) { struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu); struct afs_net *net = cell->net; int r; _enter("%p{%s}", cell, cell->name); r = refcount_read(&cell->ref); ASSERTCMP(r, ==, 0); trace_afs_cell(cell->debug_id, r, atomic_read(&cell->active), afs_cell_trace_free); afs_put_vlserverlist(net, rcu_access_pointer(cell->vl_servers)); afs_unuse_cell(net, cell->alias_of, afs_cell_trace_unuse_alias); key_put(cell->anonymous_key); kfree(cell->name); kfree(cell); afs_dec_cells_outstanding(net); _leave(" [destroyed]"); } /* * Queue the cell manager. */ static void afs_queue_cell_manager(struct afs_net *net) { int outstanding = atomic_inc_return(&net->cells_outstanding); _enter("%d", outstanding); if (!queue_work(afs_wq, &net->cells_manager)) afs_dec_cells_outstanding(net); } /* * Cell management timer. We have an increment on cells_outstanding that we * need to pass along to the work item. */ void afs_cells_timer(struct timer_list *timer) { struct afs_net *net = container_of(timer, struct afs_net, cells_timer); _enter(""); if (!queue_work(afs_wq, &net->cells_manager)) afs_dec_cells_outstanding(net); } /* * Get a reference on a cell record. */ struct afs_cell *afs_get_cell(struct afs_cell *cell, enum afs_cell_trace reason) { int r; __refcount_inc(&cell->ref, &r); trace_afs_cell(cell->debug_id, r + 1, atomic_read(&cell->active), reason); return cell; } /* * Drop a reference on a cell record. */ void afs_put_cell(struct afs_cell *cell, enum afs_cell_trace reason) { if (cell) { unsigned int debug_id = cell->debug_id; unsigned int a; bool zero; int r; a = atomic_read(&cell->active); zero = __refcount_dec_and_test(&cell->ref, &r); trace_afs_cell(debug_id, r - 1, a, reason); if (zero) { a = atomic_read(&cell->active); WARN(a != 0, "Cell active count %u > 0\n", a); call_rcu(&cell->rcu, afs_cell_destroy); } } } /* * Note a cell becoming more active. */ struct afs_cell *afs_use_cell(struct afs_cell *cell, enum afs_cell_trace reason) { int r, a; r = refcount_read(&cell->ref); WARN_ON(r == 0); a = atomic_inc_return(&cell->active); trace_afs_cell(cell->debug_id, r, a, reason); return cell; } /* * Record a cell becoming less active. When the active counter reaches 1, it * is scheduled for destruction, but may get reactivated. */ void afs_unuse_cell(struct afs_net *net, struct afs_cell *cell, enum afs_cell_trace reason) { unsigned int debug_id; time64_t now, expire_delay; int r, a; if (!cell) return; _enter("%s", cell->name); now = ktime_get_real_seconds(); cell->last_inactive = now; expire_delay = 0; if (cell->vl_servers->nr_servers) expire_delay = afs_cell_gc_delay; debug_id = cell->debug_id; r = refcount_read(&cell->ref); a = atomic_dec_return(&cell->active); trace_afs_cell(debug_id, r, a, reason); WARN_ON(a == 0); if (a == 1) /* 'cell' may now be garbage collected. */ afs_set_cell_timer(net, expire_delay); } /* * Note that a cell has been seen. */ void afs_see_cell(struct afs_cell *cell, enum afs_cell_trace reason) { int r, a; r = refcount_read(&cell->ref); a = atomic_read(&cell->active); trace_afs_cell(cell->debug_id, r, a, reason); } /* * Queue a cell for management, giving the workqueue a ref to hold. */ void afs_queue_cell(struct afs_cell *cell, enum afs_cell_trace reason) { afs_get_cell(cell, reason); if (!queue_work(afs_wq, &cell->manager)) afs_put_cell(cell, afs_cell_trace_put_queue_fail); } /* * Allocate a key to use as a placeholder for anonymous user security. */ static int afs_alloc_anon_key(struct afs_cell *cell) { struct key *key; char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp; /* Create a key to represent an anonymous user. */ memcpy(keyname, "afs@", 4); dp = keyname + 4; cp = cell->name; do { *dp++ = tolower(*cp); } while (*cp++); key = rxrpc_get_null_key(keyname); if (IS_ERR(key)) return PTR_ERR(key); cell->anonymous_key = key; _debug("anon key %p{%x}", cell->anonymous_key, key_serial(cell->anonymous_key)); return 0; } /* * Activate a cell. */ static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell) { struct hlist_node **p; struct afs_cell *pcell; int ret; if (!cell->anonymous_key) { ret = afs_alloc_anon_key(cell); if (ret < 0) return ret; } ret = afs_proc_cell_setup(cell); if (ret < 0) return ret; mutex_lock(&net->proc_cells_lock); for (p = &net->proc_cells.first; *p; p = &(*p)->next) { pcell = hlist_entry(*p, struct afs_cell, proc_link); if (strcmp(cell->name, pcell->name) < 0) break; } cell->proc_link.pprev = p; cell->proc_link.next = *p; rcu_assign_pointer(*p, &cell->proc_link.next); if (cell->proc_link.next) cell->proc_link.next->pprev = &cell->proc_link.next; afs_dynroot_mkdir(net, cell); mutex_unlock(&net->proc_cells_lock); return 0; } /* * Deactivate a cell. */ static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell) { _enter("%s", cell->name); afs_proc_cell_remove(cell); mutex_lock(&net->proc_cells_lock); hlist_del_rcu(&cell->proc_link); afs_dynroot_rmdir(net, cell); mutex_unlock(&net->proc_cells_lock); _leave(""); } /* * Manage a cell record, initialising and destroying it, maintaining its DNS * records. */ static void afs_manage_cell(struct afs_cell *cell) { struct afs_net *net = cell->net; int ret, active; _enter("%s", cell->name); again: _debug("state %u", cell->state); switch (cell->state) { case AFS_CELL_INACTIVE: case AFS_CELL_FAILED: down_write(&net->cells_lock); active = 1; if (atomic_try_cmpxchg_relaxed(&cell->active, &active, 0)) { rb_erase(&cell->net_node, &net->cells); trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), 0, afs_cell_trace_unuse_delete); smp_store_release(&cell->state, AFS_CELL_REMOVED); } up_write(&net->cells_lock); if (cell->state == AFS_CELL_REMOVED) { wake_up_var(&cell->state); goto final_destruction; } if (cell->state == AFS_CELL_FAILED) goto done; smp_store_release(&cell->state, AFS_CELL_UNSET); wake_up_var(&cell->state); goto again; case AFS_CELL_UNSET: smp_store_release(&cell->state, AFS_CELL_ACTIVATING); wake_up_var(&cell->state); goto again; case AFS_CELL_ACTIVATING: ret = afs_activate_cell(net, cell); if (ret < 0) goto activation_failed; smp_store_release(&cell->state, AFS_CELL_ACTIVE); wake_up_var(&cell->state); goto again; case AFS_CELL_ACTIVE: if (atomic_read(&cell->active) > 1) { if (test_and_clear_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) { ret = afs_update_cell(cell); if (ret < 0) cell->error = ret; } goto done; } smp_store_release(&cell->state, AFS_CELL_DEACTIVATING); wake_up_var(&cell->state); goto again; case AFS_CELL_DEACTIVATING: if (atomic_read(&cell->active) > 1) goto reverse_deactivation; afs_deactivate_cell(net, cell); smp_store_release(&cell->state, AFS_CELL_INACTIVE); wake_up_var(&cell->state); goto again; case AFS_CELL_REMOVED: goto done; default: break; } _debug("bad state %u", cell->state); BUG(); /* Unhandled state */ activation_failed: cell->error = ret; afs_deactivate_cell(net, cell); smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */ wake_up_var(&cell->state); goto again; reverse_deactivation: smp_store_release(&cell->state, AFS_CELL_ACTIVE); wake_up_var(&cell->state); _leave(" [deact->act]"); return; done: _leave(" [done %u]", cell->state); return; final_destruction: /* The root volume is pinning the cell */ afs_put_volume(cell->root_volume, afs_volume_trace_put_cell_root); cell->root_volume = NULL; afs_put_cell(cell, afs_cell_trace_put_destroy); } static void afs_manage_cell_work(struct work_struct *work) { struct afs_cell *cell = container_of(work, struct afs_cell, manager); afs_manage_cell(cell); afs_put_cell(cell, afs_cell_trace_put_queue_work); } /* * Manage the records of cells known to a network namespace. This includes * updating the DNS records and garbage collecting unused cells that were * automatically added. * * Note that constructed cell records may only be removed from net->cells by * this work item, so it is safe for this work item to stash a cursor pointing * into the tree and then return to caller (provided it skips cells that are * still under construction). * * Note also that we were given an increment on net->cells_outstanding by * whoever queued us that we need to deal with before returning. */ void afs_manage_cells(struct work_struct *work) { struct afs_net *net = container_of(work, struct afs_net, cells_manager); struct rb_node *cursor; time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX; bool purging = !net->live; _enter(""); /* Trawl the cell database looking for cells that have expired from * lack of use and cells whose DNS results have expired and dispatch * their managers. */ down_read(&net->cells_lock); for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) { struct afs_cell *cell = rb_entry(cursor, struct afs_cell, net_node); unsigned active; bool sched_cell = false; active = atomic_read(&cell->active); trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), active, afs_cell_trace_manage); ASSERTCMP(active, >=, 1); if (purging) { if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags)) { active = atomic_dec_return(&cell->active); trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), active, afs_cell_trace_unuse_pin); } } if (active == 1) { struct afs_vlserver_list *vllist; time64_t expire_at = cell->last_inactive; read_lock(&cell->vl_servers_lock); vllist = rcu_dereference_protected( cell->vl_servers, lockdep_is_held(&cell->vl_servers_lock)); if (vllist->nr_servers > 0) expire_at += afs_cell_gc_delay; read_unlock(&cell->vl_servers_lock); if (purging || expire_at <= now) sched_cell = true; else if (expire_at < next_manage) next_manage = expire_at; } if (!purging) { if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) sched_cell = true; } if (sched_cell) afs_queue_cell(cell, afs_cell_trace_get_queue_manage); } up_read(&net->cells_lock); /* Update the timer on the way out. We have to pass an increment on * cells_outstanding in the namespace that we are in to the timer or * the work scheduler. */ if (!purging && next_manage < TIME64_MAX) { now = ktime_get_real_seconds(); if (next_manage - now <= 0) { if (queue_work(afs_wq, &net->cells_manager)) atomic_inc(&net->cells_outstanding); } else { afs_set_cell_timer(net, next_manage - now); } } afs_dec_cells_outstanding(net); _leave(" [%d]", atomic_read(&net->cells_outstanding)); } /* * Purge in-memory cell database. */ void afs_cell_purge(struct afs_net *net) { struct afs_cell *ws; _enter(""); down_write(&net->cells_lock); ws = net->ws_cell; net->ws_cell = NULL; up_write(&net->cells_lock); afs_unuse_cell(net, ws, afs_cell_trace_unuse_ws); _debug("del timer"); if (del_timer_sync(&net->cells_timer)) atomic_dec(&net->cells_outstanding); _debug("kick mgr"); afs_queue_cell_manager(net); _debug("wait"); wait_var_event(&net->cells_outstanding, !atomic_read(&net->cells_outstanding)); _leave(""); }
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