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-rw-r--r--fs/afs/cell.c149
-rw-r--r--fs/afs/dynroot.c2
-rw-r--r--fs/afs/internal.h8
-rw-r--r--fs/afs/mntpt.c4
-rw-r--r--fs/afs/proc.c23
-rw-r--r--fs/afs/super.c12
-rw-r--r--fs/afs/vl_alias.c8
-rw-r--r--fs/afs/vl_rotate.c2
-rw-r--r--fs/afs/volume.c4
9 files changed, 136 insertions, 76 deletions
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 5da83e84952a..c906000b0ff8 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -19,7 +19,7 @@ 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 void afs_manage_cell(struct work_struct *);
+static void afs_manage_cell_work(struct work_struct *);
static void afs_dec_cells_outstanding(struct afs_net *net)
{
@@ -62,8 +62,7 @@ static struct afs_cell *afs_find_cell_locked(struct afs_net *net,
cell = net->ws_cell;
if (!cell)
return ERR_PTR(-EDESTADDRREQ);
- afs_get_cell(cell);
- return cell;
+ goto found;
}
p = net->cells.rb_node;
@@ -85,12 +84,12 @@ static struct afs_cell *afs_find_cell_locked(struct afs_net *net,
return ERR_PTR(-ENOENT);
found:
- if (!atomic_inc_not_zero(&cell->usage))
- return ERR_PTR(-ENOENT);
-
- return cell;
+ return afs_use_cell(cell);
}
+/*
+ * 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)
{
@@ -153,8 +152,9 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
cell->name[i] = tolower(name[i]);
cell->name[i] = 0;
- atomic_set(&cell->usage, 2);
- INIT_WORK(&cell->manager, afs_manage_cell);
+ atomic_set(&cell->ref, 1);
+ atomic_set(&cell->active, 0);
+ INIT_WORK(&cell->manager, afs_manage_cell_work);
cell->volumes = RB_ROOT;
INIT_HLIST_HEAD(&cell->proc_volumes);
seqlock_init(&cell->volume_lock);
@@ -193,6 +193,7 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
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);
_leave(" = %p", cell);
return cell;
@@ -275,12 +276,12 @@ struct afs_cell *afs_lookup_cell(struct afs_net *net,
cell = candidate;
candidate = NULL;
+ atomic_set(&cell->active, 2);
rb_link_node_rcu(&cell->net_node, parent, pp);
rb_insert_color(&cell->net_node, &net->cells);
- atomic_inc(&net->cells_outstanding);
up_write(&net->cells_lock);
- queue_work(afs_wq, &cell->manager);
+ afs_queue_cell(cell);
wait_for_cell:
_debug("wait_for_cell");
@@ -305,16 +306,17 @@ cell_already_exists:
if (excl) {
ret = -EEXIST;
} else {
- afs_get_cell(cursor);
+ afs_use_cell(cursor);
ret = 0;
}
up_write(&net->cells_lock);
- kfree(candidate);
+ if (candidate)
+ afs_put_cell(candidate);
if (ret == 0)
goto wait_for_cell;
goto error_noput;
error:
- afs_put_cell(net, cell);
+ afs_unuse_cell(net, cell);
error_noput:
_leave(" = %d [error]", ret);
return ERR_PTR(ret);
@@ -359,7 +361,7 @@ int afs_cell_init(struct afs_net *net, const char *rootcell)
}
if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags))
- afs_get_cell(new_root);
+ afs_use_cell(new_root);
/* install the new cell */
down_write(&net->cells_lock);
@@ -367,7 +369,7 @@ int afs_cell_init(struct afs_net *net, const char *rootcell)
net->ws_cell = new_root;
up_write(&net->cells_lock);
- afs_put_cell(net, old_root);
+ afs_unuse_cell(net, old_root);
_leave(" = 0");
return 0;
}
@@ -473,18 +475,21 @@ out_wake:
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 u;
_enter("%p{%s}", cell, cell->name);
- ASSERTCMP(atomic_read(&cell->usage), ==, 0);
+ u = atomic_read(&cell->ref);
+ ASSERTCMP(u, ==, 0);
- afs_put_volume(cell->net, cell->root_volume, afs_volume_trace_put_cell_root);
- afs_put_vlserverlist(cell->net, rcu_access_pointer(cell->vl_servers));
- afs_put_cell(cell->net, cell->alias_of);
+ afs_put_vlserverlist(net, rcu_access_pointer(cell->vl_servers));
+ afs_unuse_cell(net, cell->alias_of);
key_put(cell->anonymous_key);
kfree(cell->name);
kfree(cell);
+ afs_dec_cells_outstanding(net);
_leave(" [destroyed]");
}
@@ -519,16 +524,50 @@ void afs_cells_timer(struct timer_list *timer)
*/
struct afs_cell *afs_get_cell(struct afs_cell *cell)
{
- atomic_inc(&cell->usage);
+ if (atomic_read(&cell->ref) <= 0)
+ BUG();
+
+ atomic_inc(&cell->ref);
return cell;
}
/*
* Drop a reference on a cell record.
*/
-void afs_put_cell(struct afs_net *net, struct afs_cell *cell)
+void afs_put_cell(struct afs_cell *cell)
+{
+ if (cell) {
+ unsigned int u, a;
+
+ u = atomic_dec_return(&cell->ref);
+ if (u == 0) {
+ 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)
+{
+ if (atomic_read(&cell->ref) <= 0)
+ BUG();
+
+ atomic_inc(&cell->active);
+ 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)
{
time64_t now, expire_delay;
+ int a;
if (!cell)
return;
@@ -541,11 +580,21 @@ void afs_put_cell(struct afs_net *net, struct afs_cell *cell)
if (cell->vl_servers->nr_servers)
expire_delay = afs_cell_gc_delay;
- if (atomic_dec_return(&cell->usage) > 1)
- return;
+ a = atomic_dec_return(&cell->active);
+ WARN_ON(a == 0);
+ if (a == 1)
+ /* 'cell' may now be garbage collected. */
+ afs_set_cell_timer(net, expire_delay);
+}
- /* 'cell' may now be garbage collected. */
- afs_set_cell_timer(net, expire_delay);
+/*
+ * Queue a cell for management, giving the workqueue a ref to hold.
+ */
+void afs_queue_cell(struct afs_cell *cell)
+{
+ afs_get_cell(cell);
+ if (!queue_work(afs_wq, &cell->manager))
+ afs_put_cell(cell);
}
/*
@@ -645,12 +694,11 @@ static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell)
* Manage a cell record, initialising and destroying it, maintaining its DNS
* records.
*/
-static void afs_manage_cell(struct work_struct *work)
+static void afs_manage_cell(struct afs_cell *cell)
{
- struct afs_cell *cell = container_of(work, struct afs_cell, manager);
struct afs_net *net = cell->net;
bool deleted;
- int ret, usage;
+ int ret, active;
_enter("%s", cell->name);
@@ -660,10 +708,11 @@ again:
case AFS_CELL_INACTIVE:
case AFS_CELL_FAILED:
down_write(&net->cells_lock);
- usage = 1;
- deleted = atomic_try_cmpxchg_relaxed(&cell->usage, &usage, 0);
- if (deleted)
+ active = 1;
+ deleted = atomic_try_cmpxchg_relaxed(&cell->active, &active, 0);
+ if (deleted) {
rb_erase(&cell->net_node, &net->cells);
+ }
up_write(&net->cells_lock);
if (deleted)
goto final_destruction;
@@ -688,7 +737,7 @@ again:
goto again;
case AFS_CELL_ACTIVE:
- if (atomic_read(&cell->usage) > 1) {
+ 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)
@@ -701,7 +750,7 @@ again:
goto again;
case AFS_CELL_DEACTIVATING:
- if (atomic_read(&cell->usage) > 1)
+ if (atomic_read(&cell->active) > 1)
goto reverse_deactivation;
afs_deactivate_cell(net, cell);
smp_store_release(&cell->state, AFS_CELL_INACTIVE);
@@ -733,9 +782,18 @@ done:
return;
final_destruction:
- call_rcu(&cell->rcu, afs_cell_destroy);
- afs_dec_cells_outstanding(net);
- _leave(" [destruct %d]", atomic_read(&net->cells_outstanding));
+ /* The root volume is pinning the cell */
+ afs_put_volume(cell->net, cell->root_volume, afs_volume_trace_put_cell_root);
+ cell->root_volume = NULL;
+ afs_put_cell(cell);
+}
+
+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);
}
/*
@@ -769,21 +827,20 @@ void afs_manage_cells(struct work_struct *work)
for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) {
struct afs_cell *cell =
rb_entry(cursor, struct afs_cell, net_node);
- unsigned usage;
+ unsigned active;
bool sched_cell = false;
- usage = atomic_read(&cell->usage);
- _debug("manage %s %u", cell->name, usage);
+ active = atomic_read(&cell->active);
+ _debug("manage %s %u %u", cell->name, atomic_read(&cell->ref), active);
- ASSERTCMP(usage, >=, 1);
+ ASSERTCMP(active, >=, 1);
if (purging) {
if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags))
- usage = atomic_dec_return(&cell->usage);
- ASSERTCMP(usage, ==, 1);
+ atomic_dec(&cell->active);
}
- if (usage == 1) {
+ if (active == 1) {
struct afs_vlserver_list *vllist;
time64_t expire_at = cell->last_inactive;
@@ -806,7 +863,7 @@ void afs_manage_cells(struct work_struct *work)
}
if (sched_cell)
- queue_work(afs_wq, &cell->manager);
+ afs_queue_cell(cell);
}
up_read(&net->cells_lock);
@@ -843,7 +900,7 @@ void afs_cell_purge(struct afs_net *net)
ws = net->ws_cell;
net->ws_cell = NULL;
up_write(&net->cells_lock);
- afs_put_cell(net, ws);
+ afs_unuse_cell(net, ws);
_debug("del timer");
if (del_timer_sync(&net->cells_timer))
diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index 5b8de4fee6cd..da32797dd425 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -125,7 +125,7 @@ static int afs_probe_cell_name(struct dentry *dentry)
cell = afs_find_cell(net, name, len);
if (!IS_ERR(cell)) {
- afs_put_cell(net, cell);
+ afs_unuse_cell(net, cell);
return 0;
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 257c0f07742f..0363511290c8 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -363,7 +363,8 @@ struct afs_cell {
#endif
time64_t dns_expiry; /* Time AFSDB/SRV record expires */
time64_t last_inactive; /* Time of last drop of usage count */
- atomic_t usage;
+ atomic_t ref; /* Struct refcount */
+ atomic_t active; /* Active usage counter */
unsigned long flags;
#define AFS_CELL_FL_NO_GC 0 /* The cell was added manually, don't auto-gc */
#define AFS_CELL_FL_DO_LOOKUP 1 /* DNS lookup requested */
@@ -920,8 +921,11 @@ extern int afs_cell_init(struct afs_net *, const char *);
extern struct afs_cell *afs_find_cell(struct afs_net *, const char *, unsigned);
extern struct afs_cell *afs_lookup_cell(struct afs_net *, const char *, unsigned,
const char *, bool);
+extern struct afs_cell *afs_use_cell(struct afs_cell *);
+extern void afs_unuse_cell(struct afs_net *, struct afs_cell *);
extern struct afs_cell *afs_get_cell(struct afs_cell *);
-extern void afs_put_cell(struct afs_net *, struct afs_cell *);
+extern void afs_put_cell(struct afs_cell *);
+extern void afs_queue_cell(struct afs_cell *);
extern void afs_manage_cells(struct work_struct *);
extern void afs_cells_timer(struct timer_list *);
extern void __net_exit afs_cell_purge(struct afs_net *);
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 79bc5f1338ed..c69a0282960c 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -88,7 +88,7 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt)
ctx->force = true;
}
if (ctx->cell) {
- afs_put_cell(ctx->net, ctx->cell);
+ afs_unuse_cell(ctx->net, ctx->cell);
ctx->cell = NULL;
}
if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) {
@@ -124,7 +124,7 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt)
char *buf;
if (src_as->cell)
- ctx->cell = afs_get_cell(src_as->cell);
+ ctx->cell = afs_use_cell(src_as->cell);
if (size < 2 || size > PAGE_SIZE - 1)
return -EINVAL;
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index e8babb62ed44..76fbe0560cfb 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -38,7 +38,7 @@ static int afs_proc_cells_show(struct seq_file *m, void *v)
if (v == SEQ_START_TOKEN) {
/* display header on line 1 */
- seq_puts(m, "USE TTL SV ST NAME\n");
+ seq_puts(m, "USE ACT TTL SV ST NAME\n");
return 0;
}
@@ -46,10 +46,11 @@ static int afs_proc_cells_show(struct seq_file *m, void *v)
vllist = rcu_dereference(cell->vl_servers);
/* display one cell per line on subsequent lines */
- seq_printf(m, "%3u %6lld %2u %2u %s\n",
- atomic_read(&cell->usage),
+ seq_printf(m, "%3u %3u %6lld %2u %2u %s\n",
+ atomic_read(&cell->ref),
+ atomic_read(&cell->active),
cell->dns_expiry - ktime_get_real_seconds(),
- vllist->nr_servers,
+ vllist ? vllist->nr_servers : 0,
cell->state,
cell->name);
return 0;
@@ -128,7 +129,7 @@ static int afs_proc_cells_write(struct file *file, char *buf, size_t size)
}
if (test_and_set_bit(AFS_CELL_FL_NO_GC, &cell->flags))
- afs_put_cell(net, cell);
+ afs_unuse_cell(net, cell);
} else {
goto inval;
}
@@ -154,13 +155,11 @@ static int afs_proc_rootcell_show(struct seq_file *m, void *v)
struct afs_net *net;
net = afs_seq2net_single(m);
- if (rcu_access_pointer(net->ws_cell)) {
- rcu_read_lock();
- cell = rcu_dereference(net->ws_cell);
- if (cell)
- seq_printf(m, "%s\n", cell->name);
- rcu_read_unlock();
- }
+ down_read(&net->cells_lock);
+ cell = net->ws_cell;
+ if (cell)
+ seq_printf(m, "%s\n", cell->name);
+ up_read(&net->cells_lock);
return 0;
}
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 0be99016ecfb..e72c223f831d 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -294,7 +294,7 @@ static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
cellnamesz, cellnamesz, cellname ?: "");
return PTR_ERR(cell);
}
- afs_put_cell(ctx->net, ctx->cell);
+ afs_unuse_cell(ctx->net, ctx->cell);
ctx->cell = cell;
}
@@ -389,8 +389,8 @@ static int afs_validate_fc(struct fs_context *fc)
_debug("switch to alias");
key_put(ctx->key);
ctx->key = NULL;
- cell = afs_get_cell(ctx->cell->alias_of);
- afs_put_cell(ctx->net, ctx->cell);
+ cell = afs_use_cell(ctx->cell->alias_of);
+ afs_unuse_cell(ctx->net, ctx->cell);
ctx->cell = cell;
goto reget_key;
}
@@ -508,7 +508,7 @@ static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
if (ctx->dyn_root) {
as->dyn_root = true;
} else {
- as->cell = afs_get_cell(ctx->cell);
+ as->cell = afs_use_cell(ctx->cell);
as->volume = afs_get_volume(ctx->volume,
afs_volume_trace_get_alloc_sbi);
}
@@ -521,7 +521,7 @@ static void afs_destroy_sbi(struct afs_super_info *as)
if (as) {
struct afs_net *net = afs_net(as->net_ns);
afs_put_volume(net, as->volume, afs_volume_trace_put_destroy_sbi);
- afs_put_cell(net, as->cell);
+ afs_unuse_cell(net, as->cell);
put_net(as->net_ns);
kfree(as);
}
@@ -607,7 +607,7 @@ static void afs_free_fc(struct fs_context *fc)
afs_destroy_sbi(fc->s_fs_info);
afs_put_volume(ctx->net, ctx->volume, afs_volume_trace_put_free_fc);
- afs_put_cell(ctx->net, ctx->cell);
+ afs_unuse_cell(ctx->net, ctx->cell);
key_put(ctx->key);
kfree(ctx);
}
diff --git a/fs/afs/vl_alias.c b/fs/afs/vl_alias.c
index 5082ef04e99c..ddb4cb67d0fd 100644
--- a/fs/afs/vl_alias.c
+++ b/fs/afs/vl_alias.c
@@ -177,7 +177,7 @@ static int afs_compare_cell_roots(struct afs_cell *cell)
is_alias:
rcu_read_unlock();
- cell->alias_of = afs_get_cell(p);
+ cell->alias_of = afs_use_cell(p);
return 1;
}
@@ -247,18 +247,18 @@ static int afs_query_for_alias(struct afs_cell *cell, struct key *key)
continue;
if (p->root_volume)
continue; /* Ignore cells that have a root.cell volume. */
- afs_get_cell(p);
+ afs_use_cell(p);
mutex_unlock(&cell->net->proc_cells_lock);
if (afs_query_for_alias_one(cell, key, p) != 0)
goto is_alias;
if (mutex_lock_interruptible(&cell->net->proc_cells_lock) < 0) {
- afs_put_cell(cell->net, p);
+ afs_unuse_cell(cell->net, p);
return -ERESTARTSYS;
}
- afs_put_cell(cell->net, p);
+ afs_unuse_cell(cell->net, p);
}
mutex_unlock(&cell->net->proc_cells_lock);
diff --git a/fs/afs/vl_rotate.c b/fs/afs/vl_rotate.c
index c0458c903b31..da3b072d4d63 100644
--- a/fs/afs/vl_rotate.c
+++ b/fs/afs/vl_rotate.c
@@ -45,7 +45,7 @@ static bool afs_start_vl_iteration(struct afs_vl_cursor *vc)
cell->dns_expiry <= ktime_get_real_seconds()) {
dns_lookup_count = smp_load_acquire(&cell->dns_lookup_count);
set_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags);
- queue_work(afs_wq, &cell->manager);
+ afs_queue_cell(cell);
if (cell->dns_source == DNS_RECORD_UNAVAILABLE) {
if (wait_var_event_interruptible(
diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 9bc0509e3634..a838030e9563 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -106,7 +106,7 @@ static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
return volume;
error_1:
- afs_put_cell(params->net, volume->cell);
+ afs_put_cell(volume->cell);
kfree(volume);
error_0:
return ERR_PTR(ret);
@@ -228,7 +228,7 @@ static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume)
afs_remove_volume_from_cell(volume);
afs_put_serverlist(net, rcu_access_pointer(volume->servers));
- afs_put_cell(net, volume->cell);
+ afs_put_cell(volume->cell);
trace_afs_volume(volume->vid, atomic_read(&volume->usage),
afs_volume_trace_free);
kfree_rcu(volume, rcu);
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 03:19:28 +0000