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-rw-r--r--fs/afs/cell.c169
-rw-r--r--fs/afs/internal.h10
-rw-r--r--fs/afs/vl_rotate.c26
3 files changed, 130 insertions, 75 deletions
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 47f96be05163..9c3b07ba2222 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -152,8 +152,6 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
atomic_set(&cell->usage, 2);
INIT_WORK(&cell->manager, afs_manage_cell);
- cell->flags = ((1 << AFS_CELL_FL_NOT_READY) |
- (1 << AFS_CELL_FL_NO_LOOKUP_YET));
INIT_LIST_HEAD(&cell->proc_volumes);
rwlock_init(&cell->proc_lock);
rwlock_init(&cell->vl_servers_lock);
@@ -170,17 +168,25 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net,
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 */
+
_leave(" = %p", cell);
return cell;
@@ -212,6 +218,7 @@ struct afs_cell *afs_lookup_cell(struct afs_net *net,
{
struct afs_cell *cell, *candidate, *cursor;
struct rb_node *parent, **pp;
+ enum afs_cell_state state;
int ret, n;
_enter("%s,%s", name, vllist);
@@ -271,18 +278,16 @@ struct afs_cell *afs_lookup_cell(struct afs_net *net,
wait_for_cell:
_debug("wait_for_cell");
- ret = wait_on_bit(&cell->flags, AFS_CELL_FL_NOT_READY, TASK_INTERRUPTIBLE);
- smp_rmb();
-
- switch (READ_ONCE(cell->state)) {
- case AFS_CELL_FAILED:
+ wait_var_event(&cell->state,
+ ({
+ state = smp_load_acquire(&cell->state); /* vs error */
+ state == AFS_CELL_ACTIVE || state == AFS_CELL_FAILED;
+ }));
+
+ /* Check the state obtained from the wait check. */
+ if (state == AFS_CELL_FAILED) {
ret = cell->error;
goto error;
- default:
- _debug("weird %u %d", cell->state, cell->error);
- goto error;
- case AFS_CELL_ACTIVE:
- break;
}
_leave(" = %p [cell]", cell);
@@ -364,16 +369,46 @@ int afs_cell_init(struct afs_net *net, const char *rootcell)
/*
* Update a cell's VL server address list from the DNS.
*/
-static void afs_update_cell(struct afs_cell *cell)
+static int afs_update_cell(struct afs_cell *cell)
{
- struct afs_vlserver_list *vllist, *old;
+ 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;
+
+ ret = -ENOMEM;
+ vllist = afs_alloc_vlserver_list(0);
+ if (!vllist)
+ 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)
@@ -383,46 +418,47 @@ static void afs_update_cell(struct afs_cell *cell)
else if (expiry > now + max_ttl)
expiry = now + max_ttl;
- if (IS_ERR(vllist)) {
- switch (PTR_ERR(vllist)) {
- case -ENODATA:
- case -EDESTADDRREQ:
+ _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.
*/
- set_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
- clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
cell->dns_expiry = expiry;
break;
- case -EAGAIN:
- case -ECONNREFUSED:
+ case DNS_LOOKUP_BAD:
+ case DNS_LOOKUP_GOT_LOCAL_FAILURE:
+ case DNS_LOOKUP_GOT_TEMP_FAILURE:
+ case DNS_LOOKUP_GOT_NS_FAILURE:
default:
- set_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
cell->dns_expiry = now + 10;
break;
}
-
- cell->error = -EDESTADDRREQ;
} else {
- clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
- clear_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
-
- write_lock(&cell->vl_servers_lock);
- old = rcu_dereference_protected(cell->vl_servers, true);
- rcu_assign_pointer(cell->vl_servers, vllist);
cell->dns_expiry = expiry;
- write_unlock(&cell->vl_servers_lock);
-
- afs_put_vlserverlist(cell->net, old);
}
- if (test_and_clear_bit(AFS_CELL_FL_NO_LOOKUP_YET, &cell->flags))
- wake_up_bit(&cell->flags, AFS_CELL_FL_NO_LOOKUP_YET);
+ /* 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);
- now = ktime_get_real_seconds();
- afs_set_cell_timer(cell->net, cell->dns_expiry - now);
- _leave("");
+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;
}
/*
@@ -493,8 +529,7 @@ void afs_put_cell(struct afs_net *net, struct afs_cell *cell)
now = ktime_get_real_seconds();
cell->last_inactive = now;
expire_delay = 0;
- if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
- !test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
+ if (cell->vl_servers->nr_servers)
expire_delay = afs_cell_gc_delay;
if (atomic_dec_return(&cell->usage) > 1)
@@ -625,11 +660,13 @@ again:
goto final_destruction;
if (cell->state == AFS_CELL_FAILED)
goto done;
- cell->state = AFS_CELL_UNSET;
+ smp_store_release(&cell->state, AFS_CELL_UNSET);
+ wake_up_var(&cell->state);
goto again;
case AFS_CELL_UNSET:
- cell->state = AFS_CELL_ACTIVATING;
+ smp_store_release(&cell->state, AFS_CELL_ACTIVATING);
+ wake_up_var(&cell->state);
goto again;
case AFS_CELL_ACTIVATING:
@@ -637,28 +674,29 @@ again:
if (ret < 0)
goto activation_failed;
- cell->state = AFS_CELL_ACTIVE;
- smp_wmb();
- clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
- wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+ smp_store_release(&cell->state, AFS_CELL_ACTIVE);
+ wake_up_var(&cell->state);
goto again;
case AFS_CELL_ACTIVE:
if (atomic_read(&cell->usage) > 1) {
- time64_t now = ktime_get_real_seconds();
- if (cell->dns_expiry <= now && net->live)
- afs_update_cell(cell);
+ 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;
}
- cell->state = AFS_CELL_DEACTIVATING;
+ smp_store_release(&cell->state, AFS_CELL_DEACTIVATING);
+ wake_up_var(&cell->state);
goto again;
case AFS_CELL_DEACTIVATING:
- set_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
if (atomic_read(&cell->usage) > 1)
goto reverse_deactivation;
afs_deactivate_cell(net, cell);
- cell->state = AFS_CELL_INACTIVE;
+ smp_store_release(&cell->state, AFS_CELL_INACTIVE);
+ wake_up_var(&cell->state);
goto again;
default:
@@ -671,17 +709,13 @@ activation_failed:
cell->error = ret;
afs_deactivate_cell(net, cell);
- cell->state = AFS_CELL_FAILED;
- smp_wmb();
- if (test_and_clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags))
- wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+ smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */
+ wake_up_var(&cell->state);
goto again;
reverse_deactivation:
- cell->state = AFS_CELL_ACTIVE;
- smp_wmb();
- clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
- wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
+ smp_store_release(&cell->state, AFS_CELL_ACTIVE);
+ wake_up_var(&cell->state);
_leave(" [deact->act]");
return;
@@ -741,11 +775,16 @@ void afs_manage_cells(struct work_struct *work)
}
if (usage == 1) {
+ struct afs_vlserver_list *vllist;
time64_t expire_at = cell->last_inactive;
- if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
- !test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
+ 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)
@@ -753,10 +792,8 @@ void afs_manage_cells(struct work_struct *work)
}
if (!purging) {
- if (cell->dns_expiry <= now)
+ if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags))
sched_cell = true;
- else if (cell->dns_expiry <= next_manage)
- next_manage = cell->dns_expiry;
}
if (sched_cell)
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 74ee0f8ef8dd..50d925f0a556 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -367,13 +367,13 @@ struct afs_cell {
time64_t last_inactive; /* Time of last drop of usage count */
atomic_t usage;
unsigned long flags;
-#define AFS_CELL_FL_NOT_READY 0 /* The cell record is not ready for use */
-#define AFS_CELL_FL_NO_GC 1 /* The cell was added manually, don't auto-gc */
-#define AFS_CELL_FL_NOT_FOUND 2 /* Permanent DNS error */
-#define AFS_CELL_FL_DNS_FAIL 3 /* Failed to access DNS */
-#define AFS_CELL_FL_NO_LOOKUP_YET 4 /* Not completed first DNS lookup yet */
+#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 */
enum afs_cell_state state;
short error;
+ enum dns_record_source dns_source:8; /* Latest source of data from lookup */
+ enum dns_lookup_status dns_status:8; /* Latest status of data from lookup */
+ unsigned int dns_lookup_count; /* Counter of DNS lookups */
/* Active fileserver interaction state. */
struct list_head proc_volumes; /* procfs volume list */
diff --git a/fs/afs/vl_rotate.c b/fs/afs/vl_rotate.c
index 65629d73ad9d..3f845489a9f0 100644
--- a/fs/afs/vl_rotate.c
+++ b/fs/afs/vl_rotate.c
@@ -43,11 +43,29 @@ bool afs_begin_vlserver_operation(struct afs_vl_cursor *vc, struct afs_cell *cel
static bool afs_start_vl_iteration(struct afs_vl_cursor *vc)
{
struct afs_cell *cell = vc->cell;
+ unsigned int dns_lookup_count;
+
+ if (cell->dns_source == DNS_RECORD_UNAVAILABLE ||
+ 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);
+
+ if (cell->dns_source == DNS_RECORD_UNAVAILABLE) {
+ if (wait_var_event_interruptible(
+ &cell->dns_lookup_count,
+ smp_load_acquire(&cell->dns_lookup_count)
+ != dns_lookup_count) < 0) {
+ vc->error = -ERESTARTSYS;
+ return false;
+ }
+ }
- if (wait_on_bit(&cell->flags, AFS_CELL_FL_NO_LOOKUP_YET,
- TASK_INTERRUPTIBLE)) {
- vc->error = -ERESTARTSYS;
- return false;
+ /* Status load is ordered after lookup counter load */
+ if (cell->dns_source == DNS_RECORD_UNAVAILABLE) {
+ vc->error = -EDESTADDRREQ;
+ return false;
+ }
}
read_lock(&cell->vl_servers_lock);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 12:32:38 +0100