afs: Defer volume record destruction to a workqueue

Defer volume record destruction to a workqueue so that afs_put_volume()
isn't going to run the destruction process in the callback workqueue whilst
the server is holding up other clients whilst waiting for us to reply to a
CB.CallBack notification RPC.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
This commit is contained in:
David Howells 2023-11-08 13:01:11 +00:00
parent ca0e79a460
commit 445f9b6952
6 changed files with 19 additions and 16 deletions

View File

@ -818,7 +818,7 @@ done:
final_destruction:
/* The root volume is pinning the cell */
afs_put_volume(cell->net, cell->root_volume, afs_volume_trace_put_cell_root);
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);
}

View File

@ -265,7 +265,7 @@ int afs_put_operation(struct afs_operation *op)
}
afs_put_serverlist(op->net, op->server_list);
afs_put_volume(op->net, op->volume, afs_volume_trace_put_put_op);
afs_put_volume(op->volume, afs_volume_trace_put_put_op);
key_put(op->key);
kfree(op);
return ret;

View File

@ -636,6 +636,7 @@ struct afs_volume {
struct rb_node cell_node; /* Link in cell->volumes */
struct hlist_node proc_link; /* Link in cell->proc_volumes */
struct super_block __rcu *sb; /* Superblock on which inodes reside */
struct work_struct destructor; /* Deferred destructor */
unsigned long flags;
#define AFS_VOLUME_NEEDS_UPDATE 0 /* - T if an update needs performing */
#define AFS_VOLUME_UPDATING 1 /* - T if an update is in progress */
@ -1613,7 +1614,7 @@ extern int afs_activate_volume(struct afs_volume *);
extern void afs_deactivate_volume(struct afs_volume *);
bool afs_try_get_volume(struct afs_volume *volume, enum afs_volume_trace reason);
extern struct afs_volume *afs_get_volume(struct afs_volume *, enum afs_volume_trace);
extern void afs_put_volume(struct afs_net *, struct afs_volume *, enum afs_volume_trace);
void afs_put_volume(struct afs_volume *volume, enum afs_volume_trace reason);
extern int afs_check_volume_status(struct afs_volume *, struct afs_operation *);
/*

View File

@ -381,8 +381,7 @@ static int afs_validate_fc(struct fs_context *fc)
ctx->key = key;
if (ctx->volume) {
afs_put_volume(ctx->net, ctx->volume,
afs_volume_trace_put_validate_fc);
afs_put_volume(ctx->volume, afs_volume_trace_put_validate_fc);
ctx->volume = NULL;
}
@ -529,7 +528,7 @@ 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_volume(as->volume, afs_volume_trace_put_destroy_sbi);
afs_unuse_cell(net, as->cell, afs_cell_trace_unuse_sbi);
put_net(as->net_ns);
kfree(as);
@ -615,7 +614,7 @@ static void afs_free_fc(struct fs_context *fc)
struct afs_fs_context *ctx = fc->fs_private;
afs_destroy_sbi(fc->s_fs_info);
afs_put_volume(ctx->net, ctx->volume, afs_volume_trace_put_free_fc);
afs_put_volume(ctx->volume, afs_volume_trace_put_free_fc);
afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc);
key_put(ctx->key);
kfree(ctx);

View File

@ -156,7 +156,7 @@ static int afs_query_for_alias_one(struct afs_cell *cell, struct key *key,
/* And see if it's in the new cell. */
volume = afs_sample_volume(cell, key, pvol->name, pvol->name_len);
if (IS_ERR(volume)) {
afs_put_volume(cell->net, pvol, afs_volume_trace_put_query_alias);
afs_put_volume(pvol, afs_volume_trace_put_query_alias);
if (PTR_ERR(volume) != -ENOMEDIUM)
return PTR_ERR(volume);
/* That volume is not in the new cell, so not an alias */
@ -174,8 +174,8 @@ static int afs_query_for_alias_one(struct afs_cell *cell, struct key *key,
rcu_read_unlock();
}
afs_put_volume(cell->net, volume, afs_volume_trace_put_query_alias);
afs_put_volume(cell->net, pvol, afs_volume_trace_put_query_alias);
afs_put_volume(volume, afs_volume_trace_put_query_alias);
afs_put_volume(pvol, afs_volume_trace_put_query_alias);
return ret;
}

View File

@ -11,6 +11,8 @@
static unsigned __read_mostly afs_volume_record_life = 60 * 60;
static void afs_destroy_volume(struct work_struct *work);
/*
* Insert a volume into a cell. If there's an existing volume record, that is
* returned instead with a ref held.
@ -91,6 +93,7 @@ static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
refcount_set(&volume->ref, 1);
INIT_HLIST_NODE(&volume->proc_link);
INIT_WORK(&volume->destructor, afs_destroy_volume);
rwlock_init(&volume->servers_lock);
rwlock_init(&volume->cb_v_break_lock);
memcpy(volume->name, vldb->name, vldb->name_len + 1);
@ -133,7 +136,7 @@ static struct afs_volume *afs_lookup_volume(struct afs_fs_context *params,
if (volume == candidate)
afs_attach_volume_to_servers(volume, slist);
else
afs_put_volume(params->net, candidate, afs_volume_trace_put_cell_dup);
afs_put_volume(candidate, afs_volume_trace_put_cell_dup);
return volume;
}
@ -223,8 +226,9 @@ error:
/*
* Destroy a volume record
*/
static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume)
static void afs_destroy_volume(struct work_struct *work)
{
struct afs_volume *volume = container_of(work, struct afs_volume, destructor);
struct afs_server_list *slist = rcu_access_pointer(volume->servers);
_enter("%p", volume);
@ -235,7 +239,7 @@ static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume)
afs_detach_volume_from_servers(volume, slist);
afs_remove_volume_from_cell(volume);
afs_put_serverlist(net, slist);
afs_put_serverlist(volume->cell->net, slist);
afs_put_cell(volume->cell, afs_cell_trace_put_vol);
trace_afs_volume(volume->vid, refcount_read(&volume->ref),
afs_volume_trace_free);
@ -277,8 +281,7 @@ struct afs_volume *afs_get_volume(struct afs_volume *volume,
/*
* Drop a reference on a volume record.
*/
void afs_put_volume(struct afs_net *net, struct afs_volume *volume,
enum afs_volume_trace reason)
void afs_put_volume(struct afs_volume *volume, enum afs_volume_trace reason)
{
if (volume) {
afs_volid_t vid = volume->vid;
@ -288,7 +291,7 @@ void afs_put_volume(struct afs_net *net, struct afs_volume *volume,
zero = __refcount_dec_and_test(&volume->ref, &r);
trace_afs_volume(vid, r - 1, reason);
if (zero)
afs_destroy_volume(net, volume);
schedule_work(&volume->destructor);
}
}