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-rw-r--r--fs/afs/callback.c150
-rw-r--r--fs/afs/internal.h6
-rw-r--r--fs/afs/server.c4
3 files changed, 100 insertions, 60 deletions
diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index 0dcbd40732d1..b16781e1683e 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -28,7 +28,7 @@ static struct afs_cb_interest *afs_create_interest(struct afs_server *server,
{
struct afs_vol_interest *new_vi, *vi;
struct afs_cb_interest *new;
- struct hlist_node **pp;
+ struct rb_node *parent, **pp;
new_vi = kzalloc(sizeof(struct afs_vol_interest), GFP_KERNEL);
if (!new_vi)
@@ -42,7 +42,6 @@ static struct afs_cb_interest *afs_create_interest(struct afs_server *server,
new_vi->usage = 1;
new_vi->vid = vnode->volume->vid;
- INIT_HLIST_NODE(&new_vi->srv_link);
INIT_HLIST_HEAD(&new_vi->cb_interests);
refcount_set(&new->usage, 1);
@@ -51,31 +50,31 @@ static struct afs_cb_interest *afs_create_interest(struct afs_server *server,
new->server = afs_get_server(server, afs_server_trace_get_new_cbi);
INIT_HLIST_NODE(&new->cb_vlink);
- write_lock(&server->cb_break_lock);
+ write_seqlock(&server->cb_break_lock);
- for (pp = &server->cb_volumes.first; *pp; pp = &(*pp)->next) {
- vi = hlist_entry(*pp, struct afs_vol_interest, srv_link);
- if (vi->vid < new_vi->vid)
- continue;
- if (vi->vid > new_vi->vid)
- break;
- vi->usage++;
- goto found_vi;
+ pp = &server->cb_volumes.rb_node;
+ while ((parent = *pp)) {
+ vi = rb_entry(parent, struct afs_vol_interest, srv_node);
+ if (vi->vid < new_vi->vid) {
+ pp = &(*pp)->rb_left;
+ } else if (vi->vid > new_vi->vid) {
+ pp = &(*pp)->rb_right;
+ } else {
+ vi->usage++;
+ goto found_vi;
+ }
}
- new_vi->srv_link.pprev = pp;
- new_vi->srv_link.next = *pp;
- if (*pp)
- (*pp)->pprev = &new_vi->srv_link.next;
- *pp = &new_vi->srv_link;
vi = new_vi;
new_vi = NULL;
-found_vi:
+ rb_link_node_rcu(&vi->srv_node, parent, pp);
+ rb_insert_color(&vi->srv_node, &server->cb_volumes);
+found_vi:
new->vol_interest = vi;
hlist_add_head(&new->cb_vlink, &vi->cb_interests);
- write_unlock(&server->cb_break_lock);
+ write_sequnlock(&server->cb_break_lock);
kfree(new_vi);
return new;
}
@@ -182,17 +181,17 @@ void afs_put_cb_interest(struct afs_net *net, struct afs_cb_interest *cbi)
if (cbi && refcount_dec_and_test(&cbi->usage)) {
if (!hlist_unhashed(&cbi->cb_vlink)) {
- write_lock(&cbi->server->cb_break_lock);
+ write_seqlock(&cbi->server->cb_break_lock);
hlist_del_init(&cbi->cb_vlink);
vi = cbi->vol_interest;
cbi->vol_interest = NULL;
if (--vi->usage == 0)
- hlist_del(&vi->srv_link);
+ rb_erase(&vi->srv_node, &cbi->server->cb_volumes);
else
vi = NULL;
- write_unlock(&cbi->server->cb_break_lock);
+ write_sequnlock(&cbi->server->cb_break_lock);
if (vi)
kfree_rcu(vi, rcu);
afs_put_server(net, cbi->server, afs_server_trace_put_cbi);
@@ -238,43 +237,63 @@ void afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason
}
/*
+ * Look up a volume interest by volume ID under RCU conditions.
+ */
+static struct afs_vol_interest *afs_lookup_vol_interest_rcu(struct afs_server *server,
+ afs_volid_t vid)
+{
+ struct afs_vol_interest *vi = NULL;
+ struct rb_node *p;
+ int seq = 0;
+
+ do {
+ /* Unfortunately, rbtree walking doesn't give reliable results
+ * under just the RCU read lock, so we have to check for
+ * changes.
+ */
+ read_seqbegin_or_lock(&server->cb_break_lock, &seq);
+
+ p = rcu_dereference_raw(server->cb_volumes.rb_node);
+ while (p) {
+ vi = rb_entry(p, struct afs_vol_interest, srv_node);
+
+ if (vi->vid < vid)
+ p = rcu_dereference_raw(p->rb_left);
+ else if (vi->vid > vid)
+ p = rcu_dereference_raw(p->rb_right);
+ else
+ break;
+ /* We want to repeat the search, this time with the
+ * lock properly locked.
+ */
+ vi = NULL;
+ }
+
+ } while (need_seqretry(&server->cb_break_lock, seq));
+
+ done_seqretry(&server->cb_break_lock, seq);
+ return vi;
+}
+
+/*
* allow the fileserver to explicitly break one callback
* - happens when
* - the backing file is changed
* - a lock is released
*/
static void afs_break_one_callback(struct afs_server *server,
- struct afs_fid *fid)
+ struct afs_fid *fid,
+ struct afs_vol_interest *vi)
{
- struct afs_vol_interest *vi;
struct afs_cb_interest *cbi;
struct afs_iget_data data;
struct afs_vnode *vnode;
struct inode *inode;
- rcu_read_lock();
- read_lock(&server->cb_break_lock);
- hlist_for_each_entry(vi, &server->cb_volumes, srv_link) {
- if (vi->vid < fid->vid)
- continue;
- if (vi->vid > fid->vid) {
- vi = NULL;
- break;
- }
- //atomic_inc(&vi->usage);
- break;
- }
-
- /* TODO: Find all matching volumes if we couldn't match the server and
- * break them anyway.
- */
- if (!vi)
- goto out;
-
/* Step through all interested superblocks. There may be more than one
* because of cell aliasing.
*/
- hlist_for_each_entry(cbi, &vi->cb_interests, cb_vlink) {
+ hlist_for_each_entry_rcu(cbi, &vi->cb_interests, cb_vlink) {
if (fid->vnode == 0 && fid->unique == 0) {
/* The callback break applies to an entire volume. */
struct afs_super_info *as = AFS_FS_S(cbi->sb);
@@ -303,10 +322,36 @@ static void afs_break_one_callback(struct afs_server *server,
}
}
}
+}
-out:
- read_unlock(&server->cb_break_lock);
- rcu_read_unlock();
+static void afs_break_some_callbacks(struct afs_server *server,
+ struct afs_callback_break *cbb,
+ size_t *_count)
+{
+ struct afs_callback_break *residue = cbb;
+ struct afs_vol_interest *vi;
+ afs_volid_t vid = cbb->fid.vid;
+ size_t i;
+
+ vi = afs_lookup_vol_interest_rcu(server, vid);
+
+ /* TODO: Find all matching volumes if we couldn't match the server and
+ * break them anyway.
+ */
+
+ for (i = *_count; i > 0; cbb++, i--) {
+ if (cbb->fid.vid == vid) {
+ _debug("- Fid { vl=%08llx n=%llu u=%u }",
+ cbb->fid.vid,
+ cbb->fid.vnode,
+ cbb->fid.unique);
+ --*_count;
+ if (vi)
+ afs_break_one_callback(server, &cbb->fid, vi);
+ } else {
+ *residue++ = *cbb;
+ }
+ }
}
/*
@@ -319,17 +364,12 @@ void afs_break_callbacks(struct afs_server *server, size_t count,
ASSERT(server != NULL);
- /* TODO: Sort the callback break list by volume ID */
+ rcu_read_lock();
- for (; count > 0; callbacks++, count--) {
- _debug("- Fid { vl=%08llx n=%llu u=%u }",
- callbacks->fid.vid,
- callbacks->fid.vnode,
- callbacks->fid.unique);
- afs_break_one_callback(server, &callbacks->fid);
- }
+ while (count > 0)
+ afs_break_some_callbacks(server, callbacks, &count);
- _leave("");
+ rcu_read_unlock();
return;
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 61320a632e15..b6665fc5d355 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -524,9 +524,9 @@ struct afs_server {
rwlock_t fs_lock; /* access lock */
/* callback promise management */
- struct hlist_head cb_volumes; /* List of volume interests on this server */
+ struct rb_root cb_volumes; /* List of volume interests on this server */
unsigned cb_s_break; /* Break-everything counter. */
- rwlock_t cb_break_lock; /* Volume finding lock */
+ seqlock_t cb_break_lock; /* Volume finding lock */
/* Probe state */
unsigned long probed_at; /* Time last probe was dispatched (jiffies) */
@@ -552,7 +552,7 @@ struct afs_server {
* Volume collation in the server's callback interest list.
*/
struct afs_vol_interest {
- struct hlist_node srv_link; /* Link in server->cb_volumes */
+ struct rb_node srv_node; /* Link in server->cb_volumes */
struct hlist_head cb_interests; /* List of callback interests on the server */
union {
struct rcu_head rcu;
diff --git a/fs/afs/server.c b/fs/afs/server.c
index 3f707b5ecb62..5ed90f419c54 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -212,8 +212,8 @@ static struct afs_server *afs_alloc_server(struct afs_net *net,
server->addr_version = alist->version;
server->uuid = *uuid;
rwlock_init(&server->fs_lock);
- INIT_HLIST_HEAD(&server->cb_volumes);
- rwlock_init(&server->cb_break_lock);
+ server->cb_volumes = RB_ROOT;
+ seqlock_init(&server->cb_break_lock);
init_waitqueue_head(&server->probe_wq);
INIT_LIST_HEAD(&server->probe_link);
spin_lock_init(&server->probe_lock);
generated by cgit v1.2.3 (git 2.39.0) at 2024-08-01 11:47:40 +0300