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-rw-r--r--fs/afs/callback.c504
1 files changed, 136 insertions, 368 deletions
diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index 25d404d22cae..f4291b576054 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -20,118 +20,151 @@
#include <linux/sched.h>
#include "internal.h"
-#if 0
-unsigned afs_vnode_update_timeout = 10;
-#endif /* 0 */
-
-#define afs_breakring_space(server) \
- CIRC_SPACE((server)->cb_break_head, (server)->cb_break_tail, \
- ARRAY_SIZE((server)->cb_break))
-
-//static void afs_callback_updater(struct work_struct *);
-
-static struct workqueue_struct *afs_callback_update_worker;
-
/*
- * allow the fileserver to request callback state (re-)initialisation
+ * Set up an interest-in-callbacks record for a volume on a server and
+ * register it with the server.
+ * - Called with volume->server_sem held.
*/
-void afs_init_callback_state(struct afs_server *server)
+int afs_register_server_cb_interest(struct afs_vnode *vnode,
+ struct afs_server_entry *entry)
{
- struct afs_vnode *vnode;
-
- _enter("{%p}", server);
+ struct afs_cb_interest *cbi = entry->cb_interest, *vcbi, *new, *x;
+ struct afs_server *server = entry->server;
+
+again:
+ vcbi = vnode->cb_interest;
+ if (vcbi) {
+ if (vcbi == cbi)
+ return 0;
+
+ if (cbi && vcbi->server == cbi->server) {
+ write_seqlock(&vnode->cb_lock);
+ vnode->cb_interest = afs_get_cb_interest(cbi);
+ write_sequnlock(&vnode->cb_lock);
+ afs_put_cb_interest(afs_v2net(vnode), cbi);
+ return 0;
+ }
- spin_lock(&server->cb_lock);
+ if (!cbi && vcbi->server == server) {
+ afs_get_cb_interest(vcbi);
+ x = cmpxchg(&entry->cb_interest, cbi, vcbi);
+ if (x != cbi) {
+ cbi = x;
+ afs_put_cb_interest(afs_v2net(vnode), vcbi);
+ goto again;
+ }
+ return 0;
+ }
+ }
- /* kill all the promises on record from this server */
- while (!RB_EMPTY_ROOT(&server->cb_promises)) {
- vnode = rb_entry(server->cb_promises.rb_node,
- struct afs_vnode, cb_promise);
- _debug("UNPROMISE { vid=%x:%u uq=%u}",
- vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
- rb_erase(&vnode->cb_promise, &server->cb_promises);
- vnode->cb_promised = false;
+ if (!cbi) {
+ new = kzalloc(sizeof(struct afs_cb_interest), GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+
+ refcount_set(&new->usage, 1);
+ new->sb = vnode->vfs_inode.i_sb;
+ new->vid = vnode->volume->vid;
+ new->server = afs_get_server(server);
+ INIT_LIST_HEAD(&new->cb_link);
+
+ write_lock(&server->cb_break_lock);
+ list_add_tail(&new->cb_link, &server->cb_interests);
+ write_unlock(&server->cb_break_lock);
+
+ x = cmpxchg(&entry->cb_interest, cbi, new);
+ if (x == cbi) {
+ cbi = new;
+ } else {
+ cbi = x;
+ afs_put_cb_interest(afs_v2net(vnode), new);
+ }
}
- spin_unlock(&server->cb_lock);
- _leave("");
+ ASSERT(cbi);
+
+ /* Change the server the vnode is using. This entails scrubbing any
+ * interest the vnode had in the previous server it was using.
+ */
+ write_seqlock(&vnode->cb_lock);
+
+ vnode->cb_interest = afs_get_cb_interest(cbi);
+ vnode->cb_s_break = cbi->server->cb_s_break;
+ clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
+
+ write_sequnlock(&vnode->cb_lock);
+ return 0;
}
/*
- * handle the data invalidation side of a callback being broken
+ * Set a vnode's interest on a server.
*/
-void afs_broken_callback_work(struct work_struct *work)
+void afs_set_cb_interest(struct afs_vnode *vnode, struct afs_cb_interest *cbi)
{
- struct afs_vnode *vnode =
- container_of(work, struct afs_vnode, cb_broken_work);
+ struct afs_cb_interest *old_cbi = NULL;
- _enter("");
-
- if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
+ if (vnode->cb_interest == cbi)
return;
- /* we're only interested in dealing with a broken callback on *this*
- * vnode and only if no-one else has dealt with it yet */
- if (!mutex_trylock(&vnode->validate_lock))
- return; /* someone else is dealing with it */
-
- if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
- if (S_ISDIR(vnode->vfs_inode.i_mode))
- afs_clear_permits(vnode);
-
- if (afs_vnode_fetch_status(vnode, NULL, NULL) < 0)
- goto out;
-
- if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
- goto out;
-
- /* if the vnode's data version number changed then its contents
- * are different */
- if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
- afs_zap_data(vnode);
+ write_seqlock(&vnode->cb_lock);
+ if (vnode->cb_interest != cbi) {
+ afs_get_cb_interest(cbi);
+ old_cbi = vnode->cb_interest;
+ vnode->cb_interest = cbi;
}
+ write_sequnlock(&vnode->cb_lock);
+ afs_put_cb_interest(afs_v2net(vnode), cbi);
+}
-out:
- mutex_unlock(&vnode->validate_lock);
-
- /* avoid the potential race whereby the mutex_trylock() in this
- * function happens again between the clear_bit() and the
- * mutex_unlock() */
- if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
- _debug("requeue");
- queue_work(afs_callback_update_worker, &vnode->cb_broken_work);
+/*
+ * Remove an interest on a server.
+ */
+void afs_put_cb_interest(struct afs_net *net, struct afs_cb_interest *cbi)
+{
+ if (cbi && refcount_dec_and_test(&cbi->usage)) {
+ if (!list_empty(&cbi->cb_link)) {
+ write_lock(&cbi->server->cb_break_lock);
+ list_del_init(&cbi->cb_link);
+ write_unlock(&cbi->server->cb_break_lock);
+ afs_put_server(net, cbi->server);
+ }
+ kfree(cbi);
}
- _leave("");
+}
+
+/*
+ * allow the fileserver to request callback state (re-)initialisation
+ */
+void afs_init_callback_state(struct afs_server *server)
+{
+ if (!test_and_clear_bit(AFS_SERVER_FL_NEW, &server->flags))
+ server->cb_s_break++;
}
/*
* actually break a callback
*/
-static void afs_break_callback(struct afs_server *server,
- struct afs_vnode *vnode)
+void afs_break_callback(struct afs_vnode *vnode)
{
_enter("");
- set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
+ write_seqlock(&vnode->cb_lock);
+
+ if (test_and_clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
+ vnode->cb_break++;
+ afs_clear_permits(vnode);
- if (vnode->cb_promised) {
spin_lock(&vnode->lock);
_debug("break callback");
- spin_lock(&server->cb_lock);
- if (vnode->cb_promised) {
- rb_erase(&vnode->cb_promise, &server->cb_promises);
- vnode->cb_promised = false;
- }
- spin_unlock(&server->cb_lock);
-
- queue_work(afs_callback_update_worker, &vnode->cb_broken_work);
if (list_empty(&vnode->granted_locks) &&
!list_empty(&vnode->pending_locks))
afs_lock_may_be_available(vnode);
spin_unlock(&vnode->lock);
}
+
+ write_sequnlock(&vnode->cb_lock);
}
/*
@@ -143,49 +176,31 @@ static void afs_break_callback(struct afs_server *server,
static void afs_break_one_callback(struct afs_server *server,
struct afs_fid *fid)
{
+ struct afs_cb_interest *cbi;
+ struct afs_iget_data data;
struct afs_vnode *vnode;
- struct rb_node *p;
-
- _debug("find");
- spin_lock(&server->fs_lock);
- p = server->fs_vnodes.rb_node;
- while (p) {
- vnode = rb_entry(p, struct afs_vnode, server_rb);
- if (fid->vid < vnode->fid.vid)
- p = p->rb_left;
- else if (fid->vid > vnode->fid.vid)
- p = p->rb_right;
- else if (fid->vnode < vnode->fid.vnode)
- p = p->rb_left;
- else if (fid->vnode > vnode->fid.vnode)
- p = p->rb_right;
- else if (fid->unique < vnode->fid.unique)
- p = p->rb_left;
- else if (fid->unique > vnode->fid.unique)
- p = p->rb_right;
- else
- goto found;
- }
-
- /* not found so we just ignore it (it may have moved to another
- * server) */
-not_available:
- _debug("not avail");
- spin_unlock(&server->fs_lock);
- _leave("");
- return;
+ struct inode *inode;
-found:
- _debug("found");
- ASSERTCMP(server, ==, vnode->server);
+ read_lock(&server->cb_break_lock);
- if (!igrab(AFS_VNODE_TO_I(vnode)))
- goto not_available;
- spin_unlock(&server->fs_lock);
+ /* Step through all interested superblocks. There may be more than one
+ * because of cell aliasing.
+ */
+ list_for_each_entry(cbi, &server->cb_interests, cb_link) {
+ if (cbi->vid != fid->vid)
+ continue;
+
+ data.volume = NULL;
+ data.fid = *fid;
+ inode = ilookup5_nowait(cbi->sb, fid->vnode, afs_iget5_test, &data);
+ if (inode) {
+ vnode = AFS_FS_I(inode);
+ afs_break_callback(vnode);
+ iput(inode);
+ }
+ }
- afs_break_callback(server, vnode);
- iput(&vnode->vfs_inode);
- _leave("");
+ read_unlock(&server->cb_break_lock);
}
/*
@@ -216,261 +231,14 @@ void afs_break_callbacks(struct afs_server *server, size_t count,
}
/*
- * record the callback for breaking
- * - the caller must hold server->cb_lock
+ * Clear the callback interests in a server list.
*/
-static void afs_do_give_up_callback(struct afs_server *server,
- struct afs_vnode *vnode)
+void afs_clear_callback_interests(struct afs_net *net, struct afs_server_list *slist)
{
- struct afs_callback *cb;
-
- _enter("%p,%p", server, vnode);
-
- cb = &server->cb_break[server->cb_break_head];
- cb->fid = vnode->fid;
- cb->version = vnode->cb_version;
- cb->expiry = vnode->cb_expiry;
- cb->type = vnode->cb_type;
- smp_wmb();
- server->cb_break_head =
- (server->cb_break_head + 1) &
- (ARRAY_SIZE(server->cb_break) - 1);
-
- /* defer the breaking of callbacks to try and collect as many as
- * possible to ship in one operation */
- switch (atomic_inc_return(&server->cb_break_n)) {
- case 1 ... AFSCBMAX - 1:
- queue_delayed_work(afs_callback_update_worker,
- &server->cb_break_work, HZ * 2);
- break;
- case AFSCBMAX:
- afs_flush_callback_breaks(server);
- break;
- default:
- break;
- }
-
- ASSERT(server->cb_promises.rb_node != NULL);
- rb_erase(&vnode->cb_promise, &server->cb_promises);
- vnode->cb_promised = false;
- _leave("");
-}
-
-/*
- * discard the callback on a deleted item
- */
-void afs_discard_callback_on_delete(struct afs_vnode *vnode)
-{
- struct afs_server *server = vnode->server;
+ int i;
- _enter("%d", vnode->cb_promised);
-
- if (!vnode->cb_promised) {
- _leave(" [not promised]");
- return;
- }
-
- ASSERT(server != NULL);
-
- spin_lock(&server->cb_lock);
- if (vnode->cb_promised) {
- ASSERT(server->cb_promises.rb_node != NULL);
- rb_erase(&vnode->cb_promise, &server->cb_promises);
- vnode->cb_promised = false;
+ for (i = 0; i < slist->nr_servers; i++) {
+ afs_put_cb_interest(net, slist->servers[i].cb_interest);
+ slist->servers[i].cb_interest = NULL;
}
- spin_unlock(&server->cb_lock);
- _leave("");
-}
-
-/*
- * give up the callback registered for a vnode on the file server when the
- * inode is being cleared
- */
-void afs_give_up_callback(struct afs_vnode *vnode)
-{
- struct afs_server *server = vnode->server;
-
- DECLARE_WAITQUEUE(myself, current);
-
- _enter("%d", vnode->cb_promised);
-
- _debug("GIVE UP INODE %p", &vnode->vfs_inode);
-
- if (!vnode->cb_promised) {
- _leave(" [not promised]");
- return;
- }
-
- ASSERT(server != NULL);
-
- spin_lock(&server->cb_lock);
- if (vnode->cb_promised && afs_breakring_space(server) == 0) {
- add_wait_queue(&server->cb_break_waitq, &myself);
- for (;;) {
- set_current_state(TASK_UNINTERRUPTIBLE);
- if (!vnode->cb_promised ||
- afs_breakring_space(server) != 0)
- break;
- spin_unlock(&server->cb_lock);
- schedule();
- spin_lock(&server->cb_lock);
- }
- remove_wait_queue(&server->cb_break_waitq, &myself);
- __set_current_state(TASK_RUNNING);
- }
-
- /* of course, it's always possible for the server to break this vnode's
- * callback first... */
- if (vnode->cb_promised)
- afs_do_give_up_callback(server, vnode);
-
- spin_unlock(&server->cb_lock);
- _leave("");
-}
-
-/*
- * dispatch a deferred give up callbacks operation
- */
-void afs_dispatch_give_up_callbacks(struct work_struct *work)
-{
- struct afs_server *server =
- container_of(work, struct afs_server, cb_break_work.work);
-
- _enter("");
-
- /* tell the fileserver to discard the callback promises it has
- * - in the event of ENOMEM or some other error, we just forget that we
- * had callbacks entirely, and the server will call us later to break
- * them
- */
- afs_fs_give_up_callbacks(server, true);
-}
-
-/*
- * flush the outstanding callback breaks on a server
- */
-void afs_flush_callback_breaks(struct afs_server *server)
-{
- mod_delayed_work(afs_callback_update_worker, &server->cb_break_work, 0);
-}
-
-#if 0
-/*
- * update a bunch of callbacks
- */
-static void afs_callback_updater(struct work_struct *work)
-{
- struct afs_server *server;
- struct afs_vnode *vnode, *xvnode;
- time64_t now;
- long timeout;
- int ret;
-
- server = container_of(work, struct afs_server, updater);
-
- _enter("");
-
- now = ktime_get_real_seconds();
-
- /* find the first vnode to update */
- spin_lock(&server->cb_lock);
- for (;;) {
- if (RB_EMPTY_ROOT(&server->cb_promises)) {
- spin_unlock(&server->cb_lock);
- _leave(" [nothing]");
- return;
- }
-
- vnode = rb_entry(rb_first(&server->cb_promises),
- struct afs_vnode, cb_promise);
- if (atomic_read(&vnode->usage) > 0)
- break;
- rb_erase(&vnode->cb_promise, &server->cb_promises);
- vnode->cb_promised = false;
- }
-
- timeout = vnode->update_at - now;
- if (timeout > 0) {
- queue_delayed_work(afs_vnode_update_worker,
- &afs_vnode_update, timeout * HZ);
- spin_unlock(&server->cb_lock);
- _leave(" [nothing]");
- return;
- }
-
- list_del_init(&vnode->update);
- atomic_inc(&vnode->usage);
- spin_unlock(&server->cb_lock);
-
- /* we can now perform the update */
- _debug("update %s", vnode->vldb.name);
- vnode->state = AFS_VL_UPDATING;
- vnode->upd_rej_cnt = 0;
- vnode->upd_busy_cnt = 0;
-
- ret = afs_vnode_update_record(vl, &vldb);
- switch (ret) {
- case 0:
- afs_vnode_apply_update(vl, &vldb);
- vnode->state = AFS_VL_UPDATING;
- break;
- case -ENOMEDIUM:
- vnode->state = AFS_VL_VOLUME_DELETED;
- break;
- default:
- vnode->state = AFS_VL_UNCERTAIN;
- break;
- }
-
- /* and then reschedule */
- _debug("reschedule");
- vnode->update_at = ktime_get_real_seconds() +
- afs_vnode_update_timeout;
-
- spin_lock(&server->cb_lock);
-
- if (!list_empty(&server->cb_promises)) {
- /* next update in 10 minutes, but wait at least 1 second more
- * than the newest record already queued so that we don't spam
- * the VL server suddenly with lots of requests
- */
- xvnode = list_entry(server->cb_promises.prev,
- struct afs_vnode, update);
- if (vnode->update_at <= xvnode->update_at)
- vnode->update_at = xvnode->update_at + 1;
- xvnode = list_entry(server->cb_promises.next,
- struct afs_vnode, update);
- timeout = xvnode->update_at - now;
- if (timeout < 0)
- timeout = 0;
- } else {
- timeout = afs_vnode_update_timeout;
- }
-
- list_add_tail(&vnode->update, &server->cb_promises);
-
- _debug("timeout %ld", timeout);
- queue_delayed_work(afs_vnode_update_worker,
- &afs_vnode_update, timeout * HZ);
- spin_unlock(&server->cb_lock);
- afs_put_vnode(vl);
-}
-#endif
-
-/*
- * initialise the callback update process
- */
-int __init afs_callback_update_init(void)
-{
- afs_callback_update_worker = alloc_ordered_workqueue("kafs_callbackd",
- WQ_MEM_RECLAIM);
- return afs_callback_update_worker ? 0 : -ENOMEM;
-}
-
-/*
- * shut down the callback update process
- */
-void afs_callback_update_kill(void)
-{
- destroy_workqueue(afs_callback_update_worker);
}