diff options
Diffstat (limited to 'fs/afs/callback.c')
| -rw-r--r-- | fs/afs/callback.c | 509 |
1 files changed, 407 insertions, 102 deletions
diff --git a/fs/afs/callback.c b/fs/afs/callback.c index 9cb206e9d4b..639399f0ab6 100644 --- a/fs/afs/callback.c +++ b/fs/afs/callback.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2002 Red Hat, Inc. All rights reserved. + * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved. * * This software may be freely redistributed under the terms of the * GNU General Public License. @@ -16,85 +16,187 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> -#include "server.h" -#include "vnode.h" +#include <linux/circ_buf.h> #include "internal.h" -#include "cmservice.h" -/*****************************************************************************/ +unsigned afs_vnode_update_timeout = 10; + +#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 */ -int SRXAFSCM_InitCallBackState(struct afs_server *server) +void afs_init_callback_state(struct afs_server *server) { - struct list_head callbacks; + struct afs_vnode *vnode; - _enter("%p", server); + _enter("{%p}", server); - INIT_LIST_HEAD(&callbacks); - - /* transfer the callback list from the server to a temp holding area */ spin_lock(&server->cb_lock); - list_add(&callbacks, &server->cb_promises); - list_del_init(&server->cb_promises); + /* 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 vn=%u uq=%u}", + vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique); + rb_erase(&vnode->cb_promise, &server->cb_promises); + vnode->cb_promised = false; + } - /* munch our way through the list, grabbing the inode, dropping all the - * locks and regetting them in the right order - */ - while (!list_empty(&callbacks)) { - struct afs_vnode *vnode; - struct inode *inode; + spin_unlock(&server->cb_lock); + _leave(""); +} - vnode = list_entry(callbacks.next, struct afs_vnode, cb_link); - list_del_init(&vnode->cb_link); +/* + * handle the data invalidation side of a callback being broken + */ +void afs_broken_callback_work(struct work_struct *work) +{ + struct afs_vnode *vnode = + container_of(work, struct afs_vnode, cb_broken_work); - /* try and grab the inode - may fail */ - inode = igrab(AFS_VNODE_TO_I(vnode)); - if (inode) { - int release = 0; + _enter(""); - spin_unlock(&server->cb_lock); - spin_lock(&vnode->lock); + if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) + return; - if (vnode->cb_server == server) { - vnode->cb_server = NULL; - afs_kafstimod_del_timer(&vnode->cb_timeout); - spin_lock(&afs_cb_hash_lock); - list_del_init(&vnode->cb_hash_link); - spin_unlock(&afs_cb_hash_lock); - release = 1; - } + /* 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 */ - spin_unlock(&vnode->lock); + if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) { + if (S_ISDIR(vnode->vfs_inode.i_mode)) + afs_clear_permits(vnode); - iput(inode); - afs_put_server(server); + if (afs_vnode_fetch_status(vnode, NULL, NULL) < 0) + goto out; - spin_lock(&server->cb_lock); + 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)) { + _debug("zap data {%x:%u}", + vnode->fid.vid, vnode->fid.vnode); + invalidate_remote_inode(&vnode->vfs_inode); } } - spin_unlock(&server->cb_lock); +out: + mutex_unlock(&vnode->validate_lock); - _leave(" = 0"); - return 0; -} /* end SRXAFSCM_InitCallBackState() */ + /* 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); + } + _leave(""); +} + +/* + * actually break a callback + */ +static void afs_break_callback(struct afs_server *server, + struct afs_vnode *vnode) +{ + _enter(""); + + set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); + + 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); + spin_unlock(&vnode->lock); + } +} + +/* + * 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_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; + +found: + _debug("found"); + ASSERTCMP(server, ==, vnode->server); + + if (!igrab(AFS_VNODE_TO_I(vnode))) + goto not_available; + spin_unlock(&server->fs_lock); + + afs_break_callback(server, vnode); + iput(&vnode->vfs_inode); + _leave(""); +} -/*****************************************************************************/ /* * allow the fileserver to break callback promises */ -int SRXAFSCM_CallBack(struct afs_server *server, size_t count, - struct afs_callback callbacks[]) +void afs_break_callbacks(struct afs_server *server, size_t count, + struct afs_callback callbacks[]) { - _enter("%p,%u,", server, count); + _enter("%p,%zu,", server, count); - for (; count > 0; callbacks++, count--) { - struct afs_vnode *vnode = NULL; - struct inode *inode = NULL; - int valid = 0; + ASSERT(server != NULL); + ASSERTCMP(count, <=, AFSCBMAX); + for (; count > 0; callbacks++, count--) { _debug("- Fid { vl=%08x n=%u u=%u } CB { v=%u x=%u t=%u }", callbacks->fid.vid, callbacks->fid.vnode, @@ -103,67 +205,270 @@ int SRXAFSCM_CallBack(struct afs_server *server, size_t count, callbacks->expiry, callbacks->type ); + afs_break_one_callback(server, &callbacks->fid); + } - /* find the inode for this fid */ - spin_lock(&afs_cb_hash_lock); + _leave(""); + return; +} - list_for_each_entry(vnode, - &afs_cb_hash(server, &callbacks->fid), - cb_hash_link) { - if (memcmp(&vnode->fid, &callbacks->fid, - sizeof(struct afs_fid)) != 0) - continue; +/* + * record the callback for breaking + * - the caller must hold server->cb_lock + */ +static void afs_do_give_up_callback(struct afs_server *server, + struct afs_vnode *vnode) +{ + struct afs_callback *cb; - /* right vnode, but is it same server? */ - if (vnode->cb_server != server) - break; /* no */ + _enter("%p,%p", server, vnode); - /* try and nail the inode down */ - inode = igrab(AFS_VNODE_TO_I(vnode)); - break; + 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; + + _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; + } + 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, &afs_async_call); +} + +/* + * flush the outstanding callback breaks on a server + */ +void afs_flush_callback_breaks(struct afs_server *server) +{ + cancel_delayed_work(&server->cb_break_work); + queue_delayed_work(afs_callback_update_worker, + &server->cb_break_work, 0); +} - spin_unlock(&afs_cb_hash_lock); - - if (inode) { - /* we've found the record for this vnode */ - spin_lock(&vnode->lock); - if (vnode->cb_server == server) { - /* the callback _is_ on the calling server */ - vnode->cb_server = NULL; - valid = 1; - - afs_kafstimod_del_timer(&vnode->cb_timeout); - vnode->flags |= AFS_VNODE_CHANGED; - - spin_lock(&server->cb_lock); - list_del_init(&vnode->cb_link); - spin_unlock(&server->cb_lock); - - spin_lock(&afs_cb_hash_lock); - list_del_init(&vnode->cb_hash_link); - spin_unlock(&afs_cb_hash_lock); - } - spin_unlock(&vnode->lock); - - if (valid) { - invalidate_remote_inode(inode); - afs_put_server(server); - } - iput(inode); +#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; + time_t now; + long timeout; + int ret; + + server = container_of(work, struct afs_server, updater); + + _enter(""); + + now = get_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; } - _leave(" = 0"); - return 0; -} /* end SRXAFSCM_CallBack() */ + 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 = get_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 = + create_singlethread_workqueue("kafs_callbackd"); + return afs_callback_update_worker ? 0 : -ENOMEM; +} -/*****************************************************************************/ /* - * allow the fileserver to see if the cache manager is still alive + * shut down the callback update process */ -int SRXAFSCM_Probe(struct afs_server *server) +void __exit afs_callback_update_kill(void) { - _debug("SRXAFSCM_Probe(%p)\n", server); - return 0; -} /* end SRXAFSCM_Probe() */ + destroy_workqueue(afs_callback_update_worker); +} |