#define AFS_LOCK_GRANTED 0
#define AFS_LOCK_PENDING 1
+#define AFS_LOCK_YOUR_TRY 2
struct workqueue_struct *afs_lock_manager;
+static void afs_next_locker(struct afs_vnode *vnode, int error);
static void afs_fl_copy_lock(struct file_lock *new, struct file_lock *fl);
static void afs_fl_release_private(struct file_lock *fl);
.fl_release_private = afs_fl_release_private,
};
+static inline void afs_set_lock_state(struct afs_vnode *vnode, enum afs_lock_state state)
+{
+ _debug("STATE %u -> %u", vnode->lock_state, state);
+ vnode->lock_state = state;
+}
+
+static atomic_t afs_file_lock_debug_id;
+
/*
* if the callback is broken on this vnode, then the lock may now be available
*/
{
_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
- queue_delayed_work(afs_lock_manager, &vnode->lock_work, 0);
+ spin_lock(&vnode->lock);
+ if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB)
+ afs_next_locker(vnode, 0);
+ trace_afs_flock_ev(vnode, NULL, afs_flock_callback_break, 0);
+ spin_unlock(&vnode->lock);
}
/*
*/
static void afs_schedule_lock_extension(struct afs_vnode *vnode)
{
- queue_delayed_work(afs_lock_manager, &vnode->lock_work,
- AFS_LOCKWAIT * HZ / 2);
+ ktime_t expires_at, now, duration;
+ u64 duration_j;
+
+ expires_at = ktime_add_ms(vnode->locked_at, AFS_LOCKWAIT * 1000 / 2);
+ now = ktime_get_real();
+ duration = ktime_sub(expires_at, now);
+ if (duration <= 0)
+ duration_j = 0;
+ else
+ duration_j = nsecs_to_jiffies(ktime_to_ns(duration));
+
+ queue_delayed_work(afs_lock_manager, &vnode->lock_work, duration_j);
+}
+
+/*
+ * In the case of successful completion of a lock operation, record the time
+ * the reply appeared and start the lock extension timer.
+ */
+void afs_lock_op_done(struct afs_call *call)
+{
+ struct afs_vnode *vnode = call->reply[0];
+
+ if (call->error == 0) {
+ spin_lock(&vnode->lock);
+ trace_afs_flock_ev(vnode, NULL, afs_flock_timestamp, 0);
+ vnode->locked_at = call->reply_time;
+ afs_schedule_lock_extension(vnode);
+ spin_unlock(&vnode->lock);
+ }
}
/*
* first lock in the queue is itself a readlock)
* - the caller must hold the vnode lock
*/
-static void afs_grant_locks(struct afs_vnode *vnode, struct file_lock *fl)
+static void afs_grant_locks(struct afs_vnode *vnode)
{
struct file_lock *p, *_p;
+ bool exclusive = (vnode->lock_type == AFS_LOCK_WRITE);
- list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
- if (fl->fl_type == F_RDLCK) {
- list_for_each_entry_safe(p, _p, &vnode->pending_locks,
- fl_u.afs.link) {
- if (p->fl_type == F_RDLCK) {
- p->fl_u.afs.state = AFS_LOCK_GRANTED;
- list_move_tail(&p->fl_u.afs.link,
- &vnode->granted_locks);
- wake_up(&p->fl_wait);
- }
+ list_for_each_entry_safe(p, _p, &vnode->pending_locks, fl_u.afs.link) {
+ if (!exclusive && p->fl_type == F_WRLCK)
+ continue;
+
+ list_move_tail(&p->fl_u.afs.link, &vnode->granted_locks);
+ p->fl_u.afs.state = AFS_LOCK_GRANTED;
+ trace_afs_flock_op(vnode, p, afs_flock_op_grant);
+ wake_up(&p->fl_wait);
+ }
+}
+
+/*
+ * If an error is specified, reject every pending lock that matches the
+ * authentication and type of the lock we failed to get. If there are any
+ * remaining lockers, try to wake up one of them to have a go.
+ */
+static void afs_next_locker(struct afs_vnode *vnode, int error)
+{
+ struct file_lock *p, *_p, *next = NULL;
+ struct key *key = vnode->lock_key;
+ unsigned int fl_type = F_RDLCK;
+
+ _enter("");
+
+ if (vnode->lock_type == AFS_LOCK_WRITE)
+ fl_type = F_WRLCK;
+
+ list_for_each_entry_safe(p, _p, &vnode->pending_locks, fl_u.afs.link) {
+ if (error &&
+ p->fl_type == fl_type &&
+ afs_file_key(p->fl_file) == key) {
+ list_del_init(&p->fl_u.afs.link);
+ p->fl_u.afs.state = error;
+ wake_up(&p->fl_wait);
}
+
+ /* Select the next locker to hand off to. */
+ if (next &&
+ (next->fl_type == F_WRLCK || p->fl_type == F_RDLCK))
+ continue;
+ next = p;
+ }
+
+ vnode->lock_key = NULL;
+ key_put(key);
+
+ if (next) {
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING);
+ next->fl_u.afs.state = AFS_LOCK_YOUR_TRY;
+ trace_afs_flock_op(vnode, next, afs_flock_op_wake);
+ wake_up(&next->fl_wait);
+ } else {
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_NONE);
+ trace_afs_flock_ev(vnode, NULL, afs_flock_no_lockers, 0);
}
+
+ _leave("");
+}
+
+/*
+ * Kill off all waiters in the the pending lock queue due to the vnode being
+ * deleted.
+ */
+static void afs_kill_lockers_enoent(struct afs_vnode *vnode)
+{
+ struct file_lock *p;
+
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_DELETED);
+
+ while (!list_empty(&vnode->pending_locks)) {
+ p = list_entry(vnode->pending_locks.next,
+ struct file_lock, fl_u.afs.link);
+ list_del_init(&p->fl_u.afs.link);
+ p->fl_u.afs.state = -ENOENT;
+ wake_up(&p->fl_wait);
+ }
+
+ key_put(vnode->lock_key);
+ vnode->lock_key = NULL;
}
/*
key_serial(key), type);
ret = -ERESTARTSYS;
- if (afs_begin_vnode_operation(&fc, vnode, key)) {
+ if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(vnode);
afs_fs_set_lock(&fc, type);
key_serial(key));
ret = -ERESTARTSYS;
- if (afs_begin_vnode_operation(&fc, vnode, key)) {
+ if (afs_begin_vnode_operation(&fc, vnode, key, false)) {
while (afs_select_current_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(vnode);
afs_fs_extend_lock(&fc);
key_serial(key));
ret = -ERESTARTSYS;
- if (afs_begin_vnode_operation(&fc, vnode, key)) {
+ if (afs_begin_vnode_operation(&fc, vnode, key, false)) {
while (afs_select_current_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(vnode);
afs_fs_release_lock(&fc);
{
struct afs_vnode *vnode =
container_of(work, struct afs_vnode, lock_work.work);
- struct file_lock *fl, *next;
- afs_lock_type_t type;
struct key *key;
int ret;
_debug("wstate %u for %p", vnode->lock_state, vnode);
switch (vnode->lock_state) {
case AFS_VNODE_LOCK_NEED_UNLOCK:
- _debug("unlock");
- vnode->lock_state = AFS_VNODE_LOCK_UNLOCKING;
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_UNLOCKING);
+ trace_afs_flock_ev(vnode, NULL, afs_flock_work_unlocking, 0);
spin_unlock(&vnode->lock);
/* attempt to release the server lock; if it fails, we just
* wait 5 minutes and it'll expire anyway */
ret = afs_release_lock(vnode, vnode->lock_key);
- if (ret < 0)
+ if (ret < 0 && vnode->lock_state != AFS_VNODE_LOCK_DELETED) {
+ trace_afs_flock_ev(vnode, NULL, afs_flock_release_fail,
+ ret);
printk(KERN_WARNING "AFS:"
" Failed to release lock on {%llx:%llx} error %d\n",
vnode->fid.vid, vnode->fid.vnode, ret);
-
- spin_lock(&vnode->lock);
- key_put(vnode->lock_key);
- vnode->lock_key = NULL;
- vnode->lock_state = AFS_VNODE_LOCK_NONE;
-
- if (list_empty(&vnode->pending_locks)) {
- spin_unlock(&vnode->lock);
- return;
}
- /* The new front of the queue now owns the state variables. */
- next = list_entry(vnode->pending_locks.next,
- struct file_lock, fl_u.afs.link);
- vnode->lock_key = key_get(afs_file_key(next->fl_file));
- vnode->lock_type = (next->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
- vnode->lock_state = AFS_VNODE_LOCK_WAITING_FOR_CB;
- goto again;
+ spin_lock(&vnode->lock);
+ if (ret == -ENOENT)
+ afs_kill_lockers_enoent(vnode);
+ else
+ afs_next_locker(vnode, 0);
+ spin_unlock(&vnode->lock);
+ return;
/* If we've already got a lock, then it must be time to extend that
* lock as AFS locks time out after 5 minutes.
ASSERT(!list_empty(&vnode->granted_locks));
key = key_get(vnode->lock_key);
- vnode->lock_state = AFS_VNODE_LOCK_EXTENDING;
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_EXTENDING);
+ trace_afs_flock_ev(vnode, NULL, afs_flock_work_extending, 0);
spin_unlock(&vnode->lock);
ret = afs_extend_lock(vnode, key); /* RPC */
key_put(key);
- if (ret < 0)
+ if (ret < 0) {
+ trace_afs_flock_ev(vnode, NULL, afs_flock_extend_fail,
+ ret);
pr_warning("AFS: Failed to extend lock on {%llx:%llx} error %d\n",
vnode->fid.vid, vnode->fid.vnode, ret);
+ }
spin_lock(&vnode->lock);
+ if (ret == -ENOENT) {
+ afs_kill_lockers_enoent(vnode);
+ spin_unlock(&vnode->lock);
+ return;
+ }
+
if (vnode->lock_state != AFS_VNODE_LOCK_EXTENDING)
goto again;
- vnode->lock_state = AFS_VNODE_LOCK_GRANTED;
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_GRANTED);
- if (ret == 0)
- afs_schedule_lock_extension(vnode);
- else
+ if (ret != 0)
queue_delayed_work(afs_lock_manager, &vnode->lock_work,
HZ * 10);
spin_unlock(&vnode->lock);
_leave(" [ext]");
return;
- /* If we don't have a granted lock, then we must've been called
- * back by the server, and so if might be possible to get a
- * lock we're currently waiting for.
- */
+ /* If we're waiting for a callback to indicate lock release, we can't
+ * actually rely on this, so need to recheck at regular intervals. The
+ * problem is that the server might not notify us if the lock just
+ * expires (say because a client died) rather than being explicitly
+ * released.
+ */
case AFS_VNODE_LOCK_WAITING_FOR_CB:
- _debug("get");
-
- key = key_get(vnode->lock_key);
- type = vnode->lock_type;
- vnode->lock_state = AFS_VNODE_LOCK_SETTING;
+ _debug("retry");
+ afs_next_locker(vnode, 0);
spin_unlock(&vnode->lock);
+ return;
- ret = afs_set_lock(vnode, key, type); /* RPC */
- key_put(key);
-
- spin_lock(&vnode->lock);
- switch (ret) {
- case -EWOULDBLOCK:
- _debug("blocked");
- break;
- case 0:
- _debug("acquired");
- vnode->lock_state = AFS_VNODE_LOCK_GRANTED;
- /* Fall through */
- default:
- /* Pass the lock or the error onto the first locker in
- * the list - if they're looking for this type of lock.
- * If they're not, we assume that whoever asked for it
- * took a signal.
- */
- if (list_empty(&vnode->pending_locks)) {
- _debug("withdrawn");
- vnode->lock_state = AFS_VNODE_LOCK_NEED_UNLOCK;
- goto again;
- }
-
- fl = list_entry(vnode->pending_locks.next,
- struct file_lock, fl_u.afs.link);
- type = (fl->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
- if (vnode->lock_type != type) {
- _debug("changed");
- vnode->lock_state = AFS_VNODE_LOCK_NEED_UNLOCK;
- goto again;
- }
-
- fl->fl_u.afs.state = ret;
- if (ret == 0)
- afs_grant_locks(vnode, fl);
- else
- list_del_init(&fl->fl_u.afs.link);
- wake_up(&fl->fl_wait);
- spin_unlock(&vnode->lock);
- _leave(" [granted]");
- return;
- }
+ case AFS_VNODE_LOCK_DELETED:
+ afs_kill_lockers_enoent(vnode);
+ spin_unlock(&vnode->lock);
+ return;
+ /* Fall through */
default:
/* Looks like a lock request was withdrawn. */
spin_unlock(&vnode->lock);
*/
static void afs_defer_unlock(struct afs_vnode *vnode)
{
- _enter("");
+ _enter("%u", vnode->lock_state);
- if (vnode->lock_state == AFS_VNODE_LOCK_GRANTED ||
- vnode->lock_state == AFS_VNODE_LOCK_EXTENDING) {
+ if (list_empty(&vnode->granted_locks) &&
+ (vnode->lock_state == AFS_VNODE_LOCK_GRANTED ||
+ vnode->lock_state == AFS_VNODE_LOCK_EXTENDING)) {
cancel_delayed_work(&vnode->lock_work);
- vnode->lock_state = AFS_VNODE_LOCK_NEED_UNLOCK;
- afs_lock_may_be_available(vnode);
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_NEED_UNLOCK);
+ trace_afs_flock_ev(vnode, NULL, afs_flock_defer_unlock, 0);
+ queue_delayed_work(afs_lock_manager, &vnode->lock_work, 0);
}
}
* whether we think that we have a locking permit.
*/
static int afs_do_setlk_check(struct afs_vnode *vnode, struct key *key,
- afs_lock_type_t type, bool can_sleep)
+ enum afs_flock_mode mode, afs_lock_type_t type)
{
afs_access_t access;
int ret;
if (type == AFS_LOCK_READ) {
if (!(access & (AFS_ACE_INSERT | AFS_ACE_WRITE | AFS_ACE_LOCK)))
return -EACCES;
- if (vnode->status.lock_count == -1 && !can_sleep)
- return -EAGAIN; /* Write locked */
} else {
if (!(access & (AFS_ACE_INSERT | AFS_ACE_WRITE)))
return -EACCES;
- if (vnode->status.lock_count != 0 && !can_sleep)
- return -EAGAIN; /* Locked */
}
return 0;
}
-/*
- * Remove the front runner from the pending queue.
- * - The caller must hold vnode->lock.
- */
-static void afs_dequeue_lock(struct afs_vnode *vnode, struct file_lock *fl)
-{
- struct file_lock *next;
-
- _enter("");
-
- /* ->lock_type, ->lock_key and ->lock_state only belong to this
- * file_lock if we're at the front of the pending queue or if we have
- * the lock granted or if the lock_state is NEED_UNLOCK or UNLOCKING.
- */
- if (vnode->granted_locks.next == &fl->fl_u.afs.link &&
- vnode->granted_locks.prev == &fl->fl_u.afs.link) {
- list_del_init(&fl->fl_u.afs.link);
- afs_defer_unlock(vnode);
- return;
- }
-
- if (!list_empty(&vnode->granted_locks) ||
- vnode->pending_locks.next != &fl->fl_u.afs.link) {
- list_del_init(&fl->fl_u.afs.link);
- return;
- }
-
- list_del_init(&fl->fl_u.afs.link);
- key_put(vnode->lock_key);
- vnode->lock_key = NULL;
- vnode->lock_state = AFS_VNODE_LOCK_NONE;
-
- if (list_empty(&vnode->pending_locks))
- return;
-
- /* The new front of the queue now owns the state variables. */
- next = list_entry(vnode->pending_locks.next,
- struct file_lock, fl_u.afs.link);
- vnode->lock_key = key_get(afs_file_key(next->fl_file));
- vnode->lock_type = (next->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
- vnode->lock_state = AFS_VNODE_LOCK_WAITING_FOR_CB;
- afs_lock_may_be_available(vnode);
-}
-
/*
* request a lock on a file on the server
*/
{
struct inode *inode = locks_inode(file);
struct afs_vnode *vnode = AFS_FS_I(inode);
+ enum afs_flock_mode mode = AFS_FS_S(inode->i_sb)->flock_mode;
afs_lock_type_t type;
struct key *key = afs_file_key(file);
+ bool partial, no_server_lock = false;
int ret;
- _enter("{%llx:%llu},%u", vnode->fid.vid, vnode->fid.vnode, fl->fl_type);
+ if (mode == afs_flock_mode_unset)
+ mode = afs_flock_mode_openafs;
- /* only whole-file locks are supported */
- if (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX)
- return -EINVAL;
+ _enter("{%llx:%llu},%llu-%llu,%u,%u",
+ vnode->fid.vid, vnode->fid.vnode,
+ fl->fl_start, fl->fl_end, fl->fl_type, mode);
fl->fl_ops = &afs_lock_ops;
INIT_LIST_HEAD(&fl->fl_u.afs.link);
fl->fl_u.afs.state = AFS_LOCK_PENDING;
+ partial = (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX);
type = (fl->fl_type == F_RDLCK) ? AFS_LOCK_READ : AFS_LOCK_WRITE;
+ if (mode == afs_flock_mode_write && partial)
+ type = AFS_LOCK_WRITE;
- ret = afs_do_setlk_check(vnode, key, type, fl->fl_flags & FL_SLEEP);
+ ret = afs_do_setlk_check(vnode, key, mode, type);
if (ret < 0)
return ret;
- spin_lock(&vnode->lock);
+ trace_afs_flock_op(vnode, fl, afs_flock_op_set_lock);
- /* If we've already got a readlock on the server then we instantly
- * grant another readlock, irrespective of whether there are any
- * pending writelocks.
+ /* AFS3 protocol only supports full-file locks and doesn't provide any
+ * method of upgrade/downgrade, so we need to emulate for partial-file
+ * locks.
+ *
+ * The OpenAFS client only gets a server lock for a full-file lock and
+ * keeps partial-file locks local. Allow this behaviour to be emulated
+ * (as the default).
*/
- if (type == AFS_LOCK_READ &&
- vnode->lock_state == AFS_VNODE_LOCK_GRANTED &&
- vnode->lock_type == AFS_LOCK_READ) {
- _debug("instant readlock");
- ASSERT(!list_empty(&vnode->granted_locks));
- goto share_existing_lock;
+ if (mode == afs_flock_mode_local ||
+ (partial && mode == afs_flock_mode_openafs)) {
+ no_server_lock = true;
+ goto skip_server_lock;
}
+ spin_lock(&vnode->lock);
list_add_tail(&fl->fl_u.afs.link, &vnode->pending_locks);
+ ret = -ENOENT;
+ if (vnode->lock_state == AFS_VNODE_LOCK_DELETED)
+ goto error_unlock;
+
+ /* If we've already got a lock on the server then try to move to having
+ * the VFS grant the requested lock. Note that this means that other
+ * clients may get starved out.
+ */
+ _debug("try %u", vnode->lock_state);
+ if (vnode->lock_state == AFS_VNODE_LOCK_GRANTED) {
+ if (type == AFS_LOCK_READ) {
+ _debug("instant readlock");
+ list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
+ fl->fl_u.afs.state = AFS_LOCK_GRANTED;
+ goto vnode_is_locked_u;
+ }
+
+ if (vnode->lock_type == AFS_LOCK_WRITE) {
+ _debug("instant writelock");
+ list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
+ fl->fl_u.afs.state = AFS_LOCK_GRANTED;
+ goto vnode_is_locked_u;
+ }
+ }
+
+ if (vnode->lock_state == AFS_VNODE_LOCK_NONE &&
+ !(fl->fl_flags & FL_SLEEP)) {
+ ret = -EAGAIN;
+ if (type == AFS_LOCK_READ) {
+ if (vnode->status.lock_count == -1)
+ goto lock_is_contended; /* Write locked */
+ } else {
+ if (vnode->status.lock_count != 0)
+ goto lock_is_contended; /* Locked */
+ }
+ }
+
if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
goto need_to_wait;
+try_to_lock:
/* We don't have a lock on this vnode and we aren't currently waiting
* for one either, so ask the server for a lock.
*
* Note that we need to be careful if we get interrupted by a signal
* after dispatching the request as we may still get the lock, even
* though we don't wait for the reply (it's not too bad a problem - the
- * lock will expire in 10 mins anyway).
+ * lock will expire in 5 mins anyway).
*/
- _debug("not locked");
+ trace_afs_flock_ev(vnode, fl, afs_flock_try_to_lock, 0);
vnode->lock_key = key_get(key);
vnode->lock_type = type;
- vnode->lock_state = AFS_VNODE_LOCK_SETTING;
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING);
spin_unlock(&vnode->lock);
ret = afs_set_lock(vnode, key, type); /* RPC */
spin_lock(&vnode->lock);
switch (ret) {
+ case -EKEYREJECTED:
+ case -EKEYEXPIRED:
+ case -EKEYREVOKED:
+ case -EPERM:
+ case -EACCES:
+ fl->fl_u.afs.state = ret;
+ trace_afs_flock_ev(vnode, fl, afs_flock_fail_perm, ret);
+ list_del_init(&fl->fl_u.afs.link);
+ afs_next_locker(vnode, ret);
+ goto error_unlock;
+
+ case -ENOENT:
+ fl->fl_u.afs.state = ret;
+ trace_afs_flock_ev(vnode, fl, afs_flock_fail_other, ret);
+ list_del_init(&fl->fl_u.afs.link);
+ afs_kill_lockers_enoent(vnode);
+ goto error_unlock;
+
default:
- goto abort_attempt;
+ fl->fl_u.afs.state = ret;
+ trace_afs_flock_ev(vnode, fl, afs_flock_fail_other, ret);
+ list_del_init(&fl->fl_u.afs.link);
+ afs_next_locker(vnode, 0);
+ goto error_unlock;
case -EWOULDBLOCK:
/* The server doesn't have a lock-waiting queue, so the client
* will have to retry. The server will break the outstanding
* callbacks on a file when a lock is released.
*/
- _debug("would block");
ASSERT(list_empty(&vnode->granted_locks));
ASSERTCMP(vnode->pending_locks.next, ==, &fl->fl_u.afs.link);
- vnode->lock_state = AFS_VNODE_LOCK_WAITING_FOR_CB;
- goto need_to_wait;
+ goto lock_is_contended;
case 0:
- _debug("acquired");
- break;
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_GRANTED);
+ trace_afs_flock_ev(vnode, fl, afs_flock_acquired, type);
+ afs_grant_locks(vnode);
+ goto vnode_is_locked_u;
}
- /* we've acquired a server lock, but it needs to be renewed after 5
- * mins */
- vnode->lock_state = AFS_VNODE_LOCK_GRANTED;
- afs_schedule_lock_extension(vnode);
-
-share_existing_lock:
- /* the lock has been granted as far as we're concerned... */
- fl->fl_u.afs.state = AFS_LOCK_GRANTED;
- list_move_tail(&fl->fl_u.afs.link, &vnode->granted_locks);
-
-given_lock:
- /* ... but we do still need to get the VFS's blessing */
+vnode_is_locked_u:
spin_unlock(&vnode->lock);
-
- ret = posix_lock_file(file, fl, NULL);
+vnode_is_locked:
+ /* the lock has been granted by the server... */
+ ASSERTCMP(fl->fl_u.afs.state, ==, AFS_LOCK_GRANTED);
+
+skip_server_lock:
+ /* ... but the VFS still needs to distribute access on this client. */
+ trace_afs_flock_ev(vnode, fl, afs_flock_vfs_locking, 0);
+ ret = locks_lock_file_wait(file, fl);
+ trace_afs_flock_ev(vnode, fl, afs_flock_vfs_lock, ret);
if (ret < 0)
goto vfs_rejected_lock;
_leave(" = 0");
return 0;
+lock_is_contended:
+ if (!(fl->fl_flags & FL_SLEEP)) {
+ list_del_init(&fl->fl_u.afs.link);
+ afs_next_locker(vnode, 0);
+ ret = -EAGAIN;
+ goto error_unlock;
+ }
+
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_WAITING_FOR_CB);
+ trace_afs_flock_ev(vnode, fl, afs_flock_would_block, ret);
+ queue_delayed_work(afs_lock_manager, &vnode->lock_work, HZ * 5);
+
need_to_wait:
/* We're going to have to wait. Either this client doesn't have a lock
* on the server yet and we need to wait for a callback to occur, or
- * the client does have a lock on the server, but it belongs to some
- * other process(es) and is incompatible with the lock we want.
+ * the client does have a lock on the server, but it's shared and we
+ * need an exclusive lock.
*/
- ret = -EAGAIN;
- if (fl->fl_flags & FL_SLEEP) {
- spin_unlock(&vnode->lock);
+ spin_unlock(&vnode->lock);
- _debug("sleep");
- ret = wait_event_interruptible(fl->fl_wait,
- fl->fl_u.afs.state != AFS_LOCK_PENDING);
+ trace_afs_flock_ev(vnode, fl, afs_flock_waiting, 0);
+ ret = wait_event_interruptible(fl->fl_wait,
+ fl->fl_u.afs.state != AFS_LOCK_PENDING);
+ trace_afs_flock_ev(vnode, fl, afs_flock_waited, ret);
+ if (fl->fl_u.afs.state >= 0 && fl->fl_u.afs.state != AFS_LOCK_GRANTED) {
spin_lock(&vnode->lock);
- }
- if (fl->fl_u.afs.state == AFS_LOCK_GRANTED)
- goto given_lock;
- if (fl->fl_u.afs.state < 0)
- ret = fl->fl_u.afs.state;
+ switch (fl->fl_u.afs.state) {
+ case AFS_LOCK_YOUR_TRY:
+ fl->fl_u.afs.state = AFS_LOCK_PENDING;
+ goto try_to_lock;
+ case AFS_LOCK_PENDING:
+ if (ret > 0) {
+ /* We need to retry the lock. We may not be
+ * notified by the server if it just expired
+ * rather than being released.
+ */
+ ASSERTCMP(vnode->lock_state, ==, AFS_VNODE_LOCK_WAITING_FOR_CB);
+ afs_set_lock_state(vnode, AFS_VNODE_LOCK_SETTING);
+ fl->fl_u.afs.state = AFS_LOCK_PENDING;
+ goto try_to_lock;
+ }
+ goto error_unlock;
+ case AFS_LOCK_GRANTED:
+ default:
+ break;
+ }
-abort_attempt:
- /* we aren't going to get the lock, either because we're unwilling to
- * wait, or because some signal happened */
- _debug("abort");
- afs_dequeue_lock(vnode, fl);
+ spin_unlock(&vnode->lock);
+ }
-error_unlock:
- spin_unlock(&vnode->lock);
- _leave(" = %d", ret);
- return ret;
+ if (fl->fl_u.afs.state == AFS_LOCK_GRANTED)
+ goto vnode_is_locked;
+ ret = fl->fl_u.afs.state;
+ goto error;
vfs_rejected_lock:
/* The VFS rejected the lock we just obtained, so we have to discard
* deal with.
*/
_debug("vfs refused %d", ret);
+ if (no_server_lock)
+ goto error;
spin_lock(&vnode->lock);
list_del_init(&fl->fl_u.afs.link);
- if (list_empty(&vnode->granted_locks))
- afs_defer_unlock(vnode);
- goto error_unlock;
+ afs_defer_unlock(vnode);
+
+error_unlock:
+ spin_unlock(&vnode->lock);
+error:
+ _leave(" = %d", ret);
+ return ret;
}
/*
_enter("{%llx:%llu},%u", vnode->fid.vid, vnode->fid.vnode, fl->fl_type);
+ trace_afs_flock_op(vnode, fl, afs_flock_op_unlock);
+
/* Flush all pending writes before doing anything with locks. */
vfs_fsync(file, 0);
- /* only whole-file unlocks are supported */
- if (fl->fl_start != 0 || fl->fl_end != OFFSET_MAX)
- return -EINVAL;
-
- ret = posix_lock_file(file, fl, NULL);
+ ret = locks_lock_file_wait(file, fl);
_leave(" = %d [%u]", ret, vnode->lock_state);
return ret;
}
_enter("");
+ if (vnode->lock_state == AFS_VNODE_LOCK_DELETED)
+ return -ENOENT;
+
fl->fl_type = F_UNLCK;
/* check local lock records first */
goto error;
lock_count = READ_ONCE(vnode->status.lock_count);
- if (lock_count > 0)
- fl->fl_type = F_RDLCK;
- else
- fl->fl_type = F_WRLCK;
- fl->fl_start = 0;
- fl->fl_end = OFFSET_MAX;
+ if (lock_count != 0) {
+ if (lock_count > 0)
+ fl->fl_type = F_RDLCK;
+ else
+ fl->fl_type = F_WRLCK;
+ fl->fl_start = 0;
+ fl->fl_end = OFFSET_MAX;
+ fl->fl_pid = 0;
+ }
}
ret = 0;
int afs_lock(struct file *file, int cmd, struct file_lock *fl)
{
struct afs_vnode *vnode = AFS_FS_I(locks_inode(file));
+ enum afs_flock_operation op;
+ int ret;
_enter("{%llx:%llu},%d,{t=%x,fl=%x,r=%Ld:%Ld}",
vnode->fid.vid, vnode->fid.vnode, cmd,
if (IS_GETLK(cmd))
return afs_do_getlk(file, fl);
+
+ fl->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id);
+ trace_afs_flock_op(vnode, fl, afs_flock_op_lock);
+
if (fl->fl_type == F_UNLCK)
- return afs_do_unlk(file, fl);
- return afs_do_setlk(file, fl);
+ ret = afs_do_unlk(file, fl);
+ else
+ ret = afs_do_setlk(file, fl);
+
+ switch (ret) {
+ case 0: op = afs_flock_op_return_ok; break;
+ case -EAGAIN: op = afs_flock_op_return_eagain; break;
+ case -EDEADLK: op = afs_flock_op_return_edeadlk; break;
+ default: op = afs_flock_op_return_error; break;
+ }
+ trace_afs_flock_op(vnode, fl, op);
+ return ret;
}
/*
int afs_flock(struct file *file, int cmd, struct file_lock *fl)
{
struct afs_vnode *vnode = AFS_FS_I(locks_inode(file));
+ enum afs_flock_operation op;
+ int ret;
_enter("{%llx:%llu},%d,{t=%x,fl=%x}",
vnode->fid.vid, vnode->fid.vnode, cmd,
if (!(fl->fl_flags & FL_FLOCK))
return -ENOLCK;
+ fl->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id);
+ trace_afs_flock_op(vnode, fl, afs_flock_op_flock);
+
/* we're simulating flock() locks using posix locks on the server */
if (fl->fl_type == F_UNLCK)
- return afs_do_unlk(file, fl);
- return afs_do_setlk(file, fl);
+ ret = afs_do_unlk(file, fl);
+ else
+ ret = afs_do_setlk(file, fl);
+
+ switch (ret) {
+ case 0: op = afs_flock_op_return_ok; break;
+ case -EAGAIN: op = afs_flock_op_return_eagain; break;
+ case -EDEADLK: op = afs_flock_op_return_edeadlk; break;
+ default: op = afs_flock_op_return_error; break;
+ }
+ trace_afs_flock_op(vnode, fl, op);
+ return ret;
}
/*
_enter("");
+ new->fl_u.afs.debug_id = atomic_inc_return(&afs_file_lock_debug_id);
+
spin_lock(&vnode->lock);
+ trace_afs_flock_op(vnode, new, afs_flock_op_copy_lock);
list_add(&new->fl_u.afs.link, &fl->fl_u.afs.link);
spin_unlock(&vnode->lock);
}
_enter("");
spin_lock(&vnode->lock);
- afs_dequeue_lock(vnode, fl);
+
+ trace_afs_flock_op(vnode, fl, afs_flock_op_release_lock);
+ list_del_init(&fl->fl_u.afs.link);
+ if (list_empty(&vnode->granted_locks))
+ afs_defer_unlock(vnode);
+
_debug("state %u for %p", vnode->lock_state, vnode);
spin_unlock(&vnode->lock);
}
projects / linux-2.6-microblaze.git / blobdiff