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-rw-r--r--fs/dlm/ast.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
new file mode 100644
index 000000000..dcea1e37a
--- /dev/null
+++ b/fs/dlm/ast.c
@@ -0,0 +1,314 @@
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+** Copyright (C) 2004-2010 Red Hat, Inc. All rights reserved.
+**
+** This copyrighted material is made available to anyone wishing to use,
+** modify, copy, or redistribute it subject to the terms and conditions
+** of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+#include "dlm_internal.h"
+#include "lock.h"
+#include "user.h"
+#include "ast.h"
+
+static uint64_t dlm_cb_seq;
+static DEFINE_SPINLOCK(dlm_cb_seq_spin);
+
+static void dlm_dump_lkb_callbacks(struct dlm_lkb *lkb)
+{
+ int i;
+
+ log_print("last_bast %x %llu flags %x mode %d sb %d %x",
+ lkb->lkb_id,
+ (unsigned long long)lkb->lkb_last_bast.seq,
+ lkb->lkb_last_bast.flags,
+ lkb->lkb_last_bast.mode,
+ lkb->lkb_last_bast.sb_status,
+ lkb->lkb_last_bast.sb_flags);
+
+ log_print("last_cast %x %llu flags %x mode %d sb %d %x",
+ lkb->lkb_id,
+ (unsigned long long)lkb->lkb_last_cast.seq,
+ lkb->lkb_last_cast.flags,
+ lkb->lkb_last_cast.mode,
+ lkb->lkb_last_cast.sb_status,
+ lkb->lkb_last_cast.sb_flags);
+
+ for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
+ log_print("cb %x %llu flags %x mode %d sb %d %x",
+ lkb->lkb_id,
+ (unsigned long long)lkb->lkb_callbacks[i].seq,
+ lkb->lkb_callbacks[i].flags,
+ lkb->lkb_callbacks[i].mode,
+ lkb->lkb_callbacks[i].sb_status,
+ lkb->lkb_callbacks[i].sb_flags);
+ }
+}
+
+int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
+ int status, uint32_t sbflags, uint64_t seq)
+{
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ uint64_t prev_seq;
+ int prev_mode;
+ int i, rv;
+
+ for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
+ if (lkb->lkb_callbacks[i].seq)
+ continue;
+
+ /*
+ * Suppress some redundant basts here, do more on removal.
+ * Don't even add a bast if the callback just before it
+ * is a bast for the same mode or a more restrictive mode.
+ * (the addional > PR check is needed for PR/CW inversion)
+ */
+
+ if ((i > 0) && (flags & DLM_CB_BAST) &&
+ (lkb->lkb_callbacks[i-1].flags & DLM_CB_BAST)) {
+
+ prev_seq = lkb->lkb_callbacks[i-1].seq;
+ prev_mode = lkb->lkb_callbacks[i-1].mode;
+
+ if ((prev_mode == mode) ||
+ (prev_mode > mode && prev_mode > DLM_LOCK_PR)) {
+
+ log_debug(ls, "skip %x add bast %llu mode %d "
+ "for bast %llu mode %d",
+ lkb->lkb_id,
+ (unsigned long long)seq,
+ mode,
+ (unsigned long long)prev_seq,
+ prev_mode);
+ rv = 0;
+ goto out;
+ }
+ }
+
+ lkb->lkb_callbacks[i].seq = seq;
+ lkb->lkb_callbacks[i].flags = flags;
+ lkb->lkb_callbacks[i].mode = mode;
+ lkb->lkb_callbacks[i].sb_status = status;
+ lkb->lkb_callbacks[i].sb_flags = (sbflags & 0x000000FF);
+ rv = 0;
+ break;
+ }
+
+ if (i == DLM_CALLBACKS_SIZE) {
+ log_error(ls, "no callbacks %x %llu flags %x mode %d sb %d %x",
+ lkb->lkb_id, (unsigned long long)seq,
+ flags, mode, status, sbflags);
+ dlm_dump_lkb_callbacks(lkb);
+ rv = -1;
+ goto out;
+ }
+ out:
+ return rv;
+}
+
+int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_callback *cb, int *resid)
+{
+ int i, rv;
+
+ *resid = 0;
+
+ if (!lkb->lkb_callbacks[0].seq) {
+ rv = -ENOENT;
+ goto out;
+ }
+
+ /* oldest undelivered cb is callbacks[0] */
+
+ memcpy(cb, &lkb->lkb_callbacks[0], sizeof(struct dlm_callback));
+ memset(&lkb->lkb_callbacks[0], 0, sizeof(struct dlm_callback));
+
+ /* shift others down */
+
+ for (i = 1; i < DLM_CALLBACKS_SIZE; i++) {
+ if (!lkb->lkb_callbacks[i].seq)
+ break;
+ memcpy(&lkb->lkb_callbacks[i-1], &lkb->lkb_callbacks[i],
+ sizeof(struct dlm_callback));
+ memset(&lkb->lkb_callbacks[i], 0, sizeof(struct dlm_callback));
+ (*resid)++;
+ }
+
+ /* if cb is a bast, it should be skipped if the blocking mode is
+ compatible with the last granted mode */
+
+ if ((cb->flags & DLM_CB_BAST) && lkb->lkb_last_cast.seq) {
+ if (dlm_modes_compat(cb->mode, lkb->lkb_last_cast.mode)) {
+ cb->flags |= DLM_CB_SKIP;
+
+ log_debug(ls, "skip %x bast %llu mode %d "
+ "for cast %llu mode %d",
+ lkb->lkb_id,
+ (unsigned long long)cb->seq,
+ cb->mode,
+ (unsigned long long)lkb->lkb_last_cast.seq,
+ lkb->lkb_last_cast.mode);
+ rv = 0;
+ goto out;
+ }
+ }
+
+ if (cb->flags & DLM_CB_CAST) {
+ memcpy(&lkb->lkb_last_cast, cb, sizeof(struct dlm_callback));
+ lkb->lkb_last_cast_time = ktime_get();
+ }
+
+ if (cb->flags & DLM_CB_BAST) {
+ memcpy(&lkb->lkb_last_bast, cb, sizeof(struct dlm_callback));
+ lkb->lkb_last_bast_time = ktime_get();
+ }
+ rv = 0;
+ out:
+ return rv;
+}
+
+void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
+ uint32_t sbflags)
+{
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ uint64_t new_seq, prev_seq;
+ int rv;
+
+ spin_lock(&dlm_cb_seq_spin);
+ new_seq = ++dlm_cb_seq;
+ spin_unlock(&dlm_cb_seq_spin);
+
+ if (lkb->lkb_flags & DLM_IFL_USER) {
+ dlm_user_add_ast(lkb, flags, mode, status, sbflags, new_seq);
+ return;
+ }
+
+ mutex_lock(&lkb->lkb_cb_mutex);
+ prev_seq = lkb->lkb_callbacks[0].seq;
+
+ rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, new_seq);
+ if (rv < 0)
+ goto out;
+
+ if (!prev_seq) {
+ kref_get(&lkb->lkb_ref);
+
+ if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
+ mutex_lock(&ls->ls_cb_mutex);
+ list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
+ mutex_unlock(&ls->ls_cb_mutex);
+ } else {
+ queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
+ }
+ }
+ out:
+ mutex_unlock(&lkb->lkb_cb_mutex);
+}
+
+void dlm_callback_work(struct work_struct *work)
+{
+ struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work);
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ void (*castfn) (void *astparam);
+ void (*bastfn) (void *astparam, int mode);
+ struct dlm_callback callbacks[DLM_CALLBACKS_SIZE];
+ int i, rv, resid;
+
+ memset(&callbacks, 0, sizeof(callbacks));
+
+ mutex_lock(&lkb->lkb_cb_mutex);
+ if (!lkb->lkb_callbacks[0].seq) {
+ /* no callback work exists, shouldn't happen */
+ log_error(ls, "dlm_callback_work %x no work", lkb->lkb_id);
+ dlm_print_lkb(lkb);
+ dlm_dump_lkb_callbacks(lkb);
+ }
+
+ for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
+ rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid);
+ if (rv < 0)
+ break;
+ }
+
+ if (resid) {
+ /* cbs remain, loop should have removed all, shouldn't happen */
+ log_error(ls, "dlm_callback_work %x resid %d", lkb->lkb_id,
+ resid);
+ dlm_print_lkb(lkb);
+ dlm_dump_lkb_callbacks(lkb);
+ }
+ mutex_unlock(&lkb->lkb_cb_mutex);
+
+ castfn = lkb->lkb_astfn;
+ bastfn = lkb->lkb_bastfn;
+
+ for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
+ if (!callbacks[i].seq)
+ break;
+ if (callbacks[i].flags & DLM_CB_SKIP) {
+ continue;
+ } else if (callbacks[i].flags & DLM_CB_BAST) {
+ bastfn(lkb->lkb_astparam, callbacks[i].mode);
+ } else if (callbacks[i].flags & DLM_CB_CAST) {
+ lkb->lkb_lksb->sb_status = callbacks[i].sb_status;
+ lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags;
+ castfn(lkb->lkb_astparam);
+ }
+ }
+
+ /* undo kref_get from dlm_add_callback, may cause lkb to be freed */
+ dlm_put_lkb(lkb);
+}
+
+int dlm_callback_start(struct dlm_ls *ls)
+{
+ ls->ls_callback_wq = alloc_workqueue("dlm_callback",
+ WQ_UNBOUND | WQ_MEM_RECLAIM, 0);
+ if (!ls->ls_callback_wq) {
+ log_print("can't start dlm_callback workqueue");
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+void dlm_callback_stop(struct dlm_ls *ls)
+{
+ if (ls->ls_callback_wq)
+ destroy_workqueue(ls->ls_callback_wq);
+}
+
+void dlm_callback_suspend(struct dlm_ls *ls)
+{
+ set_bit(LSFL_CB_DELAY, &ls->ls_flags);
+
+ if (ls->ls_callback_wq)
+ flush_workqueue(ls->ls_callback_wq);
+}
+
+void dlm_callback_resume(struct dlm_ls *ls)
+{
+ struct dlm_lkb *lkb, *safe;
+ int count = 0;
+
+ clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
+
+ if (!ls->ls_callback_wq)
+ return;
+
+ mutex_lock(&ls->ls_cb_mutex);
+ list_for_each_entry_safe(lkb, safe, &ls->ls_cb_delay, lkb_cb_list) {
+ list_del_init(&lkb->lkb_cb_list);
+ queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
+ count++;
+ }
+ mutex_unlock(&ls->ls_cb_mutex);
+
+ if (count)
+ log_rinfo(ls, "dlm_callback_resume %d", count);
+}
+
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-14 12:49:58 +0000