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-rw-r--r--fs/dlm/ast.c257
1 files changed, 198 insertions, 59 deletions
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 4314f0d..abc49f2 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -18,6 +18,7 @@
#define WAKE_ASTS 0
+static uint64_t ast_seq_count;
static struct list_head ast_queue;
static spinlock_t ast_queue_lock;
static struct task_struct * astd_task;
@@ -25,40 +26,186 @@ static unsigned long astd_wakeflags;
static struct mutex astd_running;
+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);
+ }
+}
+
void dlm_del_ast(struct dlm_lkb *lkb)
{
spin_lock(&ast_queue_lock);
- if (lkb->lkb_ast_type & (AST_COMP | AST_BAST))
- list_del(&lkb->lkb_astqueue);
+ if (!list_empty(&lkb->lkb_astqueue))
+ list_del_init(&lkb->lkb_astqueue);
spin_unlock(&ast_queue_lock);
}
-void dlm_add_ast(struct dlm_lkb *lkb, int type, int mode)
+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;
+
+ 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);
+ return 0;
+ }
+ }
+
+ 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);
+ 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);
+ return -1;
+ }
+
+ return 0;
+}
+
+int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_callback *cb, int *resid)
+{
+ int i;
+
+ *resid = 0;
+
+ if (!lkb->lkb_callbacks[0].seq)
+ return -ENOENT;
+
+ /* 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);
+ return 0;
+ }
+ }
+
+ 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();
+ }
+
+ return 0;
+}
+
+void dlm_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
+ uint32_t sbflags)
+{
+ uint64_t seq;
+ int rv;
+
+ spin_lock(&ast_queue_lock);
+
+ seq = ++ast_seq_count;
+
if (lkb->lkb_flags & DLM_IFL_USER) {
- dlm_user_add_ast(lkb, type, mode);
+ spin_unlock(&ast_queue_lock);
+ dlm_user_add_ast(lkb, flags, mode, status, sbflags, seq);
return;
}
- spin_lock(&ast_queue_lock);
- if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) {
+ rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, seq);
+ if (rv < 0) {
+ spin_unlock(&ast_queue_lock);
+ return;
+ }
+
+ if (list_empty(&lkb->lkb_astqueue)) {
kref_get(&lkb->lkb_ref);
list_add_tail(&lkb->lkb_astqueue, &ast_queue);
- lkb->lkb_ast_first = type;
}
-
- /* sanity check, this should not happen */
-
- if ((type == AST_COMP) && (lkb->lkb_ast_type & AST_COMP))
- log_print("repeat cast %d castmode %d lock %x %s",
- mode, lkb->lkb_castmode,
- lkb->lkb_id, lkb->lkb_resource->res_name);
-
- lkb->lkb_ast_type |= type;
- if (type == AST_BAST)
- lkb->lkb_bastmode = mode;
- else
- lkb->lkb_castmode = mode;
spin_unlock(&ast_queue_lock);
set_bit(WAKE_ASTS, &astd_wakeflags);
@@ -72,7 +219,8 @@ static void process_asts(void)
struct dlm_lkb *lkb;
void (*castfn) (void *astparam);
void (*bastfn) (void *astparam, int mode);
- int type, first, bastmode, castmode, do_bast, do_cast, last_castmode;
+ struct dlm_callback callbacks[DLM_CALLBACKS_SIZE];
+ int i, rv, resid;
repeat:
spin_lock(&ast_queue_lock);
@@ -83,54 +231,45 @@ repeat:
if (dlm_locking_stopped(ls))
continue;
- list_del(&lkb->lkb_astqueue);
- type = lkb->lkb_ast_type;
- lkb->lkb_ast_type = 0;
- first = lkb->lkb_ast_first;
- lkb->lkb_ast_first = 0;
- bastmode = lkb->lkb_bastmode;
- castmode = lkb->lkb_castmode;
+ /* we remove from astqueue list and remove everything in
+ lkb_callbacks before releasing the spinlock so empty
+ lkb_astqueue is always consistent with empty lkb_callbacks */
+
+ list_del_init(&lkb->lkb_astqueue);
+
castfn = lkb->lkb_astfn;
bastfn = lkb->lkb_bastfn;
- spin_unlock(&ast_queue_lock);
- do_cast = (type & AST_COMP) && castfn;
- do_bast = (type & AST_BAST) && bastfn;
+ memset(&callbacks, 0, sizeof(callbacks));
- /* Skip a bast if its blocking mode is compatible with the
- granted mode of the preceding cast. */
+ for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
+ rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid);
+ if (rv < 0)
+ break;
+ }
+ spin_unlock(&ast_queue_lock);
- if (do_bast) {
- if (first == AST_COMP)
- last_castmode = castmode;
- else
- last_castmode = lkb->lkb_castmode_done;
- if (dlm_modes_compat(bastmode, last_castmode))
- do_bast = 0;
+ if (resid) {
+ /* shouldn't happen, for loop should have removed all */
+ log_error(ls, "callback resid %d lkb %x",
+ resid, lkb->lkb_id);
}
- if (first == AST_COMP) {
- if (do_cast)
- castfn(lkb->lkb_astparam);
- if (do_bast)
- bastfn(lkb->lkb_astparam, bastmode);
- } else if (first == AST_BAST) {
- if (do_bast)
- bastfn(lkb->lkb_astparam, bastmode);
- if (do_cast)
+ 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);
- } else {
- log_error(ls, "bad ast_first %d ast_type %d",
- first, type);
+ }
}
- if (do_cast)
- lkb->lkb_castmode_done = castmode;
- if (do_bast)
- lkb->lkb_bastmode_done = bastmode;
-
- /* this removes the reference added by dlm_add_ast
- and may result in the lkb being freed */
+ /* removes ref for ast_queue, may cause lkb to be freed */
dlm_put_lkb(lkb);
cond_resched();