Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus-1

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits)
  [media] rc: update for bitop name changes
  fs: simplify iget & friends
  fs: pull inode->i_lock up out of writeback_single_inode
  fs: rename inode_lock to inode_hash_lock
  fs: move i_wb_list out from under inode_lock
  fs: move i_sb_list out from under inode_lock
  fs: remove inode_lock from iput_final and prune_icache
  fs: Lock the inode LRU list separately
  fs: factor inode disposal
  fs: protect inode->i_state with inode->i_lock
  lib, arch: add filter argument to show_mem and fix private implementations
  SLUB: Write to per cpu data when allocating it
  slub: Fix debugobjects with lockless fastpath
  autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
  autofs4 - remove autofs4_lock
  autofs4 - fix d_manage() return on rcu-walk
  autofs4 - fix autofs4_expire_indirect() traversal
  autofs4 - fix dentry leak in autofs4_expire_direct()
  autofs4 - reinstate last used update on access
  vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
  ...

NOTE!

This merge commit was created to fix compilation error. The block
tree was merged upstream and removed the 'elv_queue_empty()'
function which the new 'mtdswap' driver is using. So a simple
merge of the mtd tree with upstream does not compile. And the
mtd tree has already be published, so re-basing it is not an option.

To fix this unfortunate situation, I had to merge upstream into the
mtd-2.6.git tree without committing, put the fixup patch on top of
this, and then commit this. The result is that we do not have commits
which do not compile.

In other words, this merge commit "merges" 3 things: the MTD tree, the
upstream tree, and the fixup patch.

1 files changed, 198 insertions, 59 deletions

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 4314f0d48d85..abc49f292454 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();