Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: Don't count_vm_events for discard bio in submit_bio.
  cfq: fix recursive call in cfq_blkiocg_update_completion_stats()
  cfq-iosched: Fixed boot warning with BLK_CGROUP=y and CFQ_GROUP_IOSCHED=n
  cfq: Don't allow queue merges for queues that have no process references
  block: fix DISCARD_BARRIER requests
  cciss: set SCSI max cmd len to 16, as default is wrong
  cpqarray: fix two more wrong section type
  cpqarray: fix wrong __init type on pci probe function
  drbd: Fixed a race between disk-attach and unexpected state changes
  writeback: fix pin_sb_for_writeback
  writeback: add missing requeue_io in writeback_inodes_wb
  writeback: simplify and split bdi_start_writeback
  writeback: simplify wakeup_flusher_threads
  writeback: fix writeback_inodes_wb from writeback_inodes_sb
  writeback: enforce s_umount locking in writeback_inodes_sb
  writeback: queue work on stack in writeback_inodes_sb
  writeback: fix writeback completion notifications

block/blk-core.c

@@ -1149,13 +1149,10 @@ void init_request_from_bio(struct request *req, struct bio *bio)
 	else
 		req->cmd_flags |= bio->bi_rw & REQ_FAILFAST_MASK;
 
-	if (unlikely(bio_rw_flagged(bio, BIO_RW_DISCARD))) {
+	if (bio_rw_flagged(bio, BIO_RW_DISCARD))
 		req->cmd_flags |= REQ_DISCARD;
-		if (bio_rw_flagged(bio, BIO_RW_BARRIER))
-			req->cmd_flags |= REQ_SOFTBARRIER;
-	} else if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER)))
+	if (bio_rw_flagged(bio, BIO_RW_BARRIER))
 		req->cmd_flags |= REQ_HARDBARRIER;
-
 	if (bio_rw_flagged(bio, BIO_RW_SYNCIO))
 		req->cmd_flags |= REQ_RW_SYNC;
 	if (bio_rw_flagged(bio, BIO_RW_META))
@@ -1586,7 +1583,7 @@ void submit_bio(int rw, struct bio *bio)
 	 * If it's a regular read/write or a barrier with data attached,
 	 * go through the normal accounting stuff before submission.
 	 */
-	if (bio_has_data(bio)) {
+	if (bio_has_data(bio) && !(rw & (1 << BIO_RW_DISCARD))) {
 		if (rw & WRITE) {
 			count_vm_events(PGPGOUT, count);
 		} else {

block/cfq-iosched.c

@@ -14,7 +14,7 @@
 #include <linux/rbtree.h>
 #include <linux/ioprio.h>
 #include <linux/blktrace_api.h>
-#include "blk-cgroup.h"
+#include "cfq.h"
 
 /*
  * tunables
@@ -879,7 +879,7 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
 	if (!RB_EMPTY_NODE(&cfqg->rb_node))
 		cfq_rb_erase(&cfqg->rb_node, st);
 	cfqg->saved_workload_slice = 0;
-	blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
+	cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
 }
 
 static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq)
@@ -939,8 +939,8 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
 
 	cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
 					st->min_vdisktime);
-	blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
-	blkiocg_set_start_empty_time(&cfqg->blkg);
+	cfq_blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
+	cfq_blkiocg_set_start_empty_time(&cfqg->blkg);
 }
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
@@ -995,7 +995,7 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
 
 	/* Add group onto cgroup list */
 	sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
-	blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
+	cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
 					MKDEV(major, minor));
 	cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);
 
@@ -1079,7 +1079,7 @@ static void cfq_release_cfq_groups(struct cfq_data *cfqd)
 		 * it from cgroup list, then it will take care of destroying
 		 * cfqg also.
 		 */
-		if (!blkiocg_del_blkio_group(&cfqg->blkg))
+		if (!cfq_blkiocg_del_blkio_group(&cfqg->blkg))
 			cfq_destroy_cfqg(cfqd, cfqg);
 	}
 }
@@ -1421,10 +1421,10 @@ static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
 {
 	elv_rb_del(&cfqq->sort_list, rq);
 	cfqq->queued[rq_is_sync(rq)]--;
-	blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(rq),
-						rq_is_sync(rq));
+	cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,
+					rq_data_dir(rq), rq_is_sync(rq));
 	cfq_add_rq_rb(rq);
-	blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
+	cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
 			&cfqq->cfqd->serving_group->blkg, rq_data_dir(rq),
 			rq_is_sync(rq));
 }
@@ -1482,8 +1482,8 @@ static void cfq_remove_request(struct request *rq)
 	cfq_del_rq_rb(rq);
 
 	cfqq->cfqd->rq_queued--;
-	blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(rq),
-						rq_is_sync(rq));
+	cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,
+					rq_data_dir(rq), rq_is_sync(rq));
 	if (rq_is_meta(rq)) {
 		WARN_ON(!cfqq->meta_pending);
 		cfqq->meta_pending--;
@@ -1518,8 +1518,8 @@ static void cfq_merged_request(struct request_queue *q, struct request *req,
 static void cfq_bio_merged(struct request_queue *q, struct request *req,
 				struct bio *bio)
 {
-	blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg, bio_data_dir(bio),
-					cfq_bio_sync(bio));
+	cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg,
+					bio_data_dir(bio), cfq_bio_sync(bio));
 }
 
 static void
@@ -1539,8 +1539,8 @@ cfq_merged_requests(struct request_queue *q, struct request *rq,
 	if (cfqq->next_rq == next)
 		cfqq->next_rq = rq;
 	cfq_remove_request(next);
-	blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(next),
-					rq_is_sync(next));
+	cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg,
+					rq_data_dir(next), rq_is_sync(next));
 }
 
 static int cfq_allow_merge(struct request_queue *q, struct request *rq,
@@ -1571,7 +1571,7 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq,
 static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
 	del_timer(&cfqd->idle_slice_timer);
-	blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
+	cfq_blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
 }
 
 static void __cfq_set_active_queue(struct cfq_data *cfqd,
@@ -1580,7 +1580,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
 	if (cfqq) {
 		cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
 				cfqd->serving_prio, cfqd->serving_type);
-		blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
+		cfq_blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
 		cfqq->slice_start = 0;
 		cfqq->dispatch_start = jiffies;
 		cfqq->allocated_slice = 0;
@@ -1911,7 +1911,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
 	sl = cfqd->cfq_slice_idle;
 
 	mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
-	blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg);
+	cfq_blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg);
 	cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl);
 }
 
@@ -1931,7 +1931,7 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
 	elv_dispatch_sort(q, rq);
 
 	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
-	blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq),
+	cfq_blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq),
 					rq_data_dir(rq), rq_is_sync(rq));
 }
 
@@ -1986,6 +1986,15 @@ static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq)
 	int process_refs, new_process_refs;
 	struct cfq_queue *__cfqq;
 
+	/*
+	 * If there are no process references on the new_cfqq, then it is
+	 * unsafe to follow the ->new_cfqq chain as other cfqq's in the
+	 * chain may have dropped their last reference (not just their
+	 * last process reference).
+	 */
+	if (!cfqq_process_refs(new_cfqq))
+		return;
+
 	/* Avoid a circular list and skip interim queue merges */
 	while ((__cfqq = new_cfqq->new_cfqq)) {
 		if (__cfqq == cfqq)
@@ -1994,17 +2003,17 @@ static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq)
 	}
 
 	process_refs = cfqq_process_refs(cfqq);
+	new_process_refs = cfqq_process_refs(new_cfqq);
 	/*
 	 * If the process for the cfqq has gone away, there is no
 	 * sense in merging the queues.
 	 */
-	if (process_refs == 0)
+	if (process_refs == 0 || new_process_refs == 0)
 		return;
 
 	/*
 	 * Merge in the direction of the lesser amount of work.
 	 */
-	new_process_refs = cfqq_process_refs(new_cfqq);
 	if (new_process_refs >= process_refs) {
 		cfqq->new_cfqq = new_cfqq;
 		atomic_add(process_refs, &new_cfqq->ref);
@@ -3248,7 +3257,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 				cfq_clear_cfqq_wait_request(cfqq);
 				__blk_run_queue(cfqd->queue);
 			} else {
-				blkiocg_update_idle_time_stats(
+				cfq_blkiocg_update_idle_time_stats(
 						&cfqq->cfqg->blkg);
 				cfq_mark_cfqq_must_dispatch(cfqq);
 			}
@@ -3276,7 +3285,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
 	rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]);
 	list_add_tail(&rq->queuelist, &cfqq->fifo);
 	cfq_add_rq_rb(rq);
-	blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
+	cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg,
 			&cfqd->serving_group->blkg, rq_data_dir(rq),
 			rq_is_sync(rq));
 	cfq_rq_enqueued(cfqd, cfqq, rq);
@@ -3364,9 +3373,9 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
 	WARN_ON(!cfqq->dispatched);
 	cfqd->rq_in_driver--;
 	cfqq->dispatched--;
-	blkiocg_update_completion_stats(&cfqq->cfqg->blkg, rq_start_time_ns(rq),
-			rq_io_start_time_ns(rq), rq_data_dir(rq),
-			rq_is_sync(rq));
+	cfq_blkiocg_update_completion_stats(&cfqq->cfqg->blkg,
+			rq_start_time_ns(rq), rq_io_start_time_ns(rq),
+			rq_data_dir(rq), rq_is_sync(rq));
 
 	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 
@@ -3730,7 +3739,7 @@ static void cfq_exit_queue(struct elevator_queue *e)
 
 	cfq_put_async_queues(cfqd);
 	cfq_release_cfq_groups(cfqd);
-	blkiocg_del_blkio_group(&cfqd->root_group.blkg);
+	cfq_blkiocg_del_blkio_group(&cfqd->root_group.blkg);
 
 	spin_unlock_irq(q->queue_lock);
 
@@ -3798,8 +3807,8 @@ static void *cfq_init_queue(struct request_queue *q)
 	 */
 	atomic_set(&cfqg->ref, 1);
 	rcu_read_lock();
-	blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd,
-					0);
+	cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg,
+					(void *)cfqd, 0);
 	rcu_read_unlock();
 #endif
 	/*

block/cfq.h

+#ifndef _CFQ_H
+#define _CFQ_H
+#include "blk-cgroup.h"
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+static inline void cfq_blkiocg_update_io_add_stats(struct blkio_group *blkg,
+	struct blkio_group *curr_blkg, bool direction, bool sync)
+{
+	blkiocg_update_io_add_stats(blkg, curr_blkg, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_dequeue_stats(struct blkio_group *blkg,
+			unsigned long dequeue)
+{
+	blkiocg_update_dequeue_stats(blkg, dequeue);
+}
+
+static inline void cfq_blkiocg_update_timeslice_used(struct blkio_group *blkg,
+			unsigned long time)
+{
+	blkiocg_update_timeslice_used(blkg, time);
+}
+
+static inline void cfq_blkiocg_set_start_empty_time(struct blkio_group *blkg)
+{
+	blkiocg_set_start_empty_time(blkg);
+}
+
+static inline void cfq_blkiocg_update_io_remove_stats(struct blkio_group *blkg,
+				bool direction, bool sync)
+{
+	blkiocg_update_io_remove_stats(blkg, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_io_merged_stats(struct blkio_group *blkg,
+		bool direction, bool sync)
+{
+	blkiocg_update_io_merged_stats(blkg, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_idle_time_stats(struct blkio_group *blkg)
+{
+	blkiocg_update_idle_time_stats(blkg);
+}
+
+static inline void
+cfq_blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg)
+{
+	blkiocg_update_avg_queue_size_stats(blkg);
+}
+
+static inline void
+cfq_blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
+{
+	blkiocg_update_set_idle_time_stats(blkg);
+}
+
+static inline void cfq_blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+				uint64_t bytes, bool direction, bool sync)
+{
+	blkiocg_update_dispatch_stats(blkg, bytes, direction, sync);
+}
+
+static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg, uint64_t start_time, uint64_t io_start_time, bool direction, bool sync)
+{
+	blkiocg_update_completion_stats(blkg, start_time, io_start_time,
+				direction, sync);
+}
+
+static inline void cfq_blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
+			struct blkio_group *blkg, void *key, dev_t dev) {
+	blkiocg_add_blkio_group(blkcg, blkg, key, dev);
+}
+
+static inline int cfq_blkiocg_del_blkio_group(struct blkio_group *blkg)
+{
+	return blkiocg_del_blkio_group(blkg);
+}
+
+#else /* CFQ_GROUP_IOSCHED */
+static inline void cfq_blkiocg_update_io_add_stats(struct blkio_group *blkg,
+	struct blkio_group *curr_blkg, bool direction, bool sync) {}
+
+static inline void cfq_blkiocg_update_dequeue_stats(struct blkio_group *blkg,
+			unsigned long dequeue) {}
+
+static inline void cfq_blkiocg_update_timeslice_used(struct blkio_group *blkg,
+			unsigned long time) {}
+static inline void cfq_blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
+static inline void cfq_blkiocg_update_io_remove_stats(struct blkio_group *blkg,
+				bool direction, bool sync) {}
+static inline void cfq_blkiocg_update_io_merged_stats(struct blkio_group *blkg,
+		bool direction, bool sync) {}
+static inline void cfq_blkiocg_update_idle_time_stats(struct blkio_group *blkg)
+{
+}
+static inline void
+cfq_blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg) {}
+
+static inline void
+cfq_blkiocg_update_set_idle_time_stats(struct blkio_group *blkg) {}
+
+static inline void cfq_blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+				uint64_t bytes, bool direction, bool sync) {}
+static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg, uint64_t start_time, uint64_t io_start_time, bool direction, bool sync) {}
+
+static inline void cfq_blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
+			struct blkio_group *blkg, void *key, dev_t dev) {}
+static inline int cfq_blkiocg_del_blkio_group(struct blkio_group *blkg)
+{
+	return 0;
+}
+
+#endif /* CFQ_GROUP_IOSCHED */
+#endif

drivers/block/cciss_scsi.c

@@ -861,6 +861,7 @@ cciss_scsi_detect(int ctlr)
 	sh->n_io_port = 0;	// I don't think we use these two...
 	sh->this_id = SELF_SCSI_ID;  
 	sh->sg_tablesize = hba[ctlr]->maxsgentries;
+	sh->max_cmd_len = MAX_COMMAND_SIZE;
 
 	((struct cciss_scsi_adapter_data_t *) 
 		hba[ctlr]->scsi_ctlr)->scsi_host = sh;

drivers/block/cpqarray.c

@@ -386,7 +386,7 @@ static void __devexit cpqarray_remove_one_eisa (int i)
 }
 
 /* pdev is NULL for eisa */
-static int __init cpqarray_register_ctlr( int i, struct pci_dev *pdev)
+static int __devinit cpqarray_register_ctlr( int i, struct pci_dev *pdev)
 {
 	struct request_queue *q;
 	int j;
@@ -503,7 +503,7 @@ static int __init cpqarray_register_ctlr( int i, struct pci_dev *pdev)
 	return -1;
 }
 
-static int __init cpqarray_init_one( struct pci_dev *pdev,
+static int __devinit cpqarray_init_one( struct pci_dev *pdev,
 	const struct pci_device_id *ent)
 {
 	int i;
@@ -740,7 +740,7 @@ __setup("smart2=", cpqarray_setup);
 /*
  * Find an EISA controller's signature.  Set up an hba if we find it.
  */
-static int __init cpqarray_eisa_detect(void)
+static int __devinit cpqarray_eisa_detect(void)
 {
 	int i=0, j;
 	__u32 board_id;

drivers/block/drbd/drbd_main.c

@@ -1236,8 +1236,6 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
 	/* Last part of the attaching process ... */
 	if (ns.conn >= C_CONNECTED &&
 	    os.disk == D_ATTACHING && ns.disk == D_NEGOTIATING) {
-		kfree(mdev->p_uuid); /* We expect to receive up-to-date UUIDs soon. */
-		mdev->p_uuid = NULL; /* ...to not use the old ones in the mean time */
 		drbd_send_sizes(mdev, 0, 0);  /* to start sync... */
 		drbd_send_uuids(mdev);
 		drbd_send_state(mdev);

drivers/block/drbd/drbd_nl.c

@@ -1114,6 +1114,12 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
 		mdev->new_state_tmp.i = ns.i;
 		ns.i = os.i;
 		ns.disk = D_NEGOTIATING;
+
+		/* We expect to receive up-to-date UUIDs soon.
+		   To avoid a race in receive_state, free p_uuid while
+		   holding req_lock. I.e. atomic with the state change */
+		kfree(mdev->p_uuid);
+		mdev->p_uuid = NULL;
 	}
 
 	rv = _drbd_set_state(mdev, ns, CS_VERBOSE, NULL);

fs/ubifs/budget.c

@@ -62,7 +62,9 @@
  */
 static void shrink_liability(struct ubifs_info *c, int nr_to_write)
 {
+	down_read(&c->vfs_sb->s_umount);
 	writeback_inodes_sb(c->vfs_sb);
+	up_read(&c->vfs_sb->s_umount);
 }
 
 /**

include/linux/backing-dev.h

@@ -105,8 +105,8 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
 int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
 void bdi_unregister(struct backing_dev_info *bdi);
 int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int);
-void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
-				long nr_pages);
+void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages);
+void bdi_start_background_writeback(struct backing_dev_info *bdi);
 int bdi_writeback_task(struct bdi_writeback *wb);
 int bdi_has_dirty_io(struct backing_dev_info *bdi);
 void bdi_arm_supers_timer(void);

include/linux/drbd.h

@@ -53,7 +53,7 @@
 
 
 extern const char *drbd_buildtag(void);
-#define REL_VERSION "8.3.8rc2"
+#define REL_VERSION "8.3.8"
 #define API_VERSION 88
 #define PRO_VERSION_MIN 86
 #define PRO_VERSION_MAX 94

mm/page-writeback.c

@@ -597,7 +597,7 @@ static void balance_dirty_pages(struct address_space *mapping,
 	    (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
 			       + global_page_state(NR_UNSTABLE_NFS))
 					  > background_thresh)))
-		bdi_start_writeback(bdi, NULL, 0);
+		bdi_start_background_writeback(bdi);
 }
 
 void set_page_dirty_balance(struct page *page, int page_mkwrite)
@@ -705,9 +705,8 @@ void laptop_mode_timer_fn(unsigned long data)
 	 * We want to write everything out, not just down to the dirty
 	 * threshold
 	 */
-
 	if (bdi_has_dirty_io(&q->backing_dev_info))
-		bdi_start_writeback(&q->backing_dev_info, NULL, nr_pages);
+		bdi_start_writeback(&q->backing_dev_info, nr_pages);
 }
 
 /*