Merge branch 'for-linus' into for-2.6.40/core

This patch merges in a fix that missed 2.6.39 final.

Conflicts:
	block/blk.h
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index 4873c75..c1eb41c 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -142,3 +142,67 @@
 		with the previous I/O request are enabled. When set to 2,
 		all merge tries are disabled. The default value is 0 -
 		which enables all types of merge tries.
+
+What:		/sys/block/<disk>/discard_alignment
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may
+		internally allocate space in units that are bigger than
+		the exported logical block size. The discard_alignment
+		parameter indicates how many bytes the beginning of the
+		device is offset from the internal allocation unit's
+		natural alignment.
+
+What:		/sys/block/<disk>/<partition>/discard_alignment
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may
+		internally allocate space in units that are bigger than
+		the exported logical block size. The discard_alignment
+		parameter indicates how many bytes the beginning of the
+		partition is offset from the internal allocation unit's
+		natural alignment.
+
+What:		/sys/block/<disk>/queue/discard_granularity
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may
+		internally allocate space using units that are bigger
+		than the logical block size. The discard_granularity
+		parameter indicates the size of the internal allocation
+		unit in bytes if reported by the device. Otherwise the
+		discard_granularity will be set to match the device's
+		physical block size. A discard_granularity of 0 means
+		that the device does not support discard functionality.
+
+What:		/sys/block/<disk>/queue/discard_max_bytes
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may have
+		internal limits on the number of bytes that can be
+		trimmed or unmapped in a single operation. Some storage
+		protocols also have inherent limits on the number of
+		blocks that can be described in a single command. The
+		discard_max_bytes parameter is set by the device driver
+		to the maximum number of bytes that can be discarded in
+		a single operation. Discard requests issued to the
+		device must not exceed this limit. A discard_max_bytes
+		value of 0 means that the device does not support
+		discard functionality.
+
+What:		/sys/block/<disk>/queue/discard_zeroes_data
+Date:		May 2011
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Devices that support discard functionality may return
+		stale or random data when a previously discarded block
+		is read back. This can cause problems if the filesystem
+		expects discarded blocks to be explicitly cleared. If a
+		device reports that it deterministically returns zeroes
+		when a discarded area is read the discard_zeroes_data
+		parameter will be set to one. Otherwise it will be 0 and
+		the result of reading a discarded area is undefined.
diff --git a/Makefile b/Makefile
index 41ea6fb..123d858d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 2
 PATCHLEVEL = 6
 SUBLEVEL = 39
-EXTRAVERSION = -rc7
+EXTRAVERSION =
 NAME = Flesh-Eating Bats with Fangs
 
 # *DOCUMENTATION*
diff --git a/arch/mips/ar7/gpio.c b/arch/mips/ar7/gpio.c
index 425dfa5..bb571bc 100644
--- a/arch/mips/ar7/gpio.c
+++ b/arch/mips/ar7/gpio.c
@@ -325,9 +325,7 @@
 		size = 0x1f;
 	}
 
-	gpch->regs = ioremap_nocache(AR7_REGS_GPIO,
-					AR7_REGS_GPIO + 0x10);
-
+	gpch->regs = ioremap_nocache(AR7_REGS_GPIO, size);
 	if (!gpch->regs) {
 		printk(KERN_ERR "%s: failed to ioremap regs\n",
 					gpch->chip.label);
diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
index 655f849..7aa37dd 100644
--- a/arch/mips/include/asm/dma-mapping.h
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -5,7 +5,9 @@
 #include <asm/cache.h>
 #include <asm-generic/dma-coherent.h>
 
+#ifndef CONFIG_SGI_IP27	/* Kludge to fix 2.6.39 build for IP27 */
 #include <dma-coherence.h>
+#endif
 
 extern struct dma_map_ops *mips_dma_map_ops;
 
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 71350f7..e9b3af2 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -374,7 +374,8 @@
 	unsigned long dvpret = dvpe();
 #endif /* CONFIG_MIPS_MT_SMTC */
 
-	notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV);
+	if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP)
+		sig = 0;
 
 	console_verbose();
 	spin_lock_irq(&die_lock);
@@ -383,9 +384,6 @@
 	mips_mt_regdump(dvpret);
 #endif /* CONFIG_MIPS_MT_SMTC */
 
-	if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP)
-		sig = 0;
-
 	printk("%s[#%d]:\n", str, ++die_counter);
 	show_registers(regs);
 	add_taint(TAINT_DIE);
diff --git a/arch/mips/rb532/gpio.c b/arch/mips/rb532/gpio.c
index 37de05d..6c47dfe 100644
--- a/arch/mips/rb532/gpio.c
+++ b/arch/mips/rb532/gpio.c
@@ -185,7 +185,7 @@
 	struct resource *r;
 
 	r = rb532_gpio_reg0_res;
-	rb532_gpio_chip->regbase = ioremap_nocache(r->start, r->end - r->start);
+	rb532_gpio_chip->regbase = ioremap_nocache(r->start, resource_size(r));
 
 	if (!rb532_gpio_chip->regbase) {
 		printk(KERN_ERR "rb532: cannot remap GPIO register 0\n");
diff --git a/arch/powerpc/platforms/83xx/suspend.c b/arch/powerpc/platforms/83xx/suspend.c
index 1882729..104faa8 100644
--- a/arch/powerpc/platforms/83xx/suspend.c
+++ b/arch/powerpc/platforms/83xx/suspend.c
@@ -318,17 +318,20 @@
 	.end = mpc83xx_suspend_end,
 };
 
+static struct of_device_id pmc_match[];
 static int pmc_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct resource res;
 	struct pmc_type *type;
 	int ret = 0;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(pmc_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
-	type = ofdev->dev.of_match->data;
+	type = match->data;
 
 	if (!of_device_is_available(np))
 		return -ENODEV;
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index d5679dc..01cd2f0 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -304,8 +304,10 @@
 	return 0;
 }
 
+static const struct of_device_id fsl_of_msi_ids[];
 static int __devinit fsl_of_msi_probe(struct platform_device *dev)
 {
+	const struct of_device_id *match;
 	struct fsl_msi *msi;
 	struct resource res;
 	int err, i, j, irq_index, count;
@@ -316,9 +318,10 @@
 	u32 offset;
 	static const u32 all_avail[] = { 0, NR_MSI_IRQS };
 
-	if (!dev->dev.of_match)
+	match = of_match_device(fsl_of_msi_ids, &dev->dev);
+	if (!match)
 		return -EINVAL;
-	features = dev->dev.of_match->data;
+	features = match->data;
 
 	printk(KERN_DEBUG "Setting up Freescale MSI support\n");
 
diff --git a/arch/sparc/kernel/pci_sabre.c b/arch/sparc/kernel/pci_sabre.c
index 948068a..d1840db 100644
--- a/arch/sparc/kernel/pci_sabre.c
+++ b/arch/sparc/kernel/pci_sabre.c
@@ -452,8 +452,10 @@
 	sabre_scan_bus(pbm, &op->dev);
 }
 
+static const struct of_device_id sabre_match[];
 static int __devinit sabre_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	const struct linux_prom64_registers *pr_regs;
 	struct device_node *dp = op->dev.of_node;
 	struct pci_pbm_info *pbm;
@@ -463,7 +465,8 @@
 	const u32 *vdma;
 	u64 clear_irq;
 
-	hummingbird_p = op->dev.of_match && (op->dev.of_match->data != NULL);
+	match = of_match_device(sabre_match, &op->dev);
+	hummingbird_p = match && (match->data != NULL);
 	if (!hummingbird_p) {
 		struct device_node *cpu_dp;
 
diff --git a/arch/sparc/kernel/pci_schizo.c b/arch/sparc/kernel/pci_schizo.c
index fecfcb2..283fbc3 100644
--- a/arch/sparc/kernel/pci_schizo.c
+++ b/arch/sparc/kernel/pci_schizo.c
@@ -1458,11 +1458,15 @@
 	return err;
 }
 
+static const struct of_device_id schizo_match[];
 static int __devinit schizo_probe(struct platform_device *op)
 {
-	if (!op->dev.of_match)
+	const struct of_device_id *match;
+
+	match = of_match_device(schizo_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	return __schizo_init(op, (unsigned long) op->dev.of_match->data);
+	return __schizo_init(op, (unsigned long)match->data);
 }
 
 /* The ordering of this table is very important.  Some Tomatillo
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 471fdcc..e41cc6f 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -385,25 +385,40 @@
 
 	spin_lock_irqsave(&blkg->stats_lock, flags);
 	blkg->stats.time += time;
+#ifdef CONFIG_DEBUG_BLK_CGROUP
 	blkg->stats.unaccounted_time += unaccounted_time;
+#endif
 	spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
 
+/*
+ * should be called under rcu read lock or queue lock to make sure blkg pointer
+ * is valid.
+ */
 void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
 				uint64_t bytes, bool direction, bool sync)
 {
-	struct blkio_group_stats *stats;
+	struct blkio_group_stats_cpu *stats_cpu;
 	unsigned long flags;
 
-	spin_lock_irqsave(&blkg->stats_lock, flags);
-	stats = &blkg->stats;
-	stats->sectors += bytes >> 9;
-	blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction,
-			sync);
-	blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes,
-			direction, sync);
-	spin_unlock_irqrestore(&blkg->stats_lock, flags);
+	/*
+	 * Disabling interrupts to provide mutual exclusion between two
+	 * writes on same cpu. It probably is not needed for 64bit. Not
+	 * optimizing that case yet.
+	 */
+	local_irq_save(flags);
+
+	stats_cpu = this_cpu_ptr(blkg->stats_cpu);
+
+	u64_stats_update_begin(&stats_cpu->syncp);
+	stats_cpu->sectors += bytes >> 9;
+	blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICED],
+			1, direction, sync);
+	blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICE_BYTES],
+			bytes, direction, sync);
+	u64_stats_update_end(&stats_cpu->syncp);
+	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats);
 
@@ -438,6 +453,20 @@
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
 
+/*
+ * This function allocates the per cpu stats for blkio_group. Should be called
+ * from sleepable context as alloc_per_cpu() requires that.
+ */
+int blkio_alloc_blkg_stats(struct blkio_group *blkg)
+{
+	/* Allocate memory for per cpu stats */
+	blkg->stats_cpu = alloc_percpu(struct blkio_group_stats_cpu);
+	if (!blkg->stats_cpu)
+		return -ENOMEM;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blkio_alloc_blkg_stats);
+
 void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 		struct blkio_group *blkg, void *key, dev_t dev,
 		enum blkio_policy_id plid)
@@ -508,6 +537,30 @@
 }
 EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
 
+static void blkio_reset_stats_cpu(struct blkio_group *blkg)
+{
+	struct blkio_group_stats_cpu *stats_cpu;
+	int i, j, k;
+	/*
+	 * Note: On 64 bit arch this should not be an issue. This has the
+	 * possibility of returning some inconsistent value on 32bit arch
+	 * as 64bit update on 32bit is non atomic. Taking care of this
+	 * corner case makes code very complicated, like sending IPIs to
+	 * cpus, taking care of stats of offline cpus etc.
+	 *
+	 * reset stats is anyway more of a debug feature and this sounds a
+	 * corner case. So I am not complicating the code yet until and
+	 * unless this becomes a real issue.
+	 */
+	for_each_possible_cpu(i) {
+		stats_cpu = per_cpu_ptr(blkg->stats_cpu, i);
+		stats_cpu->sectors = 0;
+		for(j = 0; j < BLKIO_STAT_CPU_NR; j++)
+			for (k = 0; k < BLKIO_STAT_TOTAL; k++)
+				stats_cpu->stat_arr_cpu[j][k] = 0;
+	}
+}
+
 static int
 blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
 {
@@ -552,7 +605,11 @@
 		}
 #endif
 		spin_unlock(&blkg->stats_lock);
+
+		/* Reset Per cpu stats which don't take blkg->stats_lock */
+		blkio_reset_stats_cpu(blkg);
 	}
+
 	spin_unlock_irq(&blkcg->lock);
 	return 0;
 }
@@ -598,6 +655,59 @@
 	return val;
 }
 
+
+static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg,
+			enum stat_type_cpu type, enum stat_sub_type sub_type)
+{
+	int cpu;
+	struct blkio_group_stats_cpu *stats_cpu;
+	u64 val = 0, tval;
+
+	for_each_possible_cpu(cpu) {
+		unsigned int start;
+		stats_cpu  = per_cpu_ptr(blkg->stats_cpu, cpu);
+
+		do {
+			start = u64_stats_fetch_begin(&stats_cpu->syncp);
+			if (type == BLKIO_STAT_CPU_SECTORS)
+				tval = stats_cpu->sectors;
+			else
+				tval = stats_cpu->stat_arr_cpu[type][sub_type];
+		} while(u64_stats_fetch_retry(&stats_cpu->syncp, start));
+
+		val += tval;
+	}
+
+	return val;
+}
+
+static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg,
+		struct cgroup_map_cb *cb, dev_t dev, enum stat_type_cpu type)
+{
+	uint64_t disk_total, val;
+	char key_str[MAX_KEY_LEN];
+	enum stat_sub_type sub_type;
+
+	if (type == BLKIO_STAT_CPU_SECTORS) {
+		val = blkio_read_stat_cpu(blkg, type, 0);
+		return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, val, cb, dev);
+	}
+
+	for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL;
+			sub_type++) {
+		blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false);
+		val = blkio_read_stat_cpu(blkg, type, sub_type);
+		cb->fill(cb, key_str, val);
+	}
+
+	disk_total = blkio_read_stat_cpu(blkg, type, BLKIO_STAT_READ) +
+			blkio_read_stat_cpu(blkg, type, BLKIO_STAT_WRITE);
+
+	blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false);
+	cb->fill(cb, key_str, disk_total);
+	return disk_total;
+}
+
 /* This should be called with blkg->stats_lock held */
 static uint64_t blkio_get_stat(struct blkio_group *blkg,
 		struct cgroup_map_cb *cb, dev_t dev, enum stat_type type)
@@ -609,9 +719,6 @@
 	if (type == BLKIO_STAT_TIME)
 		return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
 					blkg->stats.time, cb, dev);
-	if (type == BLKIO_STAT_SECTORS)
-		return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
-					blkg->stats.sectors, cb, dev);
 #ifdef CONFIG_DEBUG_BLK_CGROUP
 	if (type == BLKIO_STAT_UNACCOUNTED_TIME)
 		return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
@@ -1075,8 +1182,8 @@
 }
 
 static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg,
-		struct cftype *cft, struct cgroup_map_cb *cb, enum stat_type type,
-		bool show_total)
+		struct cftype *cft, struct cgroup_map_cb *cb,
+		enum stat_type type, bool show_total, bool pcpu)
 {
 	struct blkio_group *blkg;
 	struct hlist_node *n;
@@ -1087,10 +1194,15 @@
 		if (blkg->dev) {
 			if (!cftype_blkg_same_policy(cft, blkg))
 				continue;
-			spin_lock_irq(&blkg->stats_lock);
-			cgroup_total += blkio_get_stat(blkg, cb, blkg->dev,
-						type);
-			spin_unlock_irq(&blkg->stats_lock);
+			if (pcpu)
+				cgroup_total += blkio_get_stat_cpu(blkg, cb,
+						blkg->dev, type);
+			else {
+				spin_lock_irq(&blkg->stats_lock);
+				cgroup_total += blkio_get_stat(blkg, cb,
+						blkg->dev, type);
+				spin_unlock_irq(&blkg->stats_lock);
+			}
 		}
 	}
 	if (show_total)
@@ -1114,47 +1226,47 @@
 		switch(name) {
 		case BLKIO_PROP_time:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_TIME, 0);
+						BLKIO_STAT_TIME, 0, 0);
 		case BLKIO_PROP_sectors:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_SECTORS, 0);
+						BLKIO_STAT_CPU_SECTORS, 0, 1);
 		case BLKIO_PROP_io_service_bytes:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_SERVICE_BYTES, 1);
+					BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1);
 		case BLKIO_PROP_io_serviced:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_SERVICED, 1);
+						BLKIO_STAT_CPU_SERVICED, 1, 1);
 		case BLKIO_PROP_io_service_time:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_SERVICE_TIME, 1);
+						BLKIO_STAT_SERVICE_TIME, 1, 0);
 		case BLKIO_PROP_io_wait_time:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_WAIT_TIME, 1);
+						BLKIO_STAT_WAIT_TIME, 1, 0);
 		case BLKIO_PROP_io_merged:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_MERGED, 1);
+						BLKIO_STAT_MERGED, 1, 0);
 		case BLKIO_PROP_io_queued:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_QUEUED, 1);
+						BLKIO_STAT_QUEUED, 1, 0);
 #ifdef CONFIG_DEBUG_BLK_CGROUP
 		case BLKIO_PROP_unaccounted_time:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_UNACCOUNTED_TIME, 0);
+					BLKIO_STAT_UNACCOUNTED_TIME, 0, 0);
 		case BLKIO_PROP_dequeue:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_DEQUEUE, 0);
+						BLKIO_STAT_DEQUEUE, 0, 0);
 		case BLKIO_PROP_avg_queue_size:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_AVG_QUEUE_SIZE, 0);
+					BLKIO_STAT_AVG_QUEUE_SIZE, 0, 0);
 		case BLKIO_PROP_group_wait_time:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_GROUP_WAIT_TIME, 0);
+					BLKIO_STAT_GROUP_WAIT_TIME, 0, 0);
 		case BLKIO_PROP_idle_time:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_IDLE_TIME, 0);
+						BLKIO_STAT_IDLE_TIME, 0, 0);
 		case BLKIO_PROP_empty_time:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_EMPTY_TIME, 0);
+						BLKIO_STAT_EMPTY_TIME, 0, 0);
 #endif
 		default:
 			BUG();
@@ -1164,10 +1276,10 @@
 		switch(name){
 		case BLKIO_THROTL_io_service_bytes:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_SERVICE_BYTES, 1);
+						BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1);
 		case BLKIO_THROTL_io_serviced:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
-						BLKIO_STAT_SERVICED, 1);
+						BLKIO_STAT_CPU_SERVICED, 1, 1);
 		default:
 			BUG();
 		}
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index c774930..2622267 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -14,6 +14,7 @@
  */
 
 #include <linux/cgroup.h>
+#include <linux/u64_stats_sync.h>
 
 enum blkio_policy_id {
 	BLKIO_POLICY_PROP = 0,		/* Proportional Bandwidth division */
@@ -36,10 +37,6 @@
 	 * request completion for IOs doen by this cgroup. This may not be
 	 * accurate when NCQ is turned on. */
 	BLKIO_STAT_SERVICE_TIME = 0,
-	/* Total bytes transferred */
-	BLKIO_STAT_SERVICE_BYTES,
-	/* Total IOs serviced, post merge */
-	BLKIO_STAT_SERVICED,
 	/* Total time spent waiting in scheduler queue in ns */
 	BLKIO_STAT_WAIT_TIME,
 	/* Number of IOs merged */
@@ -48,10 +45,9 @@
 	BLKIO_STAT_QUEUED,
 	/* All the single valued stats go below this */
 	BLKIO_STAT_TIME,
-	BLKIO_STAT_SECTORS,
+#ifdef CONFIG_DEBUG_BLK_CGROUP
 	/* Time not charged to this cgroup */
 	BLKIO_STAT_UNACCOUNTED_TIME,
-#ifdef CONFIG_DEBUG_BLK_CGROUP
 	BLKIO_STAT_AVG_QUEUE_SIZE,
 	BLKIO_STAT_IDLE_TIME,
 	BLKIO_STAT_EMPTY_TIME,
@@ -60,6 +56,16 @@
 #endif
 };
 
+/* Per cpu stats */
+enum stat_type_cpu {
+	BLKIO_STAT_CPU_SECTORS,
+	/* Total bytes transferred */
+	BLKIO_STAT_CPU_SERVICE_BYTES,
+	/* Total IOs serviced, post merge */
+	BLKIO_STAT_CPU_SERVICED,
+	BLKIO_STAT_CPU_NR
+};
+
 enum stat_sub_type {
 	BLKIO_STAT_READ = 0,
 	BLKIO_STAT_WRITE,
@@ -116,11 +122,11 @@
 struct blkio_group_stats {
 	/* total disk time and nr sectors dispatched by this group */
 	uint64_t time;
-	uint64_t sectors;
-	/* Time not charged to this cgroup */
-	uint64_t unaccounted_time;
 	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
 #ifdef CONFIG_DEBUG_BLK_CGROUP
+	/* Time not charged to this cgroup */
+	uint64_t unaccounted_time;
+
 	/* Sum of number of IOs queued across all samples */
 	uint64_t avg_queue_size_sum;
 	/* Count of samples taken for average */
@@ -145,6 +151,13 @@
 #endif
 };
 
+/* Per cpu blkio group stats */
+struct blkio_group_stats_cpu {
+	uint64_t sectors;
+	uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
+	struct u64_stats_sync syncp;
+};
+
 struct blkio_group {
 	/* An rcu protected unique identifier for the group */
 	void *key;
@@ -160,6 +173,8 @@
 	/* Need to serialize the stats in the case of reset/update */
 	spinlock_t stats_lock;
 	struct blkio_group_stats stats;
+	/* Per cpu stats pointer */
+	struct blkio_group_stats_cpu __percpu *stats_cpu;
 };
 
 struct blkio_policy_node {
@@ -295,6 +310,7 @@
 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 	struct blkio_group *blkg, void *key, dev_t dev,
 	enum blkio_policy_id plid);
+extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
 						void *key);
@@ -322,6 +338,8 @@
 		struct blkio_group *blkg, void *key, dev_t dev,
 		enum blkio_policy_id plid) {}
 
+static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }
+
 static inline int
 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
 
diff --git a/block/blk-core.c b/block/blk-core.c
index 3fe00a1..9e8e297 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1550,7 +1550,8 @@
 			goto end_io;
 		}
 
-		blk_throtl_bio(q, &bio);
+		if (blk_throtl_bio(q, &bio))
+			goto end_io;
 
 		/*
 		 * If bio = NULL, bio has been throttled and will be submitted
diff --git a/block/blk-exec.c b/block/blk-exec.c
index 81e3181..8a0e7ec 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -56,7 +56,7 @@
 	spin_lock_irq(q->queue_lock);
 	__elv_add_request(q, rq, where);
 	__blk_run_queue(q);
-	/* the queue is stopped so it won't be plugged+unplugged */
+	/* the queue is stopped so it won't be run */
 	if (rq->cmd_type == REQ_TYPE_PM_RESUME)
 		q->request_fn(q);
 	spin_unlock_irq(q->queue_lock);
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 6c9b5e1..bb21e4c 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -212,13 +212,19 @@
 	}
 
 	/*
-	 * Moving a request silently to empty queue_head may stall the
-	 * queue.  Kick the queue in those cases.  This function is called
-	 * from request completion path and calling directly into
-	 * request_fn may confuse the driver.  Always use kblockd.
+	 * Kick the queue to avoid stall for two cases:
+	 * 1. Moving a request silently to empty queue_head may stall the
+	 * queue.
+	 * 2. When flush request is running in non-queueable queue, the
+	 * queue is hold. Restart the queue after flush request is finished
+	 * to avoid stall.
+	 * This function is called from request completion path and calling
+	 * directly into request_fn may confuse the driver.  Always use
+	 * kblockd.
 	 */
-	if (queued)
+	if (queued || q->flush_queue_delayed)
 		blk_run_queue_async(q);
+	q->flush_queue_delayed = 0;
 }
 
 /**
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 25de73e..78e627e 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -9,17 +9,20 @@
 
 #include "blk.h"
 
-static void blkdev_discard_end_io(struct bio *bio, int err)
+struct bio_batch {
+	atomic_t		done;
+	unsigned long		flags;
+	struct completion	*wait;
+};
+
+static void bio_batch_end_io(struct bio *bio, int err)
 {
-	if (err) {
-		if (err == -EOPNOTSUPP)
-			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
-		clear_bit(BIO_UPTODATE, &bio->bi_flags);
-	}
+	struct bio_batch *bb = bio->bi_private;
 
-	if (bio->bi_private)
-		complete(bio->bi_private);
-
+	if (err && (err != -EOPNOTSUPP))
+		clear_bit(BIO_UPTODATE, &bb->flags);
+	if (atomic_dec_and_test(&bb->done))
+		complete(bb->wait);
 	bio_put(bio);
 }
 
@@ -41,6 +44,7 @@
 	struct request_queue *q = bdev_get_queue(bdev);
 	int type = REQ_WRITE | REQ_DISCARD;
 	unsigned int max_discard_sectors;
+	struct bio_batch bb;
 	struct bio *bio;
 	int ret = 0;
 
@@ -67,7 +71,11 @@
 		type |= REQ_SECURE;
 	}
 
-	while (nr_sects && !ret) {
+	atomic_set(&bb.done, 1);
+	bb.flags = 1 << BIO_UPTODATE;
+	bb.wait = &wait;
+
+	while (nr_sects) {
 		bio = bio_alloc(gfp_mask, 1);
 		if (!bio) {
 			ret = -ENOMEM;
@@ -75,9 +83,9 @@
 		}
 
 		bio->bi_sector = sector;
-		bio->bi_end_io = blkdev_discard_end_io;
+		bio->bi_end_io = bio_batch_end_io;
 		bio->bi_bdev = bdev;
-		bio->bi_private = &wait;
+		bio->bi_private = &bb;
 
 		if (nr_sects > max_discard_sectors) {
 			bio->bi_size = max_discard_sectors << 9;
@@ -88,45 +96,21 @@
 			nr_sects = 0;
 		}
 
-		bio_get(bio);
+		atomic_inc(&bb.done);
 		submit_bio(type, bio);
+	}
 
+	/* Wait for bios in-flight */
+	if (!atomic_dec_and_test(&bb.done))
 		wait_for_completion(&wait);
 
-		if (bio_flagged(bio, BIO_EOPNOTSUPP))
-			ret = -EOPNOTSUPP;
-		else if (!bio_flagged(bio, BIO_UPTODATE))
-			ret = -EIO;
-		bio_put(bio);
-	}
+	if (!test_bit(BIO_UPTODATE, &bb.flags))
+		ret = -EIO;
 
 	return ret;
 }
 EXPORT_SYMBOL(blkdev_issue_discard);
 
-struct bio_batch
-{
-	atomic_t 		done;
-	unsigned long 		flags;
-	struct completion 	*wait;
-};
-
-static void bio_batch_end_io(struct bio *bio, int err)
-{
-	struct bio_batch *bb = bio->bi_private;
-
-	if (err) {
-		if (err == -EOPNOTSUPP)
-			set_bit(BIO_EOPNOTSUPP, &bb->flags);
-		else
-			clear_bit(BIO_UPTODATE, &bb->flags);
-	}
-	if (bb)
-		if (atomic_dec_and_test(&bb->done))
-			complete(bb->wait);
-	bio_put(bio);
-}
-
 /**
  * blkdev_issue_zeroout - generate number of zero filed write bios
  * @bdev:	blockdev to issue
@@ -151,7 +135,6 @@
 	bb.flags = 1 << BIO_UPTODATE;
 	bb.wait = &wait;
 
-submit:
 	ret = 0;
 	while (nr_sects != 0) {
 		bio = bio_alloc(gfp_mask,
@@ -168,9 +151,6 @@
 
 		while (nr_sects != 0) {
 			sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
-			if (sz == 0)
-				/* bio has maximum size possible */
-				break;
 			ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
 			nr_sects -= ret >> 9;
 			sector += ret >> 9;
@@ -190,16 +170,6 @@
 		/* One of bios in the batch was completed with error.*/
 		ret = -EIO;
 
-	if (ret)
-		goto out;
-
-	if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
-	if (nr_sects != 0)
-		goto submit;
-out:
 	return ret;
 }
 EXPORT_SYMBOL(blkdev_issue_zeroout);
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 1fa7692..fa1eb04 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -120,7 +120,7 @@
 	lim->discard_granularity = 0;
 	lim->discard_alignment = 0;
 	lim->discard_misaligned = 0;
-	lim->discard_zeroes_data = -1;
+	lim->discard_zeroes_data = 1;
 	lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
 	lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
 	lim->alignment_offset = 0;
@@ -166,6 +166,7 @@
 
 	blk_set_default_limits(&q->limits);
 	blk_queue_max_hw_sectors(q, BLK_SAFE_MAX_SECTORS);
+	q->limits.discard_zeroes_data = 0;
 
 	/*
 	 * by default assume old behaviour and bounce for any highmem page
@@ -790,6 +791,12 @@
 }
 EXPORT_SYMBOL_GPL(blk_queue_flush);
 
+void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
+{
+	q->flush_not_queueable = !queueable;
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
+
 static int __init blk_settings_init(void)
 {
 	blk_max_low_pfn = max_low_pfn - 1;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index bd23631..d935bd8 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -152,7 +152,8 @@
 
 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
 {
-	return queue_var_show(q->limits.max_discard_sectors << 9, page);
+	return sprintf(page, "%llu\n",
+		       (unsigned long long)q->limits.max_discard_sectors << 9);
 }
 
 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 252a81a..a62be8d0 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -78,6 +78,8 @@
 
 	/* Some throttle limits got updated for the group */
 	int limits_changed;
+
+	struct rcu_head rcu_head;
 };
 
 struct throtl_data
@@ -88,7 +90,7 @@
 	/* service tree for active throtl groups */
 	struct throtl_rb_root tg_service_tree;
 
-	struct throtl_grp root_tg;
+	struct throtl_grp *root_tg;
 	struct request_queue *queue;
 
 	/* Total Number of queued bios on READ and WRITE lists */
@@ -151,56 +153,44 @@
 	return tg;
 }
 
+static void throtl_free_tg(struct rcu_head *head)
+{
+	struct throtl_grp *tg;
+
+	tg = container_of(head, struct throtl_grp, rcu_head);
+	free_percpu(tg->blkg.stats_cpu);
+	kfree(tg);
+}
+
 static void throtl_put_tg(struct throtl_grp *tg)
 {
 	BUG_ON(atomic_read(&tg->ref) <= 0);
 	if (!atomic_dec_and_test(&tg->ref))
 		return;
-	kfree(tg);
+
+	/*
+	 * A group is freed in rcu manner. But having an rcu lock does not
+	 * mean that one can access all the fields of blkg and assume these
+	 * are valid. For example, don't try to follow throtl_data and
+	 * request queue links.
+	 *
+	 * Having a reference to blkg under an rcu allows acess to only
+	 * values local to groups like group stats and group rate limits
+	 */
+	call_rcu(&tg->rcu_head, throtl_free_tg);
 }
 
-static struct throtl_grp * throtl_find_alloc_tg(struct throtl_data *td,
-			struct blkio_cgroup *blkcg)
+static void throtl_init_group(struct throtl_grp *tg)
 {
-	struct throtl_grp *tg = NULL;
-	void *key = td;
-	struct backing_dev_info *bdi = &td->queue->backing_dev_info;
-	unsigned int major, minor;
-
-	/*
-	 * TODO: Speed up blkiocg_lookup_group() by maintaining a radix
-	 * tree of blkg (instead of traversing through hash list all
-	 * the time.
-	 */
-
-	/*
-	 * This is the common case when there are no blkio cgroups.
- 	 * Avoid lookup in this case
- 	 */
-	if (blkcg == &blkio_root_cgroup)
-		tg = &td->root_tg;
-	else
-		tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
-
-	/* Fill in device details for root group */
-	if (tg && !tg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
-		sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
-		tg->blkg.dev = MKDEV(major, minor);
-		goto done;
-	}
-
-	if (tg)
-		goto done;
-
-	tg = kzalloc_node(sizeof(*tg), GFP_ATOMIC, td->queue->node);
-	if (!tg)
-		goto done;
-
 	INIT_HLIST_NODE(&tg->tg_node);
 	RB_CLEAR_NODE(&tg->rb_node);
 	bio_list_init(&tg->bio_lists[0]);
 	bio_list_init(&tg->bio_lists[1]);
-	td->limits_changed = false;
+	tg->limits_changed = false;
+
+	/* Practically unlimited BW */
+	tg->bps[0] = tg->bps[1] = -1;
+	tg->iops[0] = tg->iops[1] = -1;
 
 	/*
 	 * Take the initial reference that will be released on destroy
@@ -209,33 +199,181 @@
 	 * exit or cgroup deletion path depending on who is exiting first.
 	 */
 	atomic_set(&tg->ref, 1);
+}
+
+/* Should be called with rcu read lock held (needed for blkcg) */
+static void
+throtl_add_group_to_td_list(struct throtl_data *td, struct throtl_grp *tg)
+{
+	hlist_add_head(&tg->tg_node, &td->tg_list);
+	td->nr_undestroyed_grps++;
+}
+
+static void
+__throtl_tg_fill_dev_details(struct throtl_data *td, struct throtl_grp *tg)
+{
+	struct backing_dev_info *bdi = &td->queue->backing_dev_info;
+	unsigned int major, minor;
+
+	if (!tg || tg->blkg.dev)
+		return;
+
+	/*
+	 * Fill in device details for a group which might not have been
+	 * filled at group creation time as queue was being instantiated
+	 * and driver had not attached a device yet
+	 */
+	if (bdi->dev && dev_name(bdi->dev)) {
+		sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
+		tg->blkg.dev = MKDEV(major, minor);
+	}
+}
+
+/*
+ * Should be called with without queue lock held. Here queue lock will be
+ * taken rarely. It will be taken only once during life time of a group
+ * if need be
+ */
+static void
+throtl_tg_fill_dev_details(struct throtl_data *td, struct throtl_grp *tg)
+{
+	if (!tg || tg->blkg.dev)
+		return;
+
+	spin_lock_irq(td->queue->queue_lock);
+	__throtl_tg_fill_dev_details(td, tg);
+	spin_unlock_irq(td->queue->queue_lock);
+}
+
+static void throtl_init_add_tg_lists(struct throtl_data *td,
+			struct throtl_grp *tg, struct blkio_cgroup *blkcg)
+{
+	__throtl_tg_fill_dev_details(td, tg);
 
 	/* Add group onto cgroup list */
-	sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
 	blkiocg_add_blkio_group(blkcg, &tg->blkg, (void *)td,
-				MKDEV(major, minor), BLKIO_POLICY_THROTL);
+				tg->blkg.dev, BLKIO_POLICY_THROTL);
 
 	tg->bps[READ] = blkcg_get_read_bps(blkcg, tg->blkg.dev);
 	tg->bps[WRITE] = blkcg_get_write_bps(blkcg, tg->blkg.dev);
 	tg->iops[READ] = blkcg_get_read_iops(blkcg, tg->blkg.dev);
 	tg->iops[WRITE] = blkcg_get_write_iops(blkcg, tg->blkg.dev);
 
-	hlist_add_head(&tg->tg_node, &td->tg_list);
-	td->nr_undestroyed_grps++;
-done:
+	throtl_add_group_to_td_list(td, tg);
+}
+
+/* Should be called without queue lock and outside of rcu period */
+static struct throtl_grp *throtl_alloc_tg(struct throtl_data *td)
+{
+	struct throtl_grp *tg = NULL;
+	int ret;
+
+	tg = kzalloc_node(sizeof(*tg), GFP_ATOMIC, td->queue->node);
+	if (!tg)
+		return NULL;
+
+	ret = blkio_alloc_blkg_stats(&tg->blkg);
+
+	if (ret) {
+		kfree(tg);
+		return NULL;
+	}
+
+	throtl_init_group(tg);
 	return tg;
 }
 
-static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
+static struct
+throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg)
 {
 	struct throtl_grp *tg = NULL;
+	void *key = td;
+
+	/*
+	 * This is the common case when there are no blkio cgroups.
+ 	 * Avoid lookup in this case
+ 	 */
+	if (blkcg == &blkio_root_cgroup)
+		tg = td->root_tg;
+	else
+		tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
+
+	__throtl_tg_fill_dev_details(td, tg);
+	return tg;
+}
+
+/*
+ * This function returns with queue lock unlocked in case of error, like
+ * request queue is no more
+ */
+static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
+{
+	struct throtl_grp *tg = NULL, *__tg = NULL;
 	struct blkio_cgroup *blkcg;
+	struct request_queue *q = td->queue;
 
 	rcu_read_lock();
 	blkcg = task_blkio_cgroup(current);
-	tg = throtl_find_alloc_tg(td, blkcg);
-	if (!tg)
-		tg = &td->root_tg;
+	tg = throtl_find_tg(td, blkcg);
+	if (tg) {
+		rcu_read_unlock();
+		return tg;
+	}
+
+	/*
+	 * Need to allocate a group. Allocation of group also needs allocation
+	 * of per cpu stats which in-turn takes a mutex() and can block. Hence
+	 * we need to drop rcu lock and queue_lock before we call alloc
+	 *
+	 * Take the request queue reference to make sure queue does not
+	 * go away once we return from allocation.
+	 */
+	blk_get_queue(q);
+	rcu_read_unlock();
+	spin_unlock_irq(q->queue_lock);
+
+	tg = throtl_alloc_tg(td);
+	/*
+	 * We might have slept in group allocation. Make sure queue is not
+	 * dead
+	 */
+	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+		blk_put_queue(q);
+		if (tg)
+			kfree(tg);
+
+		return ERR_PTR(-ENODEV);
+	}
+	blk_put_queue(q);
+
+	/* Group allocated and queue is still alive. take the lock */
+	spin_lock_irq(q->queue_lock);
+
+	/*
+	 * Initialize the new group. After sleeping, read the blkcg again.
+	 */
+	rcu_read_lock();
+	blkcg = task_blkio_cgroup(current);
+
+	/*
+	 * If some other thread already allocated the group while we were
+	 * not holding queue lock, free up the group
+	 */
+	__tg = throtl_find_tg(td, blkcg);
+
+	if (__tg) {
+		kfree(tg);
+		rcu_read_unlock();
+		return __tg;
+	}
+
+	/* Group allocation failed. Account the IO to root group */
+	if (!tg) {
+		tg = td->root_tg;
+		return tg;
+	}
+
+	throtl_init_add_tg_lists(td, tg, blkcg);
 	rcu_read_unlock();
 	return tg;
 }
@@ -544,6 +682,12 @@
 	return 0;
 }
 
+static bool tg_no_rule_group(struct throtl_grp *tg, bool rw) {
+	if (tg->bps[rw] == -1 && tg->iops[rw] == -1)
+		return 1;
+	return 0;
+}
+
 /*
  * Returns whether one can dispatch a bio or not. Also returns approx number
  * of jiffies to wait before this bio is with-in IO rate and can be dispatched
@@ -608,10 +752,6 @@
 	tg->bytes_disp[rw] += bio->bi_size;
 	tg->io_disp[rw]++;
 
-	/*
-	 * TODO: This will take blkg->stats_lock. Figure out a way
-	 * to avoid this cost.
-	 */
 	blkiocg_update_dispatch_stats(&tg->blkg, bio->bi_size, rw, sync);
 }
 
@@ -989,15 +1129,51 @@
 	struct throtl_grp *tg;
 	struct bio *bio = *biop;
 	bool rw = bio_data_dir(bio), update_disptime = true;
+	struct blkio_cgroup *blkcg;
 
 	if (bio->bi_rw & REQ_THROTTLED) {
 		bio->bi_rw &= ~REQ_THROTTLED;
 		return 0;
 	}
 
+	/*
+	 * A throtl_grp pointer retrieved under rcu can be used to access
+	 * basic fields like stats and io rates. If a group has no rules,
+	 * just update the dispatch stats in lockless manner and return.
+	 */
+
+	rcu_read_lock();
+	blkcg = task_blkio_cgroup(current);
+	tg = throtl_find_tg(td, blkcg);
+	if (tg) {
+		throtl_tg_fill_dev_details(td, tg);
+
+		if (tg_no_rule_group(tg, rw)) {
+			blkiocg_update_dispatch_stats(&tg->blkg, bio->bi_size,
+					rw, bio->bi_rw & REQ_SYNC);
+			rcu_read_unlock();
+			return 0;
+		}
+	}
+	rcu_read_unlock();
+
+	/*
+	 * Either group has not been allocated yet or it is not an unlimited
+	 * IO group
+	 */
+
 	spin_lock_irq(q->queue_lock);
 	tg = throtl_get_tg(td);
 
+	if (IS_ERR(tg)) {
+		if (PTR_ERR(tg)	== -ENODEV) {
+			/*
+			 * Queue is gone. No queue lock held here.
+			 */
+			return -ENODEV;
+		}
+	}
+
 	if (tg->nr_queued[rw]) {
 		/*
 		 * There is already another bio queued in same dir. No
@@ -1060,39 +1236,24 @@
 	INIT_HLIST_HEAD(&td->tg_list);
 	td->tg_service_tree = THROTL_RB_ROOT;
 	td->limits_changed = false;
-
-	/* Init root group */
-	tg = &td->root_tg;
-	INIT_HLIST_NODE(&tg->tg_node);
-	RB_CLEAR_NODE(&tg->rb_node);
-	bio_list_init(&tg->bio_lists[0]);
-	bio_list_init(&tg->bio_lists[1]);
-
-	/* Practically unlimited BW */
-	tg->bps[0] = tg->bps[1] = -1;
-	tg->iops[0] = tg->iops[1] = -1;
-	td->limits_changed = false;
-
-	/*
-	 * Set root group reference to 2. One reference will be dropped when
-	 * all groups on tg_list are being deleted during queue exit. Other
-	 * reference will remain there as we don't want to delete this group
-	 * as it is statically allocated and gets destroyed when throtl_data
-	 * goes away.
-	 */
-	atomic_set(&tg->ref, 2);
-	hlist_add_head(&tg->tg_node, &td->tg_list);
-	td->nr_undestroyed_grps++;
-
 	INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work);
 
+	/* alloc and Init root group. */
+	td->queue = q;
+	tg = throtl_alloc_tg(td);
+
+	if (!tg) {
+		kfree(td);
+		return -ENOMEM;
+	}
+
+	td->root_tg = tg;
+
 	rcu_read_lock();
-	blkiocg_add_blkio_group(&blkio_root_cgroup, &tg->blkg, (void *)td,
-					0, BLKIO_POLICY_THROTL);
+	throtl_init_add_tg_lists(td, tg, &blkio_root_cgroup);
 	rcu_read_unlock();
 
 	/* Attach throtl data to request queue */
-	td->queue = q;
 	q->td = td;
 	return 0;
 }
diff --git a/block/blk.h b/block/blk.h
index 4df474d..d658628 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -62,6 +62,26 @@
 			return rq;
 		}
 
+		/*
+		 * Flush request is running and flush request isn't queueable
+		 * in the drive, we can hold the queue till flush request is
+		 * finished. Even we don't do this, driver can't dispatch next
+		 * requests and will requeue them. And this can improve
+		 * throughput too. For example, we have request flush1, write1,
+		 * flush 2. flush1 is dispatched, then queue is hold, write1
+		 * isn't inserted to queue. After flush1 is finished, flush2
+		 * will be dispatched. Since disk cache is already clean,
+		 * flush2 will be finished very soon, so looks like flush2 is
+		 * folded to flush1.
+		 * Since the queue is hold, a flag is set to indicate the queue
+		 * should be restarted later. Please see flush_end_io() for
+		 * details.
+		 */
+		if (q->flush_pending_idx != q->flush_running_idx &&
+				!queue_flush_queueable(q)) {
+			q->flush_queue_delayed = 1;
+			return NULL;
+		}
 		if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) ||
 		    !q->elevator->ops->elevator_dispatch_fn(q, 0))
 			return NULL;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ab7a9e6..d646b27 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -300,7 +300,9 @@
 
 	/* List of cfq groups being managed on this device*/
 	struct hlist_head cfqg_list;
-	struct rcu_head rcu;
+
+	/* Number of groups which are on blkcg->blkg_list */
+	unsigned int nr_blkcg_linked_grps;
 };
 
 static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
@@ -1014,28 +1016,47 @@
 	cfqg->needs_update = true;
 }
 
-static struct cfq_group * cfq_find_alloc_cfqg(struct cfq_data *cfqd,
-		struct blkio_cgroup *blkcg, int create)
+static void cfq_init_add_cfqg_lists(struct cfq_data *cfqd,
+			struct cfq_group *cfqg, struct blkio_cgroup *blkcg)
 {
-	struct cfq_group *cfqg = NULL;
-	void *key = cfqd;
-	int i, j;
-	struct cfq_rb_root *st;
 	struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;
 	unsigned int major, minor;
 
-	cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
-	if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
+	/*
+	 * Add group onto cgroup list. It might happen that bdi->dev is
+	 * not initialized yet. Initialize this new group without major
+	 * and minor info and this info will be filled in once a new thread
+	 * comes for IO.
+	 */
+	if (bdi->dev) {
 		sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
-		cfqg->blkg.dev = MKDEV(major, minor);
-		goto done;
-	}
-	if (cfqg || !create)
-		goto done;
+		cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg,
+					(void *)cfqd, MKDEV(major, minor));
+	} else
+		cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg,
+					(void *)cfqd, 0);
+
+	cfqd->nr_blkcg_linked_grps++;
+	cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);
+
+	/* Add group on cfqd list */
+	hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
+}
+
+/*
+ * Should be called from sleepable context. No request queue lock as per
+ * cpu stats are allocated dynamically and alloc_percpu needs to be called
+ * from sleepable context.
+ */
+static struct cfq_group * cfq_alloc_cfqg(struct cfq_data *cfqd)
+{
+	struct cfq_group *cfqg = NULL;
+	int i, j, ret;
+	struct cfq_rb_root *st;
 
 	cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node);
 	if (!cfqg)
-		goto done;
+		return NULL;
 
 	for_each_cfqg_st(cfqg, i, j, st)
 		*st = CFQ_RB_ROOT;
@@ -1049,43 +1070,94 @@
 	 */
 	cfqg->ref = 1;
 
+	ret = blkio_alloc_blkg_stats(&cfqg->blkg);
+	if (ret) {
+		kfree(cfqg);
+		return NULL;
+	}
+
+	return cfqg;
+}
+
+static struct cfq_group *
+cfq_find_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg)
+{
+	struct cfq_group *cfqg = NULL;
+	void *key = cfqd;
+	struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;
+	unsigned int major, minor;
+
 	/*
-	 * Add group onto cgroup list. It might happen that bdi->dev is
-	 * not initialized yet. Initialize this new group without major
-	 * and minor info and this info will be filled in once a new thread
-	 * comes for IO. See code above.
+	 * This is the common case when there are no blkio cgroups.
+	 * Avoid lookup in this case
 	 */
-	if (bdi->dev) {
+	if (blkcg == &blkio_root_cgroup)
+		cfqg = &cfqd->root_group;
+	else
+		cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
+
+	if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
 		sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
-		cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
-					MKDEV(major, minor));
-	} else
-		cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
-					0);
+		cfqg->blkg.dev = MKDEV(major, minor);
+	}
 
-	cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);
-
-	/* Add group on cfqd list */
-	hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
-
-done:
 	return cfqg;
 }
 
 /*
- * Search for the cfq group current task belongs to. If create = 1, then also
- * create the cfq group if it does not exist. request_queue lock must be held.
+ * Search for the cfq group current task belongs to. request_queue lock must
+ * be held.
  */
-static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
+static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd)
 {
 	struct blkio_cgroup *blkcg;
-	struct cfq_group *cfqg = NULL;
+	struct cfq_group *cfqg = NULL, *__cfqg = NULL;
+	struct request_queue *q = cfqd->queue;
 
 	rcu_read_lock();
 	blkcg = task_blkio_cgroup(current);
-	cfqg = cfq_find_alloc_cfqg(cfqd, blkcg, create);
-	if (!cfqg && create)
+	cfqg = cfq_find_cfqg(cfqd, blkcg);
+	if (cfqg) {
+		rcu_read_unlock();
+		return cfqg;
+	}
+
+	/*
+	 * Need to allocate a group. Allocation of group also needs allocation
+	 * of per cpu stats which in-turn takes a mutex() and can block. Hence
+	 * we need to drop rcu lock and queue_lock before we call alloc.
+	 *
+	 * Not taking any queue reference here and assuming that queue is
+	 * around by the time we return. CFQ queue allocation code does
+	 * the same. It might be racy though.
+	 */
+
+	rcu_read_unlock();
+	spin_unlock_irq(q->queue_lock);
+
+	cfqg = cfq_alloc_cfqg(cfqd);
+
+	spin_lock_irq(q->queue_lock);
+
+	rcu_read_lock();
+	blkcg = task_blkio_cgroup(current);
+
+	/*
+	 * If some other thread already allocated the group while we were
+	 * not holding queue lock, free up the group
+	 */
+	__cfqg = cfq_find_cfqg(cfqd, blkcg);
+
+	if (__cfqg) {
+		kfree(cfqg);
+		rcu_read_unlock();
+		return __cfqg;
+	}
+
+	if (!cfqg)
 		cfqg = &cfqd->root_group;
+
+	cfq_init_add_cfqg_lists(cfqd, cfqg, blkcg);
 	rcu_read_unlock();
 	return cfqg;
 }
@@ -1118,6 +1190,7 @@
 		return;
 	for_each_cfqg_st(cfqg, i, j, st)
 		BUG_ON(!RB_EMPTY_ROOT(&st->rb));
+	free_percpu(cfqg->blkg.stats_cpu);
 	kfree(cfqg);
 }
 
@@ -1176,7 +1249,7 @@
 }
 
 #else /* GROUP_IOSCHED */
-static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
+static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd)
 {
 	return &cfqd->root_group;
 }
@@ -2911,7 +2984,7 @@
 	struct cfq_group *cfqg;
 
 retry:
-	cfqg = cfq_get_cfqg(cfqd, 1);
+	cfqg = cfq_get_cfqg(cfqd);
 	cic = cfq_cic_lookup(cfqd, ioc);
 	/* cic always exists here */
 	cfqq = cic_to_cfqq(cic, is_sync);
@@ -3815,15 +3888,11 @@
 		cfq_put_queue(cfqd->async_idle_cfqq);
 }
 
-static void cfq_cfqd_free(struct rcu_head *head)
-{
-	kfree(container_of(head, struct cfq_data, rcu));
-}
-
 static void cfq_exit_queue(struct elevator_queue *e)
 {
 	struct cfq_data *cfqd = e->elevator_data;
 	struct request_queue *q = cfqd->queue;
+	bool wait = false;
 
 	cfq_shutdown_timer_wq(cfqd);
 
@@ -3842,7 +3911,13 @@
 
 	cfq_put_async_queues(cfqd);
 	cfq_release_cfq_groups(cfqd);
-	cfq_blkiocg_del_blkio_group(&cfqd->root_group.blkg);
+
+	/*
+	 * If there are groups which we could not unlink from blkcg list,
+	 * wait for a rcu period for them to be freed.
+	 */
+	if (cfqd->nr_blkcg_linked_grps)
+		wait = true;
 
 	spin_unlock_irq(q->queue_lock);
 
@@ -3852,8 +3927,20 @@
 	ida_remove(&cic_index_ida, cfqd->cic_index);
 	spin_unlock(&cic_index_lock);
 
-	/* Wait for cfqg->blkg->key accessors to exit their grace periods. */
-	call_rcu(&cfqd->rcu, cfq_cfqd_free);
+	/*
+	 * Wait for cfqg->blkg->key accessors to exit their grace periods.
+	 * Do this wait only if there are other unlinked groups out
+	 * there. This can happen if cgroup deletion path claimed the
+	 * responsibility of cleaning up a group before queue cleanup code
+	 * get to the group.
+	 *
+	 * Do not call synchronize_rcu() unconditionally as there are drivers
+	 * which create/delete request queue hundreds of times during scan/boot
+	 * and synchronize_rcu() can take significant time and slow down boot.
+	 */
+	if (wait)
+		synchronize_rcu();
+	kfree(cfqd);
 }
 
 static int cfq_alloc_cic_index(void)
@@ -3909,14 +3996,29 @@
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
 	/*
-	 * Take a reference to root group which we never drop. This is just
-	 * to make sure that cfq_put_cfqg() does not try to kfree root group
+	 * Set root group reference to 2. One reference will be dropped when
+	 * all groups on cfqd->cfqg_list are being deleted during queue exit.
+	 * Other reference will remain there as we don't want to delete this
+	 * group as it is statically allocated and gets destroyed when
+	 * throtl_data goes away.
 	 */
-	cfqg->ref = 1;
+	cfqg->ref = 2;
+
+	if (blkio_alloc_blkg_stats(&cfqg->blkg)) {
+		kfree(cfqg);
+		kfree(cfqd);
+		return NULL;
+	}
+
 	rcu_read_lock();
+
 	cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg,
 					(void *)cfqd, 0);
 	rcu_read_unlock();
+	cfqd->nr_blkcg_linked_grps++;
+
+	/* Add group on cfqd->cfqg_list */
+	hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
 #endif
 	/*
 	 * Not strictly needed (since RB_ROOT just clears the node and we
diff --git a/block/elevator.c b/block/elevator.c
index 45ca1e3..2a0b653 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -155,13 +155,8 @@
 
 	e = elevator_find(name);
 	if (!e) {
-		char elv[ELV_NAME_MAX + strlen("-iosched")];
-
 		spin_unlock(&elv_list_lock);
-
-		snprintf(elv, sizeof(elv), "%s-iosched", name);
-
-		request_module("%s", elv);
+		request_module("%s-iosched", name);
 		spin_lock(&elv_list_lock);
 		e = elevator_find(name);
 	}
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index e2f57e9e..dad2c95 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1089,21 +1089,21 @@
 static int ata_scsi_dev_config(struct scsi_device *sdev,
 			       struct ata_device *dev)
 {
+	struct request_queue *q = sdev->request_queue;
+
 	if (!ata_id_has_unload(dev->id))
 		dev->flags |= ATA_DFLAG_NO_UNLOAD;
 
 	/* configure max sectors */
-	blk_queue_max_hw_sectors(sdev->request_queue, dev->max_sectors);
+	blk_queue_max_hw_sectors(q, dev->max_sectors);
 
 	if (dev->class == ATA_DEV_ATAPI) {
-		struct request_queue *q = sdev->request_queue;
 		void *buf;
 
 		sdev->sector_size = ATA_SECT_SIZE;
 
 		/* set DMA padding */
-		blk_queue_update_dma_pad(sdev->request_queue,
-					 ATA_DMA_PAD_SZ - 1);
+		blk_queue_update_dma_pad(q, ATA_DMA_PAD_SZ - 1);
 
 		/* configure draining */
 		buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);
@@ -1131,8 +1131,7 @@
 			"sector_size=%u > PAGE_SIZE, PIO may malfunction\n",
 			sdev->sector_size);
 
-	blk_queue_update_dma_alignment(sdev->request_queue,
-				       sdev->sector_size - 1);
+	blk_queue_update_dma_alignment(q, sdev->sector_size - 1);
 
 	if (dev->flags & ATA_DFLAG_AN)
 		set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);
@@ -1145,6 +1144,8 @@
 		scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
 	}
 
+	blk_queue_flush_queueable(q, false);
+
 	dev->sdev = sdev;
 	return 0;
 }
diff --git a/drivers/atm/fore200e.c b/drivers/atm/fore200e.c
index bdd2719..bc9e702 100644
--- a/drivers/atm/fore200e.c
+++ b/drivers/atm/fore200e.c
@@ -2643,16 +2643,19 @@
 }
 
 #ifdef CONFIG_SBUS
+static const struct of_device_id fore200e_sba_match[];
 static int __devinit fore200e_sba_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	const struct fore200e_bus *bus;
 	struct fore200e *fore200e;
 	static int index = 0;
 	int err;
 
-	if (!op->dev.of_match)
+	match = of_match_device(fore200e_sba_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	bus = op->dev.of_match->data;
+	bus = match->data;
 
 	fore200e = kzalloc(sizeof(struct fore200e), GFP_KERNEL);
 	if (!fore200e)
diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index 8690e31..a0aabd9 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -320,6 +320,8 @@
 		disk->first_minor = unit;
 		strcpy(disk->disk_name, cd->name);	/* umm... */
 		disk->fops = &pcd_bdops;
+		disk->flags = GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
+		disk->events = DISK_EVENT_MEDIA_CHANGE;
 	}
 }
 
diff --git a/drivers/cdrom/viocd.c b/drivers/cdrom/viocd.c
index e427fbe..ae15a4d 100644
--- a/drivers/cdrom/viocd.c
+++ b/drivers/cdrom/viocd.c
@@ -625,7 +625,9 @@
 	blk_queue_max_hw_sectors(q, 4096 / 512);
 	gendisk->queue = q;
 	gendisk->fops = &viocd_fops;
-	gendisk->flags = GENHD_FL_CD|GENHD_FL_REMOVABLE;
+	gendisk->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE |
+			 GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
+	gendisk->events = DISK_EVENT_MEDIA_CHANGE;
 	set_capacity(gendisk, 0);
 	gendisk->private_data = d;
 	d->viocd_disk = gendisk;
diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
index 43ac619..ac6739e 100644
--- a/drivers/char/hw_random/n2-drv.c
+++ b/drivers/char/hw_random/n2-drv.c
@@ -619,15 +619,18 @@
 		pr_info("%s", version);
 }
 
+static const struct of_device_id n2rng_match[];
 static int __devinit n2rng_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	int victoria_falls;
 	int err = -ENOMEM;
 	struct n2rng *np;
 
-	if (!op->dev.of_match)
+	match = of_match_device(n2rng_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	victoria_falls = (op->dev.of_match->data != NULL);
+	victoria_falls = (match->data != NULL);
 
 	n2rng_driver_version();
 	np = kzalloc(sizeof(*np), GFP_KERNEL);
diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index cc6c9b2..64c6b85 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -2554,9 +2554,11 @@
 };
 #endif /* CONFIG_PCI */
 
+static struct of_device_id ipmi_match[];
 static int __devinit ipmi_probe(struct platform_device *dev)
 {
 #ifdef CONFIG_OF
+	const struct of_device_id *match;
 	struct smi_info *info;
 	struct resource resource;
 	const __be32 *regsize, *regspacing, *regshift;
@@ -2566,7 +2568,8 @@
 
 	dev_info(&dev->dev, "probing via device tree\n");
 
-	if (!dev->dev.of_match)
+	match = of_match_device(ipmi_match, &dev->dev);
+	if (!match)
 		return -EINVAL;
 
 	ret = of_address_to_resource(np, 0, &resource);
@@ -2601,7 +2604,7 @@
 		return -ENOMEM;
 	}
 
-	info->si_type		= (enum si_type) dev->dev.of_match->data;
+	info->si_type		= (enum si_type) match->data;
 	info->addr_source	= SI_DEVICETREE;
 	info->irq_setup		= std_irq_setup;
 
diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.c b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
index d6412c1..39ccdea 100644
--- a/drivers/char/xilinx_hwicap/xilinx_hwicap.c
+++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
@@ -715,13 +715,13 @@
 }
 
 #ifdef CONFIG_OF
-static int __devinit hwicap_of_probe(struct platform_device *op)
+static int __devinit hwicap_of_probe(struct platform_device *op,
+				     const struct hwicap_driver_config *config)
 {
 	struct resource res;
 	const unsigned int *id;
 	const char *family;
 	int rc;
-	const struct hwicap_driver_config *config = op->dev.of_match->data;
 	const struct config_registers *regs;
 
 
@@ -751,20 +751,24 @@
 			regs);
 }
 #else
-static inline int hwicap_of_probe(struct platform_device *op)
+static inline int hwicap_of_probe(struct platform_device *op,
+				  const struct hwicap_driver_config *config)
 {
 	return -EINVAL;
 }
 #endif /* CONFIG_OF */
 
+static const struct of_device_id __devinitconst hwicap_of_match[];
 static int __devinit hwicap_drv_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *match;
 	struct resource *res;
 	const struct config_registers *regs;
 	const char *family;
 
-	if (pdev->dev.of_match)
-		return hwicap_of_probe(pdev);
+	match = of_match_device(hwicap_of_match, &pdev->dev);
+	if (match)
+		return hwicap_of_probe(pdev, match->data);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
diff --git a/drivers/edac/ppc4xx_edac.c b/drivers/edac/ppc4xx_edac.c
index c1f0045..af8e7b1 100644
--- a/drivers/edac/ppc4xx_edac.c
+++ b/drivers/edac/ppc4xx_edac.c
@@ -1019,7 +1019,7 @@
 	struct ppc4xx_edac_pdata *pdata = NULL;
 	const struct device_node *np = op->dev.of_node;
 
-	if (op->dev.of_match == NULL)
+	if (of_match_device(ppc4xx_edac_match, &op->dev) == NULL)
 		return -EINVAL;
 
 	/* Initial driver pointers and private data */
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 75b984c..107397a 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -560,15 +560,18 @@
 	.timeout = HZ,
 };
 
+static const struct of_device_id mpc_i2c_of_match[];
 static int __devinit fsl_i2c_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	struct mpc_i2c *i2c;
 	const u32 *prop;
 	u32 clock = MPC_I2C_CLOCK_LEGACY;
 	int result = 0;
 	int plen;
 
-	if (!op->dev.of_match)
+	match = of_match_device(mpc_i2c_of_match, &op->dev);
+	if (!match)
 		return -EINVAL;
 
 	i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
@@ -605,8 +608,8 @@
 			clock = *prop;
 	}
 
-	if (op->dev.of_match->data) {
-		struct mpc_i2c_data *data = op->dev.of_match->data;
+	if (match->data) {
+		struct mpc_i2c_data *data = match->data;
 		data->setup(op->dev.of_node, i2c, clock, data->prescaler);
 	} else {
 		/* Backwards compatibility */
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index a5ec5a7c..6e5123b 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1781,7 +1781,8 @@
 
 	ide_cd_read_toc(drive, &sense);
 	g->fops = &idecd_ops;
-	g->flags |= GENHD_FL_REMOVABLE;
+	g->flags |= GENHD_FL_REMOVABLE | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
+	g->events = DISK_EVENT_MEDIA_CHANGE;
 	add_disk(g);
 	return 0;
 
diff --git a/drivers/mmc/host/sdhci-of-core.c b/drivers/mmc/host/sdhci-of-core.c
index f9b611f..60e4186 100644
--- a/drivers/mmc/host/sdhci-of-core.c
+++ b/drivers/mmc/host/sdhci-of-core.c
@@ -124,8 +124,10 @@
 #endif
 }
 
+static const struct of_device_id sdhci_of_match[];
 static int __devinit sdhci_of_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct sdhci_of_data *sdhci_of_data;
 	struct sdhci_host *host;
@@ -134,9 +136,10 @@
 	int size;
 	int ret;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(sdhci_of_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	sdhci_of_data = ofdev->dev.of_match->data;
+	sdhci_of_data = match->data;
 
 	if (!of_device_is_available(np))
 		return -ENODEV;
diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index bd483f0..c1d3346 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -214,11 +214,13 @@
 }
 #endif
 
+static struct of_device_id of_flash_match[];
 static int __devinit of_flash_probe(struct platform_device *dev)
 {
 #ifdef CONFIG_MTD_PARTITIONS
 	const char **part_probe_types;
 #endif
+	const struct of_device_id *match;
 	struct device_node *dp = dev->dev.of_node;
 	struct resource res;
 	struct of_flash *info;
@@ -232,9 +234,10 @@
 	struct mtd_info **mtd_list = NULL;
 	resource_size_t res_size;
 
-	if (!dev->dev.of_match)
+	match = of_match_device(of_flash_match, &dev->dev);
+	if (!match)
 		return -EINVAL;
-	probe_type = dev->dev.of_match->data;
+	probe_type = match->data;
 
 	reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
 
diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
index bd1d811..5fedc33 100644
--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -247,8 +247,10 @@
 }
 #endif /* CONFIG_PPC_MPC512x */
 
+static struct of_device_id mpc5xxx_can_table[];
 static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct mpc5xxx_can_data *data;
 	struct device_node *np = ofdev->dev.of_node;
 	struct net_device *dev;
@@ -258,9 +260,10 @@
 	int irq, mscan_clksrc = 0;
 	int err = -ENOMEM;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	data = (struct mpc5xxx_can_data *)ofdev->dev.of_match->data;
+	data = match->data;
 
 	base = of_iomap(np, 0);
 	if (!base) {
diff --git a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c
index 24cb953..5131e61 100644
--- a/drivers/net/fs_enet/fs_enet-main.c
+++ b/drivers/net/fs_enet/fs_enet-main.c
@@ -998,8 +998,10 @@
 #endif
 };
 
+static struct of_device_id fs_enet_match[];
 static int __devinit fs_enet_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct net_device *ndev;
 	struct fs_enet_private *fep;
 	struct fs_platform_info *fpi;
@@ -1007,14 +1009,15 @@
 	const u8 *mac_addr;
 	int privsize, len, ret = -ENODEV;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(fs_enet_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
 	fpi = kzalloc(sizeof(*fpi), GFP_KERNEL);
 	if (!fpi)
 		return -ENOMEM;
 
-	if (!IS_FEC(ofdev->dev.of_match)) {
+	if (!IS_FEC(match)) {
 		data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
 		if (!data || len != 4)
 			goto out_free_fpi;
@@ -1049,7 +1052,7 @@
 	fep->dev = &ofdev->dev;
 	fep->ndev = ndev;
 	fep->fpi = fpi;
-	fep->ops = ofdev->dev.of_match->data;
+	fep->ops = match->data;
 
 	ret = fep->ops->setup_data(ndev);
 	if (ret)
diff --git a/drivers/net/fs_enet/mii-fec.c b/drivers/net/fs_enet/mii-fec.c
index 7e840d3..6a2e150 100644
--- a/drivers/net/fs_enet/mii-fec.c
+++ b/drivers/net/fs_enet/mii-fec.c
@@ -101,17 +101,20 @@
 	return 0;
 }
 
+static struct of_device_id fs_enet_mdio_fec_match[];
 static int __devinit fs_enet_mdio_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct resource res;
 	struct mii_bus *new_bus;
 	struct fec_info *fec;
 	int (*get_bus_freq)(struct device_node *);
 	int ret = -ENOMEM, clock, speed;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(fs_enet_mdio_fec_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	get_bus_freq = ofdev->dev.of_match->data;
+	get_bus_freq = match->data;
 
 	new_bus = mdiobus_alloc();
 	if (!new_bus)
diff --git a/drivers/net/sunhme.c b/drivers/net/sunhme.c
index eb4f59f..bff2f79 100644
--- a/drivers/net/sunhme.c
+++ b/drivers/net/sunhme.c
@@ -3237,15 +3237,18 @@
 #endif
 
 #ifdef CONFIG_SBUS
+static const struct of_device_id hme_sbus_match[];
 static int __devinit hme_sbus_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	struct device_node *dp = op->dev.of_node;
 	const char *model = of_get_property(dp, "model", NULL);
 	int is_qfe;
 
-	if (!op->dev.of_match)
+	match = of_match_device(hme_sbus_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	is_qfe = (op->dev.of_match->data != NULL);
+	is_qfe = (match->data != NULL);
 
 	if (!is_qfe && model && !strcmp(model, "SUNW,sbus-qfe"))
 		is_qfe = 1;
diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index e2d45c9..9689d41c 100644
--- a/drivers/scsi/qlogicpti.c
+++ b/drivers/scsi/qlogicpti.c
@@ -1292,8 +1292,10 @@
 	.use_clustering		= ENABLE_CLUSTERING,
 };
 
+static const struct of_device_id qpti_match[];
 static int __devinit qpti_sbus_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	struct scsi_host_template *tpnt;
 	struct device_node *dp = op->dev.of_node;
 	struct Scsi_Host *host;
@@ -1301,9 +1303,10 @@
 	static int nqptis;
 	const char *fcode;
 
-	if (!op->dev.of_match)
+	match = of_match_device(qpti_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	tpnt = op->dev.of_match->data;
+	tpnt = match->data;
 
 	/* Sometimes Antares cards come up not completely
 	 * setup, and we get a report of a zero IRQ.
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 95019c7..4778e27 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -636,7 +636,7 @@
 	disk->first_minor = minor;
 	sprintf(disk->disk_name, "sr%d", minor);
 	disk->fops = &sr_bdops;
-	disk->flags = GENHD_FL_CD;
+	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 
 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 0e8eec5..c911b24 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -80,14 +80,17 @@
 /*
  * Try to register a serial port
  */
+static struct of_device_id of_platform_serial_table[];
 static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct of_serial_info *info;
 	struct uart_port port;
 	int port_type;
 	int ret;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(of_platform_serial_table, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
 	if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
@@ -97,7 +100,7 @@
 	if (info == NULL)
 		return -ENOMEM;
 
-	port_type = (unsigned long)ofdev->dev.of_match->data;
+	port_type = (unsigned long)match->data;
 	ret = of_platform_serial_setup(ofdev, port_type, &port);
 	if (ret)
 		goto out;
diff --git a/drivers/usb/gadget/fsl_qe_udc.c b/drivers/usb/gadget/fsl_qe_udc.c
index 36613b3..3a68e09 100644
--- a/drivers/usb/gadget/fsl_qe_udc.c
+++ b/drivers/usb/gadget/fsl_qe_udc.c
@@ -2539,15 +2539,18 @@
 }
 
 /* Driver probe functions */
+static const struct of_device_id qe_udc_match[];
 static int __devinit qe_udc_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct qe_ep *ep;
 	unsigned int ret = 0;
 	unsigned int i;
 	const void *prop;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(qe_udc_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
 	prop = of_get_property(np, "mode", NULL);
@@ -2561,7 +2564,7 @@
 		return -ENOMEM;
 	}
 
-	udc_controller->soc_type = (unsigned long)ofdev->dev.of_match->data;
+	udc_controller->soc_type = (unsigned long)match->data;
 	udc_controller->usb_regs = of_iomap(np, 0);
 	if (!udc_controller->usb_regs) {
 		ret = -ENOMEM;
diff --git a/drivers/watchdog/mpc8xxx_wdt.c b/drivers/watchdog/mpc8xxx_wdt.c
index 528bceb..eed5436f 100644
--- a/drivers/watchdog/mpc8xxx_wdt.c
+++ b/drivers/watchdog/mpc8xxx_wdt.c
@@ -185,17 +185,20 @@
 	.fops	= &mpc8xxx_wdt_fops,
 };
 
+static const struct of_device_id mpc8xxx_wdt_match[];
 static int __devinit mpc8xxx_wdt_probe(struct platform_device *ofdev)
 {
 	int ret;
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct mpc8xxx_wdt_type *wdt_type;
 	u32 freq = fsl_get_sys_freq();
 	bool enabled;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(mpc8xxx_wdt_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	wdt_type = ofdev->dev.of_match->data;
+	wdt_type = match->data;
 
 	if (!freq || freq == -1)
 		return -EINVAL;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 257b00e..d7c2e0f 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1237,6 +1237,8 @@
 	res = __blkdev_get(bdev, mode, 0);
 
 	if (whole) {
+		struct gendisk *disk = whole->bd_disk;
+
 		/* finish claiming */
 		mutex_lock(&bdev->bd_mutex);
 		spin_lock(&bdev_lock);
@@ -1263,15 +1265,16 @@
 		spin_unlock(&bdev_lock);
 
 		/*
-		 * Block event polling for write claims.  Any write
-		 * holder makes the write_holder state stick until all
-		 * are released.  This is good enough and tracking
-		 * individual writeable reference is too fragile given
-		 * the way @mode is used in blkdev_get/put().
+		 * Block event polling for write claims if requested.  Any
+		 * write holder makes the write_holder state stick until
+		 * all are released.  This is good enough and tracking
+		 * individual writeable reference is too fragile given the
+		 * way @mode is used in blkdev_get/put().
 		 */
-		if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
+		if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) &&
+		    !res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
 			bdev->bd_write_holder = true;
-			disk_block_events(bdev->bd_disk);
+			disk_block_events(disk);
 		}
 
 		mutex_unlock(&bdev->bd_mutex);
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 3313dd1..9a37a9b 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -53,11 +53,14 @@
 static void configfs_d_iput(struct dentry * dentry,
 			    struct inode * inode)
 {
-	struct configfs_dirent * sd = dentry->d_fsdata;
+	struct configfs_dirent *sd = dentry->d_fsdata;
 
 	if (sd) {
 		BUG_ON(sd->s_dentry != dentry);
+		/* Coordinate with configfs_readdir */
+		spin_lock(&configfs_dirent_lock);
 		sd->s_dentry = NULL;
+		spin_unlock(&configfs_dirent_lock);
 		configfs_put(sd);
 	}
 	iput(inode);
@@ -689,7 +692,8 @@
 			sd = child->d_fsdata;
 			sd->s_type |= CONFIGFS_USET_DEFAULT;
 		} else {
-			d_delete(child);
+			BUG_ON(child->d_inode);
+			d_drop(child);
 			dput(child);
 		}
 	}
@@ -1545,7 +1549,7 @@
 	struct configfs_dirent * parent_sd = dentry->d_fsdata;
 	struct configfs_dirent *cursor = filp->private_data;
 	struct list_head *p, *q = &cursor->s_sibling;
-	ino_t ino;
+	ino_t ino = 0;
 	int i = filp->f_pos;
 
 	switch (i) {
@@ -1573,6 +1577,7 @@
 				struct configfs_dirent *next;
 				const char * name;
 				int len;
+				struct inode *inode = NULL;
 
 				next = list_entry(p, struct configfs_dirent,
 						   s_sibling);
@@ -1581,9 +1586,28 @@
 
 				name = configfs_get_name(next);
 				len = strlen(name);
-				if (next->s_dentry)
-					ino = next->s_dentry->d_inode->i_ino;
-				else
+
+				/*
+				 * We'll have a dentry and an inode for
+				 * PINNED items and for open attribute
+				 * files.  We lock here to prevent a race
+				 * with configfs_d_iput() clearing
+				 * s_dentry before calling iput().
+				 *
+				 * Why do we go to the trouble?  If
+				 * someone has an attribute file open,
+				 * the inode number should match until
+				 * they close it.  Beyond that, we don't
+				 * care.
+				 */
+				spin_lock(&configfs_dirent_lock);
+				dentry = next->s_dentry;
+				if (dentry)
+					inode = dentry->d_inode;
+				if (inode)
+					ino = inode->i_ino;
+				spin_unlock(&configfs_dirent_lock);
+				if (!inode)
 					ino = iunique(configfs_sb, 2);
 
 				if (filldir(dirent, name, len, filp->f_pos, ino,
@@ -1683,7 +1707,8 @@
 		err = configfs_attach_group(sd->s_element, &group->cg_item,
 					    dentry);
 		if (err) {
-			d_delete(dentry);
+			BUG_ON(dentry->d_inode);
+			d_drop(dentry);
 			dput(dentry);
 		} else {
 			spin_lock(&configfs_dirent_lock);
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 6437202..9a3e6bb 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -539,25 +539,41 @@
 
 /* We want to make sure that nobody is heartbeating on top of us --
  * this will help detect an invalid configuration. */
-static int o2hb_check_last_timestamp(struct o2hb_region *reg)
+static void o2hb_check_last_timestamp(struct o2hb_region *reg)
 {
-	int node_num, ret;
 	struct o2hb_disk_slot *slot;
 	struct o2hb_disk_heartbeat_block *hb_block;
+	char *errstr;
 
-	node_num = o2nm_this_node();
-
-	ret = 1;
-	slot = &reg->hr_slots[node_num];
+	slot = &reg->hr_slots[o2nm_this_node()];
 	/* Don't check on our 1st timestamp */
-	if (slot->ds_last_time) {
-		hb_block = slot->ds_raw_block;
+	if (!slot->ds_last_time)
+		return;
 
-		if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time)
-			ret = 0;
-	}
+	hb_block = slot->ds_raw_block;
+	if (le64_to_cpu(hb_block->hb_seq) == slot->ds_last_time &&
+	    le64_to_cpu(hb_block->hb_generation) == slot->ds_last_generation &&
+	    hb_block->hb_node == slot->ds_node_num)
+		return;
 
-	return ret;
+#define ERRSTR1		"Another node is heartbeating on device"
+#define ERRSTR2		"Heartbeat generation mismatch on device"
+#define ERRSTR3		"Heartbeat sequence mismatch on device"
+
+	if (hb_block->hb_node != slot->ds_node_num)
+		errstr = ERRSTR1;
+	else if (le64_to_cpu(hb_block->hb_generation) !=
+		 slot->ds_last_generation)
+		errstr = ERRSTR2;
+	else
+		errstr = ERRSTR3;
+
+	mlog(ML_ERROR, "%s (%s): expected(%u:0x%llx, 0x%llx), "
+	     "ondisk(%u:0x%llx, 0x%llx)\n", errstr, reg->hr_dev_name,
+	     slot->ds_node_num, (unsigned long long)slot->ds_last_generation,
+	     (unsigned long long)slot->ds_last_time, hb_block->hb_node,
+	     (unsigned long long)le64_to_cpu(hb_block->hb_generation),
+	     (unsigned long long)le64_to_cpu(hb_block->hb_seq));
 }
 
 static inline void o2hb_prepare_block(struct o2hb_region *reg,
@@ -983,9 +999,7 @@
 	/* With an up to date view of the slots, we can check that no
 	 * other node has been improperly configured to heartbeat in
 	 * our slot. */
-	if (!o2hb_check_last_timestamp(reg))
-		mlog(ML_ERROR, "Device \"%s\": another node is heartbeating "
-		     "in our slot!\n", reg->hr_dev_name);
+	o2hb_check_last_timestamp(reg);
 
 	/* fill in the proper info for our next heartbeat */
 	o2hb_prepare_block(reg, reg->hr_generation);
@@ -999,8 +1013,8 @@
 	}
 
 	i = -1;
-	while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
-
+	while((i = find_next_bit(configured_nodes,
+				 O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
 		change |= o2hb_check_slot(reg, &reg->hr_slots[i]);
 	}
 
@@ -1690,6 +1704,7 @@
 	struct file *filp = NULL;
 	struct inode *inode = NULL;
 	ssize_t ret = -EINVAL;
+	int live_threshold;
 
 	if (reg->hr_bdev)
 		goto out;
@@ -1766,8 +1781,18 @@
 	 * A node is considered live after it has beat LIVE_THRESHOLD
 	 * times.  We're not steady until we've given them a chance
 	 * _after_ our first read.
+	 * The default threshold is bare minimum so as to limit the delay
+	 * during mounts. For global heartbeat, the threshold doubled for the
+	 * first region.
 	 */
-	atomic_set(&reg->hr_steady_iterations, O2HB_LIVE_THRESHOLD + 1);
+	live_threshold = O2HB_LIVE_THRESHOLD;
+	if (o2hb_global_heartbeat_active()) {
+		spin_lock(&o2hb_live_lock);
+		if (o2hb_pop_count(&o2hb_region_bitmap, O2NM_MAX_REGIONS) == 1)
+			live_threshold <<= 1;
+		spin_unlock(&o2hb_live_lock);
+	}
+	atomic_set(&reg->hr_steady_iterations, live_threshold + 1);
 
 	hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s",
 			      reg->hr_item.ci_name);
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 9fe5b8fd..8582e3f 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -2868,7 +2868,7 @@
 		bytes = blocks_wanted << sb->s_blocksize_bits;
 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
 	struct ocfs2_inode_info *oi = OCFS2_I(dir);
-	struct ocfs2_alloc_context *data_ac;
+	struct ocfs2_alloc_context *data_ac = NULL;
 	struct ocfs2_alloc_context *meta_ac = NULL;
 	struct buffer_head *dirdata_bh = NULL;
 	struct buffer_head *dx_root_bh = NULL;
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 7540a49..3b179d6 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -1614,7 +1614,8 @@
 	spin_unlock(&dlm->spinlock);
 
 	/* Support for global heartbeat and node info was added in 1.1 */
-	if (dlm_protocol.pv_major > 1 || dlm_protocol.pv_minor > 0) {
+	if (dlm->dlm_locking_proto.pv_major > 1 ||
+	    dlm->dlm_locking_proto.pv_minor > 0) {
 		status = dlm_send_nodeinfo(dlm, ctxt->yes_resp_map);
 		if (status) {
 			mlog_errno(status);
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index fede57e..84d1663 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2574,6 +2574,9 @@
 		res->state &= ~DLM_LOCK_RES_MIGRATING;
 		wake = 1;
 		spin_unlock(&res->spinlock);
+		if (dlm_is_host_down(ret))
+			dlm_wait_for_node_death(dlm, target,
+						DLM_NODE_DEATH_WAIT_MAX);
 		goto leave;
 	}
 
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 41565ae..89659d6 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1607,6 +1607,9 @@
 	range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
 
 	if (le32_to_cpu(rec->e_cpos) >= trunc_start) {
+		/*
+		 * remove an entire extent record.
+		 */
 		*trunc_cpos = le32_to_cpu(rec->e_cpos);
 		/*
 		 * Skip holes if any.
@@ -1617,7 +1620,16 @@
 		*blkno = le64_to_cpu(rec->e_blkno);
 		*trunc_end = le32_to_cpu(rec->e_cpos);
 	} else if (range > trunc_start) {
+		/*
+		 * remove a partial extent record, which means we're
+		 * removing the last extent record.
+		 */
 		*trunc_cpos = trunc_start;
+		/*
+		 * skip hole if any.
+		 */
+		if (range < *trunc_end)
+			*trunc_end = range;
 		*trunc_len = *trunc_end - trunc_start;
 		coff = trunc_start - le32_to_cpu(rec->e_cpos);
 		*blkno = le64_to_cpu(rec->e_blkno) +
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index b141a44..295d564 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -1260,6 +1260,9 @@
 {
 	struct ocfs2_journal *journal = osb->journal;
 
+	if (ocfs2_is_hard_readonly(osb))
+		return;
+
 	/* No need to queue up our truncate_log as regular cleanup will catch
 	 * that */
 	ocfs2_queue_recovery_completion(journal, osb->slot_num,
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index d545e97..8ed4d343 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -255,7 +255,11 @@
 				   struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);
-	return sprintf(buf, "%u\n", p->discard_alignment);
+	struct gendisk *disk = dev_to_disk(dev);
+
+	return sprintf(buf, "%u\n",
+			queue_limit_discard_alignment(&disk->queue->limits,
+							p->start_sect));
 }
 
 ssize_t part_stat_show(struct device *dev,
@@ -449,8 +453,6 @@
 	p->start_sect = start;
 	p->alignment_offset =
 		queue_limit_alignment_offset(&disk->queue->limits, start);
-	p->discard_alignment =
-		queue_limit_discard_alignment(&disk->queue->limits, start);
 	p->nr_sects = len;
 	p->partno = partno;
 	p->policy = get_disk_ro(disk);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2ad95fa..ae9091a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -257,7 +257,7 @@
 	unsigned char		misaligned;
 	unsigned char		discard_misaligned;
 	unsigned char		cluster;
-	signed char		discard_zeroes_data;
+	unsigned char		discard_zeroes_data;
 };
 
 struct request_queue
@@ -364,6 +364,8 @@
 	 * for flush operations
 	 */
 	unsigned int		flush_flags;
+	unsigned int		flush_not_queueable:1;
+	unsigned int		flush_queue_delayed:1;
 	unsigned int		flush_pending_idx:1;
 	unsigned int		flush_running_idx:1;
 	unsigned long		flush_pending_since;
@@ -843,6 +845,7 @@
 extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
+extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 
 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
@@ -1066,13 +1069,16 @@
 {
 	unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
 
+	if (!lim->max_discard_sectors)
+		return 0;
+
 	return (lim->discard_granularity + lim->discard_alignment - alignment)
 		& (lim->discard_granularity - 1);
 }
 
 static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
 {
-	if (q->limits.discard_zeroes_data == 1)
+	if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
 		return 1;
 
 	return 0;
@@ -1111,6 +1117,11 @@
 	return bdev->bd_block_size;
 }
 
+static inline bool queue_flush_queueable(struct request_queue *q)
+{
+	return !q->flush_not_queueable;
+}
+
 typedef struct {struct page *v;} Sector;
 
 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
diff --git a/include/linux/device.h b/include/linux/device.h
index ab8dfc0..d08399d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -442,7 +442,6 @@
 	struct dev_archdata	archdata;
 
 	struct device_node	*of_node; /* associated device tree node */
-	const struct of_device_id *of_match; /* matching of_device_id from driver */
 
 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
 
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index d764a42..b78956b 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -100,7 +100,6 @@
 	sector_t start_sect;
 	sector_t nr_sects;
 	sector_t alignment_offset;
-	unsigned int discard_alignment;
 	struct device __dev;
 	struct kobject *holder_dir;
 	int policy, partno;
@@ -127,6 +126,7 @@
 #define GENHD_FL_SUPPRESS_PARTITION_INFO	32
 #define GENHD_FL_EXT_DEVT			64 /* allow extended devt */
 #define GENHD_FL_NATIVE_CAPACITY		128
+#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	256
 
 enum {
 	DISK_EVENT_MEDIA_CHANGE			= 1 << 0, /* media changed */
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index 8bfe6c1..ae56384 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -21,8 +21,7 @@
 static inline int of_driver_match_device(struct device *dev,
 					 const struct device_driver *drv)
 {
-	dev->of_match = of_match_device(drv->of_match_table, dev);
-	return dev->of_match != NULL;
+	return of_match_device(drv->of_match_table, dev) != NULL;
 }
 
 extern struct platform_device *of_dev_get(struct platform_device *dev);
@@ -58,6 +57,11 @@
 
 static inline void of_device_node_put(struct device *dev) { }
 
+static inline const struct of_device_id *of_match_device(
+		const struct of_device_id *matches, const struct device *dev)
+{
+	return NULL;
+}
 #endif /* CONFIG_OF_DEVICE */
 
 #endif /* _LINUX_OF_DEVICE_H */