X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=block%2Fgenhd.c;h=646e1d2507c70d2ba88824c3dd84d91874ecb192;hb=ef7822c2fbbb004e30e1fb6f79d6f8a1a1a144d7;hp=36b9f1bdd91f876ec944738cee8d1dea8bddc6ef;hpb=548b10eb2959c96cef6fc29fc96e0931eeb53bc5;p=linux-2.6-omap-h63xx.git

diff --git a/block/genhd.c b/block/genhd.c
index 36b9f1bdd91..646e1d2507c 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -52,14 +52,21 @@ static struct device_type disk_type;
  */
 struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
 {
-	struct hd_struct *part;
+	struct hd_struct *part = NULL;
+	struct disk_part_tbl *ptbl;
 
-	if (unlikely(partno < 0 || partno >= disk_max_parts(disk)))
+	if (unlikely(partno < 0))
 		return NULL;
+
 	rcu_read_lock();
-	part = rcu_dereference(disk->__part[partno]);
-	if (part)
-		get_device(part_to_dev(part));
+
+	ptbl = rcu_dereference(disk->part_tbl);
+	if (likely(partno < ptbl->len)) {
+		part = rcu_dereference(ptbl->part[partno]);
+		if (part)
+			get_device(part_to_dev(part));
+	}
+
 	rcu_read_unlock();
 
 	return part;
@@ -80,17 +87,24 @@ EXPORT_SYMBOL_GPL(disk_get_part);
 void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
 			  unsigned int flags)
 {
+	struct disk_part_tbl *ptbl;
+
+	rcu_read_lock();
+	ptbl = rcu_dereference(disk->part_tbl);
+
 	piter->disk = disk;
 	piter->part = NULL;
 
 	if (flags & DISK_PITER_REVERSE)
-		piter->idx = disk_max_parts(piter->disk) - 1;
+		piter->idx = ptbl->len - 1;
 	else if (flags & DISK_PITER_INCL_PART0)
 		piter->idx = 0;
 	else
 		piter->idx = 1;
 
 	piter->flags = flags;
+
+	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(disk_part_iter_init);
 
@@ -105,13 +119,16 @@ EXPORT_SYMBOL_GPL(disk_part_iter_init);
  */
 struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
 {
+	struct disk_part_tbl *ptbl;
 	int inc, end;
 
 	/* put the last partition */
 	disk_put_part(piter->part);
 	piter->part = NULL;
 
+	/* get part_tbl */
 	rcu_read_lock();
+	ptbl = rcu_dereference(piter->disk->part_tbl);
 
 	/* determine iteration parameters */
 	if (piter->flags & DISK_PITER_REVERSE) {
@@ -122,14 +139,14 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
 			end = 0;
 	} else {
 		inc = 1;
-		end = disk_max_parts(piter->disk);
+		end = ptbl->len;
 	}
 
 	/* iterate to the next partition */
 	for (; piter->idx != end; piter->idx += inc) {
 		struct hd_struct *part;
 
-		part = rcu_dereference(piter->disk->__part[piter->idx]);
+		part = rcu_dereference(ptbl->part[piter->idx]);
 		if (!part)
 			continue;
 		if (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects)
@@ -176,20 +193,23 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit);
  * while preemption is disabled.
  *
  * RETURNS:
- * Found partition on success, NULL if there's no matching partition.
+ * Found partition on success, part0 is returned if no partition matches
  */
 struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
 {
+	struct disk_part_tbl *ptbl;
 	int i;
 
-	for (i = 1; i < disk_max_parts(disk); i++) {
-		struct hd_struct *part = rcu_dereference(disk->__part[i]);
+	ptbl = rcu_dereference(disk->part_tbl);
+
+	for (i = 1; i < ptbl->len; i++) {
+		struct hd_struct *part = rcu_dereference(ptbl->part[i]);
 
 		if (part && part->start_sect <= sector &&
 		    sector < part->start_sect + part->nr_sects)
 			return part;
 	}
-	return NULL;
+	return &disk->part0;
 }
 EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
 
@@ -338,7 +358,6 @@ static int blk_mangle_minor(int minor)
 /**
  * blk_alloc_devt - allocate a dev_t for a partition
  * @part: partition to allocate dev_t for
- * @gfp_mask: memory allocation flag
  * @devt: out parameter for resulting dev_t
  *
  * Allocate a dev_t for block device.
@@ -458,14 +477,37 @@ static int exact_lock(dev_t devt, void *data)
  *
  * This function registers the partitioning information in @disk
  * with the kernel.
+ *
+ * FIXME: error handling
  */
 void add_disk(struct gendisk *disk)
 {
 	struct backing_dev_info *bdi;
+	dev_t devt;
 	int retval;
 
+	/* minors == 0 indicates to use ext devt from part0 and should
+	 * be accompanied with EXT_DEVT flag.  Make sure all
+	 * parameters make sense.
+	 */
+	WARN_ON(disk->minors && !(disk->major || disk->first_minor));
+	WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
+
 	disk->flags |= GENHD_FL_UP;
-	disk_to_dev(disk)->devt = MKDEV(disk->major, disk->first_minor);
+
+	retval = blk_alloc_devt(&disk->part0, &devt);
+	if (retval) {
+		WARN_ON(1);
+		return;
+	}
+	disk_to_dev(disk)->devt = devt;
+
+	/* ->major and ->first_minor aren't supposed to be
+	 * dereferenced from here on, but set them just in case.
+	 */
+	disk->major = MAJOR(devt);
+	disk->first_minor = MINOR(devt);
+
 	blk_register_region(disk_devt(disk), disk->minors, NULL,
 			    exact_match, exact_lock, disk);
 	register_disk(disk);
@@ -492,7 +534,7 @@ void unlink_gendisk(struct gendisk *disk)
 /**
  * get_gendisk - get partitioning information for a given device
  * @devt: device to get partitioning information for
- * @part: returned partition index
+ * @partno: returned partition index
  *
  * This function gets the structure containing partitioning
  * information for the given device @devt.
@@ -535,13 +577,13 @@ struct gendisk *get_gendisk(dev_t devt, int *partno)
  * RETURNS:
  * Resulting block_device on success, NULL on failure.
  */
-extern struct block_device *bdget_disk(struct gendisk *disk, int partno)
+struct block_device *bdget_disk(struct gendisk *disk, int partno)
 {
 	struct hd_struct *part;
 	struct block_device *bdev = NULL;
 
 	part = disk_get_part(disk, partno);
-	if (part && (part->nr_sects || partno == 0))
+	if (part)
 		bdev = bdget(part_devt(part));
 	disk_put_part(part);
 
@@ -580,24 +622,24 @@ void __init printk_all_partitions(void)
 		 * numbers in hex - the same format as the root=
 		 * option takes.
 		 */
-		printk("%s %10llu %s",
-		       bdevt_str(disk_devt(disk), devt_buf),
-		       (unsigned long long)get_capacity(disk) >> 1,
-		       disk_name(disk, 0, name_buf));
-		if (disk->driverfs_dev != NULL &&
-		    disk->driverfs_dev->driver != NULL)
-			printk(" driver: %s\n",
-			       disk->driverfs_dev->driver->name);
-		else
-			printk(" (driver?)\n");
+		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+		while ((part = disk_part_iter_next(&piter))) {
+			bool is_part0 = part == &disk->part0;
 
-		/* now show the partitions */
-		disk_part_iter_init(&piter, disk, 0);
-		while ((part = disk_part_iter_next(&piter)))
-			printk("  %s %10llu %s\n",
+			printk("%s%s %10llu %s", is_part0 ? "" : "  ",
 			       bdevt_str(part_devt(part), devt_buf),
 			       (unsigned long long)part->nr_sects >> 1,
 			       disk_name(disk, part->partno, name_buf));
+			if (is_part0) {
+				if (disk->driverfs_dev != NULL &&
+				    disk->driverfs_dev->driver != NULL)
+					printk(" driver: %s\n",
+					      disk->driverfs_dev->driver->name);
+				else
+					printk(" (driver?)\n");
+			} else
+				printk("\n");
+		}
 		disk_part_iter_exit(&piter);
 	}
 	class_dev_iter_exit(&iter);
@@ -611,7 +653,7 @@ static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
 	struct class_dev_iter *iter;
 	struct device *dev;
 
-	iter = kmalloc(GFP_KERNEL, sizeof(*iter));
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
 	if (!iter)
 		return ERR_PTR(-ENOMEM);
 
@@ -654,7 +696,7 @@ static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
 	static void *p;
 
 	p = disk_seqf_start(seqf, pos);
-	if (!IS_ERR(p) && p)
+	if (!IS_ERR(p) && p && !*pos)
 		seq_puts(seqf, "major minor  #blocks  name\n\n");
 	return p;
 }
@@ -674,12 +716,7 @@ static int show_partition(struct seq_file *seqf, void *v)
 		return 0;
 
 	/* show the full disk and all non-0 size partitions of it */
-	seq_printf(seqf, "%4d  %7d %10llu %s\n",
-		MAJOR(disk_devt(sgp)), MINOR(disk_devt(sgp)),
-		(unsigned long long)get_capacity(sgp) >> 1,
-		disk_name(sgp, 0, buf));
-
-	disk_part_iter_init(&piter, sgp, 0);
+	disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
 	while ((part = disk_part_iter_next(&piter)))
 		seq_printf(seqf, "%4d  %7d %10llu %s\n",
 			   MAJOR(part_devt(part)), MINOR(part_devt(part)),
@@ -757,15 +794,7 @@ static ssize_t disk_ro_show(struct device *dev,
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
-	return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
-}
-
-static ssize_t disk_size_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-
-	return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
+	return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
 }
 
 static ssize_t disk_capability_show(struct device *dev,
@@ -776,71 +805,21 @@ static ssize_t disk_capability_show(struct device *dev,
 	return sprintf(buf, "%x\n", disk->flags);
 }
 
-static ssize_t disk_stat_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-	int cpu;
-
-	cpu = disk_stat_lock();
-	disk_round_stats(cpu, disk);
-	disk_stat_unlock();
-	return sprintf(buf,
-		"%8lu %8lu %8llu %8u "
-		"%8lu %8lu %8llu %8u "
-		"%8u %8u %8u"
-		"\n",
-		disk_stat_read(disk, ios[READ]),
-		disk_stat_read(disk, merges[READ]),
-		(unsigned long long)disk_stat_read(disk, sectors[READ]),
-		jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
-		disk_stat_read(disk, ios[WRITE]),
-		disk_stat_read(disk, merges[WRITE]),
-		(unsigned long long)disk_stat_read(disk, sectors[WRITE]),
-		jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
-		disk->in_flight,
-		jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
-		jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
-}
-
-#ifdef CONFIG_FAIL_MAKE_REQUEST
-static ssize_t disk_fail_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-
-	return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
-}
-
-static ssize_t disk_fail_store(struct device *dev,
-			       struct device_attribute *attr,
-			       const char *buf, size_t count)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-	int i;
-
-	if (count > 0 && sscanf(buf, "%d", &i) > 0) {
-		if (i == 0)
-			disk->flags &= ~GENHD_FL_FAIL;
-		else
-			disk->flags |= GENHD_FL_FAIL;
-	}
-
-	return count;
-}
-
-#endif
-
 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
-static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
+static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
-static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
+static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 static struct device_attribute dev_attr_fail =
-	__ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
+	__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
+#endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+static struct device_attribute dev_attr_fail_timeout =
+	__ATTR(io-timeout-fail,  S_IRUGO|S_IWUSR, part_timeout_show,
+		part_timeout_store);
 #endif
 
 static struct attribute *disk_attrs[] = {
@@ -853,6 +832,9 @@ static struct attribute *disk_attrs[] = {
 	&dev_attr_stat.attr,
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 	&dev_attr_fail.attr,
+#endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+	&dev_attr_fail_timeout.attr,
 #endif
 	NULL
 };
@@ -866,13 +848,87 @@ static struct attribute_group *disk_attr_groups[] = {
 	NULL
 };
 
+static void disk_free_ptbl_rcu_cb(struct rcu_head *head)
+{
+	struct disk_part_tbl *ptbl =
+		container_of(head, struct disk_part_tbl, rcu_head);
+
+	kfree(ptbl);
+}
+
+/**
+ * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
+ * @disk: disk to replace part_tbl for
+ * @new_ptbl: new part_tbl to install
+ *
+ * Replace disk->part_tbl with @new_ptbl in RCU-safe way.  The
+ * original ptbl is freed using RCU callback.
+ *
+ * LOCKING:
+ * Matching bd_mutx locked.
+ */
+static void disk_replace_part_tbl(struct gendisk *disk,
+				  struct disk_part_tbl *new_ptbl)
+{
+	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+
+	rcu_assign_pointer(disk->part_tbl, new_ptbl);
+	if (old_ptbl)
+		call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb);
+}
+
+/**
+ * disk_expand_part_tbl - expand disk->part_tbl
+ * @disk: disk to expand part_tbl for
+ * @partno: expand such that this partno can fit in
+ *
+ * Expand disk->part_tbl such that @partno can fit in.  disk->part_tbl
+ * uses RCU to allow unlocked dereferencing for stats and other stuff.
+ *
+ * LOCKING:
+ * Matching bd_mutex locked, might sleep.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int disk_expand_part_tbl(struct gendisk *disk, int partno)
+{
+	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+	struct disk_part_tbl *new_ptbl;
+	int len = old_ptbl ? old_ptbl->len : 0;
+	int target = partno + 1;
+	size_t size;
+	int i;
+
+	/* disk_max_parts() is zero during initialization, ignore if so */
+	if (disk_max_parts(disk) && target > disk_max_parts(disk))
+		return -EINVAL;
+
+	if (target <= len)
+		return 0;
+
+	size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
+	new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
+	if (!new_ptbl)
+		return -ENOMEM;
+
+	INIT_RCU_HEAD(&new_ptbl->rcu_head);
+	new_ptbl->len = target;
+
+	for (i = 0; i < len; i++)
+		rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
+
+	disk_replace_part_tbl(disk, new_ptbl);
+	return 0;
+}
+
 static void disk_release(struct device *dev)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
 	kfree(disk->random);
-	kfree(disk->__part);
-	free_disk_stats(disk);
+	disk_replace_part_tbl(disk, NULL);
+	free_part_stats(&disk->part0);
 	kfree(disk);
 }
 struct class block_class = {
@@ -909,28 +965,11 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 				"\n\n");
 	*/
  
-	cpu = disk_stat_lock();
-	disk_round_stats(cpu, gp);
-	disk_stat_unlock();
-	seq_printf(seqf, "%4d %7d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
-		MAJOR(disk_devt(gp)), MINOR(disk_devt(gp)),
-		disk_name(gp, 0, buf),
-		disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
-		(unsigned long long)disk_stat_read(gp, sectors[0]),
-		jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
-		disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
-		(unsigned long long)disk_stat_read(gp, sectors[1]),
-		jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
-		gp->in_flight,
-		jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
-		jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
-
-	/* now show all non-0 size partitions of it */
-	disk_part_iter_init(&piter, gp, 0);
+	disk_part_iter_init(&piter, gp, DISK_PITER_INCL_PART0);
 	while ((hd = disk_part_iter_next(&piter))) {
-		cpu = disk_stat_lock();
+		cpu = part_stat_lock();
 		part_round_stats(cpu, hd);
-		disk_stat_unlock();
+		part_stat_unlock();
 		seq_printf(seqf, "%4d %7d %s %lu %lu %llu "
 			   "%u %lu %lu %llu %u %u %u %u\n",
 			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
@@ -999,7 +1038,7 @@ dev_t blk_lookup_devt(const char *name, int partno)
 			continue;
 
 		part = disk_get_part(disk, partno);
-		if (part && (part->nr_sects || partno == 0)) {
+		if (part) {
 			devt = part_devt(part);
 			disk_put_part(part);
 			break;
@@ -1015,57 +1054,38 @@ struct gendisk *alloc_disk(int minors)
 {
 	return alloc_disk_node(minors, -1);
 }
+EXPORT_SYMBOL(alloc_disk);
 
 struct gendisk *alloc_disk_node(int minors, int node_id)
-{
-	return alloc_disk_ext_node(minors, 0, node_id);
-}
-
-struct gendisk *alloc_disk_ext(int minors, int ext_minors)
-{
-	return alloc_disk_ext_node(minors, ext_minors, -1);
-}
-
-struct gendisk *alloc_disk_ext_node(int minors, int ext_minors, int node_id)
 {
 	struct gendisk *disk;
 
 	disk = kmalloc_node(sizeof(struct gendisk),
 				GFP_KERNEL | __GFP_ZERO, node_id);
 	if (disk) {
-		int tot_minors = minors + ext_minors;
-		int size = tot_minors * sizeof(struct hd_struct *);
-
-		if (!init_disk_stats(disk)) {
+		if (!init_part_stats(&disk->part0)) {
 			kfree(disk);
 			return NULL;
 		}
-
-		disk->__part = kmalloc_node(size, GFP_KERNEL | __GFP_ZERO,
-					    node_id);
-		if (!disk->__part) {
-			free_disk_stats(disk);
+		if (disk_expand_part_tbl(disk, 0)) {
+			free_part_stats(&disk->part0);
 			kfree(disk);
 			return NULL;
 		}
-		disk->__part[0] = &disk->part0;
+		disk->part_tbl->part[0] = &disk->part0;
 
 		disk->minors = minors;
-		disk->ext_minors = ext_minors;
 		rand_initialize_disk(disk);
 		disk_to_dev(disk)->class = &block_class;
 		disk_to_dev(disk)->type = &disk_type;
 		device_initialize(disk_to_dev(disk));
 		INIT_WORK(&disk->async_notify,
 			media_change_notify_thread);
+		disk->node_id = node_id;
 	}
 	return disk;
 }
-
-EXPORT_SYMBOL(alloc_disk);
 EXPORT_SYMBOL(alloc_disk_node);
-EXPORT_SYMBOL(alloc_disk_ext);
-EXPORT_SYMBOL(alloc_disk_ext_node);
 
 struct kobject *get_disk(struct gendisk *disk)
 {
@@ -1098,10 +1118,7 @@ EXPORT_SYMBOL(put_disk);
 
 void set_device_ro(struct block_device *bdev, int flag)
 {
-	if (bdev->bd_contains != bdev)
-		bdev->bd_part->policy = flag;
-	else
-		bdev->bd_disk->policy = flag;
+	bdev->bd_part->policy = flag;
 }
 
 EXPORT_SYMBOL(set_device_ro);
@@ -1111,8 +1128,8 @@ void set_disk_ro(struct gendisk *disk, int flag)
 	struct disk_part_iter piter;
 	struct hd_struct *part;
 
-	disk->policy = flag;
-	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
+	disk_part_iter_init(&piter, disk,
+			    DISK_PITER_INCL_EMPTY | DISK_PITER_INCL_PART0);
 	while ((part = disk_part_iter_next(&piter)))
 		part->policy = flag;
 	disk_part_iter_exit(&piter);
@@ -1124,10 +1141,7 @@ int bdev_read_only(struct block_device *bdev)
 {
 	if (!bdev)
 		return 0;
-	else if (bdev->bd_contains != bdev)
-		return bdev->bd_part->policy;
-	else
-		return bdev->bd_disk->policy;
+	return bdev->bd_part->policy;
 }
 
 EXPORT_SYMBOL(bdev_read_only);