md: use list_for_each_entry macro directly

The rdev_for_each macro defined in <linux/raid/md_k.h> is identical to
list_for_each_entry_safe, from <linux/list.h>, it should be defined to
use list_for_each_entry_safe, instead of reinventing the wheel.

But some calls to each_entry_safe don't really need a safe version,
just a direct list_for_each_entry is enough, this could save a temp
variable (tmp) in every function that used rdev_for_each.

In this patch, most rdev_for_each loops are replaced by list_for_each_entry,
totally save many tmp vars; and only in the other situations that will call
list_del to delete an entry, the safe version is used.

Signed-off-by: Cheng Renquan <[e-mail]>
Signed-off-by: NeilBrown <[e-mail]>

drivers/md/bitmap.c

···
 	/* choose a good rdev and read the page from there */
 
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 	sector_t target;
 
 	if (!page)
···
 	if (!page)
 		return ERR_PTR(-ENOMEM);
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		if (! test_bit(In_sync, &rdev->flags)
 		    || test_bit(Faulty, &rdev->flags))
 			continue;

drivers/md/faulty.c

···
 static int run(mddev_t *mddev)
 {
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 	int i;
 
 	conf_t *conf = kmalloc(sizeof(*conf), GFP_KERNEL);
···
 	}
 	conf->nfaults = 0;
 
-	rdev_for_each(rdev, tmp, mddev)
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		conf->rdev = rdev;
 
 	mddev->array_sectors = mddev->size * 2;

drivers/md/linear.c

···
 	int i, nb_zone, cnt;
 	sector_t min_sectors;
 	sector_t curr_sector;
-	struct list_head *tmp;
 
 	conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(dev_info_t),
 			GFP_KERNEL);
···
 	cnt = 0;
 	conf->array_sectors = 0;
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		int j = rdev->raid_disk;
 		dev_info_t *disk = conf->disks + j;
 

drivers/md/md.c

···
 
 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
 {
-	mdk_rdev_t * rdev;
-	struct list_head *tmp;
+	mdk_rdev_t *rdev;
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		if (rdev->desc_nr == nr)
 			return rdev;
-	}
+
 	return NULL;
 }
 
 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
 {
-	struct list_head *tmp;
 	mdk_rdev_t *rdev;
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		if (rdev->bdev->bd_dev == dev)
 			return rdev;
-	}
+
 	return NULL;
 }
 
···
 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 {
 	mdp_super_t *sb;
-	struct list_head *tmp;
 	mdk_rdev_t *rdev2;
 	int next_spare = mddev->raid_disks;
 
···
 		sb->state |= (1<<MD_SB_BITMAP_PRESENT);
 
 	sb->disks[0].state = (1<<MD_DISK_REMOVED);
-	rdev_for_each(rdev2, tmp, mddev) {
+	list_for_each_entry(rdev2, &mddev->disks, same_set) {
 		mdp_disk_t *d;
 		int desc_nr;
 		if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
···
 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 {
 	struct mdp_superblock_1 *sb;
-	struct list_head *tmp;
 	mdk_rdev_t *rdev2;
 	int max_dev, i;
 	/* make rdev->sb match mddev and rdev data. */
···
 	}
 
 	max_dev = 0;
-	rdev_for_each(rdev2, tmp, mddev)
+	list_for_each_entry(rdev2, &mddev->disks, same_set)
 		if (rdev2->desc_nr+1 > max_dev)
 			max_dev = rdev2->desc_nr+1;
 
···
 	for (i=0; i<max_dev;i++)
 		sb->dev_roles[i] = cpu_to_le16(0xfffe);
 	
-	rdev_for_each(rdev2, tmp, mddev) {
+	list_for_each_entry(rdev2, &mddev->disks, same_set) {
 		i = rdev2->desc_nr;
 		if (test_bit(Faulty, &rdev2->flags))
 			sb->dev_roles[i] = cpu_to_le16(0xfffe);
···
 
 static void export_array(mddev_t *mddev)
 {
-	struct list_head *tmp;
-	mdk_rdev_t *rdev;
+	mdk_rdev_t *rdev, *tmp;
 
 	rdev_for_each(rdev, tmp, mddev) {
 		if (!rdev->mddev) {
···
 
 static void md_print_devices(void)
 {
-	struct list_head *tmp, *tmp2;
+	struct list_head *tmp;
 	mdk_rdev_t *rdev;
 	mddev_t *mddev;
 	char b[BDEVNAME_SIZE];
···
 			bitmap_print_sb(mddev->bitmap);
 		else
 			printk("%s: ", mdname(mddev));
-		rdev_for_each(rdev, tmp2, mddev)
+		list_for_each_entry(rdev, &mddev->disks, same_set)
 			printk("<%s>", bdevname(rdev->bdev,b));
 		printk("\n");
 
-		rdev_for_each(rdev, tmp2, mddev)
+		list_for_each_entry(rdev, &mddev->disks, same_set)
 			print_rdev(rdev);
 	}
 	printk("md:	**********************************\n");
···
 	 * with the rest of the array)
 	 */
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		if (rdev->sb_events == mddev->events ||
 		    (nospares &&
 		     rdev->raid_disk < 0 &&
···
 
 static void md_update_sb(mddev_t * mddev, int force_change)
 {
-	struct list_head *tmp;
 	mdk_rdev_t *rdev;
 	int sync_req;
 	int nospares = 0;
···
 		mdname(mddev),mddev->in_sync);
 
 	bitmap_update_sb(mddev->bitmap);
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		char b[BDEVNAME_SIZE];
 		dprintk(KERN_INFO "md: ");
 		if (rdev->sb_loaded != 1)
···
 		md_wakeup_thread(rdev->mddev->thread);
 	} else if (rdev->mddev->pers) {
 		mdk_rdev_t *rdev2;
-		struct list_head *tmp;
 		/* Activating a spare .. or possibly reactivating
 		 * if we every get bitmaps working here.
 		 */
···
 		if (rdev->mddev->pers->hot_add_disk == NULL)
 			return -EINVAL;
 
-		rdev_for_each(rdev2, tmp, rdev->mddev)
+		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
 			if (rdev2->raid_disk == slot)
 				return -EEXIST;
 
···
 		 */
 		mddev_t *mddev;
 		int overlap = 0;
-		struct list_head *tmp, *tmp2;
+		struct list_head *tmp;
 
 		mddev_unlock(my_mddev);
 		for_each_mddev(mddev, tmp) {
 			mdk_rdev_t *rdev2;
 
 			mddev_lock(mddev);
-			rdev_for_each(rdev2, tmp2, mddev)
+			list_for_each_entry(rdev2, &mddev->disks, same_set)
 				if (test_bit(AllReserved, &rdev2->flags) ||
 				    (rdev->bdev == rdev2->bdev &&
 				     rdev != rdev2 &&
···
 static void analyze_sbs(mddev_t * mddev)
 {
 	int i;
-	struct list_head *tmp;
-	mdk_rdev_t *rdev, *freshest;
+	mdk_rdev_t *rdev, *freshest, *tmp;
 	char b[BDEVNAME_SIZE];
 
 	freshest = NULL;
···
 {
 	int err;
 	int chunk_size;
-	struct list_head *tmp;
 	mdk_rdev_t *rdev;
 	struct gendisk *disk;
 	struct mdk_personality *pers;
···
 		}
 
 		/* devices must have minimum size of one chunk */
-		rdev_for_each(rdev, tmp, mddev) {
+		list_for_each_entry(rdev, &mddev->disks, same_set) {
 			if (test_bit(Faulty, &rdev->flags))
 				continue;
 			if (rdev->size < chunk_size / 1024) {
···
 	 * the only valid external interface is through the md
 	 * device.
 	 */
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		if (test_bit(Faulty, &rdev->flags))
 			continue;
 		sync_blockdev(rdev->bdev);
···
 		 */
 		char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
 		mdk_rdev_t *rdev2;
-		struct list_head *tmp2;
 		int warned = 0;
-		rdev_for_each(rdev, tmp, mddev) {
-			rdev_for_each(rdev2, tmp2, mddev) {
+
+		list_for_each_entry(rdev, &mddev->disks, same_set)
+			list_for_each_entry(rdev2, &mddev->disks, same_set) {
 				if (rdev < rdev2 &&
 				    rdev->bdev->bd_contains ==
 				    rdev2->bdev->bd_contains) {
···
 					warned = 1;
 				}
 			}
-		}
+
 		if (warned)
 			printk(KERN_WARNING
 			       "True protection against single-disk"
···
 	mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
 	mddev->in_sync = 1;
 
-	rdev_for_each(rdev, tmp, mddev)
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		if (rdev->raid_disk >= 0) {
 			char nm[20];
 			sprintf(nm, "rd%d", rdev->raid_disk);
···
 	 * it will remove the drives and not do the right thing
 	 */
 	if (mddev->degraded && !mddev->sync_thread) {
-		struct list_head *rtmp;
 		int spares = 0;
-		rdev_for_each(rdev, rtmp, mddev)
+		list_for_each_entry(rdev, &mddev->disks, same_set)
 			if (rdev->raid_disk >= 0 &&
 			    !test_bit(In_sync, &rdev->flags) &&
 			    !test_bit(Faulty, &rdev->flags))
···
 	 */
 	if (mode == 0) {
 		mdk_rdev_t *rdev;
-		struct list_head *tmp;
 
 		printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
···
 		}
 		mddev->bitmap_offset = 0;
 
-		rdev_for_each(rdev, tmp, mddev)
+		list_for_each_entry(rdev, &mddev->disks, same_set)
 			if (rdev->raid_disk >= 0) {
 				char nm[20];
 				sprintf(nm, "rd%d", rdev->raid_disk);
···
 static void autorun_array(mddev_t *mddev)
 {
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 	int err;
 
 	if (list_empty(&mddev->disks))
···
 
 	printk(KERN_INFO "md: running: ");
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		char b[BDEVNAME_SIZE];
 		printk("<%s>", bdevname(rdev->bdev,b));
 	}
···
  */
 static void autorun_devices(int part)
 {
-	struct list_head *tmp;
-	mdk_rdev_t *rdev0, *rdev;
+	mdk_rdev_t *rdev0, *rdev, *tmp;
 	mddev_t *mddev;
 	char b[BDEVNAME_SIZE];
 
···
 		printk(KERN_INFO "md: considering %s ...\n",
 			bdevname(rdev0->bdev,b));
 		INIT_LIST_HEAD(&candidates);
-		rdev_for_each_list(rdev, tmp, pending_raid_disks)
+		rdev_for_each_list(rdev, tmp, &pending_raid_disks)
 			if (super_90_load(rdev, rdev0, 0) >= 0) {
 				printk(KERN_INFO "md:  adding %s ...\n",
 					bdevname(rdev->bdev,b));
···
 		} else {
 			printk(KERN_INFO "md: created %s\n", mdname(mddev));
 			mddev->persistent = 1;
-			rdev_for_each_list(rdev, tmp, candidates) {
+			rdev_for_each_list(rdev, tmp, &candidates) {
 				list_del_init(&rdev->same_set);
 				if (bind_rdev_to_array(rdev, mddev))
 					export_rdev(rdev);
···
 		/* on success, candidates will be empty, on error
 		 * it won't...
 		 */
-		rdev_for_each_list(rdev, tmp, candidates) {
+		rdev_for_each_list(rdev, tmp, &candidates) {
 			list_del_init(&rdev->same_set);
 			export_rdev(rdev);
 		}
···
 	mdu_array_info_t info;
 	int nr,working,active,failed,spare;
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 
 	nr=working=active=failed=spare=0;
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		nr++;
 		if (test_bit(Faulty, &rdev->flags))
 			failed++;
···
 
 static int update_size(mddev_t *mddev, sector_t num_sectors)
 {
-	mdk_rdev_t * rdev;
+	mdk_rdev_t *rdev;
 	int rv;
-	struct list_head *tmp;
 	int fit = (num_sectors == 0);
 
 	if (mddev->pers->resize == NULL)
···
 		 * grow, and re-add.
 		 */
 		return -EBUSY;
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		sector_t avail;
 		avail = rdev->size * 2;
 
···
 {
 	int i = 0;
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 
 	seq_printf(seq, "unused devices: ");
 
-	rdev_for_each_list(rdev, tmp, pending_raid_disks) {
+	list_for_each_entry(rdev, &pending_raid_disks, same_set) {
 		char b[BDEVNAME_SIZE];
 		i++;
 		seq_printf(seq, "%s ",
···
 {
 	mddev_t *mddev = v;
 	sector_t size;
-	struct list_head *tmp2;
 	mdk_rdev_t *rdev;
 	struct mdstat_info *mi = seq->private;
 	struct bitmap *bitmap;
···
 		}
 
 		size = 0;
-		rdev_for_each(rdev, tmp2, mddev) {
+		list_for_each_entry(rdev, &mddev->disks, same_set) {
 			char b[BDEVNAME_SIZE];
 			seq_printf(seq, " %s[%d]",
 				bdevname(rdev->bdev,b), rdev->desc_nr);
···
 	struct list_head *tmp;
 	sector_t last_check;
 	int skipped = 0;
-	struct list_head *rtmp;
 	mdk_rdev_t *rdev;
 	char *desc;
 
···
 		/* recovery follows the physical size of devices */
 		max_sectors = mddev->size << 1;
 		j = MaxSector;
-		rdev_for_each(rdev, rtmp, mddev)
+		list_for_each_entry(rdev, &mddev->disks, same_set)
 			if (rdev->raid_disk >= 0 &&
 			    !test_bit(Faulty, &rdev->flags) &&
 			    !test_bit(In_sync, &rdev->flags) &&
···
 		} else {
 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
 				mddev->curr_resync = MaxSector;
-			rdev_for_each(rdev, rtmp, mddev)
+			list_for_each_entry(rdev, &mddev->disks, same_set)
 				if (rdev->raid_disk >= 0 &&
 				    !test_bit(Faulty, &rdev->flags) &&
 				    !test_bit(In_sync, &rdev->flags) &&
···
 static int remove_and_add_spares(mddev_t *mddev)
 {
 	mdk_rdev_t *rdev;
-	struct list_head *rtmp;
 	int spares = 0;
 
-	rdev_for_each(rdev, rtmp, mddev)
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		if (rdev->raid_disk >= 0 &&
 		    !test_bit(Blocked, &rdev->flags) &&
 		    (test_bit(Faulty, &rdev->flags) ||
···
 		}
 
 	if (mddev->degraded && ! mddev->ro) {
-		rdev_for_each(rdev, rtmp, mddev) {
+		list_for_each_entry(rdev, &mddev->disks, same_set) {
 			if (rdev->raid_disk >= 0 &&
 			    !test_bit(In_sync, &rdev->flags) &&
 			    !test_bit(Blocked, &rdev->flags))
···
 void md_check_recovery(mddev_t *mddev)
 {
 	mdk_rdev_t *rdev;
-	struct list_head *rtmp;
 
 
 	if (mddev->bitmap)
···
 		if (mddev->flags)
 			md_update_sb(mddev, 0);
 
-		rdev_for_each(rdev, rtmp, mddev)
+		list_for_each_entry(rdev, &mddev->disks, same_set)
 			if (test_and_clear_bit(StateChanged, &rdev->flags))
 				sysfs_notify_dirent(rdev->sysfs_state);
 
···
 			 * information must be scrapped
 			 */
 			if (!mddev->degraded)
-				rdev_for_each(rdev, rtmp, mddev)
+				list_for_each_entry(rdev, &mddev->disks, same_set)
 					rdev->saved_raid_disk = -1;
 
 			mddev->recovery = 0;

drivers/md/multipath.c

···
 	int disk_idx;
 	struct multipath_info *disk;
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 
 	if (mddev->level != LEVEL_MULTIPATH) {
 		printk("multipath: %s: raid level not set to multipath IO (%d)\n",
···
 	}
 
 	conf->working_disks = 0;
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		disk_idx = rdev->raid_disk;
 		if (disk_idx < 0 ||
 		    disk_idx >= mddev->raid_disks)

drivers/md/raid0.c

···
 	sector_t min_spacing;
 	raid0_conf_t *conf = mddev_to_conf(mddev);
 	mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev;
-	struct list_head *tmp1, *tmp2;
 	struct strip_zone *zone;
 	int cnt;
 	char b[BDEVNAME_SIZE];
···
 	 */
 	conf->nr_strip_zones = 0;
  
-	rdev_for_each(rdev1, tmp1, mddev) {
+	list_for_each_entry(rdev1, &mddev->disks, same_set) {
 		printk(KERN_INFO "raid0: looking at %s\n",
 			bdevname(rdev1->bdev,b));
 		c = 0;
-		rdev_for_each(rdev2, tmp2, mddev) {
+		list_for_each_entry(rdev2, &mddev->disks, same_set) {
 			printk(KERN_INFO "raid0:   comparing %s(%llu)",
 			       bdevname(rdev1->bdev,b),
 			       (unsigned long long)rdev1->size);
···
 	cnt = 0;
 	smallest = NULL;
 	zone->dev = conf->devlist;
-	rdev_for_each(rdev1, tmp1, mddev) {
+	list_for_each_entry(rdev1, &mddev->disks, same_set) {
 		int j = rdev1->raid_disk;
 
 		if (j < 0 || j >= mddev->raid_disks) {
···
 	s64 sectors;
 	raid0_conf_t *conf;
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 
 	if (mddev->chunk_size == 0) {
 		printk(KERN_ERR "md/raid0: non-zero chunk size required.\n");
···
 
 	/* calculate array device size */
 	mddev->array_sectors = 0;
-	rdev_for_each(rdev, tmp, mddev)
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		mddev->array_sectors += rdev->size * 2;
 
 	printk(KERN_INFO "raid0 : md_size is %llu sectors.\n",

drivers/md/raid1.c

···
 	int i, j, disk_idx;
 	mirror_info_t *disk;
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 
 	if (mddev->level != 1) {
 		printk("raid1: %s: raid level not set to mirroring (%d)\n",
···
 	spin_lock_init(&conf->device_lock);
 	mddev->queue->queue_lock = &conf->device_lock;
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		disk_idx = rdev->raid_disk;
 		if (disk_idx >= mddev->raid_disks
 		    || disk_idx < 0)

drivers/md/raid10.c

···
 	int i, disk_idx;
 	mirror_info_t *disk;
 	mdk_rdev_t *rdev;
-	struct list_head *tmp;
 	int nc, fc, fo;
 	sector_t stride, size;
 
···
 	spin_lock_init(&conf->device_lock);
 	mddev->queue->queue_lock = &conf->device_lock;
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		disk_idx = rdev->raid_disk;
 		if (disk_idx >= mddev->raid_disks
 		    || disk_idx < 0)

drivers/md/raid5.c

···
 	int raid_disk, memory;
 	mdk_rdev_t *rdev;
 	struct disk_info *disk;
-	struct list_head *tmp;
 	int working_disks = 0;
 
 	if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
···
 
 	pr_debug("raid5: run(%s) called.\n", mdname(mddev));
 
-	rdev_for_each(rdev, tmp, mddev) {
+	list_for_each_entry(rdev, &mddev->disks, same_set) {
 		raid_disk = rdev->raid_disk;
 		if (raid_disk >= conf->raid_disks
 		    || raid_disk < 0)
···
 {
 	raid5_conf_t *conf = mddev_to_conf(mddev);
 	mdk_rdev_t *rdev;
-	struct list_head *rtmp;
 	int spares = 0;
 	int added_devices = 0;
 	unsigned long flags;
···
 	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
 		return -EBUSY;
 
-	rdev_for_each(rdev, rtmp, mddev)
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		if (rdev->raid_disk < 0 &&
 		    !test_bit(Faulty, &rdev->flags))
 			spares++;
···
 	/* Add some new drives, as many as will fit.
 	 * We know there are enough to make the newly sized array work.
 	 */
-	rdev_for_each(rdev, rtmp, mddev)
+	list_for_each_entry(rdev, &mddev->disks, same_set)
 		if (rdev->raid_disk < 0 &&
 		    !test_bit(Faulty, &rdev->flags)) {
 			if (raid5_add_disk(mddev, rdev) == 0) {

include/linux/raid/md_k.h

···
  * iterates through some rdev ringlist. It's safe to remove the
  * current 'rdev'. Dont touch 'tmp' though.
  */
-#define rdev_for_each_list(rdev, tmp, list)				\
-									\
-	for ((tmp) = (list).next;					\
-		(rdev) = (list_entry((tmp), mdk_rdev_t, same_set)),	\
-			(tmp) = (tmp)->next, (tmp)->prev != &(list)	\
-		; )
+#define rdev_for_each_list(rdev, tmp, head)				\
+	list_for_each_entry_safe(rdev, tmp, head, same_set)
+
 /*
  * iterates through the 'same array disks' ringlist
  */
 #define rdev_for_each(rdev, tmp, mddev)				\
-	rdev_for_each_list(rdev, tmp, (mddev)->disks)
+	list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
 
 #define rdev_for_each_rcu(rdev, mddev)				\
 	list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)