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 <crquan@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 43 insertions, 64 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index ee759b193e9a..58be665bb46b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -307,25 +307,23 @@ static inline void mddev_unlock(mddev_t * mddev)
 
 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;
 }
 
@@ -861,7 +859,6 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 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;
 
@@ -933,7 +930,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
                 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)
@@ -1259,7 +1256,6 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 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. */
@@ -1307,7 +1303,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
         }
 
         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;
 
@@ -1316,7 +1312,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
         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);
@@ -1571,8 +1567,7 @@ static void kick_rdev_from_array(mdk_rdev_t * rdev)
 
 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) {
@@ -1643,7 +1638,7 @@ static void print_rdev(mdk_rdev_t *rdev)
 
 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];
@@ -1658,11 +1653,11 @@ static void md_print_devices(void)
                         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");
@@ -1679,9 +1674,8 @@ static void sync_sbs(mddev_t * mddev, int nospares)
          * 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 &&
@@ -1699,7 +1693,6 @@ static void sync_sbs(mddev_t * mddev, int nospares)
 
 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;
@@ -1790,7 +1783,7 @@ repeat:
                 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)
@@ -1999,7 +1992,6 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 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.
                  */
@@ -2010,7 +2002,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 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;
 
@@ -2125,14 +2117,14 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                  */
                 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 &&
@@ -2328,8 +2320,7 @@ abort_free:
 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;
@@ -3501,7 +3492,6 @@ static int do_md_run(mddev_t * mddev)
 {
         int err;
         int chunk_size;
-        struct list_head *tmp;
         mdk_rdev_t *rdev;
         struct gendisk *disk;
         struct mdk_personality *pers;
@@ -3540,7 +3530,7 @@ static int do_md_run(mddev_t * mddev)
                 }
 
                 /* 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) {
@@ -3565,7 +3555,7 @@ static int do_md_run(mddev_t * mddev)
          * 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);
@@ -3630,10 +3620,10 @@ static int do_md_run(mddev_t * mddev)
                  */
                 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) {
@@ -3647,7 +3637,7 @@ static int do_md_run(mddev_t * mddev)
                                         warned = 1;
                                 }
                         }
-                }
+
                 if (warned)
                         printk(KERN_WARNING
                                "True protection against single-disk"
@@ -3695,7 +3685,7 @@ static int do_md_run(mddev_t * mddev)
         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);
@@ -3726,9 +3716,8 @@ static int do_md_run(mddev_t * mddev)
          * 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))
@@ -3888,7 +3877,6 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
          */
         if (mode == 0) {
                 mdk_rdev_t *rdev;
-                struct list_head *tmp;
 
                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
@@ -3900,7 +3888,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                 }
                 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);
@@ -3961,7 +3949,6 @@ out:
 static void autorun_array(mddev_t *mddev)
 {
         mdk_rdev_t *rdev;
-        struct list_head *tmp;
         int err;
 
         if (list_empty(&mddev->disks))
@@ -3969,7 +3956,7 @@ static void autorun_array(mddev_t *mddev)
 
         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));
         }
@@ -3996,8 +3983,7 @@ static void autorun_array(mddev_t *mddev)
  */
 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];
 
@@ -4012,7 +3998,7 @@ static void autorun_devices(int part)
                 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));
@@ -4058,7 +4044,7 @@ static void autorun_devices(int part)
                 } 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);
@@ -4069,7 +4055,7 @@ static void autorun_devices(int part)
                 /* 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);
                 }
@@ -4098,10 +4084,9 @@ static int get_array_info(mddev_t * mddev, void __user * arg)
         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++;
@@ -4619,9 +4604,8 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
 
 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)
@@ -4643,7 +4627,7 @@ static int update_size(mddev_t *mddev, sector_t num_sectors)
                  * 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;
 
@@ -5192,11 +5176,10 @@ static void status_unused(struct seq_file *seq)
 {
         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 ",
@@ -5355,7 +5338,6 @@ static int md_seq_show(struct seq_file *seq, void *v)
 {
         mddev_t *mddev = v;
         sector_t size;
-        struct list_head *tmp2;
         mdk_rdev_t *rdev;
         struct mdstat_info *mi = seq->private;
         struct bitmap *bitmap;
@@ -5392,7 +5374,7 @@ static int md_seq_show(struct seq_file *seq, void *v)
                 }
 
                 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);
@@ -5699,7 +5681,6 @@ void md_do_sync(mddev_t *mddev)
         struct list_head *tmp;
         sector_t last_check;
         int skipped = 0;
-        struct list_head *rtmp;
         mdk_rdev_t *rdev;
         char *desc;
 
@@ -5804,7 +5785,7 @@ void md_do_sync(mddev_t *mddev)
                 /* 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) &&
@@ -5954,7 +5935,7 @@ void md_do_sync(mddev_t *mddev)
                 } 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) &&
@@ -5990,10 +5971,9 @@ EXPORT_SYMBOL_GPL(md_do_sync);
 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) ||
@@ -6009,7 +5989,7 @@ static int remove_and_add_spares(mddev_t *mddev)
                 }
 
         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))
@@ -6061,7 +6041,6 @@ static int remove_and_add_spares(mddev_t *mddev)
 void md_check_recovery(mddev_t *mddev)
 {
         mdk_rdev_t *rdev;
-        struct list_head *rtmp;
 
 
         if (mddev->bitmap)
@@ -6125,7 +6104,7 @@ void md_check_recovery(mddev_t *mddev)
                 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);
 
@@ -6154,7 +6133,7 @@ void md_check_recovery(mddev_t *mddev)
                          * 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;