Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt...
[safe/jmp/linux-2.6] / drivers / md / raid5.c
index 40e9396..a5ba080 100644 (file)
  * miss any bits.
  */
 
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/highmem.h>
-#include <linux/bitops.h>
 #include <linux/kthread.h>
-#include <asm/atomic.h>
 #include "raid6.h"
 
 #include <linux/raid/bitmap.h>
 const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
 #endif
 
+/*
+ * We maintain a biased count of active stripes in the bottom 16 bits of
+ * bi_phys_segments, and a count of processed stripes in the upper 16 bits
+ */
+static inline int raid5_bi_phys_segments(struct bio *bio)
+{
+       return bio->bi_phys_segments & 0xffff;
+}
+
+static inline int raid5_bi_hw_segments(struct bio *bio)
+{
+       return (bio->bi_phys_segments >> 16) & 0xffff;
+}
+
+static inline int raid5_dec_bi_phys_segments(struct bio *bio)
+{
+       --bio->bi_phys_segments;
+       return raid5_bi_phys_segments(bio);
+}
+
+static inline int raid5_dec_bi_hw_segments(struct bio *bio)
+{
+       unsigned short val = raid5_bi_hw_segments(bio);
+
+       --val;
+       bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
+       return val;
+}
+
+static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
+{
+       bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
+}
+
 static inline int raid6_next_disk(int disk, int raid_disks)
 {
        disk++;
@@ -241,7 +270,7 @@ static int grow_buffers(struct stripe_head *sh, int num)
        return 0;
 }
 
-static void raid5_build_block (struct stripe_head *sh, int i);
+static void raid5_build_block(struct stripe_head *sh, int i);
 
 static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks)
 {
@@ -507,7 +536,7 @@ static void ops_complete_biofill(void *stripe_head_ref)
                        while (rbi && rbi->bi_sector <
                                dev->sector + STRIPE_SECTORS) {
                                rbi2 = r5_next_bio(rbi, dev->sector);
-                               if (--rbi->bi_phys_segments == 0) {
+                               if (!raid5_dec_bi_phys_segments(rbi)) {
                                        rbi->bi_next = return_bi;
                                        return_bi = rbi;
                                }
@@ -1117,7 +1146,7 @@ static void raid5_end_read_request(struct bio * bi, int error)
        release_stripe(sh);
 }
 
-static void raid5_end_write_request (struct bio *bi, int error)
+static void raid5_end_write_request(struct bio *bi, int error)
 {
        struct stripe_head *sh = bi->bi_private;
        raid5_conf_t *conf = sh->raid_conf;
@@ -1149,7 +1178,7 @@ static void raid5_end_write_request (struct bio *bi, int error)
 
 static sector_t compute_blocknr(struct stripe_head *sh, int i);
        
-static void raid5_build_block (struct stripe_head *sh, int i)
+static void raid5_build_block(struct stripe_head *sh, int i)
 {
        struct r5dev *dev = &sh->dev[i];
 
@@ -1187,10 +1216,10 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
                        set_bit(MD_RECOVERY_INTR, &mddev->recovery);
                }
                set_bit(Faulty, &rdev->flags);
-               printk (KERN_ALERT
-                       "raid5: Disk failure on %s, disabling device.\n"
-                       "raid5: Operation continuing on %d devices.\n",
-                       bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
+               printk(KERN_ALERT
+                      "raid5: Disk failure on %s, disabling device.\n"
+                      "raid5: Operation continuing on %d devices.\n",
+                      bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
        }
 }
 
@@ -1286,8 +1315,8 @@ static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
                        *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
                        break;
                default:
-                       printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
-                               conf->algorithm);
+                       printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
+                              conf->algorithm);
                }
                break;
        }
@@ -1362,8 +1391,8 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
                        }
                        break;
                default:
-                       printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
-                               conf->algorithm);
+                       printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
+                              conf->algorithm);
                }
                break;
        }
@@ -1371,7 +1400,7 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
        chunk_number = stripe * data_disks + i;
        r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
 
-       check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
+       check = raid5_compute_sector(r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
        if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
                printk(KERN_ERR "compute_blocknr: map not correct\n");
                return 0;
@@ -1725,7 +1754,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
        if (*bip)
                bi->bi_next = *bip;
        *bip = bi;
-       bi->bi_phys_segments ++;
+       bi->bi_phys_segments++;
        spin_unlock_irq(&conf->device_lock);
        spin_unlock(&sh->lock);
 
@@ -1819,7 +1848,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
                        sh->dev[i].sector + STRIPE_SECTORS) {
                        struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
                        clear_bit(BIO_UPTODATE, &bi->bi_flags);
-                       if (--bi->bi_phys_segments == 0) {
+                       if (!raid5_dec_bi_phys_segments(bi)) {
                                md_write_end(conf->mddev);
                                bi->bi_next = *return_bi;
                                *return_bi = bi;
@@ -1834,7 +1863,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
                       sh->dev[i].sector + STRIPE_SECTORS) {
                        struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
                        clear_bit(BIO_UPTODATE, &bi->bi_flags);
-                       if (--bi->bi_phys_segments == 0) {
+                       if (!raid5_dec_bi_phys_segments(bi)) {
                                md_write_end(conf->mddev);
                                bi->bi_next = *return_bi;
                                *return_bi = bi;
@@ -1858,7 +1887,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
                                struct bio *nextbi =
                                        r5_next_bio(bi, sh->dev[i].sector);
                                clear_bit(BIO_UPTODATE, &bi->bi_flags);
-                               if (--bi->bi_phys_segments == 0) {
+                               if (!raid5_dec_bi_phys_segments(bi)) {
                                        bi->bi_next = *return_bi;
                                        *return_bi = bi;
                                }
@@ -2033,7 +2062,7 @@ static void handle_stripe_clean_event(raid5_conf_t *conf,
                                while (wbi && wbi->bi_sector <
                                        dev->sector + STRIPE_SECTORS) {
                                        wbi2 = r5_next_bio(wbi, dev->sector);
-                                       if (--wbi->bi_phys_segments == 0) {
+                                       if (!raid5_dec_bi_phys_segments(wbi)) {
                                                md_write_end(conf->mddev);
                                                wbi->bi_next = *return_bi;
                                                *return_bi = wbi;
@@ -2568,10 +2597,10 @@ static bool handle_stripe5(struct stripe_head *sh)
                if (dev->written)
                        s.written++;
                rdev = rcu_dereference(conf->disks[i].rdev);
-               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+               if (blocked_rdev == NULL &&
+                   rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
                        blocked_rdev = rdev;
                        atomic_inc(&rdev->nr_pending);
-                       break;
                }
                if (!rdev || !test_bit(In_sync, &rdev->flags)) {
                        /* The ReadError flag will just be confusing now */
@@ -2588,8 +2617,14 @@ static bool handle_stripe5(struct stripe_head *sh)
        rcu_read_unlock();
 
        if (unlikely(blocked_rdev)) {
-               set_bit(STRIPE_HANDLE, &sh->state);
-               goto unlock;
+               if (s.syncing || s.expanding || s.expanded ||
+                   s.to_write || s.written) {
+                       set_bit(STRIPE_HANDLE, &sh->state);
+                       goto unlock;
+               }
+               /* There is nothing for the blocked_rdev to block */
+               rdev_dec_pending(blocked_rdev, conf->mddev);
+               blocked_rdev = NULL;
        }
 
        if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
@@ -2808,7 +2843,7 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
                                copy_data(0, rbi, dev->page, dev->sector);
                                rbi2 = r5_next_bio(rbi, dev->sector);
                                spin_lock_irq(&conf->device_lock);
-                               if (--rbi->bi_phys_segments == 0) {
+                               if (!raid5_dec_bi_phys_segments(rbi)) {
                                        rbi->bi_next = return_bi;
                                        return_bi = rbi;
                                }
@@ -2832,10 +2867,10 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
                if (dev->written)
                        s.written++;
                rdev = rcu_dereference(conf->disks[i].rdev);
-               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+               if (blocked_rdev == NULL &&
+                   rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
                        blocked_rdev = rdev;
                        atomic_inc(&rdev->nr_pending);
-                       break;
                }
                if (!rdev || !test_bit(In_sync, &rdev->flags)) {
                        /* The ReadError flag will just be confusing now */
@@ -2853,9 +2888,16 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
        rcu_read_unlock();
 
        if (unlikely(blocked_rdev)) {
-               set_bit(STRIPE_HANDLE, &sh->state);
-               goto unlock;
+               if (s.syncing || s.expanding || s.expanded ||
+                   s.to_write || s.written) {
+                       set_bit(STRIPE_HANDLE, &sh->state);
+                       goto unlock;
+               }
+               /* There is nothing for the blocked_rdev to block */
+               rdev_dec_pending(blocked_rdev, conf->mddev);
+               blocked_rdev = NULL;
        }
+
        pr_debug("locked=%d uptodate=%d to_read=%d"
               " to_write=%d failed=%d failed_num=%d,%d\n",
               s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
@@ -3142,8 +3184,11 @@ static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
        if(bi) {
                conf->retry_read_aligned_list = bi->bi_next;
                bi->bi_next = NULL;
+               /*
+                * this sets the active strip count to 1 and the processed
+                * strip count to zero (upper 8 bits)
+                */
                bi->bi_phys_segments = 1; /* biased count of active stripes */
-               bi->bi_hw_segments = 0; /* count of processed stripes */
        }
 
        return bi;
@@ -3193,8 +3238,7 @@ static int bio_fits_rdev(struct bio *bi)
        if ((bi->bi_size>>9) > q->max_sectors)
                return 0;
        blk_recount_segments(q, bi);
-       if (bi->bi_phys_segments > q->max_phys_segments ||
-           bi->bi_hw_segments > q->max_hw_segments)
+       if (bi->bi_phys_segments > q->max_phys_segments)
                return 0;
 
        if (q->merge_bvec_fn)
@@ -3338,7 +3382,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
        sector_t logical_sector, last_sector;
        struct stripe_head *sh;
        const int rw = bio_data_dir(bi);
-       int remaining;
+       int cpu, remaining;
 
        if (unlikely(bio_barrier(bi))) {
                bio_endio(bi, -EOPNOTSUPP);
@@ -3347,8 +3391,11 @@ static int make_request(struct request_queue *q, struct bio * bi)
 
        md_write_start(mddev, bi);
 
-       disk_stat_inc(mddev->gendisk, ios[rw]);
-       disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
+       cpu = part_stat_lock();
+       part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+       part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+                     bio_sectors(bi));
+       part_stat_unlock();
 
        if (rw == READ &&
             mddev->reshape_position == MaxSector &&
@@ -3455,7 +3502,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
                        
        }
        spin_lock_irq(&conf->device_lock);
-       remaining = --bi->bi_phys_segments;
+       remaining = raid5_dec_bi_phys_segments(bi);
        spin_unlock_irq(&conf->device_lock);
        if (remaining == 0) {
 
@@ -3739,7 +3786,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
                     sector += STRIPE_SECTORS,
                     scnt++) {
 
-               if (scnt < raid_bio->bi_hw_segments)
+               if (scnt < raid5_bi_hw_segments(raid_bio))
                        /* already done this stripe */
                        continue;
 
@@ -3747,7 +3794,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
 
                if (!sh) {
                        /* failed to get a stripe - must wait */
-                       raid_bio->bi_hw_segments = scnt;
+                       raid5_set_bi_hw_segments(raid_bio, scnt);
                        conf->retry_read_aligned = raid_bio;
                        return handled;
                }
@@ -3755,7 +3802,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
                set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
                if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
                        release_stripe(sh);
-                       raid_bio->bi_hw_segments = scnt;
+                       raid5_set_bi_hw_segments(raid_bio, scnt);
                        conf->retry_read_aligned = raid_bio;
                        return handled;
                }
@@ -3765,7 +3812,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
                handled++;
        }
        spin_lock_irq(&conf->device_lock);
-       remaining = --raid_bio->bi_phys_segments;
+       remaining = raid5_dec_bi_phys_segments(raid_bio);
        spin_unlock_irq(&conf->device_lock);
        if (remaining == 0)
                bio_endio(raid_bio, 0);
@@ -3951,7 +3998,6 @@ static int run(mddev_t *mddev)
        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) {
@@ -3960,6 +4006,13 @@ static int run(mddev_t *mddev)
                return -EIO;
        }
 
+       if (mddev->chunk_size < PAGE_SIZE) {
+               printk(KERN_ERR "md/raid5: chunk_size must be at least "
+                      "PAGE_SIZE but %d < %ld\n",
+                      mddev->chunk_size, PAGE_SIZE);
+               return -EINVAL;
+       }
+
        if (mddev->reshape_position != MaxSector) {
                /* Check that we can continue the reshape.
                 * Currently only disks can change, it must
@@ -4054,7 +4107,7 @@ static int run(mddev_t *mddev)
 
        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)
@@ -4237,7 +4290,7 @@ static int stop(mddev_t *mddev)
 }
 
 #ifdef DEBUG
-static void print_sh (struct seq_file *seq, struct stripe_head *sh)
+static void print_sh(struct seq_file *seq, struct stripe_head *sh)
 {
        int i;
 
@@ -4253,7 +4306,7 @@ static void print_sh (struct seq_file *seq, struct stripe_head *sh)
        seq_printf(seq, "\n");
 }
 
-static void printall (struct seq_file *seq, raid5_conf_t *conf)
+static void printall(struct seq_file *seq, raid5_conf_t *conf)
 {
        struct stripe_head *sh;
        struct hlist_node *hn;
@@ -4271,7 +4324,7 @@ static void printall (struct seq_file *seq, raid5_conf_t *conf)
 }
 #endif
 
-static void status (struct seq_file *seq, mddev_t *mddev)
+static void status(struct seq_file *seq, mddev_t *mddev)
 {
        raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
        int i;
@@ -4446,6 +4499,9 @@ static int raid5_check_reshape(mddev_t *mddev)
                return -EINVAL; /* Cannot shrink array or change level yet */
        if (mddev->delta_disks == 0)
                return 0; /* nothing to do */
+       if (mddev->bitmap)
+               /* Cannot grow a bitmap yet */
+               return -EBUSY;
 
        /* Can only proceed if there are plenty of stripe_heads.
         * We need a minimum of one full stripe,, and for sensible progress
@@ -4476,7 +4532,6 @@ static int raid5_start_reshape(mddev_t *mddev)
 {
        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;
@@ -4484,7 +4539,7 @@ static int raid5_start_reshape(mddev_t *mddev)
        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++;
@@ -4506,7 +4561,7 @@ static int raid5_start_reshape(mddev_t *mddev)
        /* 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) {