src/patches/suse-2.6.27.25/patches.fixes/0010-md-raid5-change-raid5_compute_sector-and-stripe_to_p.patch

   1 From 112bf8970dbdfc00bd4667da5996e57c2ce58066 Mon Sep 17 00:00:00 2001
   2 From: NeilBrown <neilb@suse.de>
   3 Date: Tue, 31 Mar 2009 14:39:38 +1100
   4 Subject: [PATCH] md/raid5: change raid5_compute_sector and stripe_to_pdidx to take a 'previous' argument
   5
   6 This similar to the recent change to get_active_stripe.
   7 There is no functional change, just come rearrangement to make
   8 future patches cleaner.
   9
  10 Signed-off-by: NeilBrown <neilb@suse.de>
  11 ---
  12  drivers/md/raid5.c |   78 +++++++++++++++++++++++------------------------------
  13  1 file changed, 34 insertions(+), 44 deletions(-)
  14
  15 --- linux-2.6.27-SLE11_BRANCH.orig/drivers/md/raid5.c
  16 +++ linux-2.6.27-SLE11_BRANCH/drivers/md/raid5.c
  17 @@ -276,7 +276,7 @@ static int grow_buffers(struct stripe_he
  18  }
  19
  20  static void raid5_build_block (struct stripe_head *sh, int i);
  21 -static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks);
  22 +static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int previous);
  23
  24  static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
  25  {
  26 @@ -295,7 +295,7 @@ static void init_stripe(struct stripe_he
  27
  28         sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
  29         sh->sector = sector;
  30 -       sh->pd_idx = stripe_to_pdidx(sector, conf, sh->disks);
  31 +       sh->pd_idx = stripe_to_pdidx(sector, conf, previous);
  32         sh->state = 0;
  33
  34
  35 @@ -1235,15 +1235,18 @@ static void error(mddev_t *mddev, mdk_rd
  36   * Input: a 'big' sector number,
  37   * Output: index of the data and parity disk, and the sector # in them.
  38   */
  39 -static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
  40 -                       unsigned int data_disks, unsigned int * dd_idx,
  41 -                       unsigned int * pd_idx, raid5_conf_t *conf)
  42 +static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
  43 +                                    int previous,
  44 +                                    int *dd_idx, int *pd_idx)
  45  {
  46         long stripe;
  47         unsigned long chunk_number;
  48         unsigned int chunk_offset;
  49         sector_t new_sector;
  50         int sectors_per_chunk = conf->chunk_size >> 9;
  51 +       int raid_disks = previous ? conf->previous_raid_disks
  52 +                                 : conf->raid_disks;
  53 +       int data_disks = raid_disks - conf->max_degraded;
  54
  55         /* First compute the information on this sector */
  56
  57 @@ -1408,7 +1411,9 @@ static sector_t compute_blocknr(struct s
  58         chunk_number = stripe * data_disks + i;
  59         r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
  60
  61 -       check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
  62 +       check = raid5_compute_sector (conf, r_sector,
  63 +                                    (raid_disks != conf->raid_disks),
  64 +                                    &dummy1, &dummy2);
  65         if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
  66                 printk(KERN_ERR "compute_blocknr: map not correct\n");
  67                 return 0;
  68 @@ -1808,16 +1813,18 @@ static int page_is_zero(struct page *p)
  69                 memcmp(a, a+4, STRIPE_SIZE-4)==0);
  70  }
  71
  72 -static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
  73 +static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int previous)
  74  {
  75         int sectors_per_chunk = conf->chunk_size >> 9;
  76         int pd_idx, dd_idx;
  77         int chunk_offset = sector_div(stripe, sectors_per_chunk);
  78 +       int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
  79
  80 -       raid5_compute_sector(stripe * (disks - conf->max_degraded)
  81 +       raid5_compute_sector(conf,
  82 +                            stripe * (disks - conf->max_degraded)
  83                              *sectors_per_chunk + chunk_offset,
  84 -                            disks, disks - conf->max_degraded,
  85 -                            &dd_idx, &pd_idx, conf);
  86 +                            previous,
  87 +                            &dd_idx, &pd_idx);
  88         return pd_idx;
  89  }
  90
  91 @@ -2480,10 +2487,8 @@ static void handle_stripe_expansion(raid
  92                         struct stripe_head *sh2;
  93
  94                         sector_t bn = compute_blocknr(sh, i);
  95 -                       sector_t s = raid5_compute_sector(bn, conf->raid_disks,
  96 -                                               conf->raid_disks -
  97 -                                               conf->max_degraded, &dd_idx,
  98 -                                               &pd_idx, conf);
  99 +                       sector_t s = raid5_compute_sector(conf, bn, 0,
 100 +                                                         &dd_idx, &pd_idx);
 101                         sh2 = get_active_stripe(conf, s, 0, 1);
 102                         if (sh2 == NULL)
 103                                 /* so far only the early blocks of this stripe
 104 @@ -2770,8 +2775,7 @@ static bool handle_stripe5(struct stripe
 105             !sh->reconstruct_state) {
 106                 /* Need to write out all blocks after computing parity */
 107                 sh->disks = conf->raid_disks;
 108 -               sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
 109 -                       conf->raid_disks);
 110 +               sh->pd_idx = stripe_to_pdidx(sh->sector, conf, 0);
 111                 schedule_reconstruction5(sh, &s, 1, 1);
 112         } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
 113                 clear_bit(STRIPE_EXPAND_READY, &sh->state);
 114 @@ -2989,8 +2993,7 @@ static bool handle_stripe6(struct stripe
 115         if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
 116                 /* Need to write out all blocks after computing P&Q */
 117                 sh->disks = conf->raid_disks;
 118 -               sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
 119 -                                            conf->raid_disks);
 120 +               sh->pd_idx = stripe_to_pdidx(sh->sector, conf, 0);
 121                 compute_parity6(sh, RECONSTRUCT_WRITE);
 122                 for (i = conf->raid_disks ; i-- ;  ) {
 123                         set_bit(R5_LOCKED, &sh->dev[i].flags);
 124 @@ -3262,8 +3265,6 @@ static int chunk_aligned_read(struct req
 125  {
 126         mddev_t *mddev = q->queuedata;
 127         raid5_conf_t *conf = mddev_to_conf(mddev);
 128 -       const unsigned int raid_disks = conf->raid_disks;
 129 -       const unsigned int data_disks = raid_disks - conf->max_degraded;
 130         unsigned int dd_idx, pd_idx;
 131         struct bio* align_bi;
 132         mdk_rdev_t *rdev;
 133 @@ -3287,12 +3288,9 @@ static int chunk_aligned_read(struct req
 134         /*
 135          *      compute position
 136          */
 137 -       align_bi->bi_sector =  raid5_compute_sector(raid_bio->bi_sector,
 138 -                                       raid_disks,
 139 -                                       data_disks,
 140 -                                       &dd_idx,
 141 -                                       &pd_idx,
 142 -                                       conf);
 143 +       align_bi->bi_sector =  raid5_compute_sector(conf, raid_bio->bi_sector,
 144 +                                                   0,
 145 +                                                   &dd_idx, &pd_idx);
 146
 147         rcu_read_lock();
 148         rdev = rcu_dereference(conf->disks[dd_idx].rdev);
 149 @@ -3446,8 +3444,9 @@ static int make_request(struct request_q
 150                 }
 151                 data_disks = disks - conf->max_degraded;
 152
 153 -               new_sector = raid5_compute_sector(logical_sector, disks, data_disks,
 154 -                                                 &dd_idx, &pd_idx, conf);
 155 +               new_sector = raid5_compute_sector(conf, logical_sector,
 156 +                                                 previous,
 157 +                                                 &dd_idx, &pd_idx);
 158                 pr_debug("raid5: make_request, sector %llu logical %llu\n",
 159                         (unsigned long long)new_sector,
 160                         (unsigned long long)logical_sector);
 161 @@ -3624,14 +3623,12 @@ static sector_t reshape_request(mddev_t
 162          * block on the destination stripes.
 163          */
 164         first_sector =
 165 -               raid5_compute_sector(sector_nr*(new_data_disks),
 166 -                                    raid_disks, data_disks,
 167 -                                    &dd_idx, &pd_idx, conf);
 168 +               raid5_compute_sector(conf, sector_nr*(new_data_disks),
 169 +                                    1, &dd_idx, &pd_idx);
 170         last_sector =
 171 -               raid5_compute_sector((sector_nr+conf->chunk_size/512)
 172 -                                    *(new_data_disks) -1,
 173 -                                    raid_disks, data_disks,
 174 -                                    &dd_idx, &pd_idx, conf);
 175 +               raid5_compute_sector(conf, ((sector_nr+conf->chunk_size/512)
 176 +                                           *(new_data_disks) - 1),
 177 +                                    1, &dd_idx, &pd_idx);
 178         if (last_sector >= (mddev->size<<1))
 179                 last_sector = (mddev->size<<1)-1;
 180         while (first_sector <= last_sector) {
 181 @@ -3668,8 +3665,6 @@ static inline sector_t sync_request(mdde
 182  {
 183         raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
 184         struct stripe_head *sh;
 185 -       int pd_idx;
 186 -       int raid_disks = conf->raid_disks;
 187         sector_t max_sector = mddev->size << 1;
 188         int sync_blocks;
 189         int still_degraded = 0;
 190 @@ -3724,7 +3719,6 @@ static inline sector_t sync_request(mdde
 191
 192         bitmap_cond_end_sync(mddev->bitmap, sector_nr);
 193
 194 -       pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
 195         sh = get_active_stripe(conf, sector_nr, 0, 1);
 196         if (sh == NULL) {
 197                 sh = get_active_stripe(conf, sector_nr, 0, 0);
 198 @@ -3776,12 +3770,8 @@ static int  retry_aligned_read(raid5_con
 199         int handled = 0;
 200
 201         logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
 202 -       sector = raid5_compute_sector(  logical_sector,
 203 -                                       conf->raid_disks,
 204 -                                       conf->raid_disks - conf->max_degraded,
 205 -                                       &dd_idx,
 206 -                                       &pd_idx,
 207 -                                       conf);
 208 +       sector = raid5_compute_sector(conf, logical_sector,
 209 +                                     0, &dd_idx, &pd_idx);
 210         last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9);
 211
 212         for (; logical_sector < last_sector;