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-rw-r--r--drivers/md/raid5.c1059
1 files changed, 988 insertions, 71 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 122e64e557b1..9ba73074df04 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2,8 +2,11 @@
2 * raid5.c : Multiple Devices driver for Linux 2 * raid5.c : Multiple Devices driver for Linux
3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman 3 * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
4 * Copyright (C) 1999, 2000 Ingo Molnar 4 * Copyright (C) 1999, 2000 Ingo Molnar
5 * Copyright (C) 2002, 2003 H. Peter Anvin
5 * 6 *
6 * RAID-5 management functions. 7 * RAID-4/5/6 management functions.
8 * Thanks to Penguin Computing for making the RAID-6 development possible
9 * by donating a test server!
7 * 10 *
8 * This program is free software; you can redistribute it and/or modify 11 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by 12 * it under the terms of the GNU General Public License as published by
@@ -19,11 +22,11 @@
19#include <linux/config.h> 22#include <linux/config.h>
20#include <linux/module.h> 23#include <linux/module.h>
21#include <linux/slab.h> 24#include <linux/slab.h>
22#include <linux/raid/raid5.h>
23#include <linux/highmem.h> 25#include <linux/highmem.h>
24#include <linux/bitops.h> 26#include <linux/bitops.h>
25#include <linux/kthread.h> 27#include <linux/kthread.h>
26#include <asm/atomic.h> 28#include <asm/atomic.h>
29#include "raid6.h"
27 30
28#include <linux/raid/bitmap.h> 31#include <linux/raid/bitmap.h>
29 32
@@ -68,6 +71,16 @@
68#define __inline__ 71#define __inline__
69#endif 72#endif
70 73
74#if !RAID6_USE_EMPTY_ZERO_PAGE
75/* In .bss so it's zeroed */
76const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
77#endif
78
79static inline int raid6_next_disk(int disk, int raid_disks)
80{
81 disk++;
82 return (disk < raid_disks) ? disk : 0;
83}
71static void print_raid5_conf (raid5_conf_t *conf); 84static void print_raid5_conf (raid5_conf_t *conf);
72 85
73static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) 86static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
@@ -104,7 +117,7 @@ static void release_stripe(struct stripe_head *sh)
104{ 117{
105 raid5_conf_t *conf = sh->raid_conf; 118 raid5_conf_t *conf = sh->raid_conf;
106 unsigned long flags; 119 unsigned long flags;
107 120
108 spin_lock_irqsave(&conf->device_lock, flags); 121 spin_lock_irqsave(&conf->device_lock, flags);
109 __release_stripe(conf, sh); 122 __release_stripe(conf, sh);
110 spin_unlock_irqrestore(&conf->device_lock, flags); 123 spin_unlock_irqrestore(&conf->device_lock, flags);
@@ -117,7 +130,7 @@ static inline void remove_hash(struct stripe_head *sh)
117 hlist_del_init(&sh->hash); 130 hlist_del_init(&sh->hash);
118} 131}
119 132
120static void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) 133static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
121{ 134{
122 struct hlist_head *hp = stripe_hash(conf, sh->sector); 135 struct hlist_head *hp = stripe_hash(conf, sh->sector);
123 136
@@ -190,7 +203,7 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int
190 (unsigned long long)sh->sector); 203 (unsigned long long)sh->sector);
191 204
192 remove_hash(sh); 205 remove_hash(sh);
193 206
194 sh->sector = sector; 207 sh->sector = sector;
195 sh->pd_idx = pd_idx; 208 sh->pd_idx = pd_idx;
196 sh->state = 0; 209 sh->state = 0;
@@ -269,8 +282,9 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector
269 } else { 282 } else {
270 if (!test_bit(STRIPE_HANDLE, &sh->state)) 283 if (!test_bit(STRIPE_HANDLE, &sh->state))
271 atomic_inc(&conf->active_stripes); 284 atomic_inc(&conf->active_stripes);
272 if (!list_empty(&sh->lru)) 285 if (list_empty(&sh->lru))
273 list_del_init(&sh->lru); 286 BUG();
287 list_del_init(&sh->lru);
274 } 288 }
275 } 289 }
276 } while (sh == NULL); 290 } while (sh == NULL);
@@ -321,10 +335,9 @@ static int grow_stripes(raid5_conf_t *conf, int num)
321 return 1; 335 return 1;
322 conf->slab_cache = sc; 336 conf->slab_cache = sc;
323 conf->pool_size = devs; 337 conf->pool_size = devs;
324 while (num--) { 338 while (num--)
325 if (!grow_one_stripe(conf)) 339 if (!grow_one_stripe(conf))
326 return 1; 340 return 1;
327 }
328 return 0; 341 return 0;
329} 342}
330 343
@@ -631,8 +644,7 @@ static void raid5_build_block (struct stripe_head *sh, int i)
631 dev->req.bi_private = sh; 644 dev->req.bi_private = sh;
632 645
633 dev->flags = 0; 646 dev->flags = 0;
634 if (i != sh->pd_idx) 647 dev->sector = compute_blocknr(sh, i);
635 dev->sector = compute_blocknr(sh, i);
636} 648}
637 649
638static void error(mddev_t *mddev, mdk_rdev_t *rdev) 650static void error(mddev_t *mddev, mdk_rdev_t *rdev)
@@ -659,7 +671,7 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
659 " Operation continuing on %d devices\n", 671 " Operation continuing on %d devices\n",
660 bdevname(rdev->bdev,b), conf->working_disks); 672 bdevname(rdev->bdev,b), conf->working_disks);
661 } 673 }
662} 674}
663 675
664/* 676/*
665 * Input: a 'big' sector number, 677 * Input: a 'big' sector number,
@@ -697,9 +709,12 @@ static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
697 /* 709 /*
698 * Select the parity disk based on the user selected algorithm. 710 * Select the parity disk based on the user selected algorithm.
699 */ 711 */
700 if (conf->level == 4) 712 switch(conf->level) {
713 case 4:
701 *pd_idx = data_disks; 714 *pd_idx = data_disks;
702 else switch (conf->algorithm) { 715 break;
716 case 5:
717 switch (conf->algorithm) {
703 case ALGORITHM_LEFT_ASYMMETRIC: 718 case ALGORITHM_LEFT_ASYMMETRIC:
704 *pd_idx = data_disks - stripe % raid_disks; 719 *pd_idx = data_disks - stripe % raid_disks;
705 if (*dd_idx >= *pd_idx) 720 if (*dd_idx >= *pd_idx)
@@ -721,6 +736,39 @@ static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
721 default: 736 default:
722 printk(KERN_ERR "raid5: unsupported algorithm %d\n", 737 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
723 conf->algorithm); 738 conf->algorithm);
739 }
740 break;
741 case 6:
742
743 /**** FIX THIS ****/
744 switch (conf->algorithm) {
745 case ALGORITHM_LEFT_ASYMMETRIC:
746 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
747 if (*pd_idx == raid_disks-1)
748 (*dd_idx)++; /* Q D D D P */
749 else if (*dd_idx >= *pd_idx)
750 (*dd_idx) += 2; /* D D P Q D */
751 break;
752 case ALGORITHM_RIGHT_ASYMMETRIC:
753 *pd_idx = stripe % raid_disks;
754 if (*pd_idx == raid_disks-1)
755 (*dd_idx)++; /* Q D D D P */
756 else if (*dd_idx >= *pd_idx)
757 (*dd_idx) += 2; /* D D P Q D */
758 break;
759 case ALGORITHM_LEFT_SYMMETRIC:
760 *pd_idx = raid_disks - 1 - (stripe % raid_disks);
761 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
762 break;
763 case ALGORITHM_RIGHT_SYMMETRIC:
764 *pd_idx = stripe % raid_disks;
765 *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
766 break;
767 default:
768 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
769 conf->algorithm);
770 }
771 break;
724 } 772 }
725 773
726 /* 774 /*
@@ -742,12 +790,17 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
742 int chunk_number, dummy1, dummy2, dd_idx = i; 790 int chunk_number, dummy1, dummy2, dd_idx = i;
743 sector_t r_sector; 791 sector_t r_sector;
744 792
793
745 chunk_offset = sector_div(new_sector, sectors_per_chunk); 794 chunk_offset = sector_div(new_sector, sectors_per_chunk);
746 stripe = new_sector; 795 stripe = new_sector;
747 BUG_ON(new_sector != stripe); 796 BUG_ON(new_sector != stripe);
748 797
749 798 if (i == sh->pd_idx)
750 switch (conf->algorithm) { 799 return 0;
800 switch(conf->level) {
801 case 4: break;
802 case 5:
803 switch (conf->algorithm) {
751 case ALGORITHM_LEFT_ASYMMETRIC: 804 case ALGORITHM_LEFT_ASYMMETRIC:
752 case ALGORITHM_RIGHT_ASYMMETRIC: 805 case ALGORITHM_RIGHT_ASYMMETRIC:
753 if (i > sh->pd_idx) 806 if (i > sh->pd_idx)
@@ -761,7 +814,37 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
761 break; 814 break;
762 default: 815 default:
763 printk(KERN_ERR "raid5: unsupported algorithm %d\n", 816 printk(KERN_ERR "raid5: unsupported algorithm %d\n",
817 conf->algorithm);
818 }
819 break;
820 case 6:
821 data_disks = raid_disks - 2;
822 if (i == raid6_next_disk(sh->pd_idx, raid_disks))
823 return 0; /* It is the Q disk */
824 switch (conf->algorithm) {
825 case ALGORITHM_LEFT_ASYMMETRIC:
826 case ALGORITHM_RIGHT_ASYMMETRIC:
827 if (sh->pd_idx == raid_disks-1)
828 i--; /* Q D D D P */
829 else if (i > sh->pd_idx)
830 i -= 2; /* D D P Q D */
831 break;
832 case ALGORITHM_LEFT_SYMMETRIC:
833 case ALGORITHM_RIGHT_SYMMETRIC:
834 if (sh->pd_idx == raid_disks-1)
835 i--; /* Q D D D P */
836 else {
837 /* D D P Q D */
838 if (i < sh->pd_idx)
839 i += raid_disks;
840 i -= (sh->pd_idx + 2);
841 }
842 break;
843 default:
844 printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
764 conf->algorithm); 845 conf->algorithm);
846 }
847 break;
765 } 848 }
766 849
767 chunk_number = stripe * data_disks + i; 850 chunk_number = stripe * data_disks + i;
@@ -778,10 +861,11 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
778 861
779 862
780/* 863/*
781 * Copy data between a page in the stripe cache, and a bio. 864 * Copy data between a page in the stripe cache, and one or more bion
782 * There are no alignment or size guarantees between the page or the 865 * The page could align with the middle of the bio, or there could be
783 * bio except that there is some overlap. 866 * several bion, each with several bio_vecs, which cover part of the page
784 * All iovecs in the bio must be considered. 867 * Multiple bion are linked together on bi_next. There may be extras
868 * at the end of this list. We ignore them.
785 */ 869 */
786static void copy_data(int frombio, struct bio *bio, 870static void copy_data(int frombio, struct bio *bio,
787 struct page *page, 871 struct page *page,
@@ -810,7 +894,7 @@ static void copy_data(int frombio, struct bio *bio,
810 if (len > 0 && page_offset + len > STRIPE_SIZE) 894 if (len > 0 && page_offset + len > STRIPE_SIZE)
811 clen = STRIPE_SIZE - page_offset; 895 clen = STRIPE_SIZE - page_offset;
812 else clen = len; 896 else clen = len;
813 897
814 if (clen > 0) { 898 if (clen > 0) {
815 char *ba = __bio_kmap_atomic(bio, i, KM_USER0); 899 char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
816 if (frombio) 900 if (frombio)
@@ -862,14 +946,14 @@ static void compute_block(struct stripe_head *sh, int dd_idx)
862 set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags); 946 set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
863} 947}
864 948
865static void compute_parity(struct stripe_head *sh, int method) 949static void compute_parity5(struct stripe_head *sh, int method)
866{ 950{
867 raid5_conf_t *conf = sh->raid_conf; 951 raid5_conf_t *conf = sh->raid_conf;
868 int i, pd_idx = sh->pd_idx, disks = sh->disks, count; 952 int i, pd_idx = sh->pd_idx, disks = sh->disks, count;
869 void *ptr[MAX_XOR_BLOCKS]; 953 void *ptr[MAX_XOR_BLOCKS];
870 struct bio *chosen; 954 struct bio *chosen;
871 955
872 PRINTK("compute_parity, stripe %llu, method %d\n", 956 PRINTK("compute_parity5, stripe %llu, method %d\n",
873 (unsigned long long)sh->sector, method); 957 (unsigned long long)sh->sector, method);
874 958
875 count = 1; 959 count = 1;
@@ -956,9 +1040,195 @@ static void compute_parity(struct stripe_head *sh, int method)
956 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); 1040 clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
957} 1041}
958 1042
1043static void compute_parity6(struct stripe_head *sh, int method)
1044{
1045 raid6_conf_t *conf = sh->raid_conf;
1046 int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count;
1047 struct bio *chosen;
1048 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1049 void *ptrs[disks];
1050
1051 qd_idx = raid6_next_disk(pd_idx, disks);
1052 d0_idx = raid6_next_disk(qd_idx, disks);
1053
1054 PRINTK("compute_parity, stripe %llu, method %d\n",
1055 (unsigned long long)sh->sector, method);
1056
1057 switch(method) {
1058 case READ_MODIFY_WRITE:
1059 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1060 case RECONSTRUCT_WRITE:
1061 for (i= disks; i-- ;)
1062 if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
1063 chosen = sh->dev[i].towrite;
1064 sh->dev[i].towrite = NULL;
1065
1066 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
1067 wake_up(&conf->wait_for_overlap);
1068
1069 if (sh->dev[i].written) BUG();
1070 sh->dev[i].written = chosen;
1071 }
1072 break;
1073 case CHECK_PARITY:
1074 BUG(); /* Not implemented yet */
1075 }
1076
1077 for (i = disks; i--;)
1078 if (sh->dev[i].written) {
1079 sector_t sector = sh->dev[i].sector;
1080 struct bio *wbi = sh->dev[i].written;
1081 while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
1082 copy_data(1, wbi, sh->dev[i].page, sector);
1083 wbi = r5_next_bio(wbi, sector);
1084 }
1085
1086 set_bit(R5_LOCKED, &sh->dev[i].flags);
1087 set_bit(R5_UPTODATE, &sh->dev[i].flags);
1088 }
1089
1090// switch(method) {
1091// case RECONSTRUCT_WRITE:
1092// case CHECK_PARITY:
1093// case UPDATE_PARITY:
1094 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1095 /* FIX: Is this ordering of drives even remotely optimal? */
1096 count = 0;
1097 i = d0_idx;
1098 do {
1099 ptrs[count++] = page_address(sh->dev[i].page);
1100 if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1101 printk("block %d/%d not uptodate on parity calc\n", i,count);
1102 i = raid6_next_disk(i, disks);
1103 } while ( i != d0_idx );
1104// break;
1105// }
1106
1107 raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs);
1108
1109 switch(method) {
1110 case RECONSTRUCT_WRITE:
1111 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1112 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1113 set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
1114 set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
1115 break;
1116 case UPDATE_PARITY:
1117 set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
1118 set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
1119 break;
1120 }
1121}
1122
1123
1124/* Compute one missing block */
1125static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
1126{
1127 raid6_conf_t *conf = sh->raid_conf;
1128 int i, count, disks = conf->raid_disks;
1129 void *ptr[MAX_XOR_BLOCKS], *p;
1130 int pd_idx = sh->pd_idx;
1131 int qd_idx = raid6_next_disk(pd_idx, disks);
1132
1133 PRINTK("compute_block_1, stripe %llu, idx %d\n",
1134 (unsigned long long)sh->sector, dd_idx);
1135
1136 if ( dd_idx == qd_idx ) {
1137 /* We're actually computing the Q drive */
1138 compute_parity6(sh, UPDATE_PARITY);
1139 } else {
1140 ptr[0] = page_address(sh->dev[dd_idx].page);
1141 if (!nozero) memset(ptr[0], 0, STRIPE_SIZE);
1142 count = 1;
1143 for (i = disks ; i--; ) {
1144 if (i == dd_idx || i == qd_idx)
1145 continue;
1146 p = page_address(sh->dev[i].page);
1147 if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
1148 ptr[count++] = p;
1149 else
1150 printk("compute_block() %d, stripe %llu, %d"
1151 " not present\n", dd_idx,
1152 (unsigned long long)sh->sector, i);
1153
1154 check_xor();
1155 }
1156 if (count != 1)
1157 xor_block(count, STRIPE_SIZE, ptr);
1158 if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1159 else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
1160 }
1161}
1162
1163/* Compute two missing blocks */
1164static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
1165{
1166 raid6_conf_t *conf = sh->raid_conf;
1167 int i, count, disks = conf->raid_disks;
1168 int pd_idx = sh->pd_idx;
1169 int qd_idx = raid6_next_disk(pd_idx, disks);
1170 int d0_idx = raid6_next_disk(qd_idx, disks);
1171 int faila, failb;
1172
1173 /* faila and failb are disk numbers relative to d0_idx */
1174 /* pd_idx become disks-2 and qd_idx become disks-1 */
1175 faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx;
1176 failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx;
1177
1178 BUG_ON(faila == failb);
1179 if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
1180
1181 PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1182 (unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb);
1183
1184 if ( failb == disks-1 ) {
1185 /* Q disk is one of the missing disks */
1186 if ( faila == disks-2 ) {
1187 /* Missing P+Q, just recompute */
1188 compute_parity6(sh, UPDATE_PARITY);
1189 return;
1190 } else {
1191 /* We're missing D+Q; recompute D from P */
1192 compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1, 0);
1193 compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
1194 return;
1195 }
1196 }
1197
1198 /* We're missing D+P or D+D; build pointer table */
1199 {
1200 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1201 void *ptrs[disks];
1202
1203 count = 0;
1204 i = d0_idx;
1205 do {
1206 ptrs[count++] = page_address(sh->dev[i].page);
1207 i = raid6_next_disk(i, disks);
1208 if (i != dd_idx1 && i != dd_idx2 &&
1209 !test_bit(R5_UPTODATE, &sh->dev[i].flags))
1210 printk("compute_2 with missing block %d/%d\n", count, i);
1211 } while ( i != d0_idx );
1212
1213 if ( failb == disks-2 ) {
1214 /* We're missing D+P. */
1215 raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs);
1216 } else {
1217 /* We're missing D+D. */
1218 raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs);
1219 }
1220
1221 /* Both the above update both missing blocks */
1222 set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
1223 set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
1224 }
1225}
1226
1227
1228
959/* 1229/*
960 * Each stripe/dev can have one or more bion attached. 1230 * Each stripe/dev can have one or more bion attached.
961 * toread/towrite point to the first in a chain. 1231 * toread/towrite point to the first in a chain.
962 * The bi_next chain must be in order. 1232 * The bi_next chain must be in order.
963 */ 1233 */
964static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite) 1234static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
@@ -1031,6 +1301,13 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
1031 1301
1032static void end_reshape(raid5_conf_t *conf); 1302static void end_reshape(raid5_conf_t *conf);
1033 1303
1304static int page_is_zero(struct page *p)
1305{
1306 char *a = page_address(p);
1307 return ((*(u32*)a) == 0 &&
1308 memcmp(a, a+4, STRIPE_SIZE-4)==0);
1309}
1310
1034static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks) 1311static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
1035{ 1312{
1036 int sectors_per_chunk = conf->chunk_size >> 9; 1313 int sectors_per_chunk = conf->chunk_size >> 9;
@@ -1062,7 +1339,7 @@ static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
1062 * 1339 *
1063 */ 1340 */
1064 1341
1065static void handle_stripe(struct stripe_head *sh) 1342static void handle_stripe5(struct stripe_head *sh)
1066{ 1343{
1067 raid5_conf_t *conf = sh->raid_conf; 1344 raid5_conf_t *conf = sh->raid_conf;
1068 int disks = sh->disks; 1345 int disks = sh->disks;
@@ -1394,7 +1671,7 @@ static void handle_stripe(struct stripe_head *sh)
1394 if (locked == 0 && (rcw == 0 ||rmw == 0) && 1671 if (locked == 0 && (rcw == 0 ||rmw == 0) &&
1395 !test_bit(STRIPE_BIT_DELAY, &sh->state)) { 1672 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
1396 PRINTK("Computing parity...\n"); 1673 PRINTK("Computing parity...\n");
1397 compute_parity(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE); 1674 compute_parity5(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE);
1398 /* now every locked buffer is ready to be written */ 1675 /* now every locked buffer is ready to be written */
1399 for (i=disks; i--;) 1676 for (i=disks; i--;)
1400 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) { 1677 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
@@ -1421,13 +1698,10 @@ static void handle_stripe(struct stripe_head *sh)
1421 !test_bit(STRIPE_INSYNC, &sh->state)) { 1698 !test_bit(STRIPE_INSYNC, &sh->state)) {
1422 set_bit(STRIPE_HANDLE, &sh->state); 1699 set_bit(STRIPE_HANDLE, &sh->state);
1423 if (failed == 0) { 1700 if (failed == 0) {
1424 char *pagea;
1425 BUG_ON(uptodate != disks); 1701 BUG_ON(uptodate != disks);
1426 compute_parity(sh, CHECK_PARITY); 1702 compute_parity5(sh, CHECK_PARITY);
1427 uptodate--; 1703 uptodate--;
1428 pagea = page_address(sh->dev[sh->pd_idx].page); 1704 if (page_is_zero(sh->dev[sh->pd_idx].page)) {
1429 if ((*(u32*)pagea) == 0 &&
1430 !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) {
1431 /* parity is correct (on disc, not in buffer any more) */ 1705 /* parity is correct (on disc, not in buffer any more) */
1432 set_bit(STRIPE_INSYNC, &sh->state); 1706 set_bit(STRIPE_INSYNC, &sh->state);
1433 } else { 1707 } else {
@@ -1487,7 +1761,7 @@ static void handle_stripe(struct stripe_head *sh)
1487 /* Need to write out all blocks after computing parity */ 1761 /* Need to write out all blocks after computing parity */
1488 sh->disks = conf->raid_disks; 1762 sh->disks = conf->raid_disks;
1489 sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks); 1763 sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks);
1490 compute_parity(sh, RECONSTRUCT_WRITE); 1764 compute_parity5(sh, RECONSTRUCT_WRITE);
1491 for (i= conf->raid_disks; i--;) { 1765 for (i= conf->raid_disks; i--;) {
1492 set_bit(R5_LOCKED, &sh->dev[i].flags); 1766 set_bit(R5_LOCKED, &sh->dev[i].flags);
1493 locked++; 1767 locked++;
@@ -1615,6 +1889,569 @@ static void handle_stripe(struct stripe_head *sh)
1615 } 1889 }
1616} 1890}
1617 1891
1892static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
1893{
1894 raid6_conf_t *conf = sh->raid_conf;
1895 int disks = conf->raid_disks;
1896 struct bio *return_bi= NULL;
1897 struct bio *bi;
1898 int i;
1899 int syncing;
1900 int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
1901 int non_overwrite = 0;
1902 int failed_num[2] = {0, 0};
1903 struct r5dev *dev, *pdev, *qdev;
1904 int pd_idx = sh->pd_idx;
1905 int qd_idx = raid6_next_disk(pd_idx, disks);
1906 int p_failed, q_failed;
1907
1908 PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n",
1909 (unsigned long long)sh->sector, sh->state, atomic_read(&sh->count),
1910 pd_idx, qd_idx);
1911
1912 spin_lock(&sh->lock);
1913 clear_bit(STRIPE_HANDLE, &sh->state);
1914 clear_bit(STRIPE_DELAYED, &sh->state);
1915
1916 syncing = test_bit(STRIPE_SYNCING, &sh->state);
1917 /* Now to look around and see what can be done */
1918
1919 rcu_read_lock();
1920 for (i=disks; i--; ) {
1921 mdk_rdev_t *rdev;
1922 dev = &sh->dev[i];
1923 clear_bit(R5_Insync, &dev->flags);
1924
1925 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
1926 i, dev->flags, dev->toread, dev->towrite, dev->written);
1927 /* maybe we can reply to a read */
1928 if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
1929 struct bio *rbi, *rbi2;
1930 PRINTK("Return read for disc %d\n", i);
1931 spin_lock_irq(&conf->device_lock);
1932 rbi = dev->toread;
1933 dev->toread = NULL;
1934 if (test_and_clear_bit(R5_Overlap, &dev->flags))
1935 wake_up(&conf->wait_for_overlap);
1936 spin_unlock_irq(&conf->device_lock);
1937 while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
1938 copy_data(0, rbi, dev->page, dev->sector);
1939 rbi2 = r5_next_bio(rbi, dev->sector);
1940 spin_lock_irq(&conf->device_lock);
1941 if (--rbi->bi_phys_segments == 0) {
1942 rbi->bi_next = return_bi;
1943 return_bi = rbi;
1944 }
1945 spin_unlock_irq(&conf->device_lock);
1946 rbi = rbi2;
1947 }
1948 }
1949
1950 /* now count some things */
1951 if (test_bit(R5_LOCKED, &dev->flags)) locked++;
1952 if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++;
1953
1954
1955 if (dev->toread) to_read++;
1956 if (dev->towrite) {
1957 to_write++;
1958 if (!test_bit(R5_OVERWRITE, &dev->flags))
1959 non_overwrite++;
1960 }
1961 if (dev->written) written++;
1962 rdev = rcu_dereference(conf->disks[i].rdev);
1963 if (!rdev || !test_bit(In_sync, &rdev->flags)) {
1964 /* The ReadError flag will just be confusing now */
1965 clear_bit(R5_ReadError, &dev->flags);
1966 clear_bit(R5_ReWrite, &dev->flags);
1967 }
1968 if (!rdev || !test_bit(In_sync, &rdev->flags)
1969 || test_bit(R5_ReadError, &dev->flags)) {
1970 if ( failed < 2 )
1971 failed_num[failed] = i;
1972 failed++;
1973 } else
1974 set_bit(R5_Insync, &dev->flags);
1975 }
1976 rcu_read_unlock();
1977 PRINTK("locked=%d uptodate=%d to_read=%d"
1978 " to_write=%d failed=%d failed_num=%d,%d\n",
1979 locked, uptodate, to_read, to_write, failed,
1980 failed_num[0], failed_num[1]);
1981 /* check if the array has lost >2 devices and, if so, some requests might
1982 * need to be failed
1983 */
1984 if (failed > 2 && to_read+to_write+written) {
1985 for (i=disks; i--; ) {
1986 int bitmap_end = 0;
1987
1988 if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
1989 mdk_rdev_t *rdev;
1990 rcu_read_lock();
1991 rdev = rcu_dereference(conf->disks[i].rdev);
1992 if (rdev && test_bit(In_sync, &rdev->flags))
1993 /* multiple read failures in one stripe */
1994 md_error(conf->mddev, rdev);
1995 rcu_read_unlock();
1996 }
1997
1998 spin_lock_irq(&conf->device_lock);
1999 /* fail all writes first */
2000 bi = sh->dev[i].towrite;
2001 sh->dev[i].towrite = NULL;
2002 if (bi) { to_write--; bitmap_end = 1; }
2003
2004 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2005 wake_up(&conf->wait_for_overlap);
2006
2007 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
2008 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2009 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2010 if (--bi->bi_phys_segments == 0) {
2011 md_write_end(conf->mddev);
2012 bi->bi_next = return_bi;
2013 return_bi = bi;
2014 }
2015 bi = nextbi;
2016 }
2017 /* and fail all 'written' */
2018 bi = sh->dev[i].written;
2019 sh->dev[i].written = NULL;
2020 if (bi) bitmap_end = 1;
2021 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) {
2022 struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
2023 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2024 if (--bi->bi_phys_segments == 0) {
2025 md_write_end(conf->mddev);
2026 bi->bi_next = return_bi;
2027 return_bi = bi;
2028 }
2029 bi = bi2;
2030 }
2031
2032 /* fail any reads if this device is non-operational */
2033 if (!test_bit(R5_Insync, &sh->dev[i].flags) ||
2034 test_bit(R5_ReadError, &sh->dev[i].flags)) {
2035 bi = sh->dev[i].toread;
2036 sh->dev[i].toread = NULL;
2037 if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
2038 wake_up(&conf->wait_for_overlap);
2039 if (bi) to_read--;
2040 while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
2041 struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
2042 clear_bit(BIO_UPTODATE, &bi->bi_flags);
2043 if (--bi->bi_phys_segments == 0) {
2044 bi->bi_next = return_bi;
2045 return_bi = bi;
2046 }
2047 bi = nextbi;
2048 }
2049 }
2050 spin_unlock_irq(&conf->device_lock);
2051 if (bitmap_end)
2052 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2053 STRIPE_SECTORS, 0, 0);
2054 }
2055 }
2056 if (failed > 2 && syncing) {
2057 md_done_sync(conf->mddev, STRIPE_SECTORS,0);
2058 clear_bit(STRIPE_SYNCING, &sh->state);
2059 syncing = 0;
2060 }
2061
2062 /*
2063 * might be able to return some write requests if the parity blocks
2064 * are safe, or on a failed drive
2065 */
2066 pdev = &sh->dev[pd_idx];
2067 p_failed = (failed >= 1 && failed_num[0] == pd_idx)
2068 || (failed >= 2 && failed_num[1] == pd_idx);
2069 qdev = &sh->dev[qd_idx];
2070 q_failed = (failed >= 1 && failed_num[0] == qd_idx)
2071 || (failed >= 2 && failed_num[1] == qd_idx);
2072
2073 if ( written &&
2074 ( p_failed || ((test_bit(R5_Insync, &pdev->flags)
2075 && !test_bit(R5_LOCKED, &pdev->flags)
2076 && test_bit(R5_UPTODATE, &pdev->flags))) ) &&
2077 ( q_failed || ((test_bit(R5_Insync, &qdev->flags)
2078 && !test_bit(R5_LOCKED, &qdev->flags)
2079 && test_bit(R5_UPTODATE, &qdev->flags))) ) ) {
2080 /* any written block on an uptodate or failed drive can be
2081 * returned. Note that if we 'wrote' to a failed drive,
2082 * it will be UPTODATE, but never LOCKED, so we don't need
2083 * to test 'failed' directly.
2084 */
2085 for (i=disks; i--; )
2086 if (sh->dev[i].written) {
2087 dev = &sh->dev[i];
2088 if (!test_bit(R5_LOCKED, &dev->flags) &&
2089 test_bit(R5_UPTODATE, &dev->flags) ) {
2090 /* We can return any write requests */
2091 int bitmap_end = 0;
2092 struct bio *wbi, *wbi2;
2093 PRINTK("Return write for stripe %llu disc %d\n",
2094 (unsigned long long)sh->sector, i);
2095 spin_lock_irq(&conf->device_lock);
2096 wbi = dev->written;
2097 dev->written = NULL;
2098 while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) {
2099 wbi2 = r5_next_bio(wbi, dev->sector);
2100 if (--wbi->bi_phys_segments == 0) {
2101 md_write_end(conf->mddev);
2102 wbi->bi_next = return_bi;
2103 return_bi = wbi;
2104 }
2105 wbi = wbi2;
2106 }
2107 if (dev->towrite == NULL)
2108 bitmap_end = 1;
2109 spin_unlock_irq(&conf->device_lock);
2110 if (bitmap_end)
2111 bitmap_endwrite(conf->mddev->bitmap, sh->sector,
2112 STRIPE_SECTORS,
2113 !test_bit(STRIPE_DEGRADED, &sh->state), 0);
2114 }
2115 }
2116 }
2117
2118 /* Now we might consider reading some blocks, either to check/generate
2119 * parity, or to satisfy requests
2120 * or to load a block that is being partially written.
2121 */
2122 if (to_read || non_overwrite || (to_write && failed) || (syncing && (uptodate < disks))) {
2123 for (i=disks; i--;) {
2124 dev = &sh->dev[i];
2125 if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
2126 (dev->toread ||
2127 (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
2128 syncing ||
2129 (failed >= 1 && (sh->dev[failed_num[0]].toread || to_write)) ||
2130 (failed >= 2 && (sh->dev[failed_num[1]].toread || to_write))
2131 )
2132 ) {
2133 /* we would like to get this block, possibly
2134 * by computing it, but we might not be able to
2135 */
2136 if (uptodate == disks-1) {
2137 PRINTK("Computing stripe %llu block %d\n",
2138 (unsigned long long)sh->sector, i);
2139 compute_block_1(sh, i, 0);
2140 uptodate++;
2141 } else if ( uptodate == disks-2 && failed >= 2 ) {
2142 /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */
2143 int other;
2144 for (other=disks; other--;) {
2145 if ( other == i )
2146 continue;
2147 if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) )
2148 break;
2149 }
2150 BUG_ON(other < 0);
2151 PRINTK("Computing stripe %llu blocks %d,%d\n",
2152 (unsigned long long)sh->sector, i, other);
2153 compute_block_2(sh, i, other);
2154 uptodate += 2;
2155 } else if (test_bit(R5_Insync, &dev->flags)) {
2156 set_bit(R5_LOCKED, &dev->flags);
2157 set_bit(R5_Wantread, &dev->flags);
2158#if 0
2159 /* if I am just reading this block and we don't have
2160 a failed drive, or any pending writes then sidestep the cache */
2161 if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
2162 ! syncing && !failed && !to_write) {
2163 sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page;
2164 sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data;
2165 }
2166#endif
2167 locked++;
2168 PRINTK("Reading block %d (sync=%d)\n",
2169 i, syncing);
2170 }
2171 }
2172 }
2173 set_bit(STRIPE_HANDLE, &sh->state);
2174 }
2175
2176 /* now to consider writing and what else, if anything should be read */
2177 if (to_write) {
2178 int rcw=0, must_compute=0;
2179 for (i=disks ; i--;) {
2180 dev = &sh->dev[i];
2181 /* Would I have to read this buffer for reconstruct_write */
2182 if (!test_bit(R5_OVERWRITE, &dev->flags)
2183 && i != pd_idx && i != qd_idx
2184 && (!test_bit(R5_LOCKED, &dev->flags)
2185#if 0
2186 || sh->bh_page[i] != bh->b_page
2187#endif
2188 ) &&
2189 !test_bit(R5_UPTODATE, &dev->flags)) {
2190 if (test_bit(R5_Insync, &dev->flags)) rcw++;
2191 else {
2192 PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags);
2193 must_compute++;
2194 }
2195 }
2196 }
2197 PRINTK("for sector %llu, rcw=%d, must_compute=%d\n",
2198 (unsigned long long)sh->sector, rcw, must_compute);
2199 set_bit(STRIPE_HANDLE, &sh->state);
2200
2201 if (rcw > 0)
2202 /* want reconstruct write, but need to get some data */
2203 for (i=disks; i--;) {
2204 dev = &sh->dev[i];
2205 if (!test_bit(R5_OVERWRITE, &dev->flags)
2206 && !(failed == 0 && (i == pd_idx || i == qd_idx))
2207 && !test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
2208 test_bit(R5_Insync, &dev->flags)) {
2209 if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
2210 {
2211 PRINTK("Read_old stripe %llu block %d for Reconstruct\n",
2212 (unsigned long long)sh->sector, i);
2213 set_bit(R5_LOCKED, &dev->flags);
2214 set_bit(R5_Wantread, &dev->flags);
2215 locked++;
2216 } else {
2217 PRINTK("Request delayed stripe %llu block %d for Reconstruct\n",
2218 (unsigned long long)sh->sector, i);
2219 set_bit(STRIPE_DELAYED, &sh->state);
2220 set_bit(STRIPE_HANDLE, &sh->state);
2221 }
2222 }
2223 }
2224 /* now if nothing is locked, and if we have enough data, we can start a write request */
2225 if (locked == 0 && rcw == 0 &&
2226 !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
2227 if ( must_compute > 0 ) {
2228 /* We have failed blocks and need to compute them */
2229 switch ( failed ) {
2230 case 0: BUG();
2231 case 1: compute_block_1(sh, failed_num[0], 0); break;
2232 case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break;
2233 default: BUG(); /* This request should have been failed? */
2234 }
2235 }
2236
2237 PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector);
2238 compute_parity6(sh, RECONSTRUCT_WRITE);
2239 /* now every locked buffer is ready to be written */
2240 for (i=disks; i--;)
2241 if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
2242 PRINTK("Writing stripe %llu block %d\n",
2243 (unsigned long long)sh->sector, i);
2244 locked++;
2245 set_bit(R5_Wantwrite, &sh->dev[i].flags);
2246 }
2247 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2248 set_bit(STRIPE_INSYNC, &sh->state);
2249
2250 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
2251 atomic_dec(&conf->preread_active_stripes);
2252 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
2253 md_wakeup_thread(conf->mddev->thread);
2254 }
2255 }
2256 }
2257
2258 /* maybe we need to check and possibly fix the parity for this stripe
2259 * Any reads will already have been scheduled, so we just see if enough data
2260 * is available
2261 */
2262 if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) {
2263 int update_p = 0, update_q = 0;
2264 struct r5dev *dev;
2265
2266 set_bit(STRIPE_HANDLE, &sh->state);
2267
2268 BUG_ON(failed>2);
2269 BUG_ON(uptodate < disks);
2270 /* Want to check and possibly repair P and Q.
2271 * However there could be one 'failed' device, in which
2272 * case we can only check one of them, possibly using the
2273 * other to generate missing data
2274 */
2275
2276 /* If !tmp_page, we cannot do the calculations,
2277 * but as we have set STRIPE_HANDLE, we will soon be called
2278 * by stripe_handle with a tmp_page - just wait until then.
2279 */
2280 if (tmp_page) {
2281 if (failed == q_failed) {
2282 /* The only possible failed device holds 'Q', so it makes
2283 * sense to check P (If anything else were failed, we would
2284 * have used P to recreate it).
2285 */
2286 compute_block_1(sh, pd_idx, 1);
2287 if (!page_is_zero(sh->dev[pd_idx].page)) {
2288 compute_block_1(sh,pd_idx,0);
2289 update_p = 1;
2290 }
2291 }
2292 if (!q_failed && failed < 2) {
2293 /* q is not failed, and we didn't use it to generate
2294 * anything, so it makes sense to check it
2295 */
2296 memcpy(page_address(tmp_page),
2297 page_address(sh->dev[qd_idx].page),
2298 STRIPE_SIZE);
2299 compute_parity6(sh, UPDATE_PARITY);
2300 if (memcmp(page_address(tmp_page),
2301 page_address(sh->dev[qd_idx].page),
2302 STRIPE_SIZE)!= 0) {
2303 clear_bit(STRIPE_INSYNC, &sh->state);
2304 update_q = 1;
2305 }
2306 }
2307 if (update_p || update_q) {
2308 conf->mddev->resync_mismatches += STRIPE_SECTORS;
2309 if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
2310 /* don't try to repair!! */
2311 update_p = update_q = 0;
2312 }
2313
2314 /* now write out any block on a failed drive,
2315 * or P or Q if they need it
2316 */
2317
2318 if (failed == 2) {
2319 dev = &sh->dev[failed_num[1]];
2320 locked++;
2321 set_bit(R5_LOCKED, &dev->flags);
2322 set_bit(R5_Wantwrite, &dev->flags);
2323 }
2324 if (failed >= 1) {
2325 dev = &sh->dev[failed_num[0]];
2326 locked++;
2327 set_bit(R5_LOCKED, &dev->flags);
2328 set_bit(R5_Wantwrite, &dev->flags);
2329 }
2330
2331 if (update_p) {
2332 dev = &sh->dev[pd_idx];
2333 locked ++;
2334 set_bit(R5_LOCKED, &dev->flags);
2335 set_bit(R5_Wantwrite, &dev->flags);
2336 }
2337 if (update_q) {
2338 dev = &sh->dev[qd_idx];
2339 locked++;
2340 set_bit(R5_LOCKED, &dev->flags);
2341 set_bit(R5_Wantwrite, &dev->flags);
2342 }
2343 clear_bit(STRIPE_DEGRADED, &sh->state);
2344
2345 set_bit(STRIPE_INSYNC, &sh->state);
2346 }
2347 }
2348
2349 if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
2350 md_done_sync(conf->mddev, STRIPE_SECTORS,1);
2351 clear_bit(STRIPE_SYNCING, &sh->state);
2352 }
2353
2354 /* If the failed drives are just a ReadError, then we might need
2355 * to progress the repair/check process
2356 */
2357 if (failed <= 2 && ! conf->mddev->ro)
2358 for (i=0; i<failed;i++) {
2359 dev = &sh->dev[failed_num[i]];
2360 if (test_bit(R5_ReadError, &dev->flags)
2361 && !test_bit(R5_LOCKED, &dev->flags)
2362 && test_bit(R5_UPTODATE, &dev->flags)
2363 ) {
2364 if (!test_bit(R5_ReWrite, &dev->flags)) {
2365 set_bit(R5_Wantwrite, &dev->flags);
2366 set_bit(R5_ReWrite, &dev->flags);
2367 set_bit(R5_LOCKED, &dev->flags);
2368 } else {
2369 /* let's read it back */
2370 set_bit(R5_Wantread, &dev->flags);
2371 set_bit(R5_LOCKED, &dev->flags);
2372 }
2373 }
2374 }
2375 spin_unlock(&sh->lock);
2376
2377 while ((bi=return_bi)) {
2378 int bytes = bi->bi_size;
2379
2380 return_bi = bi->bi_next;
2381 bi->bi_next = NULL;
2382 bi->bi_size = 0;
2383 bi->bi_end_io(bi, bytes, 0);
2384 }
2385 for (i=disks; i-- ;) {
2386 int rw;
2387 struct bio *bi;
2388 mdk_rdev_t *rdev;
2389 if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
2390 rw = 1;
2391 else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
2392 rw = 0;
2393 else
2394 continue;
2395
2396 bi = &sh->dev[i].req;
2397
2398 bi->bi_rw = rw;
2399 if (rw)
2400 bi->bi_end_io = raid5_end_write_request;
2401 else
2402 bi->bi_end_io = raid5_end_read_request;
2403
2404 rcu_read_lock();
2405 rdev = rcu_dereference(conf->disks[i].rdev);
2406 if (rdev && test_bit(Faulty, &rdev->flags))
2407 rdev = NULL;
2408 if (rdev)
2409 atomic_inc(&rdev->nr_pending);
2410 rcu_read_unlock();
2411
2412 if (rdev) {
2413 if (syncing)
2414 md_sync_acct(rdev->bdev, STRIPE_SECTORS);
2415
2416 bi->bi_bdev = rdev->bdev;
2417 PRINTK("for %llu schedule op %ld on disc %d\n",
2418 (unsigned long long)sh->sector, bi->bi_rw, i);
2419 atomic_inc(&sh->count);
2420 bi->bi_sector = sh->sector + rdev->data_offset;
2421 bi->bi_flags = 1 << BIO_UPTODATE;
2422 bi->bi_vcnt = 1;
2423 bi->bi_max_vecs = 1;
2424 bi->bi_idx = 0;
2425 bi->bi_io_vec = &sh->dev[i].vec;
2426 bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
2427 bi->bi_io_vec[0].bv_offset = 0;
2428 bi->bi_size = STRIPE_SIZE;
2429 bi->bi_next = NULL;
2430 if (rw == WRITE &&
2431 test_bit(R5_ReWrite, &sh->dev[i].flags))
2432 atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
2433 generic_make_request(bi);
2434 } else {
2435 if (rw == 1)
2436 set_bit(STRIPE_DEGRADED, &sh->state);
2437 PRINTK("skip op %ld on disc %d for sector %llu\n",
2438 bi->bi_rw, i, (unsigned long long)sh->sector);
2439 clear_bit(R5_LOCKED, &sh->dev[i].flags);
2440 set_bit(STRIPE_HANDLE, &sh->state);
2441 }
2442 }
2443}
2444
2445static void handle_stripe(struct stripe_head *sh, struct page *tmp_page)
2446{
2447 if (sh->raid_conf->level == 6)
2448 handle_stripe6(sh, tmp_page);
2449 else
2450 handle_stripe5(sh);
2451}
2452
2453
2454
1618static void raid5_activate_delayed(raid5_conf_t *conf) 2455static void raid5_activate_delayed(raid5_conf_t *conf)
1619{ 2456{
1620 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { 2457 if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
@@ -1753,7 +2590,7 @@ static int make_request(request_queue_t *q, struct bio * bi)
1753 2590
1754 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { 2591 for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
1755 DEFINE_WAIT(w); 2592 DEFINE_WAIT(w);
1756 int disks; 2593 int disks, data_disks;
1757 2594
1758 retry: 2595 retry:
1759 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); 2596 prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
@@ -1781,7 +2618,9 @@ static int make_request(request_queue_t *q, struct bio * bi)
1781 } 2618 }
1782 spin_unlock_irq(&conf->device_lock); 2619 spin_unlock_irq(&conf->device_lock);
1783 } 2620 }
1784 new_sector = raid5_compute_sector(logical_sector, disks, disks - 1, 2621 data_disks = disks - conf->max_degraded;
2622
2623 new_sector = raid5_compute_sector(logical_sector, disks, data_disks,
1785 &dd_idx, &pd_idx, conf); 2624 &dd_idx, &pd_idx, conf);
1786 PRINTK("raid5: make_request, sector %llu logical %llu\n", 2625 PRINTK("raid5: make_request, sector %llu logical %llu\n",
1787 (unsigned long long)new_sector, 2626 (unsigned long long)new_sector,
@@ -1833,7 +2672,7 @@ static int make_request(request_queue_t *q, struct bio * bi)
1833 } 2672 }
1834 finish_wait(&conf->wait_for_overlap, &w); 2673 finish_wait(&conf->wait_for_overlap, &w);
1835 raid5_plug_device(conf); 2674 raid5_plug_device(conf);
1836 handle_stripe(sh); 2675 handle_stripe(sh, NULL);
1837 release_stripe(sh); 2676 release_stripe(sh);
1838 } else { 2677 } else {
1839 /* cannot get stripe for read-ahead, just give-up */ 2678 /* cannot get stripe for read-ahead, just give-up */
@@ -1849,7 +2688,7 @@ static int make_request(request_queue_t *q, struct bio * bi)
1849 if (remaining == 0) { 2688 if (remaining == 0) {
1850 int bytes = bi->bi_size; 2689 int bytes = bi->bi_size;
1851 2690
1852 if ( bio_data_dir(bi) == WRITE ) 2691 if ( rw == WRITE )
1853 md_write_end(mddev); 2692 md_write_end(mddev);
1854 bi->bi_size = 0; 2693 bi->bi_size = 0;
1855 bi->bi_end_io(bi, bytes, 0); 2694 bi->bi_end_io(bi, bytes, 0);
@@ -1865,9 +2704,11 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
1865 int pd_idx; 2704 int pd_idx;
1866 sector_t first_sector, last_sector; 2705 sector_t first_sector, last_sector;
1867 int raid_disks = conf->raid_disks; 2706 int raid_disks = conf->raid_disks;
1868 int data_disks = raid_disks-1; 2707 int data_disks = raid_disks - conf->max_degraded;
1869 sector_t max_sector = mddev->size << 1; 2708 sector_t max_sector = mddev->size << 1;
1870 int sync_blocks; 2709 int sync_blocks;
2710 int still_degraded = 0;
2711 int i;
1871 2712
1872 if (sector_nr >= max_sector) { 2713 if (sector_nr >= max_sector) {
1873 /* just being told to finish up .. nothing much to do */ 2714 /* just being told to finish up .. nothing much to do */
@@ -1880,7 +2721,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
1880 if (mddev->curr_resync < max_sector) /* aborted */ 2721 if (mddev->curr_resync < max_sector) /* aborted */
1881 bitmap_end_sync(mddev->bitmap, mddev->curr_resync, 2722 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1882 &sync_blocks, 1); 2723 &sync_blocks, 1);
1883 else /* compelted sync */ 2724 else /* completed sync */
1884 conf->fullsync = 0; 2725 conf->fullsync = 0;
1885 bitmap_close_sync(mddev->bitmap); 2726 bitmap_close_sync(mddev->bitmap);
1886 2727
@@ -2003,11 +2844,12 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
2003 } 2844 }
2004 return conf->chunk_size>>9; 2845 return conf->chunk_size>>9;
2005 } 2846 }
2006 /* if there is 1 or more failed drives and we are trying 2847 /* if there is too many failed drives and we are trying
2007 * to resync, then assert that we are finished, because there is 2848 * to resync, then assert that we are finished, because there is
2008 * nothing we can do. 2849 * nothing we can do.
2009 */ 2850 */
2010 if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { 2851 if (mddev->degraded >= (data_disks - raid_disks) &&
2852 test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2011 sector_t rv = (mddev->size << 1) - sector_nr; 2853 sector_t rv = (mddev->size << 1) - sector_nr;
2012 *skipped = 1; 2854 *skipped = 1;
2013 return rv; 2855 return rv;
@@ -2026,17 +2868,26 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
2026 if (sh == NULL) { 2868 if (sh == NULL) {
2027 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0); 2869 sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0);
2028 /* make sure we don't swamp the stripe cache if someone else 2870 /* make sure we don't swamp the stripe cache if someone else
2029 * is trying to get access 2871 * is trying to get access
2030 */ 2872 */
2031 schedule_timeout_uninterruptible(1); 2873 schedule_timeout_uninterruptible(1);
2032 } 2874 }
2033 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0); 2875 /* Need to check if array will still be degraded after recovery/resync
2034 spin_lock(&sh->lock); 2876 * We don't need to check the 'failed' flag as when that gets set,
2877 * recovery aborts.
2878 */
2879 for (i=0; i<mddev->raid_disks; i++)
2880 if (conf->disks[i].rdev == NULL)
2881 still_degraded = 1;
2882
2883 bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
2884
2885 spin_lock(&sh->lock);
2035 set_bit(STRIPE_SYNCING, &sh->state); 2886 set_bit(STRIPE_SYNCING, &sh->state);
2036 clear_bit(STRIPE_INSYNC, &sh->state); 2887 clear_bit(STRIPE_INSYNC, &sh->state);
2037 spin_unlock(&sh->lock); 2888 spin_unlock(&sh->lock);
2038 2889
2039 handle_stripe(sh); 2890 handle_stripe(sh, NULL);
2040 release_stripe(sh); 2891 release_stripe(sh);
2041 2892
2042 return STRIPE_SECTORS; 2893 return STRIPE_SECTORS;
@@ -2091,7 +2942,7 @@ static void raid5d (mddev_t *mddev)
2091 spin_unlock_irq(&conf->device_lock); 2942 spin_unlock_irq(&conf->device_lock);
2092 2943
2093 handled++; 2944 handled++;
2094 handle_stripe(sh); 2945 handle_stripe(sh, conf->spare_page);
2095 release_stripe(sh); 2946 release_stripe(sh);
2096 2947
2097 spin_lock_irq(&conf->device_lock); 2948 spin_lock_irq(&conf->device_lock);
@@ -2181,8 +3032,8 @@ static int run(mddev_t *mddev)
2181 struct disk_info *disk; 3032 struct disk_info *disk;
2182 struct list_head *tmp; 3033 struct list_head *tmp;
2183 3034
2184 if (mddev->level != 5 && mddev->level != 4) { 3035 if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
2185 printk(KERN_ERR "raid5: %s: raid level not set to 4/5 (%d)\n", 3036 printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
2186 mdname(mddev), mddev->level); 3037 mdname(mddev), mddev->level);
2187 return -EIO; 3038 return -EIO;
2188 } 3039 }
@@ -2251,6 +3102,11 @@ static int run(mddev_t *mddev)
2251 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL) 3102 if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
2252 goto abort; 3103 goto abort;
2253 3104
3105 if (mddev->level == 6) {
3106 conf->spare_page = alloc_page(GFP_KERNEL);
3107 if (!conf->spare_page)
3108 goto abort;
3109 }
2254 spin_lock_init(&conf->device_lock); 3110 spin_lock_init(&conf->device_lock);
2255 init_waitqueue_head(&conf->wait_for_stripe); 3111 init_waitqueue_head(&conf->wait_for_stripe);
2256 init_waitqueue_head(&conf->wait_for_overlap); 3112 init_waitqueue_head(&conf->wait_for_overlap);
@@ -2282,12 +3138,16 @@ static int run(mddev_t *mddev)
2282 } 3138 }
2283 3139
2284 /* 3140 /*
2285 * 0 for a fully functional array, 1 for a degraded array. 3141 * 0 for a fully functional array, 1 or 2 for a degraded array.
2286 */ 3142 */
2287 mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks; 3143 mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks;
2288 conf->mddev = mddev; 3144 conf->mddev = mddev;
2289 conf->chunk_size = mddev->chunk_size; 3145 conf->chunk_size = mddev->chunk_size;
2290 conf->level = mddev->level; 3146 conf->level = mddev->level;
3147 if (conf->level == 6)
3148 conf->max_degraded = 2;
3149 else
3150 conf->max_degraded = 1;
2291 conf->algorithm = mddev->layout; 3151 conf->algorithm = mddev->layout;
2292 conf->max_nr_stripes = NR_STRIPES; 3152 conf->max_nr_stripes = NR_STRIPES;
2293 conf->expand_progress = mddev->reshape_position; 3153 conf->expand_progress = mddev->reshape_position;
@@ -2296,6 +3156,11 @@ static int run(mddev_t *mddev)
2296 mddev->size &= ~(mddev->chunk_size/1024 -1); 3156 mddev->size &= ~(mddev->chunk_size/1024 -1);
2297 mddev->resync_max_sectors = mddev->size << 1; 3157 mddev->resync_max_sectors = mddev->size << 1;
2298 3158
3159 if (conf->level == 6 && conf->raid_disks < 4) {
3160 printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
3161 mdname(mddev), conf->raid_disks);
3162 goto abort;
3163 }
2299 if (!conf->chunk_size || conf->chunk_size % 4) { 3164 if (!conf->chunk_size || conf->chunk_size % 4) {
2300 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n", 3165 printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
2301 conf->chunk_size, mdname(mddev)); 3166 conf->chunk_size, mdname(mddev));
@@ -2307,14 +3172,14 @@ static int run(mddev_t *mddev)
2307 conf->algorithm, mdname(mddev)); 3172 conf->algorithm, mdname(mddev));
2308 goto abort; 3173 goto abort;
2309 } 3174 }
2310 if (mddev->degraded > 1) { 3175 if (mddev->degraded > conf->max_degraded) {
2311 printk(KERN_ERR "raid5: not enough operational devices for %s" 3176 printk(KERN_ERR "raid5: not enough operational devices for %s"
2312 " (%d/%d failed)\n", 3177 " (%d/%d failed)\n",
2313 mdname(mddev), conf->failed_disks, conf->raid_disks); 3178 mdname(mddev), conf->failed_disks, conf->raid_disks);
2314 goto abort; 3179 goto abort;
2315 } 3180 }
2316 3181
2317 if (mddev->degraded == 1 && 3182 if (mddev->degraded > 0 &&
2318 mddev->recovery_cp != MaxSector) { 3183 mddev->recovery_cp != MaxSector) {
2319 if (mddev->ok_start_degraded) 3184 if (mddev->ok_start_degraded)
2320 printk(KERN_WARNING 3185 printk(KERN_WARNING
@@ -2379,10 +3244,11 @@ static int run(mddev_t *mddev)
2379 } 3244 }
2380 3245
2381 /* read-ahead size must cover two whole stripes, which is 3246 /* read-ahead size must cover two whole stripes, which is
2382 * 2 * (n-1) * chunksize where 'n' is the number of raid devices 3247 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
2383 */ 3248 */
2384 { 3249 {
2385 int stripe = (mddev->raid_disks-1) * 3250 int data_disks = conf->previous_raid_disks - conf->max_degraded;
3251 int stripe = data_disks *
2386 (mddev->chunk_size / PAGE_SIZE); 3252 (mddev->chunk_size / PAGE_SIZE);
2387 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) 3253 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
2388 mddev->queue->backing_dev_info.ra_pages = 2 * stripe; 3254 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
@@ -2393,12 +3259,14 @@ static int run(mddev_t *mddev)
2393 3259
2394 mddev->queue->unplug_fn = raid5_unplug_device; 3260 mddev->queue->unplug_fn = raid5_unplug_device;
2395 mddev->queue->issue_flush_fn = raid5_issue_flush; 3261 mddev->queue->issue_flush_fn = raid5_issue_flush;
2396 mddev->array_size = mddev->size * (conf->previous_raid_disks - 1); 3262 mddev->array_size = mddev->size * (conf->previous_raid_disks -
3263 conf->max_degraded);
2397 3264
2398 return 0; 3265 return 0;
2399abort: 3266abort:
2400 if (conf) { 3267 if (conf) {
2401 print_raid5_conf(conf); 3268 print_raid5_conf(conf);
3269 safe_put_page(conf->spare_page);
2402 kfree(conf->disks); 3270 kfree(conf->disks);
2403 kfree(conf->stripe_hashtbl); 3271 kfree(conf->stripe_hashtbl);
2404 kfree(conf); 3272 kfree(conf);
@@ -2427,23 +3295,23 @@ static int stop(mddev_t *mddev)
2427} 3295}
2428 3296
2429#if RAID5_DEBUG 3297#if RAID5_DEBUG
2430static void print_sh (struct stripe_head *sh) 3298static void print_sh (struct seq_file *seq, struct stripe_head *sh)
2431{ 3299{
2432 int i; 3300 int i;
2433 3301
2434 printk("sh %llu, pd_idx %d, state %ld.\n", 3302 seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
2435 (unsigned long long)sh->sector, sh->pd_idx, sh->state); 3303 (unsigned long long)sh->sector, sh->pd_idx, sh->state);
2436 printk("sh %llu, count %d.\n", 3304 seq_printf(seq, "sh %llu, count %d.\n",
2437 (unsigned long long)sh->sector, atomic_read(&sh->count)); 3305 (unsigned long long)sh->sector, atomic_read(&sh->count));
2438 printk("sh %llu, ", (unsigned long long)sh->sector); 3306 seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
2439 for (i = 0; i < sh->disks; i++) { 3307 for (i = 0; i < sh->disks; i++) {
2440 printk("(cache%d: %p %ld) ", 3308 seq_printf(seq, "(cache%d: %p %ld) ",
2441 i, sh->dev[i].page, sh->dev[i].flags); 3309 i, sh->dev[i].page, sh->dev[i].flags);
2442 } 3310 }
2443 printk("\n"); 3311 seq_printf(seq, "\n");
2444} 3312}
2445 3313
2446static void printall (raid5_conf_t *conf) 3314static void printall (struct seq_file *seq, raid5_conf_t *conf)
2447{ 3315{
2448 struct stripe_head *sh; 3316 struct stripe_head *sh;
2449 struct hlist_node *hn; 3317 struct hlist_node *hn;
@@ -2454,7 +3322,7 @@ static void printall (raid5_conf_t *conf)
2454 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) { 3322 hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
2455 if (sh->raid_conf != conf) 3323 if (sh->raid_conf != conf)
2456 continue; 3324 continue;
2457 print_sh(sh); 3325 print_sh(seq, sh);
2458 } 3326 }
2459 } 3327 }
2460 spin_unlock_irq(&conf->device_lock); 3328 spin_unlock_irq(&conf->device_lock);
@@ -2474,9 +3342,8 @@ static void status (struct seq_file *seq, mddev_t *mddev)
2474 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); 3342 test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
2475 seq_printf (seq, "]"); 3343 seq_printf (seq, "]");
2476#if RAID5_DEBUG 3344#if RAID5_DEBUG
2477#define D(x) \ 3345 seq_printf (seq, "\n");
2478 seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x)) 3346 printall(seq, conf);
2479 printall(conf);
2480#endif 3347#endif
2481} 3348}
2482 3349
@@ -2560,14 +3427,20 @@ static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
2560 int disk; 3427 int disk;
2561 struct disk_info *p; 3428 struct disk_info *p;
2562 3429
2563 if (mddev->degraded > 1) 3430 if (mddev->degraded > conf->max_degraded)
2564 /* no point adding a device */ 3431 /* no point adding a device */
2565 return 0; 3432 return 0;
2566 3433
2567 /* 3434 /*
2568 * find the disk ... 3435 * find the disk ... but prefer rdev->saved_raid_disk
3436 * if possible.
2569 */ 3437 */
2570 for (disk=0; disk < conf->raid_disks; disk++) 3438 if (rdev->saved_raid_disk >= 0 &&
3439 conf->disks[rdev->saved_raid_disk].rdev == NULL)
3440 disk = rdev->saved_raid_disk;
3441 else
3442 disk = 0;
3443 for ( ; disk < conf->raid_disks; disk++)
2571 if ((p=conf->disks + disk)->rdev == NULL) { 3444 if ((p=conf->disks + disk)->rdev == NULL) {
2572 clear_bit(In_sync, &rdev->flags); 3445 clear_bit(In_sync, &rdev->flags);
2573 rdev->raid_disk = disk; 3446 rdev->raid_disk = disk;
@@ -2590,8 +3463,10 @@ static int raid5_resize(mddev_t *mddev, sector_t sectors)
2590 * any io in the removed space completes, but it hardly seems 3463 * any io in the removed space completes, but it hardly seems
2591 * worth it. 3464 * worth it.
2592 */ 3465 */
3466 raid5_conf_t *conf = mddev_to_conf(mddev);
3467
2593 sectors &= ~((sector_t)mddev->chunk_size/512 - 1); 3468 sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
2594 mddev->array_size = (sectors * (mddev->raid_disks-1))>>1; 3469 mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1;
2595 set_capacity(mddev->gendisk, mddev->array_size << 1); 3470 set_capacity(mddev->gendisk, mddev->array_size << 1);
2596 mddev->changed = 1; 3471 mddev->changed = 1;
2597 if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) { 3472 if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
@@ -2731,6 +3606,17 @@ static void end_reshape(raid5_conf_t *conf)
2731 conf->expand_progress = MaxSector; 3606 conf->expand_progress = MaxSector;
2732 spin_unlock_irq(&conf->device_lock); 3607 spin_unlock_irq(&conf->device_lock);
2733 conf->mddev->reshape_position = MaxSector; 3608 conf->mddev->reshape_position = MaxSector;
3609
3610 /* read-ahead size must cover two whole stripes, which is
3611 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
3612 */
3613 {
3614 int data_disks = conf->previous_raid_disks - conf->max_degraded;
3615 int stripe = data_disks *
3616 (conf->mddev->chunk_size / PAGE_SIZE);
3617 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
3618 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
3619 }
2734 } 3620 }
2735} 3621}
2736 3622
@@ -2762,6 +3648,23 @@ static void raid5_quiesce(mddev_t *mddev, int state)
2762 } 3648 }
2763} 3649}
2764 3650
3651static struct mdk_personality raid6_personality =
3652{
3653 .name = "raid6",
3654 .level = 6,
3655 .owner = THIS_MODULE,
3656 .make_request = make_request,
3657 .run = run,
3658 .stop = stop,
3659 .status = status,
3660 .error_handler = error,
3661 .hot_add_disk = raid5_add_disk,
3662 .hot_remove_disk= raid5_remove_disk,
3663 .spare_active = raid5_spare_active,
3664 .sync_request = sync_request,
3665 .resize = raid5_resize,
3666 .quiesce = raid5_quiesce,
3667};
2765static struct mdk_personality raid5_personality = 3668static struct mdk_personality raid5_personality =
2766{ 3669{
2767 .name = "raid5", 3670 .name = "raid5",
@@ -2804,6 +3707,12 @@ static struct mdk_personality raid4_personality =
2804 3707
2805static int __init raid5_init(void) 3708static int __init raid5_init(void)
2806{ 3709{
3710 int e;
3711
3712 e = raid6_select_algo();
3713 if ( e )
3714 return e;
3715 register_md_personality(&raid6_personality);
2807 register_md_personality(&raid5_personality); 3716 register_md_personality(&raid5_personality);
2808 register_md_personality(&raid4_personality); 3717 register_md_personality(&raid4_personality);
2809 return 0; 3718 return 0;
@@ -2811,6 +3720,7 @@ static int __init raid5_init(void)
2811 3720
2812static void raid5_exit(void) 3721static void raid5_exit(void)
2813{ 3722{
3723 unregister_md_personality(&raid6_personality);
2814 unregister_md_personality(&raid5_personality); 3724 unregister_md_personality(&raid5_personality);
2815 unregister_md_personality(&raid4_personality); 3725 unregister_md_personality(&raid4_personality);
2816} 3726}
@@ -2823,3 +3733,10 @@ MODULE_ALIAS("md-raid5");
2823MODULE_ALIAS("md-raid4"); 3733MODULE_ALIAS("md-raid4");
2824MODULE_ALIAS("md-level-5"); 3734MODULE_ALIAS("md-level-5");
2825MODULE_ALIAS("md-level-4"); 3735MODULE_ALIAS("md-level-4");
3736MODULE_ALIAS("md-personality-8"); /* RAID6 */
3737MODULE_ALIAS("md-raid6");
3738MODULE_ALIAS("md-level-6");
3739
3740/* This used to be two separate modules, they were: */
3741MODULE_ALIAS("raid5");
3742MODULE_ALIAS("raid6");
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-30 04:33:04 -0400