1 #ifndef _RAID10_H 2 #define _RAID10_H 3 4 struct mirror_info { 5 struct md_rdev *rdev, *replacement; 6 sector_t head_position; 7 int recovery_disabled; /* matches 8 * mddev->recovery_disabled 9 * when we shouldn't try 10 * recovering this device. 11 */ 12 }; 13 14 struct r10conf { 15 struct mddev *mddev; 16 struct mirror_info *mirrors; 17 int raid_disks; 18 spinlock_t device_lock; 19 20 /* geometry */ 21 int near_copies; /* number of copies laid out 22 * raid0 style */ 23 int far_copies; /* number of copies laid out 24 * at large strides across drives 25 */ 26 int far_offset; /* far_copies are offset by 1 27 * stripe instead of many 28 */ 29 int copies; /* near_copies * far_copies. 30 * must be <= raid_disks 31 */ 32 sector_t stride; /* distance between far copies. 33 * This is size / far_copies unless 34 * far_offset, in which case it is 35 * 1 stripe. 36 */ 37 38 sector_t dev_sectors; /* temp copy of 39 * mddev->dev_sectors */ 40 41 int chunk_shift; /* shift from chunks to sectors */ 42 sector_t chunk_mask; 43 44 struct list_head retry_list; 45 /* queue pending writes and submit them on unplug */ 46 struct bio_list pending_bio_list; 47 int pending_count; 48 49 spinlock_t resync_lock; 50 int nr_pending; 51 int nr_waiting; 52 int nr_queued; 53 int barrier; 54 sector_t next_resync; 55 int fullsync; /* set to 1 if a full sync is needed, 56 * (fresh device added). 57 * Cleared when a sync completes. 58 */ 59 int have_replacement; /* There is at least one 60 * replacement device. 61 */ 62 wait_queue_head_t wait_barrier; 63 64 mempool_t *r10bio_pool; 65 mempool_t *r10buf_pool; 66 struct page *tmppage; 67 68 /* When taking over an array from a different personality, we store 69 * the new thread here until we fully activate the array. 70 */ 71 struct md_thread *thread; 72 }; 73 74 /* 75 * this is our 'private' RAID10 bio. 76 * 77 * it contains information about what kind of IO operations were started 78 * for this RAID10 operation, and about their status: 79 */ 80 81 struct r10bio { 82 atomic_t remaining; /* 'have we finished' count, 83 * used from IRQ handlers 84 */ 85 sector_t sector; /* virtual sector number */ 86 int sectors; 87 unsigned long state; 88 struct mddev *mddev; 89 /* 90 * original bio going to /dev/mdx 91 */ 92 struct bio *master_bio; 93 /* 94 * if the IO is in READ direction, then this is where we read 95 */ 96 int read_slot; 97 98 struct list_head retry_list; 99 /* 100 * if the IO is in WRITE direction, then multiple bios are used, 101 * one for each copy. 102 * When resyncing we also use one for each copy. 103 * When reconstructing, we use 2 bios, one for read, one for write. 104 * We choose the number when they are allocated. 105 * We sometimes need an extra bio to write to the replacement. 106 */ 107 struct r10dev { 108 struct bio *bio; 109 union { 110 struct bio *repl_bio; /* used for resync and 111 * writes */ 112 struct md_rdev *rdev; /* used for reads 113 * (read_slot >= 0) */ 114 }; 115 sector_t addr; 116 int devnum; 117 } devs[0]; 118 }; 119 120 /* when we get a read error on a read-only array, we redirect to another 121 * device without failing the first device, or trying to over-write to 122 * correct the read error. To keep track of bad blocks on a per-bio 123 * level, we store IO_BLOCKED in the appropriate 'bios' pointer 124 */ 125 #define IO_BLOCKED ((struct bio*)1) 126 /* When we successfully write to a known bad-block, we need to remove the 127 * bad-block marking which must be done from process context. So we record 128 * the success by setting devs[n].bio to IO_MADE_GOOD 129 */ 130 #define IO_MADE_GOOD ((struct bio *)2) 131 132 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2) 133 134 /* bits for r10bio.state */ 135 enum r10bio_state { 136 R10BIO_Uptodate, 137 R10BIO_IsSync, 138 R10BIO_IsRecover, 139 R10BIO_Degraded, 140 /* Set ReadError on bios that experience a read error 141 * so that raid10d knows what to do with them. 142 */ 143 R10BIO_ReadError, 144 /* If a write for this request means we can clear some 145 * known-bad-block records, we set this flag. 146 */ 147 R10BIO_MadeGood, 148 R10BIO_WriteError, 149 }; 150 #endif 151