1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _RAID10_H 3 #define _RAID10_H 4 5 /* Note: raid10_info.rdev can be set to NULL asynchronously by 6 * raid10_remove_disk. 7 * There are three safe ways to access raid10_info.rdev. 8 * 1/ when holding mddev->reconfig_mutex 9 * 2/ when resync/recovery/reshape is known to be happening - i.e. in code 10 * that is called as part of performing resync/recovery/reshape. 11 * 3/ while holding rcu_read_lock(), use rcu_dereference to get the pointer 12 * and if it is non-NULL, increment rdev->nr_pending before dropping the 13 * RCU lock. 14 * When .rdev is set to NULL, the nr_pending count checked again and if it has 15 * been incremented, the pointer is put back in .rdev. 16 */ 17 18 struct raid10_info { 19 struct md_rdev *rdev, *replacement; 20 sector_t head_position; 21 int recovery_disabled; /* matches 22 * mddev->recovery_disabled 23 * when we shouldn't try 24 * recovering this device. 25 */ 26 }; 27 28 struct r10conf { 29 struct mddev *mddev; 30 struct raid10_info *mirrors; 31 struct raid10_info *mirrors_new, *mirrors_old; 32 spinlock_t device_lock; 33 34 /* geometry */ 35 struct geom { 36 int raid_disks; 37 int near_copies; /* number of copies laid out 38 * raid0 style */ 39 int far_copies; /* number of copies laid out 40 * at large strides across drives 41 */ 42 int far_offset; /* far_copies are offset by 1 43 * stripe instead of many 44 */ 45 sector_t stride; /* distance between far copies. 46 * This is size / far_copies unless 47 * far_offset, in which case it is 48 * 1 stripe. 49 */ 50 int far_set_size; /* The number of devices in a set, 51 * where a 'set' are devices that 52 * contain far/offset copies of 53 * each other. 54 */ 55 int chunk_shift; /* shift from chunks to sectors */ 56 sector_t chunk_mask; 57 } prev, geo; 58 int copies; /* near_copies * far_copies. 59 * must be <= raid_disks 60 */ 61 62 sector_t dev_sectors; /* temp copy of 63 * mddev->dev_sectors */ 64 sector_t reshape_progress; 65 sector_t reshape_safe; 66 unsigned long reshape_checkpoint; 67 sector_t offset_diff; 68 69 struct list_head retry_list; 70 /* A separate list of r1bio which just need raid_end_bio_io called. 71 * This mustn't happen for writes which had any errors if the superblock 72 * needs to be written. 73 */ 74 struct list_head bio_end_io_list; 75 76 /* queue pending writes and submit them on unplug */ 77 struct bio_list pending_bio_list; 78 79 seqlock_t resync_lock; 80 atomic_t nr_pending; 81 int nr_waiting; 82 int nr_queued; 83 int barrier; 84 int array_freeze_pending; 85 sector_t next_resync; 86 int fullsync; /* set to 1 if a full sync is needed, 87 * (fresh device added). 88 * Cleared when a sync completes. 89 */ 90 int have_replacement; /* There is at least one 91 * replacement device. 92 */ 93 wait_queue_head_t wait_barrier; 94 95 mempool_t r10bio_pool; 96 mempool_t r10buf_pool; 97 struct page *tmppage; 98 struct bio_set bio_split; 99 100 /* When taking over an array from a different personality, we store 101 * the new thread here until we fully activate the array. 102 */ 103 struct md_thread __rcu *thread; 104 105 /* 106 * Keep track of cluster resync window to send to other nodes. 107 */ 108 sector_t cluster_sync_low; 109 sector_t cluster_sync_high; 110 }; 111 112 /* 113 * this is our 'private' RAID10 bio. 114 * 115 * it contains information about what kind of IO operations were started 116 * for this RAID10 operation, and about their status: 117 */ 118 119 struct r10bio { 120 atomic_t remaining; /* 'have we finished' count, 121 * used from IRQ handlers 122 */ 123 sector_t sector; /* virtual sector number */ 124 int sectors; 125 unsigned long state; 126 struct mddev *mddev; 127 /* 128 * original bio going to /dev/mdx 129 */ 130 struct bio *master_bio; 131 /* 132 * if the IO is in READ direction, then this is where we read 133 */ 134 int read_slot; 135 136 struct list_head retry_list; 137 /* 138 * if the IO is in WRITE direction, then multiple bios are used, 139 * one for each copy. 140 * When resyncing we also use one for each copy. 141 * When reconstructing, we use 2 bios, one for read, one for write. 142 * We choose the number when they are allocated. 143 * We sometimes need an extra bio to write to the replacement. 144 */ 145 struct r10dev { 146 struct bio *bio; 147 union { 148 struct bio *repl_bio; /* used for resync and 149 * writes */ 150 struct md_rdev *rdev; /* used for reads 151 * (read_slot >= 0) */ 152 }; 153 sector_t addr; 154 int devnum; 155 } devs[]; 156 }; 157 158 /* bits for r10bio.state */ 159 enum r10bio_state { 160 R10BIO_Uptodate, 161 R10BIO_IsSync, 162 R10BIO_IsRecover, 163 R10BIO_IsReshape, 164 R10BIO_Degraded, 165 /* Set ReadError on bios that experience a read error 166 * so that raid10d knows what to do with them. 167 */ 168 R10BIO_ReadError, 169 /* If a write for this request means we can clear some 170 * known-bad-block records, we set this flag. 171 */ 172 R10BIO_MadeGood, 173 R10BIO_WriteError, 174 /* During a reshape we might be performing IO on the 175 * 'previous' part of the array, in which case this 176 * flag is set 177 */ 178 R10BIO_Previous, 179 /* failfast devices did receive failfast requests. */ 180 R10BIO_FailFast, 181 R10BIO_Discard, 182 }; 183 #endif 184