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 }; 22 23 struct r10conf { 24 struct mddev *mddev; 25 struct raid10_info *mirrors; 26 struct raid10_info *mirrors_new, *mirrors_old; 27 spinlock_t device_lock; 28 29 /* geometry */ 30 struct geom { 31 int raid_disks; 32 int near_copies; /* number of copies laid out 33 * raid0 style */ 34 int far_copies; /* number of copies laid out 35 * at large strides across drives 36 */ 37 int far_offset; /* far_copies are offset by 1 38 * stripe instead of many 39 */ 40 sector_t stride; /* distance between far copies. 41 * This is size / far_copies unless 42 * far_offset, in which case it is 43 * 1 stripe. 44 */ 45 int far_set_size; /* The number of devices in a set, 46 * where a 'set' are devices that 47 * contain far/offset copies of 48 * each other. 49 */ 50 int chunk_shift; /* shift from chunks to sectors */ 51 sector_t chunk_mask; 52 } prev, geo; 53 int copies; /* near_copies * far_copies. 54 * must be <= raid_disks 55 */ 56 57 sector_t dev_sectors; /* temp copy of 58 * mddev->dev_sectors */ 59 sector_t reshape_progress; 60 sector_t reshape_safe; 61 unsigned long reshape_checkpoint; 62 sector_t offset_diff; 63 64 struct list_head retry_list; 65 /* A separate list of r1bio which just need raid_end_bio_io called. 66 * This mustn't happen for writes which had any errors if the superblock 67 * needs to be written. 68 */ 69 struct list_head bio_end_io_list; 70 71 /* queue pending writes and submit them on unplug */ 72 struct bio_list pending_bio_list; 73 74 seqlock_t resync_lock; 75 atomic_t nr_pending; 76 int nr_waiting; 77 int nr_queued; 78 int barrier; 79 int array_freeze_pending; 80 sector_t next_resync; 81 int fullsync; /* set to 1 if a full sync is needed, 82 * (fresh device added). 83 * Cleared when a sync completes. 84 */ 85 int have_replacement; /* There is at least one 86 * replacement device. 87 */ 88 wait_queue_head_t wait_barrier; 89 90 mempool_t r10bio_pool; 91 mempool_t r10buf_pool; 92 struct page *tmppage; 93 struct bio_set bio_split; 94 95 /* When taking over an array from a different personality, we store 96 * the new thread here until we fully activate the array. 97 */ 98 struct md_thread __rcu *thread; 99 100 /* 101 * Keep track of cluster resync window to send to other nodes. 102 */ 103 sector_t cluster_sync_low; 104 sector_t cluster_sync_high; 105 }; 106 107 /* 108 * this is our 'private' RAID10 bio. 109 * 110 * it contains information about what kind of IO operations were started 111 * for this RAID10 operation, and about their status: 112 */ 113 114 struct r10bio { 115 atomic_t remaining; /* 'have we finished' count, 116 * used from IRQ handlers 117 */ 118 sector_t sector; /* virtual sector number */ 119 int sectors; 120 unsigned long state; 121 struct mddev *mddev; 122 /* 123 * original bio going to /dev/mdx 124 */ 125 struct bio *master_bio; 126 /* 127 * if the IO is in READ direction, then this is where we read 128 */ 129 int read_slot; 130 131 struct list_head retry_list; 132 /* 133 * if the IO is in WRITE direction, then multiple bios are used, 134 * one for each copy. 135 * When resyncing we also use one for each copy. 136 * When reconstructing, we use 2 bios, one for read, one for write. 137 * We choose the number when they are allocated. 138 * We sometimes need an extra bio to write to the replacement. 139 */ 140 struct r10dev { 141 struct bio *bio; 142 union { 143 struct bio *repl_bio; /* used for resync and 144 * writes */ 145 struct md_rdev *rdev; /* used for reads 146 * (read_slot >= 0) */ 147 }; 148 sector_t addr; 149 int devnum; 150 } devs[]; 151 }; 152 153 /* bits for r10bio.state */ 154 enum r10bio_state { 155 R10BIO_Uptodate, 156 R10BIO_IsSync, 157 R10BIO_IsRecover, 158 R10BIO_IsReshape, 159 /* Set ReadError on bios that experience a read error 160 * so that raid10d knows what to do with them. 161 */ 162 R10BIO_ReadError, 163 /* For bio_split errors, record that bi_end_io was called. */ 164 R10BIO_Returned, 165 /* If a write for this request means we can clear some 166 * known-bad-block records, we set this flag. 167 */ 168 R10BIO_MadeGood, 169 R10BIO_WriteError, 170 /* During a reshape we might be performing IO on the 171 * 'previous' part of the array, in which case this 172 * flag is set 173 */ 174 R10BIO_Previous, 175 /* failfast devices did receive failfast requests. */ 176 R10BIO_FailFast, 177 R10BIO_Discard, 178 }; 179 #endif 180