1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
2ef740c37SChristoph Hellwig #ifndef _RAID1_H
3ef740c37SChristoph Hellwig #define _RAID1_H
4ef740c37SChristoph Hellwig
5fd76863eScolyli@suse.de /*
6fd76863eScolyli@suse.de * each barrier unit size is 64MB fow now
7fd76863eScolyli@suse.de * note: it must be larger than RESYNC_DEPTH
8fd76863eScolyli@suse.de */
9fd76863eScolyli@suse.de #define BARRIER_UNIT_SECTOR_BITS 17
10fd76863eScolyli@suse.de #define BARRIER_UNIT_SECTOR_SIZE (1<<17)
11fd76863eScolyli@suse.de /*
12fd76863eScolyli@suse.de * In struct r1conf, the following members are related to I/O barrier
13fd76863eScolyli@suse.de * buckets,
14824e47daScolyli@suse.de * atomic_t *nr_pending;
15824e47daScolyli@suse.de * atomic_t *nr_waiting;
16824e47daScolyli@suse.de * atomic_t *nr_queued;
17824e47daScolyli@suse.de * atomic_t *barrier;
18824e47daScolyli@suse.de * Each of them points to array of atomic_t variables, each array is
19824e47daScolyli@suse.de * designed to have BARRIER_BUCKETS_NR elements and occupy a single
20824e47daScolyli@suse.de * memory page. The data width of atomic_t variables is 4 bytes, equal
21824e47daScolyli@suse.de * to 1<<(ilog2(sizeof(atomic_t))), BARRIER_BUCKETS_NR_BITS is defined
22824e47daScolyli@suse.de * as (PAGE_SHIFT - ilog2(sizeof(int))) to make sure an array of
23824e47daScolyli@suse.de * atomic_t variables with BARRIER_BUCKETS_NR elements just exactly
24824e47daScolyli@suse.de * occupies a single memory page.
25fd76863eScolyli@suse.de */
26824e47daScolyli@suse.de #define BARRIER_BUCKETS_NR_BITS (PAGE_SHIFT - ilog2(sizeof(atomic_t)))
27fd76863eScolyli@suse.de #define BARRIER_BUCKETS_NR (1<<BARRIER_BUCKETS_NR_BITS)
28fd76863eScolyli@suse.de
29f2785b52SNeilBrown /* Note: raid1_info.rdev can be set to NULL asynchronously by raid1_remove_disk.
30f2785b52SNeilBrown * There are three safe ways to access raid1_info.rdev.
31f2785b52SNeilBrown * 1/ when holding mddev->reconfig_mutex
32f2785b52SNeilBrown * 2/ when resync/recovery is known to be happening - i.e. in code that is
33f2785b52SNeilBrown * called as part of performing resync/recovery.
34f2785b52SNeilBrown * 3/ while holding rcu_read_lock(), use rcu_dereference to get the pointer
35f2785b52SNeilBrown * and if it is non-NULL, increment rdev->nr_pending before dropping the
36f2785b52SNeilBrown * RCU lock.
37f2785b52SNeilBrown * When .rdev is set to NULL, the nr_pending count checked again and if it has
38f2785b52SNeilBrown * been incremented, the pointer is put back in .rdev.
39f2785b52SNeilBrown */
40f2785b52SNeilBrown
410eaf822cSJonathan Brassow struct raid1_info {
423cb03002SNeilBrown struct md_rdev *rdev;
43ef740c37SChristoph Hellwig sector_t head_position;
44be4d3280SShaohua Li
45be4d3280SShaohua Li /* When choose the best device for a read (read_balance())
46be4d3280SShaohua Li * we try to keep sequential reads one the same device
47be4d3280SShaohua Li */
48be4d3280SShaohua Li sector_t next_seq_sect;
4912cee5a8SShaohua Li sector_t seq_start;
50ef740c37SChristoph Hellwig };
51ef740c37SChristoph Hellwig
52ef740c37SChristoph Hellwig /*
53ef740c37SChristoph Hellwig * memory pools need a pointer to the mddev, so they can force an unplug
54ef740c37SChristoph Hellwig * when memory is tight, and a count of the number of drives that the
55ef740c37SChristoph Hellwig * pool was allocated for, so they know how much to allocate and free.
56ef740c37SChristoph Hellwig * mddev->raid_disks cannot be used, as it can change while a pool is active
57ef740c37SChristoph Hellwig * These two datums are stored in a kmalloced struct.
588f19ccb2SNeilBrown * The 'raid_disks' here is twice the raid_disks in r1conf.
598f19ccb2SNeilBrown * This allows space for each 'real' device can have a replacement in the
608f19ccb2SNeilBrown * second half of the array.
61ef740c37SChristoph Hellwig */
62ef740c37SChristoph Hellwig
63ef740c37SChristoph Hellwig struct pool_info {
64fd01b88cSNeilBrown struct mddev *mddev;
65ef740c37SChristoph Hellwig int raid_disks;
66ef740c37SChristoph Hellwig };
67ef740c37SChristoph Hellwig
68e8096360SNeilBrown struct r1conf {
69fd01b88cSNeilBrown struct mddev *mddev;
700eaf822cSJonathan Brassow struct raid1_info *mirrors; /* twice 'raid_disks' to
718f19ccb2SNeilBrown * allow for replacements.
728f19ccb2SNeilBrown */
73ef740c37SChristoph Hellwig int raid_disks;
74*2c27d09dSYu Kuai int nonrot_disks;
75ce550c20SNeilBrown
76ef740c37SChristoph Hellwig spinlock_t device_lock;
77ef740c37SChristoph Hellwig
789f2c9d12SNeilBrown /* list of 'struct r1bio' that need to be processed by raid1d,
799f2c9d12SNeilBrown * whether to retry a read, writeout a resync or recovery
809f2c9d12SNeilBrown * block, or anything else.
81ce550c20SNeilBrown */
82ef740c37SChristoph Hellwig struct list_head retry_list;
8355ce74d4SNeilBrown /* A separate list of r1bio which just need raid_end_bio_io called.
8455ce74d4SNeilBrown * This mustn't happen for writes which had any errors if the superblock
8555ce74d4SNeilBrown * needs to be written.
8655ce74d4SNeilBrown */
8755ce74d4SNeilBrown struct list_head bio_end_io_list;
88ce550c20SNeilBrown
89ce550c20SNeilBrown /* queue pending writes to be submitted on unplug */
90ef740c37SChristoph Hellwig struct bio_list pending_bio_list;
91ef740c37SChristoph Hellwig
92ce550c20SNeilBrown /* for use when syncing mirrors:
93ce550c20SNeilBrown * We don't allow both normal IO and resync/recovery IO at
94ce550c20SNeilBrown * the same time - resync/recovery can only happen when there
95ce550c20SNeilBrown * is no other IO. So when either is active, the other has to wait.
96ce550c20SNeilBrown * See more details description in raid1.c near raise_barrier().
97ce550c20SNeilBrown */
98ce550c20SNeilBrown wait_queue_head_t wait_barrier;
99ef740c37SChristoph Hellwig spinlock_t resync_lock;
10043ac9b84SXiao Ni atomic_t nr_sync_pending;
101824e47daScolyli@suse.de atomic_t *nr_pending;
102824e47daScolyli@suse.de atomic_t *nr_waiting;
103824e47daScolyli@suse.de atomic_t *nr_queued;
104824e47daScolyli@suse.de atomic_t *barrier;
105b364e3d0Smajianpeng int array_frozen;
106ce550c20SNeilBrown
107ce550c20SNeilBrown /* Set to 1 if a full sync is needed, (fresh device added).
108ef740c37SChristoph Hellwig * Cleared when a sync completes.
109ef740c37SChristoph Hellwig */
110ce550c20SNeilBrown int fullsync;
111ce550c20SNeilBrown
112ce550c20SNeilBrown /* When the same as mddev->recovery_disabled we don't allow
113ce550c20SNeilBrown * recovery to be attempted as we expect a read error.
1145389042fSNeilBrown */
115ce550c20SNeilBrown int recovery_disabled;
116ef740c37SChristoph Hellwig
117ce550c20SNeilBrown /* poolinfo contains information about the content of the
118ce550c20SNeilBrown * mempools - it changes when the array grows or shrinks
119ce550c20SNeilBrown */
120ef740c37SChristoph Hellwig struct pool_info *poolinfo;
121afeee514SKent Overstreet mempool_t r1bio_pool;
122afeee514SKent Overstreet mempool_t r1buf_pool;
123709ae487SNeilBrown
124afeee514SKent Overstreet struct bio_set bio_split;
125c230e7e5SNeilBrown
126ce550c20SNeilBrown /* temporary buffer to synchronous IO when attempting to repair
127ce550c20SNeilBrown * a read error.
128ce550c20SNeilBrown */
129ce550c20SNeilBrown struct page *tmppage;
130ce550c20SNeilBrown
131709ae487SNeilBrown /* When taking over an array from a different personality, we store
132709ae487SNeilBrown * the new thread here until we fully activate the array.
133709ae487SNeilBrown */
13444693154SYu Kuai struct md_thread __rcu *thread;
135c40f341fSGoldwyn Rodrigues
136c40f341fSGoldwyn Rodrigues /* Keep track of cluster resync window to send to other
137c40f341fSGoldwyn Rodrigues * nodes.
138c40f341fSGoldwyn Rodrigues */
139c40f341fSGoldwyn Rodrigues sector_t cluster_sync_low;
140c40f341fSGoldwyn Rodrigues sector_t cluster_sync_high;
141c40f341fSGoldwyn Rodrigues
142ef740c37SChristoph Hellwig };
143ef740c37SChristoph Hellwig
144ef740c37SChristoph Hellwig /*
145ef740c37SChristoph Hellwig * this is our 'private' RAID1 bio.
146ef740c37SChristoph Hellwig *
147ef740c37SChristoph Hellwig * it contains information about what kind of IO operations were started
148ef740c37SChristoph Hellwig * for this RAID1 operation, and about their status:
149ef740c37SChristoph Hellwig */
150ef740c37SChristoph Hellwig
1519f2c9d12SNeilBrown struct r1bio {
152ef740c37SChristoph Hellwig atomic_t remaining; /* 'have we finished' count,
153ef740c37SChristoph Hellwig * used from IRQ handlers
154ef740c37SChristoph Hellwig */
155ef740c37SChristoph Hellwig atomic_t behind_remaining; /* number of write-behind ios remaining
156ef740c37SChristoph Hellwig * in this BehindIO request
157ef740c37SChristoph Hellwig */
158ef740c37SChristoph Hellwig sector_t sector;
159ef740c37SChristoph Hellwig int sectors;
160ef740c37SChristoph Hellwig unsigned long state;
161fd01b88cSNeilBrown struct mddev *mddev;
162ef740c37SChristoph Hellwig /*
163ef740c37SChristoph Hellwig * original bio going to /dev/mdx
164ef740c37SChristoph Hellwig */
165ef740c37SChristoph Hellwig struct bio *master_bio;
166ef740c37SChristoph Hellwig /*
167ef740c37SChristoph Hellwig * if the IO is in READ direction, then this is where we read
168ef740c37SChristoph Hellwig */
169ef740c37SChristoph Hellwig int read_disk;
170ef740c37SChristoph Hellwig
171ef740c37SChristoph Hellwig struct list_head retry_list;
172841c1316SMing Lei
173841c1316SMing Lei /*
174841c1316SMing Lei * When R1BIO_BehindIO is set, we store pages for write behind
175841c1316SMing Lei * in behind_master_bio.
176841c1316SMing Lei */
177841c1316SMing Lei struct bio *behind_master_bio;
178841c1316SMing Lei
179ef740c37SChristoph Hellwig /*
180ef740c37SChristoph Hellwig * if the IO is in WRITE direction, then multiple bios are used.
181ef740c37SChristoph Hellwig * We choose the number when they are allocated.
182ef740c37SChristoph Hellwig */
183358369f0SGustavo A. R. Silva struct bio *bios[];
184ef740c37SChristoph Hellwig /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
185ef740c37SChristoph Hellwig };
186ef740c37SChristoph Hellwig
187ef740c37SChristoph Hellwig /* bits for r1bio.state */
188be306c29SNeilBrown enum r1bio_state {
189be306c29SNeilBrown R1BIO_Uptodate,
190be306c29SNeilBrown R1BIO_IsSync,
191be306c29SNeilBrown R1BIO_Degraded,
192be306c29SNeilBrown R1BIO_BehindIO,
193d2eb35acSNeilBrown /* Set ReadError on bios that experience a readerror so that
194d2eb35acSNeilBrown * raid1d knows what to do with them.
195d2eb35acSNeilBrown */
196be306c29SNeilBrown R1BIO_ReadError,
197ef740c37SChristoph Hellwig /* For write-behind requests, we call bi_end_io when
198ef740c37SChristoph Hellwig * the last non-write-behind device completes, providing
199ef740c37SChristoph Hellwig * any write was successful. Otherwise we call when
200ef740c37SChristoph Hellwig * any write-behind write succeeds, otherwise we call
201ef740c37SChristoph Hellwig * with failure when last write completes (and all failed).
202ef740c37SChristoph Hellwig * Record that bi_end_io was called with this flag...
203ef740c37SChristoph Hellwig */
204be306c29SNeilBrown R1BIO_Returned,
2054367af55SNeilBrown /* If a write for this request means we can clear some
2064367af55SNeilBrown * known-bad-block records, we set this flag
2074367af55SNeilBrown */
208be306c29SNeilBrown R1BIO_MadeGood,
209be306c29SNeilBrown R1BIO_WriteError,
2102e52d449SNeilBrown R1BIO_FailFast,
211be306c29SNeilBrown };
212fd76863eScolyli@suse.de
sector_to_idx(sector_t sector)213fd76863eScolyli@suse.de static inline int sector_to_idx(sector_t sector)
214fd76863eScolyli@suse.de {
215fd76863eScolyli@suse.de return hash_long(sector >> BARRIER_UNIT_SECTOR_BITS,
216fd76863eScolyli@suse.de BARRIER_BUCKETS_NR_BITS);
217fd76863eScolyli@suse.de }
218ef740c37SChristoph Hellwig #endif
219