drivers/md/dm-core.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Internal header file _only_ for device mapper core
   4  *
   5  * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
   6  *
   7  * This file is released under the LGPL.
   8  */
   9
  10 #ifndef DM_CORE_INTERNAL_H
  11 #define DM_CORE_INTERNAL_H
  12
  13 #include <linux/kthread.h>
  14 #include <linux/ktime.h>
  15 #include <linux/blk-mq.h>
  16 #include <linux/blk-crypto-profile.h>
  17 #include <linux/jump_label.h>
  18
  19 #include <trace/events/block.h>
  20
  21 #include "dm.h"
  22 #include "dm-ima.h"
  23
  24 #define DM_RESERVED_MAX_IOS             1024
  25 #define DM_MAX_TARGETS                  1048576
  26 #define DM_MAX_TARGET_PARAMS            1024
  27
  28 struct dm_io;
  29
  30 struct dm_kobject_holder {
  31         struct kobject kobj;
  32         struct completion completion;
  33 };
  34
  35 /*
  36  * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
  37  * DM targets must _not_ deference a mapped_device or dm_table to directly
  38  * access their members!
  39  */
  40
  41 /*
  42  * For mempools pre-allocation at the table loading time.
  43  */
  44 struct dm_md_mempools {
  45         struct bio_set bs;
  46         struct bio_set io_bs;
  47 };
  48
  49 struct mapped_device {
  50         struct mutex suspend_lock;
  51
  52         struct mutex table_devices_lock;
  53         struct list_head table_devices;
  54
  55         /*
  56          * The current mapping (struct dm_table *).
  57          * Use dm_get_live_table{_fast} or take suspend_lock for
  58          * dereference.
  59          */
  60         void __rcu *map;
  61
  62         unsigned long flags;
  63
  64         /* Protect queue and type against concurrent access. */
  65         struct mutex type_lock;
  66         enum dm_queue_mode type;
  67
  68         int numa_node_id;
  69         struct request_queue *queue;
  70
  71         atomic_t holders;
  72         atomic_t open_count;
  73
  74         struct dm_target *immutable_target;
  75         struct target_type *immutable_target_type;
  76
  77         char name[16];
  78         struct gendisk *disk;
  79         struct dax_device *dax_dev;
  80
  81         wait_queue_head_t wait;
  82         unsigned long __percpu *pending_io;
  83
  84         /* forced geometry settings */
  85         struct hd_geometry geometry;
  86
  87         /*
  88          * Processing queue (flush)
  89          */
  90         struct workqueue_struct *wq;
  91
  92         /*
  93          * A list of ios that arrived while we were suspended.
  94          */
  95         struct work_struct work;
  96         spinlock_t deferred_lock;
  97         struct bio_list deferred;
  98
  99         /*
 100          * requeue work context is needed for cloning one new bio
 101          * to represent the dm_io to be requeued, since each
 102          * dm_io may point to the original bio from FS.
 103          */
 104         struct work_struct requeue_work;
 105         struct dm_io *requeue_list;
 106
 107         void *interface_ptr;
 108
 109         /*
 110          * Event handling.
 111          */
 112         wait_queue_head_t eventq;
 113         atomic_t event_nr;
 114         atomic_t uevent_seq;
 115         struct list_head uevent_list;
 116         spinlock_t uevent_lock; /* Protect access to uevent_list */
 117
 118         /* for blk-mq request-based DM support */
 119         bool init_tio_pdu:1;
 120         struct blk_mq_tag_set *tag_set;
 121
 122         struct dm_stats stats;
 123
 124         /* the number of internal suspends */
 125         unsigned int internal_suspend_count;
 126
 127         int swap_bios;
 128         struct semaphore swap_bios_semaphore;
 129         struct mutex swap_bios_lock;
 130
 131         /*
 132          * io objects are allocated from here.
 133          */
 134         struct dm_md_mempools *mempools;
 135
 136         /* kobject and completion */
 137         struct dm_kobject_holder kobj_holder;
 138
 139         struct srcu_struct io_barrier;
 140
 141 #ifdef CONFIG_BLK_DEV_ZONED
 142         unsigned int nr_zones;
 143         void *zone_revalidate_map;
 144 #endif
 145
 146 #ifdef CONFIG_IMA
 147         struct dm_ima_measurements ima;
 148 #endif
 149 };
 150
 151 /*
 152  * Bits for the flags field of struct mapped_device.
 153  */
 154 #define DMF_BLOCK_IO_FOR_SUSPEND 0
 155 #define DMF_SUSPENDED 1
 156 #define DMF_FROZEN 2
 157 #define DMF_FREEING 3
 158 #define DMF_DELETING 4
 159 #define DMF_NOFLUSH_SUSPENDING 5
 160 #define DMF_DEFERRED_REMOVE 6
 161 #define DMF_SUSPENDED_INTERNALLY 7
 162 #define DMF_POST_SUSPENDING 8
 163 #define DMF_EMULATE_ZONE_APPEND 9
 164
 165 void disable_discard(struct mapped_device *md);
 166 void disable_write_zeroes(struct mapped_device *md);
 167
 168 static inline sector_t dm_get_size(struct mapped_device *md)
 169 {
 170         return get_capacity(md->disk);
 171 }
 172
 173 static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
 174 {
 175         return &md->stats;
 176 }
 177
 178 DECLARE_STATIC_KEY_FALSE(stats_enabled);
 179 DECLARE_STATIC_KEY_FALSE(swap_bios_enabled);
 180 DECLARE_STATIC_KEY_FALSE(zoned_enabled);
 181
 182 static inline bool dm_emulate_zone_append(struct mapped_device *md)
 183 {
 184         if (blk_queue_is_zoned(md->queue))
 185                 return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
 186         return false;
 187 }
 188
 189 #define DM_TABLE_MAX_DEPTH 16
 190
 191 struct dm_table {
 192         struct mapped_device *md;
 193         enum dm_queue_mode type;
 194
 195         /* btree table */
 196         unsigned int depth;
 197         unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
 198         sector_t *index[DM_TABLE_MAX_DEPTH];
 199
 200         unsigned int num_targets;
 201         unsigned int num_allocated;
 202         sector_t *highs;
 203         struct dm_target *targets;
 204
 205         struct target_type *immutable_target_type;
 206
 207         bool integrity_supported:1;
 208         bool singleton:1;
 209         /* set if all the targets in the table have "flush_bypasses_map" set */
 210         bool flush_bypasses_map:1;
 211
 212         /*
 213          * Indicates the rw permissions for the new logical device.  This
 214          * should be a combination of BLK_OPEN_READ and BLK_OPEN_WRITE.
 215          */
 216         blk_mode_t mode;
 217
 218         /* a list of devices used by this table */
 219         struct list_head devices;
 220         struct rw_semaphore devices_lock;
 221
 222         /* events get handed up using this callback */
 223         void (*event_fn)(void *data);
 224         void *event_context;
 225
 226         struct dm_md_mempools *mempools;
 227
 228 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 229         struct blk_crypto_profile *crypto_profile;
 230 #endif
 231 };
 232
 233 static inline struct dm_target *dm_table_get_target(struct dm_table *t,
 234                                                     unsigned int index)
 235 {
 236         BUG_ON(index >= t->num_targets);
 237         return t->targets + index;
 238 }
 239
 240 /*
 241  * One of these is allocated per clone bio.
 242  */
 243 #define DM_TIO_MAGIC 28714
 244 struct dm_target_io {
 245         unsigned short magic;
 246         blk_short_t flags;
 247         unsigned int target_bio_nr;
 248         struct dm_io *io;
 249         struct dm_target *ti;
 250         unsigned int *len_ptr;
 251         sector_t old_sector;
 252         struct bio clone;
 253 };
 254 #define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
 255 #define DM_IO_BIO_OFFSET \
 256         (offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
 257
 258 /*
 259  * dm_target_io flags
 260  */
 261 enum {
 262         DM_TIO_INSIDE_DM_IO,
 263         DM_TIO_IS_DUPLICATE_BIO
 264 };
 265
 266 static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)
 267 {
 268         return (tio->flags & (1U << bit)) != 0;
 269 }
 270
 271 static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)
 272 {
 273         tio->flags |= (1U << bit);
 274 }
 275
 276 static inline bool dm_tio_is_normal(struct dm_target_io *tio)
 277 {
 278         return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&
 279                 !dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
 280 }
 281
 282 /*
 283  * One of these is allocated per original bio.
 284  * It contains the first clone used for that original.
 285  */
 286 #define DM_IO_MAGIC 19577
 287 struct dm_io {
 288         unsigned short magic;
 289         blk_short_t flags;
 290         spinlock_t lock;
 291         unsigned long start_time;
 292         void *data;
 293         struct dm_io *next;
 294         struct dm_stats_aux stats_aux;
 295         blk_status_t status;
 296         atomic_t io_count;
 297         struct mapped_device *md;
 298
 299         /* The three fields represent mapped part of original bio */
 300         struct bio *orig_bio;
 301         unsigned int sector_offset; /* offset to end of orig_bio */
 302         unsigned int sectors;
 303
 304         /* last member of dm_target_io is 'struct bio' */
 305         struct dm_target_io tio;
 306 };
 307
 308 /*
 309  * dm_io flags
 310  */
 311 enum {
 312         DM_IO_ACCOUNTED,
 313         DM_IO_WAS_SPLIT,
 314         DM_IO_BLK_STAT
 315 };
 316
 317 static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)
 318 {
 319         return (io->flags & (1U << bit)) != 0;
 320 }
 321
 322 static inline void dm_io_set_flag(struct dm_io *io, unsigned int bit)
 323 {
 324         io->flags |= (1U << bit);
 325 }
 326
 327 void dm_io_rewind(struct dm_io *io, struct bio_set *bs);
 328
 329 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
 330 {
 331         return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
 332 }
 333
 334 unsigned int __dm_get_module_param(unsigned int *module_param, unsigned int def, unsigned int max);
 335
 336 static inline bool dm_message_test_buffer_overflow(char *result, unsigned int maxlen)
 337 {
 338         return !maxlen || strlen(result) + 1 >= maxlen;
 339 }
 340
 341 extern atomic_t dm_global_event_nr;
 342 extern wait_queue_head_t dm_global_eventq;
 343 void dm_issue_global_event(void);
 344
 345 #endif