drivers/md/dm-core.h

0001 /*
0002  * Internal header file _only_ for device mapper core
0003  *
0004  * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
0005  *
0006  * This file is released under the LGPL.
0007  */
0008
0009 #ifndef DM_CORE_INTERNAL_H
0010 #define DM_CORE_INTERNAL_H
0011
0012 #include <linux/kthread.h>
0013 #include <linux/ktime.h>
0014 #include <linux/blk-mq.h>
0015 #include <linux/blk-crypto-profile.h>
0016 #include <linux/jump_label.h>
0017
0018 #include <trace/events/block.h>
0019
0020 #include "dm.h"
0021 #include "dm-ima.h"
0022
0023 #define DM_RESERVED_MAX_IOS     1024
0024
0025 struct dm_io;
0026
0027 struct dm_kobject_holder {
0028     struct kobject kobj;
0029     struct completion completion;
0030 };
0031
0032 /*
0033  * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
0034  * DM targets must _not_ deference a mapped_device or dm_table to directly
0035  * access their members!
0036  */
0037
0038 /*
0039  * For mempools pre-allocation at the table loading time.
0040  */
0041 struct dm_md_mempools {
0042     struct bio_set bs;
0043     struct bio_set io_bs;
0044 };
0045
0046 struct mapped_device {
0047     struct mutex suspend_lock;
0048
0049     struct mutex table_devices_lock;
0050     struct list_head table_devices;
0051
0052     /*
0053      * The current mapping (struct dm_table *).
0054      * Use dm_get_live_table{_fast} or take suspend_lock for
0055      * dereference.
0056      */
0057     void __rcu *map;
0058
0059     unsigned long flags;
0060
0061     /* Protect queue and type against concurrent access. */
0062     struct mutex type_lock;
0063     enum dm_queue_mode type;
0064
0065     int numa_node_id;
0066     struct request_queue *queue;
0067
0068     atomic_t holders;
0069     atomic_t open_count;
0070
0071     struct dm_target *immutable_target;
0072     struct target_type *immutable_target_type;
0073
0074     char name[16];
0075     struct gendisk *disk;
0076     struct dax_device *dax_dev;
0077
0078     wait_queue_head_t wait;
0079     unsigned long __percpu *pending_io;
0080
0081     /* forced geometry settings */
0082     struct hd_geometry geometry;
0083
0084     /*
0085      * Processing queue (flush)
0086      */
0087     struct workqueue_struct *wq;
0088
0089     /*
0090      * A list of ios that arrived while we were suspended.
0091      */
0092     struct work_struct work;
0093     spinlock_t deferred_lock;
0094     struct bio_list deferred;
0095
0096     /*
0097      * requeue work context is needed for cloning one new bio
0098      * to represent the dm_io to be requeued, since each
0099      * dm_io may point to the original bio from FS.
0100      */
0101     struct work_struct requeue_work;
0102     struct dm_io *requeue_list;
0103
0104     void *interface_ptr;
0105
0106     /*
0107      * Event handling.
0108      */
0109     wait_queue_head_t eventq;
0110     atomic_t event_nr;
0111     atomic_t uevent_seq;
0112     struct list_head uevent_list;
0113     spinlock_t uevent_lock; /* Protect access to uevent_list */
0114
0115     /* for blk-mq request-based DM support */
0116     bool init_tio_pdu:1;
0117     struct blk_mq_tag_set *tag_set;
0118
0119     struct dm_stats stats;
0120
0121     /* the number of internal suspends */
0122     unsigned internal_suspend_count;
0123
0124     int swap_bios;
0125     struct semaphore swap_bios_semaphore;
0126     struct mutex swap_bios_lock;
0127
0128     /*
0129      * io objects are allocated from here.
0130      */
0131     struct dm_md_mempools *mempools;
0132
0133     /* kobject and completion */
0134     struct dm_kobject_holder kobj_holder;
0135
0136     struct srcu_struct io_barrier;
0137
0138 #ifdef CONFIG_BLK_DEV_ZONED
0139     unsigned int nr_zones;
0140     unsigned int *zwp_offset;
0141 #endif
0142
0143 #ifdef CONFIG_IMA
0144     struct dm_ima_measurements ima;
0145 #endif
0146 };
0147
0148 /*
0149  * Bits for the flags field of struct mapped_device.
0150  */
0151 #define DMF_BLOCK_IO_FOR_SUSPEND 0
0152 #define DMF_SUSPENDED 1
0153 #define DMF_FROZEN 2
0154 #define DMF_FREEING 3
0155 #define DMF_DELETING 4
0156 #define DMF_NOFLUSH_SUSPENDING 5
0157 #define DMF_DEFERRED_REMOVE 6
0158 #define DMF_SUSPENDED_INTERNALLY 7
0159 #define DMF_POST_SUSPENDING 8
0160 #define DMF_EMULATE_ZONE_APPEND 9
0161
0162 void disable_discard(struct mapped_device *md);
0163 void disable_write_zeroes(struct mapped_device *md);
0164
0165 static inline sector_t dm_get_size(struct mapped_device *md)
0166 {
0167     return get_capacity(md->disk);
0168 }
0169
0170 static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
0171 {
0172     return &md->stats;
0173 }
0174
0175 DECLARE_STATIC_KEY_FALSE(stats_enabled);
0176 DECLARE_STATIC_KEY_FALSE(swap_bios_enabled);
0177 DECLARE_STATIC_KEY_FALSE(zoned_enabled);
0178
0179 static inline bool dm_emulate_zone_append(struct mapped_device *md)
0180 {
0181     if (blk_queue_is_zoned(md->queue))
0182         return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
0183     return false;
0184 }
0185
0186 #define DM_TABLE_MAX_DEPTH 16
0187
0188 struct dm_table {
0189     struct mapped_device *md;
0190     enum dm_queue_mode type;
0191
0192     /* btree table */
0193     unsigned int depth;
0194     unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
0195     sector_t *index[DM_TABLE_MAX_DEPTH];
0196
0197     unsigned int num_targets;
0198     unsigned int num_allocated;
0199     sector_t *highs;
0200     struct dm_target *targets;
0201
0202     struct target_type *immutable_target_type;
0203
0204     bool integrity_supported:1;
0205     bool singleton:1;
0206     unsigned integrity_added:1;
0207
0208     /*
0209      * Indicates the rw permissions for the new logical
0210      * device.  This should be a combination of FMODE_READ
0211      * and FMODE_WRITE.
0212      */
0213     fmode_t mode;
0214
0215     /* a list of devices used by this table */
0216     struct list_head devices;
0217
0218     /* events get handed up using this callback */
0219     void (*event_fn)(void *);
0220     void *event_context;
0221
0222     struct dm_md_mempools *mempools;
0223
0224 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
0225     struct blk_crypto_profile *crypto_profile;
0226 #endif
0227 };
0228
0229 static inline struct dm_target *dm_table_get_target(struct dm_table *t,
0230                             unsigned int index)
0231 {
0232     BUG_ON(index >= t->num_targets);
0233     return t->targets + index;
0234 }
0235
0236 /*
0237  * One of these is allocated per clone bio.
0238  */
0239 #define DM_TIO_MAGIC 28714
0240 struct dm_target_io {
0241     unsigned short magic;
0242     blk_short_t flags;
0243     unsigned int target_bio_nr;
0244     struct dm_io *io;
0245     struct dm_target *ti;
0246     unsigned int *len_ptr;
0247     sector_t old_sector;
0248     struct bio clone;
0249 };
0250 #define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
0251 #define DM_IO_BIO_OFFSET \
0252     (offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
0253
0254 /*
0255  * dm_target_io flags
0256  */
0257 enum {
0258     DM_TIO_INSIDE_DM_IO,
0259     DM_TIO_IS_DUPLICATE_BIO
0260 };
0261
0262 static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)
0263 {
0264     return (tio->flags & (1U << bit)) != 0;
0265 }
0266
0267 static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)
0268 {
0269     tio->flags |= (1U << bit);
0270 }
0271
0272 static inline bool dm_tio_is_normal(struct dm_target_io *tio)
0273 {
0274     return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&
0275         !dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
0276 }
0277
0278 /*
0279  * One of these is allocated per original bio.
0280  * It contains the first clone used for that original.
0281  */
0282 #define DM_IO_MAGIC 19577
0283 struct dm_io {
0284     unsigned short magic;
0285     blk_short_t flags;
0286     spinlock_t lock;
0287     unsigned long start_time;
0288     void *data;
0289     struct dm_io *next;
0290     struct dm_stats_aux stats_aux;
0291     blk_status_t status;
0292     atomic_t io_count;
0293     struct mapped_device *md;
0294
0295     /* The three fields represent mapped part of original bio */
0296     struct bio *orig_bio;
0297     unsigned int sector_offset; /* offset to end of orig_bio */
0298     unsigned int sectors;
0299
0300     /* last member of dm_target_io is 'struct bio' */
0301     struct dm_target_io tio;
0302 };
0303
0304 /*
0305  * dm_io flags
0306  */
0307 enum {
0308     DM_IO_ACCOUNTED,
0309     DM_IO_WAS_SPLIT
0310 };
0311
0312 static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)
0313 {
0314     return (io->flags & (1U << bit)) != 0;
0315 }
0316
0317 static inline void dm_io_set_flag(struct dm_io *io, unsigned int bit)
0318 {
0319     io->flags |= (1U << bit);
0320 }
0321
0322 void dm_io_rewind(struct dm_io *io, struct bio_set *bs);
0323
0324 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
0325 {
0326     return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
0327 }
0328
0329 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
0330
0331 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
0332 {
0333     return !maxlen || strlen(result) + 1 >= maxlen;
0334 }
0335
0336 extern atomic_t dm_global_event_nr;
0337 extern wait_queue_head_t dm_global_eventq;
0338 void dm_issue_global_event(void);
0339
0340 #endif