1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_GENHD_H
3 #define _LINUX_GENHD_H
4
5 /*
6 * genhd.h Copyright (C) 1992 Drew Eckhardt
7 * Generic hard disk header file by
8 * Drew Eckhardt
9 *
10 * <drew@colorado.edu>
11 */
12
13 #include <linux/types.h>
14 #include <linux/kdev_t.h>
15 #include <linux/rcupdate.h>
16 #include <linux/slab.h>
17 #include <linux/percpu-refcount.h>
18 #include <linux/uuid.h>
19 #include <linux/blk_types.h>
20 #include <asm/local.h>
21
22 #define dev_to_disk(device) container_of((device), struct gendisk, part0.__dev)
23 #define dev_to_part(device) container_of((device), struct hd_struct, __dev)
24 #define disk_to_dev(disk) (&(disk)->part0.__dev)
25 #define part_to_dev(part) (&((part)->__dev))
26
27 extern const struct device_type disk_type;
28 extern struct device_type part_type;
29 extern struct class block_class;
30
31 #define DISK_MAX_PARTS 256
32 #define DISK_NAME_LEN 32
33
34 #include <linux/major.h>
35 #include <linux/device.h>
36 #include <linux/smp.h>
37 #include <linux/string.h>
38 #include <linux/fs.h>
39 #include <linux/workqueue.h>
40
41 #define PARTITION_META_INFO_VOLNAMELTH 64
42 /*
43 * Enough for the string representation of any kind of UUID plus NULL.
44 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
45 */
46 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
47
48 struct partition_meta_info {
49 char uuid[PARTITION_META_INFO_UUIDLTH];
50 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
51 };
52
53 struct hd_struct {
54 sector_t start_sect;
55 /*
56 * nr_sects is protected by sequence counter. One might extend a
57 * partition while IO is happening to it and update of nr_sects
58 * can be non-atomic on 32bit machines with 64bit sector_t.
59 */
60 sector_t nr_sects;
61 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
62 seqcount_t nr_sects_seq;
63 #endif
64 unsigned long stamp;
65 struct disk_stats __percpu *dkstats;
66 struct percpu_ref ref;
67
68 struct device __dev;
69 struct kobject *holder_dir;
70 int policy, partno;
71 struct partition_meta_info *info;
72 #ifdef CONFIG_FAIL_MAKE_REQUEST
73 int make_it_fail;
74 #endif
75 struct rcu_work rcu_work;
76 };
77
78 /**
79 * DOC: genhd capability flags
80 *
81 * ``GENHD_FL_REMOVABLE`` (0x0001): indicates that the block device
82 * gives access to removable media.
83 * When set, the device remains present even when media is not
84 * inserted.
85 * Must not be set for devices which are removed entirely when the
86 * media is removed.
87 *
88 * ``GENHD_FL_CD`` (0x0008): the block device is a CD-ROM-style
89 * device.
90 * Affects responses to the ``CDROM_GET_CAPABILITY`` ioctl.
91 *
92 * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
93 * with a similar meaning to network interfaces.
94 *
95 * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
96 * partition information in ``/proc/partitions`` or in the output of
97 * printk_all_partitions().
98 * Used for the null block device and some MMC devices.
99 *
100 * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
101 * dynamic ``dev_t``, i.e. it wants extended device numbers
102 * (``BLOCK_EXT_MAJOR``).
103 * This affects the maximum number of partitions.
104 *
105 * ``GENHD_FL_NATIVE_CAPACITY`` (0x0080): based on information in the
106 * partition table, the device's capacity has been extended to its
107 * native capacity; i.e. the device has hidden capacity used by one
108 * of the partitions (this is a flag used so that native capacity is
109 * only ever unlocked once).
110 *
111 * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
112 * blocked whenever a writer holds an exclusive lock.
113 *
114 * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
115 * Used for loop devices in their default settings and some MMC
116 * devices.
117 *
118 * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
119 * doesn't produce events, doesn't appear in sysfs, and doesn't have
120 * an associated ``bdev``.
121 * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
122 * ``GENHD_FL_NO_PART_SCAN``.
123 * Used for multipath devices.
124 */
125 #define GENHD_FL_REMOVABLE 0x0001
126 /* 2 is unused (used to be GENHD_FL_DRIVERFS) */
127 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
128 #define GENHD_FL_CD 0x0008
129 #define GENHD_FL_UP 0x0010
130 #define GENHD_FL_SUPPRESS_PARTITION_INFO 0x0020
131 #define GENHD_FL_EXT_DEVT 0x0040
132 #define GENHD_FL_NATIVE_CAPACITY 0x0080
133 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 0x0100
134 #define GENHD_FL_NO_PART_SCAN 0x0200
135 #define GENHD_FL_HIDDEN 0x0400
136
137 enum {
138 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
139 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
140 };
141
142 enum {
143 /* Poll even if events_poll_msecs is unset */
144 DISK_EVENT_FLAG_POLL = 1 << 0,
145 /* Forward events to udev */
146 DISK_EVENT_FLAG_UEVENT = 1 << 1,
147 };
148
149 struct disk_part_tbl {
150 struct rcu_head rcu_head;
151 int len;
152 struct hd_struct __rcu *last_lookup;
153 struct hd_struct __rcu *part[];
154 };
155
156 struct disk_events;
157 struct badblocks;
158
159 struct blk_integrity {
160 const struct blk_integrity_profile *profile;
161 unsigned char flags;
162 unsigned char tuple_size;
163 unsigned char interval_exp;
164 unsigned char tag_size;
165 };
166
167 struct gendisk {
168 /* major, first_minor and minors are input parameters only,
169 * don't use directly. Use disk_devt() and disk_max_parts().
170 */
171 int major; /* major number of driver */
172 int first_minor;
173 int minors; /* maximum number of minors, =1 for
174 * disks that can't be partitioned. */
175
176 char disk_name[DISK_NAME_LEN]; /* name of major driver */
177
178 unsigned short events; /* supported events */
179 unsigned short event_flags; /* flags related to event processing */
180
181 /* Array of pointers to partitions indexed by partno.
182 * Protected with matching bdev lock but stat and other
183 * non-critical accesses use RCU. Always access through
184 * helpers.
185 */
186 struct disk_part_tbl __rcu *part_tbl;
187 struct hd_struct part0;
188
189 const struct block_device_operations *fops;
190 struct request_queue *queue;
191 void *private_data;
192
193 int flags;
194 unsigned long state;
195 #define GD_NEED_PART_SCAN 0
196 struct rw_semaphore lookup_sem;
197 struct kobject *slave_dir;
198
199 struct timer_rand_state *random;
200 atomic_t sync_io; /* RAID */
201 struct disk_events *ev;
202 #ifdef CONFIG_BLK_DEV_INTEGRITY
203 struct kobject integrity_kobj;
204 #endif /* CONFIG_BLK_DEV_INTEGRITY */
205 #if IS_ENABLED(CONFIG_CDROM)
206 struct cdrom_device_info *cdi;
207 #endif
208 int node_id;
209 struct badblocks *bb;
210 struct lockdep_map lockdep_map;
211 };
212
213 #if IS_REACHABLE(CONFIG_CDROM)
214 #define disk_to_cdi(disk) ((disk)->cdi)
215 #else
216 #define disk_to_cdi(disk) NULL
217 #endif
218
part_to_disk(struct hd_struct * part)219 static inline struct gendisk *part_to_disk(struct hd_struct *part)
220 {
221 if (likely(part)) {
222 if (part->partno)
223 return dev_to_disk(part_to_dev(part)->parent);
224 else
225 return dev_to_disk(part_to_dev(part));
226 }
227 return NULL;
228 }
229
disk_max_parts(struct gendisk * disk)230 static inline int disk_max_parts(struct gendisk *disk)
231 {
232 if (disk->flags & GENHD_FL_EXT_DEVT)
233 return DISK_MAX_PARTS;
234 return disk->minors;
235 }
236
disk_part_scan_enabled(struct gendisk * disk)237 static inline bool disk_part_scan_enabled(struct gendisk *disk)
238 {
239 return disk_max_parts(disk) > 1 &&
240 !(disk->flags & GENHD_FL_NO_PART_SCAN);
241 }
242
disk_devt(struct gendisk * disk)243 static inline dev_t disk_devt(struct gendisk *disk)
244 {
245 return MKDEV(disk->major, disk->first_minor);
246 }
247
part_devt(struct hd_struct * part)248 static inline dev_t part_devt(struct hd_struct *part)
249 {
250 return part_to_dev(part)->devt;
251 }
252
253 extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
254 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
255
disk_put_part(struct hd_struct * part)256 static inline void disk_put_part(struct hd_struct *part)
257 {
258 if (likely(part))
259 put_device(part_to_dev(part));
260 }
261
hd_sects_seq_init(struct hd_struct * p)262 static inline void hd_sects_seq_init(struct hd_struct *p)
263 {
264 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
265 seqcount_init(&p->nr_sects_seq);
266 #endif
267 }
268
269 /*
270 * Smarter partition iterator without context limits.
271 */
272 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
273 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
274 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
275 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
276
277 struct disk_part_iter {
278 struct gendisk *disk;
279 struct hd_struct *part;
280 int idx;
281 unsigned int flags;
282 };
283
284 extern void disk_part_iter_init(struct disk_part_iter *piter,
285 struct gendisk *disk, unsigned int flags);
286 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
287 extern void disk_part_iter_exit(struct disk_part_iter *piter);
288 extern bool disk_has_partitions(struct gendisk *disk);
289
290 /* block/genhd.c */
291 extern void device_add_disk(struct device *parent, struct gendisk *disk,
292 const struct attribute_group **groups);
add_disk(struct gendisk * disk)293 static inline void add_disk(struct gendisk *disk)
294 {
295 device_add_disk(NULL, disk, NULL);
296 }
297 extern void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk);
add_disk_no_queue_reg(struct gendisk * disk)298 static inline void add_disk_no_queue_reg(struct gendisk *disk)
299 {
300 device_add_disk_no_queue_reg(NULL, disk);
301 }
302
303 extern void del_gendisk(struct gendisk *gp);
304 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
305 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
306
307 extern void set_device_ro(struct block_device *bdev, int flag);
308 extern void set_disk_ro(struct gendisk *disk, int flag);
309
get_disk_ro(struct gendisk * disk)310 static inline int get_disk_ro(struct gendisk *disk)
311 {
312 return disk->part0.policy;
313 }
314
315 extern void disk_block_events(struct gendisk *disk);
316 extern void disk_unblock_events(struct gendisk *disk);
317 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
318 bool set_capacity_revalidate_and_notify(struct gendisk *disk, sector_t size,
319 bool update_bdev);
320
321 /* drivers/char/random.c */
322 extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;
323 extern void rand_initialize_disk(struct gendisk *disk);
324
get_start_sect(struct block_device * bdev)325 static inline sector_t get_start_sect(struct block_device *bdev)
326 {
327 return bdev->bd_part->start_sect;
328 }
get_capacity(struct gendisk * disk)329 static inline sector_t get_capacity(struct gendisk *disk)
330 {
331 return disk->part0.nr_sects;
332 }
set_capacity(struct gendisk * disk,sector_t size)333 static inline void set_capacity(struct gendisk *disk, sector_t size)
334 {
335 disk->part0.nr_sects = size;
336 }
337
338 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
339 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
340 int blk_drop_partitions(struct block_device *bdev);
341
342 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
343 extern struct kobject *get_disk_and_module(struct gendisk *disk);
344 extern void put_disk(struct gendisk *disk);
345 extern void put_disk_and_module(struct gendisk *disk);
346 extern void blk_register_region(dev_t devt, unsigned long range,
347 struct module *module,
348 struct kobject *(*probe)(dev_t, int *, void *),
349 int (*lock)(dev_t, void *),
350 void *data);
351 extern void blk_unregister_region(dev_t devt, unsigned long range);
352
353 #define alloc_disk_node(minors, node_id) \
354 ({ \
355 static struct lock_class_key __key; \
356 const char *__name; \
357 struct gendisk *__disk; \
358 \
359 __name = "(gendisk_completion)"#minors"("#node_id")"; \
360 \
361 __disk = __alloc_disk_node(minors, node_id); \
362 \
363 if (__disk) \
364 lockdep_init_map(&__disk->lockdep_map, __name, &__key, 0); \
365 \
366 __disk; \
367 })
368
369 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
370
371 int register_blkdev(unsigned int major, const char *name);
372 void unregister_blkdev(unsigned int major, const char *name);
373
374 void revalidate_disk_size(struct gendisk *disk, bool verbose);
375 bool bdev_check_media_change(struct block_device *bdev);
376 int __invalidate_device(struct block_device *bdev, bool kill_dirty);
377 void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors);
378
379 /* for drivers/char/raw.c: */
380 int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
381 long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
382
383 #ifdef CONFIG_SYSFS
384 int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
385 void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk);
386 #else
bd_link_disk_holder(struct block_device * bdev,struct gendisk * disk)387 static inline int bd_link_disk_holder(struct block_device *bdev,
388 struct gendisk *disk)
389 {
390 return 0;
391 }
bd_unlink_disk_holder(struct block_device * bdev,struct gendisk * disk)392 static inline void bd_unlink_disk_holder(struct block_device *bdev,
393 struct gendisk *disk)
394 {
395 }
396 #endif /* CONFIG_SYSFS */
397
398 #ifdef CONFIG_BLOCK
399 void printk_all_partitions(void);
400 dev_t blk_lookup_devt(const char *name, int partno);
401 #else /* CONFIG_BLOCK */
printk_all_partitions(void)402 static inline void printk_all_partitions(void)
403 {
404 }
blk_lookup_devt(const char * name,int partno)405 static inline dev_t blk_lookup_devt(const char *name, int partno)
406 {
407 dev_t devt = MKDEV(0, 0);
408 return devt;
409 }
410 #endif /* CONFIG_BLOCK */
411
412 #endif /* _LINUX_GENHD_H */
413
