1 #ifndef _LINUX_GENHD_H
2 #define _LINUX_GENHD_H
3
4 /*
5 * genhd.h Copyright (C) 1992 Drew Eckhardt
6 * Generic hard disk header file by
7 * Drew Eckhardt
8 *
9 * <drew@colorado.edu>
10 */
11
12 #include <linux/types.h>
13 #include <linux/kdev_t.h>
14 #include <linux/rcupdate.h>
15 #include <linux/slab.h>
16
17 #ifdef CONFIG_BLOCK
18
19 #define dev_to_disk(device) container_of((device), struct gendisk, part0.__dev)
20 #define dev_to_part(device) container_of((device), struct hd_struct, __dev)
21 #define disk_to_dev(disk) (&(disk)->part0.__dev)
22 #define part_to_dev(part) (&((part)->__dev))
23
24 extern struct device_type part_type;
25 extern struct kobject *block_depr;
26 extern struct class block_class;
27
28 enum {
29 /* These three have identical behaviour; use the second one if DOS FDISK gets
30 confused about extended/logical partitions starting past cylinder 1023. */
31 DOS_EXTENDED_PARTITION = 5,
32 LINUX_EXTENDED_PARTITION = 0x85,
33 WIN98_EXTENDED_PARTITION = 0x0f,
34
35 SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
36
37 LINUX_SWAP_PARTITION = 0x82,
38 LINUX_DATA_PARTITION = 0x83,
39 LINUX_LVM_PARTITION = 0x8e,
40 LINUX_RAID_PARTITION = 0xfd, /* autodetect RAID partition */
41
42 SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
43 NEW_SOLARIS_X86_PARTITION = 0xbf,
44
45 DM6_AUX1PARTITION = 0x51, /* no DDO: use xlated geom */
46 DM6_AUX3PARTITION = 0x53, /* no DDO: use xlated geom */
47 DM6_PARTITION = 0x54, /* has DDO: use xlated geom & offset */
48 EZD_PARTITION = 0x55, /* EZ-DRIVE */
49
50 FREEBSD_PARTITION = 0xa5, /* FreeBSD Partition ID */
51 OPENBSD_PARTITION = 0xa6, /* OpenBSD Partition ID */
52 NETBSD_PARTITION = 0xa9, /* NetBSD Partition ID */
53 BSDI_PARTITION = 0xb7, /* BSDI Partition ID */
54 MINIX_PARTITION = 0x81, /* Minix Partition ID */
55 UNIXWARE_PARTITION = 0x63, /* Same as GNU_HURD and SCO Unix */
56 };
57
58 #define DISK_MAX_PARTS 256
59 #define DISK_NAME_LEN 32
60
61 #include <linux/major.h>
62 #include <linux/device.h>
63 #include <linux/smp.h>
64 #include <linux/string.h>
65 #include <linux/fs.h>
66 #include <linux/workqueue.h>
67
68 struct partition {
69 unsigned char boot_ind; /* 0x80 - active */
70 unsigned char head; /* starting head */
71 unsigned char sector; /* starting sector */
72 unsigned char cyl; /* starting cylinder */
73 unsigned char sys_ind; /* What partition type */
74 unsigned char end_head; /* end head */
75 unsigned char end_sector; /* end sector */
76 unsigned char end_cyl; /* end cylinder */
77 __le32 start_sect; /* starting sector counting from 0 */
78 __le32 nr_sects; /* nr of sectors in partition */
79 } __attribute__((packed));
80
81 struct disk_stats {
82 unsigned long sectors[2]; /* READs and WRITEs */
83 unsigned long ios[2];
84 unsigned long merges[2];
85 unsigned long ticks[2];
86 unsigned long io_ticks;
87 unsigned long time_in_queue;
88 };
89
90 #define PARTITION_META_INFO_VOLNAMELTH 64
91 /*
92 * Enough for the string representation of any kind of UUID plus NULL.
93 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
94 */
95 #define PARTITION_META_INFO_UUIDLTH 37
96
97 struct partition_meta_info {
98 char uuid[PARTITION_META_INFO_UUIDLTH];
99 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
100 };
101
102 struct hd_struct {
103 sector_t start_sect;
104 /*
105 * nr_sects is protected by sequence counter. One might extend a
106 * partition while IO is happening to it and update of nr_sects
107 * can be non-atomic on 32bit machines with 64bit sector_t.
108 */
109 sector_t nr_sects;
110 seqcount_t nr_sects_seq;
111 sector_t alignment_offset;
112 unsigned int discard_alignment;
113 struct device __dev;
114 struct kobject *holder_dir;
115 int policy, partno;
116 struct partition_meta_info *info;
117 #ifdef CONFIG_FAIL_MAKE_REQUEST
118 int make_it_fail;
119 #endif
120 unsigned long stamp;
121 atomic_t in_flight[2];
122 #ifdef CONFIG_SMP
123 struct disk_stats __percpu *dkstats;
124 #else
125 struct disk_stats dkstats;
126 #endif
127 atomic_t ref;
128 struct rcu_head rcu_head;
129 };
130
131 #define GENHD_FL_REMOVABLE 1
132 /* 2 is unused */
133 #define GENHD_FL_MEDIA_CHANGE_NOTIFY 4
134 #define GENHD_FL_CD 8
135 #define GENHD_FL_UP 16
136 #define GENHD_FL_SUPPRESS_PARTITION_INFO 32
137 #define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
138 #define GENHD_FL_NATIVE_CAPACITY 128
139 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256
140 #define GENHD_FL_NO_PART_SCAN 512
141
142 enum {
143 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
144 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
145 };
146
147 #define BLK_SCSI_MAX_CMDS (256)
148 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
149
150 struct blk_scsi_cmd_filter {
151 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
152 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
153 struct kobject kobj;
154 };
155
156 struct disk_part_tbl {
157 struct rcu_head rcu_head;
158 int len;
159 struct hd_struct __rcu *last_lookup;
160 struct hd_struct __rcu *part[];
161 };
162
163 struct disk_events;
164
165 struct gendisk {
166 /* major, first_minor and minors are input parameters only,
167 * don't use directly. Use disk_devt() and disk_max_parts().
168 */
169 int major; /* major number of driver */
170 int first_minor;
171 int minors; /* maximum number of minors, =1 for
172 * disks that can't be partitioned. */
173
174 char disk_name[DISK_NAME_LEN]; /* name of major driver */
175 char *(*devnode)(struct gendisk *gd, umode_t *mode);
176
177 unsigned int events; /* supported events */
178 unsigned int async_events; /* async events, subset of all */
179
180 /* Array of pointers to partitions indexed by partno.
181 * Protected with matching bdev lock but stat and other
182 * non-critical accesses use RCU. Always access through
183 * helpers.
184 */
185 struct disk_part_tbl __rcu *part_tbl;
186 struct hd_struct part0;
187
188 const struct block_device_operations *fops;
189 struct request_queue *queue;
190 void *private_data;
191
192 int flags;
193 struct device *driverfs_dev; // FIXME: remove
194 struct kobject *slave_dir;
195
196 struct timer_rand_state *random;
197 atomic_t sync_io; /* RAID */
198 struct disk_events *ev;
199 #ifdef CONFIG_BLK_DEV_INTEGRITY
200 struct blk_integrity *integrity;
201 #endif
202 int node_id;
203 };
204
205 static inline struct gendisk *part_to_disk(struct hd_struct *part)
206 {
207 if (likely(part)) {
208 if (part->partno)
209 return dev_to_disk(part_to_dev(part)->parent);
210 else
211 return dev_to_disk(part_to_dev(part));
212 }
213 return NULL;
214 }
215
216 static inline void part_pack_uuid(const u8 *uuid_str, u8 *to)
217 {
218 int i;
219 for (i = 0; i < 16; ++i) {
220 *to++ = (hex_to_bin(*uuid_str) << 4) |
221 (hex_to_bin(*(uuid_str + 1)));
222 uuid_str += 2;
223 switch (i) {
224 case 3:
225 case 5:
226 case 7:
227 case 9:
228 uuid_str++;
229 continue;
230 }
231 }
232 }
233
234 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
235 {
236 part_pack_uuid(uuid_str, to);
237 return 0;
238 }
239
240 static inline int disk_max_parts(struct gendisk *disk)
241 {
242 if (disk->flags & GENHD_FL_EXT_DEVT)
243 return DISK_MAX_PARTS;
244 return disk->minors;
245 }
246
247 static inline bool disk_part_scan_enabled(struct gendisk *disk)
248 {
249 return disk_max_parts(disk) > 1 &&
250 !(disk->flags & GENHD_FL_NO_PART_SCAN);
251 }
252
253 static inline dev_t disk_devt(struct gendisk *disk)
254 {
255 return disk_to_dev(disk)->devt;
256 }
257
258 static inline dev_t part_devt(struct hd_struct *part)
259 {
260 return part_to_dev(part)->devt;
261 }
262
263 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
264
265 static inline void disk_put_part(struct hd_struct *part)
266 {
267 if (likely(part))
268 put_device(part_to_dev(part));
269 }
270
271 /*
272 * Smarter partition iterator without context limits.
273 */
274 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
275 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
276 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
277 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
278
279 struct disk_part_iter {
280 struct gendisk *disk;
281 struct hd_struct *part;
282 int idx;
283 unsigned int flags;
284 };
285
286 extern void disk_part_iter_init(struct disk_part_iter *piter,
287 struct gendisk *disk, unsigned int flags);
288 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
289 extern void disk_part_iter_exit(struct disk_part_iter *piter);
290
291 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
292 sector_t sector);
293
294 /*
295 * Macros to operate on percpu disk statistics:
296 *
297 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
298 * and should be called between disk_stat_lock() and
299 * disk_stat_unlock().
300 *
301 * part_stat_read() can be called at any time.
302 *
303 * part_stat_{add|set_all}() and {init|free}_part_stats are for
304 * internal use only.
305 */
306 #ifdef CONFIG_SMP
307 #define part_stat_lock() ({ rcu_read_lock(); get_cpu(); })
308 #define part_stat_unlock() do { put_cpu(); rcu_read_unlock(); } while (0)
309
310 #define __part_stat_add(cpu, part, field, addnd) \
311 (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
312
313 #define part_stat_read(part, field) \
314 ({ \
315 typeof((part)->dkstats->field) res = 0; \
316 unsigned int _cpu; \
317 for_each_possible_cpu(_cpu) \
318 res += per_cpu_ptr((part)->dkstats, _cpu)->field; \
319 res; \
320 })
321
322 static inline void part_stat_set_all(struct hd_struct *part, int value)
323 {
324 int i;
325
326 for_each_possible_cpu(i)
327 memset(per_cpu_ptr(part->dkstats, i), value,
328 sizeof(struct disk_stats));
329 }
330
331 static inline int init_part_stats(struct hd_struct *part)
332 {
333 part->dkstats = alloc_percpu(struct disk_stats);
334 if (!part->dkstats)
335 return 0;
336 return 1;
337 }
338
339 static inline void free_part_stats(struct hd_struct *part)
340 {
341 free_percpu(part->dkstats);
342 }
343
344 #else /* !CONFIG_SMP */
345 #define part_stat_lock() ({ rcu_read_lock(); 0; })
346 #define part_stat_unlock() rcu_read_unlock()
347
348 #define __part_stat_add(cpu, part, field, addnd) \
349 ((part)->dkstats.field += addnd)
350
351 #define part_stat_read(part, field) ((part)->dkstats.field)
352
353 static inline void part_stat_set_all(struct hd_struct *part, int value)
354 {
355 memset(&part->dkstats, value, sizeof(struct disk_stats));
356 }
357
358 static inline int init_part_stats(struct hd_struct *part)
359 {
360 return 1;
361 }
362
363 static inline void free_part_stats(struct hd_struct *part)
364 {
365 }
366
367 #endif /* CONFIG_SMP */
368
369 #define part_stat_add(cpu, part, field, addnd) do { \
370 __part_stat_add((cpu), (part), field, addnd); \
371 if ((part)->partno) \
372 __part_stat_add((cpu), &part_to_disk((part))->part0, \
373 field, addnd); \
374 } while (0)
375
376 #define part_stat_dec(cpu, gendiskp, field) \
377 part_stat_add(cpu, gendiskp, field, -1)
378 #define part_stat_inc(cpu, gendiskp, field) \
379 part_stat_add(cpu, gendiskp, field, 1)
380 #define part_stat_sub(cpu, gendiskp, field, subnd) \
381 part_stat_add(cpu, gendiskp, field, -subnd)
382
383 static inline void part_inc_in_flight(struct hd_struct *part, int rw)
384 {
385 atomic_inc(&part->in_flight[rw]);
386 if (part->partno)
387 atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
388 }
389
390 static inline void part_dec_in_flight(struct hd_struct *part, int rw)
391 {
392 atomic_dec(&part->in_flight[rw]);
393 if (part->partno)
394 atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
395 }
396
397 static inline int part_in_flight(struct hd_struct *part)
398 {
399 return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
400 }
401
402 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
403 {
404 if (disk)
405 return kzalloc_node(sizeof(struct partition_meta_info),
406 GFP_KERNEL, disk->node_id);
407 return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
408 }
409
410 static inline void free_part_info(struct hd_struct *part)
411 {
412 kfree(part->info);
413 }
414
415 /* block/blk-core.c */
416 extern void part_round_stats(int cpu, struct hd_struct *part);
417
418 /* block/genhd.c */
419 extern void add_disk(struct gendisk *disk);
420 extern void del_gendisk(struct gendisk *gp);
421 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
422 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
423
424 extern void set_device_ro(struct block_device *bdev, int flag);
425 extern void set_disk_ro(struct gendisk *disk, int flag);
426
427 static inline int get_disk_ro(struct gendisk *disk)
428 {
429 return disk->part0.policy;
430 }
431
432 extern void disk_block_events(struct gendisk *disk);
433 extern void disk_unblock_events(struct gendisk *disk);
434 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
435 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
436
437 /* drivers/char/random.c */
438 extern void add_disk_randomness(struct gendisk *disk);
439 extern void rand_initialize_disk(struct gendisk *disk);
440
441 static inline sector_t get_start_sect(struct block_device *bdev)
442 {
443 return bdev->bd_part->start_sect;
444 }
445 static inline sector_t get_capacity(struct gendisk *disk)
446 {
447 return disk->part0.nr_sects;
448 }
449 static inline void set_capacity(struct gendisk *disk, sector_t size)
450 {
451 disk->part0.nr_sects = size;
452 }
453
454 #ifdef CONFIG_SOLARIS_X86_PARTITION
455
456 #define SOLARIS_X86_NUMSLICE 16
457 #define SOLARIS_X86_VTOC_SANE (0x600DDEEEUL)
458
459 struct solaris_x86_slice {
460 __le16 s_tag; /* ID tag of partition */
461 __le16 s_flag; /* permission flags */
462 __le32 s_start; /* start sector no of partition */
463 __le32 s_size; /* # of blocks in partition */
464 };
465
466 struct solaris_x86_vtoc {
467 unsigned int v_bootinfo[3]; /* info needed by mboot (unsupported) */
468 __le32 v_sanity; /* to verify vtoc sanity */
469 __le32 v_version; /* layout version */
470 char v_volume[8]; /* volume name */
471 __le16 v_sectorsz; /* sector size in bytes */
472 __le16 v_nparts; /* number of partitions */
473 unsigned int v_reserved[10]; /* free space */
474 struct solaris_x86_slice
475 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
476 unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
477 char v_asciilabel[128]; /* for compatibility */
478 };
479
480 #endif /* CONFIG_SOLARIS_X86_PARTITION */
481
482 #ifdef CONFIG_BSD_DISKLABEL
483 /*
484 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
485 * updated by Marc Espie <Marc.Espie@openbsd.org>
486 */
487
488 /* check against BSD src/sys/sys/disklabel.h for consistency */
489
490 #define BSD_DISKMAGIC (0x82564557UL) /* The disk magic number */
491 #define BSD_MAXPARTITIONS 16
492 #define OPENBSD_MAXPARTITIONS 16
493 #define BSD_FS_UNUSED 0 /* disklabel unused partition entry ID */
494 struct bsd_disklabel {
495 __le32 d_magic; /* the magic number */
496 __s16 d_type; /* drive type */
497 __s16 d_subtype; /* controller/d_type specific */
498 char d_typename[16]; /* type name, e.g. "eagle" */
499 char d_packname[16]; /* pack identifier */
500 __u32 d_secsize; /* # of bytes per sector */
501 __u32 d_nsectors; /* # of data sectors per track */
502 __u32 d_ntracks; /* # of tracks per cylinder */
503 __u32 d_ncylinders; /* # of data cylinders per unit */
504 __u32 d_secpercyl; /* # of data sectors per cylinder */
505 __u32 d_secperunit; /* # of data sectors per unit */
506 __u16 d_sparespertrack; /* # of spare sectors per track */
507 __u16 d_sparespercyl; /* # of spare sectors per cylinder */
508 __u32 d_acylinders; /* # of alt. cylinders per unit */
509 __u16 d_rpm; /* rotational speed */
510 __u16 d_interleave; /* hardware sector interleave */
511 __u16 d_trackskew; /* sector 0 skew, per track */
512 __u16 d_cylskew; /* sector 0 skew, per cylinder */
513 __u32 d_headswitch; /* head switch time, usec */
514 __u32 d_trkseek; /* track-to-track seek, usec */
515 __u32 d_flags; /* generic flags */
516 #define NDDATA 5
517 __u32 d_drivedata[NDDATA]; /* drive-type specific information */
518 #define NSPARE 5
519 __u32 d_spare[NSPARE]; /* reserved for future use */
520 __le32 d_magic2; /* the magic number (again) */
521 __le16 d_checksum; /* xor of data incl. partitions */
522
523 /* filesystem and partition information: */
524 __le16 d_npartitions; /* number of partitions in following */
525 __le32 d_bbsize; /* size of boot area at sn0, bytes */
526 __le32 d_sbsize; /* max size of fs superblock, bytes */
527 struct bsd_partition { /* the partition table */
528 __le32 p_size; /* number of sectors in partition */
529 __le32 p_offset; /* starting sector */
530 __le32 p_fsize; /* filesystem basic fragment size */
531 __u8 p_fstype; /* filesystem type, see below */
532 __u8 p_frag; /* filesystem fragments per block */
533 __le16 p_cpg; /* filesystem cylinders per group */
534 } d_partitions[BSD_MAXPARTITIONS]; /* actually may be more */
535 };
536
537 #endif /* CONFIG_BSD_DISKLABEL */
538
539 #ifdef CONFIG_UNIXWARE_DISKLABEL
540 /*
541 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
542 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
543 */
544
545 #define UNIXWARE_DISKMAGIC (0xCA5E600DUL) /* The disk magic number */
546 #define UNIXWARE_DISKMAGIC2 (0x600DDEEEUL) /* The slice table magic nr */
547 #define UNIXWARE_NUMSLICE 16
548 #define UNIXWARE_FS_UNUSED 0 /* Unused slice entry ID */
549
550 struct unixware_slice {
551 __le16 s_label; /* label */
552 __le16 s_flags; /* permission flags */
553 __le32 start_sect; /* starting sector */
554 __le32 nr_sects; /* number of sectors in slice */
555 };
556
557 struct unixware_disklabel {
558 __le32 d_type; /* drive type */
559 __le32 d_magic; /* the magic number */
560 __le32 d_version; /* version number */
561 char d_serial[12]; /* serial number of the device */
562 __le32 d_ncylinders; /* # of data cylinders per device */
563 __le32 d_ntracks; /* # of tracks per cylinder */
564 __le32 d_nsectors; /* # of data sectors per track */
565 __le32 d_secsize; /* # of bytes per sector */
566 __le32 d_part_start; /* # of first sector of this partition */
567 __le32 d_unknown1[12]; /* ? */
568 __le32 d_alt_tbl; /* byte offset of alternate table */
569 __le32 d_alt_len; /* byte length of alternate table */
570 __le32 d_phys_cyl; /* # of physical cylinders per device */
571 __le32 d_phys_trk; /* # of physical tracks per cylinder */
572 __le32 d_phys_sec; /* # of physical sectors per track */
573 __le32 d_phys_bytes; /* # of physical bytes per sector */
574 __le32 d_unknown2; /* ? */
575 __le32 d_unknown3; /* ? */
576 __le32 d_pad[8]; /* pad */
577
578 struct unixware_vtoc {
579 __le32 v_magic; /* the magic number */
580 __le32 v_version; /* version number */
581 char v_name[8]; /* volume name */
582 __le16 v_nslices; /* # of slices */
583 __le16 v_unknown1; /* ? */
584 __le32 v_reserved[10]; /* reserved */
585 struct unixware_slice
586 v_slice[UNIXWARE_NUMSLICE]; /* slice headers */
587 } vtoc;
588
589 }; /* 408 */
590
591 #endif /* CONFIG_UNIXWARE_DISKLABEL */
592
593 #ifdef CONFIG_MINIX_SUBPARTITION
594 # define MINIX_NR_SUBPARTITIONS 4
595 #endif /* CONFIG_MINIX_SUBPARTITION */
596
597 #define ADDPART_FLAG_NONE 0
598 #define ADDPART_FLAG_RAID 1
599 #define ADDPART_FLAG_WHOLEDISK 2
600
601 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
602 extern void blk_free_devt(dev_t devt);
603 extern dev_t blk_lookup_devt(const char *name, int partno);
604 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
605
606 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
607 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
608 extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
609 extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
610 int partno, sector_t start,
611 sector_t len, int flags,
612 struct partition_meta_info
613 *info);
614 extern void __delete_partition(struct hd_struct *);
615 extern void delete_partition(struct gendisk *, int);
616 extern void printk_all_partitions(void);
617
618 extern struct gendisk *alloc_disk_node(int minors, int node_id);
619 extern struct gendisk *alloc_disk(int minors);
620 extern struct kobject *get_disk(struct gendisk *disk);
621 extern void put_disk(struct gendisk *disk);
622 extern void blk_register_region(dev_t devt, unsigned long range,
623 struct module *module,
624 struct kobject *(*probe)(dev_t, int *, void *),
625 int (*lock)(dev_t, void *),
626 void *data);
627 extern void blk_unregister_region(dev_t devt, unsigned long range);
628
629 extern ssize_t part_size_show(struct device *dev,
630 struct device_attribute *attr, char *buf);
631 extern ssize_t part_stat_show(struct device *dev,
632 struct device_attribute *attr, char *buf);
633 extern ssize_t part_inflight_show(struct device *dev,
634 struct device_attribute *attr, char *buf);
635 #ifdef CONFIG_FAIL_MAKE_REQUEST
636 extern ssize_t part_fail_show(struct device *dev,
637 struct device_attribute *attr, char *buf);
638 extern ssize_t part_fail_store(struct device *dev,
639 struct device_attribute *attr,
640 const char *buf, size_t count);
641 #endif /* CONFIG_FAIL_MAKE_REQUEST */
642
643 static inline void hd_ref_init(struct hd_struct *part)
644 {
645 atomic_set(&part->ref, 1);
646 smp_mb();
647 }
648
649 static inline void hd_struct_get(struct hd_struct *part)
650 {
651 atomic_inc(&part->ref);
652 smp_mb__after_atomic_inc();
653 }
654
655 static inline int hd_struct_try_get(struct hd_struct *part)
656 {
657 return atomic_inc_not_zero(&part->ref);
658 }
659
660 static inline void hd_struct_put(struct hd_struct *part)
661 {
662 if (atomic_dec_and_test(&part->ref))
663 __delete_partition(part);
664 }
665
666 /*
667 * Any access of part->nr_sects which is not protected by partition
668 * bd_mutex or gendisk bdev bd_mutex, should be done using this
669 * accessor function.
670 *
671 * Code written along the lines of i_size_read() and i_size_write().
672 * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
673 * on.
674 */
675 static inline sector_t part_nr_sects_read(struct hd_struct *part)
676 {
677 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
678 sector_t nr_sects;
679 unsigned seq;
680 do {
681 seq = read_seqcount_begin(&part->nr_sects_seq);
682 nr_sects = part->nr_sects;
683 } while (read_seqcount_retry(&part->nr_sects_seq, seq));
684 return nr_sects;
685 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
686 sector_t nr_sects;
687
688 preempt_disable();
689 nr_sects = part->nr_sects;
690 preempt_enable();
691 return nr_sects;
692 #else
693 return part->nr_sects;
694 #endif
695 }
696
697 /*
698 * Should be called with mutex lock held (typically bd_mutex) of partition
699 * to provide mutual exlusion among writers otherwise seqcount might be
700 * left in wrong state leaving the readers spinning infinitely.
701 */
702 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
703 {
704 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
705 write_seqcount_begin(&part->nr_sects_seq);
706 part->nr_sects = size;
707 write_seqcount_end(&part->nr_sects_seq);
708 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
709 preempt_disable();
710 part->nr_sects = size;
711 preempt_enable();
712 #else
713 part->nr_sects = size;
714 #endif
715 }
716
717 #else /* CONFIG_BLOCK */
718
719 static inline void printk_all_partitions(void) { }
720
721 static inline dev_t blk_lookup_devt(const char *name, int partno)
722 {
723 dev_t devt = MKDEV(0, 0);
724 return devt;
725 }
726
727 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
728 {
729 return -EINVAL;
730 }
731 #endif /* CONFIG_BLOCK */
732
733 #endif /* _LINUX_GENHD_H */
734
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