Merge branch 'docs-next' of git://git.lwn.net/linux-2.6
[linux-2.6/next.git] / include / linux / genhd.h
blob297df45ffd0ad27e8219aaf3715a00d030f5bf54
1 #ifndef _LINUX_GENHD_H
2 #define _LINUX_GENHD_H
4 /*
5 * genhd.h Copyright (C) 1992 Drew Eckhardt
6 * Generic hard disk header file by
7 * Drew Eckhardt
9 * <drew@colorado.edu>
12 #include <linux/types.h>
13 #include <linux/kdev_t.h>
14 #include <linux/rcupdate.h>
16 #ifdef CONFIG_BLOCK
18 #define kobj_to_dev(k) container_of((k), struct device, kobj)
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))
24 extern struct device_type part_type;
25 extern struct kobject *block_depr;
26 extern struct class block_class;
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,
35 SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
37 LINUX_SWAP_PARTITION = 0x82,
38 LINUX_DATA_PARTITION = 0x83,
39 LINUX_LVM_PARTITION = 0x8e,
40 LINUX_RAID_PARTITION = 0xfd, /* autodetect RAID partition */
42 SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
43 NEW_SOLARIS_X86_PARTITION = 0xbf,
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 */
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 */
58 #define DISK_MAX_PARTS 256
59 #define DISK_NAME_LEN 32
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>
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));
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;
90 struct hd_struct {
91 sector_t start_sect;
92 sector_t nr_sects;
93 sector_t alignment_offset;
94 struct device __dev;
95 struct kobject *holder_dir;
96 int policy, partno;
97 #ifdef CONFIG_FAIL_MAKE_REQUEST
98 int make_it_fail;
99 #endif
100 unsigned long stamp;
101 int in_flight[2];
102 #ifdef CONFIG_SMP
103 struct disk_stats *dkstats;
104 #else
105 struct disk_stats dkstats;
106 #endif
107 struct rcu_head rcu_head;
110 #define GENHD_FL_REMOVABLE 1
111 #define GENHD_FL_DRIVERFS 2
112 #define GENHD_FL_MEDIA_CHANGE_NOTIFY 4
113 #define GENHD_FL_CD 8
114 #define GENHD_FL_UP 16
115 #define GENHD_FL_SUPPRESS_PARTITION_INFO 32
116 #define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
117 #define GENHD_FL_NATIVE_CAPACITY 128
119 #define BLK_SCSI_MAX_CMDS (256)
120 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
122 struct blk_scsi_cmd_filter {
123 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
124 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
125 struct kobject kobj;
128 struct disk_part_tbl {
129 struct rcu_head rcu_head;
130 int len;
131 struct hd_struct *last_lookup;
132 struct hd_struct *part[];
135 struct gendisk {
136 /* major, first_minor and minors are input parameters only,
137 * don't use directly. Use disk_devt() and disk_max_parts().
139 int major; /* major number of driver */
140 int first_minor;
141 int minors; /* maximum number of minors, =1 for
142 * disks that can't be partitioned. */
144 char disk_name[DISK_NAME_LEN]; /* name of major driver */
145 char *(*devnode)(struct gendisk *gd, mode_t *mode);
146 /* Array of pointers to partitions indexed by partno.
147 * Protected with matching bdev lock but stat and other
148 * non-critical accesses use RCU. Always access through
149 * helpers.
151 struct disk_part_tbl *part_tbl;
152 struct hd_struct part0;
154 const struct block_device_operations *fops;
155 struct request_queue *queue;
156 void *private_data;
158 int flags;
159 struct device *driverfs_dev; // FIXME: remove
160 struct kobject *slave_dir;
162 struct timer_rand_state *random;
164 atomic_t sync_io; /* RAID */
165 struct work_struct async_notify;
166 #ifdef CONFIG_BLK_DEV_INTEGRITY
167 struct blk_integrity *integrity;
168 #endif
169 int node_id;
172 static inline struct gendisk *part_to_disk(struct hd_struct *part)
174 if (likely(part)) {
175 if (part->partno)
176 return dev_to_disk(part_to_dev(part)->parent);
177 else
178 return dev_to_disk(part_to_dev(part));
180 return NULL;
183 static inline int disk_max_parts(struct gendisk *disk)
185 if (disk->flags & GENHD_FL_EXT_DEVT)
186 return DISK_MAX_PARTS;
187 return disk->minors;
190 static inline bool disk_partitionable(struct gendisk *disk)
192 return disk_max_parts(disk) > 1;
195 static inline dev_t disk_devt(struct gendisk *disk)
197 return disk_to_dev(disk)->devt;
200 static inline dev_t part_devt(struct hd_struct *part)
202 return part_to_dev(part)->devt;
205 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
207 static inline void disk_put_part(struct hd_struct *part)
209 if (likely(part))
210 put_device(part_to_dev(part));
214 * Smarter partition iterator without context limits.
216 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
217 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
218 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
219 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
221 struct disk_part_iter {
222 struct gendisk *disk;
223 struct hd_struct *part;
224 int idx;
225 unsigned int flags;
228 extern void disk_part_iter_init(struct disk_part_iter *piter,
229 struct gendisk *disk, unsigned int flags);
230 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
231 extern void disk_part_iter_exit(struct disk_part_iter *piter);
233 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
234 sector_t sector);
237 * Macros to operate on percpu disk statistics:
239 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
240 * and should be called between disk_stat_lock() and
241 * disk_stat_unlock().
243 * part_stat_read() can be called at any time.
245 * part_stat_{add|set_all}() and {init|free}_part_stats are for
246 * internal use only.
248 #ifdef CONFIG_SMP
249 #define part_stat_lock() ({ rcu_read_lock(); get_cpu(); })
250 #define part_stat_unlock() do { put_cpu(); rcu_read_unlock(); } while (0)
252 #define __part_stat_add(cpu, part, field, addnd) \
253 (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
255 #define part_stat_read(part, field) \
256 ({ \
257 typeof((part)->dkstats->field) res = 0; \
258 int i; \
259 for_each_possible_cpu(i) \
260 res += per_cpu_ptr((part)->dkstats, i)->field; \
261 res; \
264 static inline void part_stat_set_all(struct hd_struct *part, int value)
266 int i;
268 for_each_possible_cpu(i)
269 memset(per_cpu_ptr(part->dkstats, i), value,
270 sizeof(struct disk_stats));
273 static inline int init_part_stats(struct hd_struct *part)
275 part->dkstats = alloc_percpu(struct disk_stats);
276 if (!part->dkstats)
277 return 0;
278 return 1;
281 static inline void free_part_stats(struct hd_struct *part)
283 free_percpu(part->dkstats);
286 #else /* !CONFIG_SMP */
287 #define part_stat_lock() ({ rcu_read_lock(); 0; })
288 #define part_stat_unlock() rcu_read_unlock()
290 #define __part_stat_add(cpu, part, field, addnd) \
291 ((part)->dkstats.field += addnd)
293 #define part_stat_read(part, field) ((part)->dkstats.field)
295 static inline void part_stat_set_all(struct hd_struct *part, int value)
297 memset(&part->dkstats, value, sizeof(struct disk_stats));
300 static inline int init_part_stats(struct hd_struct *part)
302 return 1;
305 static inline void free_part_stats(struct hd_struct *part)
309 #endif /* CONFIG_SMP */
311 #define part_stat_add(cpu, part, field, addnd) do { \
312 __part_stat_add((cpu), (part), field, addnd); \
313 if ((part)->partno) \
314 __part_stat_add((cpu), &part_to_disk((part))->part0, \
315 field, addnd); \
316 } while (0)
318 #define part_stat_dec(cpu, gendiskp, field) \
319 part_stat_add(cpu, gendiskp, field, -1)
320 #define part_stat_inc(cpu, gendiskp, field) \
321 part_stat_add(cpu, gendiskp, field, 1)
322 #define part_stat_sub(cpu, gendiskp, field, subnd) \
323 part_stat_add(cpu, gendiskp, field, -subnd)
325 static inline void part_inc_in_flight(struct hd_struct *part, int rw)
327 part->in_flight[rw]++;
328 if (part->partno)
329 part_to_disk(part)->part0.in_flight[rw]++;
332 static inline void part_dec_in_flight(struct hd_struct *part, int rw)
334 part->in_flight[rw]--;
335 if (part->partno)
336 part_to_disk(part)->part0.in_flight[rw]--;
339 static inline int part_in_flight(struct hd_struct *part)
341 return part->in_flight[0] + part->in_flight[1];
344 /* block/blk-core.c */
345 extern void part_round_stats(int cpu, struct hd_struct *part);
347 /* block/genhd.c */
348 extern void add_disk(struct gendisk *disk);
349 extern void del_gendisk(struct gendisk *gp);
350 extern void unlink_gendisk(struct gendisk *gp);
351 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
352 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
354 extern void set_device_ro(struct block_device *bdev, int flag);
355 extern void set_disk_ro(struct gendisk *disk, int flag);
357 static inline int get_disk_ro(struct gendisk *disk)
359 return disk->part0.policy;
362 /* drivers/char/random.c */
363 extern void add_disk_randomness(struct gendisk *disk);
364 extern void rand_initialize_disk(struct gendisk *disk);
366 static inline sector_t get_start_sect(struct block_device *bdev)
368 return bdev->bd_part->start_sect;
370 static inline sector_t get_capacity(struct gendisk *disk)
372 return disk->part0.nr_sects;
374 static inline void set_capacity(struct gendisk *disk, sector_t size)
376 disk->part0.nr_sects = size;
379 #ifdef CONFIG_SOLARIS_X86_PARTITION
381 #define SOLARIS_X86_NUMSLICE 16
382 #define SOLARIS_X86_VTOC_SANE (0x600DDEEEUL)
384 struct solaris_x86_slice {
385 __le16 s_tag; /* ID tag of partition */
386 __le16 s_flag; /* permission flags */
387 __le32 s_start; /* start sector no of partition */
388 __le32 s_size; /* # of blocks in partition */
391 struct solaris_x86_vtoc {
392 unsigned int v_bootinfo[3]; /* info needed by mboot (unsupported) */
393 __le32 v_sanity; /* to verify vtoc sanity */
394 __le32 v_version; /* layout version */
395 char v_volume[8]; /* volume name */
396 __le16 v_sectorsz; /* sector size in bytes */
397 __le16 v_nparts; /* number of partitions */
398 unsigned int v_reserved[10]; /* free space */
399 struct solaris_x86_slice
400 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
401 unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
402 char v_asciilabel[128]; /* for compatibility */
405 #endif /* CONFIG_SOLARIS_X86_PARTITION */
407 #ifdef CONFIG_BSD_DISKLABEL
409 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
410 * updated by Marc Espie <Marc.Espie@openbsd.org>
413 /* check against BSD src/sys/sys/disklabel.h for consistency */
415 #define BSD_DISKMAGIC (0x82564557UL) /* The disk magic number */
416 #define BSD_MAXPARTITIONS 16
417 #define OPENBSD_MAXPARTITIONS 16
418 #define BSD_FS_UNUSED 0 /* disklabel unused partition entry ID */
419 struct bsd_disklabel {
420 __le32 d_magic; /* the magic number */
421 __s16 d_type; /* drive type */
422 __s16 d_subtype; /* controller/d_type specific */
423 char d_typename[16]; /* type name, e.g. "eagle" */
424 char d_packname[16]; /* pack identifier */
425 __u32 d_secsize; /* # of bytes per sector */
426 __u32 d_nsectors; /* # of data sectors per track */
427 __u32 d_ntracks; /* # of tracks per cylinder */
428 __u32 d_ncylinders; /* # of data cylinders per unit */
429 __u32 d_secpercyl; /* # of data sectors per cylinder */
430 __u32 d_secperunit; /* # of data sectors per unit */
431 __u16 d_sparespertrack; /* # of spare sectors per track */
432 __u16 d_sparespercyl; /* # of spare sectors per cylinder */
433 __u32 d_acylinders; /* # of alt. cylinders per unit */
434 __u16 d_rpm; /* rotational speed */
435 __u16 d_interleave; /* hardware sector interleave */
436 __u16 d_trackskew; /* sector 0 skew, per track */
437 __u16 d_cylskew; /* sector 0 skew, per cylinder */
438 __u32 d_headswitch; /* head switch time, usec */
439 __u32 d_trkseek; /* track-to-track seek, usec */
440 __u32 d_flags; /* generic flags */
441 #define NDDATA 5
442 __u32 d_drivedata[NDDATA]; /* drive-type specific information */
443 #define NSPARE 5
444 __u32 d_spare[NSPARE]; /* reserved for future use */
445 __le32 d_magic2; /* the magic number (again) */
446 __le16 d_checksum; /* xor of data incl. partitions */
448 /* filesystem and partition information: */
449 __le16 d_npartitions; /* number of partitions in following */
450 __le32 d_bbsize; /* size of boot area at sn0, bytes */
451 __le32 d_sbsize; /* max size of fs superblock, bytes */
452 struct bsd_partition { /* the partition table */
453 __le32 p_size; /* number of sectors in partition */
454 __le32 p_offset; /* starting sector */
455 __le32 p_fsize; /* filesystem basic fragment size */
456 __u8 p_fstype; /* filesystem type, see below */
457 __u8 p_frag; /* filesystem fragments per block */
458 __le16 p_cpg; /* filesystem cylinders per group */
459 } d_partitions[BSD_MAXPARTITIONS]; /* actually may be more */
462 #endif /* CONFIG_BSD_DISKLABEL */
464 #ifdef CONFIG_UNIXWARE_DISKLABEL
466 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
467 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
470 #define UNIXWARE_DISKMAGIC (0xCA5E600DUL) /* The disk magic number */
471 #define UNIXWARE_DISKMAGIC2 (0x600DDEEEUL) /* The slice table magic nr */
472 #define UNIXWARE_NUMSLICE 16
473 #define UNIXWARE_FS_UNUSED 0 /* Unused slice entry ID */
475 struct unixware_slice {
476 __le16 s_label; /* label */
477 __le16 s_flags; /* permission flags */
478 __le32 start_sect; /* starting sector */
479 __le32 nr_sects; /* number of sectors in slice */
482 struct unixware_disklabel {
483 __le32 d_type; /* drive type */
484 __le32 d_magic; /* the magic number */
485 __le32 d_version; /* version number */
486 char d_serial[12]; /* serial number of the device */
487 __le32 d_ncylinders; /* # of data cylinders per device */
488 __le32 d_ntracks; /* # of tracks per cylinder */
489 __le32 d_nsectors; /* # of data sectors per track */
490 __le32 d_secsize; /* # of bytes per sector */
491 __le32 d_part_start; /* # of first sector of this partition */
492 __le32 d_unknown1[12]; /* ? */
493 __le32 d_alt_tbl; /* byte offset of alternate table */
494 __le32 d_alt_len; /* byte length of alternate table */
495 __le32 d_phys_cyl; /* # of physical cylinders per device */
496 __le32 d_phys_trk; /* # of physical tracks per cylinder */
497 __le32 d_phys_sec; /* # of physical sectors per track */
498 __le32 d_phys_bytes; /* # of physical bytes per sector */
499 __le32 d_unknown2; /* ? */
500 __le32 d_unknown3; /* ? */
501 __le32 d_pad[8]; /* pad */
503 struct unixware_vtoc {
504 __le32 v_magic; /* the magic number */
505 __le32 v_version; /* version number */
506 char v_name[8]; /* volume name */
507 __le16 v_nslices; /* # of slices */
508 __le16 v_unknown1; /* ? */
509 __le32 v_reserved[10]; /* reserved */
510 struct unixware_slice
511 v_slice[UNIXWARE_NUMSLICE]; /* slice headers */
512 } vtoc;
514 }; /* 408 */
516 #endif /* CONFIG_UNIXWARE_DISKLABEL */
518 #ifdef CONFIG_MINIX_SUBPARTITION
519 # define MINIX_NR_SUBPARTITIONS 4
520 #endif /* CONFIG_MINIX_SUBPARTITION */
522 #define ADDPART_FLAG_NONE 0
523 #define ADDPART_FLAG_RAID 1
524 #define ADDPART_FLAG_WHOLEDISK 2
526 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
527 extern void blk_free_devt(dev_t devt);
528 extern dev_t blk_lookup_devt(const char *name, int partno);
529 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
531 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
532 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
533 extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
534 int partno, sector_t start,
535 sector_t len, int flags);
536 extern void delete_partition(struct gendisk *, int);
537 extern void printk_all_partitions(void);
539 extern struct gendisk *alloc_disk_node(int minors, int node_id);
540 extern struct gendisk *alloc_disk(int minors);
541 extern struct kobject *get_disk(struct gendisk *disk);
542 extern void put_disk(struct gendisk *disk);
543 extern void blk_register_region(dev_t devt, unsigned long range,
544 struct module *module,
545 struct kobject *(*probe)(dev_t, int *, void *),
546 int (*lock)(dev_t, void *),
547 void *data);
548 extern void blk_unregister_region(dev_t devt, unsigned long range);
550 extern ssize_t part_size_show(struct device *dev,
551 struct device_attribute *attr, char *buf);
552 extern ssize_t part_stat_show(struct device *dev,
553 struct device_attribute *attr, char *buf);
554 extern ssize_t part_inflight_show(struct device *dev,
555 struct device_attribute *attr, char *buf);
556 #ifdef CONFIG_FAIL_MAKE_REQUEST
557 extern ssize_t part_fail_show(struct device *dev,
558 struct device_attribute *attr, char *buf);
559 extern ssize_t part_fail_store(struct device *dev,
560 struct device_attribute *attr,
561 const char *buf, size_t count);
562 #endif /* CONFIG_FAIL_MAKE_REQUEST */
564 #else /* CONFIG_BLOCK */
566 static inline void printk_all_partitions(void) { }
568 static inline dev_t blk_lookup_devt(const char *name, int partno)
570 dev_t devt = MKDEV(0, 0);
571 return devt;
574 #endif /* CONFIG_BLOCK */
576 #endif /* _LINUX_GENHD_H */