5 * genhd.h Copyright (C) 1992 Drew Eckhardt
6 * Generic hard disk header file by
12 #include <linux/types.h>
13 #include <linux/kdev_t.h>
14 #include <linux/rcupdate.h>
15 #include <linux/slab.h>
16 #include <linux/percpu-refcount.h>
17 #include <linux/uuid.h>
21 #define dev_to_disk(device) container_of((device), struct gendisk, part0.__dev)
22 #define dev_to_part(device) container_of((device), struct hd_struct, __dev)
23 #define disk_to_dev(disk) (&(disk)->part0.__dev)
24 #define part_to_dev(part) (&((part)->__dev))
26 extern struct device_type part_type;
27 extern struct kobject *block_depr;
28 extern struct class block_class;
31 /* These three have identical behaviour; use the second one if DOS FDISK gets
32 confused about extended/logical partitions starting past cylinder 1023. */
33 DOS_EXTENDED_PARTITION = 5,
34 LINUX_EXTENDED_PARTITION = 0x85,
35 WIN98_EXTENDED_PARTITION = 0x0f,
37 SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
39 LINUX_SWAP_PARTITION = 0x82,
40 LINUX_DATA_PARTITION = 0x83,
41 LINUX_LVM_PARTITION = 0x8e,
42 LINUX_RAID_PARTITION = 0xfd, /* autodetect RAID partition */
44 SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
45 NEW_SOLARIS_X86_PARTITION = 0xbf,
47 DM6_AUX1PARTITION = 0x51, /* no DDO: use xlated geom */
48 DM6_AUX3PARTITION = 0x53, /* no DDO: use xlated geom */
49 DM6_PARTITION = 0x54, /* has DDO: use xlated geom & offset */
50 EZD_PARTITION = 0x55, /* EZ-DRIVE */
52 FREEBSD_PARTITION = 0xa5, /* FreeBSD Partition ID */
53 OPENBSD_PARTITION = 0xa6, /* OpenBSD Partition ID */
54 NETBSD_PARTITION = 0xa9, /* NetBSD Partition ID */
55 BSDI_PARTITION = 0xb7, /* BSDI Partition ID */
56 MINIX_PARTITION = 0x81, /* Minix Partition ID */
57 UNIXWARE_PARTITION = 0x63, /* Same as GNU_HURD and SCO Unix */
60 #define DISK_MAX_PARTS 256
61 #define DISK_NAME_LEN 32
63 #include <linux/major.h>
64 #include <linux/device.h>
65 #include <linux/smp.h>
66 #include <linux/string.h>
68 #include <linux/workqueue.h>
71 unsigned char boot_ind; /* 0x80 - active */
72 unsigned char head; /* starting head */
73 unsigned char sector; /* starting sector */
74 unsigned char cyl; /* starting cylinder */
75 unsigned char sys_ind; /* What partition type */
76 unsigned char end_head; /* end head */
77 unsigned char end_sector; /* end sector */
78 unsigned char end_cyl; /* end cylinder */
79 __le32 start_sect; /* starting sector counting from 0 */
80 __le32 nr_sects; /* nr of sectors in partition */
81 } __attribute__((packed));
84 unsigned long sectors[2]; /* READs and WRITEs */
86 unsigned long merges[2];
87 unsigned long ticks[2];
88 unsigned long io_ticks;
89 unsigned long time_in_queue;
92 #define PARTITION_META_INFO_VOLNAMELTH 64
94 * Enough for the string representation of any kind of UUID plus NULL.
95 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
97 #define PARTITION_META_INFO_UUIDLTH (UUID_STRING_LEN + 1)
99 struct partition_meta_info {
100 char uuid[PARTITION_META_INFO_UUIDLTH];
101 u8 volname[PARTITION_META_INFO_VOLNAMELTH];
107 * nr_sects is protected by sequence counter. One might extend a
108 * partition while IO is happening to it and update of nr_sects
109 * can be non-atomic on 32bit machines with 64bit sector_t.
112 seqcount_t nr_sects_seq;
113 sector_t alignment_offset;
114 unsigned int discard_alignment;
116 struct kobject *holder_dir;
118 struct partition_meta_info *info;
119 #ifdef CONFIG_FAIL_MAKE_REQUEST
123 atomic_t in_flight[2];
125 struct disk_stats __percpu *dkstats;
127 struct disk_stats dkstats;
129 struct percpu_ref ref;
130 struct rcu_head rcu_head;
133 #define GENHD_FL_REMOVABLE 1
135 #define GENHD_FL_MEDIA_CHANGE_NOTIFY 4
136 #define GENHD_FL_CD 8
137 #define GENHD_FL_UP 16
138 #define GENHD_FL_SUPPRESS_PARTITION_INFO 32
139 #define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
140 #define GENHD_FL_NATIVE_CAPACITY 128
141 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256
142 #define GENHD_FL_NO_PART_SCAN 512
145 DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
146 DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
149 #define BLK_SCSI_MAX_CMDS (256)
150 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
152 struct blk_scsi_cmd_filter {
153 unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
154 unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
158 struct disk_part_tbl {
159 struct rcu_head rcu_head;
161 struct hd_struct __rcu *last_lookup;
162 struct hd_struct __rcu *part[];
168 #if defined(CONFIG_BLK_DEV_INTEGRITY)
170 struct blk_integrity {
171 struct blk_integrity_profile *profile;
173 unsigned char tuple_size;
174 unsigned char interval_exp;
175 unsigned char tag_size;
178 #endif /* CONFIG_BLK_DEV_INTEGRITY */
181 /* major, first_minor and minors are input parameters only,
182 * don't use directly. Use disk_devt() and disk_max_parts().
184 int major; /* major number of driver */
186 int minors; /* maximum number of minors, =1 for
187 * disks that can't be partitioned. */
189 char disk_name[DISK_NAME_LEN]; /* name of major driver */
190 char *(*devnode)(struct gendisk *gd, umode_t *mode);
192 unsigned int events; /* supported events */
193 unsigned int async_events; /* async events, subset of all */
195 /* Array of pointers to partitions indexed by partno.
196 * Protected with matching bdev lock but stat and other
197 * non-critical accesses use RCU. Always access through
200 struct disk_part_tbl __rcu *part_tbl;
201 struct hd_struct part0;
203 const struct block_device_operations *fops;
204 struct request_queue *queue;
208 struct device *driverfs_dev; // FIXME: remove
209 struct kobject *slave_dir;
211 struct timer_rand_state *random;
212 atomic_t sync_io; /* RAID */
213 struct disk_events *ev;
214 #ifdef CONFIG_BLK_DEV_INTEGRITY
215 struct kobject integrity_kobj;
216 #endif /* CONFIG_BLK_DEV_INTEGRITY */
218 struct badblocks *bb;
221 static inline struct gendisk *part_to_disk(struct hd_struct *part)
225 return dev_to_disk(part_to_dev(part)->parent);
227 return dev_to_disk(part_to_dev(part));
232 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
234 uuid_be_to_bin(uuid_str, (uuid_be *)to);
238 static inline int disk_max_parts(struct gendisk *disk)
240 if (disk->flags & GENHD_FL_EXT_DEVT)
241 return DISK_MAX_PARTS;
245 static inline bool disk_part_scan_enabled(struct gendisk *disk)
247 return disk_max_parts(disk) > 1 &&
248 !(disk->flags & GENHD_FL_NO_PART_SCAN);
251 static inline dev_t disk_devt(struct gendisk *disk)
253 return disk_to_dev(disk)->devt;
256 static inline dev_t part_devt(struct hd_struct *part)
258 return part_to_dev(part)->devt;
261 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
263 static inline void disk_put_part(struct hd_struct *part)
266 put_device(part_to_dev(part));
270 * Smarter partition iterator without context limits.
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 */
277 struct disk_part_iter {
278 struct gendisk *disk;
279 struct hd_struct *part;
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);
289 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
293 * Macros to operate on percpu disk statistics:
295 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
296 * and should be called between disk_stat_lock() and
297 * disk_stat_unlock().
299 * part_stat_read() can be called at any time.
301 * part_stat_{add|set_all}() and {init|free}_part_stats are for
305 #define part_stat_lock() ({ rcu_read_lock(); get_cpu(); })
306 #define part_stat_unlock() do { put_cpu(); rcu_read_unlock(); } while (0)
308 #define __part_stat_add(cpu, part, field, addnd) \
309 (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
311 #define part_stat_read(part, field) \
313 typeof((part)->dkstats->field) res = 0; \
315 for_each_possible_cpu(_cpu) \
316 res += per_cpu_ptr((part)->dkstats, _cpu)->field; \
320 static inline void part_stat_set_all(struct hd_struct *part, int value)
324 for_each_possible_cpu(i)
325 memset(per_cpu_ptr(part->dkstats, i), value,
326 sizeof(struct disk_stats));
329 static inline int init_part_stats(struct hd_struct *part)
331 part->dkstats = alloc_percpu(struct disk_stats);
337 static inline void free_part_stats(struct hd_struct *part)
339 free_percpu(part->dkstats);
342 #else /* !CONFIG_SMP */
343 #define part_stat_lock() ({ rcu_read_lock(); 0; })
344 #define part_stat_unlock() rcu_read_unlock()
346 #define __part_stat_add(cpu, part, field, addnd) \
347 ((part)->dkstats.field += addnd)
349 #define part_stat_read(part, field) ((part)->dkstats.field)
351 static inline void part_stat_set_all(struct hd_struct *part, int value)
353 memset(&part->dkstats, value, sizeof(struct disk_stats));
356 static inline int init_part_stats(struct hd_struct *part)
361 static inline void free_part_stats(struct hd_struct *part)
365 #endif /* CONFIG_SMP */
367 #define part_stat_add(cpu, part, field, addnd) do { \
368 __part_stat_add((cpu), (part), field, addnd); \
369 if ((part)->partno) \
370 __part_stat_add((cpu), &part_to_disk((part))->part0, \
374 #define part_stat_dec(cpu, gendiskp, field) \
375 part_stat_add(cpu, gendiskp, field, -1)
376 #define part_stat_inc(cpu, gendiskp, field) \
377 part_stat_add(cpu, gendiskp, field, 1)
378 #define part_stat_sub(cpu, gendiskp, field, subnd) \
379 part_stat_add(cpu, gendiskp, field, -subnd)
381 static inline void part_inc_in_flight(struct hd_struct *part, int rw)
383 atomic_inc(&part->in_flight[rw]);
385 atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
388 static inline void part_dec_in_flight(struct hd_struct *part, int rw)
390 atomic_dec(&part->in_flight[rw]);
392 atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
395 static inline int part_in_flight(struct hd_struct *part)
397 return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
400 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
403 return kzalloc_node(sizeof(struct partition_meta_info),
404 GFP_KERNEL, disk->node_id);
405 return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
408 static inline void free_part_info(struct hd_struct *part)
413 /* block/blk-core.c */
414 extern void part_round_stats(int cpu, struct hd_struct *part);
417 extern void add_disk(struct gendisk *disk);
418 extern void del_gendisk(struct gendisk *gp);
419 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
420 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
422 extern void set_device_ro(struct block_device *bdev, int flag);
423 extern void set_disk_ro(struct gendisk *disk, int flag);
425 static inline int get_disk_ro(struct gendisk *disk)
427 return disk->part0.policy;
430 extern void disk_block_events(struct gendisk *disk);
431 extern void disk_unblock_events(struct gendisk *disk);
432 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
433 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
435 /* drivers/char/random.c */
436 extern void add_disk_randomness(struct gendisk *disk);
437 extern void rand_initialize_disk(struct gendisk *disk);
439 static inline sector_t get_start_sect(struct block_device *bdev)
441 return bdev->bd_part->start_sect;
443 static inline sector_t get_capacity(struct gendisk *disk)
445 return disk->part0.nr_sects;
447 static inline void set_capacity(struct gendisk *disk, sector_t size)
449 disk->part0.nr_sects = size;
452 #ifdef CONFIG_SOLARIS_X86_PARTITION
454 #define SOLARIS_X86_NUMSLICE 16
455 #define SOLARIS_X86_VTOC_SANE (0x600DDEEEUL)
457 struct solaris_x86_slice {
458 __le16 s_tag; /* ID tag of partition */
459 __le16 s_flag; /* permission flags */
460 __le32 s_start; /* start sector no of partition */
461 __le32 s_size; /* # of blocks in partition */
464 struct solaris_x86_vtoc {
465 unsigned int v_bootinfo[3]; /* info needed by mboot (unsupported) */
466 __le32 v_sanity; /* to verify vtoc sanity */
467 __le32 v_version; /* layout version */
468 char v_volume[8]; /* volume name */
469 __le16 v_sectorsz; /* sector size in bytes */
470 __le16 v_nparts; /* number of partitions */
471 unsigned int v_reserved[10]; /* free space */
472 struct solaris_x86_slice
473 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
474 unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
475 char v_asciilabel[128]; /* for compatibility */
478 #endif /* CONFIG_SOLARIS_X86_PARTITION */
480 #ifdef CONFIG_BSD_DISKLABEL
482 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
483 * updated by Marc Espie <Marc.Espie@openbsd.org>
486 /* check against BSD src/sys/sys/disklabel.h for consistency */
488 #define BSD_DISKMAGIC (0x82564557UL) /* The disk magic number */
489 #define BSD_MAXPARTITIONS 16
490 #define OPENBSD_MAXPARTITIONS 16
491 #define BSD_FS_UNUSED 0 /* disklabel unused partition entry ID */
492 struct bsd_disklabel {
493 __le32 d_magic; /* the magic number */
494 __s16 d_type; /* drive type */
495 __s16 d_subtype; /* controller/d_type specific */
496 char d_typename[16]; /* type name, e.g. "eagle" */
497 char d_packname[16]; /* pack identifier */
498 __u32 d_secsize; /* # of bytes per sector */
499 __u32 d_nsectors; /* # of data sectors per track */
500 __u32 d_ntracks; /* # of tracks per cylinder */
501 __u32 d_ncylinders; /* # of data cylinders per unit */
502 __u32 d_secpercyl; /* # of data sectors per cylinder */
503 __u32 d_secperunit; /* # of data sectors per unit */
504 __u16 d_sparespertrack; /* # of spare sectors per track */
505 __u16 d_sparespercyl; /* # of spare sectors per cylinder */
506 __u32 d_acylinders; /* # of alt. cylinders per unit */
507 __u16 d_rpm; /* rotational speed */
508 __u16 d_interleave; /* hardware sector interleave */
509 __u16 d_trackskew; /* sector 0 skew, per track */
510 __u16 d_cylskew; /* sector 0 skew, per cylinder */
511 __u32 d_headswitch; /* head switch time, usec */
512 __u32 d_trkseek; /* track-to-track seek, usec */
513 __u32 d_flags; /* generic flags */
515 __u32 d_drivedata[NDDATA]; /* drive-type specific information */
517 __u32 d_spare[NSPARE]; /* reserved for future use */
518 __le32 d_magic2; /* the magic number (again) */
519 __le16 d_checksum; /* xor of data incl. partitions */
521 /* filesystem and partition information: */
522 __le16 d_npartitions; /* number of partitions in following */
523 __le32 d_bbsize; /* size of boot area at sn0, bytes */
524 __le32 d_sbsize; /* max size of fs superblock, bytes */
525 struct bsd_partition { /* the partition table */
526 __le32 p_size; /* number of sectors in partition */
527 __le32 p_offset; /* starting sector */
528 __le32 p_fsize; /* filesystem basic fragment size */
529 __u8 p_fstype; /* filesystem type, see below */
530 __u8 p_frag; /* filesystem fragments per block */
531 __le16 p_cpg; /* filesystem cylinders per group */
532 } d_partitions[BSD_MAXPARTITIONS]; /* actually may be more */
535 #endif /* CONFIG_BSD_DISKLABEL */
537 #ifdef CONFIG_UNIXWARE_DISKLABEL
539 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
540 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
543 #define UNIXWARE_DISKMAGIC (0xCA5E600DUL) /* The disk magic number */
544 #define UNIXWARE_DISKMAGIC2 (0x600DDEEEUL) /* The slice table magic nr */
545 #define UNIXWARE_NUMSLICE 16
546 #define UNIXWARE_FS_UNUSED 0 /* Unused slice entry ID */
548 struct unixware_slice {
549 __le16 s_label; /* label */
550 __le16 s_flags; /* permission flags */
551 __le32 start_sect; /* starting sector */
552 __le32 nr_sects; /* number of sectors in slice */
555 struct unixware_disklabel {
556 __le32 d_type; /* drive type */
557 __le32 d_magic; /* the magic number */
558 __le32 d_version; /* version number */
559 char d_serial[12]; /* serial number of the device */
560 __le32 d_ncylinders; /* # of data cylinders per device */
561 __le32 d_ntracks; /* # of tracks per cylinder */
562 __le32 d_nsectors; /* # of data sectors per track */
563 __le32 d_secsize; /* # of bytes per sector */
564 __le32 d_part_start; /* # of first sector of this partition */
565 __le32 d_unknown1[12]; /* ? */
566 __le32 d_alt_tbl; /* byte offset of alternate table */
567 __le32 d_alt_len; /* byte length of alternate table */
568 __le32 d_phys_cyl; /* # of physical cylinders per device */
569 __le32 d_phys_trk; /* # of physical tracks per cylinder */
570 __le32 d_phys_sec; /* # of physical sectors per track */
571 __le32 d_phys_bytes; /* # of physical bytes per sector */
572 __le32 d_unknown2; /* ? */
573 __le32 d_unknown3; /* ? */
574 __le32 d_pad[8]; /* pad */
576 struct unixware_vtoc {
577 __le32 v_magic; /* the magic number */
578 __le32 v_version; /* version number */
579 char v_name[8]; /* volume name */
580 __le16 v_nslices; /* # of slices */
581 __le16 v_unknown1; /* ? */
582 __le32 v_reserved[10]; /* reserved */
583 struct unixware_slice
584 v_slice[UNIXWARE_NUMSLICE]; /* slice headers */
589 #endif /* CONFIG_UNIXWARE_DISKLABEL */
591 #ifdef CONFIG_MINIX_SUBPARTITION
592 # define MINIX_NR_SUBPARTITIONS 4
593 #endif /* CONFIG_MINIX_SUBPARTITION */
595 #define ADDPART_FLAG_NONE 0
596 #define ADDPART_FLAG_RAID 1
597 #define ADDPART_FLAG_WHOLEDISK 2
599 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
600 extern void blk_free_devt(dev_t devt);
601 extern dev_t blk_lookup_devt(const char *name, int partno);
602 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
604 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
605 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
606 extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
607 extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
608 int partno, sector_t start,
609 sector_t len, int flags,
610 struct partition_meta_info
612 extern void __delete_partition(struct percpu_ref *);
613 extern void delete_partition(struct gendisk *, int);
614 extern void printk_all_partitions(void);
616 extern struct gendisk *alloc_disk_node(int minors, int node_id);
617 extern struct gendisk *alloc_disk(int minors);
618 extern struct kobject *get_disk(struct gendisk *disk);
619 extern void put_disk(struct gendisk *disk);
620 extern void blk_register_region(dev_t devt, unsigned long range,
621 struct module *module,
622 struct kobject *(*probe)(dev_t, int *, void *),
623 int (*lock)(dev_t, void *),
625 extern void blk_unregister_region(dev_t devt, unsigned long range);
627 extern ssize_t part_size_show(struct device *dev,
628 struct device_attribute *attr, char *buf);
629 extern ssize_t part_stat_show(struct device *dev,
630 struct device_attribute *attr, char *buf);
631 extern ssize_t part_inflight_show(struct device *dev,
632 struct device_attribute *attr, char *buf);
633 #ifdef CONFIG_FAIL_MAKE_REQUEST
634 extern ssize_t part_fail_show(struct device *dev,
635 struct device_attribute *attr, char *buf);
636 extern ssize_t part_fail_store(struct device *dev,
637 struct device_attribute *attr,
638 const char *buf, size_t count);
639 #endif /* CONFIG_FAIL_MAKE_REQUEST */
641 static inline int hd_ref_init(struct hd_struct *part)
643 if (percpu_ref_init(&part->ref, __delete_partition, 0,
649 static inline void hd_struct_get(struct hd_struct *part)
651 percpu_ref_get(&part->ref);
654 static inline int hd_struct_try_get(struct hd_struct *part)
656 return percpu_ref_tryget_live(&part->ref);
659 static inline void hd_struct_put(struct hd_struct *part)
661 percpu_ref_put(&part->ref);
664 static inline void hd_struct_kill(struct hd_struct *part)
666 percpu_ref_kill(&part->ref);
669 static inline void hd_free_part(struct hd_struct *part)
671 free_part_stats(part);
672 free_part_info(part);
673 percpu_ref_exit(&part->ref);
677 * Any access of part->nr_sects which is not protected by partition
678 * bd_mutex or gendisk bdev bd_mutex, should be done using this
681 * Code written along the lines of i_size_read() and i_size_write().
682 * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
685 static inline sector_t part_nr_sects_read(struct hd_struct *part)
687 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
691 seq = read_seqcount_begin(&part->nr_sects_seq);
692 nr_sects = part->nr_sects;
693 } while (read_seqcount_retry(&part->nr_sects_seq, seq));
695 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
699 nr_sects = part->nr_sects;
703 return part->nr_sects;
708 * Should be called with mutex lock held (typically bd_mutex) of partition
709 * to provide mutual exlusion among writers otherwise seqcount might be
710 * left in wrong state leaving the readers spinning infinitely.
712 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
714 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
715 write_seqcount_begin(&part->nr_sects_seq);
716 part->nr_sects = size;
717 write_seqcount_end(&part->nr_sects_seq);
718 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
720 part->nr_sects = size;
723 part->nr_sects = size;
727 #if defined(CONFIG_BLK_DEV_INTEGRITY)
728 extern void blk_integrity_add(struct gendisk *);
729 extern void blk_integrity_del(struct gendisk *);
730 extern void blk_integrity_revalidate(struct gendisk *);
731 #else /* CONFIG_BLK_DEV_INTEGRITY */
732 static inline void blk_integrity_add(struct gendisk *disk) { }
733 static inline void blk_integrity_del(struct gendisk *disk) { }
734 static inline void blk_integrity_revalidate(struct gendisk *disk) { }
735 #endif /* CONFIG_BLK_DEV_INTEGRITY */
737 #else /* CONFIG_BLOCK */
739 static inline void printk_all_partitions(void) { }
741 static inline dev_t blk_lookup_devt(const char *name, int partno)
743 dev_t devt = MKDEV(0, 0);
747 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
751 #endif /* CONFIG_BLOCK */
753 #endif /* _LINUX_GENHD_H */