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>
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
;
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>
66 #include <linux/workqueue.h>
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
));
82 unsigned long sectors
[2]; /* READs and WRITEs */
84 unsigned long merges
[2];
85 unsigned long ticks
[2];
86 unsigned long io_ticks
;
87 unsigned long time_in_queue
;
90 #define PARTITION_META_INFO_VOLNAMELTH 64
92 * Enough for the string representation of any kind of UUID plus NULL.
93 * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
95 #define PARTITION_META_INFO_UUIDLTH 37
97 struct partition_meta_info
{
98 char uuid
[PARTITION_META_INFO_UUIDLTH
];
99 u8 volname
[PARTITION_META_INFO_VOLNAMELTH
];
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.
110 seqcount_t nr_sects_seq
;
111 sector_t alignment_offset
;
112 unsigned int discard_alignment
;
114 struct kobject
*holder_dir
;
116 struct partition_meta_info
*info
;
117 #ifdef CONFIG_FAIL_MAKE_REQUEST
121 atomic_t in_flight
[2];
123 struct disk_stats __percpu
*dkstats
;
125 struct disk_stats dkstats
;
128 struct rcu_head rcu_head
;
131 #define GENHD_FL_REMOVABLE 1
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
143 DISK_EVENT_MEDIA_CHANGE
= 1 << 0, /* media changed */
144 DISK_EVENT_EJECT_REQUEST
= 1 << 1, /* eject requested */
147 #define BLK_SCSI_MAX_CMDS (256)
148 #define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
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
];
156 struct disk_part_tbl
{
157 struct rcu_head rcu_head
;
159 struct hd_struct __rcu
*last_lookup
;
160 struct hd_struct __rcu
*part
[];
166 /* major, first_minor and minors are input parameters only,
167 * don't use directly. Use disk_devt() and disk_max_parts().
169 int major
; /* major number of driver */
171 int minors
; /* maximum number of minors, =1 for
172 * disks that can't be partitioned. */
174 char disk_name
[DISK_NAME_LEN
]; /* name of major driver */
175 char *(*devnode
)(struct gendisk
*gd
, umode_t
*mode
);
177 unsigned int events
; /* supported events */
178 unsigned int async_events
; /* async events, subset of all */
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
185 struct disk_part_tbl __rcu
*part_tbl
;
186 struct hd_struct part0
;
188 const struct block_device_operations
*fops
;
189 struct request_queue
*queue
;
193 struct device
*driverfs_dev
; // FIXME: remove
194 struct kobject
*slave_dir
;
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
;
205 static inline struct gendisk
*part_to_disk(struct hd_struct
*part
)
209 return dev_to_disk(part_to_dev(part
)->parent
);
211 return dev_to_disk(part_to_dev(part
));
216 static inline void part_pack_uuid(const u8
*uuid_str
, u8
*to
)
219 for (i
= 0; i
< 16; ++i
) {
220 *to
++ = (hex_to_bin(*uuid_str
) << 4) |
221 (hex_to_bin(*(uuid_str
+ 1)));
234 static inline int disk_max_parts(struct gendisk
*disk
)
236 if (disk
->flags
& GENHD_FL_EXT_DEVT
)
237 return DISK_MAX_PARTS
;
241 static inline bool disk_part_scan_enabled(struct gendisk
*disk
)
243 return disk_max_parts(disk
) > 1 &&
244 !(disk
->flags
& GENHD_FL_NO_PART_SCAN
);
247 static inline dev_t
disk_devt(struct gendisk
*disk
)
249 return disk_to_dev(disk
)->devt
;
252 static inline dev_t
part_devt(struct hd_struct
*part
)
254 return part_to_dev(part
)->devt
;
257 extern struct hd_struct
*disk_get_part(struct gendisk
*disk
, int partno
);
259 static inline void disk_put_part(struct hd_struct
*part
)
262 put_device(part_to_dev(part
));
266 * Smarter partition iterator without context limits.
268 #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */
269 #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */
270 #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */
271 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
273 struct disk_part_iter
{
274 struct gendisk
*disk
;
275 struct hd_struct
*part
;
280 extern void disk_part_iter_init(struct disk_part_iter
*piter
,
281 struct gendisk
*disk
, unsigned int flags
);
282 extern struct hd_struct
*disk_part_iter_next(struct disk_part_iter
*piter
);
283 extern void disk_part_iter_exit(struct disk_part_iter
*piter
);
285 extern struct hd_struct
*disk_map_sector_rcu(struct gendisk
*disk
,
289 * Macros to operate on percpu disk statistics:
291 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
292 * and should be called between disk_stat_lock() and
293 * disk_stat_unlock().
295 * part_stat_read() can be called at any time.
297 * part_stat_{add|set_all}() and {init|free}_part_stats are for
301 #define part_stat_lock() ({ rcu_read_lock(); get_cpu(); })
302 #define part_stat_unlock() do { put_cpu(); rcu_read_unlock(); } while (0)
304 #define __part_stat_add(cpu, part, field, addnd) \
305 (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
307 #define part_stat_read(part, field) \
309 typeof((part)->dkstats->field) res = 0; \
311 for_each_possible_cpu(_cpu) \
312 res += per_cpu_ptr((part)->dkstats, _cpu)->field; \
316 static inline void part_stat_set_all(struct hd_struct
*part
, int value
)
320 for_each_possible_cpu(i
)
321 memset(per_cpu_ptr(part
->dkstats
, i
), value
,
322 sizeof(struct disk_stats
));
325 static inline int init_part_stats(struct hd_struct
*part
)
327 part
->dkstats
= alloc_percpu(struct disk_stats
);
333 static inline void free_part_stats(struct hd_struct
*part
)
335 free_percpu(part
->dkstats
);
338 #else /* !CONFIG_SMP */
339 #define part_stat_lock() ({ rcu_read_lock(); 0; })
340 #define part_stat_unlock() rcu_read_unlock()
342 #define __part_stat_add(cpu, part, field, addnd) \
343 ((part)->dkstats.field += addnd)
345 #define part_stat_read(part, field) ((part)->dkstats.field)
347 static inline void part_stat_set_all(struct hd_struct
*part
, int value
)
349 memset(&part
->dkstats
, value
, sizeof(struct disk_stats
));
352 static inline int init_part_stats(struct hd_struct
*part
)
357 static inline void free_part_stats(struct hd_struct
*part
)
361 #endif /* CONFIG_SMP */
363 #define part_stat_add(cpu, part, field, addnd) do { \
364 __part_stat_add((cpu), (part), field, addnd); \
365 if ((part)->partno) \
366 __part_stat_add((cpu), &part_to_disk((part))->part0, \
370 #define part_stat_dec(cpu, gendiskp, field) \
371 part_stat_add(cpu, gendiskp, field, -1)
372 #define part_stat_inc(cpu, gendiskp, field) \
373 part_stat_add(cpu, gendiskp, field, 1)
374 #define part_stat_sub(cpu, gendiskp, field, subnd) \
375 part_stat_add(cpu, gendiskp, field, -subnd)
377 static inline void part_inc_in_flight(struct hd_struct
*part
, int rw
)
379 atomic_inc(&part
->in_flight
[rw
]);
381 atomic_inc(&part_to_disk(part
)->part0
.in_flight
[rw
]);
384 static inline void part_dec_in_flight(struct hd_struct
*part
, int rw
)
386 atomic_dec(&part
->in_flight
[rw
]);
388 atomic_dec(&part_to_disk(part
)->part0
.in_flight
[rw
]);
391 static inline int part_in_flight(struct hd_struct
*part
)
393 return atomic_read(&part
->in_flight
[0]) + atomic_read(&part
->in_flight
[1]);
396 static inline struct partition_meta_info
*alloc_part_info(struct gendisk
*disk
)
399 return kzalloc_node(sizeof(struct partition_meta_info
),
400 GFP_KERNEL
, disk
->node_id
);
401 return kzalloc(sizeof(struct partition_meta_info
), GFP_KERNEL
);
404 static inline void free_part_info(struct hd_struct
*part
)
409 /* block/blk-core.c */
410 extern void part_round_stats(int cpu
, struct hd_struct
*part
);
413 extern void add_disk(struct gendisk
*disk
);
414 extern void del_gendisk(struct gendisk
*gp
);
415 extern struct gendisk
*get_gendisk(dev_t dev
, int *partno
);
416 extern struct block_device
*bdget_disk(struct gendisk
*disk
, int partno
);
418 extern void set_device_ro(struct block_device
*bdev
, int flag
);
419 extern void set_disk_ro(struct gendisk
*disk
, int flag
);
421 static inline int get_disk_ro(struct gendisk
*disk
)
423 return disk
->part0
.policy
;
426 extern void disk_block_events(struct gendisk
*disk
);
427 extern void disk_unblock_events(struct gendisk
*disk
);
428 extern void disk_flush_events(struct gendisk
*disk
, unsigned int mask
);
429 extern unsigned int disk_clear_events(struct gendisk
*disk
, unsigned int mask
);
431 /* drivers/char/random.c */
432 extern void add_disk_randomness(struct gendisk
*disk
);
433 extern void rand_initialize_disk(struct gendisk
*disk
);
435 static inline sector_t
get_start_sect(struct block_device
*bdev
)
437 return bdev
->bd_part
->start_sect
;
439 static inline sector_t
get_capacity(struct gendisk
*disk
)
441 return disk
->part0
.nr_sects
;
443 static inline void set_capacity(struct gendisk
*disk
, sector_t size
)
445 disk
->part0
.nr_sects
= size
;
448 #ifdef CONFIG_SOLARIS_X86_PARTITION
450 #define SOLARIS_X86_NUMSLICE 16
451 #define SOLARIS_X86_VTOC_SANE (0x600DDEEEUL)
453 struct solaris_x86_slice
{
454 __le16 s_tag
; /* ID tag of partition */
455 __le16 s_flag
; /* permission flags */
456 __le32 s_start
; /* start sector no of partition */
457 __le32 s_size
; /* # of blocks in partition */
460 struct solaris_x86_vtoc
{
461 unsigned int v_bootinfo
[3]; /* info needed by mboot (unsupported) */
462 __le32 v_sanity
; /* to verify vtoc sanity */
463 __le32 v_version
; /* layout version */
464 char v_volume
[8]; /* volume name */
465 __le16 v_sectorsz
; /* sector size in bytes */
466 __le16 v_nparts
; /* number of partitions */
467 unsigned int v_reserved
[10]; /* free space */
468 struct solaris_x86_slice
469 v_slice
[SOLARIS_X86_NUMSLICE
]; /* slice headers */
470 unsigned int timestamp
[SOLARIS_X86_NUMSLICE
]; /* timestamp (unsupported) */
471 char v_asciilabel
[128]; /* for compatibility */
474 #endif /* CONFIG_SOLARIS_X86_PARTITION */
476 #ifdef CONFIG_BSD_DISKLABEL
478 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
479 * updated by Marc Espie <Marc.Espie@openbsd.org>
482 /* check against BSD src/sys/sys/disklabel.h for consistency */
484 #define BSD_DISKMAGIC (0x82564557UL) /* The disk magic number */
485 #define BSD_MAXPARTITIONS 16
486 #define OPENBSD_MAXPARTITIONS 16
487 #define BSD_FS_UNUSED 0 /* disklabel unused partition entry ID */
488 struct bsd_disklabel
{
489 __le32 d_magic
; /* the magic number */
490 __s16 d_type
; /* drive type */
491 __s16 d_subtype
; /* controller/d_type specific */
492 char d_typename
[16]; /* type name, e.g. "eagle" */
493 char d_packname
[16]; /* pack identifier */
494 __u32 d_secsize
; /* # of bytes per sector */
495 __u32 d_nsectors
; /* # of data sectors per track */
496 __u32 d_ntracks
; /* # of tracks per cylinder */
497 __u32 d_ncylinders
; /* # of data cylinders per unit */
498 __u32 d_secpercyl
; /* # of data sectors per cylinder */
499 __u32 d_secperunit
; /* # of data sectors per unit */
500 __u16 d_sparespertrack
; /* # of spare sectors per track */
501 __u16 d_sparespercyl
; /* # of spare sectors per cylinder */
502 __u32 d_acylinders
; /* # of alt. cylinders per unit */
503 __u16 d_rpm
; /* rotational speed */
504 __u16 d_interleave
; /* hardware sector interleave */
505 __u16 d_trackskew
; /* sector 0 skew, per track */
506 __u16 d_cylskew
; /* sector 0 skew, per cylinder */
507 __u32 d_headswitch
; /* head switch time, usec */
508 __u32 d_trkseek
; /* track-to-track seek, usec */
509 __u32 d_flags
; /* generic flags */
511 __u32 d_drivedata
[NDDATA
]; /* drive-type specific information */
513 __u32 d_spare
[NSPARE
]; /* reserved for future use */
514 __le32 d_magic2
; /* the magic number (again) */
515 __le16 d_checksum
; /* xor of data incl. partitions */
517 /* filesystem and partition information: */
518 __le16 d_npartitions
; /* number of partitions in following */
519 __le32 d_bbsize
; /* size of boot area at sn0, bytes */
520 __le32 d_sbsize
; /* max size of fs superblock, bytes */
521 struct bsd_partition
{ /* the partition table */
522 __le32 p_size
; /* number of sectors in partition */
523 __le32 p_offset
; /* starting sector */
524 __le32 p_fsize
; /* filesystem basic fragment size */
525 __u8 p_fstype
; /* filesystem type, see below */
526 __u8 p_frag
; /* filesystem fragments per block */
527 __le16 p_cpg
; /* filesystem cylinders per group */
528 } d_partitions
[BSD_MAXPARTITIONS
]; /* actually may be more */
531 #endif /* CONFIG_BSD_DISKLABEL */
533 #ifdef CONFIG_UNIXWARE_DISKLABEL
535 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
536 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
539 #define UNIXWARE_DISKMAGIC (0xCA5E600DUL) /* The disk magic number */
540 #define UNIXWARE_DISKMAGIC2 (0x600DDEEEUL) /* The slice table magic nr */
541 #define UNIXWARE_NUMSLICE 16
542 #define UNIXWARE_FS_UNUSED 0 /* Unused slice entry ID */
544 struct unixware_slice
{
545 __le16 s_label
; /* label */
546 __le16 s_flags
; /* permission flags */
547 __le32 start_sect
; /* starting sector */
548 __le32 nr_sects
; /* number of sectors in slice */
551 struct unixware_disklabel
{
552 __le32 d_type
; /* drive type */
553 __le32 d_magic
; /* the magic number */
554 __le32 d_version
; /* version number */
555 char d_serial
[12]; /* serial number of the device */
556 __le32 d_ncylinders
; /* # of data cylinders per device */
557 __le32 d_ntracks
; /* # of tracks per cylinder */
558 __le32 d_nsectors
; /* # of data sectors per track */
559 __le32 d_secsize
; /* # of bytes per sector */
560 __le32 d_part_start
; /* # of first sector of this partition */
561 __le32 d_unknown1
[12]; /* ? */
562 __le32 d_alt_tbl
; /* byte offset of alternate table */
563 __le32 d_alt_len
; /* byte length of alternate table */
564 __le32 d_phys_cyl
; /* # of physical cylinders per device */
565 __le32 d_phys_trk
; /* # of physical tracks per cylinder */
566 __le32 d_phys_sec
; /* # of physical sectors per track */
567 __le32 d_phys_bytes
; /* # of physical bytes per sector */
568 __le32 d_unknown2
; /* ? */
569 __le32 d_unknown3
; /* ? */
570 __le32 d_pad
[8]; /* pad */
572 struct unixware_vtoc
{
573 __le32 v_magic
; /* the magic number */
574 __le32 v_version
; /* version number */
575 char v_name
[8]; /* volume name */
576 __le16 v_nslices
; /* # of slices */
577 __le16 v_unknown1
; /* ? */
578 __le32 v_reserved
[10]; /* reserved */
579 struct unixware_slice
580 v_slice
[UNIXWARE_NUMSLICE
]; /* slice headers */
585 #endif /* CONFIG_UNIXWARE_DISKLABEL */
587 #ifdef CONFIG_MINIX_SUBPARTITION
588 # define MINIX_NR_SUBPARTITIONS 4
589 #endif /* CONFIG_MINIX_SUBPARTITION */
591 #define ADDPART_FLAG_NONE 0
592 #define ADDPART_FLAG_RAID 1
593 #define ADDPART_FLAG_WHOLEDISK 2
595 extern int blk_alloc_devt(struct hd_struct
*part
, dev_t
*devt
);
596 extern void blk_free_devt(dev_t devt
);
597 extern dev_t
blk_lookup_devt(const char *name
, int partno
);
598 extern char *disk_name (struct gendisk
*hd
, int partno
, char *buf
);
600 extern int disk_expand_part_tbl(struct gendisk
*disk
, int target
);
601 extern int rescan_partitions(struct gendisk
*disk
, struct block_device
*bdev
);
602 extern int invalidate_partitions(struct gendisk
*disk
, struct block_device
*bdev
);
603 extern struct hd_struct
* __must_check
add_partition(struct gendisk
*disk
,
604 int partno
, sector_t start
,
605 sector_t len
, int flags
,
606 struct partition_meta_info
608 extern void __delete_partition(struct hd_struct
*);
609 extern void delete_partition(struct gendisk
*, int);
610 extern void printk_all_partitions(void);
612 extern struct gendisk
*alloc_disk_node(int minors
, int node_id
);
613 extern struct gendisk
*alloc_disk(int minors
);
614 extern struct kobject
*get_disk(struct gendisk
*disk
);
615 extern void put_disk(struct gendisk
*disk
);
616 extern void blk_register_region(dev_t devt
, unsigned long range
,
617 struct module
*module
,
618 struct kobject
*(*probe
)(dev_t
, int *, void *),
619 int (*lock
)(dev_t
, void *),
621 extern void blk_unregister_region(dev_t devt
, unsigned long range
);
623 extern ssize_t
part_size_show(struct device
*dev
,
624 struct device_attribute
*attr
, char *buf
);
625 extern ssize_t
part_stat_show(struct device
*dev
,
626 struct device_attribute
*attr
, char *buf
);
627 extern ssize_t
part_inflight_show(struct device
*dev
,
628 struct device_attribute
*attr
, char *buf
);
629 #ifdef CONFIG_FAIL_MAKE_REQUEST
630 extern ssize_t
part_fail_show(struct device
*dev
,
631 struct device_attribute
*attr
, char *buf
);
632 extern ssize_t
part_fail_store(struct device
*dev
,
633 struct device_attribute
*attr
,
634 const char *buf
, size_t count
);
635 #endif /* CONFIG_FAIL_MAKE_REQUEST */
637 static inline void hd_ref_init(struct hd_struct
*part
)
639 atomic_set(&part
->ref
, 1);
643 static inline void hd_struct_get(struct hd_struct
*part
)
645 atomic_inc(&part
->ref
);
646 smp_mb__after_atomic_inc();
649 static inline int hd_struct_try_get(struct hd_struct
*part
)
651 return atomic_inc_not_zero(&part
->ref
);
654 static inline void hd_struct_put(struct hd_struct
*part
)
656 if (atomic_dec_and_test(&part
->ref
))
657 __delete_partition(part
);
661 * Any access of part->nr_sects which is not protected by partition
662 * bd_mutex or gendisk bdev bd_mutex, should be done using this
665 * Code written along the lines of i_size_read() and i_size_write().
666 * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
669 static inline sector_t
part_nr_sects_read(struct hd_struct
*part
)
671 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
675 seq
= read_seqcount_begin(&part
->nr_sects_seq
);
676 nr_sects
= part
->nr_sects
;
677 } while (read_seqcount_retry(&part
->nr_sects_seq
, seq
));
679 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
683 nr_sects
= part
->nr_sects
;
687 return part
->nr_sects
;
692 * Should be called with mutex lock held (typically bd_mutex) of partition
693 * to provide mutual exlusion among writers otherwise seqcount might be
694 * left in wrong state leaving the readers spinning infinitely.
696 static inline void part_nr_sects_write(struct hd_struct
*part
, sector_t size
)
698 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
699 write_seqcount_begin(&part
->nr_sects_seq
);
700 part
->nr_sects
= size
;
701 write_seqcount_end(&part
->nr_sects_seq
);
702 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
704 part
->nr_sects
= size
;
707 part
->nr_sects
= size
;
711 #else /* CONFIG_BLOCK */
713 static inline void printk_all_partitions(void) { }
715 static inline dev_t
blk_lookup_devt(const char *name
, int partno
)
717 dev_t devt
= MKDEV(0, 0);
721 #endif /* CONFIG_BLOCK */
723 #endif /* _LINUX_GENHD_H */