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Diffstat (limited to 'include/linux/genhd.h')
| -rw-r--r-- | include/linux/genhd.h | 733 |
1 files changed, 733 insertions, 0 deletions
diff --git a/include/linux/genhd.h b/include/linux/genhd.h new file mode 100644 index 000000000..ec274e0f4 --- /dev/null +++ b/include/linux/genhd.h @@ -0,0 +1,733 @@ +#ifndef _LINUX_GENHD_H +#define _LINUX_GENHD_H + +/* + * genhd.h Copyright (C) 1992 Drew Eckhardt + * Generic hard disk header file by + * Drew Eckhardt + * + * <drew@colorado.edu> + */ + +#include <linux/types.h> +#include <linux/kdev_t.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> + +#ifdef CONFIG_BLOCK + +#define dev_to_disk(device) container_of((device), struct gendisk, part0.__dev) +#define dev_to_part(device) container_of((device), struct hd_struct, __dev) +#define disk_to_dev(disk) (&(disk)->part0.__dev) +#define part_to_dev(part) (&((part)->__dev)) + +extern struct device_type part_type; +extern struct kobject *block_depr; +extern struct class block_class; + +enum { +/* These three have identical behaviour; use the second one if DOS FDISK gets + confused about extended/logical partitions starting past cylinder 1023. */ + DOS_EXTENDED_PARTITION = 5, + LINUX_EXTENDED_PARTITION = 0x85, + WIN98_EXTENDED_PARTITION = 0x0f, + + SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION, + + LINUX_SWAP_PARTITION = 0x82, + LINUX_DATA_PARTITION = 0x83, + LINUX_LVM_PARTITION = 0x8e, + LINUX_RAID_PARTITION = 0xfd, /* autodetect RAID partition */ + + SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION, + NEW_SOLARIS_X86_PARTITION = 0xbf, + + DM6_AUX1PARTITION = 0x51, /* no DDO: use xlated geom */ + DM6_AUX3PARTITION = 0x53, /* no DDO: use xlated geom */ + DM6_PARTITION = 0x54, /* has DDO: use xlated geom & offset */ + EZD_PARTITION = 0x55, /* EZ-DRIVE */ + + FREEBSD_PARTITION = 0xa5, /* FreeBSD Partition ID */ + OPENBSD_PARTITION = 0xa6, /* OpenBSD Partition ID */ + NETBSD_PARTITION = 0xa9, /* NetBSD Partition ID */ + BSDI_PARTITION = 0xb7, /* BSDI Partition ID */ + MINIX_PARTITION = 0x81, /* Minix Partition ID */ + UNIXWARE_PARTITION = 0x63, /* Same as GNU_HURD and SCO Unix */ +}; + +#define DISK_MAX_PARTS 256 +#define DISK_NAME_LEN 32 + +#include <linux/major.h> +#include <linux/device.h> +#include <linux/smp.h> +#include <linux/string.h> +#include <linux/fs.h> +#include <linux/workqueue.h> + +struct partition { + unsigned char boot_ind; /* 0x80 - active */ + unsigned char head; /* starting head */ + unsigned char sector; /* starting sector */ + unsigned char cyl; /* starting cylinder */ + unsigned char sys_ind; /* What partition type */ + unsigned char end_head; /* end head */ + unsigned char end_sector; /* end sector */ + unsigned char end_cyl; /* end cylinder */ + __le32 start_sect; /* starting sector counting from 0 */ + __le32 nr_sects; /* nr of sectors in partition */ +} __attribute__((packed)); + +struct disk_stats { + unsigned long sectors[2]; /* READs and WRITEs */ + unsigned long ios[2]; + unsigned long merges[2]; + unsigned long ticks[2]; + unsigned long io_ticks; + unsigned long time_in_queue; +}; + +#define PARTITION_META_INFO_VOLNAMELTH 64 +/* + * Enough for the string representation of any kind of UUID plus NULL. + * EFI UUID is 36 characters. MSDOS UUID is 11 characters. + */ +#define PARTITION_META_INFO_UUIDLTH 37 + +struct partition_meta_info { + char uuid[PARTITION_META_INFO_UUIDLTH]; + u8 volname[PARTITION_META_INFO_VOLNAMELTH]; +}; + +struct hd_struct { + sector_t start_sect; + /* + * nr_sects is protected by sequence counter. One might extend a + * partition while IO is happening to it and update of nr_sects + * can be non-atomic on 32bit machines with 64bit sector_t. + */ + sector_t nr_sects; + seqcount_t nr_sects_seq; + sector_t alignment_offset; + unsigned int discard_alignment; + struct device __dev; + struct kobject *holder_dir; + int policy, partno; + struct partition_meta_info *info; +#ifdef CONFIG_FAIL_MAKE_REQUEST + int make_it_fail; +#endif + unsigned long stamp; + atomic_t in_flight[2]; +#ifdef CONFIG_SMP + struct disk_stats __percpu *dkstats; +#else + struct disk_stats dkstats; +#endif + atomic_t ref; + struct rcu_head rcu_head; +}; + +#define GENHD_FL_REMOVABLE 1 +/* 2 is unused */ +#define GENHD_FL_MEDIA_CHANGE_NOTIFY 4 +#define GENHD_FL_CD 8 +#define GENHD_FL_UP 16 +#define GENHD_FL_SUPPRESS_PARTITION_INFO 32 +#define GENHD_FL_EXT_DEVT 64 /* allow extended devt */ +#define GENHD_FL_NATIVE_CAPACITY 128 +#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256 +#define GENHD_FL_NO_PART_SCAN 512 + +enum { + DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */ + DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */ +}; + +#define BLK_SCSI_MAX_CMDS (256) +#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) + +struct blk_scsi_cmd_filter { + unsigned long read_ok[BLK_SCSI_CMD_PER_LONG]; + unsigned long write_ok[BLK_SCSI_CMD_PER_LONG]; + struct kobject kobj; +}; + +struct disk_part_tbl { + struct rcu_head rcu_head; + int len; + struct hd_struct __rcu *last_lookup; + struct hd_struct __rcu *part[]; +}; + +struct disk_events; + +struct gendisk { + /* major, first_minor and minors are input parameters only, + * don't use directly. Use disk_devt() and disk_max_parts(). + */ + int major; /* major number of driver */ + int first_minor; + int minors; /* maximum number of minors, =1 for + * disks that can't be partitioned. */ + + char disk_name[DISK_NAME_LEN]; /* name of major driver */ + char *(*devnode)(struct gendisk *gd, umode_t *mode); + + unsigned int events; /* supported events */ + unsigned int async_events; /* async events, subset of all */ + + /* Array of pointers to partitions indexed by partno. + * Protected with matching bdev lock but stat and other + * non-critical accesses use RCU. Always access through + * helpers. + */ + struct disk_part_tbl __rcu *part_tbl; + struct hd_struct part0; + + const struct block_device_operations *fops; + struct request_queue *queue; + void *private_data; + + int flags; + struct device *driverfs_dev; // FIXME: remove + struct kobject *slave_dir; + + struct timer_rand_state *random; + atomic_t sync_io; /* RAID */ + struct disk_events *ev; +#ifdef CONFIG_BLK_DEV_INTEGRITY + struct blk_integrity *integrity; +#endif + int node_id; +}; + +static inline struct gendisk *part_to_disk(struct hd_struct *part) +{ + if (likely(part)) { + if (part->partno) + return dev_to_disk(part_to_dev(part)->parent); + else + return dev_to_disk(part_to_dev(part)); + } + return NULL; +} + +static inline void part_pack_uuid(const u8 *uuid_str, u8 *to) +{ + int i; + for (i = 0; i < 16; ++i) { + *to++ = (hex_to_bin(*uuid_str) << 4) | + (hex_to_bin(*(uuid_str + 1))); + uuid_str += 2; + switch (i) { + case 3: + case 5: + case 7: + case 9: + uuid_str++; + continue; + } + } +} + +static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to) +{ + part_pack_uuid(uuid_str, to); + return 0; +} + +static inline int disk_max_parts(struct gendisk *disk) +{ + if (disk->flags & GENHD_FL_EXT_DEVT) + return DISK_MAX_PARTS; + return disk->minors; +} + +static inline bool disk_part_scan_enabled(struct gendisk *disk) +{ + return disk_max_parts(disk) > 1 && + !(disk->flags & GENHD_FL_NO_PART_SCAN); +} + +static inline dev_t disk_devt(struct gendisk *disk) +{ + return disk_to_dev(disk)->devt; +} + +static inline dev_t part_devt(struct hd_struct *part) +{ + return part_to_dev(part)->devt; +} + +extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno); + +static inline void disk_put_part(struct hd_struct *part) +{ + if (likely(part)) + put_device(part_to_dev(part)); +} + +/* + * Smarter partition iterator without context limits. + */ +#define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */ +#define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */ +#define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */ +#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */ + +struct disk_part_iter { + struct gendisk *disk; + struct hd_struct *part; + int idx; + unsigned int flags; +}; + +extern void disk_part_iter_init(struct disk_part_iter *piter, + struct gendisk *disk, unsigned int flags); +extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter); +extern void disk_part_iter_exit(struct disk_part_iter *piter); + +extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, + sector_t sector); + +/* + * Macros to operate on percpu disk statistics: + * + * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters + * and should be called between disk_stat_lock() and + * disk_stat_unlock(). + * + * part_stat_read() can be called at any time. + * + * part_stat_{add|set_all}() and {init|free}_part_stats are for + * internal use only. + */ +#ifdef CONFIG_SMP +#define part_stat_lock() ({ rcu_read_lock(); get_cpu(); }) +#define part_stat_unlock() do { put_cpu(); rcu_read_unlock(); } while (0) + +#define __part_stat_add(cpu, part, field, addnd) \ + (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd)) + +#define part_stat_read(part, field) \ +({ \ + typeof((part)->dkstats->field) res = 0; \ + unsigned int _cpu; \ + for_each_possible_cpu(_cpu) \ + res += per_cpu_ptr((part)->dkstats, _cpu)->field; \ + res; \ +}) + +static inline void part_stat_set_all(struct hd_struct *part, int value) +{ + int i; + + for_each_possible_cpu(i) + memset(per_cpu_ptr(part->dkstats, i), value, + sizeof(struct disk_stats)); +} + +static inline int init_part_stats(struct hd_struct *part) +{ + part->dkstats = alloc_percpu(struct disk_stats); + if (!part->dkstats) + return 0; + return 1; +} + +static inline void free_part_stats(struct hd_struct *part) +{ + free_percpu(part->dkstats); +} + +#else /* !CONFIG_SMP */ +#define part_stat_lock() ({ rcu_read_lock(); 0; }) +#define part_stat_unlock() rcu_read_unlock() + +#define __part_stat_add(cpu, part, field, addnd) \ + ((part)->dkstats.field += addnd) + +#define part_stat_read(part, field) ((part)->dkstats.field) + +static inline void part_stat_set_all(struct hd_struct *part, int value) +{ + memset(&part->dkstats, value, sizeof(struct disk_stats)); +} + +static inline int init_part_stats(struct hd_struct *part) +{ + return 1; +} + +static inline void free_part_stats(struct hd_struct *part) +{ +} + +#endif /* CONFIG_SMP */ + +#define part_stat_add(cpu, part, field, addnd) do { \ + __part_stat_add((cpu), (part), field, addnd); \ + if ((part)->partno) \ + __part_stat_add((cpu), &part_to_disk((part))->part0, \ + field, addnd); \ +} while (0) + +#define part_stat_dec(cpu, gendiskp, field) \ + part_stat_add(cpu, gendiskp, field, -1) +#define part_stat_inc(cpu, gendiskp, field) \ + part_stat_add(cpu, gendiskp, field, 1) +#define part_stat_sub(cpu, gendiskp, field, subnd) \ + part_stat_add(cpu, gendiskp, field, -subnd) + +static inline void part_inc_in_flight(struct hd_struct *part, int rw) +{ + atomic_inc(&part->in_flight[rw]); + if (part->partno) + atomic_inc(&part_to_disk(part)->part0.in_flight[rw]); +} + +static inline void part_dec_in_flight(struct hd_struct *part, int rw) +{ + atomic_dec(&part->in_flight[rw]); + if (part->partno) + atomic_dec(&part_to_disk(part)->part0.in_flight[rw]); +} + +static inline int part_in_flight(struct hd_struct *part) +{ + return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]); +} + +static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk) +{ + if (disk) + return kzalloc_node(sizeof(struct partition_meta_info), + GFP_KERNEL, disk->node_id); + return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL); +} + +static inline void free_part_info(struct hd_struct *part) +{ + kfree(part->info); +} + +/* block/blk-core.c */ +extern void part_round_stats(int cpu, struct hd_struct *part); + +/* block/genhd.c */ +extern void add_disk(struct gendisk *disk); +extern void del_gendisk(struct gendisk *gp); +extern struct gendisk *get_gendisk(dev_t dev, int *partno); +extern struct block_device *bdget_disk(struct gendisk *disk, int partno); + +extern void set_device_ro(struct block_device *bdev, int flag); +extern void set_disk_ro(struct gendisk *disk, int flag); + +static inline int get_disk_ro(struct gendisk *disk) +{ + return disk->part0.policy; +} + +extern void disk_block_events(struct gendisk *disk); +extern void disk_unblock_events(struct gendisk *disk); +extern void disk_flush_events(struct gendisk *disk, unsigned int mask); +extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask); + +/* drivers/char/random.c */ +extern void add_disk_randomness(struct gendisk *disk); +extern void rand_initialize_disk(struct gendisk *disk); + +static inline sector_t get_start_sect(struct block_device *bdev) +{ + return bdev->bd_part->start_sect; +} +static inline sector_t get_capacity(struct gendisk *disk) +{ + return disk->part0.nr_sects; +} +static inline void set_capacity(struct gendisk *disk, sector_t size) +{ + disk->part0.nr_sects = size; +} + +#ifdef CONFIG_SOLARIS_X86_PARTITION + +#define SOLARIS_X86_NUMSLICE 16 +#define SOLARIS_X86_VTOC_SANE (0x600DDEEEUL) + +struct solaris_x86_slice { + __le16 s_tag; /* ID tag of partition */ + __le16 s_flag; /* permission flags */ + __le32 s_start; /* start sector no of partition */ + __le32 s_size; /* # of blocks in partition */ +}; + +struct solaris_x86_vtoc { + unsigned int v_bootinfo[3]; /* info needed by mboot (unsupported) */ + __le32 v_sanity; /* to verify vtoc sanity */ + __le32 v_version; /* layout version */ + char v_volume[8]; /* volume name */ + __le16 v_sectorsz; /* sector size in bytes */ + __le16 v_nparts; /* number of partitions */ + unsigned int v_reserved[10]; /* free space */ + struct solaris_x86_slice + v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */ + unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */ + char v_asciilabel[128]; /* for compatibility */ +}; + +#endif /* CONFIG_SOLARIS_X86_PARTITION */ + +#ifdef CONFIG_BSD_DISKLABEL +/* + * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il> + * updated by Marc Espie <Marc.Espie@openbsd.org> + */ + +/* check against BSD src/sys/sys/disklabel.h for consistency */ + +#define BSD_DISKMAGIC (0x82564557UL) /* The disk magic number */ +#define BSD_MAXPARTITIONS 16 +#define OPENBSD_MAXPARTITIONS 16 +#define BSD_FS_UNUSED 0 /* disklabel unused partition entry ID */ +struct bsd_disklabel { + __le32 d_magic; /* the magic number */ + __s16 d_type; /* drive type */ + __s16 d_subtype; /* controller/d_type specific */ + char d_typename[16]; /* type name, e.g. "eagle" */ + char d_packname[16]; /* pack identifier */ + __u32 d_secsize; /* # of bytes per sector */ + __u32 d_nsectors; /* # of data sectors per track */ + __u32 d_ntracks; /* # of tracks per cylinder */ + __u32 d_ncylinders; /* # of data cylinders per unit */ + __u32 d_secpercyl; /* # of data sectors per cylinder */ + __u32 d_secperunit; /* # of data sectors per unit */ + __u16 d_sparespertrack; /* # of spare sectors per track */ + __u16 d_sparespercyl; /* # of spare sectors per cylinder */ + __u32 d_acylinders; /* # of alt. cylinders per unit */ + __u16 d_rpm; /* rotational speed */ + __u16 d_interleave; /* hardware sector interleave */ + __u16 d_trackskew; /* sector 0 skew, per track */ + __u16 d_cylskew; /* sector 0 skew, per cylinder */ + __u32 d_headswitch; /* head switch time, usec */ + __u32 d_trkseek; /* track-to-track seek, usec */ + __u32 d_flags; /* generic flags */ +#define NDDATA 5 + __u32 d_drivedata[NDDATA]; /* drive-type specific information */ +#define NSPARE 5 + __u32 d_spare[NSPARE]; /* reserved for future use */ + __le32 d_magic2; /* the magic number (again) */ + __le16 d_checksum; /* xor of data incl. partitions */ + + /* filesystem and partition information: */ + __le16 d_npartitions; /* number of partitions in following */ + __le32 d_bbsize; /* size of boot area at sn0, bytes */ + __le32 d_sbsize; /* max size of fs superblock, bytes */ + struct bsd_partition { /* the partition table */ + __le32 p_size; /* number of sectors in partition */ + __le32 p_offset; /* starting sector */ + __le32 p_fsize; /* filesystem basic fragment size */ + __u8 p_fstype; /* filesystem type, see below */ + __u8 p_frag; /* filesystem fragments per block */ + __le16 p_cpg; /* filesystem cylinders per group */ + } d_partitions[BSD_MAXPARTITIONS]; /* actually may be more */ +}; + +#endif /* CONFIG_BSD_DISKLABEL */ + +#ifdef CONFIG_UNIXWARE_DISKLABEL +/* + * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl> + * and Krzysztof G. Baranowski <kgb@knm.org.pl> + */ + +#define UNIXWARE_DISKMAGIC (0xCA5E600DUL) /* The disk magic number */ +#define UNIXWARE_DISKMAGIC2 (0x600DDEEEUL) /* The slice table magic nr */ +#define UNIXWARE_NUMSLICE 16 +#define UNIXWARE_FS_UNUSED 0 /* Unused slice entry ID */ + +struct unixware_slice { + __le16 s_label; /* label */ + __le16 s_flags; /* permission flags */ + __le32 start_sect; /* starting sector */ + __le32 nr_sects; /* number of sectors in slice */ +}; + +struct unixware_disklabel { + __le32 d_type; /* drive type */ + __le32 d_magic; /* the magic number */ + __le32 d_version; /* version number */ + char d_serial[12]; /* serial number of the device */ + __le32 d_ncylinders; /* # of data cylinders per device */ + __le32 d_ntracks; /* # of tracks per cylinder */ + __le32 d_nsectors; /* # of data sectors per track */ + __le32 d_secsize; /* # of bytes per sector */ + __le32 d_part_start; /* # of first sector of this partition */ + __le32 d_unknown1[12]; /* ? */ + __le32 d_alt_tbl; /* byte offset of alternate table */ + __le32 d_alt_len; /* byte length of alternate table */ + __le32 d_phys_cyl; /* # of physical cylinders per device */ + __le32 d_phys_trk; /* # of physical tracks per cylinder */ + __le32 d_phys_sec; /* # of physical sectors per track */ + __le32 d_phys_bytes; /* # of physical bytes per sector */ + __le32 d_unknown2; /* ? */ + __le32 d_unknown3; /* ? */ + __le32 d_pad[8]; /* pad */ + + struct unixware_vtoc { + __le32 v_magic; /* the magic number */ + __le32 v_version; /* version number */ + char v_name[8]; /* volume name */ + __le16 v_nslices; /* # of slices */ + __le16 v_unknown1; /* ? */ + __le32 v_reserved[10]; /* reserved */ + struct unixware_slice + v_slice[UNIXWARE_NUMSLICE]; /* slice headers */ + } vtoc; + +}; /* 408 */ + +#endif /* CONFIG_UNIXWARE_DISKLABEL */ + +#ifdef CONFIG_MINIX_SUBPARTITION +# define MINIX_NR_SUBPARTITIONS 4 +#endif /* CONFIG_MINIX_SUBPARTITION */ + +#define ADDPART_FLAG_NONE 0 +#define ADDPART_FLAG_RAID 1 +#define ADDPART_FLAG_WHOLEDISK 2 + +extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt); +extern void blk_free_devt(dev_t devt); +extern dev_t blk_lookup_devt(const char *name, int partno); +extern char *disk_name (struct gendisk *hd, int partno, char *buf); + +extern int disk_expand_part_tbl(struct gendisk *disk, int target); +extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev); +extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev); +extern struct hd_struct * __must_check add_partition(struct gendisk *disk, + int partno, sector_t start, + sector_t len, int flags, + struct partition_meta_info + *info); +extern void __delete_partition(struct hd_struct *); +extern void delete_partition(struct gendisk *, int); +extern void printk_all_partitions(void); + +extern struct gendisk *alloc_disk_node(int minors, int node_id); +extern struct gendisk *alloc_disk(int minors); +extern struct kobject *get_disk(struct gendisk *disk); +extern void put_disk(struct gendisk *disk); +extern void blk_register_region(dev_t devt, unsigned long range, + struct module *module, + struct kobject *(*probe)(dev_t, int *, void *), + int (*lock)(dev_t, void *), + void *data); +extern void blk_unregister_region(dev_t devt, unsigned long range); + +extern ssize_t part_size_show(struct device *dev, + struct device_attribute *attr, char *buf); +extern ssize_t part_stat_show(struct device *dev, + struct device_attribute *attr, char *buf); +extern ssize_t part_inflight_show(struct device *dev, + struct device_attribute *attr, char *buf); +#ifdef CONFIG_FAIL_MAKE_REQUEST +extern ssize_t part_fail_show(struct device *dev, + struct device_attribute *attr, char *buf); +extern ssize_t part_fail_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count); +#endif /* CONFIG_FAIL_MAKE_REQUEST */ + +static inline void hd_ref_init(struct hd_struct *part) +{ + atomic_set(&part->ref, 1); + smp_mb(); +} + +static inline void hd_struct_get(struct hd_struct *part) +{ + atomic_inc(&part->ref); + smp_mb__after_atomic(); +} + +static inline int hd_struct_try_get(struct hd_struct *part) +{ + return atomic_inc_not_zero(&part->ref); +} + +static inline void hd_struct_put(struct hd_struct *part) +{ + if (atomic_dec_and_test(&part->ref)) + __delete_partition(part); +} + +/* + * Any access of part->nr_sects which is not protected by partition + * bd_mutex or gendisk bdev bd_mutex, should be done using this + * accessor function. + * + * Code written along the lines of i_size_read() and i_size_write(). + * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption + * on. + */ +static inline sector_t part_nr_sects_read(struct hd_struct *part) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + sector_t nr_sects; + unsigned seq; + do { + seq = read_seqcount_begin(&part->nr_sects_seq); + nr_sects = part->nr_sects; + } while (read_seqcount_retry(&part->nr_sects_seq, seq)); + return nr_sects; +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) + sector_t nr_sects; + + preempt_disable(); + nr_sects = part->nr_sects; + preempt_enable(); + return nr_sects; +#else + return part->nr_sects; +#endif +} + +/* + * Should be called with mutex lock held (typically bd_mutex) of partition + * to provide mutual exlusion among writers otherwise seqcount might be + * left in wrong state leaving the readers spinning infinitely. + */ +static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + write_seqcount_begin(&part->nr_sects_seq); + part->nr_sects = size; + write_seqcount_end(&part->nr_sects_seq); +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) + preempt_disable(); + part->nr_sects = size; + preempt_enable(); +#else + part->nr_sects = size; +#endif +} + +#else /* CONFIG_BLOCK */ + +static inline void printk_all_partitions(void) { } + +static inline dev_t blk_lookup_devt(const char *name, int partno) +{ + dev_t devt = MKDEV(0, 0); + return devt; +} + +static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to) +{ + return -EINVAL; +} +#endif /* CONFIG_BLOCK */ + +#endif /* _LINUX_GENHD_H */ |