mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 22:26:12 +00:00
2363cc0264
Revert all this. It can cause device-mapper to receive a different major from earlier kernels and it turns out that the Amanda backup program (via GNU tar, apparently) checks major numbers on files when performing incremental backups. Which is a bit broken of Amanda (or tar), but this feature isn't important enough to justify the churn. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
101 lines
2.0 KiB
C
101 lines
2.0 KiB
C
#ifndef _LINUX_KDEV_T_H
|
|
#define _LINUX_KDEV_T_H
|
|
#ifdef __KERNEL__
|
|
#define MINORBITS 20
|
|
#define MINORMASK ((1U << MINORBITS) - 1)
|
|
|
|
#define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS))
|
|
#define MINOR(dev) ((unsigned int) ((dev) & MINORMASK))
|
|
#define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi))
|
|
|
|
#define print_dev_t(buffer, dev) \
|
|
sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev))
|
|
|
|
#define format_dev_t(buffer, dev) \
|
|
({ \
|
|
sprintf(buffer, "%u:%u", MAJOR(dev), MINOR(dev)); \
|
|
buffer; \
|
|
})
|
|
|
|
/* acceptable for old filesystems */
|
|
static inline int old_valid_dev(dev_t dev)
|
|
{
|
|
return MAJOR(dev) < 256 && MINOR(dev) < 256;
|
|
}
|
|
|
|
static inline u16 old_encode_dev(dev_t dev)
|
|
{
|
|
return (MAJOR(dev) << 8) | MINOR(dev);
|
|
}
|
|
|
|
static inline dev_t old_decode_dev(u16 val)
|
|
{
|
|
return MKDEV((val >> 8) & 255, val & 255);
|
|
}
|
|
|
|
static inline int new_valid_dev(dev_t dev)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline u32 new_encode_dev(dev_t dev)
|
|
{
|
|
unsigned major = MAJOR(dev);
|
|
unsigned minor = MINOR(dev);
|
|
return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);
|
|
}
|
|
|
|
static inline dev_t new_decode_dev(u32 dev)
|
|
{
|
|
unsigned major = (dev & 0xfff00) >> 8;
|
|
unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
|
|
return MKDEV(major, minor);
|
|
}
|
|
|
|
static inline int huge_valid_dev(dev_t dev)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline u64 huge_encode_dev(dev_t dev)
|
|
{
|
|
return new_encode_dev(dev);
|
|
}
|
|
|
|
static inline dev_t huge_decode_dev(u64 dev)
|
|
{
|
|
return new_decode_dev(dev);
|
|
}
|
|
|
|
static inline int sysv_valid_dev(dev_t dev)
|
|
{
|
|
return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18);
|
|
}
|
|
|
|
static inline u32 sysv_encode_dev(dev_t dev)
|
|
{
|
|
return MINOR(dev) | (MAJOR(dev) << 18);
|
|
}
|
|
|
|
static inline unsigned sysv_major(u32 dev)
|
|
{
|
|
return (dev >> 18) & 0x3fff;
|
|
}
|
|
|
|
static inline unsigned sysv_minor(u32 dev)
|
|
{
|
|
return dev & 0x3ffff;
|
|
}
|
|
|
|
#else /* __KERNEL__ */
|
|
|
|
/*
|
|
Some programs want their definitions of MAJOR and MINOR and MKDEV
|
|
from the kernel sources. These must be the externally visible ones.
|
|
*/
|
|
#define MAJOR(dev) ((dev)>>8)
|
|
#define MINOR(dev) ((dev) & 0xff)
|
|
#define MKDEV(ma,mi) ((ma)<<8 | (mi))
|
|
#endif /* __KERNEL__ */
|
|
#endif
|