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
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#define _LINUX_KDEV_T_H
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#ifdef __KERNEL__
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#define MINORBITS 20
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#define MINORMASK ((1U << MINORBITS) - 1)
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#define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS))
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#define MINOR(dev) ((unsigned int) ((dev) & MINORMASK))
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#define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi))
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#define print_dev_t(buffer, dev) \
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sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev))
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#define format_dev_t(buffer, dev) \
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({ \
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sprintf(buffer, "%u:%u", MAJOR(dev), MINOR(dev)); \
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buffer; \
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})
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/* acceptable for old filesystems */
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static inline int old_valid_dev(dev_t dev)
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{
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return MAJOR(dev) < 256 && MINOR(dev) < 256;
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}
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static inline u16 old_encode_dev(dev_t dev)
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{
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return (MAJOR(dev) << 8) | MINOR(dev);
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}
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static inline dev_t old_decode_dev(u16 val)
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{
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return MKDEV((val >> 8) & 255, val & 255);
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}
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static inline int new_valid_dev(dev_t dev)
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{
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return 1;
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}
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static inline u32 new_encode_dev(dev_t dev)
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{
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unsigned major = MAJOR(dev);
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unsigned minor = MINOR(dev);
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return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);
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}
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static inline dev_t new_decode_dev(u32 dev)
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{
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unsigned major = (dev & 0xfff00) >> 8;
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unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
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return MKDEV(major, minor);
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}
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static inline int huge_valid_dev(dev_t dev)
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{
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return 1;
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}
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static inline u64 huge_encode_dev(dev_t dev)
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{
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return new_encode_dev(dev);
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}
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static inline dev_t huge_decode_dev(u64 dev)
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{
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return new_decode_dev(dev);
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}
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static inline int sysv_valid_dev(dev_t dev)
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{
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return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18);
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}
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static inline u32 sysv_encode_dev(dev_t dev)
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{
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return MINOR(dev) | (MAJOR(dev) << 18);
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}
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static inline unsigned sysv_major(u32 dev)
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{
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return (dev >> 18) & 0x3fff;
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}
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static inline unsigned sysv_minor(u32 dev)
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{
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return dev & 0x3ffff;
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}
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#else /* __KERNEL__ */
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/*
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Some programs want their definitions of MAJOR and MINOR and MKDEV
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from the kernel sources. These must be the externally visible ones.
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*/
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#define MAJOR(dev) ((dev)>>8)
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#define MINOR(dev) ((dev) & 0xff)
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#define MKDEV(ma,mi) ((ma)<<8 | (mi))
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#endif /* __KERNEL__ */
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#endif
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