| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | #ifndef _LINUX_FS_TYPES_H |
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| 3 | #define _LINUX_FS_TYPES_H |
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| 4 | |
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| 5 | /* |
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| 6 | * This is a header for the common implementation of dirent |
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| 7 | * to fs on-disk file type conversion. Although the fs on-disk |
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| 8 | * bits are specific to every file system, in practice, many |
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| 9 | * file systems use the exact same on-disk format to describe |
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| 10 | * the lower 3 file type bits that represent the 7 POSIX file |
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| 11 | * types. |
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| 12 | * |
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| 13 | * It is important to note that the definitions in this |
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| 14 | * header MUST NOT change. This would break both the |
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| 15 | * userspace ABI and the on-disk format of filesystems |
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| 16 | * using this code. |
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| 17 | * |
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| 18 | * All those file systems can use this generic code for the |
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| 19 | * conversions. |
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| 20 | */ |
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| 21 | |
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| 22 | /* |
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| 23 | * struct dirent file types |
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| 24 | * exposed to user via getdents(2), readdir(3) |
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| 25 | * |
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| 26 | * These match bits 12..15 of stat.st_mode |
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| 27 | * (ie "(i_mode >> 12) & 15"). |
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| 28 | */ |
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| 29 | #define S_DT_SHIFT 12 |
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| 30 | #define S_DT(mode) (((mode) & S_IFMT) >> S_DT_SHIFT) |
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| 31 | #define S_DT_MASK (S_IFMT >> S_DT_SHIFT) |
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| 32 | |
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| 33 | /* these are defined by POSIX and also present in glibc's dirent.h */ |
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| 34 | #define DT_UNKNOWN 0 |
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| 35 | #define DT_FIFO 1 |
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| 36 | #define DT_CHR 2 |
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| 37 | #define DT_DIR 4 |
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| 38 | #define DT_BLK 6 |
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| 39 | #define DT_REG 8 |
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| 40 | #define DT_LNK 10 |
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| 41 | #define DT_SOCK 12 |
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| 42 | #define DT_WHT 14 |
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| 43 | |
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| 44 | #define DT_MAX (S_DT_MASK + 1) /* 16 */ |
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| 45 | |
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| 46 | /* |
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| 47 | * fs on-disk file types. |
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| 48 | * Only the low 3 bits are used for the POSIX file types. |
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| 49 | * Other bits are reserved for fs private use. |
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| 50 | * These definitions are shared and used by multiple filesystems, |
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| 51 | * and MUST NOT change under any circumstances. |
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| 52 | * |
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| 53 | * Note that no fs currently stores the whiteout type on-disk, |
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| 54 | * so whiteout dirents are exposed to user as DT_CHR. |
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| 55 | */ |
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| 56 | #define FT_UNKNOWN 0 |
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| 57 | #define FT_REG_FILE 1 |
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| 58 | #define FT_DIR 2 |
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| 59 | #define FT_CHRDEV 3 |
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| 60 | #define FT_BLKDEV 4 |
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| 61 | #define FT_FIFO 5 |
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| 62 | #define FT_SOCK 6 |
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| 63 | #define FT_SYMLINK 7 |
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| 64 | |
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| 65 | #define FT_MAX 8 |
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| 66 | |
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| 67 | /* |
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| 68 | * declarations for helper functions, accompanying implementation |
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| 69 | * is in fs/fs_types.c |
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| 70 | */ |
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| 71 | extern unsigned char fs_ftype_to_dtype(unsigned int filetype); |
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| 72 | extern unsigned char fs_umode_to_ftype(umode_t mode); |
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| 73 | extern unsigned char fs_umode_to_dtype(umode_t mode); |
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| 74 | |
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| 75 | #endif |
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| 76 | |
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