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