1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <unistd.h> 30 31 #include <errno.h> 32 #include <limits.h> 33 #include <sys/vfs.h> 34 35 static long __filesizebits(const struct statfs& s) { 36 switch (s.f_type) { 37 case JFFS2_SUPER_MAGIC: 38 case MSDOS_SUPER_MAGIC: 39 case NCP_SUPER_MAGIC: 40 return 32; 41 } 42 // There won't be any new 32-bit file systems. 43 return 64; 44 } 45 46 static long __link_max(const struct statfs& s) { 47 // These constant values were taken from kernel headers. 48 // They're not available in uapi headers. 49 switch (s.f_type) { 50 case EXT2_SUPER_MAGIC: 51 return 32000; 52 case MINIX_SUPER_MAGIC: 53 return 250; 54 case MINIX2_SUPER_MAGIC: 55 return 65530; 56 case REISERFS_SUPER_MAGIC: 57 return 0xffff - 1000; 58 case UFS_MAGIC: 59 return 32000; 60 } 61 return LINK_MAX; 62 } 63 64 static long __2_symlinks(const struct statfs& s) { 65 switch (s.f_type) { 66 case ADFS_SUPER_MAGIC: 67 case BFS_MAGIC: 68 case CRAMFS_MAGIC: 69 case EFS_SUPER_MAGIC: 70 case MSDOS_SUPER_MAGIC: 71 case QNX4_SUPER_MAGIC: 72 return 0; 73 } 74 return 1; 75 } 76 77 static long __pathconf(const struct statfs& s, int name) { 78 switch (name) { 79 case _PC_FILESIZEBITS: 80 return __filesizebits(s); 81 82 case _PC_LINK_MAX: 83 return __link_max(s); 84 85 case _PC_MAX_CANON: 86 return MAX_CANON; 87 88 case _PC_MAX_INPUT: 89 return MAX_INPUT; 90 91 case _PC_NAME_MAX: 92 return s.f_namelen; 93 94 case _PC_PATH_MAX: 95 return PATH_MAX; 96 97 case _PC_PIPE_BUF: 98 return PIPE_BUF; 99 100 case _PC_2_SYMLINKS: 101 return __2_symlinks(s); 102 103 case _PC_ALLOC_SIZE_MIN: /* fall through */ 104 case _PC_REC_XFER_ALIGN: 105 return s.f_frsize; 106 107 case _PC_REC_MIN_XFER_SIZE: 108 return s.f_bsize; 109 110 #if 0 111 case _PC_REC_INCR_XFER_SIZE: 112 case _PC_REC_MAX_XFER_SIZE: 113 #endif 114 115 case _PC_SYMLINK_MAX: 116 return -1; /* no limit */ 117 118 case _PC_CHOWN_RESTRICTED: 119 return _POSIX_CHOWN_RESTRICTED; 120 121 case _PC_NO_TRUNC: 122 return _POSIX_NO_TRUNC; 123 124 case _PC_VDISABLE: 125 return _POSIX_VDISABLE; 126 127 case _PC_ASYNC_IO: 128 return -1; 129 130 case _PC_PRIO_IO: 131 return -1; 132 133 case _PC_SYNC_IO: 134 return -1; 135 136 default: 137 errno = EINVAL; 138 return -1; 139 } 140 } 141 142 long pathconf(const char* path, int name) { 143 struct statfs sb; 144 if (statfs(path, &sb) == -1) { 145 return -1; 146 } 147 return __pathconf(sb, name); 148 } 149 150 long fpathconf(int fd, int name) { 151 struct statfs sb; 152 if (fstatfs(fd, &sb) == -1) { 153 return -1; 154 } 155 return __pathconf(sb, name); 156 } 157
