| 1 | #ifndef _BABELTRACE_COMPAT_FCNTL_H |
| 2 | #define _BABELTRACE_COMPAT_FCNTL_H |
| 3 | |
| 4 | /* |
| 5 | * babeltrace/compat/fcntl.h |
| 6 | * |
| 7 | * Copyright 2015 (c) - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 8 | * |
| 9 | * fcntl compatibility layer. |
| 10 | * |
| 11 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 12 | * of this software and associated documentation files (the "Software"), to deal |
| 13 | * in the Software without restriction, including without limitation the rights |
| 14 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 15 | * copies of the Software, and to permit persons to whom the Software is |
| 16 | * furnished to do so, subject to the following conditions: |
| 17 | * |
| 18 | * The above copyright notice and this permission notice shall be included in |
| 19 | * all copies or substantial portions of the Software. |
| 20 | * |
| 21 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 22 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 23 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 24 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 25 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 26 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 27 | * SOFTWARE. |
| 28 | */ |
| 29 | |
| 30 | #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE |
| 31 | |
| 32 | #include <fcntl.h> |
| 33 | |
| 34 | static inline |
| 35 | int bt_posix_fallocate(int fd, off_t offset, off_t len) |
| 36 | { |
| 37 | return posix_fallocate(fd, offset, len); |
| 38 | } |
| 39 | |
| 40 | #else /* #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */ |
| 41 | |
| 42 | #include <sys/types.h> |
| 43 | #include <unistd.h> |
| 44 | #include <string.h> |
| 45 | |
| 46 | #define BABELTRACE_FALLOCATE_BUFLEN 256 |
| 47 | |
| 48 | #ifndef min_t |
| 49 | #define min_t(type, a, b) \ |
| 50 | ((type) (a) < (type) (b) ? (type) (a) : (type) (b)) |
| 51 | #endif |
| 52 | |
| 53 | static inline |
| 54 | int bt_posix_fallocate(int fd, off_t offset, off_t len) |
| 55 | { |
| 56 | int ret = 0; |
| 57 | ssize_t copy_len; |
| 58 | char buf[BABELTRACE_FALLOCATE_BUFLEN]; |
| 59 | off_t i, file_pos, orig_end_offset, range_end; |
| 60 | |
| 61 | if (offset < 0 || len < 0) { |
| 62 | ret = EINVAL; |
| 63 | goto end; |
| 64 | } |
| 65 | |
| 66 | range_end = offset + len; |
| 67 | if (range_end < 0) { |
| 68 | ret = EFBIG; |
| 69 | goto end; |
| 70 | } |
| 71 | |
| 72 | file_pos = lseek(fd, 0, SEEK_CUR); |
| 73 | if (file_pos < 0) { |
| 74 | ret = errno; |
| 75 | goto end; |
| 76 | } |
| 77 | |
| 78 | orig_end_offset = lseek(fd, 0, SEEK_END); |
| 79 | if (orig_end_offset < 0) { |
| 80 | ret = errno; |
| 81 | goto end; |
| 82 | } |
| 83 | |
| 84 | /* Seek back to original position. */ |
| 85 | ret = lseek(fd, file_pos, SEEK_SET); |
| 86 | if (ret) { |
| 87 | ret = errno; |
| 88 | goto end; |
| 89 | } |
| 90 | |
| 91 | /* |
| 92 | * The file may not need to grow, but we want to ensure the |
| 93 | * space has actually been reserved by the file system. First, copy |
| 94 | * the "existing" region of the file, then grow the file if needed. |
| 95 | */ |
| 96 | for (i = file_pos; i < min_t(off_t, range_end, orig_end_offset); |
| 97 | i += copy_len) { |
| 98 | ssize_t copy_ret; |
| 99 | |
| 100 | copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN, |
| 101 | min_t(off_t, range_end - i, |
| 102 | orig_end_offset - i)); |
| 103 | copy_ret = pread(fd, &buf, copy_len, i); |
| 104 | if (copy_ret < copy_len) { |
| 105 | /* |
| 106 | * The caller must handle any EINTR. |
| 107 | * POSIX_FALLOCATE(3) does not mention EINTR. |
| 108 | * However, glibc does forward to fallocate() |
| 109 | * directly on Linux, which may be interrupted. |
| 110 | */ |
| 111 | ret = errno; |
| 112 | goto end; |
| 113 | } |
| 114 | |
| 115 | copy_ret = pwrite(fd, &buf, copy_len, i); |
| 116 | if (copy_ret < copy_len) { |
| 117 | /* Same caveat as noted at pread() */ |
| 118 | ret = errno; |
| 119 | goto end; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | /* Grow file, as necessary. */ |
| 124 | memset(&buf, 0, BABELTRACE_FALLOCATE_BUFLEN); |
| 125 | for (i = orig_end_offset; i < range_end; i += copy_len) { |
| 126 | ssize_t write_ret; |
| 127 | |
| 128 | copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN, |
| 129 | range_end - i); |
| 130 | write_ret = pwrite(fd, &buf, copy_len, i); |
| 131 | if (write_ret < copy_len) { |
| 132 | ret = errno; |
| 133 | goto end; |
| 134 | } |
| 135 | } |
| 136 | end: |
| 137 | return ret; |
| 138 | } |
| 139 | #endif /* #else #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */ |
| 140 | |
| 141 | |
| 142 | #ifdef BABELTRACE_HAVE_FACCESSAT |
| 143 | |
| 144 | #include <fcntl.h> |
| 145 | #include <unistd.h> |
| 146 | |
| 147 | static inline |
| 148 | int bt_faccessat(int dirfd, const char *dirname, |
| 149 | const char *pathname, int mode, int flags) |
| 150 | { |
| 151 | return faccessat(dirfd, pathname, mode, flags); |
| 152 | } |
| 153 | |
| 154 | #else /* #ifdef BABELTRACE_HAVE_FACCESSAT */ |
| 155 | |
| 156 | #include <string.h> |
| 157 | #include <unistd.h> |
| 158 | |
| 159 | static inline |
| 160 | int bt_faccessat(int dirfd, const char *dirname, |
| 161 | const char *pathname, int mode, int flags) |
| 162 | { |
| 163 | char cpath[PATH_MAX]; |
| 164 | |
| 165 | if (flags != 0) { |
| 166 | errno = EINVAL; |
| 167 | return -1; |
| 168 | } |
| 169 | /* Includes middle / and final \0. */ |
| 170 | if (strlen(dirname) + strlen(pathname) + 2 > PATH_MAX) { |
| 171 | return -1; |
| 172 | } |
| 173 | strcpy(cpath, dirname); |
| 174 | strcat(cpath, "/"); |
| 175 | strcat(cpath, pathname); |
| 176 | return access(cpath, mode); |
| 177 | } |
| 178 | |
| 179 | #endif /* #else #ifdef BABELTRACE_HAVE_FACCESSAT */ |
| 180 | |
| 181 | #endif /* _BABELTRACE_COMPAT_FCNTL_H */ |