| 1 | #ifndef _BABELTRACE_COMPAT_FCNTL_H |
| 2 | #define _BABELTRACE_COMPAT_FCNTL_H |
| 3 | |
| 4 | /* |
| 5 | * Copyright 2015 (c) - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 6 | * |
| 7 | * fcntl compatibility layer. |
| 8 | * |
| 9 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 10 | * of this software and associated documentation files (the "Software"), to deal |
| 11 | * in the Software without restriction, including without limitation the rights |
| 12 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 13 | * copies of the Software, and to permit persons to whom the Software is |
| 14 | * furnished to do so, subject to the following conditions: |
| 15 | * |
| 16 | * The above copyright notice and this permission notice shall be included in |
| 17 | * all copies or substantial portions of the Software. |
| 18 | * |
| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 20 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 22 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 23 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 24 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 25 | * SOFTWARE. |
| 26 | */ |
| 27 | |
| 28 | #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE |
| 29 | |
| 30 | #include <fcntl.h> |
| 31 | |
| 32 | static inline |
| 33 | int bt_posix_fallocate(int fd, off_t offset, off_t len) |
| 34 | { |
| 35 | return posix_fallocate(fd, offset, len); |
| 36 | } |
| 37 | |
| 38 | #elif defined(__MINGW32__) /* #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */ |
| 39 | |
| 40 | #include <stdlib.h> |
| 41 | #include <windows.h> |
| 42 | #include <fcntl.h> |
| 43 | |
| 44 | static inline |
| 45 | int bt_posix_fallocate(int fd, off_t offset, off_t len) |
| 46 | { |
| 47 | HANDLE handle; |
| 48 | LARGE_INTEGER pos, file_pos, orig_end_offset, range_end; |
| 49 | int ret = 0; |
| 50 | char zero = 0; |
| 51 | DWORD byteswritten; |
| 52 | |
| 53 | if (offset < 0 || len <= 0) { |
| 54 | ret = EINVAL; |
| 55 | goto end; |
| 56 | } |
| 57 | |
| 58 | range_end.QuadPart = (__int64) offset + (__int64) len; |
| 59 | |
| 60 | /* Get a handle from the fd */ |
| 61 | handle = (HANDLE) _get_osfhandle(fd); |
| 62 | if (handle == INVALID_HANDLE_VALUE) { |
| 63 | ret = EBADF; |
| 64 | goto end; |
| 65 | } |
| 66 | |
| 67 | /* Get the file original end offset */ |
| 68 | ret = GetFileSizeEx(handle, &orig_end_offset); |
| 69 | if (ret == 0) { |
| 70 | ret = EBADF; |
| 71 | goto end; |
| 72 | } |
| 73 | |
| 74 | /* Make sure we don't truncate the file */ |
| 75 | if (orig_end_offset.QuadPart >= range_end.QuadPart) { |
| 76 | ret = 0; |
| 77 | goto end; |
| 78 | } |
| 79 | |
| 80 | /* Get the current file pointer position */ |
| 81 | pos.QuadPart = 0; |
| 82 | ret = SetFilePointerEx(handle, pos, &file_pos, FILE_CURRENT); |
| 83 | if (ret == 0) { |
| 84 | ret = EBADF; |
| 85 | goto end; |
| 86 | } |
| 87 | |
| 88 | /* Move the file pointer to the new end offset */ |
| 89 | ret = SetFilePointerEx(handle, range_end, NULL, FILE_BEGIN); |
| 90 | if (ret == 0) { |
| 91 | ret = EBADF; |
| 92 | goto end; |
| 93 | } |
| 94 | |
| 95 | /* Sets the physical file size to the current position */ |
| 96 | ret = SetEndOfFile(handle); |
| 97 | if (ret == 0) { |
| 98 | ret = EINVAL; |
| 99 | goto restore; |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * Move the file pointer back 1 byte, and write a single 0 at the |
| 104 | * last byte of the new end offset, the operating system will zero |
| 105 | * fill the file. |
| 106 | */ |
| 107 | pos.QuadPart = -1; |
| 108 | ret = SetFilePointerEx(handle, pos, NULL, FILE_END); |
| 109 | if (ret == 0) { |
| 110 | ret = EBADF; |
| 111 | goto end; |
| 112 | } |
| 113 | |
| 114 | ret = WriteFile(handle, &zero, 1, &byteswritten, NULL); |
| 115 | if (ret == 0 || byteswritten != 1) { |
| 116 | ret = ENOSPC; |
| 117 | } else { |
| 118 | ret = 0; |
| 119 | } |
| 120 | |
| 121 | restore: |
| 122 | /* Restore the original file pointer position */ |
| 123 | if (!SetFilePointerEx(handle, file_pos, NULL, FILE_BEGIN)) { |
| 124 | /* We moved the file pointer but failed to restore it. */ |
| 125 | abort(); |
| 126 | } |
| 127 | |
| 128 | end: |
| 129 | return ret; |
| 130 | } |
| 131 | |
| 132 | #else |
| 133 | |
| 134 | #include <sys/types.h> |
| 135 | #include <unistd.h> |
| 136 | #include <string.h> |
| 137 | |
| 138 | #define BABELTRACE_FALLOCATE_BUFLEN 256 |
| 139 | |
| 140 | #ifndef min_t |
| 141 | #define min_t(type, a, b) \ |
| 142 | ((type) (a) < (type) (b) ? (type) (a) : (type) (b)) |
| 143 | #endif |
| 144 | |
| 145 | static inline |
| 146 | int bt_posix_fallocate(int fd, off_t offset, off_t len) |
| 147 | { |
| 148 | int ret = 0; |
| 149 | ssize_t copy_len; |
| 150 | char buf[BABELTRACE_FALLOCATE_BUFLEN]; |
| 151 | off_t i, file_pos, orig_end_offset, range_end; |
| 152 | |
| 153 | if (offset < 0 || len < 0) { |
| 154 | ret = EINVAL; |
| 155 | goto end; |
| 156 | } |
| 157 | |
| 158 | range_end = offset + len; |
| 159 | if (range_end < 0) { |
| 160 | ret = EFBIG; |
| 161 | goto end; |
| 162 | } |
| 163 | |
| 164 | file_pos = lseek(fd, 0, SEEK_CUR); |
| 165 | if (file_pos < 0) { |
| 166 | ret = errno; |
| 167 | goto end; |
| 168 | } |
| 169 | |
| 170 | orig_end_offset = lseek(fd, 0, SEEK_END); |
| 171 | if (orig_end_offset < 0) { |
| 172 | ret = errno; |
| 173 | goto end; |
| 174 | } |
| 175 | |
| 176 | /* Seek back to original position. */ |
| 177 | ret = lseek(fd, file_pos, SEEK_SET); |
| 178 | if (ret) { |
| 179 | ret = errno; |
| 180 | goto end; |
| 181 | } |
| 182 | |
| 183 | /* |
| 184 | * The file may not need to grow, but we want to ensure the |
| 185 | * space has actually been reserved by the file system. First, copy |
| 186 | * the "existing" region of the file, then grow the file if needed. |
| 187 | */ |
| 188 | for (i = file_pos; i < min_t(off_t, range_end, orig_end_offset); |
| 189 | i += copy_len) { |
| 190 | ssize_t copy_ret; |
| 191 | |
| 192 | copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN, |
| 193 | min_t(off_t, range_end - i, |
| 194 | orig_end_offset - i)); |
| 195 | copy_ret = pread(fd, &buf, copy_len, i); |
| 196 | if (copy_ret < copy_len) { |
| 197 | /* |
| 198 | * The caller must handle any EINTR. |
| 199 | * POSIX_FALLOCATE(3) does not mention EINTR. |
| 200 | * However, glibc does forward to fallocate() |
| 201 | * directly on Linux, which may be interrupted. |
| 202 | */ |
| 203 | ret = errno; |
| 204 | goto end; |
| 205 | } |
| 206 | |
| 207 | copy_ret = pwrite(fd, &buf, copy_len, i); |
| 208 | if (copy_ret < copy_len) { |
| 209 | /* Same caveat as noted at pread() */ |
| 210 | ret = errno; |
| 211 | goto end; |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | /* Grow file, as necessary. */ |
| 216 | memset(&buf, 0, BABELTRACE_FALLOCATE_BUFLEN); |
| 217 | for (i = orig_end_offset; i < range_end; i += copy_len) { |
| 218 | ssize_t write_ret; |
| 219 | |
| 220 | copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN, |
| 221 | range_end - i); |
| 222 | write_ret = pwrite(fd, &buf, copy_len, i); |
| 223 | if (write_ret < copy_len) { |
| 224 | ret = errno; |
| 225 | goto end; |
| 226 | } |
| 227 | } |
| 228 | end: |
| 229 | return ret; |
| 230 | } |
| 231 | #endif /* #else #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */ |
| 232 | |
| 233 | #endif /* _BABELTRACE_COMPAT_FCNTL_H */ |