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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 | /* * linux/fs/stat.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/errno.h> #include <linux/string.h> #include <linux/stat.h> #include <linux/fs.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <asm/segment.h> #ifndef __alpha__ /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ static void cp_old_stat(struct inode * inode, struct old_stat * statbuf) { struct old_stat tmp; printk("VFS: Warning: %s using old stat() call. Recompile your binary.\n", current->comm); tmp.st_dev = kdev_t_to_nr(inode->i_dev); tmp.st_ino = inode->i_ino; tmp.st_mode = inode->i_mode; tmp.st_nlink = inode->i_nlink; tmp.st_uid = inode->i_uid; tmp.st_gid = inode->i_gid; tmp.st_rdev = kdev_t_to_nr(inode->i_rdev); tmp.st_size = inode->i_size; if (inode->i_pipe) tmp.st_size = PIPE_SIZE(*inode); tmp.st_atime = inode->i_atime; tmp.st_mtime = inode->i_mtime; tmp.st_ctime = inode->i_ctime; memcpy_tofs(statbuf,&tmp,sizeof(tmp)); } #endif static void cp_new_stat(struct inode * inode, struct new_stat * statbuf) { struct new_stat tmp; unsigned int blocks, indirect; memset(&tmp, 0, sizeof(tmp)); tmp.st_dev = kdev_t_to_nr(inode->i_dev); tmp.st_ino = inode->i_ino; tmp.st_mode = inode->i_mode; tmp.st_nlink = inode->i_nlink; tmp.st_uid = inode->i_uid; tmp.st_gid = inode->i_gid; tmp.st_rdev = kdev_t_to_nr(inode->i_rdev); tmp.st_size = inode->i_size; if (inode->i_pipe) tmp.st_size = PIPE_SIZE(*inode); tmp.st_atime = inode->i_atime; tmp.st_mtime = inode->i_mtime; tmp.st_ctime = inode->i_ctime; /* * st_blocks and st_blksize are approximated with a simple algorithm if * they aren't supported directly by the filesystem. The minix and msdos * filesystems don't keep track of blocks, so they would either have to * be counted explicitly (by delving into the file itself), or by using * this simple algorithm to get a reasonable (although not 100% accurate) * value. */ /* * Use minix fs values for the number of direct and indirect blocks. The * count is now exact for the minix fs except that it counts zero blocks. * Everything is in BLOCK_SIZE'd units until the assignment to * tmp.st_blksize. */ #define D_B 7 #define I_B (BLOCK_SIZE / sizeof(unsigned short)) if (!inode->i_blksize) { blocks = (tmp.st_size + BLOCK_SIZE - 1) / BLOCK_SIZE; if (blocks > D_B) { indirect = (blocks - D_B + I_B - 1) / I_B; blocks += indirect; if (indirect > 1) { indirect = (indirect - 1 + I_B - 1) / I_B; blocks += indirect; if (indirect > 1) blocks++; } } tmp.st_blocks = (BLOCK_SIZE / 512) * blocks; tmp.st_blksize = BLOCK_SIZE; } else { tmp.st_blocks = inode->i_blocks; tmp.st_blksize = inode->i_blksize; } memcpy_tofs(statbuf,&tmp,sizeof(tmp)); } #ifndef __alpha__ /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ asmlinkage int sys_stat(char * filename, struct old_stat * statbuf) { struct inode * inode; int error; error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf)); if (error) return error; error = namei(filename,&inode); if (error) return error; cp_old_stat(inode,statbuf); iput(inode); return 0; } #endif asmlinkage int sys_newstat(char * filename, struct new_stat * statbuf) { struct inode * inode; int error; error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf)); if (error) return error; error = namei(filename,&inode); if (error) return error; cp_new_stat(inode,statbuf); iput(inode); return 0; } #ifndef __alpha__ /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ asmlinkage int sys_lstat(char * filename, struct old_stat * statbuf) { struct inode * inode; int error; error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf)); if (error) return error; error = lnamei(filename,&inode); if (error) return error; cp_old_stat(inode,statbuf); iput(inode); return 0; } #endif asmlinkage int sys_newlstat(char * filename, struct new_stat * statbuf) { struct inode * inode; int error; error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf)); if (error) return error; error = lnamei(filename,&inode); if (error) return error; cp_new_stat(inode,statbuf); iput(inode); return 0; } #ifndef __alpha__ /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ asmlinkage int sys_fstat(unsigned int fd, struct old_stat * statbuf) { struct file * f; struct inode * inode; int error; error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf)); if (error) return error; if (fd >= NR_OPEN || !(f=current->files->fd[fd]) || !(inode=f->f_inode)) return -EBADF; cp_old_stat(inode,statbuf); return 0; } #endif asmlinkage int sys_newfstat(unsigned int fd, struct new_stat * statbuf) { struct file * f; struct inode * inode; int error; error = verify_area(VERIFY_WRITE,statbuf,sizeof (*statbuf)); if (error) return error; if (fd >= NR_OPEN || !(f=current->files->fd[fd]) || !(inode=f->f_inode)) return -EBADF; cp_new_stat(inode,statbuf); return 0; } asmlinkage int sys_readlink(const char * path, char * buf, int bufsiz) { struct inode * inode; int error; if (bufsiz <= 0) return -EINVAL; error = verify_area(VERIFY_WRITE,buf,bufsiz); if (error) return error; error = lnamei(path,&inode); if (error) return error; if (!inode->i_op || !inode->i_op->readlink) { iput(inode); return -EINVAL; } return inode->i_op->readlink(inode,buf,bufsiz); } |