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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 | /* * linux/fs/stat.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/errno.h> #include <linux/stat.h> #include <linux/fs.h> #include <linux/sched.h> #include <linux/kernel.h> #include <asm/segment.h> static void cp_old_stat(struct inode * inode, struct old_stat * statbuf) { struct old_stat tmp; printk("Warning: %s using old stat() call. Recompile your binary.\n", current->comm); verify_area(statbuf,sizeof (*statbuf)); tmp.st_dev = 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 = inode->i_rdev; tmp.st_size = inode->i_size; tmp.st_atime = inode->i_atime; tmp.st_mtime = inode->i_mtime; tmp.st_ctime = inode->i_ctime; memcpy_tofs(statbuf,&tmp,sizeof(tmp)); } static void cp_new_stat(struct inode * inode, struct new_stat * statbuf) { struct new_stat tmp = {0, }; unsigned int blocks, indirect; verify_area(statbuf,sizeof (*statbuf)); tmp.st_dev = 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 = inode->i_rdev; tmp.st_size = inode->i_size; 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. */ if (!inode->i_blksize) { blocks = (tmp.st_size + 511) / 512; if (blocks > 10) { indirect = (blocks - 11)/256+1; if (blocks > 10+256) { indirect += (blocks - 267)/(256*256)+1; if (blocks > 10+256+256*256) indirect++; } blocks += indirect; } tmp.st_blocks = 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)); } int sys_stat(char * filename, struct old_stat * statbuf) { struct inode * inode; int error; error = namei(filename,&inode); if (error) return error; cp_old_stat(inode,statbuf); iput(inode); return 0; } int sys_newstat(char * filename, struct new_stat * statbuf) { struct inode * inode; int error; error = namei(filename,&inode); if (error) return error; cp_new_stat(inode,statbuf); iput(inode); return 0; } int sys_lstat(char * filename, struct old_stat * statbuf) { struct inode * inode; int error; error = lnamei(filename,&inode); if (error) return error; cp_old_stat(inode,statbuf); iput(inode); return 0; } int sys_newlstat(char * filename, struct new_stat * statbuf) { struct inode * inode; int error; error = lnamei(filename,&inode); if (error) return error; cp_new_stat(inode,statbuf); iput(inode); return 0; } int sys_fstat(unsigned int fd, struct old_stat * statbuf) { struct file * f; struct inode * inode; if (fd >= NR_OPEN || !(f=current->filp[fd]) || !(inode=f->f_inode)) return -EBADF; cp_old_stat(inode,statbuf); return 0; } int sys_newfstat(unsigned int fd, struct new_stat * statbuf) { struct file * f; struct inode * inode; if (fd >= NR_OPEN || !(f=current->filp[fd]) || !(inode=f->f_inode)) return -EBADF; cp_new_stat(inode,statbuf); return 0; } int sys_readlink(const char * path, char * buf, int bufsiz) { struct inode * inode; int error; if (bufsiz <= 0) return -EINVAL; verify_area(buf,bufsiz); 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); } |