/* * linux/fs/stat.c * * (C) 1991 Linus Torvalds */ #include <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; if (inode->i_ino & 0xffff0000) printk("Warning: using old stat() call on bigfs\n"); 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; if( S_ISFIFO(inode->i_mode) ) tmp.st_size = 0; else 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; if( S_ISFIFO(inode->i_mode) ) tmp.st_size = 0; else tmp.st_size = inode->i_size; tmp.st_atime = inode->i_atime; tmp.st_mtime = inode->i_mtime; tmp.st_ctime = inode->i_ctime; /* * Right now we fake the st_blocks numbers: we'll eventually have to * add st_blocks to the inode, and let the vfs routines keep track of * it all. This algorithm doesn't guarantee correct block numbers, but * at least it tries to come up with a plausible answer... * * In fact, the minix fs doesn't use these numbers (it uses 7 and 512 * instead of 10 and 256), but who cares... It's not that exact anyway. */ blocks = (tmp.st_size + 1023) / 1024; 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_blksize = 1024; tmp.st_blocks = blocks; memcpy_tofs(statbuf,&tmp,sizeof(tmp)); } int sys_stat(char * filename, struct old_stat * statbuf) { struct inode * inode; if (!(inode=namei(filename))) return -ENOENT; cp_old_stat(inode,statbuf); iput(inode); return 0; } int sys_newstat(char * filename, struct new_stat * statbuf) { struct inode * inode; if (!(inode=namei(filename))) return -ENOENT; cp_new_stat(inode,statbuf); iput(inode); return 0; } int sys_lstat(char * filename, struct old_stat * statbuf) { struct inode * inode; if (!(inode = lnamei(filename))) return -ENOENT; cp_old_stat(inode,statbuf); iput(inode); return 0; } int sys_newlstat(char * filename, struct new_stat * statbuf) { struct inode * inode; if (!(inode = lnamei(filename))) return -ENOENT; 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; if (bufsiz <= 0) return -EINVAL; verify_area(buf,bufsiz); if (!(inode = lnamei(path))) return -ENOENT; if (!inode->i_op || !inode->i_op->readlink) { iput(inode); return -EINVAL; } return inode->i_op->readlink(inode,buf,bufsiz); }