/* *  linux/fs/stat.c * *  Copyright (C) 1991, 1992  Linus Torvalds */ #include <linux/config.h>#include <linux/module.h>#include <linux/mm.h>#include <linux/errno.h>#include <linux/file.h>#include <linux/smp_lock.h>#include <linux/highuid.h>#include <linux/fs.h>#include <linux/namei.h>#include <linux/security.h>#include <linux/syscalls.h> #include <asm/uaccess.h>#include <asm/unistd.h> void generic_fillattr(struct inode *inode, struct kstat *stat){	stat->dev = inode->i_sb->s_dev;	stat->ino = inode->i_ino;	stat->mode = inode->i_mode;	stat->nlink = inode->i_nlink;	stat->uid = inode->i_uid;	stat->gid = inode->i_gid;	stat->rdev = inode->i_rdev;	stat->atime = inode->i_atime;	stat->mtime = inode->i_mtime;	stat->ctime = inode->i_ctime;	stat->size = i_size_read(inode);	stat->blocks = inode->i_blocks;	stat->blksize = inode->i_blksize;} EXPORT_SYMBOL(generic_fillattr); int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat){	struct inode *inode = dentry->d_inode;	int retval; 	retval = security_inode_getattr(mnt, dentry);	if (retval)		return retval; 	if (inode->i_op->getattr)		return inode->i_op->getattr(mnt, dentry, stat); 	generic_fillattr(inode, stat);	if (!stat->blksize) {		struct super_block *s = inode->i_sb;		unsigned blocks;		blocks = (stat->size+s->s_blocksize-1) >> s->s_blocksize_bits;		stat->blocks = (s->s_blocksize / 512) * blocks;		stat->blksize = s->s_blocksize;	}	return 0;} EXPORT_SYMBOL(vfs_getattr); int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat){	struct nameidata nd;	int error; 	error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd);	if (!error) {		error = vfs_getattr(nd.mnt, nd.dentry, stat);		path_release(&nd);	}	return error;} int vfs_stat(char __user *name, struct kstat *stat){	return vfs_stat_fd(AT_FDCWD, name, stat);} EXPORT_SYMBOL(vfs_stat); int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat){	struct nameidata nd;	int error; 	error = __user_walk_fd(dfd, name, 0, &nd);	if (!error) {		error = vfs_getattr(nd.mnt, nd.dentry, stat);		path_release(&nd);	}	return error;} int vfs_lstat(char __user *name, struct kstat *stat){	return vfs_lstat_fd(AT_FDCWD, name, stat);} EXPORT_SYMBOL(vfs_lstat); int vfs_fstat(unsigned int fd, struct kstat *stat){	struct file *f = fget(fd);	int error = -EBADF; 	if (f) {		error = vfs_getattr(f->f_vfsmnt, f->f_dentry, stat);		fput(f);	}	return error;} EXPORT_SYMBOL(vfs_fstat); #ifdef __ARCH_WANT_OLD_STAT /* * For backward compatibility?  Maybe this should be moved * into arch/i386 instead? */static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf){	static int warncount = 5;	struct __old_kernel_stat tmp;		if (warncount > 0) {		warncount--;		printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",			current->comm);	} else if (warncount < 0) {		/* it's laughable, but... */		warncount = 0;	} 	memset(&tmp, 0, sizeof(struct __old_kernel_stat));	tmp.st_dev = old_encode_dev(stat->dev);	tmp.st_ino = stat->ino;	tmp.st_mode = stat->mode;	tmp.st_nlink = stat->nlink;	if (tmp.st_nlink != stat->nlink)		return -EOVERFLOW;	SET_UID(tmp.st_uid, stat->uid);	SET_GID(tmp.st_gid, stat->gid);	tmp.st_rdev = old_encode_dev(stat->rdev);#if BITS_PER_LONG == 32	if (stat->size > MAX_NON_LFS)		return -EOVERFLOW;#endif		tmp.st_size = stat->size;	tmp.st_atime = stat->atime.tv_sec;	tmp.st_mtime = stat->mtime.tv_sec;	tmp.st_ctime = stat->ctime.tv_sec;	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;} asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf){	struct kstat stat;	int error = vfs_stat_fd(AT_FDCWD, filename, &stat); 	if (!error)		error = cp_old_stat(&stat, statbuf); 	return error;}asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf){	struct kstat stat;	int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); 	if (!error)		error = cp_old_stat(&stat, statbuf); 	return error;}asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf){	struct kstat stat;	int error = vfs_fstat(fd, &stat); 	if (!error)		error = cp_old_stat(&stat, statbuf); 	return error;} #endif /* __ARCH_WANT_OLD_STAT */ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf){	struct stat tmp; #if BITS_PER_LONG == 32	if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))		return -EOVERFLOW;#else	if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))		return -EOVERFLOW;#endif 	memset(&tmp, 0, sizeof(tmp));#if BITS_PER_LONG == 32	tmp.st_dev = old_encode_dev(stat->dev);#else	tmp.st_dev = new_encode_dev(stat->dev);#endif	tmp.st_ino = stat->ino;	tmp.st_mode = stat->mode;	tmp.st_nlink = stat->nlink;	if (tmp.st_nlink != stat->nlink)		return -EOVERFLOW;	SET_UID(tmp.st_uid, stat->uid);	SET_GID(tmp.st_gid, stat->gid);#if BITS_PER_LONG == 32	tmp.st_rdev = old_encode_dev(stat->rdev);#else	tmp.st_rdev = new_encode_dev(stat->rdev);#endif#if BITS_PER_LONG == 32	if (stat->size > MAX_NON_LFS)		return -EOVERFLOW;#endif		tmp.st_size = stat->size;	tmp.st_atime = stat->atime.tv_sec;	tmp.st_mtime = stat->mtime.tv_sec;	tmp.st_ctime = stat->ctime.tv_sec;#ifdef STAT_HAVE_NSEC	tmp.st_atime_nsec = stat->atime.tv_nsec;	tmp.st_mtime_nsec = stat->mtime.tv_nsec;	tmp.st_ctime_nsec = stat->ctime.tv_nsec;#endif	tmp.st_blocks = stat->blocks;	tmp.st_blksize = stat->blksize;	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;} asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf){	struct kstat stat;	int error = vfs_stat_fd(AT_FDCWD, filename, &stat); 	if (!error)		error = cp_new_stat(&stat, statbuf); 	return error;} asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf){	struct kstat stat;	int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); 	if (!error)		error = cp_new_stat(&stat, statbuf); 	return error;} #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)asmlinkage long sys_newfstatat(int dfd, char __user *filename,				struct stat __user *statbuf, int flag){	struct kstat stat;	int error = -EINVAL; 	if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)		goto out; 	if (flag & AT_SYMLINK_NOFOLLOW)		error = vfs_lstat_fd(dfd, filename, &stat);	else		error = vfs_stat_fd(dfd, filename, &stat); 	if (!error)		error = cp_new_stat(&stat, statbuf); out:	return error;}#endif asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf){	struct kstat stat;	int error = vfs_fstat(fd, &stat); 	if (!error)		error = cp_new_stat(&stat, statbuf); 	return error;} asmlinkage long sys_readlinkat(int dfd, const char __user *path,				char __user *buf, int bufsiz){	struct nameidata nd;	int error; 	if (bufsiz <= 0)		return -EINVAL; 	error = __user_walk_fd(dfd, path, 0, &nd);	if (!error) {		struct inode * inode = nd.dentry->d_inode; 		error = -EINVAL;		if (inode->i_op && inode->i_op->readlink) {			error = security_inode_readlink(nd.dentry);			if (!error) {				touch_atime(nd.mnt, nd.dentry);				error = inode->i_op->readlink(nd.dentry, buf, bufsiz);			}		}		path_release(&nd);	}	return error;} asmlinkage long sys_readlink(const char __user *path, char __user *buf,				int bufsiz){	return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);}  /* ---------- LFS-64 ----------- */#ifdef __ARCH_WANT_STAT64 static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf){	struct stat64 tmp; 	memset(&tmp, 0, sizeof(struct stat64));#ifdef CONFIG_MIPS	/* mips has weird padding, so we don't get 64 bits there */	if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))		return -EOVERFLOW;	tmp.st_dev = new_encode_dev(stat->dev);	tmp.st_rdev = new_encode_dev(stat->rdev);#else	tmp.st_dev = huge_encode_dev(stat->dev);	tmp.st_rdev = huge_encode_dev(stat->rdev);#endif	tmp.st_ino = stat->ino;#ifdef STAT64_HAS_BROKEN_ST_INO	tmp.__st_ino = stat->ino;#endif	tmp.st_mode = stat->mode;	tmp.st_nlink = stat->nlink;	tmp.st_uid = stat->uid;	tmp.st_gid = stat->gid;	tmp.st_atime = stat->atime.tv_sec;	tmp.st_atime_nsec = stat->atime.tv_nsec;	tmp.st_mtime = stat->mtime.tv_sec;	tmp.st_mtime_nsec = stat->mtime.tv_nsec;	tmp.st_ctime = stat->ctime.tv_sec;	tmp.st_ctime_nsec = stat->ctime.tv_nsec;	tmp.st_size = stat->size;	tmp.st_blocks = stat->blocks;	tmp.st_blksize = stat->blksize;	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;} asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf){	struct kstat stat;	int error = vfs_stat(filename, &stat); 	if (!error)		error = cp_new_stat64(&stat, statbuf); 	return error;}asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf){	struct kstat stat;	int error = vfs_lstat(filename, &stat); 	if (!error)		error = cp_new_stat64(&stat, statbuf); 	return error;}asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf){	struct kstat stat;	int error = vfs_fstat(fd, &stat); 	if (!error)		error = cp_new_stat64(&stat, statbuf); 	return error;} asmlinkage long sys_fstatat64(int dfd, char __user *filename,			       struct stat64 __user *statbuf, int flag){	struct kstat stat;	int error = -EINVAL; 	if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)		goto out; 	if (flag & AT_SYMLINK_NOFOLLOW)		error = vfs_lstat_fd(dfd, filename, &stat);	else		error = vfs_stat_fd(dfd, filename, &stat); 	if (!error)		error = cp_new_stat64(&stat, statbuf); out:	return error;}#endif /* __ARCH_WANT_STAT64 */ void inode_add_bytes(struct inode *inode, loff_t bytes){	spin_lock(&inode->i_lock);	inode->i_blocks += bytes >> 9;	bytes &= 511;	inode->i_bytes += bytes;	if (inode->i_bytes >= 512) {		inode->i_blocks++;		inode->i_bytes -= 512;	}	spin_unlock(&inode->i_lock);} EXPORT_SYMBOL(inode_add_bytes); void inode_sub_bytes(struct inode *inode, loff_t bytes){	spin_lock(&inode->i_lock);	inode->i_blocks -= bytes >> 9;	bytes &= 511;	if (inode->i_bytes < bytes) {		inode->i_blocks--;		inode->i_bytes += 512;	}	inode->i_bytes -= bytes;	spin_unlock(&inode->i_lock);} EXPORT_SYMBOL(inode_sub_bytes); loff_t inode_get_bytes(struct inode *inode){	loff_t ret; 	spin_lock(&inode->i_lock);	ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;	spin_unlock(&inode->i_lock);	return ret;} EXPORT_SYMBOL(inode_get_bytes); void inode_set_bytes(struct inode *inode, loff_t bytes){	/* Caller is here responsible for sufficient locking	 * (ie. inode->i_lock) */	inode->i_blocks = bytes >> 9;	inode->i_bytes = bytes & 511;} EXPORT_SYMBOL(inode_set_bytes);