Initial import

1 files changed, 511 insertions, 0 deletions

diff --git a/fs/stat.c b/fs/stat.c
new file mode 100644
index 000000000..cccc1aab9
--- /dev/null
+++ b/fs/stat.c
@@ -0,0 +1,511 @@
+/*
+ *  linux/fs/stat.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/highuid.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/pagemap.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->size = i_size_read(inode);
+	stat->atime = inode->i_atime;
+	stat->mtime = inode->i_mtime;
+	stat->ctime = inode->i_ctime;
+	stat->blksize = (1 << inode->i_blkbits);
+	stat->blocks = inode->i_blocks;
+}
+
+EXPORT_SYMBOL(generic_fillattr);
+
+/**
+ * vfs_getattr_nosec - getattr without security checks
+ * @path: file to get attributes from
+ * @stat: structure to return attributes in
+ *
+ * Get attributes without calling security_inode_getattr.
+ *
+ * Currently the only caller other than vfs_getattr is internal to the
+ * filehandle lookup code, which uses only the inode number and returns
+ * no attributes to any user.  Any other code probably wants
+ * vfs_getattr.
+ */
+int vfs_getattr_nosec(struct path *path, struct kstat *stat)
+{
+	struct inode *inode = d_backing_inode(path->dentry);
+
+	if (inode->i_op->getattr)
+		return inode->i_op->getattr(path->mnt, path->dentry, stat);
+
+	generic_fillattr(inode, stat);
+	return 0;
+}
+
+EXPORT_SYMBOL(vfs_getattr_nosec);
+
+int vfs_getattr(struct path *path, struct kstat *stat)
+{
+	int retval;
+
+	retval = security_inode_getattr(path);
+	if (retval)
+		return retval;
+	return vfs_getattr_nosec(path, stat);
+}
+
+EXPORT_SYMBOL(vfs_getattr);
+
+int vfs_fstat(unsigned int fd, struct kstat *stat)
+{
+	struct fd f = fdget_raw(fd);
+	int error = -EBADF;
+
+	if (f.file) {
+		error = vfs_getattr(&f.file->f_path, stat);
+		fdput(f);
+	}
+	return error;
+}
+EXPORT_SYMBOL(vfs_fstat);
+
+int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
+		int flag)
+{
+	struct path path;
+	int error = -EINVAL;
+	unsigned int lookup_flags = 0;
+
+	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
+		      AT_EMPTY_PATH)) != 0)
+		goto out;
+
+	if (!(flag & AT_SYMLINK_NOFOLLOW))
+		lookup_flags |= LOOKUP_FOLLOW;
+	if (flag & AT_EMPTY_PATH)
+		lookup_flags |= LOOKUP_EMPTY;
+retry:
+	error = user_path_at(dfd, filename, lookup_flags, &path);
+	if (error)
+		goto out;
+
+	error = vfs_getattr(&path, stat);
+	path_put(&path);
+	if (retry_estale(error, lookup_flags)) {
+		lookup_flags |= LOOKUP_REVAL;
+		goto retry;
+	}
+out:
+	return error;
+}
+EXPORT_SYMBOL(vfs_fstatat);
+
+int vfs_stat(const char __user *name, struct kstat *stat)
+{
+	return vfs_fstatat(AT_FDCWD, name, stat, 0);
+}
+EXPORT_SYMBOL(vfs_stat);
+
+int vfs_lstat(const char __user *name, struct kstat *stat)
+{
+	return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
+}
+EXPORT_SYMBOL(vfs_lstat);
+
+
+#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;
+	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
+		return -EOVERFLOW;
+	tmp.st_mode = stat->mode;
+	tmp.st_nlink = stat->nlink;
+	if (tmp.st_nlink != stat->nlink)
+		return -EOVERFLOW;
+	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
+	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), 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;
+}
+
+SYSCALL_DEFINE2(stat, const char __user *, filename,
+		struct __old_kernel_stat __user *, statbuf)
+{
+	struct kstat stat;
+	int error;
+
+	error = vfs_stat(filename, &stat);
+	if (error)
+		return error;
+
+	return cp_old_stat(&stat, statbuf);
+}
+
+SYSCALL_DEFINE2(lstat, const char __user *, filename,
+		struct __old_kernel_stat __user *, statbuf)
+{
+	struct kstat stat;
+	int error;
+
+	error = vfs_lstat(filename, &stat);
+	if (error)
+		return error;
+
+	return cp_old_stat(&stat, statbuf);
+}
+
+SYSCALL_DEFINE2(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 */
+
+#if BITS_PER_LONG == 32
+#  define choose_32_64(a,b) a
+#else
+#  define choose_32_64(a,b) b
+#endif
+
+#define valid_dev(x)  choose_32_64(old_valid_dev,new_valid_dev)(x)
+#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
+
+#ifndef INIT_STRUCT_STAT_PADDING
+#  define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
+#endif
+
+static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
+{
+	struct stat tmp;
+
+	if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
+		return -EOVERFLOW;
+#if BITS_PER_LONG == 32
+	if (stat->size > MAX_NON_LFS)
+		return -EOVERFLOW;
+#endif
+
+	INIT_STRUCT_STAT_PADDING(tmp);
+	tmp.st_dev = encode_dev(stat->dev);
+	tmp.st_ino = stat->ino;
+	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
+		return -EOVERFLOW;
+	tmp.st_mode = stat->mode;
+	tmp.st_nlink = stat->nlink;
+	if (tmp.st_nlink != stat->nlink)
+		return -EOVERFLOW;
+	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
+	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
+	tmp.st_rdev = encode_dev(stat->rdev);
+	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;
+}
+
+SYSCALL_DEFINE2(newstat, const char __user *, filename,
+		struct stat __user *, statbuf)
+{
+	struct kstat stat;
+	int error = vfs_stat(filename, &stat);
+
+	if (error)
+		return error;
+	return cp_new_stat(&stat, statbuf);
+}
+
+SYSCALL_DEFINE2(newlstat, const char __user *, filename,
+		struct stat __user *, statbuf)
+{
+	struct kstat stat;
+	int error;
+
+	error = vfs_lstat(filename, &stat);
+	if (error)
+		return error;
+
+	return cp_new_stat(&stat, statbuf);
+}
+
+#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
+SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
+		struct stat __user *, statbuf, int, flag)
+{
+	struct kstat stat;
+	int error;
+
+	error = vfs_fstatat(dfd, filename, &stat, flag);
+	if (error)
+		return error;
+	return cp_new_stat(&stat, statbuf);
+}
+#endif
+
+SYSCALL_DEFINE2(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;
+}
+
+SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
+		char __user *, buf, int, bufsiz)
+{
+	struct path path;
+	int error;
+	int empty = 0;
+	unsigned int lookup_flags = LOOKUP_EMPTY;
+
+	if (bufsiz <= 0)
+		return -EINVAL;
+
+retry:
+	error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
+	if (!error) {
+		struct inode *inode = d_backing_inode(path.dentry);
+
+		error = empty ? -ENOENT : -EINVAL;
+		if (inode->i_op->readlink) {
+			error = security_inode_readlink(path.dentry);
+			if (!error) {
+				touch_atime(&path);
+				error = inode->i_op->readlink(path.dentry,
+							      buf, bufsiz);
+			}
+		}
+		path_put(&path);
+		if (retry_estale(error, lookup_flags)) {
+			lookup_flags |= LOOKUP_REVAL;
+			goto retry;
+		}
+	}
+	return error;
+}
+
+SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
+		int, bufsiz)
+{
+	return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
+}
+
+
+/* ---------- LFS-64 ----------- */
+#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
+
+#ifndef INIT_STRUCT_STAT64_PADDING
+#  define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
+#endif
+
+static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
+{
+	struct stat64 tmp;
+
+	INIT_STRUCT_STAT64_PADDING(tmp);
+#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;
+	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
+		return -EOVERFLOW;
+#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 = from_kuid_munged(current_user_ns(), stat->uid);
+	tmp.st_gid = from_kgid_munged(current_user_ns(), 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;
+}
+
+SYSCALL_DEFINE2(stat64, const 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;
+}
+
+SYSCALL_DEFINE2(lstat64, const 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;
+}
+
+SYSCALL_DEFINE2(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;
+}
+
+SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
+		struct stat64 __user *, statbuf, int, flag)
+{
+	struct kstat stat;
+	int error;
+
+	error = vfs_fstatat(dfd, filename, &stat, flag);
+	if (error)
+		return error;
+	return cp_new_stat64(&stat, statbuf);
+}
+#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
+
+/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
+void __inode_add_bytes(struct inode *inode, loff_t bytes)
+{
+	inode->i_blocks += bytes >> 9;
+	bytes &= 511;
+	inode->i_bytes += bytes;
+	if (inode->i_bytes >= 512) {
+		inode->i_blocks++;
+		inode->i_bytes -= 512;
+	}
+}
+
+void inode_add_bytes(struct inode *inode, loff_t bytes)
+{
+	spin_lock(&inode->i_lock);
+	__inode_add_bytes(inode, bytes);
+	spin_unlock(&inode->i_lock);
+}
+
+EXPORT_SYMBOL(inode_add_bytes);
+
+void __inode_sub_bytes(struct inode *inode, loff_t bytes)
+{
+	inode->i_blocks -= bytes >> 9;
+	bytes &= 511;
+	if (inode->i_bytes < bytes) {
+		inode->i_blocks--;
+		inode->i_bytes += 512;
+	}
+	inode->i_bytes -= bytes;
+}
+
+EXPORT_SYMBOL(__inode_sub_bytes);
+
+void inode_sub_bytes(struct inode *inode, loff_t bytes)
+{
+	spin_lock(&inode->i_lock);
+	__inode_sub_bytes(inode, 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);