File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/fs/stat.c b/fs/stat.c
new file mode 100644
index 0000000..004dd77
--- /dev/null
+++ b/fs/stat.c
@@ -0,0 +1,510 @@
+/*
+ * 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 = i_blocksize(inode);
+ 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 */
+ 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;
+ }
+}
+EXPORT_SYMBOL(__inode_add_bytes);
+
+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);