v4.19.13 snapshot.
diff --git a/fs/statfs.c b/fs/statfs.c
new file mode 100644
index 0000000..f021662
--- /dev/null
+++ b/fs/statfs.c
@@ -0,0 +1,396 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/syscalls.h>
+#include <linux/export.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/statfs.h>
+#include <linux/security.h>
+#include <linux/uaccess.h>
+#include <linux/compat.h>
+#include "internal.h"
+
+static int flags_by_mnt(int mnt_flags)
+{
+ int flags = 0;
+
+ if (mnt_flags & MNT_READONLY)
+ flags |= ST_RDONLY;
+ if (mnt_flags & MNT_NOSUID)
+ flags |= ST_NOSUID;
+ if (mnt_flags & MNT_NODEV)
+ flags |= ST_NODEV;
+ if (mnt_flags & MNT_NOEXEC)
+ flags |= ST_NOEXEC;
+ if (mnt_flags & MNT_NOATIME)
+ flags |= ST_NOATIME;
+ if (mnt_flags & MNT_NODIRATIME)
+ flags |= ST_NODIRATIME;
+ if (mnt_flags & MNT_RELATIME)
+ flags |= ST_RELATIME;
+ return flags;
+}
+
+static int flags_by_sb(int s_flags)
+{
+ int flags = 0;
+ if (s_flags & SB_SYNCHRONOUS)
+ flags |= ST_SYNCHRONOUS;
+ if (s_flags & SB_MANDLOCK)
+ flags |= ST_MANDLOCK;
+ if (s_flags & SB_RDONLY)
+ flags |= ST_RDONLY;
+ return flags;
+}
+
+static int calculate_f_flags(struct vfsmount *mnt)
+{
+ return ST_VALID | flags_by_mnt(mnt->mnt_flags) |
+ flags_by_sb(mnt->mnt_sb->s_flags);
+}
+
+static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
+{
+ int retval;
+
+ if (!dentry->d_sb->s_op->statfs)
+ return -ENOSYS;
+
+ memset(buf, 0, sizeof(*buf));
+ retval = security_sb_statfs(dentry);
+ if (retval)
+ return retval;
+ retval = dentry->d_sb->s_op->statfs(dentry, buf);
+ if (retval == 0 && buf->f_frsize == 0)
+ buf->f_frsize = buf->f_bsize;
+ return retval;
+}
+
+int vfs_statfs(const struct path *path, struct kstatfs *buf)
+{
+ int error;
+
+ error = statfs_by_dentry(path->dentry, buf);
+ if (!error)
+ buf->f_flags = calculate_f_flags(path->mnt);
+ return error;
+}
+EXPORT_SYMBOL(vfs_statfs);
+
+int user_statfs(const char __user *pathname, struct kstatfs *st)
+{
+ struct path path;
+ int error;
+ unsigned int lookup_flags = LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
+ if (!error) {
+ error = vfs_statfs(&path, st);
+ path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
+ }
+ return error;
+}
+
+int fd_statfs(int fd, struct kstatfs *st)
+{
+ struct fd f = fdget_raw(fd);
+ int error = -EBADF;
+ if (f.file) {
+ error = vfs_statfs(&f.file->f_path, st);
+ fdput(f);
+ }
+ return error;
+}
+
+static int do_statfs_native(struct kstatfs *st, struct statfs __user *p)
+{
+ struct statfs buf;
+
+ if (sizeof(buf) == sizeof(*st))
+ memcpy(&buf, st, sizeof(*st));
+ else {
+ if (sizeof buf.f_blocks == 4) {
+ if ((st->f_blocks | st->f_bfree | st->f_bavail |
+ st->f_bsize | st->f_frsize) &
+ 0xffffffff00000000ULL)
+ return -EOVERFLOW;
+ /*
+ * f_files and f_ffree may be -1; it's okay to stuff
+ * that into 32 bits
+ */
+ if (st->f_files != -1 &&
+ (st->f_files & 0xffffffff00000000ULL))
+ return -EOVERFLOW;
+ if (st->f_ffree != -1 &&
+ (st->f_ffree & 0xffffffff00000000ULL))
+ return -EOVERFLOW;
+ }
+
+ buf.f_type = st->f_type;
+ buf.f_bsize = st->f_bsize;
+ buf.f_blocks = st->f_blocks;
+ buf.f_bfree = st->f_bfree;
+ buf.f_bavail = st->f_bavail;
+ buf.f_files = st->f_files;
+ buf.f_ffree = st->f_ffree;
+ buf.f_fsid = st->f_fsid;
+ buf.f_namelen = st->f_namelen;
+ buf.f_frsize = st->f_frsize;
+ buf.f_flags = st->f_flags;
+ memset(buf.f_spare, 0, sizeof(buf.f_spare));
+ }
+ if (copy_to_user(p, &buf, sizeof(buf)))
+ return -EFAULT;
+ return 0;
+}
+
+static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p)
+{
+ struct statfs64 buf;
+ if (sizeof(buf) == sizeof(*st))
+ memcpy(&buf, st, sizeof(*st));
+ else {
+ buf.f_type = st->f_type;
+ buf.f_bsize = st->f_bsize;
+ buf.f_blocks = st->f_blocks;
+ buf.f_bfree = st->f_bfree;
+ buf.f_bavail = st->f_bavail;
+ buf.f_files = st->f_files;
+ buf.f_ffree = st->f_ffree;
+ buf.f_fsid = st->f_fsid;
+ buf.f_namelen = st->f_namelen;
+ buf.f_frsize = st->f_frsize;
+ buf.f_flags = st->f_flags;
+ memset(buf.f_spare, 0, sizeof(buf.f_spare));
+ }
+ if (copy_to_user(p, &buf, sizeof(buf)))
+ return -EFAULT;
+ return 0;
+}
+
+SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf)
+{
+ struct kstatfs st;
+ int error = user_statfs(pathname, &st);
+ if (!error)
+ error = do_statfs_native(&st, buf);
+ return error;
+}
+
+SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf)
+{
+ struct kstatfs st;
+ int error;
+ if (sz != sizeof(*buf))
+ return -EINVAL;
+ error = user_statfs(pathname, &st);
+ if (!error)
+ error = do_statfs64(&st, buf);
+ return error;
+}
+
+SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
+{
+ struct kstatfs st;
+ int error = fd_statfs(fd, &st);
+ if (!error)
+ error = do_statfs_native(&st, buf);
+ return error;
+}
+
+SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
+{
+ struct kstatfs st;
+ int error;
+
+ if (sz != sizeof(*buf))
+ return -EINVAL;
+
+ error = fd_statfs(fd, &st);
+ if (!error)
+ error = do_statfs64(&st, buf);
+ return error;
+}
+
+static int vfs_ustat(dev_t dev, struct kstatfs *sbuf)
+{
+ struct super_block *s = user_get_super(dev);
+ int err;
+ if (!s)
+ return -EINVAL;
+
+ err = statfs_by_dentry(s->s_root, sbuf);
+ drop_super(s);
+ return err;
+}
+
+SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
+{
+ struct ustat tmp;
+ struct kstatfs sbuf;
+ int err = vfs_ustat(new_decode_dev(dev), &sbuf);
+ if (err)
+ return err;
+
+ memset(&tmp,0,sizeof(struct ustat));
+ tmp.f_tfree = sbuf.f_bfree;
+ tmp.f_tinode = sbuf.f_ffree;
+
+ return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0;
+}
+
+#ifdef CONFIG_COMPAT
+static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *kbuf)
+{
+ struct compat_statfs buf;
+ if (sizeof ubuf->f_blocks == 4) {
+ if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail |
+ kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL)
+ return -EOVERFLOW;
+ /* f_files and f_ffree may be -1; it's okay
+ * to stuff that into 32 bits */
+ if (kbuf->f_files != 0xffffffffffffffffULL
+ && (kbuf->f_files & 0xffffffff00000000ULL))
+ return -EOVERFLOW;
+ if (kbuf->f_ffree != 0xffffffffffffffffULL
+ && (kbuf->f_ffree & 0xffffffff00000000ULL))
+ return -EOVERFLOW;
+ }
+ memset(&buf, 0, sizeof(struct compat_statfs));
+ buf.f_type = kbuf->f_type;
+ buf.f_bsize = kbuf->f_bsize;
+ buf.f_blocks = kbuf->f_blocks;
+ buf.f_bfree = kbuf->f_bfree;
+ buf.f_bavail = kbuf->f_bavail;
+ buf.f_files = kbuf->f_files;
+ buf.f_ffree = kbuf->f_ffree;
+ buf.f_namelen = kbuf->f_namelen;
+ buf.f_fsid.val[0] = kbuf->f_fsid.val[0];
+ buf.f_fsid.val[1] = kbuf->f_fsid.val[1];
+ buf.f_frsize = kbuf->f_frsize;
+ buf.f_flags = kbuf->f_flags;
+ if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs)))
+ return -EFAULT;
+ return 0;
+}
+
+/*
+ * The following statfs calls are copies of code from fs/statfs.c and
+ * should be checked against those from time to time
+ */
+COMPAT_SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct compat_statfs __user *, buf)
+{
+ struct kstatfs tmp;
+ int error = user_statfs(pathname, &tmp);
+ if (!error)
+ error = put_compat_statfs(buf, &tmp);
+ return error;
+}
+
+COMPAT_SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct compat_statfs __user *, buf)
+{
+ struct kstatfs tmp;
+ int error = fd_statfs(fd, &tmp);
+ if (!error)
+ error = put_compat_statfs(buf, &tmp);
+ return error;
+}
+
+static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf)
+{
+ struct compat_statfs64 buf;
+ if (sizeof(ubuf->f_bsize) == 4) {
+ if ((kbuf->f_type | kbuf->f_bsize | kbuf->f_namelen |
+ kbuf->f_frsize | kbuf->f_flags) & 0xffffffff00000000ULL)
+ return -EOVERFLOW;
+ /* f_files and f_ffree may be -1; it's okay
+ * to stuff that into 32 bits */
+ if (kbuf->f_files != 0xffffffffffffffffULL
+ && (kbuf->f_files & 0xffffffff00000000ULL))
+ return -EOVERFLOW;
+ if (kbuf->f_ffree != 0xffffffffffffffffULL
+ && (kbuf->f_ffree & 0xffffffff00000000ULL))
+ return -EOVERFLOW;
+ }
+ memset(&buf, 0, sizeof(struct compat_statfs64));
+ buf.f_type = kbuf->f_type;
+ buf.f_bsize = kbuf->f_bsize;
+ buf.f_blocks = kbuf->f_blocks;
+ buf.f_bfree = kbuf->f_bfree;
+ buf.f_bavail = kbuf->f_bavail;
+ buf.f_files = kbuf->f_files;
+ buf.f_ffree = kbuf->f_ffree;
+ buf.f_namelen = kbuf->f_namelen;
+ buf.f_fsid.val[0] = kbuf->f_fsid.val[0];
+ buf.f_fsid.val[1] = kbuf->f_fsid.val[1];
+ buf.f_frsize = kbuf->f_frsize;
+ buf.f_flags = kbuf->f_flags;
+ if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs64)))
+ return -EFAULT;
+ return 0;
+}
+
+int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz, struct compat_statfs64 __user * buf)
+{
+ struct kstatfs tmp;
+ int error;
+
+ if (sz != sizeof(*buf))
+ return -EINVAL;
+
+ error = user_statfs(pathname, &tmp);
+ if (!error)
+ error = put_compat_statfs64(buf, &tmp);
+ return error;
+}
+
+COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf)
+{
+ return kcompat_sys_statfs64(pathname, sz, buf);
+}
+
+int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user * buf)
+{
+ struct kstatfs tmp;
+ int error;
+
+ if (sz != sizeof(*buf))
+ return -EINVAL;
+
+ error = fd_statfs(fd, &tmp);
+ if (!error)
+ error = put_compat_statfs64(buf, &tmp);
+ return error;
+}
+
+COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf)
+{
+ return kcompat_sys_fstatfs64(fd, sz, buf);
+}
+
+/*
+ * This is a copy of sys_ustat, just dealing with a structure layout.
+ * Given how simple this syscall is that apporach is more maintainable
+ * than the various conversion hacks.
+ */
+COMPAT_SYSCALL_DEFINE2(ustat, unsigned, dev, struct compat_ustat __user *, u)
+{
+ struct compat_ustat tmp;
+ struct kstatfs sbuf;
+ int err = vfs_ustat(new_decode_dev(dev), &sbuf);
+ if (err)
+ return err;
+
+ memset(&tmp, 0, sizeof(struct compat_ustat));
+ tmp.f_tfree = sbuf.f_bfree;
+ tmp.f_tinode = sbuf.f_ffree;
+ if (copy_to_user(u, &tmp, sizeof(struct compat_ustat)))
+ return -EFAULT;
+ return 0;
+}
+#endif