From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 15 Sep 2017 03:01:41 +0000 (-0700)
Subject: Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
X-Git-Tag: v4.14-rc1~17
X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=9e0ce554b039e3df288d83189ecf226c16da04af;hp=-c

Merge branch 'work.misc' of git://git./linux/kernel/git/viro/vfs

Pull misc leftovers from Al Viro.

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix the __user misannotations in asm-generic get_user/put_user
  fput: Don't reinvent the wheel but use existing llist API
  namespace.c: Don't reinvent the wheel but use existing llist API
---

9e0ce554b039e3df288d83189ecf226c16da04af
diff --combined fs/namespace.c
index e48ad0192d81,ce82a5b2da12..54059b142d6b
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@@ -275,7 -275,7 +275,7 @@@ int __mnt_is_readonly(struct vfsmount *
  {
  	if (mnt->mnt_flags & MNT_READONLY)
  		return 1;
 -	if (mnt->mnt_sb->s_flags & MS_RDONLY)
 +	if (sb_rdonly(mnt->mnt_sb))
  		return 1;
  	return 0;
  }
@@@ -431,18 -431,13 +431,18 @@@ int __mnt_want_write_file(struct file *
  }
  
  /**
 - * mnt_want_write_file - get write access to a file's mount
 + * mnt_want_write_file_path - get write access to a file's mount
   * @file: the file who's mount on which to take a write
   *
   * This is like mnt_want_write, but it takes a file and can
   * do some optimisations if the file is open for write already
 + *
 + * Called by the vfs for cases when we have an open file at hand, but will do an
 + * inode operation on it (important distinction for files opened on overlayfs,
 + * since the file operations will come from the real underlying file, while
 + * inode operations come from the overlay).
   */
 -int mnt_want_write_file(struct file *file)
 +int mnt_want_write_file_path(struct file *file)
  {
  	int ret;
  
@@@ -452,53 -447,6 +452,53 @@@
  		sb_end_write(file->f_path.mnt->mnt_sb);
  	return ret;
  }
 +
 +static inline int may_write_real(struct file *file)
 +{
 +	struct dentry *dentry = file->f_path.dentry;
 +	struct dentry *upperdentry;
 +
 +	/* Writable file? */
 +	if (file->f_mode & FMODE_WRITER)
 +		return 0;
 +
 +	/* Not overlayfs? */
 +	if (likely(!(dentry->d_flags & DCACHE_OP_REAL)))
 +		return 0;
 +
 +	/* File refers to upper, writable layer? */
 +	upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER);
 +	if (upperdentry && file_inode(file) == d_inode(upperdentry))
 +		return 0;
 +
 +	/* Lower layer: can't write to real file, sorry... */
 +	return -EPERM;
 +}
 +
 +/**
 + * mnt_want_write_file - get write access to a file's mount
 + * @file: the file who's mount on which to take a write
 + *
 + * This is like mnt_want_write, but it takes a file and can
 + * do some optimisations if the file is open for write already
 + *
 + * Mostly called by filesystems from their ioctl operation before performing
 + * modification.  On overlayfs this needs to check if the file is on a read-only
 + * lower layer and deny access in that case.
 + */
 +int mnt_want_write_file(struct file *file)
 +{
 +	int ret;
 +
 +	ret = may_write_real(file);
 +	if (!ret) {
 +		sb_start_write(file_inode(file)->i_sb);
 +		ret = __mnt_want_write_file(file);
 +		if (ret)
 +			sb_end_write(file_inode(file)->i_sb);
 +	}
 +	return ret;
 +}
  EXPORT_SYMBOL_GPL(mnt_want_write_file);
  
  /**
@@@ -536,16 -484,10 +536,16 @@@ void __mnt_drop_write_file(struct file 
  	__mnt_drop_write(file->f_path.mnt);
  }
  
 -void mnt_drop_write_file(struct file *file)
 +void mnt_drop_write_file_path(struct file *file)
  {
  	mnt_drop_write(file->f_path.mnt);
  }
 +
 +void mnt_drop_write_file(struct file *file)
 +{
 +	__mnt_drop_write(file->f_path.mnt);
 +	sb_end_write(file_inode(file)->i_sb);
 +}
  EXPORT_SYMBOL(mnt_drop_write_file);
  
  static int mnt_make_readonly(struct mount *mnt)
@@@ -1029,7 -971,7 +1029,7 @@@ vfs_kern_mount(struct file_system_type 
  	if (!mnt)
  		return ERR_PTR(-ENOMEM);
  
 -	if (flags & MS_KERNMOUNT)
 +	if (flags & SB_KERNMOUNT)
  		mnt->mnt.mnt_flags = MNT_INTERNAL;
  
  	root = mount_fs(type, flags, name, data);
@@@ -1061,7 -1003,7 +1061,7 @@@ vfs_submount(const struct dentry *mount
  	if (mountpoint->d_sb->s_user_ns != &init_user_ns)
  		return ERR_PTR(-EPERM);
  
 -	return vfs_kern_mount(type, MS_SUBMOUNT, name, data);
 +	return vfs_kern_mount(type, SB_SUBMOUNT, name, data);
  }
  EXPORT_SYMBOL_GPL(vfs_submount);
  
@@@ -1182,12 -1124,10 +1182,10 @@@ static LLIST_HEAD(delayed_mntput_list)
  static void delayed_mntput(struct work_struct *unused)
  {
  	struct llist_node *node = llist_del_all(&delayed_mntput_list);
- 	struct llist_node *next;
+ 	struct mount *m, *t;
  
- 	for (; node; node = next) {
- 		next = llist_next(node);
- 		cleanup_mnt(llist_entry(node, struct mount, mnt_llist));
- 	}
+ 	llist_for_each_entry_safe(m, t, node, mnt_llist)
+ 		cleanup_mnt(m);
  }
  static DECLARE_DELAYED_WORK(delayed_mntput_work, delayed_mntput);
  
@@@ -1592,8 -1532,8 +1590,8 @@@ static int do_umount(struct mount *mnt
  		if (!capable(CAP_SYS_ADMIN))
  			return -EPERM;
  		down_write(&sb->s_umount);
 -		if (!(sb->s_flags & MS_RDONLY))
 -			retval = do_remount_sb(sb, MS_RDONLY, NULL, 0);
 +		if (!sb_rdonly(sb))
 +			retval = do_remount_sb(sb, SB_RDONLY, NULL, 0);
  		up_write(&sb->s_umount);
  		return retval;
  	}
@@@ -2117,7 -2057,7 +2115,7 @@@ static void unlock_mount(struct mountpo
  
  static int graft_tree(struct mount *mnt, struct mount *p, struct mountpoint *mp)
  {
 -	if (mnt->mnt.mnt_sb->s_flags & MS_NOUSER)
 +	if (mnt->mnt.mnt_sb->s_flags & SB_NOUSER)
  		return -EINVAL;
  
  	if (d_is_dir(mp->m_dentry) !=
@@@ -2131,9 -2071,9 +2129,9 @@@
   * Sanity check the flags to change_mnt_propagation.
   */
  
 -static int flags_to_propagation_type(int flags)
 +static int flags_to_propagation_type(int ms_flags)
  {
 -	int type = flags & ~(MS_REC | MS_SILENT);
 +	int type = ms_flags & ~(MS_REC | MS_SILENT);
  
  	/* Fail if any non-propagation flags are set */
  	if (type & ~(MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
@@@ -2147,18 -2087,18 +2145,18 @@@
  /*
   * recursively change the type of the mountpoint.
   */
 -static int do_change_type(struct path *path, int flag)
 +static int do_change_type(struct path *path, int ms_flags)
  {
  	struct mount *m;
  	struct mount *mnt = real_mount(path->mnt);
 -	int recurse = flag & MS_REC;
 +	int recurse = ms_flags & MS_REC;
  	int type;
  	int err = 0;
  
  	if (path->dentry != path->mnt->mnt_root)
  		return -EINVAL;
  
 -	type = flags_to_propagation_type(flag);
 +	type = flags_to_propagation_type(ms_flags);
  	if (!type)
  		return -EINVAL;
  
@@@ -2280,8 -2220,8 +2278,8 @@@ static int change_mount_flags(struct vf
   * If you've mounted a non-root directory somewhere and want to do remount
   * on it - tough luck.
   */
 -static int do_remount(struct path *path, int flags, int mnt_flags,
 -		      void *data)
 +static int do_remount(struct path *path, int ms_flags, int sb_flags,
 +		      int mnt_flags, void *data)
  {
  	int err;
  	struct super_block *sb = path->mnt->mnt_sb;
@@@ -2325,12 -2265,12 +2323,12 @@@
  		return err;
  
  	down_write(&sb->s_umount);
 -	if (flags & MS_BIND)
 -		err = change_mount_flags(path->mnt, flags);
 +	if (ms_flags & MS_BIND)
 +		err = change_mount_flags(path->mnt, ms_flags);
  	else if (!capable(CAP_SYS_ADMIN))
  		err = -EPERM;
  	else
 -		err = do_remount_sb(sb, flags, data, 0);
 +		err = do_remount_sb(sb, sb_flags, data, 0);
  	if (!err) {
  		lock_mount_hash();
  		mnt_flags |= mnt->mnt.mnt_flags & ~MNT_USER_SETTABLE_MASK;
@@@ -2495,7 -2435,7 +2493,7 @@@ static bool mount_too_revealing(struct 
   * create a new mount for userspace and request it to be added into the
   * namespace's tree
   */
 -static int do_new_mount(struct path *path, const char *fstype, int flags,
 +static int do_new_mount(struct path *path, const char *fstype, int sb_flags,
  			int mnt_flags, const char *name, void *data)
  {
  	struct file_system_type *type;
@@@ -2509,7 -2449,7 +2507,7 @@@
  	if (!type)
  		return -ENODEV;
  
 -	mnt = vfs_kern_mount(type, flags, name, data);
 +	mnt = vfs_kern_mount(type, sb_flags, name, data);
  	if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
  	    !mnt->mnt_sb->s_subtype)
  		mnt = fs_set_subtype(mnt, fstype);
@@@ -2764,8 -2704,8 +2762,8 @@@ long do_mount(const char *dev_name, con
  		const char *type_page, unsigned long flags, void *data_page)
  {
  	struct path path;
 +	unsigned int mnt_flags = 0, sb_flags;
  	int retval = 0;
 -	int mnt_flags = 0;
  
  	/* Discard magic */
  	if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
@@@ -2775,9 -2715,6 +2773,9 @@@
  	if (data_page)
  		((char *)data_page)[PAGE_SIZE - 1] = 0;
  
 +	if (flags & MS_NOUSER)
 +		return -EINVAL;
 +
  	/* ... and get the mountpoint */
  	retval = user_path(dir_name, &path);
  	if (retval)
@@@ -2787,7 -2724,7 +2785,7 @@@
  				   type_page, flags, data_page);
  	if (!retval && !may_mount())
  		retval = -EPERM;
 -	if (!retval && (flags & MS_MANDLOCK) && !may_mandlock())
 +	if (!retval && (flags & SB_MANDLOCK) && !may_mandlock())
  		retval = -EPERM;
  	if (retval)
  		goto dput_out;
@@@ -2809,7 -2746,7 +2807,7 @@@
  		mnt_flags |= MNT_NODIRATIME;
  	if (flags & MS_STRICTATIME)
  		mnt_flags &= ~(MNT_RELATIME | MNT_NOATIME);
 -	if (flags & MS_RDONLY)
 +	if (flags & SB_RDONLY)
  		mnt_flags |= MNT_READONLY;
  
  	/* The default atime for remount is preservation */
@@@ -2820,15 -2757,12 +2818,15 @@@
  		mnt_flags |= path.mnt->mnt_flags & MNT_ATIME_MASK;
  	}
  
 -	flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | MS_BORN |
 -		   MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT |
 -		   MS_STRICTATIME | MS_NOREMOTELOCK | MS_SUBMOUNT);
 +	sb_flags = flags & (SB_RDONLY |
 +			    SB_SYNCHRONOUS |
 +			    SB_MANDLOCK |
 +			    SB_DIRSYNC |
 +			    SB_SILENT |
 +			    SB_POSIXACL);
  
  	if (flags & MS_REMOUNT)
 -		retval = do_remount(&path, flags & ~MS_REMOUNT, mnt_flags,
 +		retval = do_remount(&path, flags, sb_flags, mnt_flags,
  				    data_page);
  	else if (flags & MS_BIND)
  		retval = do_loopback(&path, dev_name, flags & MS_REC);
@@@ -2837,7 -2771,7 +2835,7 @@@
  	else if (flags & MS_MOVE)
  		retval = do_move_mount(&path, dev_name);
  	else
 -		retval = do_new_mount(&path, type_page, flags, mnt_flags,
 +		retval = do_new_mount(&path, type_page, sb_flags, mnt_flags,
  				      dev_name, data_page);
  dput_out:
  	path_put(&path);
@@@ -3287,7 -3221,7 +3285,7 @@@ void put_mnt_ns(struct mnt_namespace *n
  struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
  {
  	struct vfsmount *mnt;
 -	mnt = vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
 +	mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, data);
  	if (!IS_ERR(mnt)) {
  		/*
  		 * it is a longterm mount, don't release mnt until
@@@ -3364,7 -3298,7 +3362,7 @@@ static bool mnt_already_visible(struct 
  		mnt_flags = mnt->mnt.mnt_flags;
  
  		/* Don't miss readonly hidden in the superblock flags */
 -		if (mnt->mnt.mnt_sb->s_flags & MS_RDONLY)
 +		if (sb_rdonly(mnt->mnt.mnt_sb))
  			mnt_flags |= MNT_LOCK_READONLY;
  
  		/* Verify the mount flags are equal to or more permissive