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

Pull misc vfs updates from Al Viro:
 "Assorted stuff pile - no common topic here"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  whack-a-mole: don't open-code iminor/imajor
  9p: fix misuse of sscanf() in v9fs_stat2inode()
  audit_alloc_mark(): don't open-code ERR_CAST()
  fs/inode.c: make inode_init_always() initialize i_ino to 0
  vfs: don't unnecessarily clone write access for writable fds

5 files changed, 32 insertions, 48 deletions

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 648eb4c4cf7f..8d97f0b45e9c 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1139,9 +1139,6 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 		 struct super_block *sb, unsigned int flags)
 {
 	umode_t mode;
-	char ext[32];
-	char tag_name[14];
-	unsigned int i_nlink;
 	struct v9fs_session_info *v9ses = sb->s_fs_info;
 	struct v9fs_inode *v9inode = V9FS_I(inode);
 
@@ -1159,18 +1156,18 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 		inode->i_gid = stat->n_gid;
 	}
 	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
-		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
+		if (v9fs_proto_dotu(v9ses)) {
+			unsigned int i_nlink;
 			/*
-			 * Hadlink support got added later to
-			 * to the .u extension. So there can be
-			 * server out there that doesn't support
-			 * this even with .u extension. So check
-			 * for non NULL stat->extension
+			 * Hadlink support got added later to the .u extension.
+			 * So there can be a server out there that doesn't
+			 * support this even with .u extension. That would
+			 * just leave us with stat->extension being an empty
+			 * string, though.
 			 */
-			strlcpy(ext, stat->extension, sizeof(ext));
 			/* HARDLINKCOUNT %u */
-			sscanf(ext, "%13s %u", tag_name, &i_nlink);
-			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
+			if (sscanf(stat->extension,
+				   " HARDLINKCOUNT %u", &i_nlink) == 1)
 				set_nlink(inode, i_nlink);
 		}
 	}
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 68376fa03880..c9775d5c6594 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -491,8 +491,8 @@ static void init_dinode(struct gfs2_inode *dip, struct gfs2_inode *ip,
 	di = (struct gfs2_dinode *)dibh->b_data;
 	gfs2_dinode_out(ip, di);
 
-	di->di_major = cpu_to_be32(MAJOR(ip->i_inode.i_rdev));
-	di->di_minor = cpu_to_be32(MINOR(ip->i_inode.i_rdev));
+	di->di_major = cpu_to_be32(imajor(&ip->i_inode));
+	di->di_minor = cpu_to_be32(iminor(&ip->i_inode));
 	di->__pad1 = 0;
 	di->__pad2 = 0;
 	di->__pad3 = 0;
diff --git a/fs/inode.c b/fs/inode.c
index 6dba963d3f6d..a047ab306f9a 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -142,6 +142,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
 	atomic_set(&inode->i_count, 1);
 	inode->i_op = &empty_iops;
 	inode->i_fop = &no_open_fops;
+	inode->i_ino = 0;
 	inode->__i_nlink = 1;
 	inode->i_opflags = 0;
 	if (sb->s_xattr)
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index b2dc4d1f9dcc..1f0ffabbde56 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -551,7 +551,6 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 		ret = -ENOMEM;
 		goto out_unload;
 	}
-	inode->i_ino = 0;
 	inode->i_size = i_size_read(sb->s_bdev->bd_inode);
 	inode->i_mapping->a_ops = &jfs_metapage_aops;
 	inode_fake_hash(inode);
diff --git a/fs/namespace.c b/fs/namespace.c
index 062fe984a697..56bb5a5fdc0d 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -381,50 +381,36 @@ int mnt_want_write(struct vfsmount *m)
 EXPORT_SYMBOL_GPL(mnt_want_write);
 
 /**
- * mnt_clone_write - get write access to a mount
- * @mnt: the mount on which to take a write
- *
- * This is effectively like mnt_want_write, except
- * it must only be used to take an extra write reference
- * on a mountpoint that we already know has a write reference
- * on it. This allows some optimisation.
- *
- * After finished, mnt_drop_write must be called as usual to
- * drop the reference.
- */
-int mnt_clone_write(struct vfsmount *mnt)
-{
-	/* superblock may be r/o */
-	if (__mnt_is_readonly(mnt))
-		return -EROFS;
-	preempt_disable();
-	mnt_inc_writers(real_mount(mnt));
-	preempt_enable();
-	return 0;
-}
-EXPORT_SYMBOL_GPL(mnt_clone_write);
-
-/**
  * __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
+ * This is like __mnt_want_write, but if the file is already open for writing it
+ * skips incrementing mnt_writers (since the open file already has a reference)
+ * and instead only does the check for emergency r/o remounts.  This must be
+ * paired with __mnt_drop_write_file.
  */
 int __mnt_want_write_file(struct file *file)
 {
-	if (!(file->f_mode & FMODE_WRITER))
-		return __mnt_want_write(file->f_path.mnt);
-	else
-		return mnt_clone_write(file->f_path.mnt);
+	if (file->f_mode & FMODE_WRITER) {
+		/*
+		 * Superblock may have become readonly while there are still
+		 * writable fd's, e.g. due to a fs error with errors=remount-ro
+		 */
+		if (__mnt_is_readonly(file->f_path.mnt))
+			return -EROFS;
+		return 0;
+	}
+	return __mnt_want_write(file->f_path.mnt);
 }
 
 /**
  * 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
+ * This is like mnt_want_write, but if the file is already open for writing it
+ * skips incrementing mnt_writers (since the open file already has a reference)
+ * and instead only does the freeze protection and the check for emergency r/o
+ * remounts.  This must be paired with mnt_drop_write_file.
  */
 int mnt_want_write_file(struct file *file)
 {
@@ -470,7 +456,8 @@ EXPORT_SYMBOL_GPL(mnt_drop_write);
 
 void __mnt_drop_write_file(struct file *file)
 {
-	__mnt_drop_write(file->f_path.mnt);
+	if (!(file->f_mode & FMODE_WRITER))
+		__mnt_drop_write(file->f_path.mnt);
 }
 
 void mnt_drop_write_file(struct file *file)