aufs: tiny, cosmetic level changes

Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>
(cherry picked from commit 0f5f91bda77d0690c23732fd2592ae97c908a704)

fs/aufs/dirren.c

@@ -68,7 +68,7 @@ int au_dr_hino_test_add(struct au_dr_br *dr, ino_t ino,
 	found = 0;
 	idx = au_dr_ihash(ino);
 	hbl = dr->dr_h_ino + idx;
-#if 0
+#if 0 /* debug print */
 	{
 		struct hlist_bl_node *tmp;
 

fs/aufs/f_op.c

@@ -317,7 +317,7 @@ static ssize_t au_do_iter(struct file *h_file, int rw, struct kiocb *kio,
 	if (unlikely(err))
 		goto out;
 
-	err = -ENOSYS;
+	err = -ENOSYS;	/* the branch doesn't have its ->(read|write)_iter() */
 	iter = NULL;
 	if (rw == MAY_READ)
 		iter = h_file->f_op->read_iter;
@@ -761,7 +761,7 @@ out:
 /* ---------------------------------------------------------------------- */
 
 /* no one supports this operation, currently */
-#if 0
+#if 0 /* reserved for future use */
 static ssize_t aufs_sendpage(struct file *file, struct page *page, int offset,
 			     size_t len, loff_t *pos, int more)
 {
@@ -797,7 +797,7 @@ const struct file_operations aufs_file_fop = {
 	.setfl		= aufs_setfl,
 	.splice_write	= aufs_splice_write,
 	.splice_read	= aufs_splice_read,
-#if 0
+#if 0 /* reserved for future use */
 	.aio_splice_write = aufs_aio_splice_write,
 	.aio_splice_read  = aufs_aio_splice_read,
 #endif

fs/aufs/hnotify.c

@@ -169,12 +169,6 @@ static int hn_gen_tree(struct dentry *dentry)
 
 out_dpages:
 	au_dpages_free(&dpages);
-
-#if 0
-	/* discard children */
-	dentry_unhash(dentry);
-	dput(dentry);
-#endif
 out:
 	return err;
 }

fs/aufs/i_op.c

@@ -59,19 +59,6 @@ static int h_permission(struct inode *h_inode, int mask,
 	if (!err)
 		err = security_inode_permission(h_inode, mask);
 
-#if 0
-	if (!err) {
-		/* todo: do we need to call ima_path_check()? */
-		struct path h_path = {
-			.dentry	=
-			.mnt	= h_mnt
-		};
-		err = ima_path_check(&h_path,
-				     mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
-				     IMA_COUNT_LEAVE);
-	}
-#endif
-
 out:
 	return err;
 }
@@ -93,7 +80,13 @@ static int aufs_permission(struct inode *inode, int mask)
 	sb = inode->i_sb;
 	si_read_lock(sb, AuLock_FLUSH);
 	ii_read_lock_child(inode);
-#if 0
+#if 0 /* reserved for future use */
+	/*
+	 * This test may be rather 'too much' since the test is essentially done
+	 * in the aufs_lookup().  Theoretically it is possible that the inode
+	 * generation doesn't match to the superblock's here.  But it isn't a
+	 * big deal I suppose.
+	 */
 	err = au_iigen_test(inode, au_sigen(sb));
 	if (unlikely(err))
 		goto out;
@@ -211,7 +204,7 @@ static struct dentry *aufs_lookup(struct inode *dir, struct dentry *dentry,
 	if (inode)
 		atomic_inc(&inode->i_count);
 	ret = d_splice_alias(inode, dentry);
-#if 0
+#if 0 /* reserved for future use */
 	if (unlikely(d_need_lookup(dentry))) {
 		spin_lock(&dentry->d_lock);
 		dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
@@ -627,7 +620,8 @@ out:
 
 static void au_pin_hdir_set_owner(struct au_pin *p, struct task_struct *task)
 {
-#if !defined(CONFIG_RWSEM_GENERIC_SPINLOCK) && defined(CONFIG_RWSEM_SPIN_ON_OWNER)
+#if !defined(CONFIG_RWSEM_GENERIC_SPINLOCK) \
+	&& defined(CONFIG_RWSEM_SPIN_ON_OWNER)
 	p->hdir->hi_inode->i_rwsem.owner = task;
 #endif
 }

fs/aufs/i_op_ren.c

@@ -402,7 +402,7 @@ static int do_rename(struct au_ren_args *a)
 	}
 
 	BUG_ON(d_is_positive(a->dst_h_dentry) && a->src_btop != a->btgt);
-#if 0
+#if 0 /* debugging */
 	BUG_ON(!au_ftest_ren(a->auren_flags, DIRREN)
 	       && d_is_positive(a->dst_h_dentry)
 	       && a->src_btop != a->btgt);

fs/aufs/inode.c

@@ -199,7 +199,7 @@ static int set_inode(struct inode *inode, struct dentry *dentry)
 	struct dentry *h_dentry;
 	struct inode *h_inode;
 	struct au_iinfo *iinfo;
-	struct inode_operations *iop;
+	const struct inode_operations *iop;
 
 	IiMustWriteLock(inode);
 

fs/aufs/inode.h

@@ -144,7 +144,7 @@ enum {
 	AuIop_OTHER,
 	AuIop_Last
 };
-extern struct inode_operations aufs_iop[AuIop_Last],
+extern struct inode_operations aufs_iop[AuIop_Last], /* not const */
 	aufs_iop_nogetattr[AuIop_Last];
 
 /* au_wr_dir flags */

fs/aufs/opts.c

@@ -1614,7 +1614,7 @@ int au_opts_verify(struct super_block *sb, unsigned long sb_flags,
 		if ((br->br_perm & AuBrAttr_ICEX)
 		    && !h_dir->i_op->listxattr)
 			br->br_perm &= ~AuBrAttr_ICEX;
-#if 0
+#if 0 /* untested */
 		if ((br->br_perm & AuBrAttr_ICEX_SEC)
 		    && (au_br_sb(br)->s_flags & SB_NOSEC))
 			br->br_perm &= ~AuBrAttr_ICEX_SEC;

fs/aufs/super.c

@@ -236,7 +236,7 @@ static int aufs_show_options(struct seq_file *m, struct dentry *dentry)
 	sb = dentry->d_sb;
 	if (sb->s_flags & SB_POSIXACL)
 		seq_puts(m, ",acl");
-#if 0
+#if 0 /* reserved for future use */
 	if (sb->s_flags & SB_I_VERSION)
 		seq_puts(m, ",i_version");
 #endif

fs/aufs/super.h

@@ -166,7 +166,7 @@ struct au_sbinfo {
 	struct hlist_bl_head	si_files;
 
 	/* with/without getattr, brother of sb->s_d_op */
-	struct inode_operations *si_iop_array;
+	const struct inode_operations *si_iop_array;
 
 	/*
 	 * sysfs and lifetime management.

fs/aufs/sysrq.c

@@ -21,6 +21,7 @@ static void sysrq_sb(struct super_block *sb)
 	struct hlist_bl_head *files;
 	struct hlist_bl_node *pos;
 	struct au_finfo *finfo;
+	struct inode *i;
 
 	plevel = au_plevel;
 	au_plevel = KERN_WARNING;
@@ -33,14 +34,7 @@ static void sysrq_sb(struct super_block *sb)
 	pr("superblock\n");
 	au_dpri_sb(sb);
 
-#if 0
-	pr("root dentry\n");
-	au_dpri_dentry(sb->s_root);
-	pr("root inode\n");
-	au_dpri_inode(d_inode(sb->s_root));
-#endif
-
-#if 0
+#if 0 /* reserved */
 	do {
 		int err, i, j, ndentry;
 		struct au_dcsub_pages dpages;
@@ -61,21 +55,16 @@ static void sysrq_sb(struct super_block *sb)
 	} while (0);
 #endif
 
-#if 1
-	{
-		struct inode *i;
-
-		pr("isolated inode\n");
-		spin_lock(&sb->s_inode_list_lock);
-		list_for_each_entry(i, &sb->s_inodes, i_sb_list) {
-			spin_lock(&i->i_lock);
-			if (1 || hlist_empty(&i->i_dentry))
-				au_dpri_inode(i);
-			spin_unlock(&i->i_lock);
-		}
-		spin_unlock(&sb->s_inode_list_lock);
+	pr("isolated inode\n");
+	spin_lock(&sb->s_inode_list_lock);
+	list_for_each_entry(i, &sb->s_inodes, i_sb_list) {
+		spin_lock(&i->i_lock);
+		if (hlist_empty(&i->i_dentry))
+			au_dpri_inode(i);
+		spin_unlock(&i->i_lock);
 	}
-#endif
+	spin_unlock(&sb->s_inode_list_lock);
+
 	pr("files\n");
 	files = &au_sbi(sb)->si_files;
 	hlist_bl_lock(files);

fs/aufs/vdir.c

@@ -82,7 +82,7 @@ int au_nhash_alloc(struct au_nhash *nhash, unsigned int num_hash, gfp_t gfp)
 
 static void nhash_count(struct hlist_head *head)
 {
-#if 0
+#if 0 /* debugging */
 	unsigned long n;
 	struct hlist_node *pos;
 

fs/aufs/whout.c

@@ -292,7 +292,7 @@ static int test_linkable(struct dentry *h_root)
 
 	pr_err("%pd (%s) doesn't support link(2), use noplink and rw+nolwh\n",
 	       h_root, au_sbtype(h_root->d_sb));
-	return -ENOSYS;
+	return -ENOSYS;	/* the branch doesn't have its ->link() */
 }
 
 /* todo: should this mkdir be done in /sbin/mount.aufs helper? */

fs/aufs/wkq.c

@@ -140,8 +140,8 @@ static int au_wkq_lockdep_alloc(struct au_wkinfo *wkinfo)
 		goto out;
 
 	err = 0;
-#if 0
-	if (0 && au_debug_test()) /* left for debugging */
+#if 0 /* left for debugging */
+	if (0 && au_debug_test())
 		lockdep_print_held_locks(curr);
 #endif
 	held_locks = curr->held_locks;
@@ -218,7 +218,6 @@ static void wkq_func(struct work_struct *wk)
 /*
  * Since struct completion is large, try allocating it dynamically.
  */
-#if 1 /* defined(CONFIG_4KSTACKS) || defined(AuTest4KSTACKS) */
 #define AuWkqCompDeclare(name)	struct completion *comp = NULL
 
 static int au_wkq_comp_alloc(struct au_wkinfo *wkinfo, struct completion **comp)
@@ -237,25 +236,6 @@ static void au_wkq_comp_free(struct completion *comp)
 	au_kfree_rcu(comp);
 }
 
-#else
-
-/* no braces */
-#define AuWkqCompDeclare(name) \
-	DECLARE_COMPLETION_ONSTACK(_ ## name); \
-	struct completion *comp = &_ ## name
-
-static int au_wkq_comp_alloc(struct au_wkinfo *wkinfo, struct completion **comp)
-{
-	wkinfo->comp = *comp;
-	return 0;
-}
-
-static void au_wkq_comp_free(struct completion *comp __maybe_unused)
-{
-	/* empty */
-}
-#endif /* 4KSTACKS */
-
 static void au_wkq_run(struct au_wkinfo *wkinfo)
 {
 	if (au_ftest_wkq(wkinfo->flags, NEST)) {

fs/aufs/xino.c

@@ -1342,7 +1342,7 @@ static void au_xino_release(struct kref *kref)
 	if (unlikely(ul)) {
 		pr_warn("xi_writing %lu\n", ul);
 		hlist_bl_lock(hbl);
-		hlist_bl_for_each_entry_safe (p, pos, n, hbl, node) {
+		hlist_bl_for_each_entry_safe(p, pos, n, hbl, node) {
 			hlist_bl_del(&p->node);
 			au_kfree_rcu(p);
 		}