knfsd: exportfs: add find_disconnected_root helper

Break the loop that finds the root of a disconnected subtree into a helper of its own to make reading easier and document the intent. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

knfsd: exportfs: add find_disconnected_root helper
Break the loop that finds the root of a disconnected subtree into a helper of its own to make reading easier and document the intent. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig · Linus Torvalds
1 parent fb66a1989c
Showing 1 changed file with 23 additions and 16 deletions Side-by-side Diff
fs/exportfs/expfs.c
@@ -70,6 +70,27 @@
 	return NULL;
 }
  
+/*
+ * Find root of a disconnected subtree and return a reference to it.
+ */
+static struct dentry *
+find_disconnected_root(struct dentry *dentry)
+{
+	dget(dentry);
+	spin_lock(&dentry->d_lock);
+	while (!IS_ROOT(dentry) &&
+	       (dentry->d_parent->d_flags & DCACHE_DISCONNECTED)) {
+		struct dentry *parent = dentry->d_parent;
+		dget(parent);
+		spin_unlock(&dentry->d_lock);
+		dput(dentry);
+		dentry = parent;
+		spin_lock(&dentry->d_lock);
+	}
+	spin_unlock(&dentry->d_lock);
+	return dentry;
+}
+
 /**
  * find_exported_dentry - helper routine to implement export_operations->decode_fh
  * @sb:		The &super_block identifying the filesystem
  
@@ -164,23 +185,9 @@
 	 * the noprogress counter.  If we go through the loop 10 times (2 is
 	 * probably enough) without getting anywhere, we just give up
 	 */
-	noprogress= 0;
+	noprogress = 0;
 	while (target_dir->d_flags & DCACHE_DISCONNECTED && noprogress++ < 10) {
-		struct dentry *pd = target_dir;
-
-		dget(pd);
-		spin_lock(&pd->d_lock);
-		while (!IS_ROOT(pd) &&
-				(pd->d_parent->d_flags&DCACHE_DISCONNECTED)) {
-			struct dentry *parent = pd->d_parent;
-
-			dget(parent);
-			spin_unlock(&pd->d_lock);
-			dput(pd);
-			pd = parent;
-			spin_lock(&pd->d_lock);
-		}
-		spin_unlock(&pd->d_lock);
+		struct dentry *pd = find_disconnected_root(target_dir);
  
 		if (!IS_ROOT(pd)) {
 			/* must have found a connected parent - great */
...	...	@@ -70,6 +70,27 @@
70	70	return NULL;
71	71	}
72	72
	73	+/*
	74	+ * Find root of a disconnected subtree and return a reference to it.
	75	+ */
	76	+static struct dentry *
	77	+find_disconnected_root(struct dentry *dentry)
	78	+{
	79	+ dget(dentry);
	80	+ spin_lock(&dentry->d_lock);
	81	+ while (!IS_ROOT(dentry) &&
	82	+ (dentry->d_parent->d_flags & DCACHE_DISCONNECTED)) {
	83	+ struct dentry *parent = dentry->d_parent;
	84	+ dget(parent);
	85	+ spin_unlock(&dentry->d_lock);
	86	+ dput(dentry);
	87	+ dentry = parent;
	88	+ spin_lock(&dentry->d_lock);
	89	+ }
	90	+ spin_unlock(&dentry->d_lock);
	91	+ return dentry;
	92	+}
	93	+
73	94	/**
74	95	* find_exported_dentry - helper routine to implement export_operations->decode_fh
75	96	* @sb: The &super_block identifying the filesystem
76	97
...	...	@@ -164,23 +185,9 @@
164	185	* the noprogress counter. If we go through the loop 10 times (2 is
165	186	* probably enough) without getting anywhere, we just give up
166	187	*/
167		- noprogress= 0;
	188	+ noprogress = 0;
168	189	while (target_dir->d_flags & DCACHE_DISCONNECTED && noprogress++ < 10) {
169		- struct dentry *pd = target_dir;
170		-
171		- dget(pd);
172		- spin_lock(&pd->d_lock);
173		- while (!IS_ROOT(pd) &&
174		- (pd->d_parent->d_flags&DCACHE_DISCONNECTED)) {
175		- struct dentry *parent = pd->d_parent;
176		-
177		- dget(parent);
178		- spin_unlock(&pd->d_lock);
179		- dput(pd);
180		- pd = parent;
181		- spin_lock(&pd->d_lock);
182		- }
183		- spin_unlock(&pd->d_lock);
	190	+ struct dentry *pd = find_disconnected_root(target_dir);
184	191
185	192	if (!IS_ROOT(pd)) {
186	193	/* must have found a connected parent - great */