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-rw-r--r--fs/inode.c45
-rw-r--r--include/linux/fs.h3
2 files changed, 42 insertions, 6 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 96364fae084..e57f1724db3 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -757,6 +757,7 @@ EXPORT_SYMBOL(igrab);
* @head: the head of the list to search
* @test: callback used for comparisons between inodes
* @data: opaque data pointer to pass to @test
+ * @wait: if true wait for the inode to be unlocked, if false do not
*
* ifind() searches for the inode specified by @data in the inode
* cache. This is a generalized version of ifind_fast() for file systems where
@@ -771,7 +772,7 @@ EXPORT_SYMBOL(igrab);
*/
static inline struct inode *ifind(struct super_block *sb,
struct hlist_head *head, int (*test)(struct inode *, void *),
- void *data)
+ void *data, const int wait)
{
struct inode *inode;
@@ -780,7 +781,8 @@ static inline struct inode *ifind(struct super_block *sb,
if (inode) {
__iget(inode);
spin_unlock(&inode_lock);
- wait_on_inode(inode);
+ if (likely(wait))
+ wait_on_inode(inode);
return inode;
}
spin_unlock(&inode_lock);
@@ -820,7 +822,7 @@ static inline struct inode *ifind_fast(struct super_block *sb,
}
/**
- * ilookup5 - search for an inode in the inode cache
+ * ilookup5_nowait - search for an inode in the inode cache
* @sb: super block of file system to search
* @hashval: hash value (usually inode number) to search for
* @test: callback used for comparisons between inodes
@@ -832,7 +834,38 @@ static inline struct inode *ifind_fast(struct super_block *sb,
* identification of an inode.
*
* If the inode is in the cache, the inode is returned with an incremented
- * reference count.
+ * reference count. Note, the inode lock is not waited upon so you have to be
+ * very careful what you do with the returned inode. You probably should be
+ * using ilookup5() instead.
+ *
+ * Otherwise NULL is returned.
+ *
+ * Note, @test is called with the inode_lock held, so can't sleep.
+ */
+struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
+ int (*test)(struct inode *, void *), void *data)
+{
+ struct hlist_head *head = inode_hashtable + hash(sb, hashval);
+
+ return ifind(sb, head, test, data, 0);
+}
+
+EXPORT_SYMBOL(ilookup5_nowait);
+
+/**
+ * ilookup5 - search for an inode in the inode cache
+ * @sb: super block of file system to search
+ * @hashval: hash value (usually inode number) to search for
+ * @test: callback used for comparisons between inodes
+ * @data: opaque data pointer to pass to @test
+ *
+ * ilookup5() uses ifind() to search for the inode specified by @hashval and
+ * @data in the inode cache. This is a generalized version of ilookup() for
+ * file systems where the inode number is not sufficient for unique
+ * identification of an inode.
+ *
+ * If the inode is in the cache, the inode lock is waited upon and the inode is
+ * returned with an incremented reference count.
*
* Otherwise NULL is returned.
*
@@ -843,7 +876,7 @@ struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
{
struct hlist_head *head = inode_hashtable + hash(sb, hashval);
- return ifind(sb, head, test, data);
+ return ifind(sb, head, test, data, 1);
}
EXPORT_SYMBOL(ilookup5);
@@ -900,7 +933,7 @@ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
struct hlist_head *head = inode_hashtable + hash(sb, hashval);
struct inode *inode;
- inode = ifind(sb, head, test, data);
+ inode = ifind(sb, head, test, data, 1);
if (inode)
return inode;
/*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c9bf3746a9f..0f53e012494 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1441,6 +1441,9 @@ extern int inode_needs_sync(struct inode *inode);
extern void generic_delete_inode(struct inode *inode);
extern void generic_drop_inode(struct inode *inode);
+extern struct inode *ilookup5_nowait(struct super_block *sb,
+ unsigned long hashval, int (*test)(struct inode *, void *),
+ void *data);
extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
int (*test)(struct inode *, void *), void *data);
extern struct inode *ilookup(struct super_block *sb, unsigned long ino);