diff options
| -rw-r--r-- | fs/inode.c | 45 | ||||
| -rw-r--r-- | include/linux/fs.h | 3 |
2 files changed, 42 insertions, 6 deletions
diff --git a/fs/inode.c b/fs/inode.c index 96364fae0844..e57f1724db3e 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 c9bf3746a9fb..0f53e0124941 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); |