I thought I would ask for opinions on this because it can come in handy
to avoid locking to use an iget() rather than igrab() if we do lazy LRU
(like the dcache), then iget() just increments the refcount and doesn't
require any more locking.
I thought it might be useful anyway to avoid igrab misuse by
filesystems? So after this patch we should use igrab for when we don't
already have the inode pinned. Introduce iget for when we do.
The interfaces don't change, but __must_check will prompt filesystems to
use the correct API.
Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c
+++ linux-2.6/fs/inode.c
@@ -296,6 +296,15 @@ void __iget(struct inode *inode)
inodes_stat.nr_unused--;
}
+void iget(struct inode *inode)
+{
+ spin_lock(&inode_lock);
+ __iget(inode);
+ spin_unlock(&inode_lock);
+ BUG_ON(inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE));
+}
+EXPORT_SYMBOL(iget);
+
/**
* clear_inode - clear an inode
* @inode: inode to clear
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h
+++ linux-2.6/include/linux/fs.h
@@ -2146,7 +2146,7 @@ extern int inode_init_always(struct supe
extern void inode_init_once(struct inode *);
extern void inode_add_to_lists(struct super_block *, struct inode *);
extern void iput(struct inode *);
-extern struct inode * igrab(struct inode *);
+extern struct inode * __must_check igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);
extern void generic_delete_inode(struct inode *inode);
@@ -2166,6 +2166,7 @@ extern int insert_inode_locked4(struct i
extern int insert_inode_locked(struct inode *);
extern void unlock_new_inode(struct inode *);
+extern void iget(struct inode * inode);
extern void __iget(struct inode * inode);
extern void iget_failed(struct inode *);
extern void clear_inode(struct inode *);
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
