Mark the occasion by open-coding the atomic_dec_and_lock from inode
refcounting, and replace it with an open coded equivalent. This is in
preparation for breaking the inode_lock into multiple locks (dec_and_lock can
only handle one lock at a time).
Signed-off-by: Nick Piggin <npiggin@xxxxxxxxx>
---
fs/inode.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c 2010-10-21 23:49:56.000000000 +1100
+++ linux-2.6/fs/inode.c 2010-10-21 23:50:49.000000000 +1100
@@ -26,6 +26,16 @@
#include <linux/posix_acl.h>
/*
+ * Icache locking
+ *
+ * Usage:
+ * inode_lock protects:
+ * everything
+ *
+ * Ordering:
+ * inode_lock
+ */
+/*
* This is needed for the following functions:
* - inode_has_buffers
* - invalidate_inode_buffers
@@ -1259,8 +1269,14 @@ void iput(struct inode *inode)
if (inode) {
BUG_ON(inode->i_state & I_CLEAR);
- if (atomic_dec_and_lock(&inode->i_count, &inode_lock))
+ /* open-code atomic_dec_and_lock */
+ if (atomic_add_unless(&inode->i_count, -1, 1))
+ return;
+ spin_lock(&inode_lock);
+ if (atomic_dec_and_test(&inode->i_count))
iput_final(inode);
+ else
+ spin_unlock(&inode_lock);
}
}
EXPORT_SYMBOL(iput);
--
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