[PATCH] ext3: move lock_kernel() down into the JBD layer.

This is the start of the ext3 scalability rework.  It basically comes in two
halves:

- ext3 BKL/lock_super removal and scalable inode/block allocators

- JBD locking rework.

The ext3 scalability work was completed a couple of months ago.

The JBD rework has been stable for a couple of weeks now.  My gut feeling is
that there should be one, maybe two bugs left in it, but no problems have
been discovered...


Performance-wise, throughput is increased by up to 2x on dual CPU.  10x on
16-way has been measured.  Given that current ext3 is able to chew two whole
CPUs spinning on locks on a 4-way, that wasn't especially suprising.

These patches were prepared by Alex Tomas <bzzz@tmi.comex.ru> and myself.


First patch: ext3 lock_kernel() removal.

The only reason why ext3 takes lock_kernel() is because it is requires by the
JBD API.

The patch removes the lock_kernels() from ext3 and pushes them down into JBD
itself.

1 files changed, 0 insertions, 2 deletions

diff --git a/fs/ext3/xattr.c b/fs/ext3/xattr.c
index cd8cb24a344158..5ca5e3086e0670 100644
--- a/fs/ext3/xattr.c
+++ b/fs/ext3/xattr.c
@@ -849,7 +849,6 @@ ext3_xattr_set(struct inode *inode, int name_index, const char *name,
 	handle_t *handle;
 	int error, error2;
 
-	lock_kernel();
 	handle = ext3_journal_start(inode, EXT3_XATTR_TRANS_BLOCKS);
 	if (IS_ERR(handle))
 		error = PTR_ERR(handle);
@@ -857,7 +856,6 @@ ext3_xattr_set(struct inode *inode, int name_index, const char *name,
 		error = ext3_xattr_set_handle(handle, inode, name_index, name,
 					      value, value_len, flags);
 	error2 = ext3_journal_stop(handle);
-	unlock_kernel();
 
 	return error ? error : error2;
 }