From 6802e3400ff4549525930ee744030c36fce9cc73 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Wed, 21 May 2008 17:03:22 +0100 Subject: [GFS2] Clean up the glock core This patch implements a number of cleanups to the core of the GFS2 glock code. As a result a lot of code is removed. It looks like a really big change, but actually a large part of this patch is either removing or moving existing code. There are some new bits too though, such as the new run_queue() function which is considerably streamlined. Highlights of this patch include: o Fixes a cluster coherency bug during SH -> EX lock conversions o Removes the "glmutex" code in favour of a single bit lock o Removes the ->go_xmote_bh() for inodes since it was duplicating ->go_lock() o We now only use the ->lm_lock() function for both locks and unlocks (i.e. unlock is a lock with target mode LM_ST_UNLOCKED) o The fast path is considerably shortly, giving performance gains especially with lock_nolock o The glock_workqueue is now used for all the callbacks from the DLM which allows us to simplify the lock_dlm module (see following patch) o The way is now open to make further changes such as eliminating the two threads (gfs2_glockd and gfs2_scand) in favour of a more efficient scheme. This patch has undergone extensive testing with various test suites so it should be pretty stable by now. Signed-off-by: Steven Whitehouse Cc: Bob Peterson --- fs/gfs2/ops_address.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) (limited to 'fs/gfs2/ops_address.c') diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c index f55394e57cb2..2b556dd034bb 100644 --- a/fs/gfs2/ops_address.c +++ b/fs/gfs2/ops_address.c @@ -507,26 +507,23 @@ static int __gfs2_readpage(void *file, struct page *page) static int gfs2_readpage(struct file *file, struct page *page) { struct gfs2_inode *ip = GFS2_I(page->mapping->host); - struct gfs2_holder *gh; + struct gfs2_holder gh; int error; - gh = gfs2_glock_is_locked_by_me(ip->i_gl); - if (!gh) { - gh = kmalloc(sizeof(struct gfs2_holder), GFP_NOFS); - if (!gh) - return -ENOBUFS; - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, gh); + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh); + error = gfs2_glock_nq_atime(&gh); + if (unlikely(error)) { unlock_page(page); - error = gfs2_glock_nq_atime(gh); - if (likely(error != 0)) - goto out; - return AOP_TRUNCATED_PAGE; + goto out; } error = __gfs2_readpage(file, page); - gfs2_glock_dq(gh); + gfs2_glock_dq(&gh); out: - gfs2_holder_uninit(gh); - kfree(gh); + gfs2_holder_uninit(&gh); + if (error == GLR_TRYFAILED) { + yield(); + return AOP_TRUNCATED_PAGE; + } return error; } -- cgit v1.2.3