From 24c19ef40474c3930597f31ae233dc06319bd881 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Fri, 22 Sep 2006 17:28:19 -0700 Subject: ocfs2: Remove i_generation from inode lock names OCFS2 puts inode meta data in the "lock value block" provided by the DLM. Typically, i_generation is encoded in the lock name so that a deleted inode on and a new one in the same block don't share the same lvb. Unfortunately, that scheme means that the read in ocfs2_read_locked_inode() is potentially thrown away as soon as the meta data lock is taken - we cannot encode the lock name without first knowing i_generation, which requires a disk read. This patch encodes i_generation in the inode meta data lvb, and removes the value from the inode meta data lock name. This way, the read can be covered by a lock, and at the same time we can distinguish between an up to date and a stale LVB. This will help cold-cache stat(2) performance in particular. Since this patch changes the protocol version, we take the opportunity to do a minor re-organization of two of the LVB fields. Signed-off-by: Mark Fasheh --- fs/ocfs2/dlmglue.c | 42 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 6 deletions(-) (limited to 'fs/ocfs2/dlmglue.c') diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 6cd84dffbbf4..ecb3cba22814 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -320,6 +320,7 @@ void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res) void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, enum ocfs2_lock_type type, + unsigned int generation, struct inode *inode) { struct ocfs2_lock_res_ops *ops; @@ -341,7 +342,7 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, }; ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno, - inode->i_generation, res->l_name); + generation, res->l_name); ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode); } @@ -1173,17 +1174,19 @@ static void ocfs2_cluster_unlock(struct ocfs2_super *osb, int ocfs2_create_new_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, - int ex) + int ex, + int local) { int level = ex ? LKM_EXMODE : LKM_PRMODE; unsigned long flags; + int lkm_flags = local ? LKM_LOCAL : 0; spin_lock_irqsave(&lockres->l_lock, flags); BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); lockres_or_flags(lockres, OCFS2_LOCK_LOCAL); spin_unlock_irqrestore(&lockres->l_lock, flags); - return ocfs2_lock_create(osb, lockres, level, LKM_LOCAL); + return ocfs2_lock_create(osb, lockres, level, lkm_flags); } /* Grants us an EX lock on the data and metadata resources, skipping @@ -1212,19 +1215,23 @@ int ocfs2_create_new_inode_locks(struct inode *inode) * on a resource which has an invalid one -- we'll set it * valid when we release the EX. */ - ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1); + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1); if (ret) { mlog_errno(ret); goto bail; } - ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1); + /* + * We don't want to use LKM_LOCAL on a meta data lock as they + * don't use a generation in their lock names. + */ + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0); if (ret) { mlog_errno(ret); goto bail; } - ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1); + ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1); if (ret) { mlog_errno(ret); goto bail; @@ -1413,6 +1420,16 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode) lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb; + /* + * Invalidate the LVB of a deleted inode - this way other + * nodes are forced to go to disk and discover the new inode + * status. + */ + if (oi->ip_flags & OCFS2_INODE_DELETED) { + lvb->lvb_version = 0; + goto out; + } + lvb->lvb_version = OCFS2_LVB_VERSION; lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); @@ -1429,6 +1446,7 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode) lvb->lvb_iattr = cpu_to_be32(oi->ip_attr); lvb->lvb_igeneration = cpu_to_be32(inode->i_generation); +out: mlog_meta_lvb(0, lockres); mlog_exit_void(); @@ -1727,6 +1745,18 @@ int ocfs2_meta_lock_full(struct inode *inode, wait_event(osb->recovery_event, ocfs2_node_map_is_empty(osb, &osb->recovery_map)); + /* + * We only see this flag if we're being called from + * ocfs2_read_locked_inode(). It means we're locking an inode + * which hasn't been populated yet, so clear the refresh flag + * and let the caller handle it. + */ + if (inode->i_state & I_NEW) { + status = 0; + ocfs2_complete_lock_res_refresh(lockres, 0); + goto bail; + } + /* This is fun. The caller may want a bh back, or it may * not. ocfs2_meta_lock_update definitely wants one in, but * may or may not read one, depending on what's in the -- cgit v1.2.2