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authorSrinivas Eeda <srinivas.eeda@oracle.com>2009-06-03 17:02:55 -0700
committerJoel Becker <joel.becker@oracle.com>2009-06-03 19:14:31 -0700
commit83273932fbefb6ceef9c0b82ac4d23900728f4d9 (patch)
tree7ece8471af3d2a22543542e990369aca47aa3d25 /fs/ocfs2/dlmglue.c
parentedd45c08499a3e9d4c25431cd2b6a9ce5f692c92 (diff)
downloadop-kernel-dev-83273932fbefb6ceef9c0b82ac4d23900728f4d9.zip
op-kernel-dev-83273932fbefb6ceef9c0b82ac4d23900728f4d9.tar.gz
ocfs2: timer to queue scan of all orphan slots
When a dentry is unlinked, the unlinking node takes an EX on the dentry lock before moving the dentry to the orphan directory. Other nodes that have this dentry in cache have a PR on the same dentry lock. When the EX is requested, the other nodes flag the corresponding inode as MAYBE_ORPHANED during downconvert. The inode is finally deleted when the last node to iput the inode sees that i_nlink==0 and the MAYBE_ORPHANED flag is set. A problem arises if a node is forced to free dentry locks because of memory pressure. If this happens, the node will no longer get downconvert notifications for the dentries that have been unlinked on another node. If it also happens that node is actively using the corresponding inode and happens to be the one performing the last iput on that inode, it will fail to delete the inode as it will not have the MAYBE_ORPHANED flag set. This patch fixes this shortcoming by introducing a periodic scan of the orphan directories to delete such inodes. Care has been taken to distribute the workload across the cluster so that no one node has to perform the task all the time. Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
Diffstat (limited to 'fs/ocfs2/dlmglue.c')
-rw-r--r--fs/ocfs2/dlmglue.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index e15fc7d..6cdeaa7 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -248,6 +248,10 @@ static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
.flags = 0,
};
+static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
+ .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
+};
+
static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
.get_osb = ocfs2_get_dentry_osb,
.post_unlock = ocfs2_dentry_post_unlock,
@@ -637,6 +641,19 @@ static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
&ocfs2_nfs_sync_lops, osb);
}
+static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
+ struct ocfs2_super *osb)
+{
+ struct ocfs2_orphan_scan_lvb *lvb;
+
+ ocfs2_lock_res_init_once(res);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name);
+ ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN,
+ &ocfs2_orphan_scan_lops, osb);
+ lvb = ocfs2_dlm_lvb(&res->l_lksb);
+ lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
+}
+
void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
struct ocfs2_file_private *fp)
{
@@ -2352,6 +2369,37 @@ void ocfs2_inode_unlock(struct inode *inode,
mlog_exit_void();
}
+int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno, int ex)
+{
+ struct ocfs2_lock_res *lockres;
+ struct ocfs2_orphan_scan_lvb *lvb;
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ int status = 0;
+
+ lockres = &osb->osb_orphan_scan.os_lockres;
+ status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+ if (status < 0)
+ return status;
+
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+ if (lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
+ *seqno = be32_to_cpu(lvb->lvb_os_seqno);
+ return status;
+}
+
+void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno, int ex)
+{
+ struct ocfs2_lock_res *lockres;
+ struct ocfs2_orphan_scan_lvb *lvb;
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+
+ lockres = &osb->osb_orphan_scan.os_lockres;
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+ lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
+ lvb->lvb_os_seqno = cpu_to_be32(seqno);
+ ocfs2_cluster_unlock(osb, lockres, level);
+}
+
int ocfs2_super_lock(struct ocfs2_super *osb,
int ex)
{
@@ -2842,6 +2890,7 @@ local:
ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
+ ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
osb->cconn = conn;
@@ -2878,6 +2927,7 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
ocfs2_lock_res_free(&osb->osb_super_lockres);
ocfs2_lock_res_free(&osb->osb_rename_lockres);
ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
+ ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
osb->cconn = NULL;
@@ -3061,6 +3111,7 @@ static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
+ ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres);
}
int ocfs2_drop_inode_locks(struct inode *inode)
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