[PATCH v2 1/2] ocfs2: add trimfs dlm lock resource

[Gang He]

Introduce a new dlm lock resource, which will be used to
communicate during fstrim a ocfs2 device from cluster nodes.

Signed-off-by: Gang He <ghe@xxxxxxxx>
---
 fs/ocfs2/dlmglue.c      | 86 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ocfs2/dlmglue.h      | 29 +++++++++++++++++
 fs/ocfs2/ocfs2.h        |  1 +
 fs/ocfs2/ocfs2_lockid.h |  5 +++
 4 files changed, 121 insertions(+)

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 4689940..5615747 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -259,6 +259,10 @@ struct ocfs2_lock_res_ops {
 	.flags		= 0,
 };
 
+static struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = {
+	.flags		= LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
+};
+
 static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
 	.flags		= LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
 };
@@ -676,6 +680,24 @@ static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
 				   &ocfs2_nfs_sync_lops, osb);
 }
 
+void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb)
+{
+	struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
+
+	ocfs2_lock_res_init_once(lockres);
+	ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name);
+	ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS,
+				   &ocfs2_trim_fs_lops, osb);
+}
+
+void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb)
+{
+	struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
+
+	ocfs2_simple_drop_lockres(osb, lockres);
+	ocfs2_lock_res_free(lockres);
+}
+
 static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
 					    struct ocfs2_super *osb)
 {
@@ -2745,6 +2767,70 @@ void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
 				     ex ? LKM_EXMODE : LKM_PRMODE);
 }
 
+int ocfs2_trim_fs_lock(struct ocfs2_super *osb,
+		       struct ocfs2_trim_fs_info *info, int trylock)
+{
+	int status;
+	struct ocfs2_trim_fs_lvb *lvb;
+	struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
+
+	if (info)
+		info->tf_valid = 0;
+
+	if (ocfs2_is_hard_readonly(osb))
+		return -EROFS;
+
+	if (ocfs2_mount_local(osb))
+		return 0;
+
+	status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX,
+				    trylock ? DLM_LKF_NOQUEUE : 0, 0);
+	if (status < 0) {
+		if (status != -EAGAIN)
+			mlog_errno(status);
+		return status;
+	}
+
+	if (info) {
+		lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+		if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
+		    lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) {
+			info->tf_valid = 1;
+			info->tf_success = lvb->lvb_success;
+			info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum);
+			info->tf_start = be64_to_cpu(lvb->lvb_start);
+			info->tf_len = be64_to_cpu(lvb->lvb_len);
+			info->tf_minlen = be64_to_cpu(lvb->lvb_minlen);
+			info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen);
+		}
+	}
+
+	return status;
+}
+
+void ocfs2_trim_fs_unlock(struct ocfs2_super *osb,
+			  struct ocfs2_trim_fs_info *info)
+{
+	struct ocfs2_trim_fs_lvb *lvb;
+	struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
+
+	if (ocfs2_mount_local(osb))
+		return;
+
+	if (info) {
+		lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+		lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION;
+		lvb->lvb_success = info->tf_success;
+		lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum);
+		lvb->lvb_start = cpu_to_be64(info->tf_start);
+		lvb->lvb_len = cpu_to_be64(info->tf_len);
+		lvb->lvb_minlen = cpu_to_be64(info->tf_minlen);
+		lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen);
+	}
+
+	ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
+}
+
 int ocfs2_dentry_lock(struct dentry *dentry, int ex)
 {
 	int ret;
diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h
index a7fc18b..2253688 100644
--- a/fs/ocfs2/dlmglue.h
+++ b/fs/ocfs2/dlmglue.h
@@ -70,6 +70,29 @@ struct ocfs2_orphan_scan_lvb {
 	__be32	lvb_os_seqno;
 };
 
+#define OCFS2_TRIMFS_LVB_VERSION 1
+
+struct ocfs2_trim_fs_lvb {
+	__u8	lvb_version;
+	__u8	lvb_success;
+	__u8	lvb_reserved[2];
+	__be32	lvb_nodenum;
+	__be64	lvb_start;
+	__be64	lvb_len;
+	__be64	lvb_minlen;
+	__be64	lvb_trimlen;
+};
+
+struct ocfs2_trim_fs_info {
+	u8	tf_valid;	/* lvb is valid, or not */
+	u8	tf_success;	/* trim is successful, or not */
+	u32	tf_nodenum;	/* osb node number */
+	u64	tf_start;	/* trim start offset in clusters */
+	u64	tf_len;		/* trim end offset in clusters */
+	u64	tf_minlen;	/* trim minimum contiguous free clusters */
+	u64	tf_trimlen;	/* trimmed length in bytes */
+};
+
 struct ocfs2_lock_holder {
 	struct list_head oh_list;
 	struct pid *oh_owner_pid;
@@ -153,6 +176,12 @@ void ocfs2_super_unlock(struct ocfs2_super *osb,
 void ocfs2_rename_unlock(struct ocfs2_super *osb);
 int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex);
 void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex);
+void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb);
+void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb);
+int ocfs2_trim_fs_lock(struct ocfs2_super *osb,
+		       struct ocfs2_trim_fs_info *info, int trylock);
+void ocfs2_trim_fs_unlock(struct ocfs2_super *osb,
+			  struct ocfs2_trim_fs_info *info);
 int ocfs2_dentry_lock(struct dentry *dentry, int ex);
 void ocfs2_dentry_unlock(struct dentry *dentry, int ex);
 int ocfs2_file_lock(struct file *file, int ex, int trylock);
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 9a50f22..6867eef 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -404,6 +404,7 @@ struct ocfs2_super
 	struct ocfs2_lock_res osb_super_lockres;
 	struct ocfs2_lock_res osb_rename_lockres;
 	struct ocfs2_lock_res osb_nfs_sync_lockres;
+	struct ocfs2_lock_res osb_trim_fs_lockres;
 	struct ocfs2_dlm_debug *osb_dlm_debug;
 
 	struct dentry *osb_debug_root;
diff --git a/fs/ocfs2/ocfs2_lockid.h b/fs/ocfs2/ocfs2_lockid.h
index d277aab..7051b99 100644
--- a/fs/ocfs2/ocfs2_lockid.h
+++ b/fs/ocfs2/ocfs2_lockid.h
@@ -50,6 +50,7 @@ enum ocfs2_lock_type {
 	OCFS2_LOCK_TYPE_NFS_SYNC,
 	OCFS2_LOCK_TYPE_ORPHAN_SCAN,
 	OCFS2_LOCK_TYPE_REFCOUNT,
+	OCFS2_LOCK_TYPE_TRIM_FS,
 	OCFS2_NUM_LOCK_TYPES
 };
 
@@ -93,6 +94,9 @@ static inline char ocfs2_lock_type_char(enum ocfs2_lock_type type)
 		case OCFS2_LOCK_TYPE_REFCOUNT:
 			c = 'T';
 			break;
+		case OCFS2_LOCK_TYPE_TRIM_FS:
+			c = 'I';
+			break;
 		default:
 			c = '\0';
 	}
@@ -115,6 +119,7 @@ static inline char ocfs2_lock_type_char(enum ocfs2_lock_type type)
 	[OCFS2_LOCK_TYPE_NFS_SYNC] = "NFSSync",
 	[OCFS2_LOCK_TYPE_ORPHAN_SCAN] = "OrphanScan",
 	[OCFS2_LOCK_TYPE_REFCOUNT] = "Refcount",
+	[OCFS2_LOCK_TYPE_TRIM_FS] = "TrimFs",
 };
 
 static inline const char *ocfs2_lock_type_string(enum ocfs2_lock_type type)
-- 
1.8.5.6