[Cluster-devel] [PATCH v6.3-rc1 12/12] fs: dlm: switch ls_exflags to atomic ops

[Alexander Aring <aahringo@redhat.com>]

As other flag handling in dlm we switch ls_exflags to use atomic
operation to manipulate flags. This should prepare for a possible
manipulating of lkb_exflags flags at the same time by concurrent
execution.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 fs/dlm/dlm_internal.h | 23 ++++++++++++++++++++++-
 fs/dlm/lockspace.c    |  2 +-
 fs/dlm/rcom.c         |  6 +++---
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 986a9d7b1f33..48e9152555a8 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -548,7 +548,7 @@ struct dlm_ls {
 	dlm_lockspace_t		*ls_local_handle;
 	uint32_t		ls_global_id;	/* global unique lockspace ID */
 	uint32_t		ls_generation;
-	uint32_t		ls_exflags;
+	unsigned long		ls_exflags;
 	int			ls_lvblen;
 	atomic_t		ls_count;	/* refcount of processes in
 						   the dlm using this ls */
@@ -771,6 +771,11 @@ static inline uint32_t dlm_dflags_val(const struct dlm_lkb *lkb)
 #define DLM_SBF_ALTMODE_BIT	2
 #define __DLM_SBF_MAX_BIT	DLM_SBF_ALTMODE_BIT
 
+#define DLM_LSFL_TIMEWARN_BIT	1
+#define __DLM_LSFL_MIN_BIT	DLM_LSFL_TIMEWARN_BIT
+#define DLM_LSFL_NEWEXCL_BIT	3
+#define __DLM_LSFL_MAX_BIT	DLM_LSFL_NEWEXCL_BIT
+
 static inline uint32_t dlm_sbflags_val(const struct dlm_lkb *lkb)
 {
 	/* be sure the next person updates this */
@@ -780,6 +785,16 @@ static inline uint32_t dlm_sbflags_val(const struct dlm_lkb *lkb)
 			     __DLM_SBF_MAX_BIT);
 }
 
+static inline uint32_t dlm_ls_exflags_val(const struct dlm_ls *ls)
+{
+	/* be sure the next person updates this */
+	BUILD_BUG_ON(BIT(__DLM_LSFL_MIN_BIT) != DLM_LSFL_TIMEWARN ||
+		     BIT(__DLM_LSFL_MAX_BIT) != DLM_LSFL_NEWEXCL);
+
+	return dlm_flags_val(&ls->ls_exflags, __DLM_LSFL_MIN_BIT,
+			     __DLM_LSFL_MAX_BIT);
+}
+
 static inline void dlm_set_flags_val(unsigned long *addr, uint32_t val,
 				     uint32_t min, uint32_t max)
 {
@@ -805,6 +820,12 @@ static inline void dlm_set_sbflags_val(struct dlm_lkb *lkb, uint32_t val)
 			  __DLM_SBF_MAX_BIT);
 }
 
+static inline void dlm_set_ls_exflags(struct dlm_ls *ls, uint32_t val)
+{
+	dlm_set_flags_val(&ls->ls_exflags, val, __DLM_LSFL_MIN_BIT,
+			  __DLM_LSFL_MAX_BIT);
+}
+
 int dlm_plock_init(void);
 void dlm_plock_exit(void);
 
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 67261b7b1f0e..c47fcb292870 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -490,7 +490,7 @@ static int new_lockspace(const char *name, const char *cluster,
 	/* ls_exflags are forced to match among nodes, and we don't
 	 * need to require all nodes to have some flags set
 	 */
-	ls->ls_exflags = (flags & ~(DLM_LSFL_FS | DLM_LSFL_NEWEXCL));
+	dlm_set_ls_exflags(ls, flags & ~(DLM_LSFL_FS | DLM_LSFL_NEWEXCL));
 
 	size = READ_ONCE(dlm_config.ci_rsbtbl_size);
 	ls->ls_rsbtbl_size = size;
diff --git a/fs/dlm/rcom.c b/fs/dlm/rcom.c
index f4afdf892f78..5f0d7fe34b35 100644
--- a/fs/dlm/rcom.c
+++ b/fs/dlm/rcom.c
@@ -114,7 +114,7 @@ static void set_rcom_config(struct dlm_ls *ls, struct rcom_config *rf,
 			    uint32_t num_slots)
 {
 	rf->rf_lvblen = cpu_to_le32(ls->ls_lvblen);
-	rf->rf_lsflags = cpu_to_le32(ls->ls_exflags);
+	rf->rf_lsflags = cpu_to_le32(dlm_ls_exflags_val(ls));
 
 	rf->rf_our_slot = cpu_to_le16(ls->ls_slot);
 	rf->rf_num_slots = cpu_to_le16(num_slots);
@@ -133,9 +133,9 @@ static int check_rcom_config(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
 	}
 
 	if (le32_to_cpu(rf->rf_lvblen) != ls->ls_lvblen ||
-	    le32_to_cpu(rf->rf_lsflags) != ls->ls_exflags) {
+	    le32_to_cpu(rf->rf_lsflags) != dlm_ls_exflags_val(ls)) {
 		log_error(ls, "config mismatch: %d,%x nodeid %d: %d,%x",
-			  ls->ls_lvblen, ls->ls_exflags, nodeid,
+			  ls->ls_lvblen, dlm_ls_exflags_val(ls), nodeid,
 			  le32_to_cpu(rf->rf_lvblen),
 			  le32_to_cpu(rf->rf_lsflags));
 		return -EPROTO;
-- 
2.31.1