fs: dlm: switch lkb_sbflags to atomic ops

This patch moves lkb_sbflags handling to atomic bits ops. This should
prepare for a possible manipulating of lkb_sbflags flags at the same
time by concurrent execution.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index e2925f554bc778d02446485cd84c3e8a1f4ea767..986a9d7b1f33280a48359c73836ccae2aa4f5009 100644 (file)
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -235,7 +235,7 @@ struct dlm_lkb {
        uint32_t                lkb_id;         /* our lock ID */
        uint32_t                lkb_remid;      /* lock ID on remote partner */
        uint32_t                lkb_exflags;    /* external flags from caller */
-       uint32_t                lkb_sbflags;    /* lksb flags */
+       unsigned long           lkb_sbflags;    /* lksb flags */
        unsigned long           lkb_dflags;     /* distributed flags */
        unsigned long           lkb_iflags;     /* internal flags */
        uint32_t                lkb_lvbseq;     /* lvb sequence number */
@@ -760,6 +760,26 @@ static inline uint32_t dlm_dflags_val(const struct dlm_lkb *lkb)
                             __DLM_DFL_MAX_BIT);
 }
 
+/* coming from UAPI header
+ *
+ * TODO:
+ * Move this to UAPI header and let other values point to them and use BIT()
+ */
+#define DLM_SBF_DEMOTED_BIT    0
+#define __DLM_SBF_MIN_BIT      DLM_SBF_DEMOTED_BIT
+#define DLM_SBF_VALNOTVALID_BIT        1
+#define DLM_SBF_ALTMODE_BIT    2
+#define __DLM_SBF_MAX_BIT      DLM_SBF_ALTMODE_BIT
+
+static inline uint32_t dlm_sbflags_val(const struct dlm_lkb *lkb)
+{
+       /* be sure the next person updates this */
+       BUILD_BUG_ON(BIT(__DLM_SBF_MAX_BIT) != DLM_SBF_ALTMODE);
+
+       return dlm_flags_val(&lkb->lkb_sbflags, __DLM_SBF_MIN_BIT,
+                            __DLM_SBF_MAX_BIT);
+}
+
 static inline void dlm_set_flags_val(unsigned long *addr, uint32_t val,
                                     uint32_t min, uint32_t max)
 {
@@ -779,6 +799,12 @@ static inline void dlm_set_dflags_val(struct dlm_lkb *lkb, uint32_t val)
                          __DLM_DFL_MAX_BIT);
 }
 
+static inline void dlm_set_sbflags_val(struct dlm_lkb *lkb, uint32_t val)
+{
+       dlm_set_flags_val(&lkb->lkb_sbflags, val, __DLM_SBF_MIN_BIT,
+                         __DLM_SBF_MAX_BIT);
+}
+
 int dlm_plock_init(void);
 void dlm_plock_exit(void);
 

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 507a03fe22798842898818926f272f4f22179268..1582c8b1404c9c37a4e68510dfe68e6c60f03747 100644 (file)
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -228,12 +228,12 @@ static inline int force_blocking_asts(struct dlm_lkb *lkb)
 
 static inline int is_demoted(struct dlm_lkb *lkb)
 {
-       return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
+       return test_bit(DLM_SBF_DEMOTED_BIT, &lkb->lkb_sbflags);
 }
 
 static inline int is_altmode(struct dlm_lkb *lkb)
 {
-       return (lkb->lkb_sbflags & DLM_SBF_ALTMODE);
+       return test_bit(DLM_SBF_ALTMODE_BIT, &lkb->lkb_sbflags);
 }
 
 static inline int is_granted(struct dlm_lkb *lkb)
@@ -298,7 +298,7 @@ static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
            test_and_clear_bit(DLM_IFL_DEADLOCK_CANCEL_BIT, &lkb->lkb_iflags))
                rv = -EDEADLK;
 
-       dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, lkb->lkb_sbflags);
+       dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, dlm_sbflags_val(lkb));
 }
 
 static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb)
@@ -1770,7 +1770,7 @@ static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
        }
 
        if (rsb_flag(r, RSB_VALNOTVALID))
-               lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
+               set_bit(DLM_SBF_VALNOTVALID_BIT, &lkb->lkb_sbflags);
 }
 
 static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
@@ -2242,7 +2242,7 @@ static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
            conversion_deadlock_detect(r, lkb)) {
                if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) {
                        lkb->lkb_grmode = DLM_LOCK_NL;
-                       lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
+                       set_bit(DLM_SBF_DEMOTED_BIT, &lkb->lkb_sbflags);
                } else if (err) {
                        *err = -EDEADLK;
                } else {
@@ -2269,7 +2269,7 @@ static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
                lkb->lkb_rqmode = alt;
                rv = _can_be_granted(r, lkb, now, 0);
                if (rv)
-                       lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
+                       set_bit(DLM_SBF_ALTMODE_BIT, &lkb->lkb_sbflags);
                else
                        lkb->lkb_rqmode = rqmode;
        }
@@ -2685,7 +2685,7 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
        }
 
        lkb->lkb_exflags = args->flags;
-       lkb->lkb_sbflags = 0;
+       dlm_set_sbflags_val(lkb, 0);
        lkb->lkb_astfn = args->astfn;
        lkb->lkb_astparam = args->astparam;
        lkb->lkb_bastfn = args->bastfn;
@@ -2836,7 +2836,7 @@ static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
  out_ok:
        /* an overlapping op shouldn't blow away exflags from other op */
        lkb->lkb_exflags |= args->flags;
-       lkb->lkb_sbflags = 0;
+       dlm_set_sbflags_val(lkb, 0);
        lkb->lkb_astparam = args->astparam;
        rv = 0;
  out:
@@ -3408,7 +3408,7 @@ static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
        ms->m_lkid     = cpu_to_le32(lkb->lkb_id);
        ms->m_remid    = cpu_to_le32(lkb->lkb_remid);
        ms->m_exflags  = cpu_to_le32(lkb->lkb_exflags);
-       ms->m_sbflags  = cpu_to_le32(lkb->lkb_sbflags);
+       ms->m_sbflags  = cpu_to_le32(dlm_sbflags_val(lkb));
        ms->m_flags    = cpu_to_le32(dlm_dflags_val(lkb));
        ms->m_lvbseq   = cpu_to_le32(lkb->lkb_lvbseq);
        ms->m_status   = cpu_to_le32(lkb->lkb_status);
@@ -3673,7 +3673,7 @@ static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
 static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
 {
        lkb->lkb_exflags = le32_to_cpu(ms->m_exflags);
-       lkb->lkb_sbflags = le32_to_cpu(ms->m_sbflags);
+       dlm_set_sbflags_val(lkb, le32_to_cpu(ms->m_sbflags));
        dlm_set_dflags_val(lkb, le32_to_cpu(ms->m_flags));
 }
 
@@ -3683,7 +3683,7 @@ static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms,
        if (local)
                return;
 
-       lkb->lkb_sbflags = le32_to_cpu(ms->m_sbflags);
+       dlm_set_sbflags_val(lkb, le32_to_cpu(ms->m_sbflags));
        dlm_set_dflags_val(lkb, le32_to_cpu(ms->m_flags));
 }