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authorAlexander Aring <aahringo@redhat.com>2021-11-30 14:47:16 -0500
committerDavid Teigland <teigland@redhat.com>2021-12-07 12:42:26 -0600
commit21d9ac1a5376d949199398848006f6b14649f533 (patch)
tree673a07f065a27bd8d473c69cc915a586c970f257 /fs/dlm
parentbcbfea41e1f9d516faed1faf0f2d390c000bf0d9 (diff)
fs: dlm: use event based wait for pending remove
This patch will use an event based waitqueue to wait for a possible clash with the ls_remove_name field of dlm_ls instead of doing busy waiting. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
Diffstat (limited to 'fs/dlm')
-rw-r--r--fs/dlm/dlm_internal.h1
-rw-r--r--fs/dlm/lock.c19
-rw-r--r--fs/dlm/lockspace.c1
3 files changed, 14 insertions, 7 deletions
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 019931804af9..74a9590a4dd5 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -576,6 +576,7 @@ struct dlm_ls {
struct list_head ls_new_rsb; /* new rsb structs */
spinlock_t ls_remove_spin;
+ wait_queue_head_t ls_remove_wait;
char ls_remove_name[DLM_RESNAME_MAXLEN+1];
char *ls_remove_names[DLM_REMOVE_NAMES_MAX];
int ls_remove_len;
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 54705d367076..bdb51d209ba2 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -1626,21 +1626,24 @@ static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms)
}
/* If there's an rsb for the same resource being removed, ensure
- that the remove message is sent before the new lookup message.
- It should be rare to need a delay here, but if not, then it may
- be worthwhile to add a proper wait mechanism rather than a delay. */
+ * that the remove message is sent before the new lookup message.
+ */
+
+#define DLM_WAIT_PENDING_COND(ls, r) \
+ (ls->ls_remove_len && \
+ !rsb_cmp(r, ls->ls_remove_name, \
+ ls->ls_remove_len))
static void wait_pending_remove(struct dlm_rsb *r)
{
struct dlm_ls *ls = r->res_ls;
restart:
spin_lock(&ls->ls_remove_spin);
- if (ls->ls_remove_len &&
- !rsb_cmp(r, ls->ls_remove_name, ls->ls_remove_len)) {
+ if (DLM_WAIT_PENDING_COND(ls, r)) {
log_debug(ls, "delay lookup for remove dir %d %s",
- r->res_dir_nodeid, r->res_name);
+ r->res_dir_nodeid, r->res_name);
spin_unlock(&ls->ls_remove_spin);
- msleep(1);
+ wait_event(ls->ls_remove_wait, !DLM_WAIT_PENDING_COND(ls, r));
goto restart;
}
spin_unlock(&ls->ls_remove_spin);
@@ -1792,6 +1795,7 @@ static void shrink_bucket(struct dlm_ls *ls, int b)
memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
spin_unlock(&ls->ls_remove_spin);
spin_unlock(&ls->ls_rsbtbl[b].lock);
+ wake_up(&ls->ls_remove_wait);
send_remove(r);
@@ -4075,6 +4079,7 @@ static void send_repeat_remove(struct dlm_ls *ls, char *ms_name, int len)
memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
spin_unlock(&ls->ls_remove_spin);
spin_unlock(&ls->ls_rsbtbl[b].lock);
+ wake_up(&ls->ls_remove_wait);
rv = _create_message(ls, sizeof(struct dlm_message) + len,
dir_nodeid, DLM_MSG_REMOVE, &ms, &mh);
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 2e51bd2bdacc..31384e7d6f90 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -512,6 +512,7 @@ static int new_lockspace(const char *name, const char *cluster,
}
spin_lock_init(&ls->ls_remove_spin);
+ init_waitqueue_head(&ls->ls_remove_wait);
for (i = 0; i < DLM_REMOVE_NAMES_MAX; i++) {
ls->ls_remove_names[i] = kzalloc(DLM_RESNAME_MAXLEN+1,