gfs2: Add GLF_PENDING_REPLY flag

Introduce a new GLF_PENDING_REPLY flag to indicate that a reply from DLM
is expected.  Include that flag in glock dumps to show more clearly
what's going on.  (When the GLF_PENDING_REPLY flag is set, the GLF_LOCK
flag will also be set but the GLF_LOCK flag alone isn't sufficient to
tell that we are waiting for a DLM reply.)

Signed-off-by: Andreas Gruenbacher <[email protected]>

Author: Andreas Gruenbacher

fs/gfs2/glock.c

@@ -807,6 +807,7 @@ __acquires(&gl->gl_lockref.lock)
 	}
 
 	if (ls->ls_ops->lm_lock) {
+		set_bit(GLF_PENDING_REPLY, &gl->gl_flags);
 		spin_unlock(&gl->gl_lockref.lock);
 		ret = ls->ls_ops->lm_lock(gl, target, lck_flags);
 		spin_lock(&gl->gl_lockref.lock);
@@ -825,6 +826,7 @@ __acquires(&gl->gl_lockref.lock)
 			/* The operation will be completed asynchronously. */
 			return;
 		}
+		clear_bit(GLF_PENDING_REPLY, &gl->gl_flags);
 	}
 
 	/* Complete the operation now. */
@@ -1923,6 +1925,7 @@ void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
 	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 
 	spin_lock(&gl->gl_lockref.lock);
+	clear_bit(GLF_PENDING_REPLY, &gl->gl_flags);
 	gl->gl_reply = ret;
 
 	if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {
@@ -2323,6 +2326,8 @@ static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
 		*p++ = 'f';
 	if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
 		*p++ = 'i';
+	if (test_bit(GLF_PENDING_REPLY, gflags))
+		*p++ = 'R';
 	if (test_bit(GLF_HAVE_REPLY, gflags))
 		*p++ = 'r';
 	if (test_bit(GLF_INITIAL, gflags))

fs/gfs2/incore.h

@@ -330,6 +330,7 @@ enum {
 	GLF_UNLOCKED			= 16, /* Wait for glock to be unlocked */
 	GLF_TRY_TO_EVICT		= 17, /* iopen glocks only */
 	GLF_VERIFY_DELETE		= 18, /* iopen glocks only */
+	GLF_PENDING_REPLY		= 19,
 };
 
 struct gfs2_glock {

fs/gfs2/trace_gfs2.h

@@ -53,6 +53,7 @@
 	{(1UL << GLF_DIRTY),			"y" },		\
 	{(1UL << GLF_LFLUSH),			"f" },		\
 	{(1UL << GLF_INVALIDATE_IN_PROGRESS),	"i" },		\
+	{(1UL << GLF_PENDING_REPLY),		"R" },		\
 	{(1UL << GLF_HAVE_REPLY),		"r" },		\
 	{(1UL << GLF_INITIAL),			"a" },		\
 	{(1UL << GLF_HAVE_FROZEN_REPLY),	"F" },		\