Commit fd70ab71 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher
Browse files

gfs2: Further sanitize lock_dlm.c 



The gl_req field and GLF_BLOCKING flag are only relevant to gdlm_lock(),
its callback gdlm_ast(), and their helpers, so set and clear them inside
lock_dlm.c.

Also, the LM_FLAG_ANY flag is relevant to gdlm_lock(), but do_xmote()
doesn't pass that flag down to gdlm_lock() as it should.  Fix that by
passing down all the flags.

In addition, document the effect of the LM_FLAG_ANY flag on locks held
in EX mode locally.

Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: default avatarAndrew Price <anprice@redhat.com>
parent cd718046

fs/gfs2/glock.c

+0 −6
Original line number Diff line number Diff line
@@ -717,12 +717,6 @@ __acquires(&gl->gl_lockref.lock) 
			return;

		do_error(gl, 0); /* Fail queued try locks */

	}

	gl->gl_req = target;

	set_bit(GLF_BLOCKING, &gl->gl_flags);

	if ((gl->gl_req == LM_ST_UNLOCKED) ||

	    (gl->gl_state == LM_ST_EXCLUSIVE) ||

	    (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))

		clear_bit(GLF_BLOCKING, &gl->gl_flags);

	if (!glops->go_inval && !glops->go_sync)

		goto skip_inval;

fs/gfs2/glock.h

+4 −0
Original line number Diff line number Diff line
@@ -68,6 +68,10 @@ enum { 
 * also be granted in SHARED.  The preferred state is whichever is compatible

 * with other granted locks, or the specified state if no other locks exist.

 *

 * In addition, when a lock is already held in EX mode locally, a SHARED or

 * DEFERRED mode request with the LM_FLAG_ANY flag set will be granted.

 * (The LM_FLAG_ANY flag is only use for SHARED mode requests currently.)

 *

 * LM_FLAG_NODE_SCOPE

 * This holder agrees to share the lock within this node. In other words,

 * the glock is held in EX mode according to DLM, but local holders on the

fs/gfs2/lock_dlm.c

+18 −8
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index, 
/**

 * gfs2_update_reply_times - Update locking statistics

 * @gl: The glock to update

 * @blocking: The operation may have been blocking

 *

 * This assumes that gl->gl_dstamp has been set earlier.

 *
@@ -72,12 +73,12 @@ static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index, 
 * TRY_1CB flags are set are classified as non-blocking. All

 * other DLM requests are counted as (potentially) blocking.

 */

static inline void gfs2_update_reply_times(struct gfs2_glock *gl)

static inline void gfs2_update_reply_times(struct gfs2_glock *gl,

					   bool blocking)

{

	struct gfs2_pcpu_lkstats *lks;

	const unsigned gltype = gl->gl_name.ln_type;

	unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?

			 GFS2_LKS_SRTTB : GFS2_LKS_SRTT;

	unsigned index = blocking ? GFS2_LKS_SRTTB : GFS2_LKS_SRTT;

	s64 rtt;



	preempt_disable();
@@ -119,14 +120,18 @@ static inline void gfs2_update_request_times(struct gfs2_glock *gl) 
static void gdlm_ast(void *arg)

{

	struct gfs2_glock *gl = arg;

	bool blocking;

	unsigned ret;



	blocking = test_bit(GLF_BLOCKING, &gl->gl_flags);

	gfs2_update_reply_times(gl, blocking);

	clear_bit(GLF_BLOCKING, &gl->gl_flags);



	/* If the glock is dead, we only react to a dlm_unlock() reply. */

	if (__lockref_is_dead(&gl->gl_lockref) &&

	    gl->gl_lksb.sb_status != -DLM_EUNLOCK)

		return;



	gfs2_update_reply_times(gl);

	BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);



	if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
@@ -241,7 +246,7 @@ static bool down_conversion(int cur, int req) 
}



static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,

		      const int cur, const int req)

		      const int req, bool blocking)

{

	u32 lkf = 0;
@@ -274,7 +279,7 @@ static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags, 
		 * "upward" lock conversions or else DLM will reject the

		 * request as invalid.

		 */

		if (!down_conversion(cur, req))

		if (blocking)

			lkf |= DLM_LKF_QUECVT;

	}
@@ -294,14 +299,20 @@ static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state, 
		     unsigned int flags)

{

	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;

	bool blocking;

	int cur, req;

	u32 lkf;

	char strname[GDLM_STRNAME_BYTES] = "";

	int error;



	gl->gl_req = req_state;

	cur = make_mode(gl->gl_name.ln_sbd, gl->gl_state);

	req = make_mode(gl->gl_name.ln_sbd, req_state);

	lkf = make_flags(gl, flags, cur, req);

	blocking = !down_conversion(cur, req) &&

		   !(flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB));

	lkf = make_flags(gl, flags, req, blocking);

	if (blocking)

		set_bit(GLF_BLOCKING, &gl->gl_flags);

	gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);

	gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);

	if (test_bit(GLF_INITIAL, &gl->gl_flags)) {
@@ -341,7 +352,6 @@ static void gdlm_put_lock(struct gfs2_glock *gl) 
		return;

	}



	clear_bit(GLF_BLOCKING, &gl->gl_flags);

	gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);

	gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);

	gfs2_update_request_times(gl);