GFS2: Move glock superblock pointer to field gl_name

What uniquely identifies a glock in the glock hash table is not
gl_name, but gl_name and its superblock pointer. This patch makes
the gl_name field correspond to a unique glock identifier. That will
allow us to simplify hashing with a future patch, since the hash
algorithm can then take the gl_name and hash its components in one
operation.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/glock.c

@@ -119,7 +119,7 @@ static void gfs2_glock_dealloc(struct rcu_head *rcu)
 
 void gfs2_glock_free(struct gfs2_glock *gl)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
 	call_rcu(&gl->gl_rcu, gfs2_glock_dealloc);
 	if (atomic_dec_and_test(&sdp->sd_glock_disposal))
@@ -192,7 +192,7 @@ static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
 
 void gfs2_glock_put(struct gfs2_glock *gl)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct address_space *mapping = gfs2_glock2aspace(gl);
 
 	if (lockref_put_or_lock(&gl->gl_lockref))
@@ -220,7 +220,6 @@ void gfs2_glock_put(struct gfs2_glock *gl)
  */
 
 static struct gfs2_glock *search_bucket(unsigned int hash,
-					const struct gfs2_sbd *sdp,
 					const struct lm_lockname *name)
 {
 	struct gfs2_glock *gl;
@@ -229,8 +228,6 @@ static struct gfs2_glock *search_bucket(unsigned int hash,
 	hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) {
 		if (!lm_name_equal(&gl->gl_name, name))
 			continue;
-		if (gl->gl_sbd != sdp)
-			continue;
 		if (lockref_get_not_dead(&gl->gl_lockref))
 			return gl;
 	}
@@ -506,7 +503,7 @@ __releases(&gl->gl_spin)
 __acquires(&gl->gl_spin)
 {
 	const struct gfs2_glock_operations *glops = gl->gl_ops;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	unsigned int lck_flags = gh ? gh->gh_flags : 0;
 	int ret;
 
@@ -628,7 +625,7 @@ __acquires(&gl->gl_spin)
 static void delete_work_func(struct work_struct *work)
 {
 	struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_inode *ip;
 	struct inode *inode;
 	u64 no_addr = gl->gl_name.ln_number;
@@ -704,14 +701,16 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 		   struct gfs2_glock **glp)
 {
 	struct super_block *s = sdp->sd_vfs;
-	struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
+	struct lm_lockname name = { .ln_number = number,
+				    .ln_type = glops->go_type,
+				    .ln_sbd = sdp };
 	struct gfs2_glock *gl, *tmp;
 	unsigned int hash = gl_hash(sdp, &name);
 	struct address_space *mapping;
 	struct kmem_cache *cachep;
 
 	rcu_read_lock();
-	gl = search_bucket(hash, sdp, &name);
+	gl = search_bucket(hash, &name);
 	rcu_read_unlock();
 
 	*glp = gl;
@@ -739,7 +738,6 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 	}
 
 	atomic_inc(&sdp->sd_glock_disposal);
-	gl->gl_sbd = sdp;
 	gl->gl_flags = 0;
 	gl->gl_name = name;
 	gl->gl_lockref.count = 1;
@@ -772,7 +770,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 	}
 
 	spin_lock_bucket(hash);
-	tmp = search_bucket(hash, sdp, &name);
+	tmp = search_bucket(hash, &name);
 	if (tmp) {
 		spin_unlock_bucket(hash);
 		kfree(gl->gl_lksb.sb_lvbptr);
@@ -928,7 +926,7 @@ __releases(&gl->gl_spin)
 __acquires(&gl->gl_spin)
 {
 	struct gfs2_glock *gl = gh->gh_gl;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct list_head *insert_pt = NULL;
 	struct gfs2_holder *gh2;
 	int try_futile = 0;
@@ -1006,7 +1004,7 @@ __acquires(&gl->gl_spin)
 int gfs2_glock_nq(struct gfs2_holder *gh)
 {
 	struct gfs2_glock *gl = gh->gh_gl;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	int error = 0;
 
 	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
@@ -1313,7 +1311,7 @@ static int gfs2_should_freeze(const struct gfs2_glock *gl)
 
 void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
 {
-	struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
+	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 
 	spin_lock(&gl->gl_spin);
 	gl->gl_reply = ret;
@@ -1471,7 +1469,7 @@ static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
 
 	rcu_read_lock();
 	hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
-		if ((gl->gl_sbd == sdp) && lockref_get_not_dead(&gl->gl_lockref))
+		if ((gl->gl_name.ln_sbd == sdp) && lockref_get_not_dead(&gl->gl_lockref))
 			examiner(gl);
 	}
 	rcu_read_unlock();
@@ -1569,7 +1567,7 @@ void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
 	int ret;
 
 	ret = gfs2_truncatei_resume(ip);
-	gfs2_assert_withdraw(gl->gl_sbd, ret == 0);
+	gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0);
 
 	spin_lock(&gl->gl_spin);
 	clear_bit(GLF_LOCK, &gl->gl_flags);
@@ -1872,7 +1870,7 @@ static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
 			gi->nhash = 0;
 		}
 	/* Skip entries for other sb and dead entries */
-	} while (gi->sdp != gi->gl->gl_sbd ||
+	} while (gi->sdp != gi->gl->gl_name.ln_sbd ||
 		 __lockref_is_dead(&gi->gl->gl_lockref));
 
 	return 0;

fs/gfs2/glops.c

@@ -32,13 +32,15 @@ struct workqueue_struct *gfs2_freeze_wq;
 
 static void gfs2_ail_error(struct gfs2_glock *gl, const struct buffer_head *bh)
 {
-	fs_err(gl->gl_sbd, "AIL buffer %p: blocknr %llu state 0x%08lx mapping %p page state 0x%lx\n",
+	fs_err(gl->gl_name.ln_sbd,
+	       "AIL buffer %p: blocknr %llu state 0x%08lx mapping %p page "
+	       "state 0x%lx\n",
 	       bh, (unsigned long long)bh->b_blocknr, bh->b_state,
 	       bh->b_page->mapping, bh->b_page->flags);
-	fs_err(gl->gl_sbd, "AIL glock %u:%llu mapping %p\n",
+	fs_err(gl->gl_name.ln_sbd, "AIL glock %u:%llu mapping %p\n",
 	       gl->gl_name.ln_type, gl->gl_name.ln_number,
 	       gfs2_glock2aspace(gl));
-	gfs2_lm_withdraw(gl->gl_sbd, "AIL error\n");
+	gfs2_lm_withdraw(gl->gl_name.ln_sbd, "AIL error\n");
 }
 
 /**
@@ -52,7 +54,7 @@ static void gfs2_ail_error(struct gfs2_glock *gl, const struct buffer_head *bh)
 static void __gfs2_ail_flush(struct gfs2_glock *gl, bool fsync,
 			     unsigned int nr_revokes)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct list_head *head = &gl->gl_ail_list;
 	struct gfs2_bufdata *bd, *tmp;
 	struct buffer_head *bh;
@@ -80,7 +82,7 @@ static void __gfs2_ail_flush(struct gfs2_glock *gl, bool fsync,
 
 static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_trans tr;
 
 	memset(&tr, 0, sizeof(tr));
@@ -109,7 +111,7 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 
 void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	unsigned int revokes = atomic_read(&gl->gl_ail_count);
 	unsigned int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
 	int ret;
@@ -139,7 +141,7 @@ void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
 
 static void rgrp_go_sync(struct gfs2_glock *gl)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct address_space *mapping = &sdp->sd_aspace;
 	struct gfs2_rgrpd *rgd;
 	int error;
@@ -179,7 +181,7 @@ static void rgrp_go_sync(struct gfs2_glock *gl)
 
 static void rgrp_go_inval(struct gfs2_glock *gl, int flags)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct address_space *mapping = &sdp->sd_aspace;
 	struct gfs2_rgrpd *rgd = gl->gl_object;
 
@@ -218,7 +220,7 @@ static void inode_go_sync(struct gfs2_glock *gl)
 
 	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-	gfs2_log_flush(gl->gl_sbd, gl, NORMAL_FLUSH);
+	gfs2_log_flush(gl->gl_name.ln_sbd, gl, NORMAL_FLUSH);
 	filemap_fdatawrite(metamapping);
 	if (ip) {
 		struct address_space *mapping = ip->i_inode.i_mapping;
@@ -252,7 +254,7 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags)
 {
 	struct gfs2_inode *ip = gl->gl_object;
 
-	gfs2_assert_withdraw(gl->gl_sbd, !atomic_read(&gl->gl_ail_count));
+	gfs2_assert_withdraw(gl->gl_name.ln_sbd, !atomic_read(&gl->gl_ail_count));
 
 	if (flags & DIO_METADATA) {
 		struct address_space *mapping = gfs2_glock2aspace(gl);
@@ -264,9 +266,9 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags)
 		}
 	}
 
-	if (ip == GFS2_I(gl->gl_sbd->sd_rindex)) {
-		gfs2_log_flush(gl->gl_sbd, NULL, NORMAL_FLUSH);
-		gl->gl_sbd->sd_rindex_uptodate = 0;
+	if (ip == GFS2_I(gl->gl_name.ln_sbd->sd_rindex)) {
+		gfs2_log_flush(gl->gl_name.ln_sbd, NULL, NORMAL_FLUSH);
+		gl->gl_name.ln_sbd->sd_rindex_uptodate = 0;
 	}
 	if (ip && S_ISREG(ip->i_inode.i_mode))
 		truncate_inode_pages(ip->i_inode.i_mapping, 0);
@@ -281,7 +283,7 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags)
 
 static int inode_go_demote_ok(const struct gfs2_glock *gl)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_holder *gh;
 
 	if (sdp->sd_jindex == gl->gl_object || sdp->sd_rindex == gl->gl_object)
@@ -416,7 +418,7 @@ int gfs2_inode_refresh(struct gfs2_inode *ip)
 static int inode_go_lock(struct gfs2_holder *gh)
 {
 	struct gfs2_glock *gl = gh->gh_gl;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_inode *ip = gl->gl_object;
 	int error = 0;
 
@@ -477,7 +479,7 @@ static void inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
 static void freeze_go_sync(struct gfs2_glock *gl)
 {
 	int error = 0;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
 	if (gl->gl_state == LM_ST_SHARED &&
 	    test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
@@ -500,7 +502,7 @@ static void freeze_go_sync(struct gfs2_glock *gl)
 
 static int freeze_go_xmote_bh(struct gfs2_glock *gl, struct gfs2_holder *gh)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 	struct gfs2_glock *j_gl = ip->i_gl;
 	struct gfs2_log_header_host head;
@@ -545,7 +547,7 @@ static int freeze_go_demote_ok(const struct gfs2_glock *gl)
 static void iopen_go_callback(struct gfs2_glock *gl, bool remote)
 {
 	struct gfs2_inode *ip = (struct gfs2_inode *)gl->gl_object;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
 	if (!remote || (sdp->sd_vfs->s_flags & MS_RDONLY))
 		return;

fs/gfs2/incore.h

@@ -203,13 +203,15 @@ enum {
 };
 
 struct lm_lockname {
+	struct gfs2_sbd *ln_sbd;
 	u64 ln_number;
 	unsigned int ln_type;
 };
 
 #define lm_name_equal(name1, name2) \
-        (((name1)->ln_number == (name2)->ln_number) && \
-         ((name1)->ln_type == (name2)->ln_type))
+        (((name1)->ln_number == (name2)->ln_number) &&	\
+	 ((name1)->ln_type == (name2)->ln_type) &&	\
+	 ((name1)->ln_sbd == (name2)->ln_sbd))
 
 
 struct gfs2_glock_operations {
@@ -327,7 +329,6 @@ enum {
 
 struct gfs2_glock {
 	struct hlist_bl_node gl_list;
-	struct gfs2_sbd *gl_sbd;
 	unsigned long gl_flags;		/* GLF_... */
 	struct lm_lockname gl_name;
 
@@ -835,7 +836,7 @@ static inline void gfs2_glstats_inc(struct gfs2_glock *gl, int which)
 
 static inline void gfs2_sbstats_inc(const struct gfs2_glock *gl, int which)
 {
-	const struct gfs2_sbd *sdp = gl->gl_sbd;
+	const struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	preempt_disable();
 	this_cpu_ptr(sdp->sd_lkstats)->lkstats[gl->gl_name.ln_type].stats[which]++;
 	preempt_enable();

fs/gfs2/lock_dlm.c

@@ -80,7 +80,7 @@ static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
 
 	preempt_disable();
 	rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
-	lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
+	lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
 	gfs2_update_stats(&gl->gl_stats, index, rtt);		/* Local */
 	gfs2_update_stats(&lks->lkstats[gltype], index, rtt);	/* Global */
 	preempt_enable();
@@ -108,7 +108,7 @@ static inline void gfs2_update_request_times(struct gfs2_glock *gl)
 	dstamp = gl->gl_dstamp;
 	gl->gl_dstamp = ktime_get_real();
 	irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
-	lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
+	lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
 	gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);		/* Local */
 	gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);	/* Global */
 	preempt_enable();
@@ -253,7 +253,7 @@ static void gfs2_reverse_hex(char *c, u64 value)
 static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
 		     unsigned int flags)
 {
-	struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
+	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 	int req;
 	u32 lkf;
 	char strname[GDLM_STRNAME_BYTES] = "";
@@ -281,7 +281,7 @@ static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
 
 static void gdlm_put_lock(struct gfs2_glock *gl)
 {
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 	int lvb_needs_unlock = 0;
 	int error;
@@ -319,7 +319,7 @@ static void gdlm_put_lock(struct gfs2_glock *gl)
 
 static void gdlm_cancel(struct gfs2_glock *gl)
 {
-	struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
+	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 	dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
 }
 

fs/gfs2/lops.c

@@ -70,7 +70,7 @@ static bool buffer_is_rgrp(const struct gfs2_bufdata *bd)
 static void maybe_release_space(struct gfs2_bufdata *bd)
 {
 	struct gfs2_glock *gl = bd->bd_gl;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_rgrpd *rgd = gl->gl_object;
 	unsigned int index = bd->bd_bh->b_blocknr - gl->gl_name.ln_number;
 	struct gfs2_bitmap *bi = rgd->rd_bits + index;
@@ -585,7 +585,7 @@ static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
 static void gfs2_meta_sync(struct gfs2_glock *gl)
 {
 	struct address_space *mapping = gfs2_glock2aspace(gl);
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	int error;
 
 	if (mapping == NULL)
@@ -595,7 +595,7 @@ static void gfs2_meta_sync(struct gfs2_glock *gl)
 	error = filemap_fdatawait(mapping);
 
 	if (error)
-		gfs2_io_error(gl->gl_sbd);
+		gfs2_io_error(gl->gl_name.ln_sbd);
 }
 
 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)