gfs2: Dump nrpages for inodes and their glocks

This patch is based on an idea from Steve Whitehouse. The idea is
to dump the number of pages for inodes in the glock dumps.
The additional locking required me to drop const from quite a few
places.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -1777,7 +1777,7 @@ static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
  *
  */
 
-void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
+void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
 {
 	const struct gfs2_glock_operations *glops = gl->gl_ops;
 	unsigned long long dtime;

fs/gfs2/glock.h

@@ -202,7 +202,7 @@ extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
 			     struct gfs2_holder *gh);
 extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
-extern void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
+extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl);
 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { gfs2_dump_glock(NULL, gl); BUG(); } } while(0)
 extern __printf(2, 3)
 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);

fs/gfs2/glops.c

@@ -467,17 +467,25 @@ static int inode_go_lock(struct gfs2_holder *gh)
  *
  */
 
-static void inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
+static void inode_go_dump(struct seq_file *seq, struct gfs2_glock *gl)
 {
-	const struct gfs2_inode *ip = gl->gl_object;
+	struct gfs2_inode *ip = gl->gl_object;
+	struct inode *inode = &ip->i_inode;
+	unsigned long nrpages;
+
 	if (ip == NULL)
 		return;
-	gfs2_print_dbg(seq, " I: n:%llu/%llu t:%u f:0x%02lx d:0x%08x s:%llu\n",
+
+	xa_lock_irq(&inode->i_data.i_pages);
+	nrpages = inode->i_data.nrpages;
+	xa_unlock_irq(&inode->i_data.i_pages);
+
+	gfs2_print_dbg(seq, " I: n:%llu/%llu t:%u f:0x%02lx d:0x%08x s:%llu p:%lu\n",
 		  (unsigned long long)ip->i_no_formal_ino,
 		  (unsigned long long)ip->i_no_addr,
 		  IF2DT(ip->i_inode.i_mode), ip->i_flags,
 		  (unsigned int)ip->i_diskflags,
-		  (unsigned long long)i_size_read(&ip->i_inode));
+		  (unsigned long long)i_size_read(inode), nrpages);
 }
 
 /**

fs/gfs2/incore.h

@@ -243,7 +243,7 @@ struct gfs2_glock_operations {
 	int (*go_demote_ok) (const struct gfs2_glock *gl);
 	int (*go_lock) (struct gfs2_holder *gh);
 	void (*go_unlock) (struct gfs2_holder *gh);
-	void (*go_dump)(struct seq_file *seq, const struct gfs2_glock *gl);
+	void (*go_dump)(struct seq_file *seq, struct gfs2_glock *gl);
 	void (*go_callback)(struct gfs2_glock *gl, bool remote);
 	const int go_type;
 	const unsigned long go_flags;

fs/gfs2/rgrp.c

@@ -2256,7 +2256,7 @@ static void rgblk_free(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd,
  *
  */
 
-void gfs2_rgrp_dump(struct seq_file *seq, const struct gfs2_glock *gl)
+void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_glock *gl)
 {
 	struct gfs2_rgrpd *rgd = gl->gl_object;
 	struct gfs2_blkreserv *trs;

fs/gfs2/rgrp.h

@@ -72,7 +72,7 @@ extern void gfs2_rlist_add(struct gfs2_inode *ip, struct gfs2_rgrp_list *rlist,
 extern void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist);
 extern void gfs2_rlist_free(struct gfs2_rgrp_list *rlist);
 extern u64 gfs2_ri_total(struct gfs2_sbd *sdp);
-extern void gfs2_rgrp_dump(struct seq_file *seq, const struct gfs2_glock *gl);
+extern void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_glock *gl);
 extern int gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
 				   struct buffer_head *bh,
 				   const struct gfs2_bitmap *bi, unsigned minlen, u64 *ptrimmed);