commit 73be192b17e43b6dc4f492dab41d70ab5b9d2908
author Joel Becker <joel.becker@oracle.com> Tue Jan 06 14:57:08 2009 -0800
committer Joel Becker <joel.becker@oracle.com> Wed Jun 03 19:15:36 2009 -0700
tree 9482070421cda81f490036b28033d4f300a58a94
parent 15633a220ffe74fc61bc8117e6a89a494011ea3d

ocfs2: Add statistics for the checksum and ecc operations.

It would be nice to know how often we get checksum failures.  Even
better, how many of them we can fix with the single bit ecc.  So, we add
a statistics structure.  The structure can be installed into debugfs
wherever the user wants.

For ocfs2, we'll put it in the superblock-specific debugfs directory and
pass it down from our higher-level functions.  The stats are only
registered with debugfs when the filesystem supports metadata ecc.

Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/super.c

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index d05f3ca..86f500c 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -118,10 +118,12 @@
 static int ocfs2_check_volume(struct ocfs2_super *osb);
 static int ocfs2_verify_volume(struct ocfs2_dinode *di,
 			       struct buffer_head *bh,
-			       u32 sectsize);
+			       u32 sectsize,
+			       struct ocfs2_blockcheck_stats *stats);
 static int ocfs2_initialize_super(struct super_block *sb,
 				  struct buffer_head *bh,
-				  int sector_size);
+				  int sector_size,
+				  struct ocfs2_blockcheck_stats *stats);
 static int ocfs2_get_sector(struct super_block *sb,
 			    struct buffer_head **bh,
 			    int block,
@@ -711,7 +713,8 @@
 
 static int ocfs2_sb_probe(struct super_block *sb,
 			  struct buffer_head **bh,
-			  int *sector_size)
+			  int *sector_size,
+			  struct ocfs2_blockcheck_stats *stats)
 {
 	int status, tmpstat;
 	struct ocfs1_vol_disk_hdr *hdr;
@@ -777,7 +780,8 @@
 			goto bail;
 		}
 		di = (struct ocfs2_dinode *) (*bh)->b_data;
-		status = ocfs2_verify_volume(di, *bh, blksize);
+		memset(stats, 0, sizeof(struct ocfs2_blockcheck_stats));
+		status = ocfs2_verify_volume(di, *bh, blksize, stats);
 		if (status >= 0)
 			goto bail;
 		brelse(*bh);
@@ -983,6 +987,7 @@
 	struct ocfs2_super *osb = NULL;
 	struct buffer_head *bh = NULL;
 	char nodestr[8];
+	struct ocfs2_blockcheck_stats stats;
 
 	mlog_entry("%p, %p, %i", sb, data, silent);
 
@@ -992,13 +997,13 @@
 	}
 
 	/* probe for superblock */
-	status = ocfs2_sb_probe(sb, &bh, &sector_size);
+	status = ocfs2_sb_probe(sb, &bh, &sector_size, &stats);
 	if (status < 0) {
 		mlog(ML_ERROR, "superblock probe failed!\n");
 		goto read_super_error;
 	}
 
-	status = ocfs2_initialize_super(sb, bh, sector_size);
+	status = ocfs2_initialize_super(sb, bh, sector_size, &stats);
 	osb = OCFS2_SB(sb);
 	if (status < 0) {
 		mlog_errno(status);
@@ -1108,6 +1113,18 @@
 		goto read_super_error;
 	}
 
+	if (ocfs2_meta_ecc(osb)) {
+		status = ocfs2_blockcheck_stats_debugfs_install(
+						&osb->osb_ecc_stats,
+						osb->osb_debug_root);
+		if (status) {
+			mlog(ML_ERROR,
+			     "Unable to create blockcheck statistics "
+			     "files\n");
+			goto read_super_error;
+		}
+	}
+
 	status = ocfs2_mount_volume(sb);
 	if (osb->root_inode)
 		inode = igrab(osb->root_inode);
@@ -1849,6 +1866,7 @@
 	if (osb->cconn)
 		ocfs2_dlm_shutdown(osb, hangup_needed);
 
+	ocfs2_blockcheck_stats_debugfs_remove(&osb->osb_ecc_stats);
 	debugfs_remove(osb->osb_debug_root);
 
 	if (hangup_needed)
@@ -1896,7 +1914,8 @@
 
 static int ocfs2_initialize_super(struct super_block *sb,
 				  struct buffer_head *bh,
-				  int sector_size)
+				  int sector_size,
+				  struct ocfs2_blockcheck_stats *stats)
 {
 	int status;
 	int i, cbits, bbits;
@@ -1955,6 +1974,9 @@
 	atomic_set(&osb->alloc_stats.bg_allocs, 0);
 	atomic_set(&osb->alloc_stats.bg_extends, 0);
 
+	/* Copy the blockcheck stats from the superblock probe */
+	osb->osb_ecc_stats = *stats;
+
 	ocfs2_init_node_maps(osb);
 
 	snprintf(osb->dev_str, sizeof(osb->dev_str), "%u,%u",
@@ -2192,7 +2214,8 @@
  */
 static int ocfs2_verify_volume(struct ocfs2_dinode *di,
 			       struct buffer_head *bh,
-			       u32 blksz)
+			       u32 blksz,
+			       struct ocfs2_blockcheck_stats *stats)
 {
 	int status = -EAGAIN;
 
@@ -2205,7 +2228,8 @@
 		    OCFS2_FEATURE_INCOMPAT_META_ECC) {
 			status = ocfs2_block_check_validate(bh->b_data,
 							    bh->b_size,
-							    &di->i_check);
+							    &di->i_check,
+							    stats);
 			if (status)
 				goto out;
 		}