From: NeilBrown <neilb@suse.de>
Date: Fri, 25 Jun 2010 10:34:52 +0000 (+1000)
Subject: Add debug tracing to unlink.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=36b1cad4d881f6e88141d5b35d5a0e8c08bdfe65;p=LaFS.git

Add debug tracing to unlink.

Have had strange code of unlink failing to find the target
file.  So add lots of tracing in the hope that it will happen
again.
It might be sensitive to the hash chosen.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/dir.c b/dir.c
index e492985..39f4d91 100644
--- a/dir.c
+++ b/dir.c
@@ -48,12 +48,15 @@ dir_lookup_blk(struct inode *dir, const char *name, int nlen,
 		nlen = strlen(name);
 
 	hash = lafs_hash_name(seed, nlen, name);
+	dprintk("name= %s hash=%lu\n", name, (unsigned long)bn);
 
 	while (1) {
 		char *buf;
 		bn = hash+1;
+		dprintk("bn=%lu\n", (unsigned long)bn);
 		if (lafs_find_next(dir, &bn) == 0)
 			bn = 0;
+		dprintk("now=%lu\n", (unsigned long)bn);
 
 		err = -ENOMEM;
 		b = lafs_get_block(dir, bn, NULL, GFP_KERNEL, REF);
@@ -63,6 +66,10 @@ dir_lookup_blk(struct inode *dir, const char *name, int nlen,
 		if (err)
 			break;
 		buf = map_dblock(b);
+		if (lafs_trace) {
+			void lafs_dir_print(char *buf, int psz);
+			lafs_dir_print(buf, bits);
+		}
 		for ( ; hash < (bn ? bn : MaxDirHash) ; hash++) {
 			u8 piece;
 			struct dir_ent de;
@@ -377,6 +384,15 @@ dir_delete_prepare(struct fs *fs, struct inode *dir,
 	doh->dirent_block =
 		dirblk = dir_lookup_blk(dir, name, nlen, &doh->index,
 					0, &doh->hash, MKREF(dir_blk));
+	if (IS_ERR(dirblk) && PTR_ERR(dirblk) == -ENOENT) {
+		lafs_trace = 1;
+		dirblk = dir_lookup_blk(dir, name, nlen, &doh->index,
+					0, &doh->hash, MKREF(dir_blk));
+		if (!IS_ERR(dirblk))
+			printk("Weird: %s\n", strblk(&dirblk->b));
+		lafs_trace = 0;
+	}
+	
 	if (IS_ERR(dirblk))
 		return PTR_ERR(dirblk);
 
@@ -704,6 +720,7 @@ lafs_unlink(struct inode *dir, struct dentry *de)
 
 	err = dir_delete_prepare(fs, dir, de->d_name.name, de->d_name.len,
 				 &doh);
+	BUG_ON(err == -ENOENT);
 	err = dir_log_prepare(&uh, fs, &de->d_name) ?: err;
 	inodb = lafs_inode_dblock(inode, SYNC, MKREF(inode_update));
 	if (IS_ERR(inodb))