[GFS2] Fix bug in directory code and tidy up

Due to a typo, the dir leaf split operation was (for the first
split in a directory) writing the new hash vaules at the
wrong offset. This is now fixed.

Also some other tidy ups are included:

 - We use GFS2's hash function for dentries (see ops_dentry.c) so that
   we don't have to keep recalculating the hash values.
 - A lot of common code is eliminated between the various directory
   lookup routines.
 - Better error checking on directory lookup (previously different
   routines checked for different errors)
 - The leaf split operation has a couple of redundant operations
   removed from it, so it should be faster.

There is still further scope for further clean ups in the directory
code, and readdir in particular could do with slimming down a bit.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 40 insertions, 23 deletions

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index cd1de61bff2f..d403d51d5b0f 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -228,12 +228,10 @@ struct inode *gfs2_iget(struct super_block *sb, struct gfs2_inum *inum)
 
 void gfs2_inode_min_init(struct gfs2_inode *ip, unsigned int type)
 {
-	spin_lock(&ip->i_spin);
 	if (!test_and_set_bit(GIF_MIN_INIT, &ip->i_flags)) {
 		ip->i_di.di_nlink = 1;
 		ip->i_di.di_mode = DT2IF(type);
 	}
-	spin_unlock(&ip->i_spin);
 }
 
 /**
@@ -257,10 +255,8 @@ int gfs2_inode_refresh(struct gfs2_inode *ip)
 		return -EIO;
 	}
 
-	spin_lock(&ip->i_spin);
 	gfs2_dinode_in(&ip->i_di, dibh->b_data);
 	set_bit(GIF_MIN_INIT, &ip->i_flags);
-	spin_unlock(&ip->i_spin);
 
 	brelse(dibh);
 
@@ -702,6 +698,16 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
 	return 0;
 }
 
+struct inode *gfs2_lookup_simple(struct inode *dip, const char *name)
+{
+	struct qstr qstr;
+	qstr.name = name;
+	qstr.len = strlen(name);
+	qstr.hash = gfs2_disk_hash(qstr.name, qstr.len);
+	return gfs2_lookupi(dip, &qstr, 1, NULL);
+}
+
+
 /**
  * gfs2_lookupi - Look up a filename in a directory and return its inode
  * @d_gh: An initialized holder for the directory glock
@@ -715,8 +721,9 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
  * Returns: errno
  */
 
-int gfs2_lookupi(struct inode *dir, struct qstr *name, int is_root,
-		 struct inode **inodep)
+struct inode *gfs2_lookupi(struct inode *dir, struct qstr *name, int is_root,
+			   struct nameidata *nd)
+		 
 {
 	struct super_block *sb = dir->i_sb;
 	struct gfs2_inode *ipp;
@@ -727,14 +734,14 @@ int gfs2_lookupi(struct inode *dir, struct qstr *name, int is_root,
 	unsigned int type;
 	struct gfs2_glock *gl;
 	int error = 0;
-
-	*inodep = NULL;
+	struct inode *inode = NULL;
 
 	if (!name->len || name->len > GFS2_FNAMESIZE)
-		return -ENAMETOOLONG;
+		return ERR_PTR(-ENAMETOOLONG);
 
-	if (gfs2_filecmp(name, ".", 1) ||
-	    (gfs2_filecmp(name, "..", 2) && dir == sb->s_root->d_inode)) {
+	if ((name->len == 1 && memcmp(name->name, ".", 1) == 0) ||
+	    (name->len == 2 && memcmp(name->name, "..", 2) == 0 &&
+	     dir == sb->s_root->d_inode)) {
 		gfs2_inode_hold(dip);
 		ipp = dip;
 		goto done;
@@ -742,7 +749,7 @@ int gfs2_lookupi(struct inode *dir, struct qstr *name, int is_root,
 
 	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
 	if (error)
-		return error;
+		return ERR_PTR(error);
 
 	if (!is_root) {
 		error = gfs2_repermission(dip->i_vnode, MAY_EXEC, NULL);
@@ -750,7 +757,7 @@ int gfs2_lookupi(struct inode *dir, struct qstr *name, int is_root,
 			goto out;
 	}
 
-	error = gfs2_dir_search(dip, name, &inum, &type);
+	error = gfs2_dir_search(dir, name, &inum, &type);
 	if (error)
 		goto out;
 
@@ -768,13 +775,16 @@ int gfs2_lookupi(struct inode *dir, struct qstr *name, int is_root,
 out:
 	gfs2_glock_dq_uninit(&d_gh);
 done:
+	if (error == -ENOENT)
+		return NULL;
 	if (error == 0) {
-		*inodep = gfs2_ip2v(ipp);
-		if (!*inodep)
-			error = -ENOMEM;
+		inode = gfs2_ip2v(ipp);
 		gfs2_inode_put(ipp);
+		if (!inode)
+			return ERR_PTR(-ENOMEM);
+		return inode;
 	}
-	return error;
+	return ERR_PTR(error);
 }
 
 static int pick_formal_ino_1(struct gfs2_sbd *sdp, uint64_t *formal_ino)
@@ -918,7 +928,7 @@ static int create_ok(struct gfs2_inode *dip, struct qstr *name,
 	if (!dip->i_di.di_nlink)
 		return -EPERM;
 
-	error = gfs2_dir_search(dip, name, NULL, NULL);
+	error = gfs2_dir_search(dip->i_vnode, name, NULL, NULL);
 	switch (error) {
 	case -ENOENT:
 		error = 0;
@@ -1116,7 +1126,9 @@ static int link_dinode(struct gfs2_inode *dip, struct qstr *name,
 	if (error)
 		goto fail;
 
-	error = gfs2_diradd_alloc_required(dip, name, &alloc_required);
+	error = alloc_required = gfs2_diradd_alloc_required(dip->i_vnode, name);
+	if (alloc_required < 0)
+		goto fail;
 	if (alloc_required) {
 		error = gfs2_quota_check(dip, dip->i_di.di_uid,
 					 dip->i_di.di_gid);
@@ -1145,7 +1157,7 @@ static int link_dinode(struct gfs2_inode *dip, struct qstr *name,
 			goto fail_quota_locks;
 	}
 
-	error = gfs2_dir_add(dip, name, &ip->i_num, IF2DT(ip->i_di.di_mode));
+	error = gfs2_dir_add(dip->i_vnode, name, &ip->i_num, IF2DT(ip->i_di.di_mode));
 	if (error)
 		goto fail_end_trans;
 
@@ -1379,12 +1391,14 @@ int gfs2_rmdiri(struct gfs2_inode *dip, struct qstr *name,
 
 	dotname.len = 1;
 	dotname.name = ".";
+	dotname.hash = gfs2_disk_hash(dotname.name, dotname.len);
 	error = gfs2_dir_del(ip, &dotname);
 	if (error)
 		return error;
 
 	dotname.len = 2;
 	dotname.name = "..";
+	dotname.hash = gfs2_disk_hash(dotname.name, dotname.len);
 	error = gfs2_dir_del(ip, &dotname);
 	if (error)
 		return error;
@@ -1439,7 +1453,7 @@ int gfs2_unlink_ok(struct gfs2_inode *dip, struct qstr *name,
 	if (error)
 		return error;
 
-	error = gfs2_dir_search(dip, name, &inum, &type);
+	error = gfs2_dir_search(dip->i_vnode, name, &inum, &type);
 	if (error)
 		return error;
 
@@ -1476,6 +1490,7 @@ int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
 	memset(&dotdot, 0, sizeof(struct qstr));
 	dotdot.name = "..";
 	dotdot.len = 2;
+	dotdot.hash = gfs2_disk_hash(dotdot.name, dotdot.len);
 
 	igrab(dir);
 
@@ -1489,9 +1504,11 @@ int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
 			break;
 		}
 
-		error = gfs2_lookupi(dir, &dotdot, 1, &tmp);
-		if (error)
+		tmp = gfs2_lookupi(dir, &dotdot, 1, NULL);
+		if (IS_ERR(tmp)) {
+			error = PTR_ERR(tmp);
 			break;
+		}
 
 		iput(dir);
 		dir = tmp;