ocfs2: Add a name indexed b-tree to directory inodes

This patch makes use of Ocfs2's flexible btree code to add an additional
tree to directory inodes. The new tree stores an array of small,
fixed-length records in each leaf block. Each record stores a hash value,
and pointer to a block in the traditional (unindexed) directory tree where a
dirent with the given name hash resides. Lookup exclusively uses this tree
to find dirents, thus providing us with constant time name lookups.

Some of the hashing code was copied from ext3. Unfortunately, it has lots of
unfixed checkpatch errors. I left that as-is so that tracking changes would
be easier.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 31 insertions, 14 deletions

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index d3a5a09..0c55071 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -231,8 +231,9 @@ static int ocfs2_mknod(struct inode *dir,
 	struct inode *inode = NULL;
 	struct ocfs2_alloc_context *inode_ac = NULL;
 	struct ocfs2_alloc_context *data_ac = NULL;
-	struct ocfs2_alloc_context *xattr_ac = NULL;
+	struct ocfs2_alloc_context *meta_ac = NULL;
 	int want_clusters = 0;
+	int want_meta = 0;
 	int xattr_credits = 0;
 	struct ocfs2_security_xattr_info si = {
 		.enable = 1,
@@ -308,17 +309,31 @@ static int ocfs2_mknod(struct inode *dir,
 
 	/* calculate meta data/clusters for setting security and acl xattr */
 	status = ocfs2_calc_xattr_init(dir, parent_fe_bh, mode,
-					&si, &want_clusters,
-					&xattr_credits, &xattr_ac);
+				       &si, &want_clusters,
+				       &xattr_credits, &want_meta);
 	if (status < 0) {
 		mlog_errno(status);
 		goto leave;
 	}
 
 	/* Reserve a cluster if creating an extent based directory. */
-	if (S_ISDIR(mode) && !ocfs2_supports_inline_data(osb))
+	if (S_ISDIR(mode) && !ocfs2_supports_inline_data(osb)) {
 		want_clusters += 1;
 
+		/* Dir indexing requires extra space as well */
+		if (ocfs2_supports_indexed_dirs(osb)) {
+			want_clusters++;
+			want_meta++;
+		}
+	}
+
+	status = ocfs2_reserve_new_metadata_blocks(osb, want_meta, &meta_ac);
+	if (status < 0) {
+		if (status != -ENOSPC)
+			mlog_errno(status);
+		goto leave;
+	}
+
 	status = ocfs2_reserve_clusters(osb, want_clusters, &data_ac);
 	if (status < 0) {
 		if (status != -ENOSPC)
@@ -326,8 +341,9 @@ static int ocfs2_mknod(struct inode *dir,
 		goto leave;
 	}
 
-	handle = ocfs2_start_trans(osb, ocfs2_mknod_credits(osb->sb) +
-				   xattr_credits);
+	handle = ocfs2_start_trans(osb, ocfs2_mknod_credits(osb->sb,
+							    S_ISDIR(mode),
+							    xattr_credits));
 	if (IS_ERR(handle)) {
 		status = PTR_ERR(handle);
 		handle = NULL;
@@ -355,7 +371,7 @@ static int ocfs2_mknod(struct inode *dir,
 
 	if (S_ISDIR(mode)) {
 		status = ocfs2_fill_new_dir(osb, handle, dir, inode,
-					    new_fe_bh, data_ac);
+					    new_fe_bh, data_ac, meta_ac);
 		if (status < 0) {
 			mlog_errno(status);
 			goto leave;
@@ -377,7 +393,7 @@ static int ocfs2_mknod(struct inode *dir,
 	}
 
 	status = ocfs2_init_acl(handle, inode, dir, new_fe_bh, parent_fe_bh,
-				xattr_ac, data_ac);
+				meta_ac, data_ac);
 	if (status < 0) {
 		mlog_errno(status);
 		goto leave;
@@ -385,7 +401,7 @@ static int ocfs2_mknod(struct inode *dir,
 
 	if (si.enable) {
 		status = ocfs2_init_security_set(handle, inode, new_fe_bh, &si,
-						 xattr_ac, data_ac);
+						 meta_ac, data_ac);
 		if (status < 0) {
 			mlog_errno(status);
 			goto leave;
@@ -440,8 +456,8 @@ leave:
 	if (data_ac)
 		ocfs2_free_alloc_context(data_ac);
 
-	if (xattr_ac)
-		ocfs2_free_alloc_context(xattr_ac);
+	if (meta_ac)
+		ocfs2_free_alloc_context(meta_ac);
 
 	mlog_exit(status);
 
@@ -463,6 +479,7 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
 	struct ocfs2_extent_list *fel;
 	u64 fe_blkno = 0;
 	u16 suballoc_bit;
+	u16 feat;
 
 	mlog_entry("(0x%p, 0x%p, %d, %lu, '%.*s')\n", dir, dentry,
 		   inode->i_mode, (unsigned long)dev, dentry->d_name.len,
@@ -526,11 +543,11 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
 	fe->i_dtime = 0;
 
 	/*
-	 * If supported, directories start with inline data.
+	 * If supported, directories start with inline data. If inline
+	 * isn't supported, but indexing is, we start them as indexed.
 	 */
+	feat = le16_to_cpu(fe->i_dyn_features);
 	if (S_ISDIR(inode->i_mode) && ocfs2_supports_inline_data(osb)) {
-		u16 feat = le16_to_cpu(fe->i_dyn_features);
-
 		fe->i_dyn_features = cpu_to_le16(feat | OCFS2_INLINE_DATA_FL);
 
 		fe->id2.i_data.id_count = cpu_to_le16(