X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fbtrfs%2Fdir-item.c;h=e9103b3baa49f4309c94eca9e0d7b7069665359c;hb=e206d556c5793ac5e28c0aaba2e07432e5f9a098;hp=e4f30090d640bf74b4ec99a1bdd7148a890d2883;hpb=e02119d5a7b4396c5a872582fddc8bd6d305a70a;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index e4f3009..e9103b3 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -21,6 +21,14 @@
 #include "hash.h"
 #include "transaction.h"
 
+/*
+ * insert a name into a directory, doing overflow properly if there is a hash
+ * collision.  data_size indicates how big the item inserted should be.  On
+ * success a struct btrfs_dir_item pointer is returned, otherwise it is
+ * an ERR_PTR.
+ *
+ * The name is not copied into the dir item, you have to do that yourself.
+ */
 static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
 						   *trans,
 						   struct btrfs_root *root,
@@ -55,13 +63,17 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
 	return (struct btrfs_dir_item *)ptr;
 }
 
+/*
+ * xattrs work a lot like directories, this inserts an xattr item
+ * into the tree
+ */
 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, const char *name,
-			    u16 name_len, const void *data, u16 data_len,
-			    u64 dir)
+			    struct btrfs_root *root,
+			    struct btrfs_path *path, u64 objectid,
+			    const char *name, u16 name_len,
+			    const void *data, u16 data_len)
 {
 	int ret = 0;
-	struct btrfs_path *path;
 	struct btrfs_dir_item *dir_item;
 	unsigned long name_ptr, data_ptr;
 	struct btrfs_key key, location;
@@ -69,15 +81,11 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
 	struct extent_buffer *leaf;
 	u32 data_size;
 
-	key.objectid = dir;
+	BUG_ON(name_len + data_len > BTRFS_MAX_XATTR_SIZE(root));
+
+	key.objectid = objectid;
 	btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
 	key.offset = btrfs_name_hash(name, name_len);
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-	if (name_len + data_len + sizeof(struct btrfs_dir_item) >
-	    BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
-		return -ENOSPC;
 
 	data_size = sizeof(*dir_item) + name_len + data_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
@@ -105,10 +113,16 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
 	write_extent_buffer(leaf, data, data_ptr, data_len);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 
-	btrfs_free_path(path);
 	return ret;
 }
 
+/*
+ * insert a directory item in the tree, doing all the magic for
+ * both indexes. 'dir' indicates which objectid to insert it into,
+ * 'location' is the key to stuff into the directory item, 'type' is the
+ * type of the inode we're pointing to, and 'index' is the sequence number
+ * to use for the second index (if one is created).
+ */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 			  *root, const char *name, int name_len, u64 dir,
 			  struct btrfs_key *location, u8 type, u64 index)
@@ -126,7 +140,10 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	key.objectid = dir;
 	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 	key.offset = btrfs_name_hash(name, name_len);
+
 	path = btrfs_alloc_path();
+	path->leave_spinning = 1;
+
 	data_size = sizeof(*dir_item) + name_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 					name, name_len);
@@ -184,6 +201,11 @@ out:
 	return 0;
 }
 
+/*
+ * lookup a directory item based on name.  'dir' is the objectid
+ * we're searching in, and 'mod' tells us if you plan on deleting the
+ * item (use mod < 0) or changing the options (use mod > 0)
+ */
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
 					     struct btrfs_path *path, u64 dir,
@@ -222,6 +244,14 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 	return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
+/*
+ * lookup a directory item based on index.  'dir' is the objectid
+ * we're searching in, and 'mod' tells us if you plan on deleting the
+ * item (use mod < 0) or changing the options (use mod > 0)
+ *
+ * The name is used to make sure the index really points to the name you were
+ * looking for.
+ */
 struct btrfs_dir_item *
 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
@@ -246,6 +276,53 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 	return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
+struct btrfs_dir_item *
+btrfs_search_dir_index_item(struct btrfs_root *root,
+			    struct btrfs_path *path, u64 dirid,
+			    const char *name, int name_len)
+{
+	struct extent_buffer *leaf;
+	struct btrfs_dir_item *di;
+	struct btrfs_key key;
+	u32 nritems;
+	int ret;
+
+	key.objectid = dirid;
+	key.type = BTRFS_DIR_INDEX_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	leaf = path->nodes[0];
+	nritems = btrfs_header_nritems(leaf);
+
+	while (1) {
+		if (path->slots[0] >= nritems) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret < 0)
+				return ERR_PTR(ret);
+			if (ret > 0)
+				break;
+			leaf = path->nodes[0];
+			nritems = btrfs_header_nritems(leaf);
+			continue;
+		}
+
+		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+		if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY)
+			break;
+
+		di = btrfs_match_dir_item_name(root, path, name, name_len);
+		if (di)
+			return di;
+
+		path->slots[0]++;
+	}
+	return NULL;
+}
+
 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 					  struct btrfs_root *root,
 					  struct btrfs_path *path, u64 dir,
@@ -282,6 +359,11 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 	return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
+/*
+ * helper function to look at the directory item pointed to by 'path'
+ * this walks through all the entries in a dir item and finds one
+ * for a specific name.
+ */
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 			      struct btrfs_path *path,
 			      const char *name, int name_len)
@@ -296,7 +378,7 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 	leaf = path->nodes[0];
 	dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
 	total_len = btrfs_item_size_nr(leaf, path->slots[0]);
-	while(cur < total_len) {
+	while (cur < total_len) {
 		this_len = sizeof(*dir_item) +
 			btrfs_dir_name_len(leaf, dir_item) +
 			btrfs_dir_data_len(leaf, dir_item);
@@ -313,6 +395,10 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 	return NULL;
 }
 
+/*
+ * given a pointer into a directory item, delete it.  This
+ * handles items that have more than one entry in them.
+ */
 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct btrfs_path *path,