hfsplus: implement attributes file's header node initialization code
Implement functionality of AttributesFile's header node initialization.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index bd8471f..568a45c 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -127,6 +127,71 @@
return 0;
}
+static void hfsplus_init_header_node(struct inode *attr_file,
+ u32 clump_size,
+ char *buf, size_t node_size)
+{
+ struct hfs_bnode_desc *desc;
+ struct hfs_btree_header_rec *head;
+ u16 offset;
+ __be16 *rec_offsets;
+ u32 hdr_node_map_rec_bits;
+ char *bmp;
+ u32 used_nodes;
+ u32 used_bmp_bytes;
+
+ hfs_dbg(ATTR_MOD, "init_hdr_attr_file: clump %u, node_size %zu\n",
+ clump_size, node_size);
+
+ /* The end of the node contains list of record offsets */
+ rec_offsets = (__be16 *)(buf + node_size);
+
+ desc = (struct hfs_bnode_desc *)buf;
+ desc->type = HFS_NODE_HEADER;
+ desc->num_recs = cpu_to_be16(HFSPLUS_BTREE_HDR_NODE_RECS_COUNT);
+ offset = sizeof(struct hfs_bnode_desc);
+ *--rec_offsets = cpu_to_be16(offset);
+
+ head = (struct hfs_btree_header_rec *)(buf + offset);
+ head->node_size = cpu_to_be16(node_size);
+ head->node_count = cpu_to_be32(i_size_read(attr_file) / node_size);
+ head->free_nodes = cpu_to_be32(be32_to_cpu(head->node_count) - 1);
+ head->clump_size = cpu_to_be32(clump_size);
+ head->attributes |= cpu_to_be32(HFS_TREE_BIGKEYS | HFS_TREE_VARIDXKEYS);
+ head->max_key_len = cpu_to_be16(HFSPLUS_ATTR_KEYLEN - sizeof(u16));
+ offset += sizeof(struct hfs_btree_header_rec);
+ *--rec_offsets = cpu_to_be16(offset);
+ offset += HFSPLUS_BTREE_HDR_USER_BYTES;
+ *--rec_offsets = cpu_to_be16(offset);
+
+ hdr_node_map_rec_bits = 8 * (node_size - offset - (4 * sizeof(u16)));
+ if (be32_to_cpu(head->node_count) > hdr_node_map_rec_bits) {
+ u32 map_node_bits;
+ u32 map_nodes;
+
+ desc->next = cpu_to_be32(be32_to_cpu(head->leaf_tail) + 1);
+ map_node_bits = 8 * (node_size - sizeof(struct hfs_bnode_desc) -
+ (2 * sizeof(u16)) - 2);
+ map_nodes = (be32_to_cpu(head->node_count) -
+ hdr_node_map_rec_bits +
+ (map_node_bits - 1)) / map_node_bits;
+ be32_add_cpu(&head->free_nodes, 0 - map_nodes);
+ }
+
+ bmp = buf + offset;
+ used_nodes =
+ be32_to_cpu(head->node_count) - be32_to_cpu(head->free_nodes);
+ used_bmp_bytes = used_nodes / 8;
+ if (used_bmp_bytes) {
+ memset(bmp, 0xFF, used_bmp_bytes);
+ bmp += used_bmp_bytes;
+ used_nodes %= 8;
+ }
+ *bmp = ~(0xFF >> used_nodes);
+ offset += hdr_node_map_rec_bits / 8;
+ *--rec_offsets = cpu_to_be16(offset);
+}
+
int __hfsplus_setxattr(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{