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hfsplus: implement attributes file's header node initialization code

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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>
This commit is contained in:
Vyacheslav Dubeyko 2013-11-12 15:11:08 -08:00 committed by Linus Torvalds
parent b3b5b0f03c
commit 099e9245e0
2 changed files with 68 additions and 0 deletions
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3
fs/hfsplus/hfsplus_raw.h
View File

@ -187,6 +187,9 @@ struct hfs_btree_header_rec {
/* HFS+ BTree misc info */
#define HFSPLUS_TREE_HEAD 0
#define HFSPLUS_NODE_MXSZ 32768
#define HFSPLUS_ATTR_TREE_NODE_SIZE 8192
#define HFSPLUS_BTREE_HDR_NODE_RECS_COUNT 3
#define HFSPLUS_BTREE_HDR_USER_BYTES 128
/* Some special File ID numbers (stolen from hfs.h) */
#define HFSPLUS_POR_CNID 1 /* Parent Of the Root */

65
fs/hfsplus/xattr.c
View File

@ -127,6 +127,71 @@ static int can_set_xattr(struct inode *inode, const char *name,
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)
{