1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #ifndef __DIR_DOT_H__
11 #define __DIR_DOT_H__
12 
13 #include <linux/dcache.h>
14 #include <linux/crc32.h>
15 
16 struct inode;
17 struct gfs2_inode;
18 struct gfs2_inum;
19 
20 extern struct inode *gfs2_dir_search(struct inode *dir,
21 				     const struct qstr *filename);
22 extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
23 			  const struct gfs2_inode *ip);
24 extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,
25 			const struct gfs2_inode *ip, unsigned int type);
26 extern int gfs2_dir_del(struct gfs2_inode *dip, const struct qstr *filename);
27 extern int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
28 			 filldir_t filldir);
29 extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
30 			  const struct gfs2_inode *nip, unsigned int new_type);
31 
32 extern int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
33 
34 extern int gfs2_diradd_alloc_required(struct inode *dir,
35 				      const struct qstr *filename);
36 extern int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
37 				   struct buffer_head **bhp);
38 
gfs2_disk_hash(const char * data,int len)39 static inline u32 gfs2_disk_hash(const char *data, int len)
40 {
41         return crc32_le((u32)~0, data, len) ^ (u32)~0;
42 }
43 
44 
gfs2_str2qstr(struct qstr * name,const char * fname)45 static inline void gfs2_str2qstr(struct qstr *name, const char *fname)
46 {
47 	name->name = fname;
48 	name->len = strlen(fname);
49 	name->hash = gfs2_disk_hash(name->name, name->len);
50 }
51 
52 /* N.B. This probably ought to take inum & type as args as well */
gfs2_qstr2dirent(const struct qstr * name,u16 reclen,struct gfs2_dirent * dent)53 static inline void gfs2_qstr2dirent(const struct qstr *name, u16 reclen, struct gfs2_dirent *dent)
54 {
55 	dent->de_inum.no_addr = cpu_to_be64(0);
56 	dent->de_inum.no_formal_ino = cpu_to_be64(0);
57 	dent->de_hash = cpu_to_be32(name->hash);
58 	dent->de_rec_len = cpu_to_be16(reclen);
59 	dent->de_name_len = cpu_to_be16(name->len);
60 	dent->de_type = cpu_to_be16(0);
61 	memset(dent->__pad, 0, sizeof(dent->__pad));
62 	memcpy(dent + 1, name->name, name->len);
63 }
64 
65 extern struct qstr gfs2_qdot;
66 extern struct qstr gfs2_qdotdot;
67 
68 #endif /* __DIR_DOT_H__ */
69