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 struct buffer_head;
20 struct gfs2_dirent;
21 
22 struct gfs2_diradd {
23 	unsigned nr_blocks;
24 	struct gfs2_dirent *dent;
25 	struct buffer_head *bh;
26 	int save_loc;
27 };
28 
29 extern struct inode *gfs2_dir_search(struct inode *dir,
30 				     const struct qstr *filename,
31 				     bool fail_on_exist);
32 extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
33 			  const struct gfs2_inode *ip);
34 extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,
35 			const struct gfs2_inode *ip, struct gfs2_diradd *da);
gfs2_dir_no_add(struct gfs2_diradd * da)36 static inline void gfs2_dir_no_add(struct gfs2_diradd *da)
37 {
38 	if (da->bh)
39 		brelse(da->bh);
40 	da->bh = NULL;
41 }
42 extern int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry);
43 extern int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
44 			 struct file_ra_state *f_ra);
45 extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
46 			  const struct gfs2_inode *nip, unsigned int new_type);
47 
48 extern int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
49 
50 extern int gfs2_diradd_alloc_required(struct inode *dir,
51 				      const struct qstr *filename,
52 				      struct gfs2_diradd *da);
53 extern int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
54 				   struct buffer_head **bhp);
55 extern void gfs2_dir_hash_inval(struct gfs2_inode *ip);
56 
gfs2_disk_hash(const char * data,int len)57 static inline u32 gfs2_disk_hash(const char *data, int len)
58 {
59         return crc32_le((u32)~0, data, len) ^ (u32)~0;
60 }
61 
62 
gfs2_str2qstr(struct qstr * name,const char * fname)63 static inline void gfs2_str2qstr(struct qstr *name, const char *fname)
64 {
65 	name->name = fname;
66 	name->len = strlen(fname);
67 	name->hash = gfs2_disk_hash(name->name, name->len);
68 }
69 
70 /* 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)71 static inline void gfs2_qstr2dirent(const struct qstr *name, u16 reclen, struct gfs2_dirent *dent)
72 {
73 	dent->de_inum.no_addr = cpu_to_be64(0);
74 	dent->de_inum.no_formal_ino = cpu_to_be64(0);
75 	dent->de_hash = cpu_to_be32(name->hash);
76 	dent->de_rec_len = cpu_to_be16(reclen);
77 	dent->de_name_len = cpu_to_be16(name->len);
78 	dent->de_type = cpu_to_be16(0);
79 	memset(dent->__pad, 0, sizeof(dent->__pad));
80 	memcpy(dent + 1, name->name, name->len);
81 }
82 
83 extern struct qstr gfs2_qdot;
84 extern struct qstr gfs2_qdotdot;
85 
86 #endif /* __DIR_DOT_H__ */
87