File: cache.c

package info (click to toggle)
linux 4.19.37-3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 962,264 kB
  • sloc: ansic: 16,757,120; asm: 271,404; makefile: 38,285; sh: 33,529; perl: 27,681; python: 21,031; cpp: 5,063; yacc: 4,648; lex: 2,585; awk: 1,385; ruby: 25; sed: 5
file content (146 lines) | stat: -rw-r--r-- 3,866 bytes parent folder | download | duplicates (13)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
 *   fs/cifs/cache.c - CIFS filesystem cache index structure definitions
 *
 *   Copyright (c) 2010 Novell, Inc.
 *   Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include "fscache.h"
#include "cifs_debug.h"

/*
 * CIFS filesystem definition for FS-Cache
 */
struct fscache_netfs cifs_fscache_netfs = {
	.name = "cifs",
	.version = 0,
};

/*
 * Register CIFS for caching with FS-Cache
 */
int cifs_fscache_register(void)
{
	return fscache_register_netfs(&cifs_fscache_netfs);
}

/*
 * Unregister CIFS for caching
 */
void cifs_fscache_unregister(void)
{
	fscache_unregister_netfs(&cifs_fscache_netfs);
}

/*
 * Server object for FS-Cache
 */
const struct fscache_cookie_def cifs_fscache_server_index_def = {
	.name = "CIFS.server",
	.type = FSCACHE_COOKIE_TYPE_INDEX,
};

/*
 * Auxiliary data attached to CIFS superblock within the cache
 */
struct cifs_fscache_super_auxdata {
	u64	resource_id;		/* unique server resource id */
};

char *extract_sharename(const char *treename)
{
	const char *src;
	char *delim, *dst;
	int len;

	/* skip double chars at the beginning */
	src = treename + 2;

	/* share name is always preceded by '\\' now */
	delim = strchr(src, '\\');
	if (!delim)
		return ERR_PTR(-EINVAL);
	delim++;
	len = strlen(delim);

	/* caller has to free the memory */
	dst = kstrndup(delim, len, GFP_KERNEL);
	if (!dst)
		return ERR_PTR(-ENOMEM);

	return dst;
}

static enum
fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
					      const void *data,
					      uint16_t datalen,
					      loff_t object_size)
{
	struct cifs_fscache_super_auxdata auxdata;
	const struct cifs_tcon *tcon = cookie_netfs_data;

	if (datalen != sizeof(auxdata))
		return FSCACHE_CHECKAUX_OBSOLETE;

	memset(&auxdata, 0, sizeof(auxdata));
	auxdata.resource_id = tcon->resource_id;

	if (memcmp(data, &auxdata, datalen) != 0)
		return FSCACHE_CHECKAUX_OBSOLETE;

	return FSCACHE_CHECKAUX_OKAY;
}

/*
 * Superblock object for FS-Cache
 */
const struct fscache_cookie_def cifs_fscache_super_index_def = {
	.name = "CIFS.super",
	.type = FSCACHE_COOKIE_TYPE_INDEX,
	.check_aux = cifs_fscache_super_check_aux,
};

static enum
fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
					      const void *data,
					      uint16_t datalen,
					      loff_t object_size)
{
	struct cifs_fscache_inode_auxdata auxdata;
	struct cifsInodeInfo *cifsi = cookie_netfs_data;

	if (datalen != sizeof(auxdata))
		return FSCACHE_CHECKAUX_OBSOLETE;

	memset(&auxdata, 0, sizeof(auxdata));
	auxdata.eof = cifsi->server_eof;
	auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
	auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
	auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
	auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;

	if (memcmp(data, &auxdata, datalen) != 0)
		return FSCACHE_CHECKAUX_OBSOLETE;

	return FSCACHE_CHECKAUX_OKAY;
}

const struct fscache_cookie_def cifs_fscache_inode_object_def = {
	.name		= "CIFS.uniqueid",
	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
	.check_aux	= cifs_fscache_inode_check_aux,
};