cnode.c
4.68 KB
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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/* cnode related routines for the coda kernel code
(C) 1996 Peter Braam
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/coda.h>
#include <linux/coda_psdev.h>
#include "coda_linux.h"
static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
{
return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
}
static const struct inode_operations coda_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
.setattr = coda_setattr,
};
/* cnode.c */
static void coda_fill_inode(struct inode *inode, struct coda_vattr *attr)
{
coda_vattr_to_iattr(inode, attr);
if (S_ISREG(inode->i_mode)) {
inode->i_op = &coda_file_inode_operations;
inode->i_fop = &coda_file_operations;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &coda_dir_inode_operations;
inode->i_fop = &coda_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &coda_symlink_inode_operations;
inode->i_data.a_ops = &coda_symlink_aops;
inode->i_mapping = &inode->i_data;
} else
init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
}
static int coda_test_inode(struct inode *inode, void *data)
{
struct CodaFid *fid = (struct CodaFid *)data;
struct coda_inode_info *cii = ITOC(inode);
return coda_fideq(&cii->c_fid, fid);
}
static int coda_set_inode(struct inode *inode, void *data)
{
struct CodaFid *fid = (struct CodaFid *)data;
struct coda_inode_info *cii = ITOC(inode);
cii->c_fid = *fid;
return 0;
}
struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
struct coda_vattr * attr)
{
struct inode *inode;
struct coda_inode_info *cii;
unsigned long hash = coda_f2i(fid);
inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
cii = ITOC(inode);
/* we still need to set i_ino for things like stat(2) */
inode->i_ino = hash;
/* inode is locked and unique, no need to grab cii->c_lock */
cii->c_mapcount = 0;
unlock_new_inode(inode);
}
/* always replace the attributes, type might have changed */
coda_fill_inode(inode, attr);
return inode;
}
/* this is effectively coda_iget:
- get attributes (might be cached)
- get the inode for the fid using vfs iget
- link the two up if this is needed
- fill in the attributes
*/
struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb)
{
struct coda_vattr attr;
struct inode *inode;
int error;
/* We get inode numbers from Venus -- see venus source */
error = venus_getattr(sb, fid, &attr);
if (error)
return ERR_PTR(error);
inode = coda_iget(sb, fid, &attr);
if (IS_ERR(inode))
printk("coda_cnode_make: coda_iget failed\n");
return inode;
}
/* Although we treat Coda file identifiers as immutable, there is one
* special case for files created during a disconnection where they may
* not be globally unique. When an identifier collision is detected we
* first try to flush the cached inode from the kernel and finally
* resort to renaming/rehashing in-place. Userspace remembers both old
* and new values of the identifier to handle any in-flight upcalls.
* The real solution is to use globally unique UUIDs as identifiers, but
* retrofitting the existing userspace code for this is non-trivial. */
void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid,
struct CodaFid *newfid)
{
struct coda_inode_info *cii = ITOC(inode);
unsigned long hash = coda_f2i(newfid);
BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
/* replace fid and rehash inode */
/* XXX we probably need to hold some lock here! */
remove_inode_hash(inode);
cii->c_fid = *newfid;
inode->i_ino = hash;
__insert_inode_hash(inode, hash);
}
/* convert a fid to an inode. */
struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb)
{
struct inode *inode;
unsigned long hash = coda_f2i(fid);
if ( !sb ) {
printk("coda_fid_to_inode: no sb!\n");
return NULL;
}
inode = ilookup5(sb, hash, coda_test_inode, fid);
if ( !inode )
return NULL;
/* we should never see newly created inodes because we intentionally
* fail in the initialization callback */
BUG_ON(inode->i_state & I_NEW);
return inode;
}
/* the CONTROL inode is made without asking attributes from Venus */
struct inode *coda_cnode_makectl(struct super_block *sb)
{
struct inode *inode = new_inode(sb);
if (inode) {
inode->i_ino = CTL_INO;
inode->i_op = &coda_ioctl_inode_operations;
inode->i_fop = &coda_ioctl_operations;
inode->i_mode = 0444;
return inode;
}
return ERR_PTR(-ENOMEM);
}