1 /* cnode related routines for the coda kernel code
2 (C) 1996 Peter Braam
3 */
4
5 #include <linux/types.h>
6 #include <linux/string.h>
7 #include <linux/time.h>
8
9 #include <linux/coda.h>
10 #include <linux/coda_psdev.h>
11 #include "coda_linux.h"
12
coda_fideq(struct CodaFid * fid1,struct CodaFid * fid2)13 static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
14 {
15 return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
16 }
17
18 static const struct inode_operations coda_symlink_inode_operations = {
19 .readlink = generic_readlink,
20 .follow_link = page_follow_link_light,
21 .put_link = page_put_link,
22 .setattr = coda_setattr,
23 };
24
25 /* cnode.c */
coda_fill_inode(struct inode * inode,struct coda_vattr * attr)26 static void coda_fill_inode(struct inode *inode, struct coda_vattr *attr)
27 {
28 coda_vattr_to_iattr(inode, attr);
29
30 if (S_ISREG(inode->i_mode)) {
31 inode->i_op = &coda_file_inode_operations;
32 inode->i_fop = &coda_file_operations;
33 } else if (S_ISDIR(inode->i_mode)) {
34 inode->i_op = &coda_dir_inode_operations;
35 inode->i_fop = &coda_dir_operations;
36 } else if (S_ISLNK(inode->i_mode)) {
37 inode->i_op = &coda_symlink_inode_operations;
38 inode->i_data.a_ops = &coda_symlink_aops;
39 inode->i_mapping = &inode->i_data;
40 } else
41 init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
42 }
43
coda_test_inode(struct inode * inode,void * data)44 static int coda_test_inode(struct inode *inode, void *data)
45 {
46 struct CodaFid *fid = (struct CodaFid *)data;
47 struct coda_inode_info *cii = ITOC(inode);
48 return coda_fideq(&cii->c_fid, fid);
49 }
50
coda_set_inode(struct inode * inode,void * data)51 static int coda_set_inode(struct inode *inode, void *data)
52 {
53 struct CodaFid *fid = (struct CodaFid *)data;
54 struct coda_inode_info *cii = ITOC(inode);
55 cii->c_fid = *fid;
56 return 0;
57 }
58
coda_iget(struct super_block * sb,struct CodaFid * fid,struct coda_vattr * attr)59 struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
60 struct coda_vattr * attr)
61 {
62 struct inode *inode;
63 struct coda_inode_info *cii;
64 unsigned long hash = coda_f2i(fid);
65
66 inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
67
68 if (!inode)
69 return ERR_PTR(-ENOMEM);
70
71 if (inode->i_state & I_NEW) {
72 cii = ITOC(inode);
73 /* we still need to set i_ino for things like stat(2) */
74 inode->i_ino = hash;
75 /* inode is locked and unique, no need to grab cii->c_lock */
76 cii->c_mapcount = 0;
77 unlock_new_inode(inode);
78 }
79
80 /* always replace the attributes, type might have changed */
81 coda_fill_inode(inode, attr);
82 return inode;
83 }
84
85 /* this is effectively coda_iget:
86 - get attributes (might be cached)
87 - get the inode for the fid using vfs iget
88 - link the two up if this is needed
89 - fill in the attributes
90 */
coda_cnode_make(struct CodaFid * fid,struct super_block * sb)91 struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb)
92 {
93 struct coda_vattr attr;
94 struct inode *inode;
95 int error;
96
97 /* We get inode numbers from Venus -- see venus source */
98 error = venus_getattr(sb, fid, &attr);
99 if (error)
100 return ERR_PTR(error);
101
102 inode = coda_iget(sb, fid, &attr);
103 if (IS_ERR(inode))
104 printk("coda_cnode_make: coda_iget failed\n");
105 return inode;
106 }
107
108
109 /* Although we treat Coda file identifiers as immutable, there is one
110 * special case for files created during a disconnection where they may
111 * not be globally unique. When an identifier collision is detected we
112 * first try to flush the cached inode from the kernel and finally
113 * resort to renaming/rehashing in-place. Userspace remembers both old
114 * and new values of the identifier to handle any in-flight upcalls.
115 * The real solution is to use globally unique UUIDs as identifiers, but
116 * retrofitting the existing userspace code for this is non-trivial. */
coda_replace_fid(struct inode * inode,struct CodaFid * oldfid,struct CodaFid * newfid)117 void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid,
118 struct CodaFid *newfid)
119 {
120 struct coda_inode_info *cii = ITOC(inode);
121 unsigned long hash = coda_f2i(newfid);
122
123 BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
124
125 /* replace fid and rehash inode */
126 /* XXX we probably need to hold some lock here! */
127 remove_inode_hash(inode);
128 cii->c_fid = *newfid;
129 inode->i_ino = hash;
130 __insert_inode_hash(inode, hash);
131 }
132
133 /* convert a fid to an inode. */
coda_fid_to_inode(struct CodaFid * fid,struct super_block * sb)134 struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb)
135 {
136 struct inode *inode;
137 unsigned long hash = coda_f2i(fid);
138
139 if ( !sb ) {
140 printk("coda_fid_to_inode: no sb!\n");
141 return NULL;
142 }
143
144 inode = ilookup5(sb, hash, coda_test_inode, fid);
145 if ( !inode )
146 return NULL;
147
148 /* we should never see newly created inodes because we intentionally
149 * fail in the initialization callback */
150 BUG_ON(inode->i_state & I_NEW);
151
152 return inode;
153 }
154
155 /* the CONTROL inode is made without asking attributes from Venus */
coda_cnode_makectl(struct super_block * sb)156 struct inode *coda_cnode_makectl(struct super_block *sb)
157 {
158 struct inode *inode = new_inode(sb);
159 if (inode) {
160 inode->i_ino = CTL_INO;
161 inode->i_op = &coda_ioctl_inode_operations;
162 inode->i_fop = &coda_ioctl_operations;
163 inode->i_mode = 0444;
164 return inode;
165 }
166 return ERR_PTR(-ENOMEM);
167 }
168
169