1 // SPDX-License-Identifier: GPL-2.0
2 /* cnode related routines for the coda kernel code
3 (C) 1996 Peter Braam
4 */
5
6 #include <linux/types.h>
7 #include <linux/string.h>
8 #include <linux/time.h>
9
10 #include <linux/coda.h>
11 #include <linux/pagemap.h>
12 #include "coda_psdev.h"
13 #include "coda_linux.h"
14
coda_fideq(struct CodaFid * fid1,struct CodaFid * fid2)15 static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
16 {
17 return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
18 }
19
20 static const struct inode_operations coda_symlink_inode_operations = {
21 .get_link = page_get_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_nohighmem(inode);
39 inode->i_data.a_ops = &coda_symlink_aops;
40 inode->i_mapping = &inode->i_data;
41 } else
42 init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
43 }
44
coda_test_inode(struct inode * inode,void * data)45 static int coda_test_inode(struct inode *inode, void *data)
46 {
47 struct CodaFid *fid = (struct CodaFid *)data;
48 struct coda_inode_info *cii = ITOC(inode);
49 return coda_fideq(&cii->c_fid, fid);
50 }
51
coda_set_inode(struct inode * inode,void * data)52 static int coda_set_inode(struct inode *inode, void *data)
53 {
54 struct CodaFid *fid = (struct CodaFid *)data;
55 struct coda_inode_info *cii = ITOC(inode);
56 cii->c_fid = *fid;
57 return 0;
58 }
59
coda_iget(struct super_block * sb,struct CodaFid * fid,struct coda_vattr * attr)60 struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
61 struct coda_vattr * attr)
62 {
63 struct inode *inode;
64 struct coda_inode_info *cii;
65 unsigned long hash = coda_f2i(fid);
66
67 inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
68
69 if (!inode)
70 return ERR_PTR(-ENOMEM);
71
72 if (inode->i_state & I_NEW) {
73 cii = ITOC(inode);
74 /* we still need to set i_ino for things like stat(2) */
75 inode->i_ino = hash;
76 /* inode is locked and unique, no need to grab cii->c_lock */
77 cii->c_mapcount = 0;
78 unlock_new_inode(inode);
79 }
80
81 /* always replace the attributes, type might have changed */
82 coda_fill_inode(inode, attr);
83 return inode;
84 }
85
86 /* this is effectively coda_iget:
87 - get attributes (might be cached)
88 - get the inode for the fid using vfs iget
89 - link the two up if this is needed
90 - fill in the attributes
91 */
coda_cnode_make(struct CodaFid * fid,struct super_block * sb)92 struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb)
93 {
94 struct coda_vattr attr;
95 struct inode *inode;
96 int error;
97
98 /* We get inode numbers from Venus -- see venus source */
99 error = venus_getattr(sb, fid, &attr);
100 if (error)
101 return ERR_PTR(error);
102
103 inode = coda_iget(sb, fid, &attr);
104 if (IS_ERR(inode))
105 pr_warn("%s: coda_iget failed\n", __func__);
106 return inode;
107 }
108
109
110 /* Although we treat Coda file identifiers as immutable, there is one
111 * special case for files created during a disconnection where they may
112 * not be globally unique. When an identifier collision is detected we
113 * first try to flush the cached inode from the kernel and finally
114 * resort to renaming/rehashing in-place. Userspace remembers both old
115 * and new values of the identifier to handle any in-flight upcalls.
116 * The real solution is to use globally unique UUIDs as identifiers, but
117 * retrofitting the existing userspace code for this is non-trivial. */
coda_replace_fid(struct inode * inode,struct CodaFid * oldfid,struct CodaFid * newfid)118 void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid,
119 struct CodaFid *newfid)
120 {
121 struct coda_inode_info *cii = ITOC(inode);
122 unsigned long hash = coda_f2i(newfid);
123
124 BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
125
126 /* replace fid and rehash inode */
127 /* XXX we probably need to hold some lock here! */
128 remove_inode_hash(inode);
129 cii->c_fid = *newfid;
130 inode->i_ino = hash;
131 __insert_inode_hash(inode, hash);
132 }
133
134 /* convert a fid to an inode. */
coda_fid_to_inode(struct CodaFid * fid,struct super_block * sb)135 struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb)
136 {
137 struct inode *inode;
138 unsigned long hash = coda_f2i(fid);
139
140 inode = ilookup5(sb, hash, coda_test_inode, fid);
141 if ( !inode )
142 return NULL;
143
144 /* we should never see newly created inodes because we intentionally
145 * fail in the initialization callback */
146 BUG_ON(inode->i_state & I_NEW);
147
148 return inode;
149 }
150
coda_ftoc(struct file * file)151 struct coda_file_info *coda_ftoc(struct file *file)
152 {
153 struct coda_file_info *cfi = file->private_data;
154
155 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
156
157 return cfi;
158
159 }
160
161 /* the CONTROL inode is made without asking attributes from Venus */
coda_cnode_makectl(struct super_block * sb)162 struct inode *coda_cnode_makectl(struct super_block *sb)
163 {
164 struct inode *inode = new_inode(sb);
165 if (inode) {
166 inode->i_ino = CTL_INO;
167 inode->i_op = &coda_ioctl_inode_operations;
168 inode->i_fop = &coda_ioctl_operations;
169 inode->i_mode = 0444;
170 return inode;
171 }
172 return ERR_PTR(-ENOMEM);
173 }
174
175
