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
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 */
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
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
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
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 umode_t inode_type = coda_inode_type(attr);
67
68 retry:
69 inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
70 if (!inode)
71 return ERR_PTR(-ENOMEM);
72
73 if (inode->i_state & I_NEW) {
74 cii = ITOC(inode);
75 /* we still need to set i_ino for things like stat(2) */
76 inode->i_ino = hash;
77 /* inode is locked and unique, no need to grab cii->c_lock */
78 cii->c_mapcount = 0;
79 coda_fill_inode(inode, attr);
80 unlock_new_inode(inode);
81 } else if ((inode->i_mode & S_IFMT) != inode_type) {
82 /* Inode has changed type, mark bad and grab a new one */
83 remove_inode_hash(inode);
84 coda_flag_inode(inode, C_PURGE);
85 iput(inode);
86 goto retry;
87 }
88 return inode;
89 }
90
91 /* this is effectively coda_iget:
92 - get attributes (might be cached)
93 - get the inode for the fid using vfs iget
94 - link the two up if this is needed
95 - fill in the attributes
96 */
97 struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb)
98 {
99 struct coda_vattr attr;
100 struct inode *inode;
101 int error;
102
103 /* We get inode numbers from Venus -- see venus source */
104 error = venus_getattr(sb, fid, &attr);
105 if (error)
106 return ERR_PTR(error);
107
108 inode = coda_iget(sb, fid, &attr);
109 if (IS_ERR(inode))
110 pr_warn("%s: coda_iget failed\n", __func__);
111 return inode;
112 }
113
114
115 /* Although we treat Coda file identifiers as immutable, there is one
116 * special case for files created during a disconnection where they may
117 * not be globally unique. When an identifier collision is detected we
118 * first try to flush the cached inode from the kernel and finally
119 * resort to renaming/rehashing in-place. Userspace remembers both old
120 * and new values of the identifier to handle any in-flight upcalls.
121 * The real solution is to use globally unique UUIDs as identifiers, but
122 * retrofitting the existing userspace code for this is non-trivial. */
123 void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid,
124 struct CodaFid *newfid)
125 {
126 struct coda_inode_info *cii = ITOC(inode);
127 unsigned long hash = coda_f2i(newfid);
128
129 BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
130
131 /* replace fid and rehash inode */
132 /* XXX we probably need to hold some lock here! */
133 remove_inode_hash(inode);
134 cii->c_fid = *newfid;
135 inode->i_ino = hash;
136 __insert_inode_hash(inode, hash);
137 }
138
139 /* convert a fid to an inode. */
140 struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb)
141 {
142 struct inode *inode;
143 unsigned long hash = coda_f2i(fid);
144
145 inode = ilookup5(sb, hash, coda_test_inode, fid);
146 if ( !inode )
147 return NULL;
148
149 /* we should never see newly created inodes because we intentionally
150 * fail in the initialization callback */
151 BUG_ON(inode->i_state & I_NEW);
152
153 return inode;
154 }
155
156 struct coda_file_info *coda_ftoc(struct file *file)
157 {
158 struct coda_file_info *cfi = file->private_data;
159
160 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
161
162 return cfi;
163
164 }
165
166 /* the CONTROL inode is made without asking attributes from Venus */
167 struct inode *coda_cnode_makectl(struct super_block *sb)
168 {
169 struct inode *inode = new_inode(sb);
170 if (inode) {
171 inode->i_ino = CTL_INO;
172 inode->i_op = &coda_ioctl_inode_operations;
173 inode->i_fop = &coda_ioctl_operations;
174 inode->i_mode = 0444;
175 return inode;
176 }
177 return ERR_PTR(-ENOMEM);
178 }
179
180
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