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/coda_psdev.h>
12 #include <linux/pagemap.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 	if ( !sb ) {
141 		pr_warn("%s: no sb!\n", __func__);
142 		return NULL;
143 	}
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 /* the CONTROL inode is made without asking attributes from Venus */
coda_cnode_makectl(struct super_block * sb)157 struct inode *coda_cnode_makectl(struct super_block *sb)
158 {
159 	struct inode *inode = new_inode(sb);
160 	if (inode) {
161 		inode->i_ino = CTL_INO;
162 		inode->i_op = &coda_ioctl_inode_operations;
163 		inode->i_fop = &coda_ioctl_operations;
164 		inode->i_mode = 0444;
165 		return inode;
166 	}
167 	return ERR_PTR(-ENOMEM);
168 }
169 
170