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(p: fid1, q: fid2, size: 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(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(fid1: &cii->c_fid, fid2: 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, test: coda_test_inode, set: coda_set_inode, fid); |
70 | if (!inode) |
71 | return ERR_PTR(error: -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: &attr); |
105 | if (error) |
106 | return ERR_PTR(error); |
107 | |
108 | inode = coda_iget(sb, fid, attr: &attr); |
109 | if (IS_ERR(ptr: 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, hashval: 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, hashval: hash, test: coda_test_inode, data: 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(error: -ENOMEM); |
178 | } |
179 | |
180 | |