xref: /kernel/linux/linux-5.10/fs/coda/cnode.c (revision 8c2ecf20) 
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
15static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
16{
17	return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
18}
19
20static const struct inode_operations coda_symlink_inode_operations = {
21	.get_link	= page_get_link,
22	.setattr	= coda_setattr,
23};
24
25/* cnode.c */
26static 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
45static 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
52static 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
60struct 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*/
92struct 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. */
118void 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. */
135struct 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
151struct 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 */
162struct 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