xref: /openbmc/linux/fs/coda/inode.c (revision 160b8e75) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Super block/filesystem wide operations
4  *
5  * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
6  * Michael Callahan <callahan@maths.ox.ac.uk>
7  *
8  * Rewritten for Linux 2.1.  Peter Braam <braam@cs.cmu.edu>
9  * Copyright (C) Carnegie Mellon University
10  */
11 
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/string.h>
16 #include <linux/stat.h>
17 #include <linux/errno.h>
18 #include <linux/unistd.h>
19 #include <linux/mutex.h>
20 #include <linux/spinlock.h>
21 #include <linux/file.h>
22 #include <linux/vfs.h>
23 #include <linux/slab.h>
24 #include <linux/pid_namespace.h>
25 #include <linux/uaccess.h>
26 #include <linux/fs.h>
27 #include <linux/vmalloc.h>
28 
29 #include <linux/coda.h>
30 #include <linux/coda_psdev.h>
31 #include "coda_linux.h"
32 #include "coda_cache.h"
33 
34 #include "coda_int.h"
35 
36 /* VFS super_block ops */
37 static void coda_evict_inode(struct inode *);
38 static void coda_put_super(struct super_block *);
39 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
40 
41 static struct kmem_cache * coda_inode_cachep;
42 
43 static struct inode *coda_alloc_inode(struct super_block *sb)
44 {
45 	struct coda_inode_info *ei;
46 	ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
47 	if (!ei)
48 		return NULL;
49 	memset(&ei->c_fid, 0, sizeof(struct CodaFid));
50 	ei->c_flags = 0;
51 	ei->c_uid = GLOBAL_ROOT_UID;
52 	ei->c_cached_perm = 0;
53 	spin_lock_init(&ei->c_lock);
54 	return &ei->vfs_inode;
55 }
56 
57 static void coda_i_callback(struct rcu_head *head)
58 {
59 	struct inode *inode = container_of(head, struct inode, i_rcu);
60 	kmem_cache_free(coda_inode_cachep, ITOC(inode));
61 }
62 
63 static void coda_destroy_inode(struct inode *inode)
64 {
65 	call_rcu(&inode->i_rcu, coda_i_callback);
66 }
67 
68 static void init_once(void *foo)
69 {
70 	struct coda_inode_info *ei = (struct coda_inode_info *) foo;
71 
72 	inode_init_once(&ei->vfs_inode);
73 }
74 
75 int __init coda_init_inodecache(void)
76 {
77 	coda_inode_cachep = kmem_cache_create("coda_inode_cache",
78 				sizeof(struct coda_inode_info), 0,
79 				SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
80 				SLAB_ACCOUNT, init_once);
81 	if (coda_inode_cachep == NULL)
82 		return -ENOMEM;
83 	return 0;
84 }
85 
86 void coda_destroy_inodecache(void)
87 {
88 	/*
89 	 * Make sure all delayed rcu free inodes are flushed before we
90 	 * destroy cache.
91 	 */
92 	rcu_barrier();
93 	kmem_cache_destroy(coda_inode_cachep);
94 }
95 
96 static int coda_remount(struct super_block *sb, int *flags, char *data)
97 {
98 	sync_filesystem(sb);
99 	*flags |= SB_NOATIME;
100 	return 0;
101 }
102 
103 /* exported operations */
104 static const struct super_operations coda_super_operations =
105 {
106 	.alloc_inode	= coda_alloc_inode,
107 	.destroy_inode	= coda_destroy_inode,
108 	.evict_inode	= coda_evict_inode,
109 	.put_super	= coda_put_super,
110 	.statfs		= coda_statfs,
111 	.remount_fs	= coda_remount,
112 };
113 
114 static int get_device_index(struct coda_mount_data *data)
115 {
116 	struct fd f;
117 	struct inode *inode;
118 	int idx;
119 
120 	if (data == NULL) {
121 		pr_warn("%s: Bad mount data\n", __func__);
122 		return -1;
123 	}
124 
125 	if (data->version != CODA_MOUNT_VERSION) {
126 		pr_warn("%s: Bad mount version\n", __func__);
127 		return -1;
128 	}
129 
130 	f = fdget(data->fd);
131 	if (!f.file)
132 		goto Ebadf;
133 	inode = file_inode(f.file);
134 	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
135 		fdput(f);
136 		goto Ebadf;
137 	}
138 
139 	idx = iminor(inode);
140 	fdput(f);
141 
142 	if (idx < 0 || idx >= MAX_CODADEVS) {
143 		pr_warn("%s: Bad minor number\n", __func__);
144 		return -1;
145 	}
146 
147 	return idx;
148 Ebadf:
149 	pr_warn("%s: Bad file\n", __func__);
150 	return -1;
151 }
152 
153 static int coda_fill_super(struct super_block *sb, void *data, int silent)
154 {
155 	struct inode *root = NULL;
156 	struct venus_comm *vc;
157 	struct CodaFid fid;
158 	int error;
159 	int idx;
160 
161 	if (task_active_pid_ns(current) != &init_pid_ns)
162 		return -EINVAL;
163 
164 	idx = get_device_index((struct coda_mount_data *) data);
165 
166 	/* Ignore errors in data, for backward compatibility */
167 	if(idx == -1)
168 		idx = 0;
169 
170 	pr_info("%s: device index: %i\n", __func__,  idx);
171 
172 	vc = &coda_comms[idx];
173 	mutex_lock(&vc->vc_mutex);
174 
175 	if (!vc->vc_inuse) {
176 		pr_warn("%s: No pseudo device\n", __func__);
177 		error = -EINVAL;
178 		goto unlock_out;
179 	}
180 
181 	if (vc->vc_sb) {
182 		pr_warn("%s: Device already mounted\n", __func__);
183 		error = -EBUSY;
184 		goto unlock_out;
185 	}
186 
187 	vc->vc_sb = sb;
188 	mutex_unlock(&vc->vc_mutex);
189 
190 	sb->s_fs_info = vc;
191 	sb->s_flags |= SB_NOATIME;
192 	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
193 	sb->s_blocksize_bits = 12;
194 	sb->s_magic = CODA_SUPER_MAGIC;
195 	sb->s_op = &coda_super_operations;
196 	sb->s_d_op = &coda_dentry_operations;
197 
198 	error = super_setup_bdi(sb);
199 	if (error)
200 		goto error;
201 
202 	/* get root fid from Venus: this needs the root inode */
203 	error = venus_rootfid(sb, &fid);
204 	if ( error ) {
205 		pr_warn("%s: coda_get_rootfid failed with %d\n",
206 			__func__, error);
207 		goto error;
208 	}
209 	pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
210 
211 	/* make root inode */
212         root = coda_cnode_make(&fid, sb);
213         if (IS_ERR(root)) {
214 		error = PTR_ERR(root);
215 		pr_warn("Failure of coda_cnode_make for root: error %d\n",
216 			error);
217 		goto error;
218 	}
219 
220 	pr_info("%s: rootinode is %ld dev %s\n",
221 		__func__, root->i_ino, root->i_sb->s_id);
222 	sb->s_root = d_make_root(root);
223 	if (!sb->s_root) {
224 		error = -EINVAL;
225 		goto error;
226 	}
227 	return 0;
228 
229 error:
230 	mutex_lock(&vc->vc_mutex);
231 	vc->vc_sb = NULL;
232 	sb->s_fs_info = NULL;
233 unlock_out:
234 	mutex_unlock(&vc->vc_mutex);
235 	return error;
236 }
237 
238 static void coda_put_super(struct super_block *sb)
239 {
240 	struct venus_comm *vcp = coda_vcp(sb);
241 	mutex_lock(&vcp->vc_mutex);
242 	vcp->vc_sb = NULL;
243 	sb->s_fs_info = NULL;
244 	mutex_unlock(&vcp->vc_mutex);
245 
246 	pr_info("Bye bye.\n");
247 }
248 
249 static void coda_evict_inode(struct inode *inode)
250 {
251 	truncate_inode_pages_final(&inode->i_data);
252 	clear_inode(inode);
253 	coda_cache_clear_inode(inode);
254 }
255 
256 int coda_getattr(const struct path *path, struct kstat *stat,
257 		 u32 request_mask, unsigned int flags)
258 {
259 	int err = coda_revalidate_inode(d_inode(path->dentry));
260 	if (!err)
261 		generic_fillattr(d_inode(path->dentry), stat);
262 	return err;
263 }
264 
265 int coda_setattr(struct dentry *de, struct iattr *iattr)
266 {
267 	struct inode *inode = d_inode(de);
268 	struct coda_vattr vattr;
269 	int error;
270 
271 	memset(&vattr, 0, sizeof(vattr));
272 
273 	inode->i_ctime = current_time(inode);
274 	coda_iattr_to_vattr(iattr, &vattr);
275 	vattr.va_type = C_VNON; /* cannot set type */
276 
277 	/* Venus is responsible for truncating the container-file!!! */
278 	error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
279 
280 	if (!error) {
281 	        coda_vattr_to_iattr(inode, &vattr);
282 		coda_cache_clear_inode(inode);
283 	}
284 	return error;
285 }
286 
287 const struct inode_operations coda_file_inode_operations = {
288 	.permission	= coda_permission,
289 	.getattr	= coda_getattr,
290 	.setattr	= coda_setattr,
291 };
292 
293 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
294 {
295 	int error;
296 
297 	error = venus_statfs(dentry, buf);
298 
299 	if (error) {
300 		/* fake something like AFS does */
301 		buf->f_blocks = 9000000;
302 		buf->f_bfree  = 9000000;
303 		buf->f_bavail = 9000000;
304 		buf->f_files  = 9000000;
305 		buf->f_ffree  = 9000000;
306 	}
307 
308 	/* and fill in the rest */
309 	buf->f_type = CODA_SUPER_MAGIC;
310 	buf->f_bsize = 4096;
311 	buf->f_namelen = CODA_MAXNAMLEN;
312 
313 	return 0;
314 }
315 
316 /* init_coda: used by filesystems.c to register coda */
317 
318 static struct dentry *coda_mount(struct file_system_type *fs_type,
319 	int flags, const char *dev_name, void *data)
320 {
321 	return mount_nodev(fs_type, flags, data, coda_fill_super);
322 }
323 
324 struct file_system_type coda_fs_type = {
325 	.owner		= THIS_MODULE,
326 	.name		= "coda",
327 	.mount		= coda_mount,
328 	.kill_sb	= kill_anon_super,
329 	.fs_flags	= FS_BINARY_MOUNTDATA,
330 };
331 MODULE_ALIAS_FS("coda");
332 
333