xref: /linux/fs/coda/inode.c (revision 06a130e42a5bfc84795464bff023bff4c16f58c5) 
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/fs_context.h>
28 #include <linux/fs_parser.h>
29 #include <linux/vmalloc.h>
30 
31 #include <linux/coda.h>
32 #include "coda_psdev.h"
33 #include "coda_linux.h"
34 #include "coda_cache.h"
35 
36 #include "coda_int.h"
37 
38 /* VFS super_block ops */
39 static void coda_evict_inode(struct inode *);
40 static void coda_put_super(struct super_block *);
41 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
42 
43 static struct kmem_cache * coda_inode_cachep;
44 
45 static struct inode *coda_alloc_inode(struct super_block *sb)
46 {
47 	struct coda_inode_info *ei;
48 	ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL);
49 	if (!ei)
50 		return NULL;
51 	memset(&ei->c_fid, 0, sizeof(struct CodaFid));
52 	ei->c_flags = 0;
53 	ei->c_uid = GLOBAL_ROOT_UID;
54 	ei->c_cached_perm = 0;
55 	spin_lock_init(&ei->c_lock);
56 	return &ei->vfs_inode;
57 }
58 
59 static void coda_free_inode(struct inode *inode)
60 {
61 	kmem_cache_free(coda_inode_cachep, ITOC(inode));
62 }
63 
64 static void init_once(void *foo)
65 {
66 	struct coda_inode_info *ei = (struct coda_inode_info *) foo;
67 
68 	inode_init_once(&ei->vfs_inode);
69 }
70 
71 int __init coda_init_inodecache(void)
72 {
73 	coda_inode_cachep = kmem_cache_create("coda_inode_cache",
74 				sizeof(struct coda_inode_info), 0,
75 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
76 				init_once);
77 	if (coda_inode_cachep == NULL)
78 		return -ENOMEM;
79 	return 0;
80 }
81 
82 void coda_destroy_inodecache(void)
83 {
84 	/*
85 	 * Make sure all delayed rcu free inodes are flushed before we
86 	 * destroy cache.
87 	 */
88 	rcu_barrier();
89 	kmem_cache_destroy(coda_inode_cachep);
90 }
91 
92 static int coda_reconfigure(struct fs_context *fc)
93 {
94 	sync_filesystem(fc->root->d_sb);
95 	fc->sb_flags |= SB_NOATIME;
96 	return 0;
97 }
98 
99 /* exported operations */
100 static const struct super_operations coda_super_operations =
101 {
102 	.alloc_inode	= coda_alloc_inode,
103 	.free_inode	= coda_free_inode,
104 	.evict_inode	= coda_evict_inode,
105 	.put_super	= coda_put_super,
106 	.statfs		= coda_statfs,
107 };
108 
109 struct coda_fs_context {
110 	int	idx;
111 };
112 
113 enum {
114 	Opt_fd,
115 };
116 
117 static const struct fs_parameter_spec coda_param_specs[] = {
118 	fsparam_fd	("fd",	Opt_fd),
119 	{}
120 };
121 
122 static int coda_set_idx(struct fs_context *fc, struct file *file)
123 {
124 	struct coda_fs_context *ctx = fc->fs_private;
125 	struct inode *inode;
126 	int idx;
127 
128 	inode = file_inode(file);
129 	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
130 		return invalf(fc, "coda: Not coda psdev");
131 	}
132 	idx = iminor(inode);
133 	if (idx < 0 || idx >= MAX_CODADEVS)
134 		return invalf(fc, "coda: Bad minor number");
135 	ctx->idx = idx;
136 	return 0;
137 }
138 
139 static int coda_parse_fd(struct fs_context *fc, struct fs_parameter *param,
140 			 struct fs_parse_result *result)
141 {
142 	struct file *file;
143 	int err;
144 
145 	if (param->type == fs_value_is_file) {
146 		file = param->file;
147 		param->file = NULL;
148 	} else {
149 		file = fget(result->uint_32);
150 	}
151 	if (!file)
152 		return -EBADF;
153 
154 	err = coda_set_idx(fc, file);
155 	fput(file);
156 	return err;
157 }
158 
159 static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param)
160 {
161 	struct fs_parse_result result;
162 	int opt;
163 
164 	opt = fs_parse(fc, coda_param_specs, param, &result);
165 	if (opt < 0)
166 		return opt;
167 
168 	switch (opt) {
169 	case Opt_fd:
170 		return coda_parse_fd(fc, param, &result);
171 	}
172 
173 	return 0;
174 }
175 
176 /*
177  * Parse coda's binary mount data form.  We ignore any errors and go with index
178  * 0 if we get one for backward compatibility.
179  */
180 static int coda_parse_monolithic(struct fs_context *fc, void *_data)
181 {
182 	struct file *file;
183 	struct coda_mount_data *data = _data;
184 
185 	if (!data)
186 		return invalf(fc, "coda: Bad mount data");
187 
188 	if (data->version != CODA_MOUNT_VERSION)
189 		return invalf(fc, "coda: Bad mount version");
190 
191 	file = fget(data->fd);
192 	if (file) {
193 		coda_set_idx(fc, file);
194 		fput(file);
195 	}
196 	return 0;
197 }
198 
199 static int coda_fill_super(struct super_block *sb, struct fs_context *fc)
200 {
201 	struct coda_fs_context *ctx = fc->fs_private;
202 	struct inode *root = NULL;
203 	struct venus_comm *vc;
204 	struct CodaFid fid;
205 	int error;
206 
207 	infof(fc, "coda: device index: %i\n", ctx->idx);
208 
209 	vc = &coda_comms[ctx->idx];
210 	mutex_lock(&vc->vc_mutex);
211 
212 	if (!vc->vc_inuse) {
213 		errorf(fc, "coda: No pseudo device");
214 		error = -EINVAL;
215 		goto unlock_out;
216 	}
217 
218 	if (vc->vc_sb) {
219 		errorf(fc, "coda: Device already mounted");
220 		error = -EBUSY;
221 		goto unlock_out;
222 	}
223 
224 	vc->vc_sb = sb;
225 	mutex_unlock(&vc->vc_mutex);
226 
227 	sb->s_fs_info = vc;
228 	sb->s_flags |= SB_NOATIME;
229 	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
230 	sb->s_blocksize_bits = 12;
231 	sb->s_magic = CODA_SUPER_MAGIC;
232 	sb->s_op = &coda_super_operations;
233 	sb->s_d_op = &coda_dentry_operations;
234 	sb->s_time_gran = 1;
235 	sb->s_time_min = S64_MIN;
236 	sb->s_time_max = S64_MAX;
237 
238 	error = super_setup_bdi(sb);
239 	if (error)
240 		goto error;
241 
242 	/* get root fid from Venus: this needs the root inode */
243 	error = venus_rootfid(sb, &fid);
244 	if ( error ) {
245 		pr_warn("%s: coda_get_rootfid failed with %d\n",
246 			__func__, error);
247 		goto error;
248 	}
249 	pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
250 
251 	/* make root inode */
252         root = coda_cnode_make(&fid, sb);
253         if (IS_ERR(root)) {
254 		error = PTR_ERR(root);
255 		pr_warn("Failure of coda_cnode_make for root: error %d\n",
256 			error);
257 		goto error;
258 	}
259 
260 	pr_info("%s: rootinode is %ld dev %s\n",
261 		__func__, root->i_ino, root->i_sb->s_id);
262 	sb->s_root = d_make_root(root);
263 	if (!sb->s_root) {
264 		error = -EINVAL;
265 		goto error;
266 	}
267 	return 0;
268 
269 error:
270 	mutex_lock(&vc->vc_mutex);
271 	vc->vc_sb = NULL;
272 	sb->s_fs_info = NULL;
273 unlock_out:
274 	mutex_unlock(&vc->vc_mutex);
275 	return error;
276 }
277 
278 static void coda_put_super(struct super_block *sb)
279 {
280 	struct venus_comm *vcp = coda_vcp(sb);
281 	mutex_lock(&vcp->vc_mutex);
282 	vcp->vc_sb = NULL;
283 	sb->s_fs_info = NULL;
284 	mutex_unlock(&vcp->vc_mutex);
285 	mutex_destroy(&vcp->vc_mutex);
286 
287 	pr_info("Bye bye.\n");
288 }
289 
290 static void coda_evict_inode(struct inode *inode)
291 {
292 	truncate_inode_pages_final(&inode->i_data);
293 	clear_inode(inode);
294 	coda_cache_clear_inode(inode);
295 }
296 
297 int coda_getattr(struct mnt_idmap *idmap, const struct path *path,
298 		 struct kstat *stat, u32 request_mask, unsigned int flags)
299 {
300 	int err = coda_revalidate_inode(d_inode(path->dentry));
301 	if (!err)
302 		generic_fillattr(&nop_mnt_idmap, request_mask,
303 				 d_inode(path->dentry), stat);
304 	return err;
305 }
306 
307 int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,
308 		 struct iattr *iattr)
309 {
310 	struct inode *inode = d_inode(de);
311 	struct coda_vattr vattr;
312 	int error;
313 
314 	memset(&vattr, 0, sizeof(vattr));
315 
316 	inode_set_ctime_current(inode);
317 	coda_iattr_to_vattr(iattr, &vattr);
318 	vattr.va_type = C_VNON; /* cannot set type */
319 
320 	/* Venus is responsible for truncating the container-file!!! */
321 	error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
322 
323 	if (!error) {
324 	        coda_vattr_to_iattr(inode, &vattr);
325 		coda_cache_clear_inode(inode);
326 	}
327 	return error;
328 }
329 
330 const struct inode_operations coda_file_inode_operations = {
331 	.permission	= coda_permission,
332 	.getattr	= coda_getattr,
333 	.setattr	= coda_setattr,
334 };
335 
336 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
337 {
338 	int error;
339 
340 	error = venus_statfs(dentry, buf);
341 
342 	if (error) {
343 		/* fake something like AFS does */
344 		buf->f_blocks = 9000000;
345 		buf->f_bfree  = 9000000;
346 		buf->f_bavail = 9000000;
347 		buf->f_files  = 9000000;
348 		buf->f_ffree  = 9000000;
349 	}
350 
351 	/* and fill in the rest */
352 	buf->f_type = CODA_SUPER_MAGIC;
353 	buf->f_bsize = 4096;
354 	buf->f_namelen = CODA_MAXNAMLEN;
355 
356 	return 0;
357 }
358 
359 static int coda_get_tree(struct fs_context *fc)
360 {
361 	if (task_active_pid_ns(current) != &init_pid_ns)
362 		return -EINVAL;
363 
364 	return get_tree_nodev(fc, coda_fill_super);
365 }
366 
367 static void coda_free_fc(struct fs_context *fc)
368 {
369 	kfree(fc->fs_private);
370 }
371 
372 static const struct fs_context_operations coda_context_ops = {
373 	.free		= coda_free_fc,
374 	.parse_param	= coda_parse_param,
375 	.parse_monolithic = coda_parse_monolithic,
376 	.get_tree	= coda_get_tree,
377 	.reconfigure	= coda_reconfigure,
378 };
379 
380 static int coda_init_fs_context(struct fs_context *fc)
381 {
382 	struct coda_fs_context *ctx;
383 
384 	ctx = kzalloc(sizeof(struct coda_fs_context), GFP_KERNEL);
385 	if (!ctx)
386 		return -ENOMEM;
387 
388 	fc->fs_private = ctx;
389 	fc->ops = &coda_context_ops;
390 	return 0;
391 }
392 
393 struct file_system_type coda_fs_type = {
394 	.owner		= THIS_MODULE,
395 	.name		= "coda",
396 	.init_fs_context = coda_init_fs_context,
397 	.parameters	= coda_param_specs,
398 	.kill_sb	= kill_anon_super,
399 	.fs_flags	= FS_BINARY_MOUNTDATA,
400 };
401 MODULE_ALIAS_FS("coda");
402 
403