xref: /linux/fs/coda/inode.c (revision 8bc7c5e525584903ea83332e18a2118ed3b1985e) 
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_parse_fd(struct fs_context *fc, int fd)
123 {
124 	struct coda_fs_context *ctx = fc->fs_private;
125 	struct fd f;
126 	struct inode *inode;
127 	int idx;
128 
129 	f = fdget(fd);
130 	if (!f.file)
131 		return -EBADF;
132 	inode = file_inode(f.file);
133 	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
134 		fdput(f);
135 		return invalf(fc, "code: Not coda psdev");
136 	}
137 
138 	idx = iminor(inode);
139 	fdput(f);
140 
141 	if (idx < 0 || idx >= MAX_CODADEVS)
142 		return invalf(fc, "coda: Bad minor number");
143 	ctx->idx = idx;
144 	return 0;
145 }
146 
147 static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param)
148 {
149 	struct fs_parse_result result;
150 	int opt;
151 
152 	opt = fs_parse(fc, coda_param_specs, param, &result);
153 	if (opt < 0)
154 		return opt;
155 
156 	switch (opt) {
157 	case Opt_fd:
158 		return coda_parse_fd(fc, result.uint_32);
159 	}
160 
161 	return 0;
162 }
163 
164 /*
165  * Parse coda's binary mount data form.  We ignore any errors and go with index
166  * 0 if we get one for backward compatibility.
167  */
168 static int coda_parse_monolithic(struct fs_context *fc, void *_data)
169 {
170 	struct coda_mount_data *data = _data;
171 
172 	if (!data)
173 		return invalf(fc, "coda: Bad mount data");
174 
175 	if (data->version != CODA_MOUNT_VERSION)
176 		return invalf(fc, "coda: Bad mount version");
177 
178 	coda_parse_fd(fc, data->fd);
179 	return 0;
180 }
181 
182 static int coda_fill_super(struct super_block *sb, struct fs_context *fc)
183 {
184 	struct coda_fs_context *ctx = fc->fs_private;
185 	struct inode *root = NULL;
186 	struct venus_comm *vc;
187 	struct CodaFid fid;
188 	int error;
189 
190 	infof(fc, "coda: device index: %i\n", ctx->idx);
191 
192 	vc = &coda_comms[ctx->idx];
193 	mutex_lock(&vc->vc_mutex);
194 
195 	if (!vc->vc_inuse) {
196 		errorf(fc, "coda: No pseudo device");
197 		error = -EINVAL;
198 		goto unlock_out;
199 	}
200 
201 	if (vc->vc_sb) {
202 		errorf(fc, "coda: Device already mounted");
203 		error = -EBUSY;
204 		goto unlock_out;
205 	}
206 
207 	vc->vc_sb = sb;
208 	mutex_unlock(&vc->vc_mutex);
209 
210 	sb->s_fs_info = vc;
211 	sb->s_flags |= SB_NOATIME;
212 	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
213 	sb->s_blocksize_bits = 12;
214 	sb->s_magic = CODA_SUPER_MAGIC;
215 	sb->s_op = &coda_super_operations;
216 	sb->s_d_op = &coda_dentry_operations;
217 	sb->s_time_gran = 1;
218 	sb->s_time_min = S64_MIN;
219 	sb->s_time_max = S64_MAX;
220 
221 	error = super_setup_bdi(sb);
222 	if (error)
223 		goto error;
224 
225 	/* get root fid from Venus: this needs the root inode */
226 	error = venus_rootfid(sb, &fid);
227 	if ( error ) {
228 		pr_warn("%s: coda_get_rootfid failed with %d\n",
229 			__func__, error);
230 		goto error;
231 	}
232 	pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
233 
234 	/* make root inode */
235         root = coda_cnode_make(&fid, sb);
236         if (IS_ERR(root)) {
237 		error = PTR_ERR(root);
238 		pr_warn("Failure of coda_cnode_make for root: error %d\n",
239 			error);
240 		goto error;
241 	}
242 
243 	pr_info("%s: rootinode is %ld dev %s\n",
244 		__func__, root->i_ino, root->i_sb->s_id);
245 	sb->s_root = d_make_root(root);
246 	if (!sb->s_root) {
247 		error = -EINVAL;
248 		goto error;
249 	}
250 	return 0;
251 
252 error:
253 	mutex_lock(&vc->vc_mutex);
254 	vc->vc_sb = NULL;
255 	sb->s_fs_info = NULL;
256 unlock_out:
257 	mutex_unlock(&vc->vc_mutex);
258 	return error;
259 }
260 
261 static void coda_put_super(struct super_block *sb)
262 {
263 	struct venus_comm *vcp = coda_vcp(sb);
264 	mutex_lock(&vcp->vc_mutex);
265 	vcp->vc_sb = NULL;
266 	sb->s_fs_info = NULL;
267 	mutex_unlock(&vcp->vc_mutex);
268 	mutex_destroy(&vcp->vc_mutex);
269 
270 	pr_info("Bye bye.\n");
271 }
272 
273 static void coda_evict_inode(struct inode *inode)
274 {
275 	truncate_inode_pages_final(&inode->i_data);
276 	clear_inode(inode);
277 	coda_cache_clear_inode(inode);
278 }
279 
280 int coda_getattr(struct mnt_idmap *idmap, const struct path *path,
281 		 struct kstat *stat, u32 request_mask, unsigned int flags)
282 {
283 	int err = coda_revalidate_inode(d_inode(path->dentry));
284 	if (!err)
285 		generic_fillattr(&nop_mnt_idmap, request_mask,
286 				 d_inode(path->dentry), stat);
287 	return err;
288 }
289 
290 int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,
291 		 struct iattr *iattr)
292 {
293 	struct inode *inode = d_inode(de);
294 	struct coda_vattr vattr;
295 	int error;
296 
297 	memset(&vattr, 0, sizeof(vattr));
298 
299 	inode_set_ctime_current(inode);
300 	coda_iattr_to_vattr(iattr, &vattr);
301 	vattr.va_type = C_VNON; /* cannot set type */
302 
303 	/* Venus is responsible for truncating the container-file!!! */
304 	error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
305 
306 	if (!error) {
307 	        coda_vattr_to_iattr(inode, &vattr);
308 		coda_cache_clear_inode(inode);
309 	}
310 	return error;
311 }
312 
313 const struct inode_operations coda_file_inode_operations = {
314 	.permission	= coda_permission,
315 	.getattr	= coda_getattr,
316 	.setattr	= coda_setattr,
317 };
318 
319 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
320 {
321 	int error;
322 
323 	error = venus_statfs(dentry, buf);
324 
325 	if (error) {
326 		/* fake something like AFS does */
327 		buf->f_blocks = 9000000;
328 		buf->f_bfree  = 9000000;
329 		buf->f_bavail = 9000000;
330 		buf->f_files  = 9000000;
331 		buf->f_ffree  = 9000000;
332 	}
333 
334 	/* and fill in the rest */
335 	buf->f_type = CODA_SUPER_MAGIC;
336 	buf->f_bsize = 4096;
337 	buf->f_namelen = CODA_MAXNAMLEN;
338 
339 	return 0;
340 }
341 
342 static int coda_get_tree(struct fs_context *fc)
343 {
344 	if (task_active_pid_ns(current) != &init_pid_ns)
345 		return -EINVAL;
346 
347 	return get_tree_nodev(fc, coda_fill_super);
348 }
349 
350 static void coda_free_fc(struct fs_context *fc)
351 {
352 	kfree(fc->fs_private);
353 }
354 
355 static const struct fs_context_operations coda_context_ops = {
356 	.free		= coda_free_fc,
357 	.parse_param	= coda_parse_param,
358 	.parse_monolithic = coda_parse_monolithic,
359 	.get_tree	= coda_get_tree,
360 	.reconfigure	= coda_reconfigure,
361 };
362 
363 static int coda_init_fs_context(struct fs_context *fc)
364 {
365 	struct coda_fs_context *ctx;
366 
367 	ctx = kzalloc(sizeof(struct coda_fs_context), GFP_KERNEL);
368 	if (!ctx)
369 		return -ENOMEM;
370 
371 	fc->fs_private = ctx;
372 	fc->ops = &coda_context_ops;
373 	return 0;
374 }
375 
376 struct file_system_type coda_fs_type = {
377 	.owner		= THIS_MODULE,
378 	.name		= "coda",
379 	.init_fs_context = coda_init_fs_context,
380 	.parameters	= coda_param_specs,
381 	.kill_sb	= kill_anon_super,
382 	.fs_flags	= FS_BINARY_MOUNTDATA,
383 };
384 MODULE_ALIAS_FS("coda");
385 
386