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
coda_alloc_inode(struct super_block * sb)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
coda_free_inode(struct inode * inode)59 static void coda_free_inode(struct inode *inode)
60 {
61 kmem_cache_free(coda_inode_cachep, ITOC(inode));
62 }
63
init_once(void * foo)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
coda_init_inodecache(void)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
coda_destroy_inodecache(void)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
coda_reconfigure(struct fs_context * fc)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
coda_set_idx(struct fs_context * fc,struct file * file)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
coda_parse_fd(struct fs_context * fc,struct fs_parameter * param,struct fs_parse_result * result)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
coda_parse_param(struct fs_context * fc,struct fs_parameter * param)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 */
coda_parse_monolithic(struct fs_context * fc,void * _data)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
coda_fill_super(struct super_block * sb,struct fs_context * fc)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
coda_put_super(struct super_block * sb)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
coda_evict_inode(struct inode * inode)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
coda_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)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
coda_setattr(struct mnt_idmap * idmap,struct dentry * de,struct iattr * iattr)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
coda_statfs(struct dentry * dentry,struct kstatfs * buf)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
coda_get_tree(struct fs_context * fc)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
coda_free_fc(struct fs_context * fc)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
coda_init_fs_context(struct fs_context * fc)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