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, cache: 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(s: coda_inode_cachep, objp: 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(name: "coda_inode_cache" , |
74 | size: sizeof(struct coda_inode_info), align: 0, |
75 | SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT, |
76 | ctor: 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(s: 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: f.file); |
133 | if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) { |
134 | fdput(fd: f); |
135 | return invalf(fc, "code: Not coda psdev" ); |
136 | } |
137 | |
138 | idx = iminor(inode); |
139 | fdput(fd: 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, desc: coda_param_specs, param, result: &result); |
153 | if (opt < 0) |
154 | return opt; |
155 | |
156 | switch (opt) { |
157 | case Opt_fd: |
158 | return coda_parse_fd(fc, fd: 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, fd: 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(lock: &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, fidp: &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(ptr: root)) { |
237 | error = PTR_ERR(ptr: 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(lock: &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(lock: &vcp->vc_mutex); |
268 | mutex_destroy(lock: &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(dentry: path->dentry)); |
284 | if (!err) |
285 | generic_fillattr(&nop_mnt_idmap, request_mask, |
286 | d_inode(dentry: 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(dentry: 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, sfs: 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, fill_super: coda_fill_super); |
348 | } |
349 | |
350 | static void coda_free_fc(struct fs_context *fc) |
351 | { |
352 | kfree(objp: 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(size: 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 | |