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 */
39static void coda_evict_inode(struct inode *);
40static void coda_put_super(struct super_block *);
41static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
42
43static struct kmem_cache * coda_inode_cachep;
44
45static 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
59static void coda_free_inode(struct inode *inode)
60{
61	kmem_cache_free(coda_inode_cachep, ITOC(inode));
62}
63
64static 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
71int __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
82void 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
92static 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 */
100static 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
109struct coda_fs_context {
110	int	idx;
111};
112
113enum {
114	Opt_fd,
115};
116
117static const struct fs_parameter_spec coda_param_specs[] = {
118	fsparam_fd	("fd",	Opt_fd),
119	{}
120};
121
122static 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
147static 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 */
168static 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
182static 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
252error:
253	mutex_lock(&vc->vc_mutex);
254	vc->vc_sb = NULL;
255	sb->s_fs_info = NULL;
256unlock_out:
257	mutex_unlock(&vc->vc_mutex);
258	return error;
259}
260
261static 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
273static 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
280int 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
290int 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
313const struct inode_operations coda_file_inode_operations = {
314	.permission	= coda_permission,
315	.getattr	= coda_getattr,
316	.setattr	= coda_setattr,
317};
318
319static 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
342static 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
350static void coda_free_fc(struct fs_context *fc)
351{
352	kfree(fc->fs_private);
353}
354
355static 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
363static 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
376struct 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};
384MODULE_ALIAS_FS("coda");
385
386