1/*
2 * Super block/filesystem wide operations
3 *
4 * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
5 * Michael Callahan <callahan@maths.ox.ac.uk>
6 *
7 * Rewritten for Linux 2.1.  Peter Braam <braam@cs.cmu.edu>
8 * Copyright (C) Carnegie Mellon University
9 */
10
11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/mm.h>
14#include <linux/string.h>
15#include <linux/stat.h>
16#include <linux/errno.h>
17#include <linux/unistd.h>
18#include <linux/mutex.h>
19#include <linux/spinlock.h>
20#include <linux/file.h>
21#include <linux/vfs.h>
22#include <linux/slab.h>
23#include <linux/pid_namespace.h>
24#include <linux/uaccess.h>
25#include <linux/fs.h>
26#include <linux/vmalloc.h>
27
28#include <linux/coda.h>
29#include <linux/coda_psdev.h>
30#include "coda_linux.h"
31#include "coda_cache.h"
32
33#include "coda_int.h"
34
35/* VFS super_block ops */
36static void coda_evict_inode(struct inode *);
37static void coda_put_super(struct super_block *);
38static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
39
40static struct kmem_cache * coda_inode_cachep;
41
42static struct inode *coda_alloc_inode(struct super_block *sb)
43{
44	struct coda_inode_info *ei;
45	ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
46	if (!ei)
47		return NULL;
48	memset(&ei->c_fid, 0, sizeof(struct CodaFid));
49	ei->c_flags = 0;
50	ei->c_uid = GLOBAL_ROOT_UID;
51	ei->c_cached_perm = 0;
52	spin_lock_init(&ei->c_lock);
53	return &ei->vfs_inode;
54}
55
56static void coda_i_callback(struct rcu_head *head)
57{
58	struct inode *inode = container_of(head, struct inode, i_rcu);
59	kmem_cache_free(coda_inode_cachep, ITOC(inode));
60}
61
62static void coda_destroy_inode(struct inode *inode)
63{
64	call_rcu(&inode->i_rcu, coda_i_callback);
65}
66
67static void init_once(void *foo)
68{
69	struct coda_inode_info *ei = (struct coda_inode_info *) foo;
70
71	inode_init_once(&ei->vfs_inode);
72}
73
74int __init coda_init_inodecache(void)
75{
76	coda_inode_cachep = kmem_cache_create("coda_inode_cache",
77				sizeof(struct coda_inode_info),
78				0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
79				init_once);
80	if (coda_inode_cachep == NULL)
81		return -ENOMEM;
82	return 0;
83}
84
85void coda_destroy_inodecache(void)
86{
87	/*
88	 * Make sure all delayed rcu free inodes are flushed before we
89	 * destroy cache.
90	 */
91	rcu_barrier();
92	kmem_cache_destroy(coda_inode_cachep);
93}
94
95static int coda_remount(struct super_block *sb, int *flags, char *data)
96{
97	sync_filesystem(sb);
98	*flags |= MS_NOATIME;
99	return 0;
100}
101
102/* exported operations */
103static const struct super_operations coda_super_operations =
104{
105	.alloc_inode	= coda_alloc_inode,
106	.destroy_inode	= coda_destroy_inode,
107	.evict_inode	= coda_evict_inode,
108	.put_super	= coda_put_super,
109	.statfs		= coda_statfs,
110	.remount_fs	= coda_remount,
111};
112
113static int get_device_index(struct coda_mount_data *data)
114{
115	struct fd f;
116	struct inode *inode;
117	int idx;
118
119	if (data == NULL) {
120		pr_warn("%s: Bad mount data\n", __func__);
121		return -1;
122	}
123
124	if (data->version != CODA_MOUNT_VERSION) {
125		pr_warn("%s: Bad mount version\n", __func__);
126		return -1;
127	}
128
129	f = fdget(data->fd);
130	if (!f.file)
131		goto Ebadf;
132	inode = file_inode(f.file);
133	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
134		fdput(f);
135		goto Ebadf;
136	}
137
138	idx = iminor(inode);
139	fdput(f);
140
141	if (idx < 0 || idx >= MAX_CODADEVS) {
142		pr_warn("%s: Bad minor number\n", __func__);
143		return -1;
144	}
145
146	return idx;
147Ebadf:
148	pr_warn("%s: Bad file\n", __func__);
149	return -1;
150}
151
152static int coda_fill_super(struct super_block *sb, void *data, int silent)
153{
154	struct inode *root = NULL;
155	struct venus_comm *vc;
156	struct CodaFid fid;
157	int error;
158	int idx;
159
160	if (task_active_pid_ns(current) != &init_pid_ns)
161		return -EINVAL;
162
163	idx = get_device_index((struct coda_mount_data *) data);
164
165	/* Ignore errors in data, for backward compatibility */
166	if(idx == -1)
167		idx = 0;
168
169	pr_info("%s: device index: %i\n", __func__,  idx);
170
171	vc = &coda_comms[idx];
172	mutex_lock(&vc->vc_mutex);
173
174	if (!vc->vc_inuse) {
175		pr_warn("%s: No pseudo device\n", __func__);
176		error = -EINVAL;
177		goto unlock_out;
178	}
179
180	if (vc->vc_sb) {
181		pr_warn("%s: Device already mounted\n", __func__);
182		error = -EBUSY;
183		goto unlock_out;
184	}
185
186	error = bdi_setup_and_register(&vc->bdi, "coda");
187	if (error)
188		goto unlock_out;
189
190	vc->vc_sb = sb;
191	mutex_unlock(&vc->vc_mutex);
192
193	sb->s_fs_info = vc;
194	sb->s_flags |= MS_NOATIME;
195	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
196	sb->s_blocksize_bits = 12;
197	sb->s_magic = CODA_SUPER_MAGIC;
198	sb->s_op = &coda_super_operations;
199	sb->s_d_op = &coda_dentry_operations;
200	sb->s_bdi = &vc->bdi;
201
202	/* get root fid from Venus: this needs the root inode */
203	error = venus_rootfid(sb, &fid);
204	if ( error ) {
205		pr_warn("%s: coda_get_rootfid failed with %d\n",
206			__func__, error);
207		goto error;
208	}
209	pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
210
211	/* make root inode */
212        root = coda_cnode_make(&fid, sb);
213        if (IS_ERR(root)) {
214		error = PTR_ERR(root);
215		pr_warn("Failure of coda_cnode_make for root: error %d\n",
216			error);
217		goto error;
218	}
219
220	pr_info("%s: rootinode is %ld dev %s\n",
221		__func__, root->i_ino, root->i_sb->s_id);
222	sb->s_root = d_make_root(root);
223	if (!sb->s_root) {
224		error = -EINVAL;
225		goto error;
226	}
227	return 0;
228
229error:
230	mutex_lock(&vc->vc_mutex);
231	bdi_destroy(&vc->bdi);
232	vc->vc_sb = NULL;
233	sb->s_fs_info = NULL;
234unlock_out:
235	mutex_unlock(&vc->vc_mutex);
236	return error;
237}
238
239static void coda_put_super(struct super_block *sb)
240{
241	struct venus_comm *vcp = coda_vcp(sb);
242	mutex_lock(&vcp->vc_mutex);
243	bdi_destroy(&vcp->bdi);
244	vcp->vc_sb = NULL;
245	sb->s_fs_info = NULL;
246	mutex_unlock(&vcp->vc_mutex);
247
248	pr_info("Bye bye.\n");
249}
250
251static void coda_evict_inode(struct inode *inode)
252{
253	truncate_inode_pages_final(&inode->i_data);
254	clear_inode(inode);
255	coda_cache_clear_inode(inode);
256}
257
258int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
259{
260	int err = coda_revalidate_inode(d_inode(dentry));
261	if (!err)
262		generic_fillattr(d_inode(dentry), stat);
263	return err;
264}
265
266int coda_setattr(struct dentry *de, struct iattr *iattr)
267{
268	struct inode *inode = d_inode(de);
269	struct coda_vattr vattr;
270	int error;
271
272	memset(&vattr, 0, sizeof(vattr));
273
274	inode->i_ctime = CURRENT_TIME_SEC;
275	coda_iattr_to_vattr(iattr, &vattr);
276	vattr.va_type = C_VNON; /* cannot set type */
277
278	/* Venus is responsible for truncating the container-file!!! */
279	error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
280
281	if (!error) {
282	        coda_vattr_to_iattr(inode, &vattr);
283		coda_cache_clear_inode(inode);
284	}
285	return error;
286}
287
288const struct inode_operations coda_file_inode_operations = {
289	.permission	= coda_permission,
290	.getattr	= coda_getattr,
291	.setattr	= coda_setattr,
292};
293
294static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
295{
296	int error;
297
298	error = venus_statfs(dentry, buf);
299
300	if (error) {
301		/* fake something like AFS does */
302		buf->f_blocks = 9000000;
303		buf->f_bfree  = 9000000;
304		buf->f_bavail = 9000000;
305		buf->f_files  = 9000000;
306		buf->f_ffree  = 9000000;
307	}
308
309	/* and fill in the rest */
310	buf->f_type = CODA_SUPER_MAGIC;
311	buf->f_bsize = 4096;
312	buf->f_namelen = CODA_MAXNAMLEN;
313
314	return 0;
315}
316
317/* init_coda: used by filesystems.c to register coda */
318
319static struct dentry *coda_mount(struct file_system_type *fs_type,
320	int flags, const char *dev_name, void *data)
321{
322	return mount_nodev(fs_type, flags, data, coda_fill_super);
323}
324
325struct file_system_type coda_fs_type = {
326	.owner		= THIS_MODULE,
327	.name		= "coda",
328	.mount		= coda_mount,
329	.kill_sb	= kill_anon_super,
330	.fs_flags	= FS_BINARY_MOUNTDATA,
331};
332MODULE_ALIAS_FS("coda");
333
334