xref: /openbmc/linux/fs/coda/inode.c (revision 976fa9a3) 
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 */
36 static void coda_evict_inode(struct inode *);
37 static void coda_put_super(struct super_block *);
38 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
39 
40 static struct kmem_cache * coda_inode_cachep;
41 
42 static 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 
56 static 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 
62 static void coda_destroy_inode(struct inode *inode)
63 {
64 	call_rcu(&inode->i_rcu, coda_i_callback);
65 }
66 
67 static 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 
74 int __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 
85 void 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 
95 static 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 */
103 static 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 
113 static 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;
147 Ebadf:
148 	pr_warn("%s: Bad file\n", __func__);
149 	return -1;
150 }
151 
152 static 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 
229 error:
230 	mutex_lock(&vc->vc_mutex);
231 	bdi_destroy(&vc->bdi);
232 	vc->vc_sb = NULL;
233 	sb->s_fs_info = NULL;
234 unlock_out:
235 	mutex_unlock(&vc->vc_mutex);
236 	return error;
237 }
238 
239 static 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 
251 static 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 
258 int 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 
266 int 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 
288 const struct inode_operations coda_file_inode_operations = {
289 	.permission	= coda_permission,
290 	.getattr	= coda_getattr,
291 	.setattr	= coda_setattr,
292 };
293 
294 static 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 
319 static 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 
325 struct 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 };
332 MODULE_ALIAS_FS("coda");
333 
334