xref: /openbmc/linux/fs/coda/inode.c (revision db181ce0) 
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 
25 #include <asm/uaccess.h>
26 
27 #include <linux/fs.h>
28 #include <linux/vmalloc.h>
29 
30 #include <linux/coda.h>
31 #include <linux/coda_psdev.h>
32 #include "coda_linux.h"
33 #include "coda_cache.h"
34 
35 #include "coda_int.h"
36 
37 /* VFS super_block ops */
38 static void coda_evict_inode(struct inode *);
39 static void coda_put_super(struct super_block *);
40 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
41 
42 static struct kmem_cache * coda_inode_cachep;
43 
44 static struct inode *coda_alloc_inode(struct super_block *sb)
45 {
46 	struct coda_inode_info *ei;
47 	ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
48 	if (!ei)
49 		return NULL;
50 	memset(&ei->c_fid, 0, sizeof(struct CodaFid));
51 	ei->c_flags = 0;
52 	ei->c_uid = GLOBAL_ROOT_UID;
53 	ei->c_cached_perm = 0;
54 	spin_lock_init(&ei->c_lock);
55 	return &ei->vfs_inode;
56 }
57 
58 static void coda_i_callback(struct rcu_head *head)
59 {
60 	struct inode *inode = container_of(head, struct inode, i_rcu);
61 	kmem_cache_free(coda_inode_cachep, ITOC(inode));
62 }
63 
64 static void coda_destroy_inode(struct inode *inode)
65 {
66 	call_rcu(&inode->i_rcu, coda_i_callback);
67 }
68 
69 static void init_once(void *foo)
70 {
71 	struct coda_inode_info *ei = (struct coda_inode_info *) foo;
72 
73 	inode_init_once(&ei->vfs_inode);
74 }
75 
76 int __init coda_init_inodecache(void)
77 {
78 	coda_inode_cachep = kmem_cache_create("coda_inode_cache",
79 				sizeof(struct coda_inode_info),
80 				0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
81 				init_once);
82 	if (coda_inode_cachep == NULL)
83 		return -ENOMEM;
84 	return 0;
85 }
86 
87 void coda_destroy_inodecache(void)
88 {
89 	/*
90 	 * Make sure all delayed rcu free inodes are flushed before we
91 	 * destroy cache.
92 	 */
93 	rcu_barrier();
94 	kmem_cache_destroy(coda_inode_cachep);
95 }
96 
97 static int coda_remount(struct super_block *sb, int *flags, char *data)
98 {
99 	sync_filesystem(sb);
100 	*flags |= MS_NOATIME;
101 	return 0;
102 }
103 
104 /* exported operations */
105 static const struct super_operations coda_super_operations =
106 {
107 	.alloc_inode	= coda_alloc_inode,
108 	.destroy_inode	= coda_destroy_inode,
109 	.evict_inode	= coda_evict_inode,
110 	.put_super	= coda_put_super,
111 	.statfs		= coda_statfs,
112 	.remount_fs	= coda_remount,
113 };
114 
115 static int get_device_index(struct coda_mount_data *data)
116 {
117 	struct fd f;
118 	struct inode *inode;
119 	int idx;
120 
121 	if (data == NULL) {
122 		pr_warn("%s: Bad mount data\n", __func__);
123 		return -1;
124 	}
125 
126 	if (data->version != CODA_MOUNT_VERSION) {
127 		pr_warn("%s: Bad mount version\n", __func__);
128 		return -1;
129 	}
130 
131 	f = fdget(data->fd);
132 	if (!f.file)
133 		goto Ebadf;
134 	inode = file_inode(f.file);
135 	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
136 		fdput(f);
137 		goto Ebadf;
138 	}
139 
140 	idx = iminor(inode);
141 	fdput(f);
142 
143 	if (idx < 0 || idx >= MAX_CODADEVS) {
144 		pr_warn("%s: Bad minor number\n", __func__);
145 		return -1;
146 	}
147 
148 	return idx;
149 Ebadf:
150 	pr_warn("%s: Bad file\n", __func__);
151 	return -1;
152 }
153 
154 static int coda_fill_super(struct super_block *sb, void *data, int silent)
155 {
156 	struct inode *root = NULL;
157 	struct venus_comm *vc;
158 	struct CodaFid fid;
159 	int error;
160 	int idx;
161 
162 	if (task_active_pid_ns(current) != &init_pid_ns)
163 		return -EINVAL;
164 
165 	idx = get_device_index((struct coda_mount_data *) data);
166 
167 	/* Ignore errors in data, for backward compatibility */
168 	if(idx == -1)
169 		idx = 0;
170 
171 	pr_info("%s: device index: %i\n", __func__,  idx);
172 
173 	vc = &coda_comms[idx];
174 	mutex_lock(&vc->vc_mutex);
175 
176 	if (!vc->vc_inuse) {
177 		pr_warn("%s: No pseudo device\n", __func__);
178 		error = -EINVAL;
179 		goto unlock_out;
180 	}
181 
182 	if (vc->vc_sb) {
183 		pr_warn("%s: Device already mounted\n", __func__);
184 		error = -EBUSY;
185 		goto unlock_out;
186 	}
187 
188 	error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
189 	if (error)
190 		goto unlock_out;
191 
192 	vc->vc_sb = sb;
193 	mutex_unlock(&vc->vc_mutex);
194 
195 	sb->s_fs_info = vc;
196 	sb->s_flags |= MS_NOATIME;
197 	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
198 	sb->s_blocksize_bits = 12;
199 	sb->s_magic = CODA_SUPER_MAGIC;
200 	sb->s_op = &coda_super_operations;
201 	sb->s_d_op = &coda_dentry_operations;
202 	sb->s_bdi = &vc->bdi;
203 
204 	/* get root fid from Venus: this needs the root inode */
205 	error = venus_rootfid(sb, &fid);
206 	if ( error ) {
207 		pr_warn("%s: coda_get_rootfid failed with %d\n",
208 			__func__, error);
209 		goto error;
210 	}
211 	pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
212 
213 	/* make root inode */
214         root = coda_cnode_make(&fid, sb);
215         if (IS_ERR(root)) {
216 		error = PTR_ERR(root);
217 		pr_warn("Failure of coda_cnode_make for root: error %d\n",
218 			error);
219 		goto error;
220 	}
221 
222 	pr_info("%s: rootinode is %ld dev %s\n",
223 		__func__, root->i_ino, root->i_sb->s_id);
224 	sb->s_root = d_make_root(root);
225 	if (!sb->s_root) {
226 		error = -EINVAL;
227 		goto error;
228 	}
229 	return 0;
230 
231 error:
232 	mutex_lock(&vc->vc_mutex);
233 	bdi_destroy(&vc->bdi);
234 	vc->vc_sb = NULL;
235 	sb->s_fs_info = NULL;
236 unlock_out:
237 	mutex_unlock(&vc->vc_mutex);
238 	return error;
239 }
240 
241 static void coda_put_super(struct super_block *sb)
242 {
243 	struct venus_comm *vcp = coda_vcp(sb);
244 	mutex_lock(&vcp->vc_mutex);
245 	bdi_destroy(&vcp->bdi);
246 	vcp->vc_sb = NULL;
247 	sb->s_fs_info = NULL;
248 	mutex_unlock(&vcp->vc_mutex);
249 
250 	pr_info("Bye bye.\n");
251 }
252 
253 static void coda_evict_inode(struct inode *inode)
254 {
255 	truncate_inode_pages_final(&inode->i_data);
256 	clear_inode(inode);
257 	coda_cache_clear_inode(inode);
258 }
259 
260 int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
261 {
262 	int err = coda_revalidate_inode(dentry->d_inode);
263 	if (!err)
264 		generic_fillattr(dentry->d_inode, stat);
265 	return err;
266 }
267 
268 int coda_setattr(struct dentry *de, struct iattr *iattr)
269 {
270 	struct inode *inode = de->d_inode;
271 	struct coda_vattr vattr;
272 	int error;
273 
274 	memset(&vattr, 0, sizeof(vattr));
275 
276 	inode->i_ctime = CURRENT_TIME_SEC;
277 	coda_iattr_to_vattr(iattr, &vattr);
278 	vattr.va_type = C_VNON; /* cannot set type */
279 
280 	/* Venus is responsible for truncating the container-file!!! */
281 	error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
282 
283 	if (!error) {
284 	        coda_vattr_to_iattr(inode, &vattr);
285 		coda_cache_clear_inode(inode);
286 	}
287 	return error;
288 }
289 
290 const struct inode_operations coda_file_inode_operations = {
291 	.permission	= coda_permission,
292 	.getattr	= coda_getattr,
293 	.setattr	= coda_setattr,
294 };
295 
296 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
297 {
298 	int error;
299 
300 	error = venus_statfs(dentry, buf);
301 
302 	if (error) {
303 		/* fake something like AFS does */
304 		buf->f_blocks = 9000000;
305 		buf->f_bfree  = 9000000;
306 		buf->f_bavail = 9000000;
307 		buf->f_files  = 9000000;
308 		buf->f_ffree  = 9000000;
309 	}
310 
311 	/* and fill in the rest */
312 	buf->f_type = CODA_SUPER_MAGIC;
313 	buf->f_bsize = 4096;
314 	buf->f_namelen = CODA_MAXNAMLEN;
315 
316 	return 0;
317 }
318 
319 /* init_coda: used by filesystems.c to register coda */
320 
321 static struct dentry *coda_mount(struct file_system_type *fs_type,
322 	int flags, const char *dev_name, void *data)
323 {
324 	return mount_nodev(fs_type, flags, data, coda_fill_super);
325 }
326 
327 struct file_system_type coda_fs_type = {
328 	.owner		= THIS_MODULE,
329 	.name		= "coda",
330 	.mount		= coda_mount,
331 	.kill_sb	= kill_anon_super,
332 	.fs_flags	= FS_BINARY_MOUNTDATA,
333 };
334 MODULE_ALIAS_FS("coda");
335 
336