xref: /openbmc/linux/fs/coda/inode.c (revision ca79522c) 
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 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 	*flags |= MS_NOATIME;
100 	return 0;
101 }
102 
103 /* exported operations */
104 static const struct super_operations coda_super_operations =
105 {
106 	.alloc_inode	= coda_alloc_inode,
107 	.destroy_inode	= coda_destroy_inode,
108 	.evict_inode	= coda_evict_inode,
109 	.put_super	= coda_put_super,
110 	.statfs		= coda_statfs,
111 	.remount_fs	= coda_remount,
112 };
113 
114 static int get_device_index(struct coda_mount_data *data)
115 {
116 	struct fd f;
117 	struct inode *inode;
118 	int idx;
119 
120 	if (data == NULL) {
121 		printk("coda_read_super: Bad mount data\n");
122 		return -1;
123 	}
124 
125 	if (data->version != CODA_MOUNT_VERSION) {
126 		printk("coda_read_super: Bad mount version\n");
127 		return -1;
128 	}
129 
130 	f = fdget(data->fd);
131 	if (!f.file)
132 		goto Ebadf;
133 	inode = file_inode(f.file);
134 	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
135 		fdput(f);
136 		goto Ebadf;
137 	}
138 
139 	idx = iminor(inode);
140 	fdput(f);
141 
142 	if (idx < 0 || idx >= MAX_CODADEVS) {
143 		printk("coda_read_super: Bad minor number\n");
144 		return -1;
145 	}
146 
147 	return idx;
148 Ebadf:
149 	printk("coda_read_super: Bad file\n");
150 	return -1;
151 }
152 
153 static int coda_fill_super(struct super_block *sb, void *data, int silent)
154 {
155 	struct inode *root = NULL;
156 	struct venus_comm *vc;
157 	struct CodaFid fid;
158 	int error;
159 	int idx;
160 
161 	if (task_active_pid_ns(current) != &init_pid_ns)
162 		return -EINVAL;
163 
164 	idx = get_device_index((struct coda_mount_data *) data);
165 
166 	/* Ignore errors in data, for backward compatibility */
167 	if(idx == -1)
168 		idx = 0;
169 
170 	printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
171 
172 	vc = &coda_comms[idx];
173 	mutex_lock(&vc->vc_mutex);
174 
175 	if (!vc->vc_inuse) {
176 		printk("coda_read_super: No pseudo device\n");
177 		error = -EINVAL;
178 		goto unlock_out;
179 	}
180 
181 	if (vc->vc_sb) {
182 		printk("coda_read_super: Device already mounted\n");
183 		error = -EBUSY;
184 		goto unlock_out;
185 	}
186 
187 	error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
188 	if (error)
189 		goto unlock_out;
190 
191 	vc->vc_sb = sb;
192 	mutex_unlock(&vc->vc_mutex);
193 
194 	sb->s_fs_info = vc;
195 	sb->s_flags |= MS_NOATIME;
196 	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
197 	sb->s_blocksize_bits = 12;
198 	sb->s_magic = CODA_SUPER_MAGIC;
199 	sb->s_op = &coda_super_operations;
200 	sb->s_d_op = &coda_dentry_operations;
201 	sb->s_bdi = &vc->bdi;
202 
203 	/* get root fid from Venus: this needs the root inode */
204 	error = venus_rootfid(sb, &fid);
205 	if ( error ) {
206 	        printk("coda_read_super: coda_get_rootfid failed with %d\n",
207 		       error);
208 		goto error;
209 	}
210 	printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
211 
212 	/* make root inode */
213         root = coda_cnode_make(&fid, sb);
214         if (IS_ERR(root)) {
215 		error = PTR_ERR(root);
216 		printk("Failure of coda_cnode_make for root: error %d\n", error);
217 		goto error;
218 	}
219 
220 	printk("coda_read_super: rootinode is %ld dev %s\n",
221 	       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 	printk("Coda: Bye bye.\n");
249 }
250 
251 static void coda_evict_inode(struct inode *inode)
252 {
253 	truncate_inode_pages(&inode->i_data, 0);
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(dentry);
261 	if (!err)
262 		generic_fillattr(dentry->d_inode, stat);
263 	return err;
264 }
265 
266 int coda_setattr(struct dentry *de, struct iattr *iattr)
267 {
268 	struct inode *inode = de->d_inode;
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