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
coda_alloc_inode(struct super_block * sb)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
coda_i_callback(struct rcu_head * head)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
coda_destroy_inode(struct inode * inode)62 static void coda_destroy_inode(struct inode *inode)
63 {
64 call_rcu(&inode->i_rcu, coda_i_callback);
65 }
66
init_once(void * foo)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
coda_init_inodecache(void)74 int __init coda_init_inodecache(void)
75 {
76 coda_inode_cachep = kmem_cache_create("coda_inode_cache",
77 sizeof(struct coda_inode_info), 0,
78 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
79 SLAB_ACCOUNT, init_once);
80 if (coda_inode_cachep == NULL)
81 return -ENOMEM;
82 return 0;
83 }
84
coda_destroy_inodecache(void)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
coda_remount(struct super_block * sb,int * flags,char * data)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
get_device_index(struct coda_mount_data * data)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
coda_fill_super(struct super_block * sb,void * data,int silent)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
coda_put_super(struct super_block * sb)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
coda_evict_inode(struct inode * inode)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
coda_getattr(struct vfsmount * mnt,struct dentry * dentry,struct kstat * stat)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
coda_setattr(struct dentry * de,struct iattr * iattr)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(inode);
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
coda_statfs(struct dentry * dentry,struct kstatfs * buf)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
coda_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)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