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