1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Super block/filesystem wide operations
4 *
5 * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
6 * Michael Callahan <callahan@maths.ox.ac.uk>
7 *
8 * Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu>
9 * Copyright (C) Carnegie Mellon University
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/string.h>
16 #include <linux/stat.h>
17 #include <linux/errno.h>
18 #include <linux/unistd.h>
19 #include <linux/mutex.h>
20 #include <linux/spinlock.h>
21 #include <linux/file.h>
22 #include <linux/vfs.h>
23 #include <linux/slab.h>
24 #include <linux/pid_namespace.h>
25 #include <linux/uaccess.h>
26 #include <linux/fs.h>
27 #include <linux/vmalloc.h>
28
29 #include <linux/coda.h>
30 #include "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 = GLOBAL_ROOT_UID;
52 ei->c_cached_perm = 0;
53 spin_lock_init(&ei->c_lock);
54 return &ei->vfs_inode;
55 }
56
coda_free_inode(struct inode * inode)57 static void coda_free_inode(struct inode *inode)
58 {
59 kmem_cache_free(coda_inode_cachep, ITOC(inode));
60 }
61
init_once(void * foo)62 static void init_once(void *foo)
63 {
64 struct coda_inode_info *ei = (struct coda_inode_info *) foo;
65
66 inode_init_once(&ei->vfs_inode);
67 }
68
coda_init_inodecache(void)69 int __init coda_init_inodecache(void)
70 {
71 coda_inode_cachep = kmem_cache_create("coda_inode_cache",
72 sizeof(struct coda_inode_info), 0,
73 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
74 SLAB_ACCOUNT, init_once);
75 if (coda_inode_cachep == NULL)
76 return -ENOMEM;
77 return 0;
78 }
79
coda_destroy_inodecache(void)80 void coda_destroy_inodecache(void)
81 {
82 /*
83 * Make sure all delayed rcu free inodes are flushed before we
84 * destroy cache.
85 */
86 rcu_barrier();
87 kmem_cache_destroy(coda_inode_cachep);
88 }
89
coda_remount(struct super_block * sb,int * flags,char * data)90 static int coda_remount(struct super_block *sb, int *flags, char *data)
91 {
92 sync_filesystem(sb);
93 *flags |= SB_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 .free_inode = coda_free_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 fd f;
111 struct inode *inode;
112 int idx;
113
114 if (data == NULL) {
115 pr_warn("%s: Bad mount data\n", __func__);
116 return -1;
117 }
118
119 if (data->version != CODA_MOUNT_VERSION) {
120 pr_warn("%s: Bad mount version\n", __func__);
121 return -1;
122 }
123
124 f = fdget(data->fd);
125 if (!f.file)
126 goto Ebadf;
127 inode = file_inode(f.file);
128 if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
129 fdput(f);
130 goto Ebadf;
131 }
132
133 idx = iminor(inode);
134 fdput(f);
135
136 if (idx < 0 || idx >= MAX_CODADEVS) {
137 pr_warn("%s: Bad minor number\n", __func__);
138 return -1;
139 }
140
141 return idx;
142 Ebadf:
143 pr_warn("%s: Bad file\n", __func__);
144 return -1;
145 }
146
coda_fill_super(struct super_block * sb,void * data,int silent)147 static int coda_fill_super(struct super_block *sb, void *data, int silent)
148 {
149 struct inode *root = NULL;
150 struct venus_comm *vc;
151 struct CodaFid fid;
152 int error;
153 int idx;
154
155 if (task_active_pid_ns(current) != &init_pid_ns)
156 return -EINVAL;
157
158 idx = get_device_index((struct coda_mount_data *) data);
159
160 /* Ignore errors in data, for backward compatibility */
161 if(idx == -1)
162 idx = 0;
163
164 pr_info("%s: device index: %i\n", __func__, idx);
165
166 vc = &coda_comms[idx];
167 mutex_lock(&vc->vc_mutex);
168
169 if (!vc->vc_inuse) {
170 pr_warn("%s: No pseudo device\n", __func__);
171 error = -EINVAL;
172 goto unlock_out;
173 }
174
175 if (vc->vc_sb) {
176 pr_warn("%s: Device already mounted\n", __func__);
177 error = -EBUSY;
178 goto unlock_out;
179 }
180
181 vc->vc_sb = sb;
182 mutex_unlock(&vc->vc_mutex);
183
184 sb->s_fs_info = vc;
185 sb->s_flags |= SB_NOATIME;
186 sb->s_blocksize = 4096; /* XXXXX what do we put here?? */
187 sb->s_blocksize_bits = 12;
188 sb->s_magic = CODA_SUPER_MAGIC;
189 sb->s_op = &coda_super_operations;
190 sb->s_d_op = &coda_dentry_operations;
191 sb->s_time_gran = 1;
192 sb->s_time_min = S64_MIN;
193 sb->s_time_max = S64_MAX;
194
195 error = super_setup_bdi(sb);
196 if (error)
197 goto error;
198
199 /* get root fid from Venus: this needs the root inode */
200 error = venus_rootfid(sb, &fid);
201 if ( error ) {
202 pr_warn("%s: coda_get_rootfid failed with %d\n",
203 __func__, error);
204 goto error;
205 }
206 pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
207
208 /* make root inode */
209 root = coda_cnode_make(&fid, sb);
210 if (IS_ERR(root)) {
211 error = PTR_ERR(root);
212 pr_warn("Failure of coda_cnode_make for root: error %d\n",
213 error);
214 goto error;
215 }
216
217 pr_info("%s: rootinode is %ld dev %s\n",
218 __func__, root->i_ino, root->i_sb->s_id);
219 sb->s_root = d_make_root(root);
220 if (!sb->s_root) {
221 error = -EINVAL;
222 goto error;
223 }
224 return 0;
225
226 error:
227 mutex_lock(&vc->vc_mutex);
228 vc->vc_sb = NULL;
229 sb->s_fs_info = NULL;
230 unlock_out:
231 mutex_unlock(&vc->vc_mutex);
232 return error;
233 }
234
coda_put_super(struct super_block * sb)235 static void coda_put_super(struct super_block *sb)
236 {
237 struct venus_comm *vcp = coda_vcp(sb);
238 mutex_lock(&vcp->vc_mutex);
239 vcp->vc_sb = NULL;
240 sb->s_fs_info = NULL;
241 mutex_unlock(&vcp->vc_mutex);
242 mutex_destroy(&vcp->vc_mutex);
243
244 pr_info("Bye bye.\n");
245 }
246
coda_evict_inode(struct inode * inode)247 static void coda_evict_inode(struct inode *inode)
248 {
249 truncate_inode_pages_final(&inode->i_data);
250 clear_inode(inode);
251 coda_cache_clear_inode(inode);
252 }
253
coda_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)254 int coda_getattr(struct user_namespace *mnt_userns, const struct path *path,
255 struct kstat *stat, u32 request_mask, unsigned int flags)
256 {
257 int err = coda_revalidate_inode(d_inode(path->dentry));
258 if (!err)
259 generic_fillattr(&init_user_ns, d_inode(path->dentry), stat);
260 return err;
261 }
262
coda_setattr(struct user_namespace * mnt_userns,struct dentry * de,struct iattr * iattr)263 int coda_setattr(struct user_namespace *mnt_userns, struct dentry *de,
264 struct iattr *iattr)
265 {
266 struct inode *inode = d_inode(de);
267 struct coda_vattr vattr;
268 int error;
269
270 memset(&vattr, 0, sizeof(vattr));
271
272 inode->i_ctime = current_time(inode);
273 coda_iattr_to_vattr(iattr, &vattr);
274 vattr.va_type = C_VNON; /* cannot set type */
275
276 /* Venus is responsible for truncating the container-file!!! */
277 error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
278
279 if (!error) {
280 coda_vattr_to_iattr(inode, &vattr);
281 coda_cache_clear_inode(inode);
282 }
283 return error;
284 }
285
286 const struct inode_operations coda_file_inode_operations = {
287 .permission = coda_permission,
288 .getattr = coda_getattr,
289 .setattr = coda_setattr,
290 };
291
coda_statfs(struct dentry * dentry,struct kstatfs * buf)292 static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
293 {
294 int error;
295
296 error = venus_statfs(dentry, buf);
297
298 if (error) {
299 /* fake something like AFS does */
300 buf->f_blocks = 9000000;
301 buf->f_bfree = 9000000;
302 buf->f_bavail = 9000000;
303 buf->f_files = 9000000;
304 buf->f_ffree = 9000000;
305 }
306
307 /* and fill in the rest */
308 buf->f_type = CODA_SUPER_MAGIC;
309 buf->f_bsize = 4096;
310 buf->f_namelen = CODA_MAXNAMLEN;
311
312 return 0;
313 }
314
315 /* init_coda: used by filesystems.c to register coda */
316
coda_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)317 static struct dentry *coda_mount(struct file_system_type *fs_type,
318 int flags, const char *dev_name, void *data)
319 {
320 return mount_nodev(fs_type, flags, data, coda_fill_super);
321 }
322
323 struct file_system_type coda_fs_type = {
324 .owner = THIS_MODULE,
325 .name = "coda",
326 .mount = coda_mount,
327 .kill_sb = kill_anon_super,
328 .fs_flags = FS_BINARY_MOUNTDATA,
329 };
330 MODULE_ALIAS_FS("coda");
331
332