1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
5 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/errno.h>
11 #include <linux/fs.h>
12 #include <linux/file.h>
13 #include <linux/stat.h>
14 #include <linux/string.h>
15 #include <linux/inet.h>
16 #include <linux/pagemap.h>
17 #include <linux/mount.h>
18 #include <linux/idr.h>
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/statfs.h>
22 #include <linux/magic.h>
23 #include <linux/fscache.h>
24 #include <net/9p/9p.h>
25 #include <net/9p/client.h>
26
27 #include "v9fs.h"
28 #include "v9fs_vfs.h"
29 #include "fid.h"
30 #include "xattr.h"
31 #include "acl.h"
32
33 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
34
35 /**
36 * v9fs_set_super - set the superblock
37 * @s: super block
38 * @data: file system specific data
39 *
40 */
41
v9fs_set_super(struct super_block * s,void * data)42 static int v9fs_set_super(struct super_block *s, void *data)
43 {
44 s->s_fs_info = data;
45 return set_anon_super(s, data);
46 }
47
48 /**
49 * v9fs_fill_super - populate superblock with info
50 * @sb: superblock
51 * @v9ses: session information
52 * @flags: flags propagated from v9fs_mount()
53 *
54 */
55
56 static int
v9fs_fill_super(struct super_block * sb,struct v9fs_session_info * v9ses,int flags)57 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
58 int flags)
59 {
60 int ret;
61
62 sb->s_maxbytes = MAX_LFS_FILESIZE;
63 sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
64 sb->s_blocksize = 1 << sb->s_blocksize_bits;
65 sb->s_magic = V9FS_MAGIC;
66 if (v9fs_proto_dotl(v9ses)) {
67 sb->s_op = &v9fs_super_ops_dotl;
68 sb->s_xattr = v9fs_xattr_handlers;
69 } else {
70 sb->s_op = &v9fs_super_ops;
71 sb->s_time_max = U32_MAX;
72 }
73
74 sb->s_time_min = 0;
75
76 ret = super_setup_bdi(sb);
77 if (ret)
78 return ret;
79
80 if (!v9ses->cache) {
81 sb->s_bdi->ra_pages = 0;
82 sb->s_bdi->io_pages = 0;
83 } else {
84 sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT;
85 sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT;
86 }
87
88 sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
89 if (!v9ses->cache)
90 sb->s_flags |= SB_SYNCHRONOUS;
91
92 #ifdef CONFIG_9P_FS_POSIX_ACL
93 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)
94 sb->s_flags |= SB_POSIXACL;
95 #endif
96
97 return 0;
98 }
99
100 /**
101 * v9fs_mount - mount a superblock
102 * @fs_type: file system type
103 * @flags: mount flags
104 * @dev_name: device name that was mounted
105 * @data: mount options
106 *
107 */
108
v9fs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)109 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
110 const char *dev_name, void *data)
111 {
112 struct super_block *sb = NULL;
113 struct inode *inode = NULL;
114 struct dentry *root = NULL;
115 struct v9fs_session_info *v9ses = NULL;
116 umode_t mode = 0777 | S_ISVTX;
117 struct p9_fid *fid;
118 int retval = 0;
119
120 p9_debug(P9_DEBUG_VFS, "\n");
121
122 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
123 if (!v9ses)
124 return ERR_PTR(-ENOMEM);
125
126 fid = v9fs_session_init(v9ses, dev_name, data);
127 if (IS_ERR(fid)) {
128 retval = PTR_ERR(fid);
129 goto free_session;
130 }
131
132 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses);
133 if (IS_ERR(sb)) {
134 retval = PTR_ERR(sb);
135 goto clunk_fid;
136 }
137 retval = v9fs_fill_super(sb, v9ses, flags);
138 if (retval)
139 goto release_sb;
140
141 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
142 sb->s_d_op = &v9fs_cached_dentry_operations;
143 else
144 sb->s_d_op = &v9fs_dentry_operations;
145
146 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0);
147 if (IS_ERR(inode)) {
148 retval = PTR_ERR(inode);
149 goto release_sb;
150 }
151
152 root = d_make_root(inode);
153 if (!root) {
154 retval = -ENOMEM;
155 goto release_sb;
156 }
157 sb->s_root = root;
158 if (v9fs_proto_dotl(v9ses)) {
159 struct p9_stat_dotl *st = NULL;
160
161 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
162 if (IS_ERR(st)) {
163 retval = PTR_ERR(st);
164 goto release_sb;
165 }
166 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
167 v9fs_stat2inode_dotl(st, d_inode(root), 0);
168 kfree(st);
169 } else {
170 struct p9_wstat *st = NULL;
171
172 st = p9_client_stat(fid);
173 if (IS_ERR(st)) {
174 retval = PTR_ERR(st);
175 goto release_sb;
176 }
177
178 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
179 v9fs_stat2inode(st, d_inode(root), sb, 0);
180
181 p9stat_free(st);
182 kfree(st);
183 }
184 retval = v9fs_get_acl(inode, fid);
185 if (retval)
186 goto release_sb;
187 v9fs_fid_add(root, &fid);
188
189 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
190 return dget(sb->s_root);
191
192 clunk_fid:
193 p9_fid_put(fid);
194 v9fs_session_close(v9ses);
195 free_session:
196 kfree(v9ses);
197 return ERR_PTR(retval);
198
199 release_sb:
200 /*
201 * we will do the session_close and root dentry release
202 * in the below call. But we need to clunk fid, because we haven't
203 * attached the fid to dentry so it won't get clunked
204 * automatically.
205 */
206 p9_fid_put(fid);
207 deactivate_locked_super(sb);
208 return ERR_PTR(retval);
209 }
210
211 /**
212 * v9fs_kill_super - Kill Superblock
213 * @s: superblock
214 *
215 */
216
v9fs_kill_super(struct super_block * s)217 static void v9fs_kill_super(struct super_block *s)
218 {
219 struct v9fs_session_info *v9ses = s->s_fs_info;
220
221 p9_debug(P9_DEBUG_VFS, " %p\n", s);
222
223 kill_anon_super(s);
224
225 v9fs_session_cancel(v9ses);
226 v9fs_session_close(v9ses);
227 kfree(v9ses);
228 s->s_fs_info = NULL;
229 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n");
230 }
231
232 static void
v9fs_umount_begin(struct super_block * sb)233 v9fs_umount_begin(struct super_block *sb)
234 {
235 struct v9fs_session_info *v9ses;
236
237 v9ses = sb->s_fs_info;
238 v9fs_session_begin_cancel(v9ses);
239 }
240
v9fs_statfs(struct dentry * dentry,struct kstatfs * buf)241 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
242 {
243 struct v9fs_session_info *v9ses;
244 struct p9_fid *fid;
245 struct p9_rstatfs rs;
246 int res;
247
248 fid = v9fs_fid_lookup(dentry);
249 if (IS_ERR(fid)) {
250 res = PTR_ERR(fid);
251 goto done;
252 }
253
254 v9ses = v9fs_dentry2v9ses(dentry);
255 if (v9fs_proto_dotl(v9ses)) {
256 res = p9_client_statfs(fid, &rs);
257 if (res == 0) {
258 buf->f_type = rs.type;
259 buf->f_bsize = rs.bsize;
260 buf->f_blocks = rs.blocks;
261 buf->f_bfree = rs.bfree;
262 buf->f_bavail = rs.bavail;
263 buf->f_files = rs.files;
264 buf->f_ffree = rs.ffree;
265 buf->f_fsid = u64_to_fsid(rs.fsid);
266 buf->f_namelen = rs.namelen;
267 }
268 if (res != -ENOSYS)
269 goto done;
270 }
271 res = simple_statfs(dentry, buf);
272 done:
273 p9_fid_put(fid);
274 return res;
275 }
276
v9fs_drop_inode(struct inode * inode)277 static int v9fs_drop_inode(struct inode *inode)
278 {
279 struct v9fs_session_info *v9ses;
280
281 v9ses = v9fs_inode2v9ses(inode);
282 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
283 return generic_drop_inode(inode);
284 /*
285 * in case of non cached mode always drop the
286 * inode because we want the inode attribute
287 * to always match that on the server.
288 */
289 return 1;
290 }
291
v9fs_write_inode(struct inode * inode,struct writeback_control * wbc)292 static int v9fs_write_inode(struct inode *inode,
293 struct writeback_control *wbc)
294 {
295 int ret;
296 struct p9_wstat wstat;
297 struct v9fs_inode *v9inode;
298 /*
299 * send an fsync request to server irrespective of
300 * wbc->sync_mode.
301 */
302 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
303 v9inode = V9FS_I(inode);
304 if (!v9inode->writeback_fid)
305 return 0;
306 v9fs_blank_wstat(&wstat);
307
308 ret = p9_client_wstat(v9inode->writeback_fid, &wstat);
309 if (ret < 0) {
310 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
311 return ret;
312 }
313 fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode));
314 return 0;
315 }
316
v9fs_write_inode_dotl(struct inode * inode,struct writeback_control * wbc)317 static int v9fs_write_inode_dotl(struct inode *inode,
318 struct writeback_control *wbc)
319 {
320 int ret;
321 struct v9fs_inode *v9inode;
322 /*
323 * send an fsync request to server irrespective of
324 * wbc->sync_mode.
325 */
326 v9inode = V9FS_I(inode);
327 p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n",
328 __func__, inode, v9inode->writeback_fid);
329 if (!v9inode->writeback_fid)
330 return 0;
331
332 ret = p9_client_fsync(v9inode->writeback_fid, 0);
333 if (ret < 0) {
334 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
335 return ret;
336 }
337 fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode));
338 return 0;
339 }
340
341 static const struct super_operations v9fs_super_ops = {
342 .alloc_inode = v9fs_alloc_inode,
343 .free_inode = v9fs_free_inode,
344 .statfs = simple_statfs,
345 .evict_inode = v9fs_evict_inode,
346 .show_options = v9fs_show_options,
347 .umount_begin = v9fs_umount_begin,
348 .write_inode = v9fs_write_inode,
349 };
350
351 static const struct super_operations v9fs_super_ops_dotl = {
352 .alloc_inode = v9fs_alloc_inode,
353 .free_inode = v9fs_free_inode,
354 .statfs = v9fs_statfs,
355 .drop_inode = v9fs_drop_inode,
356 .evict_inode = v9fs_evict_inode,
357 .show_options = v9fs_show_options,
358 .umount_begin = v9fs_umount_begin,
359 .write_inode = v9fs_write_inode_dotl,
360 };
361
362 struct file_system_type v9fs_fs_type = {
363 .name = "9p",
364 .mount = v9fs_mount,
365 .kill_sb = v9fs_kill_super,
366 .owner = THIS_MODULE,
367 .fs_flags = FS_RENAME_DOES_D_MOVE,
368 };
369 MODULE_ALIAS_FS("9p");
370