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/pagemap.h> |
16 | #include <linux/mount.h> |
17 | #include <linux/sched.h> |
18 | #include <linux/slab.h> |
19 | #include <linux/statfs.h> |
20 | #include <linux/magic.h> |
21 | #include <linux/fscache.h> |
22 | #include <net/9p/9p.h> |
23 | #include <net/9p/client.h> |
24 | |
25 | #include "v9fs.h" |
26 | #include "v9fs_vfs.h" |
27 | #include "fid.h" |
28 | #include "xattr.h" |
29 | #include "acl.h" |
30 | |
31 | static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; |
32 | |
33 | /** |
34 | * v9fs_set_super - set the superblock |
35 | * @s: super block |
36 | * @data: file system specific data |
37 | * |
38 | */ |
39 | |
40 | static int v9fs_set_super(struct super_block *s, void *data) |
41 | { |
42 | s->s_fs_info = data; |
43 | return set_anon_super(s, data); |
44 | } |
45 | |
46 | /** |
47 | * v9fs_fill_super - populate superblock with info |
48 | * @sb: superblock |
49 | * @v9ses: session information |
50 | * @flags: flags propagated from v9fs_mount() |
51 | * |
52 | */ |
53 | |
54 | static int |
55 | v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, |
56 | int flags) |
57 | { |
58 | int ret; |
59 | |
60 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
61 | sb->s_blocksize_bits = fls(x: v9ses->maxdata - 1); |
62 | sb->s_blocksize = 1 << sb->s_blocksize_bits; |
63 | sb->s_magic = V9FS_MAGIC; |
64 | if (v9fs_proto_dotl(v9ses)) { |
65 | sb->s_op = &v9fs_super_ops_dotl; |
66 | if (!(v9ses->flags & V9FS_NO_XATTR)) |
67 | sb->s_xattr = v9fs_xattr_handlers; |
68 | } else { |
69 | sb->s_op = &v9fs_super_ops; |
70 | sb->s_time_max = U32_MAX; |
71 | } |
72 | |
73 | sb->s_time_min = 0; |
74 | |
75 | ret = super_setup_bdi(sb); |
76 | if (ret) |
77 | return ret; |
78 | |
79 | if (!v9ses->cache) { |
80 | sb->s_bdi->ra_pages = 0; |
81 | sb->s_bdi->io_pages = 0; |
82 | } else { |
83 | sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT; |
84 | sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT; |
85 | } |
86 | |
87 | sb->s_flags |= SB_ACTIVE; |
88 | |
89 | #ifdef CONFIG_9P_FS_POSIX_ACL |
90 | if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) |
91 | sb->s_flags |= SB_POSIXACL; |
92 | #endif |
93 | |
94 | return 0; |
95 | } |
96 | |
97 | /** |
98 | * v9fs_mount - mount a superblock |
99 | * @fs_type: file system type |
100 | * @flags: mount flags |
101 | * @dev_name: device name that was mounted |
102 | * @data: mount options |
103 | * |
104 | */ |
105 | |
106 | static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, |
107 | const char *dev_name, void *data) |
108 | { |
109 | struct super_block *sb = NULL; |
110 | struct inode *inode = NULL; |
111 | struct dentry *root = NULL; |
112 | struct v9fs_session_info *v9ses = NULL; |
113 | umode_t mode = 0777 | S_ISVTX; |
114 | struct p9_fid *fid; |
115 | int retval = 0; |
116 | |
117 | p9_debug(P9_DEBUG_VFS, "\n" ); |
118 | |
119 | v9ses = kzalloc(size: sizeof(struct v9fs_session_info), GFP_KERNEL); |
120 | if (!v9ses) |
121 | return ERR_PTR(error: -ENOMEM); |
122 | |
123 | fid = v9fs_session_init(v9ses, dev_name, data); |
124 | if (IS_ERR(ptr: fid)) { |
125 | retval = PTR_ERR(ptr: fid); |
126 | goto free_session; |
127 | } |
128 | |
129 | sb = sget(type: fs_type, NULL, set: v9fs_set_super, flags, data: v9ses); |
130 | if (IS_ERR(ptr: sb)) { |
131 | retval = PTR_ERR(ptr: sb); |
132 | goto clunk_fid; |
133 | } |
134 | retval = v9fs_fill_super(sb, v9ses, flags); |
135 | if (retval) |
136 | goto release_sb; |
137 | |
138 | if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) |
139 | sb->s_d_op = &v9fs_cached_dentry_operations; |
140 | else |
141 | sb->s_d_op = &v9fs_dentry_operations; |
142 | |
143 | inode = v9fs_get_inode(sb, S_IFDIR | mode, rdev: 0); |
144 | if (IS_ERR(ptr: inode)) { |
145 | retval = PTR_ERR(ptr: inode); |
146 | goto release_sb; |
147 | } |
148 | |
149 | root = d_make_root(inode); |
150 | if (!root) { |
151 | retval = -ENOMEM; |
152 | goto release_sb; |
153 | } |
154 | sb->s_root = root; |
155 | if (v9fs_proto_dotl(v9ses)) { |
156 | struct p9_stat_dotl *st = NULL; |
157 | |
158 | st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); |
159 | if (IS_ERR(ptr: st)) { |
160 | retval = PTR_ERR(ptr: st); |
161 | goto release_sb; |
162 | } |
163 | d_inode(dentry: root)->i_ino = v9fs_qid2ino(qid: &st->qid); |
164 | v9fs_stat2inode_dotl(stat: st, inode: d_inode(dentry: root), flags: 0); |
165 | kfree(objp: st); |
166 | } else { |
167 | struct p9_wstat *st = NULL; |
168 | |
169 | st = p9_client_stat(fid); |
170 | if (IS_ERR(ptr: st)) { |
171 | retval = PTR_ERR(ptr: st); |
172 | goto release_sb; |
173 | } |
174 | |
175 | d_inode(dentry: root)->i_ino = v9fs_qid2ino(qid: &st->qid); |
176 | v9fs_stat2inode(stat: st, inode: d_inode(dentry: root), sb, flags: 0); |
177 | |
178 | p9stat_free(stbuf: st); |
179 | kfree(objp: st); |
180 | } |
181 | retval = v9fs_get_acl(inode, fid); |
182 | if (retval) |
183 | goto release_sb; |
184 | v9fs_fid_add(dentry: root, fid: &fid); |
185 | |
186 | p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n" ); |
187 | return dget(dentry: sb->s_root); |
188 | |
189 | clunk_fid: |
190 | p9_fid_put(fid); |
191 | v9fs_session_close(v9ses); |
192 | free_session: |
193 | kfree(objp: v9ses); |
194 | return ERR_PTR(error: retval); |
195 | |
196 | release_sb: |
197 | /* |
198 | * we will do the session_close and root dentry release |
199 | * in the below call. But we need to clunk fid, because we haven't |
200 | * attached the fid to dentry so it won't get clunked |
201 | * automatically. |
202 | */ |
203 | p9_fid_put(fid); |
204 | deactivate_locked_super(sb); |
205 | return ERR_PTR(error: retval); |
206 | } |
207 | |
208 | /** |
209 | * v9fs_kill_super - Kill Superblock |
210 | * @s: superblock |
211 | * |
212 | */ |
213 | |
214 | static void v9fs_kill_super(struct super_block *s) |
215 | { |
216 | struct v9fs_session_info *v9ses = s->s_fs_info; |
217 | |
218 | p9_debug(P9_DEBUG_VFS, " %p\n" , s); |
219 | |
220 | kill_anon_super(sb: s); |
221 | |
222 | v9fs_session_cancel(v9ses); |
223 | v9fs_session_close(v9ses); |
224 | kfree(objp: v9ses); |
225 | s->s_fs_info = NULL; |
226 | p9_debug(P9_DEBUG_VFS, "exiting kill_super\n" ); |
227 | } |
228 | |
229 | static void |
230 | v9fs_umount_begin(struct super_block *sb) |
231 | { |
232 | struct v9fs_session_info *v9ses; |
233 | |
234 | v9ses = sb->s_fs_info; |
235 | v9fs_session_begin_cancel(v9ses); |
236 | } |
237 | |
238 | static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) |
239 | { |
240 | struct v9fs_session_info *v9ses; |
241 | struct p9_fid *fid; |
242 | struct p9_rstatfs rs; |
243 | int res; |
244 | |
245 | fid = v9fs_fid_lookup(dentry); |
246 | if (IS_ERR(ptr: fid)) { |
247 | res = PTR_ERR(ptr: fid); |
248 | goto done; |
249 | } |
250 | |
251 | v9ses = v9fs_dentry2v9ses(dentry); |
252 | if (v9fs_proto_dotl(v9ses)) { |
253 | res = p9_client_statfs(fid, sb: &rs); |
254 | if (res == 0) { |
255 | buf->f_type = rs.type; |
256 | buf->f_bsize = rs.bsize; |
257 | buf->f_blocks = rs.blocks; |
258 | buf->f_bfree = rs.bfree; |
259 | buf->f_bavail = rs.bavail; |
260 | buf->f_files = rs.files; |
261 | buf->f_ffree = rs.ffree; |
262 | buf->f_fsid = u64_to_fsid(v: rs.fsid); |
263 | buf->f_namelen = rs.namelen; |
264 | } |
265 | if (res != -ENOSYS) |
266 | goto done; |
267 | } |
268 | res = simple_statfs(dentry, buf); |
269 | done: |
270 | p9_fid_put(fid); |
271 | return res; |
272 | } |
273 | |
274 | static int v9fs_drop_inode(struct inode *inode) |
275 | { |
276 | struct v9fs_session_info *v9ses; |
277 | |
278 | v9ses = v9fs_inode2v9ses(inode); |
279 | if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) |
280 | return generic_drop_inode(inode); |
281 | /* |
282 | * in case of non cached mode always drop the |
283 | * inode because we want the inode attribute |
284 | * to always match that on the server. |
285 | */ |
286 | return 1; |
287 | } |
288 | |
289 | static int v9fs_write_inode(struct inode *inode, |
290 | struct writeback_control *wbc) |
291 | { |
292 | struct v9fs_inode *v9inode; |
293 | |
294 | /* |
295 | * send an fsync request to server irrespective of |
296 | * wbc->sync_mode. |
297 | */ |
298 | p9_debug(P9_DEBUG_VFS, "%s: inode %p\n" , __func__, inode); |
299 | |
300 | v9inode = V9FS_I(inode); |
301 | fscache_unpin_writeback(wbc, cookie: v9fs_inode_cookie(v9inode)); |
302 | |
303 | return 0; |
304 | } |
305 | |
306 | static int v9fs_write_inode_dotl(struct inode *inode, |
307 | struct writeback_control *wbc) |
308 | { |
309 | struct v9fs_inode *v9inode; |
310 | |
311 | v9inode = V9FS_I(inode); |
312 | p9_debug(P9_DEBUG_VFS, "%s: inode %p\n" , __func__, inode); |
313 | |
314 | fscache_unpin_writeback(wbc, cookie: v9fs_inode_cookie(v9inode)); |
315 | |
316 | return 0; |
317 | } |
318 | |
319 | static const struct super_operations v9fs_super_ops = { |
320 | .alloc_inode = v9fs_alloc_inode, |
321 | .free_inode = v9fs_free_inode, |
322 | .statfs = simple_statfs, |
323 | .evict_inode = v9fs_evict_inode, |
324 | .show_options = v9fs_show_options, |
325 | .umount_begin = v9fs_umount_begin, |
326 | .write_inode = v9fs_write_inode, |
327 | }; |
328 | |
329 | static const struct super_operations v9fs_super_ops_dotl = { |
330 | .alloc_inode = v9fs_alloc_inode, |
331 | .free_inode = v9fs_free_inode, |
332 | .statfs = v9fs_statfs, |
333 | .drop_inode = v9fs_drop_inode, |
334 | .evict_inode = v9fs_evict_inode, |
335 | .show_options = v9fs_show_options, |
336 | .umount_begin = v9fs_umount_begin, |
337 | .write_inode = v9fs_write_inode_dotl, |
338 | }; |
339 | |
340 | struct file_system_type v9fs_fs_type = { |
341 | .name = "9p" , |
342 | .mount = v9fs_mount, |
343 | .kill_sb = v9fs_kill_super, |
344 | .owner = THIS_MODULE, |
345 | .fs_flags = FS_RENAME_DOES_D_MOVE, |
346 | }; |
347 | MODULE_ALIAS_FS("9p" ); |
348 | |