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 <net/9p/9p.h>
24 #include <net/9p/client.h>
25
26 #include "v9fs.h"
27 #include "v9fs_vfs.h"
28 #include "fid.h"
29 #include "xattr.h"
30 #include "acl.h"
31
32 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
33
34 /**
35 * v9fs_set_super - set the superblock
36 * @s: super block
37 * @data: file system specific data
38 *
39 */
40
v9fs_set_super(struct super_block * s,void * data)41 static int v9fs_set_super(struct super_block *s, void *data)
42 {
43 s->s_fs_info = data;
44 return set_anon_super(s, data);
45 }
46
47 /**
48 * v9fs_fill_super - populate superblock with info
49 * @sb: superblock
50 * @v9ses: session information
51 * @flags: flags propagated from v9fs_mount()
52 *
53 */
54
55 static int
v9fs_fill_super(struct super_block * sb,struct v9fs_session_info * v9ses,int flags)56 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
57 int flags)
58 {
59 int ret;
60
61 sb->s_maxbytes = MAX_LFS_FILESIZE;
62 sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
63 sb->s_blocksize = 1 << sb->s_blocksize_bits;
64 sb->s_magic = V9FS_MAGIC;
65 if (v9fs_proto_dotl(v9ses)) {
66 sb->s_op = &v9fs_super_ops_dotl;
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 | SB_DIRSYNC;
88 if (!v9ses->cache)
89 sb->s_flags |= SB_SYNCHRONOUS;
90
91 #ifdef CONFIG_9P_FS_POSIX_ACL
92 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)
93 sb->s_flags |= SB_POSIXACL;
94 #endif
95
96 return 0;
97 }
98
99 /**
100 * v9fs_mount - mount a superblock
101 * @fs_type: file system type
102 * @flags: mount flags
103 * @dev_name: device name that was mounted
104 * @data: mount options
105 *
106 */
107
v9fs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)108 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
109 const char *dev_name, void *data)
110 {
111 struct super_block *sb = NULL;
112 struct inode *inode = NULL;
113 struct dentry *root = NULL;
114 struct v9fs_session_info *v9ses = NULL;
115 umode_t mode = 0777 | S_ISVTX;
116 struct p9_fid *fid;
117 int retval = 0;
118
119 p9_debug(P9_DEBUG_VFS, "\n");
120
121 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
122 if (!v9ses)
123 return ERR_PTR(-ENOMEM);
124
125 fid = v9fs_session_init(v9ses, dev_name, data);
126 if (IS_ERR(fid)) {
127 retval = PTR_ERR(fid);
128 goto free_session;
129 }
130
131 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses);
132 if (IS_ERR(sb)) {
133 retval = PTR_ERR(sb);
134 goto clunk_fid;
135 }
136 retval = v9fs_fill_super(sb, v9ses, flags);
137 if (retval)
138 goto release_sb;
139
140 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
141 sb->s_d_op = &v9fs_cached_dentry_operations;
142 else
143 sb->s_d_op = &v9fs_dentry_operations;
144
145 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0);
146 if (IS_ERR(inode)) {
147 retval = PTR_ERR(inode);
148 goto release_sb;
149 }
150
151 root = d_make_root(inode);
152 if (!root) {
153 retval = -ENOMEM;
154 goto release_sb;
155 }
156 sb->s_root = root;
157 if (v9fs_proto_dotl(v9ses)) {
158 struct p9_stat_dotl *st = NULL;
159
160 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
161 if (IS_ERR(st)) {
162 retval = PTR_ERR(st);
163 goto release_sb;
164 }
165 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
166 v9fs_stat2inode_dotl(st, d_inode(root), 0);
167 kfree(st);
168 } else {
169 struct p9_wstat *st = NULL;
170
171 st = p9_client_stat(fid);
172 if (IS_ERR(st)) {
173 retval = PTR_ERR(st);
174 goto release_sb;
175 }
176
177 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
178 v9fs_stat2inode(st, d_inode(root), sb, 0);
179
180 p9stat_free(st);
181 kfree(st);
182 }
183 retval = v9fs_get_acl(inode, fid);
184 if (retval)
185 goto release_sb;
186 v9fs_fid_add(root, fid);
187
188 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
189 return dget(sb->s_root);
190
191 clunk_fid:
192 p9_client_clunk(fid);
193 v9fs_session_close(v9ses);
194 free_session:
195 kfree(v9ses);
196 return ERR_PTR(retval);
197
198 release_sb:
199 /*
200 * we will do the session_close and root dentry release
201 * in the below call. But we need to clunk fid, because we haven't
202 * attached the fid to dentry so it won't get clunked
203 * automatically.
204 */
205 p9_client_clunk(fid);
206 deactivate_locked_super(sb);
207 return ERR_PTR(retval);
208 }
209
210 /**
211 * v9fs_kill_super - Kill Superblock
212 * @s: superblock
213 *
214 */
215
v9fs_kill_super(struct super_block * s)216 static void v9fs_kill_super(struct super_block *s)
217 {
218 struct v9fs_session_info *v9ses = s->s_fs_info;
219
220 p9_debug(P9_DEBUG_VFS, " %p\n", s);
221
222 kill_anon_super(s);
223
224 v9fs_session_cancel(v9ses);
225 v9fs_session_close(v9ses);
226 kfree(v9ses);
227 s->s_fs_info = NULL;
228 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n");
229 }
230
231 static void
v9fs_umount_begin(struct super_block * sb)232 v9fs_umount_begin(struct super_block *sb)
233 {
234 struct v9fs_session_info *v9ses;
235
236 v9ses = sb->s_fs_info;
237 v9fs_session_begin_cancel(v9ses);
238 }
239
v9fs_statfs(struct dentry * dentry,struct kstatfs * buf)240 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
241 {
242 struct v9fs_session_info *v9ses;
243 struct p9_fid *fid;
244 struct p9_rstatfs rs;
245 int res;
246
247 fid = v9fs_fid_lookup(dentry);
248 if (IS_ERR(fid)) {
249 res = PTR_ERR(fid);
250 goto done;
251 }
252
253 v9ses = v9fs_dentry2v9ses(dentry);
254 if (v9fs_proto_dotl(v9ses)) {
255 res = p9_client_statfs(fid, &rs);
256 if (res == 0) {
257 buf->f_type = rs.type;
258 buf->f_bsize = rs.bsize;
259 buf->f_blocks = rs.blocks;
260 buf->f_bfree = rs.bfree;
261 buf->f_bavail = rs.bavail;
262 buf->f_files = rs.files;
263 buf->f_ffree = rs.ffree;
264 buf->f_fsid = u64_to_fsid(rs.fsid);
265 buf->f_namelen = rs.namelen;
266 }
267 if (res != -ENOSYS)
268 goto done;
269 }
270 res = simple_statfs(dentry, buf);
271 done:
272 p9_client_clunk(fid);
273 return res;
274 }
275
v9fs_drop_inode(struct inode * inode)276 static int v9fs_drop_inode(struct inode *inode)
277 {
278 struct v9fs_session_info *v9ses;
279
280 v9ses = v9fs_inode2v9ses(inode);
281 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
282 return generic_drop_inode(inode);
283 /*
284 * in case of non cached mode always drop the
285 * inode because we want the inode attribute
286 * to always match that on the server.
287 */
288 return 1;
289 }
290
v9fs_write_inode(struct inode * inode,struct writeback_control * wbc)291 static int v9fs_write_inode(struct inode *inode,
292 struct writeback_control *wbc)
293 {
294 int ret;
295 struct p9_wstat wstat;
296 struct v9fs_inode *v9inode;
297 /*
298 * send an fsync request to server irrespective of
299 * wbc->sync_mode.
300 */
301 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
302 v9inode = V9FS_I(inode);
303 if (!v9inode->writeback_fid)
304 return 0;
305 v9fs_blank_wstat(&wstat);
306
307 ret = p9_client_wstat(v9inode->writeback_fid, &wstat);
308 if (ret < 0) {
309 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
310 return ret;
311 }
312 return 0;
313 }
314
v9fs_write_inode_dotl(struct inode * inode,struct writeback_control * wbc)315 static int v9fs_write_inode_dotl(struct inode *inode,
316 struct writeback_control *wbc)
317 {
318 int ret;
319 struct v9fs_inode *v9inode;
320 /*
321 * send an fsync request to server irrespective of
322 * wbc->sync_mode.
323 */
324 v9inode = V9FS_I(inode);
325 p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n",
326 __func__, inode, v9inode->writeback_fid);
327 if (!v9inode->writeback_fid)
328 return 0;
329
330 ret = p9_client_fsync(v9inode->writeback_fid, 0);
331 if (ret < 0) {
332 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
333 return ret;
334 }
335 return 0;
336 }
337
338 static const struct super_operations v9fs_super_ops = {
339 .alloc_inode = v9fs_alloc_inode,
340 .free_inode = v9fs_free_inode,
341 .statfs = simple_statfs,
342 .evict_inode = v9fs_evict_inode,
343 .show_options = v9fs_show_options,
344 .umount_begin = v9fs_umount_begin,
345 .write_inode = v9fs_write_inode,
346 };
347
348 static const struct super_operations v9fs_super_ops_dotl = {
349 .alloc_inode = v9fs_alloc_inode,
350 .free_inode = v9fs_free_inode,
351 .statfs = v9fs_statfs,
352 .drop_inode = v9fs_drop_inode,
353 .evict_inode = v9fs_evict_inode,
354 .show_options = v9fs_show_options,
355 .umount_begin = v9fs_umount_begin,
356 .write_inode = v9fs_write_inode_dotl,
357 };
358
359 struct file_system_type v9fs_fs_type = {
360 .name = "9p",
361 .mount = v9fs_mount,
362 .kill_sb = v9fs_kill_super,
363 .owner = THIS_MODULE,
364 .fs_flags = FS_RENAME_DOES_D_MOVE,
365 };
366 MODULE_ALIAS_FS("9p");
367