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 <linux/fs_context.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
v9fs_fill_super(struct super_block * sb)34 static int v9fs_fill_super(struct super_block *sb)
35 {
36 int ret;
37 struct v9fs_session_info *v9ses = v9ses = sb->s_fs_info;
38
39 sb->s_maxbytes = MAX_LFS_FILESIZE;
40 sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
41 sb->s_blocksize = 1 << sb->s_blocksize_bits;
42 sb->s_magic = V9FS_MAGIC;
43 if (v9fs_proto_dotl(v9ses)) {
44 sb->s_op = &v9fs_super_ops_dotl;
45 if (!(v9ses->flags & V9FS_NO_XATTR))
46 sb->s_xattr = v9fs_xattr_handlers;
47 } else {
48 sb->s_op = &v9fs_super_ops;
49 sb->s_time_max = U32_MAX;
50 }
51
52 sb->s_time_min = 0;
53
54 ret = super_setup_bdi(sb);
55 if (ret)
56 return ret;
57
58 if (!v9ses->cache) {
59 sb->s_bdi->ra_pages = 0;
60 sb->s_bdi->io_pages = 0;
61 } else {
62 sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT;
63 sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT;
64 }
65
66 sb->s_flags |= SB_ACTIVE;
67
68 #ifdef CONFIG_9P_FS_POSIX_ACL
69 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)
70 sb->s_flags |= SB_POSIXACL;
71 #endif
72
73 return 0;
74 }
75
76 /**
77 * v9fs_get_tree - create the mountable root and superblock
78 * @fc: the filesystem context
79 *
80 */
81
v9fs_get_tree(struct fs_context * fc)82 static int v9fs_get_tree(struct fs_context *fc)
83 {
84 struct super_block *sb = NULL;
85 struct inode *inode = NULL;
86 struct dentry *root = NULL;
87 struct v9fs_session_info *v9ses = NULL;
88 struct p9_fid *fid;
89 int retval = 0;
90
91 p9_debug(P9_DEBUG_VFS, "\n");
92
93 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
94 if (!v9ses)
95 return -ENOMEM;
96
97 fid = v9fs_session_init(v9ses, fc);
98 if (IS_ERR(fid)) {
99 retval = PTR_ERR(fid);
100 goto free_session;
101 }
102
103 fc->s_fs_info = v9ses;
104 sb = sget_fc(fc, NULL, set_anon_super_fc);
105 if (IS_ERR(sb)) {
106 retval = PTR_ERR(sb);
107 goto clunk_fid;
108 }
109 retval = v9fs_fill_super(sb);
110 if (retval)
111 goto release_sb;
112
113 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
114 set_default_d_op(sb, &v9fs_cached_dentry_operations);
115 } else {
116 set_default_d_op(sb, &v9fs_dentry_operations);
117 sb->s_d_flags |= DCACHE_DONTCACHE;
118 }
119
120 inode = v9fs_get_new_inode_from_fid(v9ses, fid, sb);
121 if (IS_ERR(inode)) {
122 retval = PTR_ERR(inode);
123 goto release_sb;
124 }
125
126 root = d_make_root(inode);
127 if (!root) {
128 retval = -ENOMEM;
129 goto release_sb;
130 }
131 sb->s_root = root;
132 retval = v9fs_get_acl(inode, fid);
133 if (retval)
134 goto release_sb;
135 v9fs_fid_add(root, &fid);
136
137 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
138 fc->root = dget(sb->s_root);
139 return 0;
140
141 clunk_fid:
142 p9_fid_put(fid);
143 v9fs_session_close(v9ses);
144 free_session:
145 kfree(v9ses);
146 return retval;
147
148 release_sb:
149 /*
150 * we will do the session_close and root dentry release
151 * in the below call. But we need to clunk fid, because we haven't
152 * attached the fid to dentry so it won't get clunked
153 * automatically.
154 */
155 p9_fid_put(fid);
156 deactivate_locked_super(sb);
157 return retval;
158 }
159
160 /**
161 * v9fs_kill_super - Kill Superblock
162 * @s: superblock
163 *
164 */
165
v9fs_kill_super(struct super_block * s)166 static void v9fs_kill_super(struct super_block *s)
167 {
168 struct v9fs_session_info *v9ses = s->s_fs_info;
169
170 p9_debug(P9_DEBUG_VFS, " %p\n", s);
171
172 kill_anon_super(s);
173
174 v9fs_session_cancel(v9ses);
175 v9fs_session_close(v9ses);
176 kfree(v9ses);
177 s->s_fs_info = NULL;
178 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n");
179 }
180
181 static void
v9fs_umount_begin(struct super_block * sb)182 v9fs_umount_begin(struct super_block *sb)
183 {
184 struct v9fs_session_info *v9ses;
185
186 v9ses = sb->s_fs_info;
187 v9fs_session_begin_cancel(v9ses);
188 }
189
v9fs_statfs(struct dentry * dentry,struct kstatfs * buf)190 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
191 {
192 struct v9fs_session_info *v9ses;
193 struct p9_fid *fid;
194 struct p9_rstatfs rs;
195 int res;
196
197 fid = v9fs_fid_lookup(dentry);
198 if (IS_ERR(fid)) {
199 res = PTR_ERR(fid);
200 goto done;
201 }
202
203 v9ses = v9fs_dentry2v9ses(dentry);
204 if (v9fs_proto_dotl(v9ses)) {
205 res = p9_client_statfs(fid, &rs);
206 if (res == 0) {
207 buf->f_type = rs.type;
208 buf->f_bsize = rs.bsize;
209 buf->f_blocks = rs.blocks;
210 buf->f_bfree = rs.bfree;
211 buf->f_bavail = rs.bavail;
212 buf->f_files = rs.files;
213 buf->f_ffree = rs.ffree;
214 buf->f_fsid = u64_to_fsid(rs.fsid);
215 buf->f_namelen = rs.namelen;
216 }
217 if (res != -ENOSYS)
218 goto done;
219 }
220 res = simple_statfs(dentry, buf);
221 done:
222 p9_fid_put(fid);
223 return res;
224 }
225
v9fs_drop_inode(struct inode * inode)226 static int v9fs_drop_inode(struct inode *inode)
227 {
228 struct v9fs_session_info *v9ses;
229
230 v9ses = v9fs_inode2v9ses(inode);
231 if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
232 return inode_generic_drop(inode);
233 /*
234 * in case of non cached mode always drop the
235 * inode because we want the inode attribute
236 * to always match that on the server.
237 */
238 return 1;
239 }
240
v9fs_write_inode(struct inode * inode,struct writeback_control * wbc)241 static int v9fs_write_inode(struct inode *inode,
242 struct writeback_control *wbc)
243 {
244 /*
245 * send an fsync request to server irrespective of
246 * wbc->sync_mode.
247 */
248 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
249 return netfs_unpin_writeback(inode, wbc);
250 }
251
v9fs_write_inode_dotl(struct inode * inode,struct writeback_control * wbc)252 static int v9fs_write_inode_dotl(struct inode *inode,
253 struct writeback_control *wbc)
254 {
255
256 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
257
258 return netfs_unpin_writeback(inode, wbc);
259 }
260
261 static const struct super_operations v9fs_super_ops = {
262 .alloc_inode = v9fs_alloc_inode,
263 .free_inode = v9fs_free_inode,
264 .statfs = simple_statfs,
265 .drop_inode = v9fs_drop_inode,
266 .evict_inode = v9fs_evict_inode,
267 .show_options = v9fs_show_options,
268 .umount_begin = v9fs_umount_begin,
269 .write_inode = v9fs_write_inode,
270 };
271
272 static const struct super_operations v9fs_super_ops_dotl = {
273 .alloc_inode = v9fs_alloc_inode,
274 .free_inode = v9fs_free_inode,
275 .statfs = v9fs_statfs,
276 .drop_inode = v9fs_drop_inode,
277 .evict_inode = v9fs_evict_inode,
278 .show_options = v9fs_show_options,
279 .umount_begin = v9fs_umount_begin,
280 .write_inode = v9fs_write_inode_dotl,
281 };
282
v9fs_free_fc(struct fs_context * fc)283 static void v9fs_free_fc(struct fs_context *fc)
284 {
285 struct v9fs_context *ctx = fc->fs_private;
286
287 if (!ctx)
288 return;
289
290 /* These should be NULL by now but guard against leaks */
291 kfree(ctx->session_opts.uname);
292 kfree(ctx->session_opts.aname);
293 #ifdef CONFIG_9P_FSCACHE
294 kfree(ctx->session_opts.cachetag);
295 #endif
296 if (ctx->client_opts.trans_mod)
297 v9fs_put_trans(ctx->client_opts.trans_mod);
298 kfree(ctx);
299 }
300
301 static const struct fs_context_operations v9fs_context_ops = {
302 .parse_param = v9fs_parse_param,
303 .get_tree = v9fs_get_tree,
304 .free = v9fs_free_fc,
305 };
306
v9fs_init_fs_context(struct fs_context * fc)307 static int v9fs_init_fs_context(struct fs_context *fc)
308 {
309 struct v9fs_context *ctx;
310
311 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
312 if (!ctx)
313 return -ENOMEM;
314
315 /* initialize core options */
316 ctx->session_opts.afid = ~0;
317 ctx->session_opts.cache = CACHE_NONE;
318 ctx->session_opts.session_lock_timeout = P9_LOCK_TIMEOUT;
319 ctx->session_opts.uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
320 if (!ctx->session_opts.uname)
321 goto error;
322
323 ctx->session_opts.aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
324 if (!ctx->session_opts.aname)
325 goto error;
326
327 ctx->session_opts.uid = INVALID_UID;
328 ctx->session_opts.dfltuid = V9FS_DEFUID;
329 ctx->session_opts.dfltgid = V9FS_DEFGID;
330
331 /* initialize client options */
332 ctx->client_opts.proto_version = p9_proto_2000L;
333 ctx->client_opts.msize = DEFAULT_MSIZE;
334
335 /* initialize fd transport options */
336 ctx->fd_opts.port = P9_FD_PORT;
337 ctx->fd_opts.rfd = ~0;
338 ctx->fd_opts.wfd = ~0;
339 ctx->fd_opts.privport = false;
340
341 /* initialize rdma transport options */
342 ctx->rdma_opts.port = P9_RDMA_PORT;
343 ctx->rdma_opts.sq_depth = P9_RDMA_SQ_DEPTH;
344 ctx->rdma_opts.rq_depth = P9_RDMA_RQ_DEPTH;
345 ctx->rdma_opts.timeout = P9_RDMA_TIMEOUT;
346 ctx->rdma_opts.privport = false;
347
348 fc->ops = &v9fs_context_ops;
349 fc->fs_private = ctx;
350
351 return 0;
352 error:
353 fc->need_free = 1;
354 return -ENOMEM;
355 }
356
357 struct file_system_type v9fs_fs_type = {
358 .name = "9p",
359 .kill_sb = v9fs_kill_super,
360 .owner = THIS_MODULE,
361 .fs_flags = FS_RENAME_DOES_D_MOVE,
362 .init_fs_context = v9fs_init_fs_context,
363 .parameters = v9fs_param_spec,
364 };
365 MODULE_ALIAS_FS("9p");
366