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
31static 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
40static 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
54static int
55v9fs_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
106static 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 struct p9_fid *fid;
114 int retval = 0;
115
116 p9_debug(P9_DEBUG_VFS, "\n");
117
118 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
119 if (!v9ses)
120 return ERR_PTR(error: -ENOMEM);
121
122 fid = v9fs_session_init(v9ses, dev_name, data);
123 if (IS_ERR(ptr: fid)) {
124 retval = PTR_ERR(ptr: fid);
125 goto free_session;
126 }
127
128 sb = sget(type: fs_type, NULL, set: v9fs_set_super, flags, data: v9ses);
129 if (IS_ERR(ptr: sb)) {
130 retval = PTR_ERR(ptr: sb);
131 goto clunk_fid;
132 }
133 retval = v9fs_fill_super(sb, v9ses, flags);
134 if (retval)
135 goto release_sb;
136
137 if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
138 set_default_d_op(sb, &v9fs_cached_dentry_operations);
139 } else {
140 set_default_d_op(sb, &v9fs_dentry_operations);
141 sb->s_d_flags |= DCACHE_DONTCACHE;
142 }
143
144 inode = v9fs_get_new_inode_from_fid(v9ses, fid, sb);
145 if (IS_ERR(ptr: inode)) {
146 retval = PTR_ERR(ptr: inode);
147 goto release_sb;
148 }
149
150 root = d_make_root(inode);
151 if (!root) {
152 retval = -ENOMEM;
153 goto release_sb;
154 }
155 sb->s_root = root;
156 retval = v9fs_get_acl(inode, fid);
157 if (retval)
158 goto release_sb;
159 v9fs_fid_add(dentry: root, fid: &fid);
160
161 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
162 return dget(dentry: sb->s_root);
163
164clunk_fid:
165 p9_fid_put(fid);
166 v9fs_session_close(v9ses);
167free_session:
168 kfree(objp: v9ses);
169 return ERR_PTR(error: retval);
170
171release_sb:
172 /*
173 * we will do the session_close and root dentry release
174 * in the below call. But we need to clunk fid, because we haven't
175 * attached the fid to dentry so it won't get clunked
176 * automatically.
177 */
178 p9_fid_put(fid);
179 deactivate_locked_super(sb);
180 return ERR_PTR(error: retval);
181}
182
183/**
184 * v9fs_kill_super - Kill Superblock
185 * @s: superblock
186 *
187 */
188
189static void v9fs_kill_super(struct super_block *s)
190{
191 struct v9fs_session_info *v9ses = s->s_fs_info;
192
193 p9_debug(P9_DEBUG_VFS, " %p\n", s);
194
195 kill_anon_super(sb: s);
196
197 v9fs_session_cancel(v9ses);
198 v9fs_session_close(v9ses);
199 kfree(objp: v9ses);
200 s->s_fs_info = NULL;
201 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n");
202}
203
204static void
205v9fs_umount_begin(struct super_block *sb)
206{
207 struct v9fs_session_info *v9ses;
208
209 v9ses = sb->s_fs_info;
210 v9fs_session_begin_cancel(v9ses);
211}
212
213static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
214{
215 struct v9fs_session_info *v9ses;
216 struct p9_fid *fid;
217 struct p9_rstatfs rs;
218 int res;
219
220 fid = v9fs_fid_lookup(dentry);
221 if (IS_ERR(ptr: fid)) {
222 res = PTR_ERR(ptr: fid);
223 goto done;
224 }
225
226 v9ses = v9fs_dentry2v9ses(dentry);
227 if (v9fs_proto_dotl(v9ses)) {
228 res = p9_client_statfs(fid, sb: &rs);
229 if (res == 0) {
230 buf->f_type = rs.type;
231 buf->f_bsize = rs.bsize;
232 buf->f_blocks = rs.blocks;
233 buf->f_bfree = rs.bfree;
234 buf->f_bavail = rs.bavail;
235 buf->f_files = rs.files;
236 buf->f_ffree = rs.ffree;
237 buf->f_fsid = u64_to_fsid(v: rs.fsid);
238 buf->f_namelen = rs.namelen;
239 }
240 if (res != -ENOSYS)
241 goto done;
242 }
243 res = simple_statfs(dentry, buf);
244done:
245 p9_fid_put(fid);
246 return res;
247}
248
249static int v9fs_drop_inode(struct inode *inode)
250{
251 struct v9fs_session_info *v9ses;
252
253 v9ses = v9fs_inode2v9ses(inode);
254 if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
255 return inode_generic_drop(inode);
256 /*
257 * in case of non cached mode always drop the
258 * inode because we want the inode attribute
259 * to always match that on the server.
260 */
261 return 1;
262}
263
264static int v9fs_write_inode(struct inode *inode,
265 struct writeback_control *wbc)
266{
267 /*
268 * send an fsync request to server irrespective of
269 * wbc->sync_mode.
270 */
271 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
272 return netfs_unpin_writeback(inode, wbc);
273}
274
275static int v9fs_write_inode_dotl(struct inode *inode,
276 struct writeback_control *wbc)
277{
278
279 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
280
281 return netfs_unpin_writeback(inode, wbc);
282}
283
284static const struct super_operations v9fs_super_ops = {
285 .alloc_inode = v9fs_alloc_inode,
286 .free_inode = v9fs_free_inode,
287 .statfs = simple_statfs,
288 .drop_inode = v9fs_drop_inode,
289 .evict_inode = v9fs_evict_inode,
290 .show_options = v9fs_show_options,
291 .umount_begin = v9fs_umount_begin,
292 .write_inode = v9fs_write_inode,
293};
294
295static const struct super_operations v9fs_super_ops_dotl = {
296 .alloc_inode = v9fs_alloc_inode,
297 .free_inode = v9fs_free_inode,
298 .statfs = v9fs_statfs,
299 .drop_inode = v9fs_drop_inode,
300 .evict_inode = v9fs_evict_inode,
301 .show_options = v9fs_show_options,
302 .umount_begin = v9fs_umount_begin,
303 .write_inode = v9fs_write_inode_dotl,
304};
305
306struct file_system_type v9fs_fs_type = {
307 .name = "9p",
308 .mount = v9fs_mount,
309 .kill_sb = v9fs_kill_super,
310 .owner = THIS_MODULE,
311 .fs_flags = FS_RENAME_DOES_D_MOVE,
312};
313MODULE_ALIAS_FS("9p");
314