1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2011, Lawrence Livermore National Security, LLC.
23 */
24
25
26 #include <sys/zfs_znode.h>
27 #include <sys/zfs_vfsops.h>
28 #include <sys/zfs_vnops.h>
29 #include <sys/zfs_ctldir.h>
30 #include <sys/zpl.h>
31
32
33 static struct inode *
zpl_inode_alloc(struct super_block * sb)34 zpl_inode_alloc(struct super_block *sb)
35 {
36 struct inode *ip;
37
38 VERIFY3S(zfs_inode_alloc(sb, &ip), ==, 0);
39 inode_set_iversion(ip, 1);
40
41 return (ip);
42 }
43
44 static void
zpl_inode_destroy(struct inode * ip)45 zpl_inode_destroy(struct inode *ip)
46 {
47 ASSERT(atomic_read(&ip->i_count) == 0);
48 zfs_inode_destroy(ip);
49 }
50
51 /*
52 * Called from __mark_inode_dirty() to reflect that something in the
53 * inode has changed. We use it to ensure the znode system attributes
54 * are always strictly update to date with respect to the inode.
55 */
56 #ifdef HAVE_DIRTY_INODE_WITH_FLAGS
57 static void
zpl_dirty_inode(struct inode * ip,int flags)58 zpl_dirty_inode(struct inode *ip, int flags)
59 {
60 fstrans_cookie_t cookie;
61
62 cookie = spl_fstrans_mark();
63 zfs_dirty_inode(ip, flags);
64 spl_fstrans_unmark(cookie);
65 }
66 #else
67 static void
zpl_dirty_inode(struct inode * ip)68 zpl_dirty_inode(struct inode *ip)
69 {
70 fstrans_cookie_t cookie;
71
72 cookie = spl_fstrans_mark();
73 zfs_dirty_inode(ip, 0);
74 spl_fstrans_unmark(cookie);
75 }
76 #endif /* HAVE_DIRTY_INODE_WITH_FLAGS */
77
78 /*
79 * When ->drop_inode() is called its return value indicates if the
80 * inode should be evicted from the inode cache. If the inode is
81 * unhashed and has no links the default policy is to evict it
82 * immediately.
83 *
84 * The ->evict_inode() callback must minimally truncate the inode pages,
85 * and call clear_inode(). For 2.6.35 and later kernels this will
86 * simply update the inode state, with the sync occurring before the
87 * truncate in evict(). For earlier kernels clear_inode() maps to
88 * end_writeback() which is responsible for completing all outstanding
89 * write back. In either case, once this is done it is safe to cleanup
90 * any remaining inode specific data via zfs_inactive().
91 * remaining filesystem specific data.
92 */
93 static void
zpl_evict_inode(struct inode * ip)94 zpl_evict_inode(struct inode *ip)
95 {
96 fstrans_cookie_t cookie;
97
98 cookie = spl_fstrans_mark();
99 truncate_setsize(ip, 0);
100 clear_inode(ip);
101 zfs_inactive(ip);
102 spl_fstrans_unmark(cookie);
103 }
104
105 static void
zpl_put_super(struct super_block * sb)106 zpl_put_super(struct super_block *sb)
107 {
108 fstrans_cookie_t cookie;
109 int error;
110
111 cookie = spl_fstrans_mark();
112 error = -zfs_umount(sb);
113 spl_fstrans_unmark(cookie);
114 ASSERT3S(error, <=, 0);
115 }
116
117 static int
zpl_sync_fs(struct super_block * sb,int wait)118 zpl_sync_fs(struct super_block *sb, int wait)
119 {
120 fstrans_cookie_t cookie;
121 cred_t *cr = CRED();
122 int error;
123
124 crhold(cr);
125 cookie = spl_fstrans_mark();
126 error = -zfs_sync(sb, wait, cr);
127 spl_fstrans_unmark(cookie);
128 crfree(cr);
129 ASSERT3S(error, <=, 0);
130
131 return (error);
132 }
133
134 static int
zpl_statfs(struct dentry * dentry,struct kstatfs * statp)135 zpl_statfs(struct dentry *dentry, struct kstatfs *statp)
136 {
137 fstrans_cookie_t cookie;
138 int error;
139
140 cookie = spl_fstrans_mark();
141 error = -zfs_statvfs(dentry->d_inode, statp);
142 spl_fstrans_unmark(cookie);
143 ASSERT3S(error, <=, 0);
144
145 /*
146 * If required by a 32-bit system call, dynamically scale the
147 * block size up to 16MiB and decrease the block counts. This
148 * allows for a maximum size of 64EiB to be reported. The file
149 * counts must be artificially capped at 2^32-1.
150 */
151 if (unlikely(zpl_is_32bit_api())) {
152 while (statp->f_blocks > UINT32_MAX &&
153 statp->f_bsize < SPA_MAXBLOCKSIZE) {
154 statp->f_frsize <<= 1;
155 statp->f_bsize <<= 1;
156
157 statp->f_blocks >>= 1;
158 statp->f_bfree >>= 1;
159 statp->f_bavail >>= 1;
160 }
161
162 uint64_t usedobjs = statp->f_files - statp->f_ffree;
163 statp->f_ffree = MIN(statp->f_ffree, UINT32_MAX - usedobjs);
164 statp->f_files = statp->f_ffree + usedobjs;
165 }
166
167 return (error);
168 }
169
170 static int
zpl_remount_fs(struct super_block * sb,int * flags,char * data)171 zpl_remount_fs(struct super_block *sb, int *flags, char *data)
172 {
173 zfs_mnt_t zm = { .mnt_osname = NULL, .mnt_data = data };
174 fstrans_cookie_t cookie;
175 int error;
176
177 cookie = spl_fstrans_mark();
178 error = -zfs_remount(sb, flags, &zm);
179 spl_fstrans_unmark(cookie);
180 ASSERT3S(error, <=, 0);
181
182 return (error);
183 }
184
185 static int
__zpl_show_devname(struct seq_file * seq,zfsvfs_t * zfsvfs)186 __zpl_show_devname(struct seq_file *seq, zfsvfs_t *zfsvfs)
187 {
188 ZPL_ENTER(zfsvfs);
189
190 char *fsname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
191 dmu_objset_name(zfsvfs->z_os, fsname);
192
193 for (int i = 0; fsname[i] != 0; i++) {
194 /*
195 * Spaces in the dataset name must be converted to their
196 * octal escape sequence for getmntent(3) to correctly
197 * parse then fsname portion of /proc/self/mounts.
198 */
199 if (fsname[i] == ' ') {
200 seq_puts(seq, "\\040");
201 } else {
202 seq_putc(seq, fsname[i]);
203 }
204 }
205
206 kmem_free(fsname, ZFS_MAX_DATASET_NAME_LEN);
207
208 ZPL_EXIT(zfsvfs);
209
210 return (0);
211 }
212
213 static int
zpl_show_devname(struct seq_file * seq,struct dentry * root)214 zpl_show_devname(struct seq_file *seq, struct dentry *root)
215 {
216 return (__zpl_show_devname(seq, root->d_sb->s_fs_info));
217 }
218
219 static int
__zpl_show_options(struct seq_file * seq,zfsvfs_t * zfsvfs)220 __zpl_show_options(struct seq_file *seq, zfsvfs_t *zfsvfs)
221 {
222 seq_printf(seq, ",%s",
223 zfsvfs->z_flags & ZSB_XATTR ? "xattr" : "noxattr");
224
225 #ifdef CONFIG_FS_POSIX_ACL
226 switch (zfsvfs->z_acl_type) {
227 case ZFS_ACLTYPE_POSIX:
228 seq_puts(seq, ",posixacl");
229 break;
230 default:
231 seq_puts(seq, ",noacl");
232 break;
233 }
234 #endif /* CONFIG_FS_POSIX_ACL */
235
236 return (0);
237 }
238
239 static int
zpl_show_options(struct seq_file * seq,struct dentry * root)240 zpl_show_options(struct seq_file *seq, struct dentry *root)
241 {
242 return (__zpl_show_options(seq, root->d_sb->s_fs_info));
243 }
244
245 static int
zpl_fill_super(struct super_block * sb,void * data,int silent)246 zpl_fill_super(struct super_block *sb, void *data, int silent)
247 {
248 zfs_mnt_t *zm = (zfs_mnt_t *)data;
249 fstrans_cookie_t cookie;
250 int error;
251
252 cookie = spl_fstrans_mark();
253 error = -zfs_domount(sb, zm, silent);
254 spl_fstrans_unmark(cookie);
255 ASSERT3S(error, <=, 0);
256
257 return (error);
258 }
259
260 static int
zpl_test_super(struct super_block * s,void * data)261 zpl_test_super(struct super_block *s, void *data)
262 {
263 zfsvfs_t *zfsvfs = s->s_fs_info;
264 objset_t *os = data;
265
266 if (zfsvfs == NULL)
267 return (0);
268
269 return (os == zfsvfs->z_os);
270 }
271
272 static struct super_block *
zpl_mount_impl(struct file_system_type * fs_type,int flags,zfs_mnt_t * zm)273 zpl_mount_impl(struct file_system_type *fs_type, int flags, zfs_mnt_t *zm)
274 {
275 struct super_block *s;
276 objset_t *os;
277 int err;
278
279 err = dmu_objset_hold(zm->mnt_osname, FTAG, &os);
280 if (err)
281 return (ERR_PTR(-err));
282
283 /*
284 * The dsl pool lock must be released prior to calling sget().
285 * It is possible sget() may block on the lock in grab_super()
286 * while deactivate_super() holds that same lock and waits for
287 * a txg sync. If the dsl_pool lock is held over sget()
288 * this can prevent the pool sync and cause a deadlock.
289 */
290 dsl_dataset_long_hold(dmu_objset_ds(os), FTAG);
291 dsl_pool_rele(dmu_objset_pool(os), FTAG);
292
293 s = sget(fs_type, zpl_test_super, set_anon_super, flags, os);
294
295 dsl_dataset_long_rele(dmu_objset_ds(os), FTAG);
296 dsl_dataset_rele(dmu_objset_ds(os), FTAG);
297
298 if (IS_ERR(s))
299 return (ERR_CAST(s));
300
301 if (s->s_root == NULL) {
302 err = zpl_fill_super(s, zm, flags & SB_SILENT ? 1 : 0);
303 if (err) {
304 deactivate_locked_super(s);
305 return (ERR_PTR(err));
306 }
307 s->s_flags |= SB_ACTIVE;
308 } else if ((flags ^ s->s_flags) & SB_RDONLY) {
309 deactivate_locked_super(s);
310 return (ERR_PTR(-EBUSY));
311 }
312
313 return (s);
314 }
315
316 static struct dentry *
zpl_mount(struct file_system_type * fs_type,int flags,const char * osname,void * data)317 zpl_mount(struct file_system_type *fs_type, int flags,
318 const char *osname, void *data)
319 {
320 zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };
321
322 struct super_block *sb = zpl_mount_impl(fs_type, flags, &zm);
323 if (IS_ERR(sb))
324 return (ERR_CAST(sb));
325
326 return (dget(sb->s_root));
327 }
328
329 static void
zpl_kill_sb(struct super_block * sb)330 zpl_kill_sb(struct super_block *sb)
331 {
332 zfs_preumount(sb);
333 kill_anon_super(sb);
334 }
335
336 void
zpl_prune_sb(int64_t nr_to_scan,void * arg)337 zpl_prune_sb(int64_t nr_to_scan, void *arg)
338 {
339 struct super_block *sb = (struct super_block *)arg;
340 int objects = 0;
341
342 (void) -zfs_prune(sb, nr_to_scan, &objects);
343 }
344
345 const struct super_operations zpl_super_operations = {
346 .alloc_inode = zpl_inode_alloc,
347 .destroy_inode = zpl_inode_destroy,
348 .dirty_inode = zpl_dirty_inode,
349 .write_inode = NULL,
350 .evict_inode = zpl_evict_inode,
351 .put_super = zpl_put_super,
352 .sync_fs = zpl_sync_fs,
353 .statfs = zpl_statfs,
354 .remount_fs = zpl_remount_fs,
355 .show_devname = zpl_show_devname,
356 .show_options = zpl_show_options,
357 .show_stats = NULL,
358 };
359
360 struct file_system_type zpl_fs_type = {
361 .owner = THIS_MODULE,
362 .name = ZFS_DRIVER,
363 .mount = zpl_mount,
364 .kill_sb = zpl_kill_sb,
365 };
366