1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2017-2018 HUAWEI, Inc.
4 * https://www.huawei.com/
5 * Copyright (C) 2021, Alibaba Cloud
6 */
7 #include "xattr.h"
8 #include <trace/events/erofs.h>
9
erofs_fill_symlink(struct inode * inode,void * kaddr,unsigned int m_pofs)10 static int erofs_fill_symlink(struct inode *inode, void *kaddr,
11 unsigned int m_pofs)
12 {
13 struct erofs_inode *vi = EROFS_I(inode);
14 loff_t off;
15
16 m_pofs += vi->xattr_isize;
17 /* check if it cannot be handled with fast symlink scheme */
18 if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
19 check_add_overflow(m_pofs, inode->i_size, &off) ||
20 off > i_blocksize(inode))
21 return 0;
22
23 inode->i_link = kmemdup_nul(kaddr + m_pofs, inode->i_size, GFP_KERNEL);
24 return inode->i_link ? 0 : -ENOMEM;
25 }
26
erofs_read_inode(struct inode * inode)27 static int erofs_read_inode(struct inode *inode)
28 {
29 struct super_block *sb = inode->i_sb;
30 struct erofs_sb_info *sbi = EROFS_SB(sb);
31 struct erofs_inode *vi = EROFS_I(inode);
32 const erofs_off_t inode_loc = erofs_iloc(inode);
33 erofs_blk_t blkaddr, nblks = 0;
34 void *kaddr;
35 struct erofs_inode_compact *dic;
36 struct erofs_inode_extended *die, *copied = NULL;
37 union erofs_inode_i_u iu;
38 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
39 unsigned int ifmt, ofs;
40 int err = 0;
41
42 blkaddr = erofs_blknr(sb, inode_loc);
43 ofs = erofs_blkoff(sb, inode_loc);
44
45 kaddr = erofs_read_metabuf(&buf, sb, erofs_pos(sb, blkaddr), EROFS_KMAP);
46 if (IS_ERR(kaddr)) {
47 erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
48 vi->nid, PTR_ERR(kaddr));
49 return PTR_ERR(kaddr);
50 }
51
52 dic = kaddr + ofs;
53 ifmt = le16_to_cpu(dic->i_format);
54 if (ifmt & ~EROFS_I_ALL) {
55 erofs_err(sb, "unsupported i_format %u of nid %llu",
56 ifmt, vi->nid);
57 err = -EOPNOTSUPP;
58 goto err_out;
59 }
60
61 vi->datalayout = erofs_inode_datalayout(ifmt);
62 if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
63 erofs_err(sb, "unsupported datalayout %u of nid %llu",
64 vi->datalayout, vi->nid);
65 err = -EOPNOTSUPP;
66 goto err_out;
67 }
68
69 switch (erofs_inode_version(ifmt)) {
70 case EROFS_INODE_LAYOUT_EXTENDED:
71 vi->inode_isize = sizeof(struct erofs_inode_extended);
72 /* check if the extended inode acrosses block boundary */
73 if (ofs + vi->inode_isize <= sb->s_blocksize) {
74 ofs += vi->inode_isize;
75 die = (struct erofs_inode_extended *)dic;
76 } else {
77 const unsigned int gotten = sb->s_blocksize - ofs;
78
79 copied = kmalloc(vi->inode_isize, GFP_KERNEL);
80 if (!copied) {
81 err = -ENOMEM;
82 goto err_out;
83 }
84 memcpy(copied, dic, gotten);
85 kaddr = erofs_read_metabuf(&buf, sb, erofs_pos(sb, blkaddr + 1),
86 EROFS_KMAP);
87 if (IS_ERR(kaddr)) {
88 erofs_err(sb, "failed to get inode payload block (nid: %llu), err %ld",
89 vi->nid, PTR_ERR(kaddr));
90 kfree(copied);
91 return PTR_ERR(kaddr);
92 }
93 ofs = vi->inode_isize - gotten;
94 memcpy((u8 *)copied + gotten, kaddr, ofs);
95 die = copied;
96 }
97 vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
98
99 inode->i_mode = le16_to_cpu(die->i_mode);
100 iu = die->i_u;
101 i_uid_write(inode, le32_to_cpu(die->i_uid));
102 i_gid_write(inode, le32_to_cpu(die->i_gid));
103 set_nlink(inode, le32_to_cpu(die->i_nlink));
104 /* each extended inode has its own timestamp */
105 inode_set_ctime(inode, le64_to_cpu(die->i_mtime),
106 le32_to_cpu(die->i_mtime_nsec));
107
108 inode->i_size = le64_to_cpu(die->i_size);
109 kfree(copied);
110 break;
111 case EROFS_INODE_LAYOUT_COMPACT:
112 vi->inode_isize = sizeof(struct erofs_inode_compact);
113 ofs += vi->inode_isize;
114 vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
115
116 inode->i_mode = le16_to_cpu(dic->i_mode);
117 iu = dic->i_u;
118 i_uid_write(inode, le16_to_cpu(dic->i_uid));
119 i_gid_write(inode, le16_to_cpu(dic->i_gid));
120 set_nlink(inode, le16_to_cpu(dic->i_nlink));
121 /* use build time for compact inodes */
122 inode_set_ctime(inode, sbi->build_time, sbi->build_time_nsec);
123
124 inode->i_size = le32_to_cpu(dic->i_size);
125 break;
126 default:
127 erofs_err(sb, "unsupported on-disk inode version %u of nid %llu",
128 erofs_inode_version(ifmt), vi->nid);
129 err = -EOPNOTSUPP;
130 goto err_out;
131 }
132
133 if (unlikely(inode->i_size < 0)) {
134 erofs_err(sb, "negative i_size @ nid %llu", vi->nid);
135 err = -EFSCORRUPTED;
136 goto err_out;
137 }
138 switch (inode->i_mode & S_IFMT) {
139 case S_IFREG:
140 case S_IFDIR:
141 case S_IFLNK:
142 vi->raw_blkaddr = le32_to_cpu(iu.raw_blkaddr);
143 if(S_ISLNK(inode->i_mode)) {
144 err = erofs_fill_symlink(inode, kaddr, ofs);
145 if (err)
146 goto err_out;
147 }
148 break;
149 case S_IFCHR:
150 case S_IFBLK:
151 inode->i_rdev = new_decode_dev(le32_to_cpu(iu.rdev));
152 break;
153 case S_IFIFO:
154 case S_IFSOCK:
155 inode->i_rdev = 0;
156 break;
157 default:
158 erofs_err(sb, "bogus i_mode (%o) @ nid %llu", inode->i_mode,
159 vi->nid);
160 err = -EFSCORRUPTED;
161 goto err_out;
162 }
163
164 /* total blocks for compressed files */
165 if (erofs_inode_is_data_compressed(vi->datalayout)) {
166 nblks = le32_to_cpu(iu.compressed_blocks);
167 } else if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
168 /* fill chunked inode summary info */
169 vi->chunkformat = le16_to_cpu(iu.c.format);
170 if (vi->chunkformat & ~EROFS_CHUNK_FORMAT_ALL) {
171 erofs_err(sb, "unsupported chunk format %x of nid %llu",
172 vi->chunkformat, vi->nid);
173 err = -EOPNOTSUPP;
174 goto err_out;
175 }
176 vi->chunkbits = sb->s_blocksize_bits +
177 (vi->chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
178 }
179 inode_set_mtime_to_ts(inode,
180 inode_set_atime_to_ts(inode, inode_get_ctime(inode)));
181
182 inode->i_flags &= ~S_DAX;
183 if (test_opt(&sbi->opt, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
184 (vi->datalayout == EROFS_INODE_FLAT_PLAIN ||
185 vi->datalayout == EROFS_INODE_CHUNK_BASED))
186 inode->i_flags |= S_DAX;
187
188 if (!nblks)
189 /* measure inode.i_blocks as generic filesystems */
190 inode->i_blocks = round_up(inode->i_size, sb->s_blocksize) >> 9;
191 else
192 inode->i_blocks = nblks << (sb->s_blocksize_bits - 9);
193 err_out:
194 DBG_BUGON(err);
195 erofs_put_metabuf(&buf);
196 return err;
197 }
198
erofs_fill_inode(struct inode * inode)199 static int erofs_fill_inode(struct inode *inode)
200 {
201 struct erofs_inode *vi = EROFS_I(inode);
202 int err;
203
204 trace_erofs_fill_inode(inode);
205
206 /* read inode base data from disk */
207 err = erofs_read_inode(inode);
208 if (err)
209 return err;
210
211 /* setup the new inode */
212 switch (inode->i_mode & S_IFMT) {
213 case S_IFREG:
214 inode->i_op = &erofs_generic_iops;
215 if (erofs_inode_is_data_compressed(vi->datalayout))
216 inode->i_fop = &generic_ro_fops;
217 else
218 inode->i_fop = &erofs_file_fops;
219 break;
220 case S_IFDIR:
221 inode->i_op = &erofs_dir_iops;
222 inode->i_fop = &erofs_dir_fops;
223 inode_nohighmem(inode);
224 break;
225 case S_IFLNK:
226 if (inode->i_link)
227 inode->i_op = &erofs_fast_symlink_iops;
228 else
229 inode->i_op = &erofs_symlink_iops;
230 inode_nohighmem(inode);
231 break;
232 case S_IFCHR:
233 case S_IFBLK:
234 case S_IFIFO:
235 case S_IFSOCK:
236 inode->i_op = &erofs_generic_iops;
237 init_special_inode(inode, inode->i_mode, inode->i_rdev);
238 return 0;
239 default:
240 return -EFSCORRUPTED;
241 }
242
243 mapping_set_large_folios(inode->i_mapping);
244 if (erofs_inode_is_data_compressed(vi->datalayout)) {
245 #ifdef CONFIG_EROFS_FS_ZIP
246 DO_ONCE_LITE_IF(inode->i_blkbits != PAGE_SHIFT,
247 erofs_info, inode->i_sb,
248 "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
249 inode->i_mapping->a_ops = &z_erofs_aops;
250 #else
251 err = -EOPNOTSUPP;
252 #endif
253 } else {
254 inode->i_mapping->a_ops = &erofs_aops;
255 #ifdef CONFIG_EROFS_FS_ONDEMAND
256 if (erofs_is_fscache_mode(inode->i_sb))
257 inode->i_mapping->a_ops = &erofs_fscache_access_aops;
258 #endif
259 #ifdef CONFIG_EROFS_FS_BACKED_BY_FILE
260 if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb)))
261 inode->i_mapping->a_ops = &erofs_fileio_aops;
262 #endif
263 }
264
265 return err;
266 }
267
268 /*
269 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
270 * so that it will fit.
271 */
erofs_squash_ino(erofs_nid_t nid)272 static ino_t erofs_squash_ino(erofs_nid_t nid)
273 {
274 ino_t ino = (ino_t)nid;
275
276 if (sizeof(ino_t) < sizeof(erofs_nid_t))
277 ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
278 return ino;
279 }
280
erofs_iget5_eq(struct inode * inode,void * opaque)281 static int erofs_iget5_eq(struct inode *inode, void *opaque)
282 {
283 return EROFS_I(inode)->nid == *(erofs_nid_t *)opaque;
284 }
285
erofs_iget5_set(struct inode * inode,void * opaque)286 static int erofs_iget5_set(struct inode *inode, void *opaque)
287 {
288 const erofs_nid_t nid = *(erofs_nid_t *)opaque;
289
290 inode->i_ino = erofs_squash_ino(nid);
291 EROFS_I(inode)->nid = nid;
292 return 0;
293 }
294
erofs_iget(struct super_block * sb,erofs_nid_t nid)295 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
296 {
297 struct inode *inode;
298
299 inode = iget5_locked(sb, erofs_squash_ino(nid), erofs_iget5_eq,
300 erofs_iget5_set, &nid);
301 if (!inode)
302 return ERR_PTR(-ENOMEM);
303
304 if (inode->i_state & I_NEW) {
305 int err = erofs_fill_inode(inode);
306
307 if (err) {
308 iget_failed(inode);
309 return ERR_PTR(err);
310 }
311 unlock_new_inode(inode);
312 }
313 return inode;
314 }
315
erofs_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)316 int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
317 struct kstat *stat, u32 request_mask,
318 unsigned int query_flags)
319 {
320 struct inode *const inode = d_inode(path->dentry);
321 bool compressed =
322 erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout);
323
324 if (compressed)
325 stat->attributes |= STATX_ATTR_COMPRESSED;
326 stat->attributes |= STATX_ATTR_IMMUTABLE;
327 stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
328 STATX_ATTR_IMMUTABLE);
329
330 /*
331 * Return the DIO alignment restrictions if requested.
332 *
333 * In EROFS, STATX_DIOALIGN is not supported in ondemand mode and
334 * compressed files, so in these cases we report no DIO support.
335 */
336 if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) {
337 stat->result_mask |= STATX_DIOALIGN;
338 if (!erofs_is_fscache_mode(inode->i_sb) && !compressed) {
339 stat->dio_mem_align =
340 bdev_logical_block_size(inode->i_sb->s_bdev);
341 stat->dio_offset_align = stat->dio_mem_align;
342 }
343 }
344 generic_fillattr(idmap, request_mask, inode, stat);
345 return 0;
346 }
347
348 const struct inode_operations erofs_generic_iops = {
349 .getattr = erofs_getattr,
350 .listxattr = erofs_listxattr,
351 .get_inode_acl = erofs_get_acl,
352 .fiemap = erofs_fiemap,
353 };
354
355 const struct inode_operations erofs_symlink_iops = {
356 .get_link = page_get_link,
357 .getattr = erofs_getattr,
358 .listxattr = erofs_listxattr,
359 .get_inode_acl = erofs_get_acl,
360 };
361
362 const struct inode_operations erofs_fast_symlink_iops = {
363 .get_link = simple_get_link,
364 .getattr = erofs_getattr,
365 .listxattr = erofs_listxattr,
366 .get_inode_acl = erofs_get_acl,
367 };
368