xref: /openbmc/linux/fs/erofs/inode.c (revision da1d9caf)
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 
9 #include <trace/events/erofs.h>
10 
11 static void *erofs_read_inode(struct erofs_buf *buf,
12 			      struct inode *inode, unsigned int *ofs)
13 {
14 	struct super_block *sb = inode->i_sb;
15 	struct erofs_sb_info *sbi = EROFS_SB(sb);
16 	struct erofs_inode *vi = EROFS_I(inode);
17 	const erofs_off_t inode_loc = iloc(sbi, vi->nid);
18 
19 	erofs_blk_t blkaddr, nblks = 0;
20 	void *kaddr;
21 	struct erofs_inode_compact *dic;
22 	struct erofs_inode_extended *die, *copied = NULL;
23 	unsigned int ifmt;
24 	int err;
25 
26 	blkaddr = erofs_blknr(inode_loc);
27 	*ofs = erofs_blkoff(inode_loc);
28 
29 	erofs_dbg("%s, reading inode nid %llu at %u of blkaddr %u",
30 		  __func__, vi->nid, *ofs, blkaddr);
31 
32 	kaddr = erofs_read_metabuf(buf, sb, blkaddr, EROFS_KMAP);
33 	if (IS_ERR(kaddr)) {
34 		erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
35 			  vi->nid, PTR_ERR(kaddr));
36 		return kaddr;
37 	}
38 
39 	dic = kaddr + *ofs;
40 	ifmt = le16_to_cpu(dic->i_format);
41 
42 	if (ifmt & ~EROFS_I_ALL) {
43 		erofs_err(inode->i_sb, "unsupported i_format %u of nid %llu",
44 			  ifmt, vi->nid);
45 		err = -EOPNOTSUPP;
46 		goto err_out;
47 	}
48 
49 	vi->datalayout = erofs_inode_datalayout(ifmt);
50 	if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
51 		erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",
52 			  vi->datalayout, vi->nid);
53 		err = -EOPNOTSUPP;
54 		goto err_out;
55 	}
56 
57 	switch (erofs_inode_version(ifmt)) {
58 	case EROFS_INODE_LAYOUT_EXTENDED:
59 		vi->inode_isize = sizeof(struct erofs_inode_extended);
60 		/* check if the extended inode acrosses block boundary */
61 		if (*ofs + vi->inode_isize <= EROFS_BLKSIZ) {
62 			*ofs += vi->inode_isize;
63 			die = (struct erofs_inode_extended *)dic;
64 		} else {
65 			const unsigned int gotten = EROFS_BLKSIZ - *ofs;
66 
67 			copied = kmalloc(vi->inode_isize, GFP_NOFS);
68 			if (!copied) {
69 				err = -ENOMEM;
70 				goto err_out;
71 			}
72 			memcpy(copied, dic, gotten);
73 			kaddr = erofs_read_metabuf(buf, sb, blkaddr + 1,
74 						   EROFS_KMAP);
75 			if (IS_ERR(kaddr)) {
76 				erofs_err(sb, "failed to get inode payload block (nid: %llu), err %ld",
77 					  vi->nid, PTR_ERR(kaddr));
78 				kfree(copied);
79 				return kaddr;
80 			}
81 			*ofs = vi->inode_isize - gotten;
82 			memcpy((u8 *)copied + gotten, kaddr, *ofs);
83 			die = copied;
84 		}
85 		vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
86 
87 		inode->i_mode = le16_to_cpu(die->i_mode);
88 		switch (inode->i_mode & S_IFMT) {
89 		case S_IFREG:
90 		case S_IFDIR:
91 		case S_IFLNK:
92 			vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
93 			break;
94 		case S_IFCHR:
95 		case S_IFBLK:
96 			inode->i_rdev =
97 				new_decode_dev(le32_to_cpu(die->i_u.rdev));
98 			break;
99 		case S_IFIFO:
100 		case S_IFSOCK:
101 			inode->i_rdev = 0;
102 			break;
103 		default:
104 			goto bogusimode;
105 		}
106 		i_uid_write(inode, le32_to_cpu(die->i_uid));
107 		i_gid_write(inode, le32_to_cpu(die->i_gid));
108 		set_nlink(inode, le32_to_cpu(die->i_nlink));
109 
110 		/* extended inode has its own timestamp */
111 		inode->i_ctime.tv_sec = le64_to_cpu(die->i_mtime);
112 		inode->i_ctime.tv_nsec = le32_to_cpu(die->i_mtime_nsec);
113 
114 		inode->i_size = le64_to_cpu(die->i_size);
115 
116 		/* total blocks for compressed files */
117 		if (erofs_inode_is_data_compressed(vi->datalayout))
118 			nblks = le32_to_cpu(die->i_u.compressed_blocks);
119 		else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
120 			/* fill chunked inode summary info */
121 			vi->chunkformat = le16_to_cpu(die->i_u.c.format);
122 		kfree(copied);
123 		copied = NULL;
124 		break;
125 	case EROFS_INODE_LAYOUT_COMPACT:
126 		vi->inode_isize = sizeof(struct erofs_inode_compact);
127 		*ofs += vi->inode_isize;
128 		vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
129 
130 		inode->i_mode = le16_to_cpu(dic->i_mode);
131 		switch (inode->i_mode & S_IFMT) {
132 		case S_IFREG:
133 		case S_IFDIR:
134 		case S_IFLNK:
135 			vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
136 			break;
137 		case S_IFCHR:
138 		case S_IFBLK:
139 			inode->i_rdev =
140 				new_decode_dev(le32_to_cpu(dic->i_u.rdev));
141 			break;
142 		case S_IFIFO:
143 		case S_IFSOCK:
144 			inode->i_rdev = 0;
145 			break;
146 		default:
147 			goto bogusimode;
148 		}
149 		i_uid_write(inode, le16_to_cpu(dic->i_uid));
150 		i_gid_write(inode, le16_to_cpu(dic->i_gid));
151 		set_nlink(inode, le16_to_cpu(dic->i_nlink));
152 
153 		/* use build time for compact inodes */
154 		inode->i_ctime.tv_sec = sbi->build_time;
155 		inode->i_ctime.tv_nsec = sbi->build_time_nsec;
156 
157 		inode->i_size = le32_to_cpu(dic->i_size);
158 		if (erofs_inode_is_data_compressed(vi->datalayout))
159 			nblks = le32_to_cpu(dic->i_u.compressed_blocks);
160 		else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
161 			vi->chunkformat = le16_to_cpu(dic->i_u.c.format);
162 		break;
163 	default:
164 		erofs_err(inode->i_sb,
165 			  "unsupported on-disk inode version %u of nid %llu",
166 			  erofs_inode_version(ifmt), vi->nid);
167 		err = -EOPNOTSUPP;
168 		goto err_out;
169 	}
170 
171 	if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
172 		if (vi->chunkformat & ~EROFS_CHUNK_FORMAT_ALL) {
173 			erofs_err(inode->i_sb,
174 				  "unsupported chunk format %x of nid %llu",
175 				  vi->chunkformat, vi->nid);
176 			err = -EOPNOTSUPP;
177 			goto err_out;
178 		}
179 		vi->chunkbits = LOG_BLOCK_SIZE +
180 			(vi->chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
181 	}
182 	inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
183 	inode->i_atime.tv_sec = inode->i_ctime.tv_sec;
184 	inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
185 	inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
186 
187 	inode->i_flags &= ~S_DAX;
188 	if (test_opt(&sbi->opt, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
189 	    vi->datalayout == EROFS_INODE_FLAT_PLAIN)
190 		inode->i_flags |= S_DAX;
191 	if (!nblks)
192 		/* measure inode.i_blocks as generic filesystems */
193 		inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
194 	else
195 		inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
196 	return kaddr;
197 
198 bogusimode:
199 	erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
200 		  inode->i_mode, vi->nid);
201 	err = -EFSCORRUPTED;
202 err_out:
203 	DBG_BUGON(1);
204 	kfree(copied);
205 	erofs_put_metabuf(buf);
206 	return ERR_PTR(err);
207 }
208 
209 static int erofs_fill_symlink(struct inode *inode, void *kaddr,
210 			      unsigned int m_pofs)
211 {
212 	struct erofs_inode *vi = EROFS_I(inode);
213 	char *lnk;
214 
215 	/* if it cannot be handled with fast symlink scheme */
216 	if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
217 	    inode->i_size >= EROFS_BLKSIZ) {
218 		inode->i_op = &erofs_symlink_iops;
219 		return 0;
220 	}
221 
222 	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
223 	if (!lnk)
224 		return -ENOMEM;
225 
226 	m_pofs += vi->xattr_isize;
227 	/* inline symlink data shouldn't cross block boundary */
228 	if (m_pofs + inode->i_size > EROFS_BLKSIZ) {
229 		kfree(lnk);
230 		erofs_err(inode->i_sb,
231 			  "inline data cross block boundary @ nid %llu",
232 			  vi->nid);
233 		DBG_BUGON(1);
234 		return -EFSCORRUPTED;
235 	}
236 	memcpy(lnk, kaddr + m_pofs, inode->i_size);
237 	lnk[inode->i_size] = '\0';
238 
239 	inode->i_link = lnk;
240 	inode->i_op = &erofs_fast_symlink_iops;
241 	return 0;
242 }
243 
244 static int erofs_fill_inode(struct inode *inode, int isdir)
245 {
246 	struct erofs_inode *vi = EROFS_I(inode);
247 	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
248 	void *kaddr;
249 	unsigned int ofs;
250 	int err = 0;
251 
252 	trace_erofs_fill_inode(inode, isdir);
253 
254 	/* read inode base data from disk */
255 	kaddr = erofs_read_inode(&buf, inode, &ofs);
256 	if (IS_ERR(kaddr))
257 		return PTR_ERR(kaddr);
258 
259 	/* setup the new inode */
260 	switch (inode->i_mode & S_IFMT) {
261 	case S_IFREG:
262 		inode->i_op = &erofs_generic_iops;
263 		if (erofs_inode_is_data_compressed(vi->datalayout))
264 			inode->i_fop = &generic_ro_fops;
265 		else
266 			inode->i_fop = &erofs_file_fops;
267 		break;
268 	case S_IFDIR:
269 		inode->i_op = &erofs_dir_iops;
270 		inode->i_fop = &erofs_dir_fops;
271 		break;
272 	case S_IFLNK:
273 		err = erofs_fill_symlink(inode, kaddr, ofs);
274 		if (err)
275 			goto out_unlock;
276 		inode_nohighmem(inode);
277 		break;
278 	case S_IFCHR:
279 	case S_IFBLK:
280 	case S_IFIFO:
281 	case S_IFSOCK:
282 		inode->i_op = &erofs_generic_iops;
283 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
284 		goto out_unlock;
285 	default:
286 		err = -EFSCORRUPTED;
287 		goto out_unlock;
288 	}
289 
290 	if (erofs_inode_is_data_compressed(vi->datalayout)) {
291 		if (!erofs_is_fscache_mode(inode->i_sb))
292 			err = z_erofs_fill_inode(inode);
293 		else
294 			err = -EOPNOTSUPP;
295 		goto out_unlock;
296 	}
297 	inode->i_mapping->a_ops = &erofs_raw_access_aops;
298 #ifdef CONFIG_EROFS_FS_ONDEMAND
299 	if (erofs_is_fscache_mode(inode->i_sb))
300 		inode->i_mapping->a_ops = &erofs_fscache_access_aops;
301 #endif
302 
303 out_unlock:
304 	erofs_put_metabuf(&buf);
305 	return err;
306 }
307 
308 /*
309  * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
310  * we should do more for 32-bit platform to find the right inode.
311  */
312 static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
313 {
314 	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
315 
316 	return EROFS_I(inode)->nid == nid;
317 }
318 
319 static int erofs_iget_set_actor(struct inode *inode, void *opaque)
320 {
321 	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
322 
323 	inode->i_ino = erofs_inode_hash(nid);
324 	return 0;
325 }
326 
327 static inline struct inode *erofs_iget_locked(struct super_block *sb,
328 					      erofs_nid_t nid)
329 {
330 	const unsigned long hashval = erofs_inode_hash(nid);
331 
332 	return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
333 		erofs_iget_set_actor, &nid);
334 }
335 
336 struct inode *erofs_iget(struct super_block *sb,
337 			 erofs_nid_t nid,
338 			 bool isdir)
339 {
340 	struct inode *inode = erofs_iget_locked(sb, nid);
341 
342 	if (!inode)
343 		return ERR_PTR(-ENOMEM);
344 
345 	if (inode->i_state & I_NEW) {
346 		int err;
347 		struct erofs_inode *vi = EROFS_I(inode);
348 
349 		vi->nid = nid;
350 
351 		err = erofs_fill_inode(inode, isdir);
352 		if (!err)
353 			unlock_new_inode(inode);
354 		else {
355 			iget_failed(inode);
356 			inode = ERR_PTR(err);
357 		}
358 	}
359 	return inode;
360 }
361 
362 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
363 		  struct kstat *stat, u32 request_mask,
364 		  unsigned int query_flags)
365 {
366 	struct inode *const inode = d_inode(path->dentry);
367 
368 	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
369 		stat->attributes |= STATX_ATTR_COMPRESSED;
370 
371 	stat->attributes |= STATX_ATTR_IMMUTABLE;
372 	stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
373 				  STATX_ATTR_IMMUTABLE);
374 
375 	generic_fillattr(mnt_userns, inode, stat);
376 	return 0;
377 }
378 
379 const struct inode_operations erofs_generic_iops = {
380 	.getattr = erofs_getattr,
381 	.listxattr = erofs_listxattr,
382 	.get_acl = erofs_get_acl,
383 	.fiemap = erofs_fiemap,
384 };
385 
386 const struct inode_operations erofs_symlink_iops = {
387 	.get_link = page_get_link,
388 	.getattr = erofs_getattr,
389 	.listxattr = erofs_listxattr,
390 	.get_acl = erofs_get_acl,
391 };
392 
393 const struct inode_operations erofs_fast_symlink_iops = {
394 	.get_link = simple_get_link,
395 	.getattr = erofs_getattr,
396 	.listxattr = erofs_listxattr,
397 	.get_acl = erofs_get_acl,
398 };
399