xref: /linux/fs/erofs/inode.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 
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 
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 
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  */
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 
281 static int erofs_iget5_eq(struct inode *inode, void *opaque)
282 {
283 	return EROFS_I(inode)->nid == *(erofs_nid_t *)opaque;
284 }
285 
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 
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 
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 	struct block_device *bdev = inode->i_sb->s_bdev;
322 	bool compressed =
323 		erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout);
324 
325 	if (compressed)
326 		stat->attributes |= STATX_ATTR_COMPRESSED;
327 	stat->attributes |= STATX_ATTR_IMMUTABLE;
328 	stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
329 				  STATX_ATTR_IMMUTABLE);
330 
331 	/*
332 	 * Return the DIO alignment restrictions if requested.
333 	 *
334 	 * In EROFS, STATX_DIOALIGN is only supported in bdev-based mode
335 	 * and uncompressed inodes, otherwise we report no DIO support.
336 	 */
337 	if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) {
338 		stat->result_mask |= STATX_DIOALIGN;
339 		if (bdev && !compressed) {
340 			stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
341 			stat->dio_offset_align = bdev_logical_block_size(bdev);
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