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
11static 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 = erofs_iloc(inode);
18	erofs_blk_t blkaddr, nblks = 0;
19	void *kaddr;
20	struct erofs_inode_compact *dic;
21	struct erofs_inode_extended *die, *copied = NULL;
22	union erofs_inode_i_u iu;
23	unsigned int ifmt;
24	int err;
25
26	blkaddr = erofs_blknr(sb, inode_loc);
27	*ofs = erofs_blkoff(sb, inode_loc);
28
29	kaddr = erofs_read_metabuf(buf, sb, blkaddr, EROFS_KMAP);
30	if (IS_ERR(kaddr)) {
31		erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
32			  vi->nid, PTR_ERR(kaddr));
33		return kaddr;
34	}
35
36	dic = kaddr + *ofs;
37	ifmt = le16_to_cpu(dic->i_format);
38	if (ifmt & ~EROFS_I_ALL) {
39		erofs_err(sb, "unsupported i_format %u of nid %llu",
40			  ifmt, vi->nid);
41		err = -EOPNOTSUPP;
42		goto err_out;
43	}
44
45	vi->datalayout = erofs_inode_datalayout(ifmt);
46	if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
47		erofs_err(sb, "unsupported datalayout %u of nid %llu",
48			  vi->datalayout, vi->nid);
49		err = -EOPNOTSUPP;
50		goto err_out;
51	}
52
53	switch (erofs_inode_version(ifmt)) {
54	case EROFS_INODE_LAYOUT_EXTENDED:
55		vi->inode_isize = sizeof(struct erofs_inode_extended);
56		/* check if the extended inode acrosses block boundary */
57		if (*ofs + vi->inode_isize <= sb->s_blocksize) {
58			*ofs += vi->inode_isize;
59			die = (struct erofs_inode_extended *)dic;
60		} else {
61			const unsigned int gotten = sb->s_blocksize - *ofs;
62
63			copied = kmalloc(vi->inode_isize, GFP_KERNEL);
64			if (!copied) {
65				err = -ENOMEM;
66				goto err_out;
67			}
68			memcpy(copied, dic, gotten);
69			kaddr = erofs_read_metabuf(buf, sb, blkaddr + 1,
70						   EROFS_KMAP);
71			if (IS_ERR(kaddr)) {
72				erofs_err(sb, "failed to get inode payload block (nid: %llu), err %ld",
73					  vi->nid, PTR_ERR(kaddr));
74				kfree(copied);
75				return kaddr;
76			}
77			*ofs = vi->inode_isize - gotten;
78			memcpy((u8 *)copied + gotten, kaddr, *ofs);
79			die = copied;
80		}
81		vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
82
83		inode->i_mode = le16_to_cpu(die->i_mode);
84		iu = die->i_u;
85		i_uid_write(inode, le32_to_cpu(die->i_uid));
86		i_gid_write(inode, le32_to_cpu(die->i_gid));
87		set_nlink(inode, le32_to_cpu(die->i_nlink));
88		/* each extended inode has its own timestamp */
89		inode_set_ctime(inode, le64_to_cpu(die->i_mtime),
90				le32_to_cpu(die->i_mtime_nsec));
91
92		inode->i_size = le64_to_cpu(die->i_size);
93		kfree(copied);
94		copied = NULL;
95		break;
96	case EROFS_INODE_LAYOUT_COMPACT:
97		vi->inode_isize = sizeof(struct erofs_inode_compact);
98		*ofs += vi->inode_isize;
99		vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
100
101		inode->i_mode = le16_to_cpu(dic->i_mode);
102		iu = dic->i_u;
103		i_uid_write(inode, le16_to_cpu(dic->i_uid));
104		i_gid_write(inode, le16_to_cpu(dic->i_gid));
105		set_nlink(inode, le16_to_cpu(dic->i_nlink));
106		/* use build time for compact inodes */
107		inode_set_ctime(inode, sbi->build_time, sbi->build_time_nsec);
108
109		inode->i_size = le32_to_cpu(dic->i_size);
110		break;
111	default:
112		erofs_err(sb, "unsupported on-disk inode version %u of nid %llu",
113			  erofs_inode_version(ifmt), vi->nid);
114		err = -EOPNOTSUPP;
115		goto err_out;
116	}
117
118	switch (inode->i_mode & S_IFMT) {
119	case S_IFREG:
120	case S_IFDIR:
121	case S_IFLNK:
122		vi->raw_blkaddr = le32_to_cpu(iu.raw_blkaddr);
123		break;
124	case S_IFCHR:
125	case S_IFBLK:
126		inode->i_rdev = new_decode_dev(le32_to_cpu(iu.rdev));
127		break;
128	case S_IFIFO:
129	case S_IFSOCK:
130		inode->i_rdev = 0;
131		break;
132	default:
133		erofs_err(sb, "bogus i_mode (%o) @ nid %llu", inode->i_mode,
134			  vi->nid);
135		err = -EFSCORRUPTED;
136		goto err_out;
137	}
138
139	/* total blocks for compressed files */
140	if (erofs_inode_is_data_compressed(vi->datalayout)) {
141		nblks = le32_to_cpu(iu.compressed_blocks);
142	} else if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
143		/* fill chunked inode summary info */
144		vi->chunkformat = le16_to_cpu(iu.c.format);
145		if (vi->chunkformat & ~EROFS_CHUNK_FORMAT_ALL) {
146			erofs_err(sb, "unsupported chunk format %x of nid %llu",
147				  vi->chunkformat, vi->nid);
148			err = -EOPNOTSUPP;
149			goto err_out;
150		}
151		vi->chunkbits = sb->s_blocksize_bits +
152			(vi->chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
153	}
154	inode_set_mtime_to_ts(inode,
155			      inode_set_atime_to_ts(inode, inode_get_ctime(inode)));
156
157	inode->i_flags &= ~S_DAX;
158	if (test_opt(&sbi->opt, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
159	    (vi->datalayout == EROFS_INODE_FLAT_PLAIN ||
160	     vi->datalayout == EROFS_INODE_CHUNK_BASED))
161		inode->i_flags |= S_DAX;
162
163	if (!nblks)
164		/* measure inode.i_blocks as generic filesystems */
165		inode->i_blocks = round_up(inode->i_size, sb->s_blocksize) >> 9;
166	else
167		inode->i_blocks = nblks << (sb->s_blocksize_bits - 9);
168	return kaddr;
169
170err_out:
171	DBG_BUGON(1);
172	kfree(copied);
173	erofs_put_metabuf(buf);
174	return ERR_PTR(err);
175}
176
177static int erofs_fill_symlink(struct inode *inode, void *kaddr,
178			      unsigned int m_pofs)
179{
180	struct erofs_inode *vi = EROFS_I(inode);
181	unsigned int bsz = i_blocksize(inode);
182	char *lnk;
183
184	/* if it cannot be handled with fast symlink scheme */
185	if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
186	    inode->i_size >= bsz || inode->i_size < 0) {
187		inode->i_op = &erofs_symlink_iops;
188		return 0;
189	}
190
191	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
192	if (!lnk)
193		return -ENOMEM;
194
195	m_pofs += vi->xattr_isize;
196	/* inline symlink data shouldn't cross block boundary */
197	if (m_pofs + inode->i_size > bsz) {
198		kfree(lnk);
199		erofs_err(inode->i_sb,
200			  "inline data cross block boundary @ nid %llu",
201			  vi->nid);
202		DBG_BUGON(1);
203		return -EFSCORRUPTED;
204	}
205	memcpy(lnk, kaddr + m_pofs, inode->i_size);
206	lnk[inode->i_size] = '\0';
207
208	inode->i_link = lnk;
209	inode->i_op = &erofs_fast_symlink_iops;
210	return 0;
211}
212
213static int erofs_fill_inode(struct inode *inode)
214{
215	struct erofs_inode *vi = EROFS_I(inode);
216	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
217	void *kaddr;
218	unsigned int ofs;
219	int err = 0;
220
221	trace_erofs_fill_inode(inode);
222
223	/* read inode base data from disk */
224	kaddr = erofs_read_inode(&buf, inode, &ofs);
225	if (IS_ERR(kaddr))
226		return PTR_ERR(kaddr);
227
228	/* setup the new inode */
229	switch (inode->i_mode & S_IFMT) {
230	case S_IFREG:
231		inode->i_op = &erofs_generic_iops;
232		if (erofs_inode_is_data_compressed(vi->datalayout))
233			inode->i_fop = &generic_ro_fops;
234		else
235			inode->i_fop = &erofs_file_fops;
236		break;
237	case S_IFDIR:
238		inode->i_op = &erofs_dir_iops;
239		inode->i_fop = &erofs_dir_fops;
240		inode_nohighmem(inode);
241		break;
242	case S_IFLNK:
243		err = erofs_fill_symlink(inode, kaddr, ofs);
244		if (err)
245			goto out_unlock;
246		inode_nohighmem(inode);
247		break;
248	case S_IFCHR:
249	case S_IFBLK:
250	case S_IFIFO:
251	case S_IFSOCK:
252		inode->i_op = &erofs_generic_iops;
253		init_special_inode(inode, inode->i_mode, inode->i_rdev);
254		goto out_unlock;
255	default:
256		err = -EFSCORRUPTED;
257		goto out_unlock;
258	}
259
260	if (erofs_inode_is_data_compressed(vi->datalayout)) {
261#ifdef CONFIG_EROFS_FS_ZIP
262		DO_ONCE_LITE_IF(inode->i_blkbits != PAGE_SHIFT,
263			  erofs_info, inode->i_sb,
264			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
265		inode->i_mapping->a_ops = &z_erofs_aops;
266		err = 0;
267		goto out_unlock;
268#endif
269		err = -EOPNOTSUPP;
270		goto out_unlock;
271	}
272	inode->i_mapping->a_ops = &erofs_raw_access_aops;
273	mapping_set_large_folios(inode->i_mapping);
274#ifdef CONFIG_EROFS_FS_ONDEMAND
275	if (erofs_is_fscache_mode(inode->i_sb))
276		inode->i_mapping->a_ops = &erofs_fscache_access_aops;
277#endif
278
279out_unlock:
280	erofs_put_metabuf(&buf);
281	return err;
282}
283
284/*
285 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
286 * so that it will fit.
287 */
288static ino_t erofs_squash_ino(erofs_nid_t nid)
289{
290	ino_t ino = (ino_t)nid;
291
292	if (sizeof(ino_t) < sizeof(erofs_nid_t))
293		ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
294	return ino;
295}
296
297static int erofs_iget5_eq(struct inode *inode, void *opaque)
298{
299	return EROFS_I(inode)->nid == *(erofs_nid_t *)opaque;
300}
301
302static int erofs_iget5_set(struct inode *inode, void *opaque)
303{
304	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
305
306	inode->i_ino = erofs_squash_ino(nid);
307	EROFS_I(inode)->nid = nid;
308	return 0;
309}
310
311struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
312{
313	struct inode *inode;
314
315	inode = iget5_locked(sb, erofs_squash_ino(nid), erofs_iget5_eq,
316			     erofs_iget5_set, &nid);
317	if (!inode)
318		return ERR_PTR(-ENOMEM);
319
320	if (inode->i_state & I_NEW) {
321		int err = erofs_fill_inode(inode);
322
323		if (err) {
324			iget_failed(inode);
325			return ERR_PTR(err);
326		}
327		unlock_new_inode(inode);
328	}
329	return inode;
330}
331
332int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
333		  struct kstat *stat, u32 request_mask,
334		  unsigned int query_flags)
335{
336	struct inode *const inode = d_inode(path->dentry);
337
338	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
339		stat->attributes |= STATX_ATTR_COMPRESSED;
340
341	stat->attributes |= STATX_ATTR_IMMUTABLE;
342	stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
343				  STATX_ATTR_IMMUTABLE);
344
345	generic_fillattr(idmap, request_mask, inode, stat);
346	return 0;
347}
348
349const struct inode_operations erofs_generic_iops = {
350	.getattr = erofs_getattr,
351	.listxattr = erofs_listxattr,
352	.get_inode_acl = erofs_get_acl,
353	.fiemap = erofs_fiemap,
354};
355
356const struct inode_operations erofs_symlink_iops = {
357	.get_link = page_get_link,
358	.getattr = erofs_getattr,
359	.listxattr = erofs_listxattr,
360	.get_inode_acl = erofs_get_acl,
361};
362
363const struct inode_operations erofs_fast_symlink_iops = {
364	.get_link = simple_get_link,
365	.getattr = erofs_getattr,
366	.listxattr = erofs_listxattr,
367	.get_inode_acl = erofs_get_acl,
368};
369