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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 "internal.h"
8#include <linux/prefetch.h>
9#include <linux/sched/mm.h>
10#include <linux/dax.h>
11#include <trace/events/erofs.h>
12
13void erofs_unmap_metabuf(struct erofs_buf *buf)
14{
15 if (buf->kmap_type == EROFS_KMAP)
16 kunmap_local(buf->base);
17 buf->base = NULL;
18 buf->kmap_type = EROFS_NO_KMAP;
19}
20
21void erofs_put_metabuf(struct erofs_buf *buf)
22{
23 if (!buf->page)
24 return;
25 erofs_unmap_metabuf(buf);
26 put_page(buf->page);
27 buf->page = NULL;
28}
29
30void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
31 erofs_blk_t blkaddr, enum erofs_kmap_type type)
32{
33 struct address_space *const mapping = inode->i_mapping;
34 erofs_off_t offset = blknr_to_addr(blkaddr);
35 pgoff_t index = offset >> PAGE_SHIFT;
36 struct page *page = buf->page;
37 struct folio *folio;
38 unsigned int nofs_flag;
39
40 if (!page || page->index != index) {
41 erofs_put_metabuf(buf);
42
43 nofs_flag = memalloc_nofs_save();
44 folio = read_cache_folio(mapping, index, NULL, NULL);
45 memalloc_nofs_restore(nofs_flag);
46 if (IS_ERR(folio))
47 return folio;
48
49 /* should already be PageUptodate, no need to lock page */
50 page = folio_file_page(folio, index);
51 buf->page = page;
52 }
53 if (buf->kmap_type == EROFS_NO_KMAP) {
54 if (type == EROFS_KMAP)
55 buf->base = kmap_local_page(page);
56 buf->kmap_type = type;
57 } else if (buf->kmap_type != type) {
58 DBG_BUGON(1);
59 return ERR_PTR(-EFAULT);
60 }
61 if (type == EROFS_NO_KMAP)
62 return NULL;
63 return buf->base + (offset & ~PAGE_MASK);
64}
65
66void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
67 erofs_blk_t blkaddr, enum erofs_kmap_type type)
68{
69 if (erofs_is_fscache_mode(sb))
70 return erofs_bread(buf, EROFS_SB(sb)->s_fscache->inode,
71 blkaddr, type);
72
73 return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type);
74}
75
76static int erofs_map_blocks_flatmode(struct inode *inode,
77 struct erofs_map_blocks *map,
78 int flags)
79{
80 erofs_blk_t nblocks, lastblk;
81 u64 offset = map->m_la;
82 struct erofs_inode *vi = EROFS_I(inode);
83 bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
84
85 nblocks = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
86 lastblk = nblocks - tailendpacking;
87
88 /* there is no hole in flatmode */
89 map->m_flags = EROFS_MAP_MAPPED;
90 if (offset < blknr_to_addr(lastblk)) {
91 map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
92 map->m_plen = blknr_to_addr(lastblk) - offset;
93 } else if (tailendpacking) {
94 /* 2 - inode inline B: inode, [xattrs], inline last blk... */
95 struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
96
97 map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize +
98 vi->xattr_isize + erofs_blkoff(map->m_la);
99 map->m_plen = inode->i_size - offset;
100
101 /* inline data should be located in the same meta block */
102 if (erofs_blkoff(map->m_pa) + map->m_plen > EROFS_BLKSIZ) {
103 erofs_err(inode->i_sb,
104 "inline data cross block boundary @ nid %llu",
105 vi->nid);
106 DBG_BUGON(1);
107 return -EFSCORRUPTED;
108 }
109 map->m_flags |= EROFS_MAP_META;
110 } else {
111 erofs_err(inode->i_sb,
112 "internal error @ nid: %llu (size %llu), m_la 0x%llx",
113 vi->nid, inode->i_size, map->m_la);
114 DBG_BUGON(1);
115 return -EIO;
116 }
117 return 0;
118}
119
120int erofs_map_blocks(struct inode *inode,
121 struct erofs_map_blocks *map, int flags)
122{
123 struct super_block *sb = inode->i_sb;
124 struct erofs_inode *vi = EROFS_I(inode);
125 struct erofs_inode_chunk_index *idx;
126 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
127 u64 chunknr;
128 unsigned int unit;
129 erofs_off_t pos;
130 void *kaddr;
131 int err = 0;
132
133 trace_erofs_map_blocks_enter(inode, map, flags);
134 map->m_deviceid = 0;
135 if (map->m_la >= inode->i_size) {
136 /* leave out-of-bound access unmapped */
137 map->m_flags = 0;
138 map->m_plen = 0;
139 goto out;
140 }
141
142 if (vi->datalayout != EROFS_INODE_CHUNK_BASED) {
143 err = erofs_map_blocks_flatmode(inode, map, flags);
144 goto out;
145 }
146
147 if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
148 unit = sizeof(*idx); /* chunk index */
149 else
150 unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */
151
152 chunknr = map->m_la >> vi->chunkbits;
153 pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
154 vi->xattr_isize, unit) + unit * chunknr;
155
156 kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), EROFS_KMAP);
157 if (IS_ERR(kaddr)) {
158 err = PTR_ERR(kaddr);
159 goto out;
160 }
161 map->m_la = chunknr << vi->chunkbits;
162 map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits,
163 roundup(inode->i_size - map->m_la, EROFS_BLKSIZ));
164
165 /* handle block map */
166 if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
167 __le32 *blkaddr = kaddr + erofs_blkoff(pos);
168
169 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
170 map->m_flags = 0;
171 } else {
172 map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr));
173 map->m_flags = EROFS_MAP_MAPPED;
174 }
175 goto out_unlock;
176 }
177 /* parse chunk indexes */
178 idx = kaddr + erofs_blkoff(pos);
179 switch (le32_to_cpu(idx->blkaddr)) {
180 case EROFS_NULL_ADDR:
181 map->m_flags = 0;
182 break;
183 default:
184 map->m_deviceid = le16_to_cpu(idx->device_id) &
185 EROFS_SB(sb)->device_id_mask;
186 map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr));
187 map->m_flags = EROFS_MAP_MAPPED;
188 break;
189 }
190out_unlock:
191 erofs_put_metabuf(&buf);
192out:
193 if (!err)
194 map->m_llen = map->m_plen;
195 trace_erofs_map_blocks_exit(inode, map, flags, 0);
196 return err;
197}
198
199int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
200{
201 struct erofs_dev_context *devs = EROFS_SB(sb)->devs;
202 struct erofs_device_info *dif;
203 int id;
204
205 /* primary device by default */
206 map->m_bdev = sb->s_bdev;
207 map->m_daxdev = EROFS_SB(sb)->dax_dev;
208 map->m_dax_part_off = EROFS_SB(sb)->dax_part_off;
209 map->m_fscache = EROFS_SB(sb)->s_fscache;
210
211 if (map->m_deviceid) {
212 down_read(&devs->rwsem);
213 dif = idr_find(&devs->tree, map->m_deviceid - 1);
214 if (!dif) {
215 up_read(&devs->rwsem);
216 return -ENODEV;
217 }
218 map->m_bdev = dif->bdev;
219 map->m_daxdev = dif->dax_dev;
220 map->m_dax_part_off = dif->dax_part_off;
221 map->m_fscache = dif->fscache;
222 up_read(&devs->rwsem);
223 } else if (devs->extra_devices) {
224 down_read(&devs->rwsem);
225 idr_for_each_entry(&devs->tree, dif, id) {
226 erofs_off_t startoff, length;
227
228 if (!dif->mapped_blkaddr)
229 continue;
230 startoff = blknr_to_addr(dif->mapped_blkaddr);
231 length = blknr_to_addr(dif->blocks);
232
233 if (map->m_pa >= startoff &&
234 map->m_pa < startoff + length) {
235 map->m_pa -= startoff;
236 map->m_bdev = dif->bdev;
237 map->m_daxdev = dif->dax_dev;
238 map->m_dax_part_off = dif->dax_part_off;
239 map->m_fscache = dif->fscache;
240 break;
241 }
242 }
243 up_read(&devs->rwsem);
244 }
245 return 0;
246}
247
248static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
249 unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
250{
251 int ret;
252 struct erofs_map_blocks map;
253 struct erofs_map_dev mdev;
254
255 map.m_la = offset;
256 map.m_llen = length;
257
258 ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
259 if (ret < 0)
260 return ret;
261
262 mdev = (struct erofs_map_dev) {
263 .m_deviceid = map.m_deviceid,
264 .m_pa = map.m_pa,
265 };
266 ret = erofs_map_dev(inode->i_sb, &mdev);
267 if (ret)
268 return ret;
269
270 iomap->offset = map.m_la;
271 if (flags & IOMAP_DAX)
272 iomap->dax_dev = mdev.m_daxdev;
273 else
274 iomap->bdev = mdev.m_bdev;
275 iomap->length = map.m_llen;
276 iomap->flags = 0;
277 iomap->private = NULL;
278
279 if (!(map.m_flags & EROFS_MAP_MAPPED)) {
280 iomap->type = IOMAP_HOLE;
281 iomap->addr = IOMAP_NULL_ADDR;
282 if (!iomap->length)
283 iomap->length = length;
284 return 0;
285 }
286
287 if (map.m_flags & EROFS_MAP_META) {
288 void *ptr;
289 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
290
291 iomap->type = IOMAP_INLINE;
292 ptr = erofs_read_metabuf(&buf, inode->i_sb,
293 erofs_blknr(mdev.m_pa), EROFS_KMAP);
294 if (IS_ERR(ptr))
295 return PTR_ERR(ptr);
296 iomap->inline_data = ptr + erofs_blkoff(mdev.m_pa);
297 iomap->private = buf.base;
298 } else {
299 iomap->type = IOMAP_MAPPED;
300 iomap->addr = mdev.m_pa;
301 if (flags & IOMAP_DAX)
302 iomap->addr += mdev.m_dax_part_off;
303 }
304 return 0;
305}
306
307static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
308 ssize_t written, unsigned int flags, struct iomap *iomap)
309{
310 void *ptr = iomap->private;
311
312 if (ptr) {
313 struct erofs_buf buf = {
314 .page = kmap_to_page(ptr),
315 .base = ptr,
316 .kmap_type = EROFS_KMAP,
317 };
318
319 DBG_BUGON(iomap->type != IOMAP_INLINE);
320 erofs_put_metabuf(&buf);
321 } else {
322 DBG_BUGON(iomap->type == IOMAP_INLINE);
323 }
324 return written;
325}
326
327static const struct iomap_ops erofs_iomap_ops = {
328 .iomap_begin = erofs_iomap_begin,
329 .iomap_end = erofs_iomap_end,
330};
331
332int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
333 u64 start, u64 len)
334{
335 if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
336#ifdef CONFIG_EROFS_FS_ZIP
337 return iomap_fiemap(inode, fieinfo, start, len,
338 &z_erofs_iomap_report_ops);
339#else
340 return -EOPNOTSUPP;
341#endif
342 }
343 return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops);
344}
345
346/*
347 * since we dont have write or truncate flows, so no inode
348 * locking needs to be held at the moment.
349 */
350static int erofs_read_folio(struct file *file, struct folio *folio)
351{
352 return iomap_read_folio(folio, &erofs_iomap_ops);
353}
354
355static void erofs_readahead(struct readahead_control *rac)
356{
357 return iomap_readahead(rac, &erofs_iomap_ops);
358}
359
360static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
361{
362 return iomap_bmap(mapping, block, &erofs_iomap_ops);
363}
364
365static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
366{
367 struct inode *inode = file_inode(iocb->ki_filp);
368
369 /* no need taking (shared) inode lock since it's a ro filesystem */
370 if (!iov_iter_count(to))
371 return 0;
372
373#ifdef CONFIG_FS_DAX
374 if (IS_DAX(inode))
375 return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
376#endif
377 if (iocb->ki_flags & IOCB_DIRECT) {
378 struct block_device *bdev = inode->i_sb->s_bdev;
379 unsigned int blksize_mask;
380
381 if (bdev)
382 blksize_mask = bdev_logical_block_size(bdev) - 1;
383 else
384 blksize_mask = (1 << inode->i_blkbits) - 1;
385
386 if ((iocb->ki_pos | iov_iter_count(to) |
387 iov_iter_alignment(to)) & blksize_mask)
388 return -EINVAL;
389
390 return iomap_dio_rw(iocb, to, &erofs_iomap_ops,
391 NULL, 0, NULL, 0);
392 }
393 return filemap_read(iocb, to, 0);
394}
395
396/* for uncompressed (aligned) files and raw access for other files */
397const struct address_space_operations erofs_raw_access_aops = {
398 .read_folio = erofs_read_folio,
399 .readahead = erofs_readahead,
400 .bmap = erofs_bmap,
401 .direct_IO = noop_direct_IO,
402 .release_folio = iomap_release_folio,
403 .invalidate_folio = iomap_invalidate_folio,
404};
405
406#ifdef CONFIG_FS_DAX
407static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf,
408 enum page_entry_size pe_size)
409{
410 return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops);
411}
412
413static vm_fault_t erofs_dax_fault(struct vm_fault *vmf)
414{
415 return erofs_dax_huge_fault(vmf, PE_SIZE_PTE);
416}
417
418static const struct vm_operations_struct erofs_dax_vm_ops = {
419 .fault = erofs_dax_fault,
420 .huge_fault = erofs_dax_huge_fault,
421};
422
423static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma)
424{
425 if (!IS_DAX(file_inode(file)))
426 return generic_file_readonly_mmap(file, vma);
427
428 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
429 return -EINVAL;
430
431 vma->vm_ops = &erofs_dax_vm_ops;
432 vma->vm_flags |= VM_HUGEPAGE;
433 return 0;
434}
435#else
436#define erofs_file_mmap generic_file_readonly_mmap
437#endif
438
439const struct file_operations erofs_file_fops = {
440 .llseek = generic_file_llseek,
441 .read_iter = erofs_file_read_iter,
442 .mmap = erofs_file_mmap,
443 .splice_read = generic_file_splice_read,
444};