Merge tag 'for-linus-5.16b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / fs / erofs / data.c
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/dax.h>
10 #include <trace/events/erofs.h>
11
12 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr)
13 {
14         struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;
15         struct page *page;
16
17         page = read_cache_page_gfp(mapping, blkaddr,
18                                    mapping_gfp_constraint(mapping, ~__GFP_FS));
19         /* should already be PageUptodate */
20         if (!IS_ERR(page))
21                 lock_page(page);
22         return page;
23 }
24
25 static int erofs_map_blocks_flatmode(struct inode *inode,
26                                      struct erofs_map_blocks *map,
27                                      int flags)
28 {
29         int err = 0;
30         erofs_blk_t nblocks, lastblk;
31         u64 offset = map->m_la;
32         struct erofs_inode *vi = EROFS_I(inode);
33         bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
34
35         trace_erofs_map_blocks_flatmode_enter(inode, map, flags);
36
37         nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
38         lastblk = nblocks - tailendpacking;
39
40         /* there is no hole in flatmode */
41         map->m_flags = EROFS_MAP_MAPPED;
42
43         if (offset < blknr_to_addr(lastblk)) {
44                 map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
45                 map->m_plen = blknr_to_addr(lastblk) - offset;
46         } else if (tailendpacking) {
47                 /* 2 - inode inline B: inode, [xattrs], inline last blk... */
48                 struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
49
50                 map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize +
51                         vi->xattr_isize + erofs_blkoff(map->m_la);
52                 map->m_plen = inode->i_size - offset;
53
54                 /* inline data should be located in one meta block */
55                 if (erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE) {
56                         erofs_err(inode->i_sb,
57                                   "inline data cross block boundary @ nid %llu",
58                                   vi->nid);
59                         DBG_BUGON(1);
60                         err = -EFSCORRUPTED;
61                         goto err_out;
62                 }
63
64                 map->m_flags |= EROFS_MAP_META;
65         } else {
66                 erofs_err(inode->i_sb,
67                           "internal error @ nid: %llu (size %llu), m_la 0x%llx",
68                           vi->nid, inode->i_size, map->m_la);
69                 DBG_BUGON(1);
70                 err = -EIO;
71                 goto err_out;
72         }
73
74         map->m_llen = map->m_plen;
75 err_out:
76         trace_erofs_map_blocks_flatmode_exit(inode, map, flags, 0);
77         return err;
78 }
79
80 static int erofs_map_blocks(struct inode *inode,
81                             struct erofs_map_blocks *map, int flags)
82 {
83         struct super_block *sb = inode->i_sb;
84         struct erofs_inode *vi = EROFS_I(inode);
85         struct erofs_inode_chunk_index *idx;
86         struct page *page;
87         u64 chunknr;
88         unsigned int unit;
89         erofs_off_t pos;
90         int err = 0;
91
92         map->m_deviceid = 0;
93         if (map->m_la >= inode->i_size) {
94                 /* leave out-of-bound access unmapped */
95                 map->m_flags = 0;
96                 map->m_plen = 0;
97                 goto out;
98         }
99
100         if (vi->datalayout != EROFS_INODE_CHUNK_BASED)
101                 return erofs_map_blocks_flatmode(inode, map, flags);
102
103         if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
104                 unit = sizeof(*idx);                    /* chunk index */
105         else
106                 unit = EROFS_BLOCK_MAP_ENTRY_SIZE;      /* block map */
107
108         chunknr = map->m_la >> vi->chunkbits;
109         pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
110                     vi->xattr_isize, unit) + unit * chunknr;
111
112         page = erofs_get_meta_page(inode->i_sb, erofs_blknr(pos));
113         if (IS_ERR(page))
114                 return PTR_ERR(page);
115
116         map->m_la = chunknr << vi->chunkbits;
117         map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits,
118                             roundup(inode->i_size - map->m_la, EROFS_BLKSIZ));
119
120         /* handle block map */
121         if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
122                 __le32 *blkaddr = page_address(page) + erofs_blkoff(pos);
123
124                 if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
125                         map->m_flags = 0;
126                 } else {
127                         map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr));
128                         map->m_flags = EROFS_MAP_MAPPED;
129                 }
130                 goto out_unlock;
131         }
132         /* parse chunk indexes */
133         idx = page_address(page) + erofs_blkoff(pos);
134         switch (le32_to_cpu(idx->blkaddr)) {
135         case EROFS_NULL_ADDR:
136                 map->m_flags = 0;
137                 break;
138         default:
139                 map->m_deviceid = le16_to_cpu(idx->device_id) &
140                         EROFS_SB(sb)->device_id_mask;
141                 map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr));
142                 map->m_flags = EROFS_MAP_MAPPED;
143                 break;
144         }
145 out_unlock:
146         unlock_page(page);
147         put_page(page);
148 out:
149         map->m_llen = map->m_plen;
150         return err;
151 }
152
153 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
154 {
155         struct erofs_dev_context *devs = EROFS_SB(sb)->devs;
156         struct erofs_device_info *dif;
157         int id;
158
159         /* primary device by default */
160         map->m_bdev = sb->s_bdev;
161         map->m_daxdev = EROFS_SB(sb)->dax_dev;
162
163         if (map->m_deviceid) {
164                 down_read(&devs->rwsem);
165                 dif = idr_find(&devs->tree, map->m_deviceid - 1);
166                 if (!dif) {
167                         up_read(&devs->rwsem);
168                         return -ENODEV;
169                 }
170                 map->m_bdev = dif->bdev;
171                 map->m_daxdev = dif->dax_dev;
172                 up_read(&devs->rwsem);
173         } else if (devs->extra_devices) {
174                 down_read(&devs->rwsem);
175                 idr_for_each_entry(&devs->tree, dif, id) {
176                         erofs_off_t startoff, length;
177
178                         if (!dif->mapped_blkaddr)
179                                 continue;
180                         startoff = blknr_to_addr(dif->mapped_blkaddr);
181                         length = blknr_to_addr(dif->blocks);
182
183                         if (map->m_pa >= startoff &&
184                             map->m_pa < startoff + length) {
185                                 map->m_pa -= startoff;
186                                 map->m_bdev = dif->bdev;
187                                 map->m_daxdev = dif->dax_dev;
188                                 break;
189                         }
190                 }
191                 up_read(&devs->rwsem);
192         }
193         return 0;
194 }
195
196 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
197                 unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
198 {
199         int ret;
200         struct erofs_map_blocks map;
201         struct erofs_map_dev mdev;
202
203         map.m_la = offset;
204         map.m_llen = length;
205
206         ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
207         if (ret < 0)
208                 return ret;
209
210         mdev = (struct erofs_map_dev) {
211                 .m_deviceid = map.m_deviceid,
212                 .m_pa = map.m_pa,
213         };
214         ret = erofs_map_dev(inode->i_sb, &mdev);
215         if (ret)
216                 return ret;
217
218         iomap->bdev = mdev.m_bdev;
219         iomap->dax_dev = mdev.m_daxdev;
220         iomap->offset = map.m_la;
221         iomap->length = map.m_llen;
222         iomap->flags = 0;
223         iomap->private = NULL;
224
225         if (!(map.m_flags & EROFS_MAP_MAPPED)) {
226                 iomap->type = IOMAP_HOLE;
227                 iomap->addr = IOMAP_NULL_ADDR;
228                 if (!iomap->length)
229                         iomap->length = length;
230                 return 0;
231         }
232
233         if (map.m_flags & EROFS_MAP_META) {
234                 struct page *ipage;
235
236                 iomap->type = IOMAP_INLINE;
237                 ipage = erofs_get_meta_page(inode->i_sb,
238                                             erofs_blknr(mdev.m_pa));
239                 if (IS_ERR(ipage))
240                         return PTR_ERR(ipage);
241                 iomap->inline_data = page_address(ipage) +
242                                         erofs_blkoff(mdev.m_pa);
243                 iomap->private = ipage;
244         } else {
245                 iomap->type = IOMAP_MAPPED;
246                 iomap->addr = mdev.m_pa;
247         }
248         return 0;
249 }
250
251 static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
252                 ssize_t written, unsigned int flags, struct iomap *iomap)
253 {
254         struct page *ipage = iomap->private;
255
256         if (ipage) {
257                 DBG_BUGON(iomap->type != IOMAP_INLINE);
258                 unlock_page(ipage);
259                 put_page(ipage);
260         } else {
261                 DBG_BUGON(iomap->type == IOMAP_INLINE);
262         }
263         return written;
264 }
265
266 static const struct iomap_ops erofs_iomap_ops = {
267         .iomap_begin = erofs_iomap_begin,
268         .iomap_end = erofs_iomap_end,
269 };
270
271 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
272                  u64 start, u64 len)
273 {
274         if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
275 #ifdef CONFIG_EROFS_FS_ZIP
276                 return iomap_fiemap(inode, fieinfo, start, len,
277                                     &z_erofs_iomap_report_ops);
278 #else
279                 return -EOPNOTSUPP;
280 #endif
281         }
282         return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops);
283 }
284
285 /*
286  * since we dont have write or truncate flows, so no inode
287  * locking needs to be held at the moment.
288  */
289 static int erofs_readpage(struct file *file, struct page *page)
290 {
291         return iomap_readpage(page, &erofs_iomap_ops);
292 }
293
294 static void erofs_readahead(struct readahead_control *rac)
295 {
296         return iomap_readahead(rac, &erofs_iomap_ops);
297 }
298
299 static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
300 {
301         return iomap_bmap(mapping, block, &erofs_iomap_ops);
302 }
303
304 static int erofs_prepare_dio(struct kiocb *iocb, struct iov_iter *to)
305 {
306         struct inode *inode = file_inode(iocb->ki_filp);
307         loff_t align = iocb->ki_pos | iov_iter_count(to) |
308                 iov_iter_alignment(to);
309         struct block_device *bdev = inode->i_sb->s_bdev;
310         unsigned int blksize_mask;
311
312         if (bdev)
313                 blksize_mask = (1 << ilog2(bdev_logical_block_size(bdev))) - 1;
314         else
315                 blksize_mask = (1 << inode->i_blkbits) - 1;
316
317         if (align & blksize_mask)
318                 return -EINVAL;
319         return 0;
320 }
321
322 static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
323 {
324         /* no need taking (shared) inode lock since it's a ro filesystem */
325         if (!iov_iter_count(to))
326                 return 0;
327
328 #ifdef CONFIG_FS_DAX
329         if (IS_DAX(iocb->ki_filp->f_mapping->host))
330                 return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
331 #endif
332         if (iocb->ki_flags & IOCB_DIRECT) {
333                 int err = erofs_prepare_dio(iocb, to);
334
335                 if (!err)
336                         return iomap_dio_rw(iocb, to, &erofs_iomap_ops,
337                                             NULL, 0, 0);
338                 if (err < 0)
339                         return err;
340         }
341         return filemap_read(iocb, to, 0);
342 }
343
344 /* for uncompressed (aligned) files and raw access for other files */
345 const struct address_space_operations erofs_raw_access_aops = {
346         .readpage = erofs_readpage,
347         .readahead = erofs_readahead,
348         .bmap = erofs_bmap,
349         .direct_IO = noop_direct_IO,
350 };
351
352 #ifdef CONFIG_FS_DAX
353 static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf,
354                 enum page_entry_size pe_size)
355 {
356         return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops);
357 }
358
359 static vm_fault_t erofs_dax_fault(struct vm_fault *vmf)
360 {
361         return erofs_dax_huge_fault(vmf, PE_SIZE_PTE);
362 }
363
364 static const struct vm_operations_struct erofs_dax_vm_ops = {
365         .fault          = erofs_dax_fault,
366         .huge_fault     = erofs_dax_huge_fault,
367 };
368
369 static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma)
370 {
371         if (!IS_DAX(file_inode(file)))
372                 return generic_file_readonly_mmap(file, vma);
373
374         if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
375                 return -EINVAL;
376
377         vma->vm_ops = &erofs_dax_vm_ops;
378         vma->vm_flags |= VM_HUGEPAGE;
379         return 0;
380 }
381 #else
382 #define erofs_file_mmap generic_file_readonly_mmap
383 #endif
384
385 const struct file_operations erofs_file_fops = {
386         .llseek         = generic_file_llseek,
387         .read_iter      = erofs_file_read_iter,
388         .mmap           = erofs_file_mmap,
389         .splice_read    = generic_file_splice_read,
390 };