~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/btrfs/file-item.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * Copyright (C) 2007 Oracle.  All rights reserved.
  4  */
  5 
  6 #include <linux/bio.h>
  7 #include <linux/slab.h>
  8 #include <linux/pagemap.h>
  9 #include <linux/highmem.h>
 10 #include "ctree.h"
 11 #include "disk-io.h"
 12 #include "transaction.h"
 13 #include "volumes.h"
 14 #include "print-tree.h"
 15 #include "compression.h"
 16 
 17 #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
 18                                    sizeof(struct btrfs_item) * 2) / \
 19                                   size) - 1))
 20 
 21 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
 22                                        PAGE_SIZE))
 23 
 24 #define MAX_ORDERED_SUM_BYTES(fs_info) ((PAGE_SIZE - \
 25                                    sizeof(struct btrfs_ordered_sum)) / \
 26                                    sizeof(u32) * (fs_info)->sectorsize)
 27 
 28 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 29                              struct btrfs_root *root,
 30                              u64 objectid, u64 pos,
 31                              u64 disk_offset, u64 disk_num_bytes,
 32                              u64 num_bytes, u64 offset, u64 ram_bytes,
 33                              u8 compression, u8 encryption, u16 other_encoding)
 34 {
 35         int ret = 0;
 36         struct btrfs_file_extent_item *item;
 37         struct btrfs_key file_key;
 38         struct btrfs_path *path;
 39         struct extent_buffer *leaf;
 40 
 41         path = btrfs_alloc_path();
 42         if (!path)
 43                 return -ENOMEM;
 44         file_key.objectid = objectid;
 45         file_key.offset = pos;
 46         file_key.type = BTRFS_EXTENT_DATA_KEY;
 47 
 48         path->leave_spinning = 1;
 49         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 50                                       sizeof(*item));
 51         if (ret < 0)
 52                 goto out;
 53         BUG_ON(ret); /* Can't happen */
 54         leaf = path->nodes[0];
 55         item = btrfs_item_ptr(leaf, path->slots[0],
 56                               struct btrfs_file_extent_item);
 57         btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
 58         btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
 59         btrfs_set_file_extent_offset(leaf, item, offset);
 60         btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
 61         btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
 62         btrfs_set_file_extent_generation(leaf, item, trans->transid);
 63         btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
 64         btrfs_set_file_extent_compression(leaf, item, compression);
 65         btrfs_set_file_extent_encryption(leaf, item, encryption);
 66         btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
 67 
 68         btrfs_mark_buffer_dirty(leaf);
 69 out:
 70         btrfs_free_path(path);
 71         return ret;
 72 }
 73 
 74 static struct btrfs_csum_item *
 75 btrfs_lookup_csum(struct btrfs_trans_handle *trans,
 76                   struct btrfs_root *root,
 77                   struct btrfs_path *path,
 78                   u64 bytenr, int cow)
 79 {
 80         struct btrfs_fs_info *fs_info = root->fs_info;
 81         int ret;
 82         struct btrfs_key file_key;
 83         struct btrfs_key found_key;
 84         struct btrfs_csum_item *item;
 85         struct extent_buffer *leaf;
 86         u64 csum_offset = 0;
 87         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
 88         int csums_in_item;
 89 
 90         file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
 91         file_key.offset = bytenr;
 92         file_key.type = BTRFS_EXTENT_CSUM_KEY;
 93         ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
 94         if (ret < 0)
 95                 goto fail;
 96         leaf = path->nodes[0];
 97         if (ret > 0) {
 98                 ret = 1;
 99                 if (path->slots[0] == 0)
100                         goto fail;
101                 path->slots[0]--;
102                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
103                 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
104                         goto fail;
105 
106                 csum_offset = (bytenr - found_key.offset) >>
107                                 fs_info->sb->s_blocksize_bits;
108                 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
109                 csums_in_item /= csum_size;
110 
111                 if (csum_offset == csums_in_item) {
112                         ret = -EFBIG;
113                         goto fail;
114                 } else if (csum_offset > csums_in_item) {
115                         goto fail;
116                 }
117         }
118         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
119         item = (struct btrfs_csum_item *)((unsigned char *)item +
120                                           csum_offset * csum_size);
121         return item;
122 fail:
123         if (ret > 0)
124                 ret = -ENOENT;
125         return ERR_PTR(ret);
126 }
127 
128 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
129                              struct btrfs_root *root,
130                              struct btrfs_path *path, u64 objectid,
131                              u64 offset, int mod)
132 {
133         int ret;
134         struct btrfs_key file_key;
135         int ins_len = mod < 0 ? -1 : 0;
136         int cow = mod != 0;
137 
138         file_key.objectid = objectid;
139         file_key.offset = offset;
140         file_key.type = BTRFS_EXTENT_DATA_KEY;
141         ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
142         return ret;
143 }
144 
145 static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err)
146 {
147         kfree(bio->csum_allocated);
148 }
149 
150 static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
151                                    u64 logical_offset, u32 *dst, int dio)
152 {
153         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
154         struct bio_vec bvec;
155         struct bvec_iter iter;
156         struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
157         struct btrfs_csum_item *item = NULL;
158         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
159         struct btrfs_path *path;
160         u8 *csum;
161         u64 offset = 0;
162         u64 item_start_offset = 0;
163         u64 item_last_offset = 0;
164         u64 disk_bytenr;
165         u64 page_bytes_left;
166         u32 diff;
167         int nblocks;
168         int count = 0;
169         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
170 
171         path = btrfs_alloc_path();
172         if (!path)
173                 return BLK_STS_RESOURCE;
174 
175         nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
176         if (!dst) {
177                 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
178                         btrfs_bio->csum_allocated = kmalloc_array(nblocks,
179                                         csum_size, GFP_NOFS);
180                         if (!btrfs_bio->csum_allocated) {
181                                 btrfs_free_path(path);
182                                 return BLK_STS_RESOURCE;
183                         }
184                         btrfs_bio->csum = btrfs_bio->csum_allocated;
185                         btrfs_bio->end_io = btrfs_io_bio_endio_readpage;
186                 } else {
187                         btrfs_bio->csum = btrfs_bio->csum_inline;
188                 }
189                 csum = btrfs_bio->csum;
190         } else {
191                 csum = (u8 *)dst;
192         }
193 
194         if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
195                 path->reada = READA_FORWARD;
196 
197         /*
198          * the free space stuff is only read when it hasn't been
199          * updated in the current transaction.  So, we can safely
200          * read from the commit root and sidestep a nasty deadlock
201          * between reading the free space cache and updating the csum tree.
202          */
203         if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
204                 path->search_commit_root = 1;
205                 path->skip_locking = 1;
206         }
207 
208         disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
209         if (dio)
210                 offset = logical_offset;
211 
212         bio_for_each_segment(bvec, bio, iter) {
213                 page_bytes_left = bvec.bv_len;
214                 if (count)
215                         goto next;
216 
217                 if (!dio)
218                         offset = page_offset(bvec.bv_page) + bvec.bv_offset;
219                 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
220                                                (u32 *)csum, nblocks);
221                 if (count)
222                         goto found;
223 
224                 if (!item || disk_bytenr < item_start_offset ||
225                     disk_bytenr >= item_last_offset) {
226                         struct btrfs_key found_key;
227                         u32 item_size;
228 
229                         if (item)
230                                 btrfs_release_path(path);
231                         item = btrfs_lookup_csum(NULL, fs_info->csum_root,
232                                                  path, disk_bytenr, 0);
233                         if (IS_ERR(item)) {
234                                 count = 1;
235                                 memset(csum, 0, csum_size);
236                                 if (BTRFS_I(inode)->root->root_key.objectid ==
237                                     BTRFS_DATA_RELOC_TREE_OBJECTID) {
238                                         set_extent_bits(io_tree, offset,
239                                                 offset + fs_info->sectorsize - 1,
240                                                 EXTENT_NODATASUM);
241                                 } else {
242                                         btrfs_info_rl(fs_info,
243                                                    "no csum found for inode %llu start %llu",
244                                                btrfs_ino(BTRFS_I(inode)), offset);
245                                 }
246                                 item = NULL;
247                                 btrfs_release_path(path);
248                                 goto found;
249                         }
250                         btrfs_item_key_to_cpu(path->nodes[0], &found_key,
251                                               path->slots[0]);
252 
253                         item_start_offset = found_key.offset;
254                         item_size = btrfs_item_size_nr(path->nodes[0],
255                                                        path->slots[0]);
256                         item_last_offset = item_start_offset +
257                                 (item_size / csum_size) *
258                                 fs_info->sectorsize;
259                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
260                                               struct btrfs_csum_item);
261                 }
262                 /*
263                  * this byte range must be able to fit inside
264                  * a single leaf so it will also fit inside a u32
265                  */
266                 diff = disk_bytenr - item_start_offset;
267                 diff = diff / fs_info->sectorsize;
268                 diff = diff * csum_size;
269                 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
270                                             inode->i_sb->s_blocksize_bits);
271                 read_extent_buffer(path->nodes[0], csum,
272                                    ((unsigned long)item) + diff,
273                                    csum_size * count);
274 found:
275                 csum += count * csum_size;
276                 nblocks -= count;
277 next:
278                 while (count--) {
279                         disk_bytenr += fs_info->sectorsize;
280                         offset += fs_info->sectorsize;
281                         page_bytes_left -= fs_info->sectorsize;
282                         if (!page_bytes_left)
283                                 break; /* move to next bio */
284                 }
285         }
286 
287         WARN_ON_ONCE(count);
288         btrfs_free_path(path);
289         return 0;
290 }
291 
292 blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u32 *dst)
293 {
294         return __btrfs_lookup_bio_sums(inode, bio, 0, dst, 0);
295 }
296 
297 blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio, u64 offset)
298 {
299         return __btrfs_lookup_bio_sums(inode, bio, offset, NULL, 1);
300 }
301 
302 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
303                              struct list_head *list, int search_commit)
304 {
305         struct btrfs_fs_info *fs_info = root->fs_info;
306         struct btrfs_key key;
307         struct btrfs_path *path;
308         struct extent_buffer *leaf;
309         struct btrfs_ordered_sum *sums;
310         struct btrfs_csum_item *item;
311         LIST_HEAD(tmplist);
312         unsigned long offset;
313         int ret;
314         size_t size;
315         u64 csum_end;
316         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
317 
318         ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
319                IS_ALIGNED(end + 1, fs_info->sectorsize));
320 
321         path = btrfs_alloc_path();
322         if (!path)
323                 return -ENOMEM;
324 
325         if (search_commit) {
326                 path->skip_locking = 1;
327                 path->reada = READA_FORWARD;
328                 path->search_commit_root = 1;
329         }
330 
331         key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
332         key.offset = start;
333         key.type = BTRFS_EXTENT_CSUM_KEY;
334 
335         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
336         if (ret < 0)
337                 goto fail;
338         if (ret > 0 && path->slots[0] > 0) {
339                 leaf = path->nodes[0];
340                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
341                 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
342                     key.type == BTRFS_EXTENT_CSUM_KEY) {
343                         offset = (start - key.offset) >>
344                                  fs_info->sb->s_blocksize_bits;
345                         if (offset * csum_size <
346                             btrfs_item_size_nr(leaf, path->slots[0] - 1))
347                                 path->slots[0]--;
348                 }
349         }
350 
351         while (start <= end) {
352                 leaf = path->nodes[0];
353                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
354                         ret = btrfs_next_leaf(root, path);
355                         if (ret < 0)
356                                 goto fail;
357                         if (ret > 0)
358                                 break;
359                         leaf = path->nodes[0];
360                 }
361 
362                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
363                 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
364                     key.type != BTRFS_EXTENT_CSUM_KEY ||
365                     key.offset > end)
366                         break;
367 
368                 if (key.offset > start)
369                         start = key.offset;
370 
371                 size = btrfs_item_size_nr(leaf, path->slots[0]);
372                 csum_end = key.offset + (size / csum_size) * fs_info->sectorsize;
373                 if (csum_end <= start) {
374                         path->slots[0]++;
375                         continue;
376                 }
377 
378                 csum_end = min(csum_end, end + 1);
379                 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
380                                       struct btrfs_csum_item);
381                 while (start < csum_end) {
382                         size = min_t(size_t, csum_end - start,
383                                      MAX_ORDERED_SUM_BYTES(fs_info));
384                         sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
385                                        GFP_NOFS);
386                         if (!sums) {
387                                 ret = -ENOMEM;
388                                 goto fail;
389                         }
390 
391                         sums->bytenr = start;
392                         sums->len = (int)size;
393 
394                         offset = (start - key.offset) >>
395                                 fs_info->sb->s_blocksize_bits;
396                         offset *= csum_size;
397                         size >>= fs_info->sb->s_blocksize_bits;
398 
399                         read_extent_buffer(path->nodes[0],
400                                            sums->sums,
401                                            ((unsigned long)item) + offset,
402                                            csum_size * size);
403 
404                         start += fs_info->sectorsize * size;
405                         list_add_tail(&sums->list, &tmplist);
406                 }
407                 path->slots[0]++;
408         }
409         ret = 0;
410 fail:
411         while (ret < 0 && !list_empty(&tmplist)) {
412                 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
413                 list_del(&sums->list);
414                 kfree(sums);
415         }
416         list_splice_tail(&tmplist, list);
417 
418         btrfs_free_path(path);
419         return ret;
420 }
421 
422 blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
423                        u64 file_start, int contig)
424 {
425         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
426         struct btrfs_ordered_sum *sums;
427         struct btrfs_ordered_extent *ordered = NULL;
428         char *data;
429         struct bvec_iter iter;
430         struct bio_vec bvec;
431         int index;
432         int nr_sectors;
433         unsigned long total_bytes = 0;
434         unsigned long this_sum_bytes = 0;
435         int i;
436         u64 offset;
437 
438         sums = kzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
439                        GFP_NOFS);
440         if (!sums)
441                 return BLK_STS_RESOURCE;
442 
443         sums->len = bio->bi_iter.bi_size;
444         INIT_LIST_HEAD(&sums->list);
445 
446         if (contig)
447                 offset = file_start;
448         else
449                 offset = 0; /* shut up gcc */
450 
451         sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
452         index = 0;
453 
454         bio_for_each_segment(bvec, bio, iter) {
455                 if (!contig)
456                         offset = page_offset(bvec.bv_page) + bvec.bv_offset;
457 
458                 if (!ordered) {
459                         ordered = btrfs_lookup_ordered_extent(inode, offset);
460                         BUG_ON(!ordered); /* Logic error */
461                 }
462 
463                 data = kmap_atomic(bvec.bv_page);
464 
465                 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
466                                                  bvec.bv_len + fs_info->sectorsize
467                                                  - 1);
468 
469                 for (i = 0; i < nr_sectors; i++) {
470                         if (offset >= ordered->file_offset + ordered->len ||
471                                 offset < ordered->file_offset) {
472                                 unsigned long bytes_left;
473 
474                                 kunmap_atomic(data);
475                                 sums->len = this_sum_bytes;
476                                 this_sum_bytes = 0;
477                                 btrfs_add_ordered_sum(inode, ordered, sums);
478                                 btrfs_put_ordered_extent(ordered);
479 
480                                 bytes_left = bio->bi_iter.bi_size - total_bytes;
481 
482                                 sums = kzalloc(btrfs_ordered_sum_size(fs_info, bytes_left),
483                                                GFP_NOFS);
484                                 BUG_ON(!sums); /* -ENOMEM */
485                                 sums->len = bytes_left;
486                                 ordered = btrfs_lookup_ordered_extent(inode,
487                                                                 offset);
488                                 ASSERT(ordered); /* Logic error */
489                                 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
490                                         + total_bytes;
491                                 index = 0;
492 
493                                 data = kmap_atomic(bvec.bv_page);
494                         }
495 
496                         sums->sums[index] = ~(u32)0;
497                         sums->sums[index]
498                                 = btrfs_csum_data(data + bvec.bv_offset
499                                                 + (i * fs_info->sectorsize),
500                                                 sums->sums[index],
501                                                 fs_info->sectorsize);
502                         btrfs_csum_final(sums->sums[index],
503                                         (char *)(sums->sums + index));
504                         index++;
505                         offset += fs_info->sectorsize;
506                         this_sum_bytes += fs_info->sectorsize;
507                         total_bytes += fs_info->sectorsize;
508                 }
509 
510                 kunmap_atomic(data);
511         }
512         this_sum_bytes = 0;
513         btrfs_add_ordered_sum(inode, ordered, sums);
514         btrfs_put_ordered_extent(ordered);
515         return 0;
516 }
517 
518 /*
519  * helper function for csum removal, this expects the
520  * key to describe the csum pointed to by the path, and it expects
521  * the csum to overlap the range [bytenr, len]
522  *
523  * The csum should not be entirely contained in the range and the
524  * range should not be entirely contained in the csum.
525  *
526  * This calls btrfs_truncate_item with the correct args based on the
527  * overlap, and fixes up the key as required.
528  */
529 static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
530                                        struct btrfs_path *path,
531                                        struct btrfs_key *key,
532                                        u64 bytenr, u64 len)
533 {
534         struct extent_buffer *leaf;
535         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
536         u64 csum_end;
537         u64 end_byte = bytenr + len;
538         u32 blocksize_bits = fs_info->sb->s_blocksize_bits;
539 
540         leaf = path->nodes[0];
541         csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
542         csum_end <<= fs_info->sb->s_blocksize_bits;
543         csum_end += key->offset;
544 
545         if (key->offset < bytenr && csum_end <= end_byte) {
546                 /*
547                  *         [ bytenr - len ]
548                  *         [   ]
549                  *   [csum     ]
550                  *   A simple truncate off the end of the item
551                  */
552                 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
553                 new_size *= csum_size;
554                 btrfs_truncate_item(fs_info, path, new_size, 1);
555         } else if (key->offset >= bytenr && csum_end > end_byte &&
556                    end_byte > key->offset) {
557                 /*
558                  *         [ bytenr - len ]
559                  *                 [ ]
560                  *                 [csum     ]
561                  * we need to truncate from the beginning of the csum
562                  */
563                 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
564                 new_size *= csum_size;
565 
566                 btrfs_truncate_item(fs_info, path, new_size, 0);
567 
568                 key->offset = end_byte;
569                 btrfs_set_item_key_safe(fs_info, path, key);
570         } else {
571                 BUG();
572         }
573 }
574 
575 /*
576  * deletes the csum items from the csum tree for a given
577  * range of bytes.
578  */
579 int btrfs_del_csums(struct btrfs_trans_handle *trans,
580                     struct btrfs_fs_info *fs_info, u64 bytenr, u64 len)
581 {
582         struct btrfs_root *root = fs_info->csum_root;
583         struct btrfs_path *path;
584         struct btrfs_key key;
585         u64 end_byte = bytenr + len;
586         u64 csum_end;
587         struct extent_buffer *leaf;
588         int ret;
589         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
590         int blocksize_bits = fs_info->sb->s_blocksize_bits;
591 
592         path = btrfs_alloc_path();
593         if (!path)
594                 return -ENOMEM;
595 
596         while (1) {
597                 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
598                 key.offset = end_byte - 1;
599                 key.type = BTRFS_EXTENT_CSUM_KEY;
600 
601                 path->leave_spinning = 1;
602                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
603                 if (ret > 0) {
604                         if (path->slots[0] == 0)
605                                 break;
606                         path->slots[0]--;
607                 } else if (ret < 0) {
608                         break;
609                 }
610 
611                 leaf = path->nodes[0];
612                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
613 
614                 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
615                     key.type != BTRFS_EXTENT_CSUM_KEY) {
616                         break;
617                 }
618 
619                 if (key.offset >= end_byte)
620                         break;
621 
622                 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
623                 csum_end <<= blocksize_bits;
624                 csum_end += key.offset;
625 
626                 /* this csum ends before we start, we're done */
627                 if (csum_end <= bytenr)
628                         break;
629 
630                 /* delete the entire item, it is inside our range */
631                 if (key.offset >= bytenr && csum_end <= end_byte) {
632                         int del_nr = 1;
633 
634                         /*
635                          * Check how many csum items preceding this one in this
636                          * leaf correspond to our range and then delete them all
637                          * at once.
638                          */
639                         if (key.offset > bytenr && path->slots[0] > 0) {
640                                 int slot = path->slots[0] - 1;
641 
642                                 while (slot >= 0) {
643                                         struct btrfs_key pk;
644 
645                                         btrfs_item_key_to_cpu(leaf, &pk, slot);
646                                         if (pk.offset < bytenr ||
647                                             pk.type != BTRFS_EXTENT_CSUM_KEY ||
648                                             pk.objectid !=
649                                             BTRFS_EXTENT_CSUM_OBJECTID)
650                                                 break;
651                                         path->slots[0] = slot;
652                                         del_nr++;
653                                         key.offset = pk.offset;
654                                         slot--;
655                                 }
656                         }
657                         ret = btrfs_del_items(trans, root, path,
658                                               path->slots[0], del_nr);
659                         if (ret)
660                                 goto out;
661                         if (key.offset == bytenr)
662                                 break;
663                 } else if (key.offset < bytenr && csum_end > end_byte) {
664                         unsigned long offset;
665                         unsigned long shift_len;
666                         unsigned long item_offset;
667                         /*
668                          *        [ bytenr - len ]
669                          *     [csum                ]
670                          *
671                          * Our bytes are in the middle of the csum,
672                          * we need to split this item and insert a new one.
673                          *
674                          * But we can't drop the path because the
675                          * csum could change, get removed, extended etc.
676                          *
677                          * The trick here is the max size of a csum item leaves
678                          * enough room in the tree block for a single
679                          * item header.  So, we split the item in place,
680                          * adding a new header pointing to the existing
681                          * bytes.  Then we loop around again and we have
682                          * a nicely formed csum item that we can neatly
683                          * truncate.
684                          */
685                         offset = (bytenr - key.offset) >> blocksize_bits;
686                         offset *= csum_size;
687 
688                         shift_len = (len >> blocksize_bits) * csum_size;
689 
690                         item_offset = btrfs_item_ptr_offset(leaf,
691                                                             path->slots[0]);
692 
693                         memzero_extent_buffer(leaf, item_offset + offset,
694                                              shift_len);
695                         key.offset = bytenr;
696 
697                         /*
698                          * btrfs_split_item returns -EAGAIN when the
699                          * item changed size or key
700                          */
701                         ret = btrfs_split_item(trans, root, path, &key, offset);
702                         if (ret && ret != -EAGAIN) {
703                                 btrfs_abort_transaction(trans, ret);
704                                 goto out;
705                         }
706 
707                         key.offset = end_byte - 1;
708                 } else {
709                         truncate_one_csum(fs_info, path, &key, bytenr, len);
710                         if (key.offset < bytenr)
711                                 break;
712                 }
713                 btrfs_release_path(path);
714         }
715         ret = 0;
716 out:
717         btrfs_free_path(path);
718         return ret;
719 }
720 
721 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
722                            struct btrfs_root *root,
723                            struct btrfs_ordered_sum *sums)
724 {
725         struct btrfs_fs_info *fs_info = root->fs_info;
726         struct btrfs_key file_key;
727         struct btrfs_key found_key;
728         struct btrfs_path *path;
729         struct btrfs_csum_item *item;
730         struct btrfs_csum_item *item_end;
731         struct extent_buffer *leaf = NULL;
732         u64 next_offset;
733         u64 total_bytes = 0;
734         u64 csum_offset;
735         u64 bytenr;
736         u32 nritems;
737         u32 ins_size;
738         int index = 0;
739         int found_next;
740         int ret;
741         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
742 
743         path = btrfs_alloc_path();
744         if (!path)
745                 return -ENOMEM;
746 again:
747         next_offset = (u64)-1;
748         found_next = 0;
749         bytenr = sums->bytenr + total_bytes;
750         file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
751         file_key.offset = bytenr;
752         file_key.type = BTRFS_EXTENT_CSUM_KEY;
753 
754         item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
755         if (!IS_ERR(item)) {
756                 ret = 0;
757                 leaf = path->nodes[0];
758                 item_end = btrfs_item_ptr(leaf, path->slots[0],
759                                           struct btrfs_csum_item);
760                 item_end = (struct btrfs_csum_item *)((char *)item_end +
761                            btrfs_item_size_nr(leaf, path->slots[0]));
762                 goto found;
763         }
764         ret = PTR_ERR(item);
765         if (ret != -EFBIG && ret != -ENOENT)
766                 goto fail_unlock;
767 
768         if (ret == -EFBIG) {
769                 u32 item_size;
770                 /* we found one, but it isn't big enough yet */
771                 leaf = path->nodes[0];
772                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
773                 if ((item_size / csum_size) >=
774                     MAX_CSUM_ITEMS(fs_info, csum_size)) {
775                         /* already at max size, make a new one */
776                         goto insert;
777                 }
778         } else {
779                 int slot = path->slots[0] + 1;
780                 /* we didn't find a csum item, insert one */
781                 nritems = btrfs_header_nritems(path->nodes[0]);
782                 if (!nritems || (path->slots[0] >= nritems - 1)) {
783                         ret = btrfs_next_leaf(root, path);
784                         if (ret == 1)
785                                 found_next = 1;
786                         if (ret != 0)
787                                 goto insert;
788                         slot = path->slots[0];
789                 }
790                 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
791                 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
792                     found_key.type != BTRFS_EXTENT_CSUM_KEY) {
793                         found_next = 1;
794                         goto insert;
795                 }
796                 next_offset = found_key.offset;
797                 found_next = 1;
798                 goto insert;
799         }
800 
801         /*
802          * at this point, we know the tree has an item, but it isn't big
803          * enough yet to put our csum in.  Grow it
804          */
805         btrfs_release_path(path);
806         ret = btrfs_search_slot(trans, root, &file_key, path,
807                                 csum_size, 1);
808         if (ret < 0)
809                 goto fail_unlock;
810 
811         if (ret > 0) {
812                 if (path->slots[0] == 0)
813                         goto insert;
814                 path->slots[0]--;
815         }
816 
817         leaf = path->nodes[0];
818         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
819         csum_offset = (bytenr - found_key.offset) >>
820                         fs_info->sb->s_blocksize_bits;
821 
822         if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
823             found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
824             csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
825                 goto insert;
826         }
827 
828         if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
829             csum_size) {
830                 int extend_nr;
831                 u64 tmp;
832                 u32 diff;
833                 u32 free_space;
834 
835                 if (btrfs_leaf_free_space(fs_info, leaf) <
836                                  sizeof(struct btrfs_item) + csum_size * 2)
837                         goto insert;
838 
839                 free_space = btrfs_leaf_free_space(fs_info, leaf) -
840                                          sizeof(struct btrfs_item) - csum_size;
841                 tmp = sums->len - total_bytes;
842                 tmp >>= fs_info->sb->s_blocksize_bits;
843                 WARN_ON(tmp < 1);
844 
845                 extend_nr = max_t(int, 1, (int)tmp);
846                 diff = (csum_offset + extend_nr) * csum_size;
847                 diff = min(diff,
848                            MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
849 
850                 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
851                 diff = min(free_space, diff);
852                 diff /= csum_size;
853                 diff *= csum_size;
854 
855                 btrfs_extend_item(fs_info, path, diff);
856                 ret = 0;
857                 goto csum;
858         }
859 
860 insert:
861         btrfs_release_path(path);
862         csum_offset = 0;
863         if (found_next) {
864                 u64 tmp;
865 
866                 tmp = sums->len - total_bytes;
867                 tmp >>= fs_info->sb->s_blocksize_bits;
868                 tmp = min(tmp, (next_offset - file_key.offset) >>
869                                          fs_info->sb->s_blocksize_bits);
870 
871                 tmp = max_t(u64, 1, tmp);
872                 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
873                 ins_size = csum_size * tmp;
874         } else {
875                 ins_size = csum_size;
876         }
877         path->leave_spinning = 1;
878         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
879                                       ins_size);
880         path->leave_spinning = 0;
881         if (ret < 0)
882                 goto fail_unlock;
883         if (WARN_ON(ret != 0))
884                 goto fail_unlock;
885         leaf = path->nodes[0];
886 csum:
887         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
888         item_end = (struct btrfs_csum_item *)((unsigned char *)item +
889                                       btrfs_item_size_nr(leaf, path->slots[0]));
890         item = (struct btrfs_csum_item *)((unsigned char *)item +
891                                           csum_offset * csum_size);
892 found:
893         ins_size = (u32)(sums->len - total_bytes) >>
894                    fs_info->sb->s_blocksize_bits;
895         ins_size *= csum_size;
896         ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
897                               ins_size);
898         write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
899                             ins_size);
900 
901         ins_size /= csum_size;
902         total_bytes += ins_size * fs_info->sectorsize;
903         index += ins_size;
904 
905         btrfs_mark_buffer_dirty(path->nodes[0]);
906         if (total_bytes < sums->len) {
907                 btrfs_release_path(path);
908                 cond_resched();
909                 goto again;
910         }
911 out:
912         btrfs_free_path(path);
913         return ret;
914 
915 fail_unlock:
916         goto out;
917 }
918 
919 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
920                                      const struct btrfs_path *path,
921                                      struct btrfs_file_extent_item *fi,
922                                      const bool new_inline,
923                                      struct extent_map *em)
924 {
925         struct btrfs_fs_info *fs_info = inode->root->fs_info;
926         struct btrfs_root *root = inode->root;
927         struct extent_buffer *leaf = path->nodes[0];
928         const int slot = path->slots[0];
929         struct btrfs_key key;
930         u64 extent_start, extent_end;
931         u64 bytenr;
932         u8 type = btrfs_file_extent_type(leaf, fi);
933         int compress_type = btrfs_file_extent_compression(leaf, fi);
934 
935         em->bdev = fs_info->fs_devices->latest_bdev;
936         btrfs_item_key_to_cpu(leaf, &key, slot);
937         extent_start = key.offset;
938 
939         if (type == BTRFS_FILE_EXTENT_REG ||
940             type == BTRFS_FILE_EXTENT_PREALLOC) {
941                 extent_end = extent_start +
942                         btrfs_file_extent_num_bytes(leaf, fi);
943         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
944                 size_t size;
945                 size = btrfs_file_extent_ram_bytes(leaf, fi);
946                 extent_end = ALIGN(extent_start + size,
947                                    fs_info->sectorsize);
948         }
949 
950         em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
951         if (type == BTRFS_FILE_EXTENT_REG ||
952             type == BTRFS_FILE_EXTENT_PREALLOC) {
953                 em->start = extent_start;
954                 em->len = extent_end - extent_start;
955                 em->orig_start = extent_start -
956                         btrfs_file_extent_offset(leaf, fi);
957                 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
958                 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
959                 if (bytenr == 0) {
960                         em->block_start = EXTENT_MAP_HOLE;
961                         return;
962                 }
963                 if (compress_type != BTRFS_COMPRESS_NONE) {
964                         set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
965                         em->compress_type = compress_type;
966                         em->block_start = bytenr;
967                         em->block_len = em->orig_block_len;
968                 } else {
969                         bytenr += btrfs_file_extent_offset(leaf, fi);
970                         em->block_start = bytenr;
971                         em->block_len = em->len;
972                         if (type == BTRFS_FILE_EXTENT_PREALLOC)
973                                 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
974                 }
975         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
976                 em->block_start = EXTENT_MAP_INLINE;
977                 em->start = extent_start;
978                 em->len = extent_end - extent_start;
979                 /*
980                  * Initialize orig_start and block_len with the same values
981                  * as in inode.c:btrfs_get_extent().
982                  */
983                 em->orig_start = EXTENT_MAP_HOLE;
984                 em->block_len = (u64)-1;
985                 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
986                         set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
987                         em->compress_type = compress_type;
988                 }
989         } else {
990                 btrfs_err(fs_info,
991                           "unknown file extent item type %d, inode %llu, offset %llu, "
992                           "root %llu", type, btrfs_ino(inode), extent_start,
993                           root->root_key.objectid);
994         }
995 }
996 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp