Lines Matching +full:page +full:- +full:offset
1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Squashfs - a compressed read only filesystem for Linux
14 * compressed fragment block (tail-end packed block). The compressed size
23 * retaining a simple and space-efficient block list on disk. The cache
44 * Locate cache slot in range [offset, index] for specified inode. If
47 static struct meta_index *locate_meta_index(struct inode *inode, int offset, in locate_meta_index() argument
51 struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; in locate_meta_index()
54 mutex_lock(&msblk->meta_index_mutex); in locate_meta_index()
56 TRACE("locate_meta_index: index %d, offset %d\n", index, offset); in locate_meta_index()
58 if (msblk->meta_index == NULL) in locate_meta_index()
62 if (msblk->meta_index[i].inode_number == inode->i_ino && in locate_meta_index()
63 msblk->meta_index[i].offset >= offset && in locate_meta_index()
64 msblk->meta_index[i].offset <= index && in locate_meta_index()
65 msblk->meta_index[i].locked == 0) { in locate_meta_index()
66 TRACE("locate_meta_index: entry %d, offset %d\n", i, in locate_meta_index()
67 msblk->meta_index[i].offset); in locate_meta_index()
68 meta = &msblk->meta_index[i]; in locate_meta_index()
69 offset = meta->offset; in locate_meta_index()
74 meta->locked = 1; in locate_meta_index()
77 mutex_unlock(&msblk->meta_index_mutex); in locate_meta_index()
84 * Find and initialise an empty cache slot for index offset.
86 static struct meta_index *empty_meta_index(struct inode *inode, int offset, in empty_meta_index() argument
89 struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; in empty_meta_index()
93 mutex_lock(&msblk->meta_index_mutex); in empty_meta_index()
95 TRACE("empty_meta_index: offset %d, skip %d\n", offset, skip); in empty_meta_index()
97 if (msblk->meta_index == NULL) { in empty_meta_index()
104 msblk->meta_index = kcalloc(SQUASHFS_META_SLOTS, in empty_meta_index()
105 sizeof(*(msblk->meta_index)), GFP_KERNEL); in empty_meta_index()
106 if (msblk->meta_index == NULL) { in empty_meta_index()
111 msblk->meta_index[i].inode_number = 0; in empty_meta_index()
112 msblk->meta_index[i].locked = 0; in empty_meta_index()
114 msblk->next_meta_index = 0; in empty_meta_index()
118 msblk->meta_index[msblk->next_meta_index].locked; i--) in empty_meta_index()
119 msblk->next_meta_index = (msblk->next_meta_index + 1) % in empty_meta_index()
128 msblk->next_meta_index, in empty_meta_index()
129 &msblk->meta_index[msblk->next_meta_index]); in empty_meta_index()
131 meta = &msblk->meta_index[msblk->next_meta_index]; in empty_meta_index()
132 msblk->next_meta_index = (msblk->next_meta_index + 1) % in empty_meta_index()
135 meta->inode_number = inode->i_ino; in empty_meta_index()
136 meta->offset = offset; in empty_meta_index()
137 meta->skip = skip; in empty_meta_index()
138 meta->entries = 0; in empty_meta_index()
139 meta->locked = 1; in empty_meta_index()
142 mutex_unlock(&msblk->meta_index_mutex); in empty_meta_index()
149 struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; in release_meta_index()
150 mutex_lock(&msblk->meta_index_mutex); in release_meta_index()
151 meta->locked = 0; in release_meta_index()
152 mutex_unlock(&msblk->meta_index_mutex); in release_meta_index()
158 * metadata block <start_block, offset>.
161 u64 *start_block, int *offset) in read_indexes() argument
169 return -ENOMEM; in read_indexes()
176 offset, blocks << 2); in read_indexes()
179 *start_block, *offset); in read_indexes()
191 n -= blocks; in read_indexes()
205 * can cache one index -> datablock/blocklist-block mapping. We wish
218 return min((u64) SQUASHFS_CACHED_BLKS - 1, skip + 1); in calculate_skip()
224 * on-disk locations of the datablock and block list metadata block
230 struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; in fill_meta_index()
231 int skip = calculate_skip(i_size_read(inode) >> msblk->block_log); in fill_meta_index()
232 int offset = 0; in fill_meta_index() local
235 u64 cur_index_block = squashfs_i(inode)->block_list_start; in fill_meta_index()
236 int cur_offset = squashfs_i(inode)->offset; in fill_meta_index()
237 u64 cur_data_block = squashfs_i(inode)->start; in fill_meta_index()
245 while (offset < index) { in fill_meta_index()
246 meta = locate_meta_index(inode, offset + 1, index); in fill_meta_index()
249 meta = empty_meta_index(inode, offset + 1, skip); in fill_meta_index()
253 offset = index < meta->offset + meta->entries ? index : in fill_meta_index()
254 meta->offset + meta->entries - 1; in fill_meta_index()
255 meta_entry = &meta->meta_entry[offset - meta->offset]; in fill_meta_index()
256 cur_index_block = meta_entry->index_block + in fill_meta_index()
257 msblk->inode_table; in fill_meta_index()
258 cur_offset = meta_entry->offset; in fill_meta_index()
259 cur_data_block = meta_entry->data_block; in fill_meta_index()
260 TRACE("get_meta_index: offset %d, meta->offset %d, " in fill_meta_index()
261 "meta->entries %d\n", offset, meta->offset, in fill_meta_index()
262 meta->entries); in fill_meta_index()
263 TRACE("get_meta_index: index_block 0x%llx, offset 0x%x" in fill_meta_index()
273 for (i = meta->offset + meta->entries; i <= index && in fill_meta_index()
274 i < meta->offset + SQUASHFS_META_ENTRIES; i++) { in fill_meta_index()
276 long long res = read_indexes(inode->i_sb, blocks, in fill_meta_index()
280 if (meta->entries == 0) in fill_meta_index()
285 meta->inode_number = 0; in fill_meta_index()
291 meta_entry = &meta->meta_entry[i - meta->offset]; in fill_meta_index()
292 meta_entry->index_block = cur_index_block - in fill_meta_index()
293 msblk->inode_table; in fill_meta_index()
294 meta_entry->offset = cur_offset; in fill_meta_index()
295 meta_entry->data_block = cur_data_block; in fill_meta_index()
296 meta->entries++; in fill_meta_index()
297 offset++; in fill_meta_index()
300 TRACE("get_meta_index: meta->offset %d, meta->entries %d\n", in fill_meta_index()
301 meta->offset, meta->entries); in fill_meta_index()
314 return offset * SQUASHFS_META_INDEXES * skip; in fill_meta_index()
323 * Get the on-disk location and compressed size of the datablock
330 int offset; in read_blocklist() local
332 int res = fill_meta_index(inode, index, &start, &offset, block); in read_blocklist()
334 TRACE("read_blocklist: res %d, index %d, start 0x%llx, offset" in read_blocklist()
335 " 0x%x, block 0x%llx\n", res, index, start, offset, in read_blocklist()
348 blks = read_indexes(inode->i_sb, index - res, &start, &offset); in read_blocklist()
357 res = squashfs_read_metadata(inode->i_sb, &size, &start, &offset, in read_blocklist()
364 void squashfs_fill_page(struct page *page, struct squashfs_cache_entry *buffer, int offset, int ava… in squashfs_fill_page() argument
369 pageaddr = kmap_atomic(page); in squashfs_fill_page()
370 copied = squashfs_copy_data(pageaddr, buffer, offset, avail); in squashfs_fill_page()
371 memset(pageaddr + copied, 0, PAGE_SIZE - copied); in squashfs_fill_page()
374 flush_dcache_page(page); in squashfs_fill_page()
376 SetPageUptodate(page); in squashfs_fill_page()
378 SetPageError(page); in squashfs_fill_page()
381 /* Copy data into page cache */
382 void squashfs_copy_cache(struct page *page, struct squashfs_cache_entry *buffer, in squashfs_copy_cache() argument
383 int bytes, int offset) in squashfs_copy_cache() argument
385 struct inode *inode = page->mapping->host; in squashfs_copy_cache()
386 struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; in squashfs_copy_cache()
387 int i, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; in squashfs_copy_cache()
388 int start_index = page->index & ~mask, end_index = start_index | mask; in squashfs_copy_cache()
393 * grab the pages from the page cache, except for the page that we've in squashfs_copy_cache()
397 bytes -= PAGE_SIZE, offset += PAGE_SIZE) { in squashfs_copy_cache()
398 struct page *push_page; in squashfs_copy_cache()
403 push_page = (i == page->index) ? page : in squashfs_copy_cache()
404 grab_cache_page_nowait(page->mapping, i); in squashfs_copy_cache()
412 squashfs_fill_page(push_page, buffer, offset, avail); in squashfs_copy_cache()
415 if (i != page->index) in squashfs_copy_cache()
420 /* Read datablock stored packed inside a fragment (tail-end packed block) */
421 static int squashfs_readpage_fragment(struct page *page, int expected) in squashfs_readpage_fragment() argument
423 struct inode *inode = page->mapping->host; in squashfs_readpage_fragment()
424 struct squashfs_cache_entry *buffer = squashfs_get_fragment(inode->i_sb, in squashfs_readpage_fragment()
425 squashfs_i(inode)->fragment_block, in squashfs_readpage_fragment()
426 squashfs_i(inode)->fragment_size); in squashfs_readpage_fragment()
427 int res = buffer->error; in squashfs_readpage_fragment()
430 ERROR("Unable to read page, block %llx, size %x\n", in squashfs_readpage_fragment()
431 squashfs_i(inode)->fragment_block, in squashfs_readpage_fragment()
432 squashfs_i(inode)->fragment_size); in squashfs_readpage_fragment()
434 squashfs_copy_cache(page, buffer, expected, in squashfs_readpage_fragment()
435 squashfs_i(inode)->fragment_offset); in squashfs_readpage_fragment()
441 static int squashfs_readpage_sparse(struct page *page, int expected) in squashfs_readpage_sparse() argument
443 squashfs_copy_cache(page, NULL, expected, 0); in squashfs_readpage_sparse()
447 static int squashfs_readpage(struct file *file, struct page *page) in squashfs_readpage() argument
449 struct inode *inode = page->mapping->host; in squashfs_readpage()
450 struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; in squashfs_readpage()
451 int index = page->index >> (msblk->block_log - PAGE_SHIFT); in squashfs_readpage()
452 int file_end = i_size_read(inode) >> msblk->block_log; in squashfs_readpage()
454 (i_size_read(inode) & (msblk->block_size - 1)) : in squashfs_readpage()
455 msblk->block_size; in squashfs_readpage()
459 TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n", in squashfs_readpage()
460 page->index, squashfs_i(inode)->start); in squashfs_readpage()
462 if (page->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >> in squashfs_readpage()
466 if (index < file_end || squashfs_i(inode)->fragment_block == in squashfs_readpage()
474 res = squashfs_readpage_sparse(page, expected); in squashfs_readpage()
476 res = squashfs_readpage_block(page, block, bsize, expected); in squashfs_readpage()
478 res = squashfs_readpage_fragment(page, expected); in squashfs_readpage()
484 SetPageError(page); in squashfs_readpage()
486 pageaddr = kmap_atomic(page); in squashfs_readpage()
489 flush_dcache_page(page); in squashfs_readpage()
490 if (!PageError(page)) in squashfs_readpage()
491 SetPageUptodate(page); in squashfs_readpage()
492 unlock_page(page); in squashfs_readpage()