diff options
Diffstat (limited to 'fs/squashfs/file_direct.c')
-rw-r--r-- | fs/squashfs/file_direct.c | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c deleted file mode 100644 index 62a0de6..0000000 --- a/fs/squashfs/file_direct.c +++ /dev/null @@ -1,176 +0,0 @@ -/* - * Copyright (c) 2013 - * Phillip Lougher <phillip@squashfs.org.uk> - * - * This work is licensed under the terms of the GNU GPL, version 2. See - * the COPYING file in the top-level directory. - */ - -#include <linux/fs.h> -#include <linux/vfs.h> -#include <linux/kernel.h> -#include <linux/slab.h> -#include <linux/string.h> -#include <linux/pagemap.h> -#include <linux/mutex.h> - -#include "squashfs_fs.h" -#include "squashfs_fs_sb.h" -#include "squashfs_fs_i.h" -#include "squashfs.h" -#include "page_actor.h" - -static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, - int pages, struct page **page); - -/* Read separately compressed datablock directly into page cache */ -int squashfs_readpage_block(struct page *target_page, u64 block, int bsize) - -{ - struct inode *inode = target_page->mapping->host; - struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; - - int file_end = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT; - int mask = (1 << (msblk->block_log - PAGE_CACHE_SHIFT)) - 1; - int start_index = target_page->index & ~mask; - int end_index = start_index | mask; - int i, n, pages, missing_pages, bytes, res = -ENOMEM; - struct page **page; - struct squashfs_page_actor *actor; - void *pageaddr; - - if (end_index > file_end) - end_index = file_end; - - pages = end_index - start_index + 1; - - page = kmalloc(sizeof(void *) * pages, GFP_KERNEL); - if (page == NULL) - return res; - - /* - * Create a "page actor" which will kmap and kunmap the - * page cache pages appropriately within the decompressor - */ - actor = squashfs_page_actor_init_special(page, pages, 0); - if (actor == NULL) - goto out; - - /* Try to grab all the pages covered by the Squashfs block */ - for (missing_pages = 0, i = 0, n = start_index; i < pages; i++, n++) { - page[i] = (n == target_page->index) ? target_page : - grab_cache_page_nowait(target_page->mapping, n); - - if (page[i] == NULL) { - missing_pages++; - continue; - } - - if (PageUptodate(page[i])) { - unlock_page(page[i]); - page_cache_release(page[i]); - page[i] = NULL; - missing_pages++; - } - } - - if (missing_pages) { - /* - * Couldn't get one or more pages, this page has either - * been VM reclaimed, but others are still in the page cache - * and uptodate, or we're racing with another thread in - * squashfs_readpage also trying to grab them. Fall back to - * using an intermediate buffer. - */ - res = squashfs_read_cache(target_page, block, bsize, pages, - page); - if (res < 0) - goto mark_errored; - - goto out; - } - - /* Decompress directly into the page cache buffers */ - res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor); - if (res < 0) - goto mark_errored; - - /* Last page may have trailing bytes not filled */ - bytes = res % PAGE_CACHE_SIZE; - if (bytes) { - pageaddr = kmap_atomic(page[pages - 1]); - memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes); - kunmap_atomic(pageaddr); - } - - /* Mark pages as uptodate, unlock and release */ - for (i = 0; i < pages; i++) { - flush_dcache_page(page[i]); - SetPageUptodate(page[i]); - unlock_page(page[i]); - if (page[i] != target_page) - page_cache_release(page[i]); - } - - kfree(actor); - kfree(page); - - return 0; - -mark_errored: - /* Decompression failed, mark pages as errored. Target_page is - * dealt with by the caller - */ - for (i = 0; i < pages; i++) { - if (page[i] == NULL || page[i] == target_page) - continue; - flush_dcache_page(page[i]); - SetPageError(page[i]); - unlock_page(page[i]); - page_cache_release(page[i]); - } - -out: - kfree(actor); - kfree(page); - return res; -} - - -static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, - int pages, struct page **page) -{ - struct inode *i = target_page->mapping->host; - struct squashfs_cache_entry *buffer = squashfs_get_datablock(i->i_sb, - block, bsize); - int bytes = buffer->length, res = buffer->error, n, offset = 0; - void *pageaddr; - - if (res) { - ERROR("Unable to read page, block %llx, size %x\n", block, - bsize); - goto out; - } - - for (n = 0; n < pages && bytes > 0; n++, - bytes -= PAGE_CACHE_SIZE, offset += PAGE_CACHE_SIZE) { - int avail = min_t(int, bytes, PAGE_CACHE_SIZE); - - if (page[n] == NULL) - continue; - - pageaddr = kmap_atomic(page[n]); - squashfs_copy_data(pageaddr, buffer, offset, avail); - memset(pageaddr + avail, 0, PAGE_CACHE_SIZE - avail); - kunmap_atomic(pageaddr); - flush_dcache_page(page[n]); - SetPageUptodate(page[n]); - unlock_page(page[n]); - if (page[n] != target_page) - page_cache_release(page[n]); - } - -out: - squashfs_cache_put(buffer); - return res; -} |