[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/squashfs/file_direct.c b/src/kernel/linux/v4.14/fs/squashfs/file_direct.c
new file mode 100644
index 0000000..dc87f77
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/squashfs/file_direct.c
@@ -0,0 +1,156 @@
+/*
+ * 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 <linux/mm_inline.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+#include "page_actor.h"
+
+static void release_actor_pages(struct page **page, int pages, int error)
+{
+ int i;
+
+ for (i = 0; i < pages; i++) {
+ if (!page[i])
+ continue;
+ flush_dcache_page(page[i]);
+ if (!error)
+ SetPageUptodate(page[i]);
+ else {
+ SetPageError(page[i]);
+ zero_user_segment(page[i], 0, PAGE_SIZE);
+ }
+ unlock_page(page[i]);
+ put_page(page[i]);
+ }
+ kfree(page);
+}
+
+/*
+ * Create a "page actor" which will kmap and kunmap the
+ * page cache pages appropriately within the decompressor
+ */
+static struct squashfs_page_actor *actor_from_page_cache(
+ unsigned int actor_pages, struct page *target_page,
+ struct list_head *rpages, unsigned int *nr_pages, int start_index,
+ struct address_space *mapping)
+{
+ struct page **page;
+ struct squashfs_page_actor *actor;
+ int i, n;
+ gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
+
+ page = kmalloc_array(actor_pages, sizeof(void *), GFP_KERNEL);
+ if (!page)
+ return NULL;
+
+ for (i = 0, n = start_index; i < actor_pages; i++, n++) {
+ if (target_page == NULL && rpages && !list_empty(rpages)) {
+ struct page *cur_page = lru_to_page(rpages);
+
+ if (cur_page->index < start_index + actor_pages) {
+ list_del(&cur_page->lru);
+ --(*nr_pages);
+ if (add_to_page_cache_lru(cur_page, mapping,
+ cur_page->index, gfp))
+ put_page(cur_page);
+ else
+ target_page = cur_page;
+ } else
+ rpages = NULL;
+ }
+
+ if (target_page && target_page->index == n) {
+ page[i] = target_page;
+ target_page = NULL;
+ } else {
+ page[i] = grab_cache_page_nowait(mapping, n);
+ if (page[i] == NULL)
+ continue;
+ }
+
+ if (PageUptodate(page[i])) {
+ unlock_page(page[i]);
+ put_page(page[i]);
+ page[i] = NULL;
+ }
+ }
+
+ actor = squashfs_page_actor_init(page, actor_pages, 0,
+ release_actor_pages);
+ if (!actor) {
+ release_actor_pages(page, actor_pages, -ENOMEM);
+ kfree(page);
+ return NULL;
+ }
+ return actor;
+}
+
+int squashfs_readpages_block(struct page *target_page,
+ struct list_head *readahead_pages,
+ unsigned int *nr_pages,
+ struct address_space *mapping,
+ int page_index, u64 block, int bsize)
+
+{
+ struct squashfs_page_actor *actor;
+ struct inode *inode = mapping->host;
+ struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+ int start_index, end_index, file_end, actor_pages, res;
+ int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
+
+ /*
+ * If readpage() is called on an uncompressed datablock, we can just
+ * read the pages instead of fetching the whole block.
+ * This greatly improves the performance when a process keep doing
+ * random reads because we only fetch the necessary data.
+ * The readahead algorithm will take care of doing speculative reads
+ * if necessary.
+ * We can't read more than 1 block even if readahead provides use more
+ * pages because we don't know yet if the next block is compressed or
+ * not.
+ */
+ if (bsize && !SQUASHFS_COMPRESSED_BLOCK(bsize)) {
+ u64 block_end = block + msblk->block_size;
+
+ block += (page_index & mask) * PAGE_SIZE;
+ actor_pages = (block_end - block) / PAGE_SIZE;
+ if (*nr_pages < actor_pages)
+ actor_pages = *nr_pages;
+ start_index = page_index;
+ bsize = min_t(int, bsize, (PAGE_SIZE * actor_pages)
+ | SQUASHFS_COMPRESSED_BIT_BLOCK);
+ } else {
+ file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT;
+ start_index = page_index & ~mask;
+ end_index = start_index | mask;
+ if (end_index > file_end)
+ end_index = file_end;
+ actor_pages = end_index - start_index + 1;
+ }
+
+ actor = actor_from_page_cache(actor_pages, target_page,
+ readahead_pages, nr_pages, start_index,
+ mapping);
+ if (!actor)
+ return -ENOMEM;
+
+ res = squashfs_read_data_async(inode->i_sb, block, bsize, NULL,
+ actor);
+ return res < 0 ? res : 0;
+}