[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/squashfs/block.c b/src/kernel/linux/v4.14/fs/squashfs/block.c
new file mode 100644
index 0000000..dfc2e76
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/squashfs/block.c
@@ -0,0 +1,477 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * block.c
+ */
+
+/*
+ * This file implements the low-level routines to read and decompress
+ * datablocks and metadata blocks.
+ */
+
+#include <linux/fs.h>
+#include <linux/vfs.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/pagemap.h>
+#include <linux/buffer_head.h>
+#include <linux/bio.h>
+#include <linux/workqueue.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs.h"
+#include "decompressor.h"
+#include "page_actor.h"
+
+static struct workqueue_struct *squashfs_read_wq;
+
+struct squashfs_read_request {
+ struct super_block *sb;
+ u64 index;
+ int length;
+ int compressed;
+ int offset;
+ u64 read_end;
+ struct squashfs_page_actor *output;
+ enum {
+ SQUASHFS_COPY,
+ SQUASHFS_DECOMPRESS,
+ SQUASHFS_METADATA,
+ } data_processing;
+ bool synchronous;
+
+ /*
+ * If the read is synchronous, it is possible to retrieve information
+ * about the request by setting these pointers.
+ */
+ int *res;
+ int *bytes_read;
+ int *bytes_uncompressed;
+
+ int nr_buffers;
+ struct buffer_head **bh;
+ struct work_struct offload;
+};
+
+struct squashfs_bio_request {
+ struct buffer_head **bh;
+ int nr_buffers;
+};
+
+static int squashfs_bio_submit(struct squashfs_read_request *req);
+
+int squashfs_init_read_wq(void)
+{
+ squashfs_read_wq = create_workqueue("SquashFS read wq");
+ return !!squashfs_read_wq;
+}
+
+void squashfs_destroy_read_wq(void)
+{
+ flush_workqueue(squashfs_read_wq);
+ destroy_workqueue(squashfs_read_wq);
+}
+
+static void free_read_request(struct squashfs_read_request *req, int error)
+{
+ if (!req->synchronous)
+ squashfs_page_actor_free(req->output, error);
+ if (req->res)
+ *(req->res) = error;
+ kfree(req->bh);
+ kfree(req);
+}
+
+static void squashfs_process_blocks(struct squashfs_read_request *req)
+{
+ int error = 0;
+ int bytes, i, length;
+ struct squashfs_sb_info *msblk = req->sb->s_fs_info;
+ struct squashfs_page_actor *actor = req->output;
+ struct buffer_head **bh = req->bh;
+ int nr_buffers = req->nr_buffers;
+
+ for (i = 0; i < nr_buffers; ++i) {
+ if (!bh[i])
+ continue;
+ wait_on_buffer(bh[i]);
+ if (!buffer_uptodate(bh[i]))
+ error = -EIO;
+ }
+ if (error)
+ goto cleanup;
+
+ if (req->data_processing == SQUASHFS_METADATA) {
+ /* Extract the length of the metadata block */
+ if (req->offset != msblk->devblksize - 1) {
+ length = le16_to_cpup((__le16 *)
+ (bh[0]->b_data + req->offset));
+ } else {
+ length = (unsigned char)bh[0]->b_data[req->offset];
+ length |= (unsigned char)bh[1]->b_data[0] << 8;
+ }
+ req->compressed = SQUASHFS_COMPRESSED(length);
+ req->data_processing = req->compressed ? SQUASHFS_DECOMPRESS
+ : SQUASHFS_COPY;
+ length = SQUASHFS_COMPRESSED_SIZE(length);
+ if (req->index + length + 2 > req->read_end) {
+ for (i = 0; i < nr_buffers; ++i)
+ put_bh(bh[i]);
+ kfree(bh);
+ req->length = length;
+ req->index += 2;
+ squashfs_bio_submit(req);
+ return;
+ }
+ req->length = length;
+ req->offset = (req->offset + 2) % PAGE_SIZE;
+ if (req->offset < 2) {
+ put_bh(bh[0]);
+ ++bh;
+ --nr_buffers;
+ }
+ }
+ if (req->bytes_read)
+ *(req->bytes_read) = req->length;
+
+ if (req->data_processing == SQUASHFS_COPY) {
+ squashfs_bh_to_actor(bh, nr_buffers, req->output, req->offset,
+ req->length, msblk->devblksize);
+ } else if (req->data_processing == SQUASHFS_DECOMPRESS) {
+ req->length = squashfs_decompress(msblk, bh, nr_buffers,
+ req->offset, req->length, actor);
+ if (req->length < 0) {
+ error = -EIO;
+ goto cleanup;
+ }
+ }
+
+ /* Last page may have trailing bytes not filled */
+ bytes = req->length % PAGE_SIZE;
+ if (bytes && actor->page[actor->pages - 1])
+ zero_user_segment(actor->page[actor->pages - 1], bytes,
+ PAGE_SIZE);
+
+cleanup:
+ if (req->bytes_uncompressed)
+ *(req->bytes_uncompressed) = req->length;
+ if (error) {
+ for (i = 0; i < nr_buffers; ++i)
+ if (bh[i])
+ put_bh(bh[i]);
+ }
+ free_read_request(req, error);
+}
+
+static void read_wq_handler(struct work_struct *work)
+{
+ squashfs_process_blocks(container_of(work,
+ struct squashfs_read_request, offload));
+}
+
+static void squashfs_bio_end_io(struct bio *bio)
+{
+ int i;
+ blk_status_t error = bio->bi_status;
+ struct squashfs_bio_request *bio_req = bio->bi_private;
+
+ bio_put(bio);
+
+ for (i = 0; i < bio_req->nr_buffers; ++i) {
+ if (!bio_req->bh[i])
+ continue;
+ if (!error)
+ set_buffer_uptodate(bio_req->bh[i]);
+ else
+ clear_buffer_uptodate(bio_req->bh[i]);
+ unlock_buffer(bio_req->bh[i]);
+ }
+ kfree(bio_req);
+}
+
+static int bh_is_optional(struct squashfs_read_request *req, int idx)
+{
+ int start_idx, end_idx;
+ struct squashfs_sb_info *msblk = req->sb->s_fs_info;
+
+ start_idx = (idx * msblk->devblksize - req->offset) >> PAGE_SHIFT;
+ end_idx = ((idx + 1) * msblk->devblksize - req->offset + 1) >> PAGE_SHIFT;
+ if (start_idx >= req->output->pages)
+ return 1;
+ if (start_idx < 0)
+ start_idx = end_idx;
+ if (end_idx >= req->output->pages)
+ end_idx = start_idx;
+ return !req->output->page[start_idx] && !req->output->page[end_idx];
+}
+
+static int actor_getblks(struct squashfs_read_request *req, u64 block)
+{
+ int i;
+
+ req->bh = kmalloc_array(req->nr_buffers, sizeof(*(req->bh)), GFP_NOIO);
+ if (!req->bh)
+ return -ENOMEM;
+
+ for (i = 0; i < req->nr_buffers; ++i) {
+ /*
+ * When dealing with an uncompressed block, the actor may
+ * contains NULL pages. There's no need to read the buffers
+ * associated with these pages.
+ */
+ if (!req->compressed && bh_is_optional(req, i)) {
+ req->bh[i] = NULL;
+ continue;
+ }
+ req->bh[i] = sb_getblk(req->sb, block + i);
+ if (!req->bh[i]) {
+ while (--i) {
+ if (req->bh[i])
+ put_bh(req->bh[i]);
+ }
+ return -1;
+ }
+ }
+ return 0;
+}
+
+static int squashfs_bio_submit(struct squashfs_read_request *req)
+{
+ struct bio *bio = NULL;
+ struct buffer_head *bh;
+ struct squashfs_bio_request *bio_req = NULL;
+ int b = 0, prev_block = 0;
+ struct squashfs_sb_info *msblk = req->sb->s_fs_info;
+
+ u64 read_start = round_down(req->index, msblk->devblksize);
+ u64 read_end = round_up(req->index + req->length, msblk->devblksize);
+ sector_t block = read_start >> msblk->devblksize_log2;
+ sector_t block_end = read_end >> msblk->devblksize_log2;
+ int offset = read_start - round_down(req->index, PAGE_SIZE);
+ int nr_buffers = block_end - block;
+ int blksz = msblk->devblksize;
+ int bio_max_pages = nr_buffers > BIO_MAX_PAGES ? BIO_MAX_PAGES
+ : nr_buffers;
+
+ /* Setup the request */
+ req->read_end = read_end;
+ req->offset = req->index - read_start;
+ req->nr_buffers = nr_buffers;
+ if (actor_getblks(req, block) < 0)
+ goto getblk_failed;
+
+ /* Create and submit the BIOs */
+ for (b = 0; b < nr_buffers; ++b, offset += blksz) {
+ bh = req->bh[b];
+ if (!bh || !trylock_buffer(bh))
+ continue;
+ if (buffer_uptodate(bh)) {
+ unlock_buffer(bh);
+ continue;
+ }
+ offset %= PAGE_SIZE;
+
+ /* Append the buffer to the current BIO if it is contiguous */
+ if (bio && bio_req && prev_block + 1 == b) {
+ if (bio_add_page(bio, bh->b_page, blksz, offset)) {
+ bio_req->nr_buffers += 1;
+ prev_block = b;
+ continue;
+ }
+ }
+
+ /* Otherwise, submit the current BIO and create a new one */
+ if (bio)
+ submit_bio(bio);
+ bio_req = kcalloc(1, sizeof(struct squashfs_bio_request),
+ GFP_NOIO);
+ if (!bio_req)
+ goto req_alloc_failed;
+ bio_req->bh = &req->bh[b];
+ bio = bio_alloc(GFP_NOIO, bio_max_pages);
+ if (!bio)
+ goto bio_alloc_failed;
+ bio_set_dev(bio, req->sb->s_bdev);
+ bio->bi_iter.bi_sector = (block + b)
+ << (msblk->devblksize_log2 - 9);
+ bio_set_op_attrs(bio, REQ_OP_READ, 0);
+ bio->bi_private = bio_req;
+ bio->bi_end_io = squashfs_bio_end_io;
+
+ bio_add_page(bio, bh->b_page, blksz, offset);
+ bio_req->nr_buffers += 1;
+ prev_block = b;
+ }
+ if (bio)
+ submit_bio(bio);
+
+ if (req->synchronous)
+ squashfs_process_blocks(req);
+ else {
+ INIT_WORK(&req->offload, read_wq_handler);
+ schedule_work(&req->offload);
+ }
+ return 0;
+
+bio_alloc_failed:
+ kfree(bio_req);
+req_alloc_failed:
+ unlock_buffer(bh);
+ while (--nr_buffers >= b)
+ if (req->bh[nr_buffers])
+ put_bh(req->bh[nr_buffers]);
+ while (--b >= 0)
+ if (req->bh[b])
+ wait_on_buffer(req->bh[b]);
+getblk_failed:
+ free_read_request(req, -ENOMEM);
+ return -ENOMEM;
+}
+
+static int read_metadata_block(struct squashfs_read_request *req,
+ u64 *next_index)
+{
+ int ret, error, bytes_read = 0, bytes_uncompressed = 0;
+ struct squashfs_sb_info *msblk = req->sb->s_fs_info;
+
+ if (req->index + 2 > msblk->bytes_used) {
+ free_read_request(req, -EINVAL);
+ return -EINVAL;
+ }
+ req->length = 2;
+
+ /* Do not read beyond the end of the device */
+ if (req->index + req->length > msblk->bytes_used)
+ req->length = msblk->bytes_used - req->index;
+ req->data_processing = SQUASHFS_METADATA;
+
+ /*
+ * Reading metadata is always synchronous because we don't know the
+ * length in advance and the function is expected to update
+ * 'next_index' and return the length.
+ */
+ req->synchronous = true;
+ req->res = &error;
+ req->bytes_read = &bytes_read;
+ req->bytes_uncompressed = &bytes_uncompressed;
+
+ TRACE("Metadata block @ 0x%llx, %scompressed size %d, src size %d\n",
+ req->index, req->compressed ? "" : "un", bytes_read,
+ req->output->length);
+
+ ret = squashfs_bio_submit(req);
+ if (ret)
+ return ret;
+ if (error)
+ return error;
+ if (next_index)
+ *next_index += 2 + bytes_read;
+ return bytes_uncompressed;
+}
+
+static int read_data_block(struct squashfs_read_request *req, int length,
+ u64 *next_index, bool synchronous)
+{
+ int ret, error = 0, bytes_uncompressed = 0, bytes_read = 0;
+
+ req->compressed = SQUASHFS_COMPRESSED_BLOCK(length);
+ req->length = length = SQUASHFS_COMPRESSED_SIZE_BLOCK(length);
+ req->data_processing = req->compressed ? SQUASHFS_DECOMPRESS
+ : SQUASHFS_COPY;
+
+ req->synchronous = synchronous;
+ if (synchronous) {
+ req->res = &error;
+ req->bytes_read = &bytes_read;
+ req->bytes_uncompressed = &bytes_uncompressed;
+ }
+
+ TRACE("Data block @ 0x%llx, %scompressed size %d, src size %d\n",
+ req->index, req->compressed ? "" : "un", req->length,
+ req->output->length);
+
+ ret = squashfs_bio_submit(req);
+ if (ret)
+ return ret;
+ if (synchronous)
+ ret = error ? error : bytes_uncompressed;
+ if (next_index)
+ *next_index += length;
+ return ret;
+}
+
+/*
+ * Read and decompress a metadata block or datablock. Length is non-zero
+ * if a datablock is being read (the size is stored elsewhere in the
+ * filesystem), otherwise the length is obtained from the first two bytes of
+ * the metadata block. A bit in the length field indicates if the block
+ * is stored uncompressed in the filesystem (usually because compression
+ * generated a larger block - this does occasionally happen with compression
+ * algorithms).
+ */
+static int __squashfs_read_data(struct super_block *sb, u64 index, int length,
+ u64 *next_index, struct squashfs_page_actor *output, bool sync)
+{
+ struct squashfs_read_request *req;
+
+ req = kcalloc(1, sizeof(struct squashfs_read_request), GFP_KERNEL);
+ if (!req) {
+ if (!sync)
+ squashfs_page_actor_free(output, -ENOMEM);
+ return -ENOMEM;
+ }
+
+ req->sb = sb;
+ req->index = index;
+ req->output = output;
+
+ if (next_index)
+ *next_index = index;
+
+ if (length)
+ length = read_data_block(req, length, next_index, sync);
+ else
+ length = read_metadata_block(req, next_index);
+
+ if (length < 0) {
+ ERROR("squashfs_read_data failed to read block 0x%llx\n",
+ (unsigned long long)index);
+ return -EIO;
+ }
+
+ return length;
+}
+
+int squashfs_read_data(struct super_block *sb, u64 index, int length,
+ u64 *next_index, struct squashfs_page_actor *output)
+{
+ return __squashfs_read_data(sb, index, length, next_index, output,
+ true);
+}
+
+int squashfs_read_data_async(struct super_block *sb, u64 index, int length,
+ u64 *next_index, struct squashfs_page_actor *output)
+{
+
+ return __squashfs_read_data(sb, index, length, next_index, output,
+ false);
+}