* datablocks and metadata blocks.
*/
+#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include "page_actor.h"
/*
- * Read the metadata block length, this is stored in the first two
- * bytes of the metadata block.
+ * Returns the amount of bytes copied to the page actor.
*/
-static struct buffer_head *get_block_length(struct super_block *sb,
- u64 *cur_index, int *offset, int *length)
+static int copy_bio_to_actor(struct bio *bio,
+ struct squashfs_page_actor *actor,
+ int offset, int req_length)
+{
+ void *actor_addr = squashfs_first_page(actor);
+ struct bvec_iter_all iter_all = {};
+ struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
+ int copied_bytes = 0;
+ int actor_offset = 0;
+
+ if (WARN_ON_ONCE(!bio_next_segment(bio, &iter_all)))
+ return 0;
+
+ while (copied_bytes < req_length) {
+ int bytes_to_copy = min_t(int, bvec->bv_len - offset,
+ PAGE_SIZE - actor_offset);
+
+ bytes_to_copy = min_t(int, bytes_to_copy,
+ req_length - copied_bytes);
+ memcpy(actor_addr + actor_offset,
+ page_address(bvec->bv_page) + bvec->bv_offset + offset,
+ bytes_to_copy);
+
+ actor_offset += bytes_to_copy;
+ copied_bytes += bytes_to_copy;
+ offset += bytes_to_copy;
+
+ if (actor_offset >= PAGE_SIZE) {
+ actor_addr = squashfs_next_page(actor);
+ if (!actor_addr)
+ break;
+ actor_offset = 0;
+ }
+ if (offset >= bvec->bv_len) {
+ if (!bio_next_segment(bio, &iter_all))
+ break;
+ offset = 0;
+ }
+ }
+ squashfs_finish_page(actor);
+ return copied_bytes;
+}
+
+static int squashfs_bio_read(struct super_block *sb, u64 index, int length,
+ struct bio **biop, int *block_offset)
{
struct squashfs_sb_info *msblk = sb->s_fs_info;
- struct buffer_head *bh;
-
- bh = sb_bread(sb, *cur_index);
- if (bh == NULL)
- return NULL;
-
- if (msblk->devblksize - *offset == 1) {
- *length = (unsigned char) bh->b_data[*offset];
- put_bh(bh);
- bh = sb_bread(sb, ++(*cur_index));
- if (bh == NULL)
- return NULL;
- *length |= (unsigned char) bh->b_data[0] << 8;
- *offset = 1;
- } else {
- *length = (unsigned char) bh->b_data[*offset] |
- (unsigned char) bh->b_data[*offset + 1] << 8;
- *offset += 2;
-
- if (*offset == msblk->devblksize) {
- put_bh(bh);
- bh = sb_bread(sb, ++(*cur_index));
- if (bh == NULL)
- return NULL;
- *offset = 0;
+ const u64 read_start = round_down(index, msblk->devblksize);
+ const sector_t block = read_start >> msblk->devblksize_log2;
+ const u64 read_end = round_up(index + length, msblk->devblksize);
+ const sector_t block_end = read_end >> msblk->devblksize_log2;
+ int offset = read_start - round_down(index, PAGE_SIZE);
+ int total_len = (block_end - block) << msblk->devblksize_log2;
+ const int page_count = DIV_ROUND_UP(total_len + offset, PAGE_SIZE);
+ int error, i;
+ struct bio *bio;
+
+ bio = bio_alloc(GFP_NOIO, page_count);
+ if (!bio)
+ return -ENOMEM;
+
+ bio_set_dev(bio, sb->s_bdev);
+ bio->bi_opf = READ;
+ bio->bi_iter.bi_sector = block * (msblk->devblksize >> SECTOR_SHIFT);
+
+ for (i = 0; i < page_count; ++i) {
+ unsigned int len =
+ min_t(unsigned int, PAGE_SIZE - offset, total_len);
+ struct page *page = alloc_page(GFP_NOIO);
+
+ if (!page) {
+ error = -ENOMEM;
+ goto out_free_bio;
+ }
+ if (!bio_add_page(bio, page, len, offset)) {
+ error = -EIO;
+ goto out_free_bio;
}
+ offset = 0;
+ total_len -= len;
}
- return bh;
-}
+ error = submit_bio_wait(bio);
+ if (error)
+ goto out_free_bio;
+ *biop = bio;
+ *block_offset = index & ((1 << msblk->devblksize_log2) - 1);
+ return 0;
+
+out_free_bio:
+ bio_free_pages(bio);
+ bio_put(bio);
+ return error;
+}
/*
* Read and decompress a metadata block or datablock. Length is non-zero
* algorithms).
*/
int squashfs_read_data(struct super_block *sb, u64 index, int length,
- u64 *next_index, struct squashfs_page_actor *output)
+ u64 *next_index, struct squashfs_page_actor *output)
{
struct squashfs_sb_info *msblk = sb->s_fs_info;
- struct buffer_head **bh;
- int offset = index & ((1 << msblk->devblksize_log2) - 1);
- u64 cur_index = index >> msblk->devblksize_log2;
- int bytes, compressed, b = 0, k = 0, avail, i;
-
- bh = kcalloc(((output->length + msblk->devblksize - 1)
- >> msblk->devblksize_log2) + 1, sizeof(*bh), GFP_KERNEL);
- if (bh == NULL)
- return -ENOMEM;
+ struct bio *bio = NULL;
+ int compressed;
+ int res;
+ int offset;
if (length) {
/*
* Datablock.
*/
- bytes = -offset;
compressed = SQUASHFS_COMPRESSED_BLOCK(length);
length = SQUASHFS_COMPRESSED_SIZE_BLOCK(length);
- if (next_index)
- *next_index = index + length;
-
TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n",
index, compressed ? "" : "un", length, output->length);
-
- if (length < 0 || length > output->length ||
- (index + length) > msblk->bytes_used)
- goto read_failure;
-
- for (b = 0; bytes < length; b++, cur_index++) {
- bh[b] = sb_getblk(sb, cur_index);
- if (bh[b] == NULL)
- goto block_release;
- bytes += msblk->devblksize;
- }
- ll_rw_block(REQ_OP_READ, 0, b, bh);
} else {
/*
* Metadata block.
*/
- if ((index + 2) > msblk->bytes_used)
- goto read_failure;
+ const u8 *data;
+ struct bvec_iter_all iter_all = {};
+ struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
- bh[0] = get_block_length(sb, &cur_index, &offset, &length);
- if (bh[0] == NULL)
- goto read_failure;
- b = 1;
+ if (index + 2 > msblk->bytes_used) {
+ res = -EIO;
+ goto out;
+ }
+ res = squashfs_bio_read(sb, index, 2, &bio, &offset);
+ if (res)
+ goto out;
+
+ if (WARN_ON_ONCE(!bio_next_segment(bio, &iter_all))) {
+ res = -EIO;
+ goto out_free_bio;
+ }
+ /* Extract the length of the metadata block */
+ data = page_address(bvec->bv_page) + bvec->bv_offset;
+ length = data[offset];
+ if (offset <= bvec->bv_len - 1) {
+ length |= data[offset + 1] << 8;
+ } else {
+ if (WARN_ON_ONCE(!bio_next_segment(bio, &iter_all))) {
+ res = -EIO;
+ goto out_free_bio;
+ }
+ data = page_address(bvec->bv_page) + bvec->bv_offset;
+ length |= data[0] << 8;
+ }
+ bio_free_pages(bio);
+ bio_put(bio);
- bytes = msblk->devblksize - offset;
compressed = SQUASHFS_COMPRESSED(length);
length = SQUASHFS_COMPRESSED_SIZE(length);
- if (next_index)
- *next_index = index + length + 2;
+ index += 2;
TRACE("Block @ 0x%llx, %scompressed size %d\n", index,
- compressed ? "" : "un", length);
-
- if (length < 0 || length > output->length ||
- (index + length) > msblk->bytes_used)
- goto block_release;
-
- for (; bytes < length; b++) {
- bh[b] = sb_getblk(sb, ++cur_index);
- if (bh[b] == NULL)
- goto block_release;
- bytes += msblk->devblksize;
- }
- ll_rw_block(REQ_OP_READ, 0, b - 1, bh + 1);
+ compressed ? "" : "un", length);
}
+ if (next_index)
+ *next_index = index + length;
- for (i = 0; i < b; i++) {
- wait_on_buffer(bh[i]);
- if (!buffer_uptodate(bh[i]))
- goto block_release;
- }
+ res = squashfs_bio_read(sb, index, length, &bio, &offset);
+ if (res)
+ goto out;
if (compressed) {
- if (!msblk->stream)
- goto read_failure;
- length = squashfs_decompress(msblk, bh, b, offset, length,
- output);
- if (length < 0)
- goto read_failure;
- } else {
- /*
- * Block is uncompressed.
- */
- int in, pg_offset = 0;
- void *data = squashfs_first_page(output);
-
- for (bytes = length; k < b; k++) {
- in = min(bytes, msblk->devblksize - offset);
- bytes -= in;
- while (in) {
- if (pg_offset == PAGE_SIZE) {
- data = squashfs_next_page(output);
- pg_offset = 0;
- }
- avail = min_t(int, in, PAGE_SIZE -
- pg_offset);
- memcpy(data + pg_offset, bh[k]->b_data + offset,
- avail);
- in -= avail;
- pg_offset += avail;
- offset += avail;
- }
- offset = 0;
- put_bh(bh[k]);
+ if (!msblk->stream) {
+ res = -EIO;
+ goto out_free_bio;
}
- squashfs_finish_page(output);
+ res = squashfs_decompress(msblk, bio, offset, length, output);
+ } else {
+ res = copy_bio_to_actor(bio, output, offset, length);
}
- kfree(bh);
- return length;
-
-block_release:
- for (; k < b; k++)
- put_bh(bh[k]);
+out_free_bio:
+ bio_free_pages(bio);
+ bio_put(bio);
+out:
+ if (res < 0)
+ ERROR("Failed to read block 0x%llx: %d\n", index, res);
-read_failure:
- ERROR("squashfs_read_data failed to read block 0x%llx\n",
- (unsigned long long) index);
- kfree(bh);
- return -EIO;
+ return res;
}
projects / linux-2.6-microblaze.git / blobdiff