Re: Regression: squashfs issues since change "squashfs: migrate from ll_rw_block usage to BIO"
From: Phillip Lougher
Date: Thu Jul 16 2020 - 21:22:39 EST
On Fri, Jul 17, 2020 at 12:07 AM Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, 14 Jul 2020 21:41:07 +0200 Bernd Amend <bernd.amend@xxxxxxxxx> wrote:
>
> > Hi,
> >
> > With the Linux Kernel version 5.8-rc5/master I am unable to mount some
> > squashfs filesystems compressed with "-comp lz4".
> > If I try to mount them I get the following error:
> > [ 1.084246] SQUASHFS error: lz4 decompression failed, data probably corrupt
> > [ 1.084545] SQUASHFS error: Failed to read block 0x873e1001: -5
> > [ 1.084761] SQUASHFS error: Unable to read metadata cache entry [873e0fff]
> > [ 1.084983] SQUASHFS error: Unable to read directory block [873e0fff:1586]
> > [ 1.122564] SQUASHFS error: Unable to read metadata cache entry [873e0fff]
> > [ 1.122708] SQUASHFS error: Unable to read directory block [873e0fff:1586]
> > [ 1.122862] Starting init: /sbin/init exists but couldn't execute
> > it (error -5)
> > [ 1.123027] SQUASHFS error: Unable to read metadata cache entry [873e0fff]
> > [ 1.123152] SQUASHFS error: Unable to read directory block [873e0fff:1586]
> > [ 1.123279] Starting init: /etc/init exists but couldn't execute it
> > (error -5)
> > [ 1.123444] SQUASHFS error: Unable to read metadata cache entry [873e0fff]
> > [ 1.123573] SQUASHFS error: Unable to read directory block [873e0fff:1586]
> > [ 1.123713] Starting init: /bin/init exists but couldn't execute it
> > (error -5)
> > [ 1.123900] SQUASHFS error: Unable to read metadata cache entry [873e0fff]
> >
> > or
> >
> > [ 4960.910693] attempt to access beyond end of device
> > [ 4960.910695] loop0: rw=2048, want=46, limit=40
> > [ 4960.910696] SQUASHFS error: Failed to read block 0x4001: -5
> > [ 4960.910697] SQUASHFS error: Unable to read metadata cache entry [3fff]
> > [ 4960.910698] SQUASHFS error: Unable to read inode 0x20c5000c
> >
> > I bisected the issue to the commit "squashfs: migrate from ll_rw_block
> > usage to BIO"
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/squashfs?id=93e72b3c612adcaca13d874fcc86c53e6c8da541
> >
> > The issue can be reproduced by downloading
> > https://theworldsend.eu/demo.squashfs (20K) and the following command
> > line.
> > # mount demo.squashfs mnt && ls mnt && umount mnt
> >
> > The same squashfs can be mounted using Linux <=5.7.8.
> > The kernel config is identical to the Arch Linux Kernel configuration,
> > build using gcc 9 and 10 on x86_64.
>
> Thanks. I queued a reversion patch. I'll go ahead with this if we are
> unable to get this fixed in the next week or so.
>
Yes, there is a bug in the patch. I have tracked it down today, and I
will send out a fix patch tomorrow.
The bug is here:
+ /* 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) {
This check is wrong, it should be
+ if (offset < bvec->bv_len - 1) {
Phillip
> Are you able to check that the below fixes things up?
>
> Thanks.
>
>
> From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Subject: revert "squashfs: migrate from ll_rw_block usage to BIO"
>
> Revert 93e72b3c612adc ("squashfs: migrate from ll_rw_block usage to BIO")
> due to a regression reported by Bernd Amend.
>
> Link: http://lkml.kernel.org/r/CAF31+H5ZB7zn73obrc5svLzgfsTnyYe5TKvr7-6atUOqrRY+2w@xxxxxxxxxxxxxx
> Reported-by: Bernd Amend <bernd.amend@xxxxxxxxx>
> Cc: Philippe Liard <pliard@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Adrien Schildknecht <adrien+dev@xxxxxxxxxxx>
> Cc: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
> Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>
> Cc: Daniel Rosenberg <drosen@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
>
> fs/squashfs/block.c | 273 ++++++++++------------
> fs/squashfs/decompressor.h | 5
> fs/squashfs/decompressor_multi.c | 9
> fs/squashfs/decompressor_multi_percpu.c | 6
> fs/squashfs/decompressor_single.c | 9
> fs/squashfs/lz4_wrapper.c | 17 -
> fs/squashfs/lzo_wrapper.c | 17 -
> fs/squashfs/squashfs.h | 4
> fs/squashfs/xz_wrapper.c | 51 +---
> fs/squashfs/zlib_wrapper.c | 63 ++---
> fs/squashfs/zstd_wrapper.c | 62 ++--
> 11 files changed, 237 insertions(+), 279 deletions(-)
>
> --- a/fs/squashfs/block.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/block.c
> @@ -13,7 +13,6 @@
> * datablocks and metadata blocks.
> */
>
> -#include <linux/blkdev.h>
> #include <linux/fs.h>
> #include <linux/vfs.h>
> #include <linux/slab.h>
> @@ -28,104 +27,45 @@
> #include "page_actor.h"
>
> /*
> - * Returns the amount of bytes copied to the page actor.
> + * Read the metadata block length, this is stored in the first two
> + * bytes of the metadata block.
> */
> -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)
> +static struct buffer_head *get_block_length(struct super_block *sb,
> + u64 *cur_index, int *offset, int *length)
> {
> struct squashfs_sb_info *msblk = sb->s_fs_info;
> - 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;
> + struct buffer_head *bh;
>
> - 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;
> + 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;
> }
> - offset = 0;
> - total_len -= len;
> }
>
> - 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;
> + return bh;
> }
>
> +
> /*
> * 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
> @@ -136,88 +76,129 @@ out_free_bio:
> * 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 bio *bio = NULL;
> - int compressed;
> - int res;
> - int offset;
> + 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;
>
> 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.
> */
> - const u8 *data;
> - struct bvec_iter_all iter_all = {};
> - struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
> -
> - 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);
> + if ((index + 2) > msblk->bytes_used)
> + goto read_failure;
>
> + bh[0] = get_block_length(sb, &cur_index, &offset, &length);
> + if (bh[0] == NULL)
> + goto read_failure;
> + b = 1;
> +
> + bytes = msblk->devblksize - offset;
> compressed = SQUASHFS_COMPRESSED(length);
> length = SQUASHFS_COMPRESSED_SIZE(length);
> - index += 2;
> + if (next_index)
> + *next_index = index + length + 2;
>
> TRACE("Block @ 0x%llx, %scompressed size %d\n", index,
> - compressed ? "" : "un", length);
> + 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);
> }
> - if (next_index)
> - *next_index = index + length;
>
> - res = squashfs_bio_read(sb, index, length, &bio, &offset);
> - if (res)
> - goto out;
> + for (i = 0; i < b; i++) {
> + wait_on_buffer(bh[i]);
> + if (!buffer_uptodate(bh[i]))
> + goto block_release;
> + }
>
> if (compressed) {
> - if (!msblk->stream) {
> - res = -EIO;
> - goto out_free_bio;
> - }
> - res = squashfs_decompress(msblk, bio, offset, length, output);
> + if (!msblk->stream)
> + goto read_failure;
> + length = squashfs_decompress(msblk, bh, b, offset, length,
> + output);
> + if (length < 0)
> + goto read_failure;
> } else {
> - res = copy_bio_to_actor(bio, output, offset, length);
> + /*
> + * 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]);
> + }
> + squashfs_finish_page(output);
> }
>
> -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);
> + kfree(bh);
> + return length;
>
> - return res;
> +block_release:
> + for (; k < b; k++)
> + put_bh(bh[k]);
> +
> +read_failure:
> + ERROR("squashfs_read_data failed to read block 0x%llx\n",
> + (unsigned long long) index);
> + kfree(bh);
> + return -EIO;
> }
> --- a/fs/squashfs/decompressor.h~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/decompressor.h
> @@ -10,14 +10,13 @@
> * decompressor.h
> */
>
> -#include <linux/bio.h>
> -
> struct squashfs_decompressor {
> void *(*init)(struct squashfs_sb_info *, void *);
> void *(*comp_opts)(struct squashfs_sb_info *, void *, int);
> void (*free)(void *);
> int (*decompress)(struct squashfs_sb_info *, void *,
> - struct bio *, int, int, struct squashfs_page_actor *);
> + struct buffer_head **, int, int, int,
> + struct squashfs_page_actor *);
> int id;
> char *name;
> int supported;
> --- a/fs/squashfs/decompressor_multi.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/decompressor_multi.c
> @@ -6,7 +6,7 @@
> #include <linux/types.h>
> #include <linux/mutex.h>
> #include <linux/slab.h>
> -#include <linux/bio.h>
> +#include <linux/buffer_head.h>
> #include <linux/sched.h>
> #include <linux/wait.h>
> #include <linux/cpumask.h>
> @@ -180,15 +180,14 @@ wait:
> }
>
>
> -int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
> - int offset, int length,
> - struct squashfs_page_actor *output)
> +int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
> + int b, int offset, int length, struct squashfs_page_actor *output)
> {
> int res;
> struct squashfs_stream *stream = msblk->stream;
> struct decomp_stream *decomp_stream = get_decomp_stream(msblk, stream);
> res = msblk->decompressor->decompress(msblk, decomp_stream->stream,
> - bio, offset, length, output);
> + bh, b, offset, length, output);
> put_decomp_stream(decomp_stream, stream);
> if (res < 0)
> ERROR("%s decompression failed, data probably corrupt\n",
> --- a/fs/squashfs/decompressor_multi_percpu.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/decompressor_multi_percpu.c
> @@ -75,8 +75,8 @@ void squashfs_decompressor_destroy(struc
> }
> }
>
> -int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
> - int offset, int length, struct squashfs_page_actor *output)
> +int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
> + int b, int offset, int length, struct squashfs_page_actor *output)
> {
> struct squashfs_stream *stream;
> int res;
> @@ -84,7 +84,7 @@ int squashfs_decompress(struct squashfs_
> local_lock(&msblk->stream->lock);
> stream = this_cpu_ptr(msblk->stream);
>
> - res = msblk->decompressor->decompress(msblk, stream->stream, bio,
> + res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
> offset, length, output);
>
> local_unlock(&msblk->stream->lock);
> --- a/fs/squashfs/decompressor_single.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/decompressor_single.c
> @@ -7,7 +7,7 @@
> #include <linux/types.h>
> #include <linux/mutex.h>
> #include <linux/slab.h>
> -#include <linux/bio.h>
> +#include <linux/buffer_head.h>
>
> #include "squashfs_fs.h"
> #include "squashfs_fs_sb.h"
> @@ -59,15 +59,14 @@ void squashfs_decompressor_destroy(struc
> }
> }
>
> -int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
> - int offset, int length,
> - struct squashfs_page_actor *output)
> +int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
> + int b, int offset, int length, struct squashfs_page_actor *output)
> {
> int res;
> struct squashfs_stream *stream = msblk->stream;
>
> mutex_lock(&stream->mutex);
> - res = msblk->decompressor->decompress(msblk, stream->stream, bio,
> + res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
> offset, length, output);
> mutex_unlock(&stream->mutex);
>
> --- a/fs/squashfs/lz4_wrapper.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/lz4_wrapper.c
> @@ -4,7 +4,7 @@
> * Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
> */
>
> -#include <linux/bio.h>
> +#include <linux/buffer_head.h>
> #include <linux/mutex.h>
> #include <linux/slab.h>
> #include <linux/vmalloc.h>
> @@ -89,23 +89,20 @@ static void lz4_free(void *strm)
>
>
> static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm,
> - struct bio *bio, int offset, int length,
> + struct buffer_head **bh, int b, int offset, int length,
> struct squashfs_page_actor *output)
> {
> - struct bvec_iter_all iter_all = {};
> - struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
> struct squashfs_lz4 *stream = strm;
> void *buff = stream->input, *data;
> - int bytes = length, res;
> + int avail, i, bytes = length, res;
>
> - while (bio_next_segment(bio, &iter_all)) {
> - int avail = min(bytes, ((int)bvec->bv_len) - offset);
> -
> - data = page_address(bvec->bv_page) + bvec->bv_offset;
> - memcpy(buff, data + offset, avail);
> + for (i = 0; i < b; i++) {
> + avail = min(bytes, msblk->devblksize - offset);
> + memcpy(buff, bh[i]->b_data + offset, avail);
> buff += avail;
> bytes -= avail;
> offset = 0;
> + put_bh(bh[i]);
> }
>
> res = LZ4_decompress_safe(stream->input, stream->output,
> --- a/fs/squashfs/lzo_wrapper.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/lzo_wrapper.c
> @@ -9,7 +9,7 @@
> */
>
> #include <linux/mutex.h>
> -#include <linux/bio.h>
> +#include <linux/buffer_head.h>
> #include <linux/slab.h>
> #include <linux/vmalloc.h>
> #include <linux/lzo.h>
> @@ -63,24 +63,21 @@ static void lzo_free(void *strm)
>
>
> static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
> - struct bio *bio, int offset, int length,
> + struct buffer_head **bh, int b, int offset, int length,
> struct squashfs_page_actor *output)
> {
> - struct bvec_iter_all iter_all = {};
> - struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
> struct squashfs_lzo *stream = strm;
> void *buff = stream->input, *data;
> - int bytes = length, res;
> + int avail, i, bytes = length, res;
> size_t out_len = output->length;
>
> - while (bio_next_segment(bio, &iter_all)) {
> - int avail = min(bytes, ((int)bvec->bv_len) - offset);
> -
> - data = page_address(bvec->bv_page) + bvec->bv_offset;
> - memcpy(buff, data + offset, avail);
> + for (i = 0; i < b; i++) {
> + avail = min(bytes, msblk->devblksize - offset);
> + memcpy(buff, bh[i]->b_data + offset, avail);
> buff += avail;
> bytes -= avail;
> offset = 0;
> + put_bh(bh[i]);
> }
>
> res = lzo1x_decompress_safe(stream->input, (size_t)length,
> --- a/fs/squashfs/squashfs.h~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/squashfs.h
> @@ -40,8 +40,8 @@ extern void *squashfs_decompressor_setup
> /* decompressor_xxx.c */
> extern void *squashfs_decompressor_create(struct squashfs_sb_info *, void *);
> extern void squashfs_decompressor_destroy(struct squashfs_sb_info *);
> -extern int squashfs_decompress(struct squashfs_sb_info *, struct bio *,
> - int, int, struct squashfs_page_actor *);
> +extern int squashfs_decompress(struct squashfs_sb_info *, struct buffer_head **,
> + int, int, int, struct squashfs_page_actor *);
> extern int squashfs_max_decompressors(void);
>
> /* export.c */
> --- a/fs/squashfs/xz_wrapper.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/xz_wrapper.c
> @@ -10,7 +10,7 @@
>
>
> #include <linux/mutex.h>
> -#include <linux/bio.h>
> +#include <linux/buffer_head.h>
> #include <linux/slab.h>
> #include <linux/xz.h>
> #include <linux/bitops.h>
> @@ -117,12 +117,11 @@ static void squashfs_xz_free(void *strm)
>
>
> static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
> - struct bio *bio, int offset, int length,
> + struct buffer_head **bh, int b, int offset, int length,
> struct squashfs_page_actor *output)
> {
> - struct bvec_iter_all iter_all = {};
> - struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
> - int total = 0, error = 0;
> + enum xz_ret xz_err;
> + int avail, total = 0, k = 0;
> struct squashfs_xz *stream = strm;
>
> xz_dec_reset(stream->state);
> @@ -132,23 +131,11 @@ static int squashfs_xz_uncompress(struct
> stream->buf.out_size = PAGE_SIZE;
> stream->buf.out = squashfs_first_page(output);
>
> - for (;;) {
> - enum xz_ret xz_err;
> -
> - if (stream->buf.in_pos == stream->buf.in_size) {
> - const void *data;
> - int avail;
> -
> - if (!bio_next_segment(bio, &iter_all)) {
> - /* XZ_STREAM_END must be reached. */
> - error = -EIO;
> - break;
> - }
> -
> - avail = min(length, ((int)bvec->bv_len) - offset);
> - data = page_address(bvec->bv_page) + bvec->bv_offset;
> + do {
> + if (stream->buf.in_pos == stream->buf.in_size && k < b) {
> + avail = min(length, msblk->devblksize - offset);
> length -= avail;
> - stream->buf.in = data + offset;
> + stream->buf.in = bh[k]->b_data + offset;
> stream->buf.in_size = avail;
> stream->buf.in_pos = 0;
> offset = 0;
> @@ -163,17 +150,23 @@ static int squashfs_xz_uncompress(struct
> }
>
> xz_err = xz_dec_run(stream->state, &stream->buf);
> - if (xz_err == XZ_STREAM_END)
> - break;
> - if (xz_err != XZ_OK) {
> - error = -EIO;
> - break;
> - }
> - }
> +
> + if (stream->buf.in_pos == stream->buf.in_size && k < b)
> + put_bh(bh[k++]);
> + } while (xz_err == XZ_OK);
>
> squashfs_finish_page(output);
>
> - return error ? error : total + stream->buf.out_pos;
> + if (xz_err != XZ_STREAM_END || k < b)
> + goto out;
> +
> + return total + stream->buf.out_pos;
> +
> +out:
> + for (; k < b; k++)
> + put_bh(bh[k]);
> +
> + return -EIO;
> }
>
> const struct squashfs_decompressor squashfs_xz_comp_ops = {
> --- a/fs/squashfs/zlib_wrapper.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/zlib_wrapper.c
> @@ -10,7 +10,7 @@
>
>
> #include <linux/mutex.h>
> -#include <linux/bio.h>
> +#include <linux/buffer_head.h>
> #include <linux/slab.h>
> #include <linux/zlib.h>
> #include <linux/vmalloc.h>
> @@ -50,35 +50,21 @@ static void zlib_free(void *strm)
>
>
> static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm,
> - struct bio *bio, int offset, int length,
> + struct buffer_head **bh, int b, int offset, int length,
> struct squashfs_page_actor *output)
> {
> - struct bvec_iter_all iter_all = {};
> - struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
> - int zlib_init = 0, error = 0;
> + int zlib_err, zlib_init = 0, k = 0;
> z_stream *stream = strm;
>
> stream->avail_out = PAGE_SIZE;
> stream->next_out = squashfs_first_page(output);
> stream->avail_in = 0;
>
> - for (;;) {
> - int zlib_err;
> -
> - if (stream->avail_in == 0) {
> - const void *data;
> - int avail;
> -
> - if (!bio_next_segment(bio, &iter_all)) {
> - /* Z_STREAM_END must be reached. */
> - error = -EIO;
> - break;
> - }
> -
> - avail = min(length, ((int)bvec->bv_len) - offset);
> - data = page_address(bvec->bv_page) + bvec->bv_offset;
> + do {
> + if (stream->avail_in == 0 && k < b) {
> + int avail = min(length, msblk->devblksize - offset);
> length -= avail;
> - stream->next_in = data + offset;
> + stream->next_in = bh[k]->b_data + offset;
> stream->avail_in = avail;
> offset = 0;
> }
> @@ -92,28 +78,37 @@ static int zlib_uncompress(struct squash
> if (!zlib_init) {
> zlib_err = zlib_inflateInit(stream);
> if (zlib_err != Z_OK) {
> - error = -EIO;
> - break;
> + squashfs_finish_page(output);
> + goto out;
> }
> zlib_init = 1;
> }
>
> zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
> - if (zlib_err == Z_STREAM_END)
> - break;
> - if (zlib_err != Z_OK) {
> - error = -EIO;
> - break;
> - }
> - }
> +
> + if (stream->avail_in == 0 && k < b)
> + put_bh(bh[k++]);
> + } while (zlib_err == Z_OK);
>
> squashfs_finish_page(output);
>
> - if (!error)
> - if (zlib_inflateEnd(stream) != Z_OK)
> - error = -EIO;
> + if (zlib_err != Z_STREAM_END)
> + goto out;
> +
> + zlib_err = zlib_inflateEnd(stream);
> + if (zlib_err != Z_OK)
> + goto out;
> +
> + if (k < b)
> + goto out;
> +
> + return stream->total_out;
> +
> +out:
> + for (; k < b; k++)
> + put_bh(bh[k]);
>
> - return error ? error : stream->total_out;
> + return -EIO;
> }
>
> const struct squashfs_decompressor squashfs_zlib_comp_ops = {
> --- a/fs/squashfs/zstd_wrapper.c~revert-squashfs-migrate-from-ll_rw_block-usage-to-bio
> +++ a/fs/squashfs/zstd_wrapper.c
> @@ -9,7 +9,7 @@
> */
>
> #include <linux/mutex.h>
> -#include <linux/bio.h>
> +#include <linux/buffer_head.h>
> #include <linux/slab.h>
> #include <linux/zstd.h>
> #include <linux/vmalloc.h>
> @@ -59,44 +59,33 @@ static void zstd_free(void *strm)
>
>
> static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm,
> - struct bio *bio, int offset, int length,
> + struct buffer_head **bh, int b, int offset, int length,
> struct squashfs_page_actor *output)
> {
> struct workspace *wksp = strm;
> ZSTD_DStream *stream;
> size_t total_out = 0;
> - int error = 0;
> + size_t zstd_err;
> + int k = 0;
> ZSTD_inBuffer in_buf = { NULL, 0, 0 };
> ZSTD_outBuffer out_buf = { NULL, 0, 0 };
> - struct bvec_iter_all iter_all = {};
> - struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
>
> stream = ZSTD_initDStream(wksp->window_size, wksp->mem, wksp->mem_size);
>
> if (!stream) {
> ERROR("Failed to initialize zstd decompressor\n");
> - return -EIO;
> + goto out;
> }
>
> out_buf.size = PAGE_SIZE;
> out_buf.dst = squashfs_first_page(output);
>
> - for (;;) {
> - size_t zstd_err;
> + do {
> + if (in_buf.pos == in_buf.size && k < b) {
> + int avail = min(length, msblk->devblksize - offset);
>
> - if (in_buf.pos == in_buf.size) {
> - const void *data;
> - int avail;
> -
> - if (!bio_next_segment(bio, &iter_all)) {
> - error = -EIO;
> - break;
> - }
> -
> - avail = min(length, ((int)bvec->bv_len) - offset);
> - data = page_address(bvec->bv_page) + bvec->bv_offset;
> length -= avail;
> - in_buf.src = data + offset;
> + in_buf.src = bh[k]->b_data + offset;
> in_buf.size = avail;
> in_buf.pos = 0;
> offset = 0;
> @@ -108,8 +97,8 @@ static int zstd_uncompress(struct squash
> /* Shouldn't run out of pages
> * before stream is done.
> */
> - error = -EIO;
> - break;
> + squashfs_finish_page(output);
> + goto out;
> }
> out_buf.pos = 0;
> out_buf.size = PAGE_SIZE;
> @@ -118,20 +107,29 @@ static int zstd_uncompress(struct squash
> total_out -= out_buf.pos;
> zstd_err = ZSTD_decompressStream(stream, &out_buf, &in_buf);
> total_out += out_buf.pos; /* add the additional data produced */
> - if (zstd_err == 0)
> - break;
>
> - if (ZSTD_isError(zstd_err)) {
> - ERROR("zstd decompression error: %d\n",
> - (int)ZSTD_getErrorCode(zstd_err));
> - error = -EIO;
> - break;
> - }
> - }
> + if (in_buf.pos == in_buf.size && k < b)
> + put_bh(bh[k++]);
> + } while (zstd_err != 0 && !ZSTD_isError(zstd_err));
>
> squashfs_finish_page(output);
>
> - return error ? error : total_out;
> + if (ZSTD_isError(zstd_err)) {
> + ERROR("zstd decompression error: %d\n",
> + (int)ZSTD_getErrorCode(zstd_err));
> + goto out;
> + }
> +
> + if (k < b)
> + goto out;
> +
> + return (int)total_out;
> +
> +out:
> + for (; k < b; k++)
> + put_bh(bh[k]);
> +
> + return -EIO;
> }
>
> const struct squashfs_decompressor squashfs_zstd_comp_ops = {
> _
>