[PATCH v3] squashfs: Migrate from ll_rw_block usage to BIO

From: Philippe Liard
Date: Wed Nov 06 2019 - 02:43:27 EST

The ll_rw_block() function has been deprecated in favor of BIO which
appears to come with large performance improvements.

This patch decreases boot time by close to 40% when using squashfs for
the root file-system. This is observed at least in the context of
starting an Android VM on Chrome OS using crosvm
(https://chromium.googlesource.com/chromiumos/platform/crosvm). The
patch was tested on 4.19 as well as master.

This patch is largely based on Adrien Schildknecht's patch that was
originally sent as https://lkml.org/lkml/2017/9/22/814 though with some
significant changes and simplifications while also taking Phillip
Lougher's feedback into account, around preserving support for
FILE_CACHE in particular.

Signed-off-by: Philippe Liard <pliard@xxxxxxxxxx>
---
Changes in v3:
- BIO iterators are used rather than using private bio fields
- removed bio_read_context struct

Changes in v2:
- changed all decompressors to take a bio pointer
- removed usage of buffer_head in block.c

arch/x86/configs/x86_64_arcvm_defconfig | 3 +
fs/squashfs/block.c | 273 +++++++++++++-----------
fs/squashfs/decompressor.h | 5 +-
fs/squashfs/decompressor_multi.c | 9 +-
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 | 64 +++---
11 files changed, 280 insertions(+), 235 deletions(-)

diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index f098b9f1c396..119345510033 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -26,6 +26,7 @@
* datablocks and metadata blocks.
*/

+#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.h>
@@ -40,44 +41,103 @@
#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
@@ -89,129 +149,88 @@ static struct buffer_head *get_block_length(struct super_block *sb,
* 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;
}
diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h
index 0f5a8e4e58da..420fedd82f14 100644
--- a/fs/squashfs/decompressor.h
+++ b/fs/squashfs/decompressor.h
@@ -23,13 +23,14 @@
* 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 buffer_head **, int, int, int,
- struct squashfs_page_actor *);
+ struct bio *, int, int, struct squashfs_page_actor *);
int id;
char *name;
int supported;
diff --git a/fs/squashfs/decompressor_multi.c b/fs/squashfs/decompressor_multi.c
index d6008a636479..0bf1ac0f554e 100644
--- a/fs/squashfs/decompressor_multi.c
+++ b/fs/squashfs/decompressor_multi.c
@@ -8,7 +8,7 @@
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/slab.h>
-#include <linux/buffer_head.h>
+#include <linux/bio.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/cpumask.h>
@@ -182,14 +182,15 @@ static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk,
}


-int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
- int b, int offset, int length, struct squashfs_page_actor *output)
+int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
+ 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,
- bh, b, offset, length, output);
+ bio, offset, length, output);
put_decomp_stream(decomp_stream, stream);
if (res < 0)
ERROR("%s decompression failed, data probably corrupt\n",
diff --git a/fs/squashfs/decompressor_single.c b/fs/squashfs/decompressor_single.c
index a6c75929a00e..43dcfeadc33e 100644
--- a/fs/squashfs/decompressor_single.c
+++ b/fs/squashfs/decompressor_single.c
@@ -9,7 +9,7 @@
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/slab.h>
-#include <linux/buffer_head.h>
+#include <linux/bio.h>

#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
@@ -61,14 +61,15 @@ void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
}
}

-int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
- int b, int offset, int length, struct squashfs_page_actor *output)
+int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
+ 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, bh, b,
+ res = msblk->decompressor->decompress(msblk, stream->stream, bio,
offset, length, output);
mutex_unlock(&stream->mutex);

diff --git a/fs/squashfs/lz4_wrapper.c b/fs/squashfs/lz4_wrapper.c
index 95da65366548..62264dadb38a 100644
--- a/fs/squashfs/lz4_wrapper.c
+++ b/fs/squashfs/lz4_wrapper.c
@@ -6,7 +6,7 @@
* the COPYING file in the top-level directory.
*/

-#include <linux/buffer_head.h>
+#include <linux/bio.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -91,20 +91,23 @@ static void lz4_free(void *strm)


static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm,
- struct buffer_head **bh, int b, int offset, int length,
+ struct bio *bio, 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 avail, i, bytes = length, res;
+ int bytes = length, res;

- for (i = 0; i < b; i++) {
- avail = min(bytes, msblk->devblksize - offset);
- memcpy(buff, bh[i]->b_data + offset, avail);
+ 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);
buff += avail;
bytes -= avail;
offset = 0;
- put_bh(bh[i]);
}

res = LZ4_decompress_safe(stream->input, stream->output,
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
index 934c17e96590..4bd3c80053d9 100644
--- a/fs/squashfs/lzo_wrapper.c
+++ b/fs/squashfs/lzo_wrapper.c
@@ -22,7 +22,7 @@
*/

#include <linux/mutex.h>
-#include <linux/buffer_head.h>
+#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/lzo.h>
@@ -76,21 +76,24 @@ static void lzo_free(void *strm)


static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
- struct buffer_head **bh, int b, int offset, int length,
+ struct bio *bio, 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 avail, i, bytes = length, res;
+ int bytes = length, res;
size_t out_len = output->length;

- for (i = 0; i < b; i++) {
- avail = min(bytes, msblk->devblksize - offset);
- memcpy(buff, bh[i]->b_data + offset, avail);
+ 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);
buff += avail;
bytes -= avail;
offset = 0;
- put_bh(bh[i]);
}

res = lzo1x_decompress_safe(stream->input, (size_t)length,
diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index f89f8a74c6ce..b2f2c1fa2d17 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -53,8 +53,8 @@ extern void *squashfs_decompressor_setup(struct super_block *, unsigned short);
/* 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 buffer_head **,
- int, int, int, struct squashfs_page_actor *);
+extern int squashfs_decompress(struct squashfs_sb_info *, struct bio *,
+ int, int, struct squashfs_page_actor *);
extern int squashfs_max_decompressors(void);

/* export.c */
diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c
index 6bfaef73d065..5bb3dc42144f 100644
--- a/fs/squashfs/xz_wrapper.c
+++ b/fs/squashfs/xz_wrapper.c
@@ -23,7 +23,7 @@


#include <linux/mutex.h>
-#include <linux/buffer_head.h>
+#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/xz.h>
#include <linux/bitops.h>
@@ -130,11 +130,12 @@ static void squashfs_xz_free(void *strm)


static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
- struct buffer_head **bh, int b, int offset, int length,
+ struct bio *bio, int offset, int length,
struct squashfs_page_actor *output)
{
- enum xz_ret xz_err;
- int avail, total = 0, k = 0;
+ struct bvec_iter_all iter_all = {};
+ struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
+ int total = 0, error = 0;
struct squashfs_xz *stream = strm;

xz_dec_reset(stream->state);
@@ -144,11 +145,23 @@ static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
stream->buf.out_size = PAGE_SIZE;
stream->buf.out = squashfs_first_page(output);

- do {
- if (stream->buf.in_pos == stream->buf.in_size && k < b) {
- avail = min(length, msblk->devblksize - offset);
+ 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;
length -= avail;
- stream->buf.in = bh[k]->b_data + offset;
+ stream->buf.in = data + offset;
stream->buf.in_size = avail;
stream->buf.in_pos = 0;
offset = 0;
@@ -163,23 +176,17 @@ static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
}

xz_err = xz_dec_run(stream->state, &stream->buf);
-
- if (stream->buf.in_pos == stream->buf.in_size && k < b)
- put_bh(bh[k++]);
- } while (xz_err == XZ_OK);
+ if (xz_err == XZ_STREAM_END)
+ break;
+ if (xz_err != XZ_OK) {
+ error = -EIO;
+ break;
+ }
+ }

squashfs_finish_page(output);

- 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;
+ return error ? error : total + stream->buf.out_pos;
}

const struct squashfs_decompressor squashfs_xz_comp_ops = {
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 2ec24d128bce..08ae721184a6 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -23,7 +23,7 @@


#include <linux/mutex.h>
-#include <linux/buffer_head.h>
+#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/zlib.h>
#include <linux/vmalloc.h>
@@ -63,21 +63,35 @@ static void zlib_free(void *strm)


static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm,
- struct buffer_head **bh, int b, int offset, int length,
+ struct bio *bio, int offset, int length,
struct squashfs_page_actor *output)
{
- int zlib_err, zlib_init = 0, k = 0;
+ struct bvec_iter_all iter_all = {};
+ struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
+ int zlib_init = 0, error = 0;
z_stream *stream = strm;

stream->avail_out = PAGE_SIZE;
stream->next_out = squashfs_first_page(output);
stream->avail_in = 0;

- do {
- if (stream->avail_in == 0 && k < b) {
- int avail = min(length, msblk->devblksize - offset);
+ 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;
length -= avail;
- stream->next_in = bh[k]->b_data + offset;
+ stream->next_in = data + offset;
stream->avail_in = avail;
offset = 0;
}
@@ -91,37 +105,28 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm,
if (!zlib_init) {
zlib_err = zlib_inflateInit(stream);
if (zlib_err != Z_OK) {
- squashfs_finish_page(output);
- goto out;
+ error = -EIO;
+ break;
}
zlib_init = 1;
}

zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
-
- if (stream->avail_in == 0 && k < b)
- put_bh(bh[k++]);
- } while (zlib_err == Z_OK);
+ if (zlib_err == Z_STREAM_END)
+ break;
+ if (zlib_err != Z_OK) {
+ error = -EIO;
+ break;
+ }
+ }

squashfs_finish_page(output);

- 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]);
+ if (!error)
+ if (zlib_inflateEnd(stream) != Z_OK)
+ error = -EIO;

- return -EIO;
+ return error ? error : stream->total_out;
}

const struct squashfs_decompressor squashfs_zlib_comp_ops = {
diff --git a/fs/squashfs/zstd_wrapper.c b/fs/squashfs/zstd_wrapper.c
index eeaabf881159..43166b74bc59 100644
--- a/fs/squashfs/zstd_wrapper.c
+++ b/fs/squashfs/zstd_wrapper.c
@@ -18,7 +18,7 @@
*/

#include <linux/mutex.h>
-#include <linux/buffer_head.h>
+#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/zstd.h>
#include <linux/vmalloc.h>
@@ -68,33 +68,44 @@ static void zstd_free(void *strm)


static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm,
- struct buffer_head **bh, int b, int offset, int length,
+ struct bio *bio, int offset, int length,
struct squashfs_page_actor *output)
{
struct workspace *wksp = strm;
ZSTD_DStream *stream;
size_t total_out = 0;
- size_t zstd_err;
- int k = 0;
+ int error = 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");
- goto out;
+ return -EIO;
}

out_buf.size = PAGE_SIZE;
out_buf.dst = squashfs_first_page(output);

- do {
- if (in_buf.pos == in_buf.size && k < b) {
- int avail = min(length, msblk->devblksize - offset);
+ for (;;) {
+ size_t zstd_err;

+ 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 = bh[k]->b_data + offset;
+ in_buf.src = data + offset;
in_buf.size = avail;
in_buf.pos = 0;
offset = 0;
@@ -106,8 +117,8 @@ static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm,
/* Shouldn't run out of pages
* before stream is done.
*/
- squashfs_finish_page(output);
- goto out;
+ error = -EIO;
+ break;
}
out_buf.pos = 0;
out_buf.size = PAGE_SIZE;
@@ -116,29 +127,20 @@ static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm,
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 (in_buf.pos == in_buf.size && k < b)
- put_bh(bh[k++]);
- } while (zstd_err != 0 && !ZSTD_isError(zstd_err));
-
- squashfs_finish_page(output);
-
- if (ZSTD_isError(zstd_err)) {
- ERROR("zstd decompression error: %d\n",
- (int)ZSTD_getErrorCode(zstd_err));
- goto out;
+ 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 (k < b)
- goto out;
-
- return (int)total_out;
-
-out:
- for (; k < b; k++)
- put_bh(bh[k]);
+ squashfs_finish_page(output);

- return -EIO;
+ return error ? error : total_out;
}

const struct squashfs_decompressor squashfs_zstd_comp_ops = {
--
2.24.0.rc1.363.gb1bccd3e3d-goog