[PATCH 1/6] Squashfs: Refactor decompressor interface and code (V2)
The decompressor interface and code was written from
the point of view of single-threaded operation. In doing
so it mixed a lot of single-threaded implementation specific
aspects into the decompressor code and elsewhere which makes it
difficult to seamlessly support multiple different decompressor
implementations.
This patch does the following:
1. It removes compressor_options parsing from the decompressor
init() function. This allows the decompressor init() function
to be dynamically called to instantiate multiple decompressors,
without the compressor options needing to be read and parsed each
time.
2. It moves threading and all sleeping operations out of the
decompressors. In doing so, it makes the decompressors
non-blocking wrappers which only deal with interfacing with
the decompressor implementation.
3. It splits decompressor.[ch] into decompressor generic functions
in decompressor.[ch], and moves the single threaded
decompressor implementation into decompressor_single.c.
The result of this patch is Squashfs should now be able to
support multiple decompressors by adding new decompressor_xxx.c
files with specialised implementations of the functions in
decompressor_single.c
V2:
* decompressor_single.c: Shorten header comment by removing GPL licence text
* decompressor_single.c: Remove comp_opts from struct squashfs_stream,
it's not needed in this implementation
* Fix checkpatch.pl errors
Signed-off-by: Phillip Lougher
Reviewed-by: Minchan Kim
---
fs/squashfs/Makefile |2 +-
fs/squashfs/block.c | 11 +++--
fs/squashfs/decompressor.c| 47 +---
fs/squashfs/decompressor.h| 21 +++--
fs/squashfs/decompressor_single.c | 86 +++
fs/squashfs/lzo_wrapper.c | 24 +++---
fs/squashfs/squashfs.h|9 +++-
fs/squashfs/squashfs_fs_sb.h |3 +-
fs/squashfs/super.c | 10 ++---
fs/squashfs/xz_wrapper.c | 89 -
fs/squashfs/zlib_wrapper.c| 50 +++--
11 files changed, 216 insertions(+), 136 deletions(-)
create mode 100644 fs/squashfs/decompressor_single.c
diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index 110b047..c223c84 100644
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -4,7 +4,7 @@
obj-$(CONFIG_SQUASHFS) += squashfs.o
squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
-squashfs-y += namei.o super.o symlink.o decompressor.o
+squashfs-y += namei.o super.o symlink.o decompressor.o decompressor_single.o
squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 41d108e..4dd4025 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -93,7 +93,7 @@ int squashfs_read_data(struct super_block *sb, void **buffer,
u64 index,
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, page = 0, avail;
+ int bytes, compressed, b = 0, k = 0, page = 0, avail, i;
bh = kcalloc(((srclength + msblk->devblksize - 1)
>> msblk->devblksize_log2) + 1, sizeof(*bh), GFP_KERNEL);
@@ -158,6 +158,12 @@ int squashfs_read_data(struct super_block *sb, void
**buffer, u64 index,
ll_rw_block(READ, b - 1, bh + 1);
}
+ for (i = 0; i < b; i++) {
+ wait_on_buffer(bh[i]);
+ if (!buffer_uptodate(bh[i]))
+ goto block_release;
+ }
+
if (compressed) {
length = squashfs_decompress(msblk, buffer, bh, b, offset,
length, srclength, pages);
@@ -172,9 +178,6 @@ int squashfs_read_data(struct super_block *sb, void
**buffer, u64 index,
for (bytes = length; k < b; k++) {
in = min(bytes, msblk->devblksize - offset);
bytes -= in;
- wait_on_buffer(bh[k]);
- if (!buffer_uptodate(bh[k]))
- goto block_release;
while (in) {
if (pg_offset == PAGE_CACHE_SIZE) {
page++;
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index 3f6271d..234291f 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -37,29 +37,29 @@
*/
static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops =
{
- NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
+ NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
};
#ifndef CONFIG_SQUASHFS_LZO
static const struct squashfs_decompressor
[PATCH 1/6] Squashfs: Refactor decompressor interface and code (V2)
The decompressor interface and code was written from
the point of view of single-threaded operation. In doing
so it mixed a lot of single-threaded implementation specific
aspects into the decompressor code and elsewhere which makes it
difficult to seamlessly support multiple different decompressor
implementations.
This patch does the following:
1. It removes compressor_options parsing from the decompressor
init() function. This allows the decompressor init() function
to be dynamically called to instantiate multiple decompressors,
without the compressor options needing to be read and parsed each
time.
2. It moves threading and all sleeping operations out of the
decompressors. In doing so, it makes the decompressors
non-blocking wrappers which only deal with interfacing with
the decompressor implementation.
3. It splits decompressor.[ch] into decompressor generic functions
in decompressor.[ch], and moves the single threaded
decompressor implementation into decompressor_single.c.
The result of this patch is Squashfs should now be able to
support multiple decompressors by adding new decompressor_xxx.c
files with specialised implementations of the functions in
decompressor_single.c
V2:
* decompressor_single.c: Shorten header comment by removing GPL licence text
* decompressor_single.c: Remove comp_opts from struct squashfs_stream,
it's not needed in this implementation
* Fix checkpatch.pl errors
Signed-off-by: Phillip Lougher phil...@squashfs.org.uk
Reviewed-by: Minchan Kim minc...@kernel.org
---
fs/squashfs/Makefile |2 +-
fs/squashfs/block.c | 11 +++--
fs/squashfs/decompressor.c| 47 +---
fs/squashfs/decompressor.h| 21 +++--
fs/squashfs/decompressor_single.c | 86 +++
fs/squashfs/lzo_wrapper.c | 24 +++---
fs/squashfs/squashfs.h|9 +++-
fs/squashfs/squashfs_fs_sb.h |3 +-
fs/squashfs/super.c | 10 ++---
fs/squashfs/xz_wrapper.c | 89 -
fs/squashfs/zlib_wrapper.c| 50 +++--
11 files changed, 216 insertions(+), 136 deletions(-)
create mode 100644 fs/squashfs/decompressor_single.c
diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index 110b047..c223c84 100644
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -4,7 +4,7 @@
obj-$(CONFIG_SQUASHFS) += squashfs.o
squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
-squashfs-y += namei.o super.o symlink.o decompressor.o
+squashfs-y += namei.o super.o symlink.o decompressor.o decompressor_single.o
squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 41d108e..4dd4025 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -93,7 +93,7 @@ int squashfs_read_data(struct super_block *sb, void **buffer,
u64 index,
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, page = 0, avail;
+ int bytes, compressed, b = 0, k = 0, page = 0, avail, i;
bh = kcalloc(((srclength + msblk-devblksize - 1)
msblk-devblksize_log2) + 1, sizeof(*bh), GFP_KERNEL);
@@ -158,6 +158,12 @@ int squashfs_read_data(struct super_block *sb, void
**buffer, u64 index,
ll_rw_block(READ, b - 1, bh + 1);
}
+ for (i = 0; i b; i++) {
+ wait_on_buffer(bh[i]);
+ if (!buffer_uptodate(bh[i]))
+ goto block_release;
+ }
+
if (compressed) {
length = squashfs_decompress(msblk, buffer, bh, b, offset,
length, srclength, pages);
@@ -172,9 +178,6 @@ int squashfs_read_data(struct super_block *sb, void
**buffer, u64 index,
for (bytes = length; k b; k++) {
in = min(bytes, msblk-devblksize - offset);
bytes -= in;
- wait_on_buffer(bh[k]);
- if (!buffer_uptodate(bh[k]))
- goto block_release;
while (in) {
if (pg_offset == PAGE_CACHE_SIZE) {
page++;
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index 3f6271d..234291f 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -37,29 +37,29 @@
*/
static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops =
{
- NULL, NULL, NULL, LZMA_COMPRESSION, lzma, 0
+ NULL, NULL, NULL, NULL, LZMA_COMPRESSION, lzma, 0
};
#ifndef CONFIG_SQUASHFS_LZO
static const struct
