| Message ID | 20200811131755.22396-3-joaomarcos.costa@bootlin.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Tom Rini |
| Headers | show |
| Series | fs/squashfs: Add new decompression algorithms | expand |
On Tue, 11 Aug 2020 15:17:55 +0200 Joao Marcos Costa <joaomarcos.costa@bootlin.com> wrote: > +#if IS_ENABLED(CONFIG_ZSTD) > +static int sqfs_zstd_decompress(void *dest, unsigned long dest_len, > + void *source, u32 src_len) > +{ > + void *workspace; > + ZSTD_DCtx *ctx; > + size_t wsize; > + int ret; > + > + wsize = ZSTD_DCtxWorkspaceBound(); So apparently this "workspace" has a constant size, which does not depend on the size of the input buffer. Correct ? If that's the case, can we instead allocate it once for all in sqfs_probe() if the filesystem is zstd-compressed ? I.e perhaps sqfs_probe() could call a sqfs_decompressor_init() function, implemented in sqfs_decompressor.c, which will do this sort of initialization. And of course this memory area would be freed up in sqfs_close(), calling a sqfs_decompressor_{deinit,cleanup,close} function. Best regards, Thomas
On Tue, 11 Aug 2020 15:29:51 +0200 Thomas Petazzoni <thomas.petazzoni@bootlin.com> wrote: > On Tue, 11 Aug 2020 15:17:55 +0200 > Joao Marcos Costa <joaomarcos.costa@bootlin.com> wrote: > > > +#if IS_ENABLED(CONFIG_ZSTD) > > +static int sqfs_zstd_decompress(void *dest, unsigned long dest_len, > > + void *source, u32 src_len) > > +{ > > + void *workspace; > > + ZSTD_DCtx *ctx; > > + size_t wsize; > > + int ret; > > + > > + wsize = ZSTD_DCtxWorkspaceBound(); > > So apparently this "workspace" has a constant size, which does not > depend on the size of the input buffer. Correct ? Yes, correct. > If that's the case, can we instead allocate it once for all in > sqfs_probe() if the filesystem is zstd-compressed ? I.e perhaps > sqfs_probe() could call a sqfs_decompressor_init() function, > implemented in sqfs_decompressor.c, which will do this sort of > initialization. And of course this memory area would be freed up in > sqfs_close(), calling a sqfs_decompressor_{deinit,cleanup,close} > function. Sure, it can be done. I will prepare a v2 addressing your suggestion. Thanks! > Best regards, > > Thomas Best regards, Joao
diff --git a/fs/squashfs/sqfs_decompressor.c b/fs/squashfs/sqfs_decompressor.c index 9285df5d3b..b5a9d92808 100644 --- a/fs/squashfs/sqfs_decompressor.c +++ b/fs/squashfs/sqfs_decompressor.c @@ -18,6 +18,10 @@ #include <u-boot/zlib.h> #endif +#if IS_ENABLED(CONFIG_ZSTD) +#include <linux/zstd.h> +#endif + #include "sqfs_decompressor.h" #include "sqfs_filesystem.h" #include "sqfs_utils.h" @@ -39,6 +43,31 @@ static void zlib_decompression_status(int ret) } #endif +#if IS_ENABLED(CONFIG_ZSTD) +static int sqfs_zstd_decompress(void *dest, unsigned long dest_len, + void *source, u32 src_len) +{ + void *workspace; + ZSTD_DCtx *ctx; + size_t wsize; + int ret; + + wsize = ZSTD_DCtxWorkspaceBound(); + + workspace = malloc(wsize); + if (!workspace) + return -ENOMEM; + + ctx = ZSTD_initDCtx(workspace, wsize); + + ret = ZSTD_decompressDCtx(ctx, dest, dest_len, source, src_len); + + free(workspace); + + return ZSTD_isError(ret); +} +#endif /* CONFIG_ZSTD */ + int sqfs_decompress(u16 comp_type, void *dest, unsigned long *dest_len, void *source, u32 src_len) { @@ -67,6 +96,16 @@ int sqfs_decompress(u16 comp_type, void *dest, unsigned long *dest_len, break; } #endif +#if IS_ENABLED(CONFIG_ZSTD) + case SQFS_COMP_ZSTD: + ret = sqfs_zstd_decompress(dest, *dest_len, source, src_len); + if (ret) { + printf("ZSTD Error code: %d\n", ZSTD_getErrorCode(ret)); + return -EINVAL; + } + + break; +#endif /* CONFIG_ZSTD */ default: printf("Error: unknown compression type.\n"); return -EINVAL;
Add call to ZSTD's ZSTD_decompressDCtx(). In this use case, the caller can upper bound the decompressed size, which will be the SquashFS data block (or metadata block) size, so there is no need to use streaming API. Signed-off-by: Joao Marcos Costa <joaomarcos.costa@bootlin.com> --- fs/squashfs/sqfs_decompressor.c | 39 +++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+)