fs/squashfs: add support for ZSTD decompression
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. Add ZSTD's worskpace to squashfs_ctxt structure.
Signed-off-by: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
diff --git a/fs/squashfs/sqfs_decompressor.c b/fs/squashfs/sqfs_decompressor.c
index cf388ac..9457ee5 100644
--- a/fs/squashfs/sqfs_decompressor.c
+++ b/fs/squashfs/sqfs_decompressor.c
@@ -13,6 +13,10 @@
#include <u-boot/zlib.h>
#endif
+#if IS_ENABLED(CONFIG_ZSTD)
+#include <linux/zstd.h>
+#endif
+
#include "sqfs_decompressor.h"
#include "sqfs_utils.h"
@@ -25,6 +29,13 @@
case SQFS_COMP_ZLIB:
break;
#endif
+#if IS_ENABLED(CONFIG_ZSTD)
+ case SQFS_COMP_ZSTD:
+ ctxt->zstd_workspace = malloc(ZSTD_DCtxWorkspaceBound());
+ if (!ctxt->zstd_workspace)
+ return -ENOMEM;
+ break;
+#endif
default:
printf("Error: unknown compression type.\n");
return -EINVAL;
@@ -42,6 +53,11 @@
case SQFS_COMP_ZLIB:
break;
#endif
+#if IS_ENABLED(CONFIG_ZSTD)
+ case SQFS_COMP_ZSTD:
+ free(ctxt->zstd_workspace);
+ break;
+#endif
}
}
@@ -62,6 +78,22 @@
}
#endif
+#if IS_ENABLED(CONFIG_ZSTD)
+static int sqfs_zstd_decompress(struct squashfs_ctxt *ctxt, void *dest,
+ unsigned long dest_len, void *source, u32 src_len)
+{
+ ZSTD_DCtx *ctx;
+ size_t wsize;
+ int ret;
+
+ wsize = ZSTD_DCtxWorkspaceBound();
+ ctx = ZSTD_initDCtx(ctxt->zstd_workspace, wsize);
+ ret = ZSTD_decompressDCtx(ctx, dest, dest_len, source, src_len);
+
+ return ZSTD_isError(ret);
+}
+#endif /* CONFIG_ZSTD */
+
int sqfs_decompress(struct squashfs_ctxt *ctxt, void *dest,
unsigned long *dest_len, void *source, u32 src_len)
{
@@ -79,6 +111,16 @@
break;
#endif
+#if IS_ENABLED(CONFIG_ZSTD)
+ case SQFS_COMP_ZSTD:
+ ret = sqfs_zstd_decompress(ctxt, dest, *dest_len, source, src_len);
+ if (ret) {
+ printf("ZSTD Error code: %d\n", ZSTD_getErrorCode(ret));
+ return -EINVAL;
+ }
+
+ break;
+#endif
default:
printf("Error: unknown compression type.\n");
return -EINVAL;