Make it possible to compile mkfs.ubifs without zlib

This one is a bit trickier than adding WITH_ZLIB ifdefs. Some parts
of the code assume that zlib is always present and have complicated
fallback behavior. Particularly the "favor_lzo" compression method
that uses either zlib or lzo, whichever produces the better result.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

2 files changed, 32 insertions, 13 deletions

diff --git a/ubifs-utils/mkfs.ubifs/compr.c b/ubifs-utils/mkfs.ubifs/compr.c
index 07f6d4a..e4324f3 100644
--- a/ubifs-utils/mkfs.ubifs/compr.c
+++ b/ubifs-utils/mkfs.ubifs/compr.c
@@ -32,9 +32,11 @@
 #include <zstd.h>
 #endif
 
+#ifdef WITH_ZLIB
 #define crc32 __zlib_crc32
 #include <zlib.h>
 #undef crc32
+#endif
 
 #include "compr.h"
 #include "mkfs.ubifs.h"
@@ -45,6 +47,7 @@ static unsigned long long errcnt = 0;
 static struct ubifs_info *c = &info_;
 #endif
 
+#ifdef WITH_ZLIB
 #define DEFLATE_DEF_LEVEL     Z_DEFAULT_COMPRESSION
 #define DEFLATE_DEF_WINBITS   11
 #define DEFLATE_DEF_MEMLEVEL  8
@@ -91,6 +94,7 @@ static int zlib_deflate(void *in_buf, size_t in_len, void *out_buf,
 
 	return 0;
 }
+#endif
 
 #ifdef WITH_LZO
 static int lzo_compress(void *in_buf, size_t in_len, void *out_buf,
@@ -140,7 +144,7 @@ static int no_compress(void *in_buf, size_t in_len, void *out_buf,
 
 static char *zlib_buf;
 
-#ifdef WITH_LZO
+#if defined(WITH_LZO) && defined(WITH_ZLIB)
 static int favor_lzo_compress(void *in_buf, size_t in_len, void *out_buf,
 			       size_t *out_len, int *type)
 {
@@ -198,21 +202,24 @@ int compress_data(void *in_buf, size_t in_len, void *out_buf, size_t *out_len,
 		return MKFS_UBIFS_COMPR_NONE;
 	}
 
-#ifndef WITH_LZO
-	{
-		switch (type) {
-#else
+#if defined(WITH_LZO) && defined(WITH_ZLIB)
 	if (c->favor_lzo)
 		ret = favor_lzo_compress(in_buf, in_len, out_buf, out_len, &type);
 	else {
+#else
+	{
+#endif
 		switch (type) {
+#ifdef WITH_LZO
 		case MKFS_UBIFS_COMPR_LZO:
 			ret = lzo_compress(in_buf, in_len, out_buf, out_len);
 			break;
 #endif
+#ifdef WITH_ZLIB
 		case MKFS_UBIFS_COMPR_ZLIB:
 			ret = zlib_deflate(in_buf, in_len, out_buf, out_len);
 			break;
+#endif
 #ifdef WITH_ZSTD
 		case MKFS_UBIFS_COMPR_ZSTD:
 			ret = zstd_compress(in_buf, in_len, out_buf, out_len);
@@ -244,9 +251,13 @@ int init_compression(void)
 		return -1;
 #endif
 
+#ifndef WITH_ZLIB
+	zlib_buf = NULL;
+#else
 	zlib_buf = malloc(UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR);
 	if (!zlib_buf)
 		goto err;
+#endif
 
 #ifdef WITH_ZSTD
 	zctx = ZSTD_createCCtx();
diff --git a/ubifs-utils/mkfs.ubifs/mkfs.ubifs.c b/ubifs-utils/mkfs.ubifs/mkfs.ubifs.c
index 5d3b80c..42a47f8 100644
--- a/ubifs-utils/mkfs.ubifs/mkfs.ubifs.c
+++ b/ubifs-utils/mkfs.ubifs/mkfs.ubifs.c
@@ -539,10 +539,12 @@ static void select_default_compr(void)
 		return;
 	}
 
-#ifndef WITH_LZO
+#ifdef WITH_LZO
+	c->default_compr = UBIFS_COMPR_LZO;
+#elif defined(WITH_ZLIB)
 	c->default_compr = UBIFS_COMPR_ZLIB;
 #else
-	c->default_compr = UBIFS_COMPR_LZO;
+	c->default_compr = UBIFS_COMPR_NONE;
 #endif
 }
 
@@ -681,26 +683,30 @@ static int get_options(int argc, char**argv)
 		case 'x':
 			if (strcmp(optarg, "none") == 0)
 				c->default_compr = UBIFS_COMPR_NONE;
+#ifdef WITH_ZLIB
 			else if (strcmp(optarg, "zlib") == 0)
 				c->default_compr = UBIFS_COMPR_ZLIB;
+#endif
 #ifdef WITH_ZSTD
 			else if (strcmp(optarg, "zstd") == 0)
 				c->default_compr = UBIFS_COMPR_ZSTD;
 #endif
 #ifdef WITH_LZO
+			else if (strcmp(optarg, "lzo") == 0)
+				c->default_compr = UBIFS_COMPR_LZO;
+#endif
+#if defined(WITH_LZO) && defined(WITH_ZLIB)
 			else if (strcmp(optarg, "favor_lzo") == 0) {
 				c->default_compr = UBIFS_COMPR_LZO;
 				c->favor_lzo = 1;
-			} else if (strcmp(optarg, "lzo") == 0) {
-				c->default_compr = UBIFS_COMPR_LZO;
 			}
 #endif
 			else
 				return err_msg("bad compressor name");
 			break;
 		case 'X':
-#ifndef WITH_LZO
-			return err_msg("built without LZO support");
+#if !defined(WITH_LZO) && !defined(WITH_ZLIB)
+			return err_msg("built without LZO or ZLIB support");
 #else
 			c->favor_percent = strtol(optarg, &endp, 0);
 			if (*endp != '\0' || endp == optarg ||
@@ -1858,10 +1864,12 @@ static int add_file(const char *path_name, struct stat *st, ino_t inum,
 		out_len = NODE_BUFFER_SIZE - UBIFS_DATA_NODE_SZ;
 		if (c->default_compr == UBIFS_COMPR_NONE &&
 		    !c->encrypted && (flags & FS_COMPR_FL))
-#ifndef WITH_LZO
+#ifdef WITH_LZO
+			use_compr = UBIFS_COMPR_LZO;
+#elif defined(WITH_ZLIB)
 			use_compr = UBIFS_COMPR_ZLIB;
 #else
-			use_compr = UBIFS_COMPR_LZO;
+			use_compr = UBIFS_COMPR_NONE;
 #endif
 		else
 			use_compr = c->default_compr;