diff --git a/scst/include/scst.h b/scst/include/scst.h
index 6322aa5da..e5240b743 100644
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -4704,6 +4704,38 @@ static inline __be16 scst_cmd_get_dif_app_tag(struct scst_cmd *cmd,
 	return cmd->dev->dev_dif_static_app_tag;
 }
 
+#if defined(RHEL_MAJOR) && RHEL_MAJOR -0 <= 5
+static inline uint16_t get_unaligned_be16(const void *p)
+{
+	return be16_to_cpu(get_unaligned((__be16 *)p));
+}
+
+static inline void put_unaligned_be16(uint16_t i, void *p)
+{
+	put_unaligned(cpu_to_be16(i), (__be16 *)p);
+}
+
+static inline uint32_t get_unaligned_be32(const void *p)
+{
+	return be32_to_cpu(get_unaligned((__be32 *)p));
+}
+
+static inline void put_unaligned_be32(uint32_t i, void *p)
+{
+	put_unaligned(cpu_to_be32(i), (__be32 *)p);
+}
+
+static inline uint64_t get_unaligned_be64(const void *p)
+{
+	return be64_to_cpu(get_unaligned((__be64 *)p));
+}
+
+static inline void put_unaligned_be64(uint64_t i, void *p)
+{
+	put_unaligned(cpu_to_be64(i), (__be64 *)p);
+}
+#endif
+
 /*
  * Returns T10-PI type 2 expected initial reference tag as LBA, i.e. converted
  * into CPU endianness. Valid only with protection type 2.
@@ -5595,38 +5627,6 @@ if (!(condition)) {							\
 	finish_wait(&(wq), &__wait);					\
 }
 
-#if defined(RHEL_MAJOR) && RHEL_MAJOR -0 <= 5
-static inline uint16_t get_unaligned_be16(const void *p)
-{
-	return be16_to_cpu(get_unaligned((__be16 *)p));
-}
-
-static inline void put_unaligned_be16(uint16_t i, void *p)
-{
-	put_unaligned(cpu_to_be16(i), (__be16 *)p);
-}
-
-static inline uint32_t get_unaligned_be32(const void *p)
-{
-	return be32_to_cpu(get_unaligned((__be32 *)p));
-}
-
-static inline void put_unaligned_be32(uint32_t i, void *p)
-{
-	put_unaligned(cpu_to_be32(i), (__be32 *)p);
-}
-
-static inline uint64_t get_unaligned_be64(const void *p)
-{
-	return be64_to_cpu(get_unaligned((__be64 *)p));
-}
-
-static inline void put_unaligned_be64(uint64_t i, void *p)
-{
-	put_unaligned(cpu_to_be64(i), (__be64 *)p);
-}
-#endif
-
 /* Only use get_unaligned_be24() if reading p - 1 is allowed. */
 static inline uint32_t get_unaligned_be24(const uint8_t *const p)
 {
diff --git a/scst/include/scst_const.h b/scst/include/scst_const.h
index a2546d9b4..b695f1d4b 100644
--- a/scst/include/scst_const.h
+++ b/scst/include/scst_const.h
@@ -375,6 +375,9 @@ static inline int scst_sense_response_code(const uint8_t *sense)
 /* Upstream commit 93aae17a (v2.6.38) */
 #define GET_EVENT_STATUS_NOTIFICATION 0x4a
 #endif
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26)
+#define VARIABLE_LENGTH_CMD   0x7f
+#endif
 #ifndef READ_16
 #define READ_16               0x88
 #endif
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index fac548d7e..b944cd61c 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -33,7 +33,10 @@
 #include <asm/kmap_types.h>
 #include <asm/unaligned.h>
 #include <asm/checksum.h>
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
 #include <linux/crc-t10dif.h>
+#endif
 #include <linux/namei.h>
 #include <linux/mount.h>
 
@@ -7696,7 +7699,12 @@ EXPORT_SYMBOL(scst_put_buf_full);
 
 static __be16 scst_dif_crc_fn(const void *data, unsigned int len)
 {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
 	return cpu_to_be16(crc_t10dif(data, len));
+#else
+	WARN_ON_ONCE(true);
+	return 0;
+#endif
 }
 
 static __be16 scst_dif_ip_fn(const void *data, unsigned int len)