iscsitarget: resolve build error with linux kernel 4.8

The below changes in kernel source, triggered iscsitarget
build fail with linux kernel v4.8.

1. An extra 'flags' argument has been passed to vfs_readv/vfs_writev
   syscalls in v4.8. So, set this argument to "0" for now
   (as there is no real need for that).
   Ref: https://github.com/torvalds/linux/commit/793b80ef14af56d20c998265287648ad34239b6f
   Solves:
   -- snip --
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/nthread.c: In function 'write_data':
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/nthread.c:350:9: error: too few arguments to function 'vfs_writev'
   res = vfs_writev(file, (struct iovec __user *) iop, count, &off);
         ^~~~~~~~~~
   -- snip --

2. Redefine dropped PAGE_CACHE_* and page_cache_{get,release} definitions,
   as they have been dropped with v4.8
   Ref: https://github.com/torvalds/linux/commit/1fa64f198b9f8d6ec0f7aec7c18dc94684391140
   Solves:
   -- snip --
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/param.c: In function 'sess_param_check':
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/param.c:48:41: error: 'PAGE_CACHE_SIZE' undeclared (first use in this function)
       (u32) ((ISCSI_CONN_IOV_MAX - 1) * PAGE_CACHE_SIZE));
                                         ^
   -- snip --

3. Replace crypto_hash interfaces with crypto_ahash interfaces,
   Ref: https://github.com/torvalds/linux/commit/896545098777564212b9e91af4c973f094649aa7
   Ref: https://www.redhat.com/archives/dm-devel/2016-January/msg00244.html
   Solves:
   -- snip --
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c: In function 'digest_init':
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c:42:23: error: implicit declaration of function 'crypto_alloc_hash' [-Werror=implicit-function-declaration]
   conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
                       ^~~~~~~~~~~~~~~~~
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c: In function 'digest_cleanup':
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c:77:3: error: implicit declaration of function 'crypto_free_hash' [-Werror=implicit-function-declaration]
   crypto_free_hash(conn->tx_hash.tfm);
   ^~~~~~~~~~~~~~~~
   -- snip --

4. The earlier "rw" parameter has been set in "bi_rw" within
   bio structure, hence remove "rw" argument.
   Ref: https://github.com/torvalds/linux/commit/4e49ea4a3d276365bf7396c9b77b4d1d5923835a
   Solves:
-- snip --
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/block-io.c:140:14: warning: passing argument 1 of 'submit_bio' makes pointer from integer without a cast [-Wint-conversion]
   submit_bio(rw, bio);
              ^~
-- snip --

5. The 'len' argument from sk_data_ready() callback has been removed in
   linux kernel v4.3 and above.
   Ref: https://github.com/torvalds/linux/commit/676d23690fb62b5d51ba5d659935e9f7d9da9f8e
   Solves:
-- snip --
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/conn.c: In function 'iet_socket_bind':
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/conn.c:143:38: error: assignment from incompatible pointer type [-Werror=incompatible-pointer-types]
  target->nthread_info.old_data_ready = conn->sock->sk->sk_data_ready;
                                      ^
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/conn.c:144:32: error: assignment from incompatible pointer type [-Werror=incompatible-pointer-types]
  conn->sock->sk->sk_data_ready = iet_data_ready;
                                ^
-- snip --

6.
   A. The "size" argument has been dropped from sock_recvmsg syscall in v4.8,
      as all callers have it equal to msg_data_left(msg).
   B. 'struct user_msghdr' is being used for userland-side msghdr instead
      of 'struct msghdr', which is used for kernel-side msghdr in linux v3.19
      and above, so typecase it while calling sock_recvmsg syscall.
   Ref: https://github.com/torvalds/linux/commit/2da62906b1e298695e1bb725927041cd59942c98
        https://github.com/torvalds/linux/commit/666547ff591cebdedc4679bf6b1b3f3383a8dea3
   Solves:
   -- snip --
TOPDIR/tmp-glibc/work-shared/qemux86/kernel-source/include/linux/net.h:222:5: note: expected 'struct msghdr *' but argument is of type 'struct user_msghdr *'
 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
     ^~~~~~~~~~~~
TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/nthread.c:129:8: error: too many arguments to function 'sock_recvmsg'
  res = sock_recvmsg(conn->sock, &msg, len, MSG_DONTWAIT | MSG_NOSIGNAL);
        ^~~~~~~~~~~~
   -- snip --

Detailed error log is at: http://errors.yoctoproject.org/Errors/Details/83334/

Signed-off-by: Jagadeesh Krishnanjanappa <jkrishnanjanappa@mvista.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>

2 files changed, 527 insertions, 4 deletions

diff --git a/meta-networking/recipes-extended/iscsitarget/files/build_with_updated_interfaces_of_linux_v4.8_and_above.patch b/meta-networking/recipes-extended/iscsitarget/files/build_with_updated_interfaces_of_linux_v4.8_and_above.patch
new file mode 100644
index 0000000000..e55c407a41
--- /dev/null
+++ b/meta-networking/recipes-extended/iscsitarget/files/build_with_updated_interfaces_of_linux_v4.8_and_above.patch
@@ -0,0 +1,525 @@
+Resolve build error with linux kernel 4.8
+
+The below changes in kernel source, triggered iscsitarget
+build fail with linux kernel v4.8.
+
+1. An extra 'flags' argument has been passed to vfs_readv/vfs_writev
+   syscalls in v4.8. So, set this argument to "0" for now
+   (as there is no real need for that).
+   Ref: https://github.com/torvalds/linux/commit/793b80ef14af56d20c998265287648ad34239b6f
+   Solves:
+   -- snip --
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/nthread.c: In function 'write_data':
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/nthread.c:350:9: error: too few arguments to function 'vfs_writev'
+   res = vfs_writev(file, (struct iovec __user *) iop, count, &off);
+         ^~~~~~~~~~
+   -- snip --
+
+2. Redefine dropped PAGE_CACHE_* and page_cache_{get,release} definitions,
+   as they have been dropped with v4.8
+   Ref: https://github.com/torvalds/linux/commit/1fa64f198b9f8d6ec0f7aec7c18dc94684391140
+   Solves:
+   -- snip --
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/param.c: In function 'sess_param_check':
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/param.c:48:41: error: 'PAGE_CACHE_SIZE' undeclared (first use in this function)
+       (u32) ((ISCSI_CONN_IOV_MAX - 1) * PAGE_CACHE_SIZE));
+                                         ^
+   -- snip --
+
+3. Replace crypto_hash interfaces with crypto_ahash interfaces,
+   Ref: https://github.com/torvalds/linux/commit/896545098777564212b9e91af4c973f094649aa7
+   Ref: https://www.redhat.com/archives/dm-devel/2016-January/msg00244.html
+   Solves:
+   -- snip --
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c: In function 'digest_init':
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c:42:23: error: implicit declaration of function 'crypto_alloc_hash' [-Werror=implicit-function-declaration]
+   conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
+                       ^~~~~~~~~~~~~~~~~
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c: In function 'digest_cleanup':
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/digest.c:77:3: error: implicit declaration of function 'crypto_free_hash' [-Werror=implicit-function-declaration]
+   crypto_free_hash(conn->tx_hash.tfm);
+   ^~~~~~~~~~~~~~~~
+   -- snip --
+
+4. The earlier "rw" parameter has been set in "bi_rw" within
+   bio structure, hence remove "rw" argument.
+   Ref: https://github.com/torvalds/linux/commit/4e49ea4a3d276365bf7396c9b77b4d1d5923835a
+   Solves:
+-- snip --
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/block-io.c:140:14: warning: passing argument 1 of 'submit_bio' makes pointer from integer without a cast [-Wint-conversion]
+   submit_bio(rw, bio);
+              ^~
+-- snip --
+
+5. The 'len' argument from sk_data_ready() callback has been removed in
+   linux kernel v4.3 and above.
+   Ref: https://github.com/torvalds/linux/commit/676d23690fb62b5d51ba5d659935e9f7d9da9f8e
+   Solves:
+-- snip --
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/conn.c: In function 'iet_socket_bind':
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/conn.c:143:38: error: assignment from incompatible pointer type [-Werror=incompatible-pointer-types]
+  target->nthread_info.old_data_ready = conn->sock->sk->sk_data_ready;
+                                      ^
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/conn.c:144:32: error: assignment from incompatible pointer type [-Werror=incompatible-pointer-types]
+  conn->sock->sk->sk_data_ready = iet_data_ready;
+                                ^
+-- snip --
+
+6.
+   A. The "size" argument has been dropped from sock_recvmsg syscall in v4.8,
+      as all callers have it equal to msg_data_left(msg).
+   B. 'struct user_msghdr' is being used for userland-side msghdr instead
+      of 'struct msghdr', which is used for kernel-side msghdr in linux v3.19
+      and above, so typecase it while calling sock_recvmsg syscall.
+   Ref: https://github.com/torvalds/linux/commit/2da62906b1e298695e1bb725927041cd59942c98
+        https://github.com/torvalds/linux/commit/666547ff591cebdedc4679bf6b1b3f3383a8dea3
+   Solves:
+   -- snip --
+TOPDIR/tmp-glibc/work-shared/qemux86/kernel-source/include/linux/net.h:222:5: note: expected 'struct msghdr *' but argument is of type 'struct user_msghdr *'
+ int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
+     ^~~~~~~~~~~~
+TOPDIR/tmp-glibc/work/qemux86-oe-linux/iscsitarget/1.4.20.3+svn502-r0/iscsitarget-1.4.20.3+svn502/kernel/nthread.c:129:8: error: too many arguments to function 'sock_recvmsg'
+  res = sock_recvmsg(conn->sock, &msg, len, MSG_DONTWAIT | MSG_NOSIGNAL);
+        ^~~~~~~~~~~~
+   -- snip --
+
+Detailed error log is at: http://errors.yoctoproject.org/Errors/Details/83334/
+
+Upstream-Status: Pending
+
+Signed-off-by: Jagadeesh Krishnanjanappa <jkrishnanjanappa@mvista.com>
+
+diff -Naurp iscsitarget-1.4.20.3+svn502_org/kernel/block-io.c iscsitarget-1.4.20.3+svn502/kernel/block-io.c
+--- iscsitarget-1.4.20.3+svn502_org/kernel/block-io.c	2016-09-25 19:45:01.814641016 +0530
++++ iscsitarget-1.4.20.3+svn502/kernel/block-io.c	2016-09-25 19:47:59.666474094 +0530
+@@ -57,7 +57,6 @@ static int
+ blockio_make_request(struct iet_volume *volume, struct tio *tio, int rw)
+ {
+ 	struct blockio_data *bio_data = volume->private;
+-	struct request_queue *bdev_q = bdev_get_queue(bio_data->bdev);
+ 	struct tio_work *tio_work;
+ 	struct bio *tio_bio = NULL, *bio = NULL, *biotail = NULL;
+ 	struct blk_plug plug;
+@@ -69,6 +68,7 @@ blockio_make_request(struct iet_volume *
+ 	int err = 0;
+ 	loff_t ppos = tio->offset;	
+ #else	
++	struct request_queue *bdev_q = bdev_get_queue(bio_data->bdev);
+ 	int max_pages = 1;
+ 	int err = 0;
+ 
+@@ -102,7 +102,11 @@ blockio_make_request(struct iet_volume *
+ 		/* bi_sector is ALWAYS in units of 512 bytes */
+ 		bio->bi_iter.bi_sector = ppos >> 9;
+ 		bio->bi_bdev = bio_data->bdev;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++		bio->bi_end_io = (bio_end_io_t *) blockio_bio_endio;
++#else
+ 		bio->bi_end_io = blockio_bio_endio;
++#endif
+ 		bio->bi_private = tio_work;
+ 
+ 		if (tio_bio)
+@@ -137,7 +141,12 @@ blockio_make_request(struct iet_volume *
+ 		tio_bio = tio_bio->bi_next;
+ 		bio->bi_next = NULL;
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
++		submit_bio(bio);
++#else
+ 		submit_bio(rw, bio);
++#endif
+ 	}
+ 
+ 	blk_finish_plug(&plug);
+diff -Naurp iscsitarget-1.4.20.3+svn502_org/kernel/conn.c iscsitarget-1.4.20.3+svn502/kernel/conn.c
+--- iscsitarget-1.4.20.3+svn502_org/kernel/conn.c	2016-09-25 19:45:01.774641057 +0530
++++ iscsitarget-1.4.20.3+svn502/kernel/conn.c	2016-09-25 19:47:59.666474094 +0530
+@@ -89,13 +89,21 @@ static void iet_state_change(struct sock
+ 	target->nthread_info.old_state_change(sk);
+ }
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
++static void iet_data_ready(struct sock *sk)
++#else
+ static void iet_data_ready(struct sock *sk, int len)
++#endif    
+ {
+ 	struct iscsi_conn *conn = sk->sk_user_data;
+ 	struct iscsi_target *target = conn->session->target;
+ 
+ 	nthread_wakeup(target);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
++	target->nthread_info.old_data_ready(sk);
++#else
+ 	target->nthread_info.old_data_ready(sk, len);
++#endif
+ }
+ 
+ /*
+@@ -140,8 +148,14 @@ static void iet_socket_bind(struct iscsi
+ 	target->nthread_info.old_state_change = conn->sock->sk->sk_state_change;
+ 	conn->sock->sk->sk_state_change = iet_state_change;
+ 
++#if 0//LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	target->nthread_info.old_data_ready = (void (*) (struct sock *, int )) \
++						conn->sock->sk->sk_data_ready;
++	conn->sock->sk->sk_data_ready = (void (*) (struct sock *)) iet_data_ready;
++#else
+ 	target->nthread_info.old_data_ready = conn->sock->sk->sk_data_ready;
+ 	conn->sock->sk->sk_data_ready = iet_data_ready;
++#endif
+ 
+ 	target->nthread_info.old_write_space = conn->sock->sk->sk_write_space;
+ 	conn->sock->sk->sk_write_space = iet_write_space;
+diff -Naurp iscsitarget-1.4.20.3+svn502_org/kernel/digest.c iscsitarget-1.4.20.3+svn502/kernel/digest.c
+--- iscsitarget-1.4.20.3+svn502_org/kernel/digest.c	2014-05-07 02:29:55.000000000 +0530
++++ iscsitarget-1.4.20.3+svn502/kernel/digest.c	2016-09-25 19:47:59.666474094 +0530
+@@ -30,6 +30,9 @@ void digest_alg_available(unsigned int *
+ int digest_init(struct iscsi_conn *conn)
+ {
+ 	int err = 0;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	struct crypto_ahash *tfm;
++#endif
+ 
+ 	if (!(conn->hdigest_type & DIGEST_ALL))
+ 		conn->hdigest_type = DIGEST_NONE;
+@@ -39,15 +42,40 @@ int digest_init(struct iscsi_conn *conn)
+ 
+ 	if (conn->hdigest_type & DIGEST_CRC32C ||
+ 	    conn->ddigest_type & DIGEST_CRC32C) {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++		tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
++		if (IS_ERR(tfm)) {
++			tfm = NULL;
++#else
+ 		conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
+ 						      CRYPTO_ALG_ASYNC);
+ 		conn->rx_hash.flags = 0;
+ 		if (IS_ERR(conn->rx_hash.tfm)) {
+ 			conn->rx_hash.tfm = NULL;
++#endif
+ 			err = -ENOMEM;
+ 			goto out;
+ 		}
+-
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++		conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
++		if (!conn->rx_hash) {
++			pr_err("ahash_request_alloc() failed for conn->rx_hash\n");
++			crypto_free_ahash(tfm);
++			err = -ENOMEM;
++			goto out;
++		}
++		ahash_request_set_callback(conn->rx_hash, 0, NULL, NULL);
++		conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
++		if(!conn->tx_hash) {
++			pr_err("ahash_request_alloc() failed for conn->tx_hash\n");
++			ahash_request_free(conn->rx_hash);
++			conn->rx_hash = NULL;
++			crypto_free_ahash(tfm);
++			err = -ENOMEM;
++			goto out;
++		}
++		ahash_request_set_callback(conn->tx_hash, 0, NULL, NULL);
++#else
+ 		conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
+ 						      CRYPTO_ALG_ASYNC);
+ 		conn->tx_hash.flags = 0;
+@@ -56,6 +84,7 @@ int digest_init(struct iscsi_conn *conn)
+ 			err = -ENOMEM;
+ 			goto out;
+ 		}
++#endif
+ 	}
+ 
+ out:
+@@ -73,10 +102,21 @@ out:
+  */
+ void digest_cleanup(struct iscsi_conn *conn)
+ {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	ahash_request_free(conn->tx_hash);
++	if (conn->rx_hash) {
++		struct crypto_ahash *tfm;
++		tfm = crypto_ahash_reqtfm(conn->rx_hash);
++		ahash_request_free(conn->rx_hash);
++		crypto_free_ahash(tfm);
++	}
++
++#else
+ 	if (conn->tx_hash.tfm)
+ 		crypto_free_hash(conn->tx_hash.tfm);
+ 	if (conn->rx_hash.tfm)
+ 		crypto_free_hash(conn->rx_hash.tfm);
++#endif
+ }
+ 
+ /**
+@@ -160,8 +200,13 @@ static inline void __dbg_simulate_data_d
+ 	}
+ }
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++static void digest_header(struct ahash_request *hash, struct iscsi_pdu *pdu,
++			  u8 *crc)
++#else
+ static void digest_header(struct hash_desc *hash, struct iscsi_pdu *pdu,
+ 			  u8 *crc)
++#endif
+ {
+ 	struct scatterlist sg[2];
+ 	unsigned int nbytes = sizeof(struct iscsi_hdr);
+@@ -174,16 +219,27 @@ static void digest_header(struct hash_de
+ 		nbytes += pdu->ahssize;
+ 	}
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	crypto_ahash_init(hash);
++	ahash_request_set_crypt(hash, sg, crc, nbytes);
++	crypto_ahash_update(hash);
++	crypto_ahash_digest(hash);
++#else
+ 	crypto_hash_init(hash);
+ 	crypto_hash_update(hash, sg, nbytes);
+ 	crypto_hash_final(hash, crc);
++#endif
+ }
+ 
+ int digest_rx_header(struct iscsi_cmnd *cmnd)
+ {
+ 	u32 crc;
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	digest_header(cmnd->conn->rx_hash, &cmnd->pdu, (u8 *) &crc);
++#else
+ 	digest_header(&cmnd->conn->rx_hash, &cmnd->pdu, (u8 *) &crc);
++#endif
+ 	if (crc != cmnd->hdigest)
+ 		return -EIO;
+ 
+@@ -192,11 +248,20 @@ int digest_rx_header(struct iscsi_cmnd *
+ 
+ void digest_tx_header(struct iscsi_cmnd *cmnd)
+ {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	digest_header(cmnd->conn->tx_hash, &cmnd->pdu, (u8 *) &cmnd->hdigest);
++#else
+ 	digest_header(&cmnd->conn->tx_hash, &cmnd->pdu, (u8 *) &cmnd->hdigest);
++#endif
+ }
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++static void digest_data(struct ahash_request *hash, struct iscsi_cmnd *cmnd,
++			struct tio *tio, u32 offset, u8 *crc)
++#else
+ static void digest_data(struct hash_desc *hash, struct iscsi_cmnd *cmnd,
+ 			struct tio *tio, u32 offset, u8 *crc)
++#endif
+ {
+ 	struct scatterlist *sg = cmnd->conn->hash_sg;
+ 	u32 size, length, npages;
+@@ -214,7 +279,11 @@ static void digest_data(struct hash_desc
+ 	BUG_ON(npages > ISCSI_CONN_IOV_MAX);
+ 
+ 	sg_init_table(sg, ARRAY_SIZE(cmnd->conn->hash_sg));
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	crypto_ahash_init(hash);
++#else
+ 	crypto_hash_init(hash);
++#endif
+ 
+ 	for (i = 0; size > 0; i++) {
+ 		length = min_t(u32, PAGE_CACHE_SIZE - offset, size);
+@@ -225,8 +294,14 @@ static void digest_data(struct hash_desc
+ 
+ 	sg_mark_end(&sg[i - 1]);
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	ahash_request_set_crypt(hash, sg, crc, nbytes);
++	crypto_ahash_update(hash);
++	crypto_ahash_digest(hash);
++#else
+ 	crypto_hash_update(hash, sg, nbytes);
+ 	crypto_hash_final(hash, crc);
++#endif
+ }
+ 
+ int digest_rx_data(struct iscsi_cmnd *cmnd)
+@@ -251,8 +326,11 @@ int digest_rx_data(struct iscsi_cmnd *cm
+ 		tio = cmnd->tio;
+ 		offset = 0;
+ 	}
+-
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	digest_data(cmnd->conn->rx_hash, cmnd, tio, offset, (u8 *) &crc);
++#else
+ 	digest_data(&cmnd->conn->rx_hash, cmnd, tio, offset, (u8 *) &crc);
++#endif
+ 
+ 	if (!cmnd->conn->read_overflow &&
+ 	    (cmnd_opcode(cmnd) != ISCSI_OP_PDU_REJECT)) {
+@@ -269,6 +347,11 @@ void digest_tx_data(struct iscsi_cmnd *c
+ 	struct iscsi_data_out_hdr *req = (struct iscsi_data_out_hdr *)&cmnd->pdu.bhs;
+ 
+ 	assert(tio);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	digest_data(cmnd->conn->tx_hash, cmnd, tio,
++		    be32_to_cpu(req->buffer_offset), (u8 *) &cmnd->ddigest);
++#else
+ 	digest_data(&cmnd->conn->tx_hash, cmnd, tio,
+ 		    be32_to_cpu(req->buffer_offset), (u8 *) &cmnd->ddigest);
++#endif
+ }
+diff -Naurp iscsitarget-1.4.20.3+svn502_org/kernel/iscsi.h iscsitarget-1.4.20.3+svn502/kernel/iscsi.h
+--- iscsitarget-1.4.20.3+svn502_org/kernel/iscsi.h	2016-09-25 19:45:01.734641099 +0530
++++ iscsitarget-1.4.20.3+svn502/kernel/iscsi.h	2016-09-25 19:47:59.666474094 +0530
+@@ -14,6 +14,7 @@
+ #include <linux/pagemap.h>
+ #include <linux/seq_file.h>
+ #include <linux/mm.h>
++#include <crypto/hash.h>
+ #include <linux/crypto.h>
+ #include <linux/scatterlist.h>
+ #include <net/sock.h>
+@@ -81,7 +82,11 @@ struct network_thread_info {
+ 	spinlock_t nthread_lock;
+ 
+ 	void (*old_state_change)(struct sock *);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
++	void (*old_data_ready)(struct sock *);
++#else
+ 	void (*old_data_ready)(struct sock *, int);
++#endif
+ 	void (*old_write_space)(struct sock *);
+ };
+ 
+@@ -275,8 +280,13 @@ struct iscsi_conn {
+ 	u32 write_offset;
+ 	int write_state;
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	struct ahash_request *rx_hash;
++	struct ahash_request *tx_hash;
++#else
+ 	struct hash_desc rx_hash;
+ 	struct hash_desc tx_hash;
++#endif
+ 	struct scatterlist hash_sg[ISCSI_CONN_IOV_MAX];
+ };
+ 
+@@ -552,4 +562,10 @@ enum cmnd_flags {
+ #define PRODUCT_ID	"VIRTUAL-DISK"
+ #define PRODUCT_REV	"0"
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++#define PAGE_CACHE_SHIFT	PAGE_SHIFT
++#define PAGE_CACHE_SIZE	PAGE_SIZE
++#define PAGE_CACHE_MASK	PAGE_MASK
++#endif
++
+ #endif	/* __ISCSI_H__ */
+diff -Naurp iscsitarget-1.4.20.3+svn502_org/kernel/nthread.c iscsitarget-1.4.20.3+svn502/kernel/nthread.c
+--- iscsitarget-1.4.20.3+svn502_org/kernel/nthread.c	2016-09-25 19:45:01.734641099 +0530
++++ iscsitarget-1.4.20.3+svn502/kernel/nthread.c	2016-09-25 19:47:59.666474094 +0530
+@@ -126,7 +126,12 @@ static int do_recv(struct iscsi_conn *co
+ 
+ 	oldfs = get_fs();
+ 	set_fs(get_ds());
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	res = sock_recvmsg(conn->sock, (struct msghdr *) &msg, \
++				MSG_DONTWAIT | MSG_NOSIGNAL);
++#else
+ 	res = sock_recvmsg(conn->sock, &msg, len, MSG_DONTWAIT | MSG_NOSIGNAL);
++#endif
+ 	set_fs(oldfs);
+ 
+ 	if (res <= 0) {
+@@ -347,7 +352,11 @@ static int write_data(struct iscsi_conn
+ 			;
+ 		oldfs = get_fs();
+ 		set_fs(KERNEL_DS);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++		res = vfs_writev(file, (struct iovec __user *) iop, count, &off, 0);
++#else
+ 		res = vfs_writev(file, (struct iovec __user *) iop, count, &off);
++#endif
+ 		set_fs(oldfs);
+ 		dprintk(D_DATA, "%#Lx:%u: %d(%ld)\n",
+ 			(unsigned long long) conn->session->sid, conn->cid,
+@@ -478,7 +487,11 @@ static int tx_ddigest(struct iscsi_cmnd
+ 	iov.iov_base = (char *) (&cmnd->ddigest) + (sizeof(u32) - rest);
+ 	iov.iov_len = rest;
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	res = kernel_sendmsg(cmnd->conn->sock, (struct msghdr *) &msg, &iov, 1, rest);
++#else
+ 	res = kernel_sendmsg(cmnd->conn->sock, &msg, &iov, 1, rest);
++#endif
+ 
+ 	if (res > 0) {
+ 		cmnd->conn->write_size -= res;
+@@ -677,7 +690,12 @@ static void close_conn(struct iscsi_conn
+ 
+ 	write_lock_bh(&conn->sock->sk->sk_callback_lock);
+ 	conn->sock->sk->sk_state_change = target->nthread_info.old_state_change;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	conn->sock->sk->sk_data_ready = (void (*) (struct sock *)) \
++					target->nthread_info.old_data_ready;
++#else
+ 	conn->sock->sk->sk_data_ready = target->nthread_info.old_data_ready;
++#endif
+ 	conn->sock->sk->sk_write_space = target->nthread_info.old_write_space;
+ 	write_unlock_bh(&conn->sock->sk->sk_callback_lock);
+ 
+diff -Naurp iscsitarget-1.4.20.3+svn502_org/kernel/volume.c iscsitarget-1.4.20.3+svn502/kernel/volume.c
+--- iscsitarget-1.4.20.3+svn502_org/kernel/volume.c	2016-09-25 19:45:01.734641099 +0530
++++ iscsitarget-1.4.20.3+svn502/kernel/volume.c	2016-09-25 19:47:59.666474094 +0530
+@@ -84,12 +84,25 @@ static int set_scsisn(struct iet_volume
+ /* Generate a MD5 hash of the target IQN and LUN number */
+ static void gen_scsiid(struct iet_volume *volume)
+ {
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	struct ahash_request *hash;
++	struct crypto_ahash *tfm;
++#else
+ 	struct hash_desc hash;
++#endif
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	tfm = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
++#else
+ 	hash.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+ 	hash.flags = 0;
++#endif
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++	if (!IS_ERR(tfm)) {
++#else
+ 	if (!IS_ERR(hash.tfm)) {
++#endif
+ 		struct scatterlist sg[2];
+ 		unsigned int nbytes = 0;
+ 
+@@ -102,11 +115,19 @@ static void gen_scsiid(struct iet_volume
+ 		sg_set_buf(&sg[1], &volume->lun, sizeof(volume->lun));
+ 		nbytes += sizeof(volume->lun);
+ 
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
++		crypto_ahash_init(hash);
++		ahash_request_set_crypt(hash, sg, volume->scsi_id, nbytes);
++		crypto_ahash_update(hash);
++		crypto_ahash_digest(hash);
++		crypto_free_ahash(tfm);
++#else
+ 		crypto_hash_init(&hash);
+ 		crypto_hash_update(&hash, sg, nbytes);
+ 		crypto_hash_final(&hash, volume->scsi_id);
+ 
+ 		crypto_free_hash(hash.tfm);
++#endif
+ 	} else {
+ 		/* If no MD5 available set ID to TID and LUN */
+ 		memcpy(volume->scsi_id, &volume->target->tid,
diff --git a/meta-networking/recipes-extended/iscsitarget/iscsitarget_1.4.20.3+svn502.bb b/meta-networking/recipes-extended/iscsitarget/iscsitarget_1.4.20.3+svn502.bb
index 4b5622b6e8..7279bc6378 100644
--- a/meta-networking/recipes-extended/iscsitarget/iscsitarget_1.4.20.3+svn502.bb
+++ b/meta-networking/recipes-extended/iscsitarget/iscsitarget_1.4.20.3+svn502.bb
@@ -12,7 +12,8 @@ SRC_URI = "http://ftp.heanet.ie/mirrors/ubuntu/pool/universe/i/${BPN}/${BPN}_${P
            file://use-kernel-makefile-to-get-kernel-version.patch \
            file://fix-errors-observed-with-linux-3.19-and-greater.patch \
            file://access-sk_v6_daddr-iff-IPV6-defined.patch \
-           file://build_with_updated_bio_struct_of_linux_v4.3_and_above.patch"
+           file://build_with_updated_bio_struct_of_linux_v4.3_and_above.patch \
+           file://build_with_updated_interfaces_of_linux_v4.8_and_above.patch"
 
 SRC_URI[md5sum] = "ef9bc823bbabd3c772208c00d5f2d089"
 SRC_URI[sha256sum] = "d3196ccb78a43266dce28587bfe30d8ab4db7566d7bce96057dfbb84100babb5"
@@ -56,6 +57,3 @@ FILES_${PN} += "${sbindir} \
 
 RDEPENDS_${PN} = "kernel-module-iscsi-trgt"
 RRECOMMENDS_${PN} = "kernel-module-crc32c kernel-module-libcrc32c"
-
-# http://errors.yoctoproject.org/Errors/Details/83334/
-PNBLACKLIST[iscsitarget] ?= "BROKEN: not compatible with default kernel version 4.8"