iSCSI Integration (shareiscsi)

This is iSCSI sharing for ZoL (shareiscsi).
* Supports the following iSCSI implementations (in this order of discovery):
  + IET         http://iscsitarget.sourceforge.net
  + STGT        http://stgt.berlios.de
  + SCST        http://scst.sourceforge.net
    + Requires that SCST was compiled with /sys support (the default).
  + LIO         http://linux-iscsi.org
* Will refuse to unshares an active target (one with sessions).
* Supports the following options to the 'shareiscsi' property:
  + name/iqn    Full iSCSI Qualified Name (IQN), including identifier.
                This is generated by iscsi_generate_target():
                + Uses the content of an optional /etc/iscsi_target_id file:
                  Example: iqn.YYYY-MM.tld.domain
                + If this file doesn't exist, it uses the current year, month
                  and domain name to generate the iqn.
                + The dataset name is appended at the end of the iqn, with
                  slashes replaced with dots.
                  => <iqn>:<dataset>
  + lun         LUN (0-16384)
                Default: 0 (1 for STGT)
  + type        Share mode (fileio, blockio, nullio, disk, tape)
                STGT: ssc, pt
                Default: blockio (disk for STGT)
  + iomode      IO mode (wb, wt, ro)
                STGT: rdwr, aio, mmap, sg, ssc
                Default: wt (rdwr for STGT)
  + blocksize   Logical block size (512, 1024, 2048, 4096)
                Default: Volume blocksize, 4096 if not usable.
                NOTE: Currently not supported for STGT (doesn't seem to be
                      an option for it in tgtadm).
  + initiator   Allow only this initiator to bind to target.
                Currently only availible for LIO, STGT and SCST.
  + authname    Global user to use in binds on targets.
  + authpass    Password for global user.
* If not called with a 'name/iqn' value, then force setting it.
  This so that the IQN doesn't change every month (when it is
  regenerated again). It will be generated by iscsi_generate_target()
  (see above).

NOTE:
+ Moved nfs.c:foreach_nfs_shareopt() to libshare.c:foreach_shareopt()
  so that it can be (re)used in smb.c and iscsi.c.
+ Split iSCSI implementation into their own separate source files
+ Use the list_{create,insert}() etc for keeping tabs of the linked lists
  instead of using a home-made version.
+ A half second delay had to be added in lib/libzfs/libzfs_mount.c:zfs_unmount()
  after the successful unshare. This to avoid 'dataset busy' when destroying
  recursivly.
= The 'initiator', 'authname' and 'authpass' option might have some issues:
  It will make the compatibility between the different iSCSI implementations
  questionable - can't switch between them easily (it will ONLY be availible
  in ZoL). I COULD make the option be silently ignored (instead of forcibly
  rejected if not availible).

  But that still doesn't solve the (possible) problem between ZoL and
  OpenZFS/Illumos (setting the option, will possibly introduce problems when
  importing the pool on something else than ZoL).

  So some more discussion might be needed..

include/libzfs.h

@@ -142,6 +142,8 @@ typedef enum zfs_error {
 	EZFS_DIFF,		/* general failure of zfs diff */
 	EZFS_DIFFDATA,		/* bad zfs diff data */
 	EZFS_POOLREADONLY,	/* pool is in read-only mode */
+	EZFS_UNSHAREISCSIFAILED, /* failed to unshare over iSCSI */
+	EZFS_SHAREISCSIFAILED,	/* failed to share over iSCSI */
 	EZFS_UNKNOWN
 } zfs_error_t;
 
@@ -566,6 +568,7 @@ typedef struct get_all_cb {
 	zfs_handle_t	**cb_handles;
 	size_t		cb_alloc;
 	size_t		cb_used;
+	uint_t		cb_types;
 	boolean_t	cb_verbose;
 	int		(*cb_getone)(zfs_handle_t *, void *);
 } get_all_cb_t;
@@ -721,13 +724,17 @@ extern int zfs_unshare(zfs_handle_t *);
  */
 extern boolean_t zfs_is_shared_nfs(zfs_handle_t *, char **);
 extern boolean_t zfs_is_shared_smb(zfs_handle_t *, char **);
+extern boolean_t zfs_is_shared_iscsi(zfs_handle_t *, char **);
 extern int zfs_share_nfs(zfs_handle_t *);
 extern int zfs_share_smb(zfs_handle_t *);
+extern int zfs_share_iscsi(zfs_handle_t *);
 extern int zfs_shareall(zfs_handle_t *);
 extern int zfs_unshare_nfs(zfs_handle_t *, const char *);
 extern int zfs_unshare_smb(zfs_handle_t *, const char *);
+extern int zfs_unshare_iscsi(zfs_handle_t *, const char *);
 extern int zfs_unshareall_nfs(zfs_handle_t *);
 extern int zfs_unshareall_smb(zfs_handle_t *);
+extern int zfs_unshareall_iscsi(zfs_handle_t *);
 extern int zfs_unshareall_bypath(zfs_handle_t *, const char *);
 extern int zfs_unshareall(zfs_handle_t *);
 extern int zfs_deleg_share_nfs(libzfs_handle_t *, char *, char *, char *,

include/libzfs_impl.h

@@ -123,7 +123,8 @@ struct zpool_handle {
 typedef enum {
 	PROTO_NFS = 0,
 	PROTO_SMB = 1,
-	PROTO_END = 2
+	PROTO_ISCSI = 2,
+	PROTO_END = 3
 } zfs_share_proto_t;
 
 /*
@@ -133,7 +134,8 @@ typedef enum {
 typedef enum {
 	SHARED_NOT_SHARED = 0x0,
 	SHARED_NFS = 0x2,
-	SHARED_SMB = 0x4
+	SHARED_SMB = 0x4,
+	SHARED_ISCSI = 0x8
 } zfs_share_type_t;
 
 int zfs_error(libzfs_handle_t *, int, const char *);

include/sys/fs/zfs.h

@@ -151,6 +151,7 @@ typedef enum {
 	ZFS_PROP_RELATIME,
 	ZFS_PROP_REDUNDANT_METADATA,
 	ZFS_PROP_OVERLAY,
+	ZFS_PROP_SHAREISCSI,
 	ZFS_NUM_PROPS
 } zfs_prop_t;
 
@@ -326,7 +327,9 @@ typedef enum zfs_share_op {
 	ZFS_SHARE_NFS = 0,
 	ZFS_UNSHARE_NFS = 1,
 	ZFS_SHARE_SMB = 2,
-	ZFS_UNSHARE_SMB = 3
+	ZFS_UNSHARE_SMB = 3,
+	ZFS_SHARE_ISCSI = 4,
+	ZFS_UNSHARE_ISCSI = 5
 } zfs_share_op_t;
 
 typedef enum zfs_smb_acl_op {

lib/libshare/Makefile.am

@@ -12,4 +12,13 @@ libshare_la_SOURCES = \
 	$(top_srcdir)/lib/libshare/nfs.c \
 	$(top_srcdir)/lib/libshare/nfs.h \
 	$(top_srcdir)/lib/libshare/smb.c \
-	$(top_srcdir)/lib/libshare/smb.h
+	$(top_srcdir)/lib/libshare/smb.h \
+	$(top_srcdir)/lib/libshare/iscsi.c \
+	$(top_srcdir)/lib/libshare/iscsi_iet.c \
+	$(top_srcdir)/lib/libshare/iscsi_lio.c \
+	$(top_srcdir)/lib/libshare/iscsi_scst.c \
+	$(top_srcdir)/lib/libshare/iscsi_stgt.c \
+	$(top_srcdir)/lib/libshare/iscsi.h
+
+libshare_la_LIBADD = \
+	$(top_builddir)/lib/libspl/libspl.la

lib/libshare/README_iscsi.txt

@@ -0,0 +1,124 @@
+This is iSCSI support for the IET, SCST and STGT iSCSI target implementations.
+
+     Implementation	URL					Package name(s)
+     IET		http://iscsitarget.sourceforge.net	iscsitarget + iscsitarget-dkms
+     SCST		http://scst.sourceforge.net		iscsi-scst + scst-dkms + scst-fileio-tgt + scstadmin
+     STGT		http://stgt.berlios.de			tgt
+     LIO		http://linux-iscsi.org			lio-utils + targetcli
+
+It will call ietmadm (for IET), tgtadm (for STGT) or modify files in
+/sys/kernel/scst_tgt (for SCST) or /sys/kernel/config/target (for LIO) to both
+add or remove a iSCSI target from the call to 'zfs share':
+
+  zfs create -s -V10G mypool/test
+  zfs set shareiscsi=on mypool/test
+
+There is no need to issue 'zfs share tank/test', because ZFS will
+automatically issue the corresponding share command(s) when setting
+(or modifying) the shareiscsi property.
+
+
+The driver will execute the following commands to setup a target (example!):
+
+* For IET:
+
+  /usr/sbin/ietadm --op new --tid TID --params Name=iqn.2010-09.org.zfsonlinux:mypool.test
+  /usr/sbin/ietadm --op new --tid TID --lun LUN --params Path=/dev/zvol/mypool/test,Type=fileio
+
+* For STGT:
+
+  tgtadm --lld iscsi --op new  --mode target      --tid TID -T iqn.2010-09.org.zfsonlinux:share.test
+  tgtadm --lld iscsi --op new  --mode logicalunit --tid TID --lun 1 -b /dev/zvol/mypool/test
+  tgtadm --lld iscsi --op bind --mode target      --tid TID --initiator-address ALL
+
+* For SCST:
+
+  SYSFS_SCST="/sys/kernel/scst_tgt"
+
+  echo "add_target iqn.2010-09.org.zfsonlinux:mypool.test" > $SYSFS_SCST/targets/iscsi/mgmt
+  echo "add_device DEVICE filename=/dev/zvol/mypool/test; blocksize=BLOCKSIZE" > $SYSFS_SCST/handlers/vdisk_blockio/mgmt
+  echo "add DEVICE LUN" > $SYSFS_SCST/targets/iscsi/iqn.2010-09.org.zfsonlinux:mypool.test/luns/mgmt
+  echo 1 > $SYSFS_SCST/targets/iscsi/iqn.2010-09.org.zfsonlinux:mypool.test/enabled
+
+* For LIO
+
+  SYSFS_LIO="/sys/kernel/config/target"
+
+  # TEST DATA:
+  ip=$(ifconfig | grep 'inet addr:' | grep -v '127.0.0.1' | head -n1 | sed "s@.*addr:\(.*\)  Bcast.*@\1@")
+  md5=$(date | md5sum | cut -f1 -d' ')
+
+  # SETUP Device
+  mkdir -p $SYSFS_LIO/core/iblock_TID/mypool.test
+  echo -n "/dev/zvol/mypool/test" > $SYSFS_LIO/core/iblock_TID/mypool.test/udev_path
+  echo -n "udev_path=/dev/zvol/mypool/test" > $SYSFS_LIO/core/iblock_TID/mypool.test/control
+  echo -n $md5 > $SYSFS_LIO/core/iblock_TID/mypool.test/wwn/vpd_unit_serial
+  echo 1 > $SYSFS_LIO/core/iblock_TID/mypool.test/enable
+  echo 4096 > $SYSFS_LIO/core/iblock_TID/mypool.test/attrib/block_size
+  echo 0 > $SYSFS_LIO/core/iblock_TID/mypool.test/attrib/emulate_tas
+  echo 0 > $SYSFS_LIO/core/iblock_TID/mypool.test/attrib/emulate_ua_intlck_ctrl
+
+  # SETUP IQN/Target
+  mkdir -p $SYSFS_LIO/iscsi/iqn.2010-09.org.zfsonlinux:mypool.test/tpgt_TID/np/$ip:3260
+  mkdir -p $SYSFS_LIO/iscsi/iqn.2010-09.org.zfsonlinux:mypool.test/tpgt_TID/lun/lun_LUN
+  ln -s $SYSFS_LIO/core/iblock_TID/mypool.test \
+     $SYSFS_LIO/iscsi/iqn.2010-09.org.zfsonlinux:mypool.test/tpgt_TID/lun/lun_LUN/$md5
+  echo -n 0 > $SYSFS_LIO/iscsi/discovery_auth/enforce_discovery_auth
+  echo 0 > $SYSFS_LIO/iscsi/iqn.2010-09.org.zfsonlinux:mypool.test/tpgt_TID/attrib/authentication
+  echo 1 > $SYSFS_LIO/iscsi/iqn.2010-09.org.zfsonlinux:mypool.test/tpgt_TID/enable
+
+Here the value DEVICE is generated by iscsi.c:iscsi_generate_scst_device_name()
+and is a randomized value, based on the exact time of day when
+called. This because SCST have a limit of 16 characters for the device
+name, and the chances of have duplicates is large. The BLOCKSIZE that
+is used depends on what blocksize the ZVOL was created with.
+
+The LUN value is by default 0 (1 for STGT becase LUN0 is the controller),
+but can be overridden using the 'lun' option to the 'shareiscsi' property.
+
+It (the driver) will automatically calculate the TID and IQN and use
+only the ZVOL (in this case 'share/test') in the command lines.
+
+If autogenerating the IQN is not wanted (because each reboot or unshare/share,
+if it's done in another month, will generate a new IQN), a hardcoded default
+can be set in /etc/iscsi_target_id like so:
+
+  echo iqn.2010-09.org.zfsonlinux > /etc/iscsi_target_id
+
+Then all targets will start with this value, only adding a colon
+and the ZVOL/dataset name (slashes replaced with dots):
+
+  iqn.2010-09.org.zfsonlinux:mypool.test
+
+
+In addition to executing ietadm, tgtadm or modifying files below
+/sys/kernel/scst_tgt or /sys/kernel/config/target, zfs will execute
+the following script (if it exist and is executable)
+'/sbin/zfs_share_iscsi.sh', like so:
+
+  /sbin/zfs_share_iscsi TID
+
+This is so that one can create custom commands to be done on the
+share.
+
+The only parameter to this script/executable is the TID and the
+driver will 'execute and forget'. Meaning, it will not care about
+exit code nor any output it gives.
+
+Example scripts have been provided, on for each of the iSCSI
+implementation supported:
+
+    zfs_share_iscsi.iet
+    zfs_share_iscsi.lio
+    zfs_share_iscsi.scst
+    zfs_share_iscsi.stgt
+
+Simply copy the one for your iSCSI implementation to /sbin/zfs_share/iscsi
+and then modify it to your requirenments.
+
+PS. The domainname needs to be set (in /proc/sys/kernel/domainname
+    using either 'sysctl', 'echo' or the command 'domainname') for
+    the driver to be able to work out the iqn correctly.
+
+    NOTE: This is only required if the IQN haven't been set in the
+    	  /etc/iscsi_target_id file!

lib/libshare/destroy_lio.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+# This is a script to simply unshare all LIO targets, without going through
+# ZFS. Mostly used for testing...
+
+SYSFS=/sys/kernel/config/target
+
+cd $SYSFS/iscsi/
+if [ -z "$*" ]; then
+    targets=`echo iqn.*`
+else
+    targets=`echo $*`
+fi
+
+for name in $targets; do
+    tid=`echo $SYSFS/core/iblock_*/$name | sed "s@.*iblock_\(.*\)/.*@\1@"`
+    lnk=`find $SYSFS/iscsi/$name/tpgt_$tid/lun/lun_*/* | egrep -v 'alua|statistics' | sed 's@.*/@@'`
+
+    echo 0 > $SYSFS/iscsi/$name/tpgt_$tid/enable
+
+    rmdir $SYSFS/iscsi/$name/tpgt_$tid/np/*
+    rm    $SYSFS/iscsi/$name/tpgt_$tid/lun/lun_*/$lnk
+    rmdir $SYSFS/iscsi/$name/tpgt_$tid/lun/lun_*
+    rmdir $SYSFS/iscsi/$name/tpgt_$tid
+    rmdir $SYSFS/iscsi/$name
+
+    rmdir $SYSFS/core/iblock_$tid/$name
+    rmdir $SYSFS/core/iblock_$tid
+done

lib/libshare/destroy_scst.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+# This is a script to somply unshare all SCST targets, without going through
+# ZFS. Mostly used for testing...
+
+SYSFS=/sys/kernel/scst_tgt
+
+cd $SYSFS/targets/iscsi/
+if [ -z "$*" ]; then
+    targets=`echo iqn.*`
+else
+    targets=`echo $*`
+fi
+
+for name in $targets; do
+    find $SYSFS/targets/iscsi/$name/sessions/* -type d > /dev/null 2>&1
+    if [ "$?" -eq "1" ]; then
+        [ ! -f "$SYSFS/targets/iscsi/$name/enabled" ] && continue
+
+	#scstadmin -noprompt -disable_target $name -driver iscsi
+	echo 0 > $SYSFS/targets/iscsi/$name/enabled
+
+	#scstadmin -noprompt -close_dev $dev -handler vdisk_blockio
+	dev=`/bin/ls -l $SYSFS/targets/iscsi/$name/luns/0/device | sed 's@.*/@@'`
+	echo "del_device $dev" > $SYSFS/handlers/vdisk_blockio/mgmt
+
+	#scstadmin -noprompt -rem_target $name -driver iscsi
+	echo "del_target $name" > $SYSFS/targets/iscsi/mgmt
+    else
+	echo "Can't destroy $name - have sessions"
+    fi
+done