xfsrestore: fix on-media inventory stream unpacking

xfsdump can create multiple streams, when restoring the online inventory
with multiple streams we fail to process these and assert when the
inventory buffer is not fully decoded.

[root@rhel8 ~]# xfsdump -L "Test1" -f /dev/nst0 -M tape1 -f /dev/nst1 -M tape2 /boot
xfsdump: using scsi tape (drive_scsitape) strategy
xfsdump: using scsi tape (drive_scsitape) strategy
xfsdump: version 3.1.8 (dump format 3.0) - type ^C for status and control
xfsdump: level 0 dump of rhel8:/boot
xfsdump: dump date: Thu Oct  6 13:50:45 2022
xfsdump: session id: aa25fa48-4493-45c7-9027-61e53e486445
xfsdump: session label: "Test1"
xfsdump: ino map phase 1: constructing initial dump list
xfsdump: ino map phase 2: skipping (no pruning necessary)
xfsdump: ino map phase 3: identifying stream starting points
xfsdump: stream 0: ino 133 offset 0 to ino 28839 offset 0
xfsdump: stream 1: ino 28839 offset 0 to end
xfsdump: ino map construction complete
xfsdump: estimated dump size: 328720704 bytes
xfsdump: estimated dump size per stream: 164375728 bytes
xfsdump: /var/lib/xfsdump/inventory created
xfsdump: drive 0: preparing drive
xfsdump: drive 1: preparing drive
xfsdump: drive 1: creating dump session media file 0 (media 0, file 0)
xfsdump: drive 1: dumping ino map
xfsdump: drive 1: dumping non-directory files
xfsdump: drive 0: creating dump session media file 0 (media 0, file 0)
xfsdump: drive 0: dumping ino map
xfsdump: drive 0: dumping directories
xfsdump: drive 0: dumping non-directory files
xfsdump: drive 1: ending media file
xfsdump: drive 1: media file size 166723584 bytes
xfsdump: drive 1: waiting for synchronized session inventory dump
xfsdump: drive 0: ending media file
xfsdump: drive 0: media file size 165675008 bytes
xfsdump: drive 0: waiting for synchronized session inventory dump
xfsdump: drive 0: dumping session inventory
xfsdump: drive 0: beginning inventory media file
xfsdump: drive 0: media file 1 (media 0, file 1)
xfsdump: drive 0: ending inventory media file
xfsdump: drive 0: inventory media file size 2097152 bytes
xfsdump: drive 0: writing stream terminator
xfsdump: drive 0: beginning media stream terminator
xfsdump: drive 0: media file 2 (media 0, file 2)
xfsdump: drive 0: ending media stream terminator
xfsdump: drive 0: media stream terminator size 1048576 bytes
xfsdump: drive 1: dumping session inventory
xfsdump: drive 1: beginning inventory media file
xfsdump: drive 1: media file 1 (media 0, file 1)
xfsdump: drive 1: ending inventory media file
xfsdump: drive 1: inventory media file size 2097152 bytes
xfsdump: drive 1: writing stream terminator
xfsdump: drive 1: beginning media stream terminator
xfsdump: drive 1: media file 2 (media 0, file 2)
xfsdump: drive 1: ending media stream terminator
xfsdump: drive 1: media stream terminator size 1048576 bytes
xfsdump: dump size (non-dir files) : 328189016 bytes
xfsdump: dump complete: 4 seconds elapsed
xfsdump: Dump Summary:
xfsdump:   stream 0 /dev/nst0 OK (success)
xfsdump:   stream 1 /dev/nst1 OK (success)
xfsdump: Dump Status: SUCCESS
[root@rhel8 ~]# xfsdump -I
file system 0:
	fs id:		26dd5aa0-b901-4cf5-9b68-0c5753cb3ab8
	session 0:
		mount point:	rhel8:/boot
		device:		rhel8:/dev/sda1
		time:		Thu Oct  6 13:50:45 2022
		session label:	"Test1"
		session id:	aa25fa48-4493-45c7-9027-61e53e486445
		level:		0
		resumed:	NO
		subtree:	NO
		streams:	2
		stream 0:
			pathname:	/dev/nst0
			start:		ino 133 offset 0
			end:		ino 28839 offset 0
			interrupted:	NO
			media files:	2
			media file 0:
				mfile index:	0
				mfile type:	data
				mfile size:	165675008
				mfile start:	ino 133 offset 0
				mfile end:	ino 28839 offset 0
				media label:	"tape1"
				media id:	adb31f2a-f026-4597-a20a-326f28ecbaf1
			media file 1:
				mfile index:	1
				mfile type:	inventory
				mfile size:	2097152
				media label:	"tape1"
				media id:	adb31f2a-f026-4597-a20a-326f28ecbaf1
		stream 1:
			pathname:	/dev/nst1
			start:		ino 28839 offset 0
			end:		ino 1572997 offset 0
			interrupted:	NO
			media files:	2
			media file 0:
				mfile index:	0
				mfile type:	data
				mfile size:	166723584
				mfile start:	ino 28839 offset 0
				mfile end:	ino 1572997 offset 0
				media label:	"tape2"
				media id:	22224f02-b6c7-47d5-ad61-a61ba071c8a8
			media file 1:
				mfile index:	1
				mfile type:	inventory
				mfile size:	2097152
				media label:	"tape2"
				media id:	22224f02-b6c7-47d5-ad61-a61ba071c8a8
xfsdump: Dump Status: SUCCESS
[root@rhel8 ~]# mv /var/lib/xfsdump/inventory /var/lib/xfsdump/inventory_two_sessions
[root@rhel8 ~]# xfsdump -I
xfsdump: Dump Status: SUCCESS

[root@rhel8 ~]# xfsrestore -L Test1 -f /dev/nst0 /tmp/test1/
xfsrestore: using scsi tape (drive_scsitape) strategy
xfsrestore: version 3.1.8 (dump format 3.0) - type ^C for status and control
xfsrestore: searching media for dump
xfsrestore: preparing drive
xfsrestore: examining media file 2
xfsrestore: found dump matching specified label:
xfsrestore: hostname: rhel8
xfsrestore: mount point: /boot
xfsrestore: volume: /dev/sda1
xfsrestore: session time: Thu Oct  6 13:50:45 2022
xfsrestore: level: 0
xfsrestore: session label: "Test1"
xfsrestore: media label: "tape1"
xfsrestore: file system id: 26dd5aa0-b901-4cf5-9b68-0c5753cb3ab8
xfsrestore: session id: aa25fa48-4493-45c7-9027-61e53e486445
xfsrestore: media id: adb31f2a-f026-4597-a20a-326f28ecbaf1
xfsrestore: searching media for directory dump
xfsrestore: rewinding
xfsrestore: examining media file 0
xfsrestore: reading directories
xfsrestore: 9 directories and 320 entries processed
xfsrestore: directory post-processing
xfsrestore: restoring non-directory files
xfsrestore: examining media file 1
xfsrestore: inv_stobj.c:1119: stobj_unpack_sessinfo: Assertion `(size_t) ( p - (char *) bufp ) == bufsz' failed.
Aborted (core dumped)

Make sure we unpack multiple streams when restoring the online
inventory from media.

Signed-off-by: Donald Douwsma <ddouwsma@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
diff --git a/inventory/inv_stobj.c b/inventory/inv_stobj.c
index cdf3300..42b86dc 100644
--- a/inventory/inv_stobj.c
+++ b/inventory/inv_stobj.c
@@ -1065,25 +1065,26 @@
 		return BOOL_FALSE;
 	}
 
+	/* get the seshdr and then, the remainder of the session */
 	xlate_invt_seshdr((invt_seshdr_t *)p, (invt_seshdr_t *)tmpbuf, 1);
 	bcopy(tmpbuf, p, sizeof(invt_seshdr_t));
-
-	/* get the seshdr and then, the remainder of the session */
 	s->seshdr = (invt_seshdr_t *)p;
 	s->seshdr->sh_sess_off = -1;
 	p += sizeof(invt_seshdr_t);
 
-
 	xlate_invt_session((invt_session_t *)p, (invt_session_t *)tmpbuf, 1);
 	bcopy (tmpbuf, p, sizeof(invt_session_t));
 	s->ses = (invt_session_t *)p;
 	p += sizeof(invt_session_t);
 
 	/* the array of all the streams belonging to this session */
-	xlate_invt_stream((invt_stream_t *)p, (invt_stream_t *)tmpbuf, 1);
-	bcopy(tmpbuf, p, sizeof(invt_stream_t));
 	s->strms = (invt_stream_t *)p;
-	p += s->ses->s_cur_nstreams * sizeof(invt_stream_t);
+	for (i = 0; i < s->ses->s_cur_nstreams; i++) {
+		xlate_invt_stream((invt_stream_t *)p,
+				  (invt_stream_t *)tmpbuf, 1);
+		bcopy(tmpbuf, p, sizeof(invt_stream_t));
+		p += sizeof(invt_stream_t);
+	}
 
 	/* all the media files */
 	s->mfiles = (invt_mediafile_t *)p;