[PATCH AUTOSEL 4.4 32/37] cdrom: respect device capabilities during opening action

[Sasha Levin <sashal@kernel.org>]

From: Diego Elio Pettenò <flameeyes@flameeyes.com>

[ Upstream commit 366ba7c71ef77c08d06b18ad61b26e2df7352338 ]

Reading the TOC only works if the device can play audio, otherwise
these commands fail (and possibly bring the device to an unhealthy
state.)

Similarly, cdrom_mmc3_profile() should only be called if the device
supports generic packet commands.

To: Jens Axboe <axboe@kernel.dk>
Cc: linux-kernel@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Diego Elio Pettenò <flameeyes@flameeyes.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cdrom/cdrom.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index aee23092f50e9..2c5feb6b4a998 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -998,6 +998,12 @@ static void cdrom_count_tracks(struct cdrom_device_info *cdi, tracktype *tracks)
 	tracks->xa = 0;
 	tracks->error = 0;
 	cd_dbg(CD_COUNT_TRACKS, "entering cdrom_count_tracks\n");
+
+	if (!CDROM_CAN(CDC_PLAY_AUDIO)) {
+		tracks->error = CDS_NO_INFO;
+		return;
+	}
+
 	/* Grab the TOC header so we can see how many tracks there are */
 	ret = cdi->ops->audio_ioctl(cdi, CDROMREADTOCHDR, &header);
 	if (ret) {
@@ -1164,7 +1170,8 @@ int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev,
 		ret = open_for_data(cdi);
 		if (ret)
 			goto err;
-		cdrom_mmc3_profile(cdi);
+		if (CDROM_CAN(CDC_GENERIC_PACKET))
+			cdrom_mmc3_profile(cdi);
 		if (mode & FMODE_WRITE) {
 			ret = -EROFS;
 			if (cdrom_open_write(cdi))
@@ -2863,6 +2870,9 @@ int cdrom_get_last_written(struct cdrom_device_info *cdi, long *last_written)
 	   it doesn't give enough information or fails. then we return
 	   the toc contents. */
 use_toc:
+	if (!CDROM_CAN(CDC_PLAY_AUDIO))
+		return -ENOSYS;
+
 	toc.cdte_format = CDROM_MSF;
 	toc.cdte_track = CDROM_LEADOUT;
 	if ((ret = cdi->ops->audio_ioctl(cdi, CDROMREADTOCENTRY, &toc)))
-- 
2.20.1