From 90a0e97c7be9da39fd54600228e006b98667ad56 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Tue, 18 Jun 2013 12:24:28 +0200 Subject: [PATCH 1/2] eject: Check host_status and driver_status when using SG_IO. Based on Suse patch, originally from Anna Bernathova , May 2008 SG_IO completion status is weird but still well defined. You'll need to check both host_status, driver_status and status to determine that a command actually succeeded. -- Tejun Heo, May 2008 Note that we also need to check driver_status and sense_buffer to detect situation when there is no medium. It's valid request to call eject(8) for device with no medium. References: https://bugzilla.novell.com/show_bug.cgi?id=358033 Signed-off-by: Anna Bernathova Signed-off-by: Karel Zak --- sys-utils/eject.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/sys-utils/eject.c b/sys-utils/eject.c index 4ec69e7..f98f227 100644 --- a/sys-utils/eject.c +++ b/sys-utils/eject.c @@ -53,6 +53,14 @@ #include "pathnames.h" #include "sysfs.h" +/* + * sg_io_hdr_t driver_status -- see kernel include/scsi/scsi.h + */ +#ifndef DRIVER_SENSE +# define DRIVER_SENSE 0x08 +#endif + + #define EJECT_DEFAULT_DEVICE "/dev/cdrom" @@ -604,17 +612,27 @@ static int eject_scsi(int fd) io_hdr.cmdp = allowRmBlk; status = ioctl(fd, SG_IO, (void *)&io_hdr); - if (status < 0) + if (status < 0 || io_hdr.host_status || io_hdr.driver_status) return 0; io_hdr.cmdp = startStop1Blk; status = ioctl(fd, SG_IO, (void *)&io_hdr); - if (status < 0) + if (status < 0 || io_hdr.host_status) + return 0; + + /* Ignore errors when there is not medium -- in this case driver sense + * buffer sets MEDIUM NOT PRESENT (3a) bit. For more details see: + * http://www.tldp.org/HOWTO/archived/SCSI-Programming-HOWTO/SCSI-Programming-HOWTO-22.html#sec-sensecodes + * -- kzak Jun 2013 + */ + if (io_hdr.driver_status != 0 && + !(io_hdr.driver_status == DRIVER_SENSE && io_hdr.sbp && + io_hdr.sbp[12] == 0x3a)) return 0; io_hdr.cmdp = startStop2Blk; status = ioctl(fd, SG_IO, (void *)&io_hdr); - if (status < 0) + if (status < 0 || io_hdr.host_status || io_hdr.driver_status) return 0; /* force kernel to reread partition table when new disc inserted */ -- 1.8.1.4