mirror of
https://github.com/torvalds/linux.git
synced 2024-12-30 14:52:05 +00:00
79b9677d88
Some broken devices indicates that media has changed on every
GET_EVENT_STATUS_NOTIFICATION. This translates into MEDIA_CHANGE
uevent on every open() which lets udev run into a loop.
Verify GET_EVENT result against TUR and if it generates spurious
events for several times in a row, ignore the GET_EVENT events, and
trust only the TUR status.
This is the log of a USB stick with a (broken) fake CDROM drive:
scsi 5:0:0:0: Direct-Access SanDisk U3 Cruzer Micro 8.02 PQ: 0 ANSI: 0 CCS
sd 5:0:0:0: Attached scsi generic sg3 type 0
scsi 5:0:0:1: CD-ROM SanDisk U3 Cruzer Micro 8.02 PQ: 0 ANSI: 0
sd 5:0:0:0: [sdb] Attached SCSI removable disk
sr2: scsi3-mmc drive: 48x/48x tray
sr 5:0:0:1: Attached scsi CD-ROM sr2
sr 5:0:0:1: Attached scsi generic sg4 type 5
sr2: GET_EVENT and TUR disagree continuously, suppress GET_EVENT events
sd 5:0:0:0: [sdb] 31777279 512-byte logical blocks: (16.2 GB/15.1 GiB)
sd 5:0:0:0: [sdb] No Caching mode page present
sd 5:0:0:0: [sdb] Assuming drive cache: write through
sd 5:0:0:0: [sdb] No Caching mode page present
sd 5:0:0:0: [sdb] Assuming drive cache: write through
sdb: sdb1
-tj: Updated to consider only spurious GET_EVENT events among
different types of disagreement and allow using TUR for kernel
event polling after GET_EVENT is ignored.
Reported-By: Markus Rathgeb maggu2810@googlemail.com
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org # >= v2.6.38, fixes udev busy looping w/ certain devices
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
78 lines
2.5 KiB
C
78 lines
2.5 KiB
C
/*
|
|
* sr.h by David Giller
|
|
* CD-ROM disk driver header file
|
|
*
|
|
* adapted from:
|
|
* sd.h Copyright (C) 1992 Drew Eckhardt
|
|
* SCSI disk driver header file by
|
|
* Drew Eckhardt
|
|
*
|
|
* <drew@colorado.edu>
|
|
*
|
|
* Modified by Eric Youngdale eric@andante.org to
|
|
* add scatter-gather, multiple outstanding request, and other
|
|
* enhancements.
|
|
*/
|
|
|
|
#ifndef _SR_H
|
|
#define _SR_H
|
|
|
|
#include <linux/genhd.h>
|
|
#include <linux/kref.h>
|
|
|
|
#define MAX_RETRIES 3
|
|
#define SR_TIMEOUT (30 * HZ)
|
|
|
|
struct scsi_device;
|
|
|
|
/* The CDROM is fairly slow, so we need a little extra time */
|
|
/* In fact, it is very slow if it has to spin up first */
|
|
#define IOCTL_TIMEOUT 30*HZ
|
|
|
|
|
|
typedef struct scsi_cd {
|
|
struct scsi_driver *driver;
|
|
unsigned capacity; /* size in blocks */
|
|
struct scsi_device *device;
|
|
unsigned int vendor; /* vendor code, see sr_vendor.c */
|
|
unsigned long ms_offset; /* for reading multisession-CD's */
|
|
unsigned use:1; /* is this device still supportable */
|
|
unsigned xa_flag:1; /* CD has XA sectors ? */
|
|
unsigned readcd_known:1; /* drive supports READ_CD (0xbe) */
|
|
unsigned readcd_cdda:1; /* reading audio data using READ_CD */
|
|
unsigned media_present:1; /* media is present */
|
|
|
|
/* GET_EVENT spurious event handling, blk layer guarantees exclusion */
|
|
int tur_mismatch; /* nr of get_event TUR mismatches */
|
|
bool tur_changed:1; /* changed according to TUR */
|
|
bool get_event_changed:1; /* changed according to GET_EVENT */
|
|
bool ignore_get_event:1; /* GET_EVENT is unreliable, use TUR */
|
|
|
|
struct cdrom_device_info cdi;
|
|
/* We hold gendisk and scsi_device references on probe and use
|
|
* the refs on this kref to decide when to release them */
|
|
struct kref kref;
|
|
struct gendisk *disk;
|
|
} Scsi_CD;
|
|
|
|
int sr_do_ioctl(Scsi_CD *, struct packet_command *);
|
|
|
|
int sr_lock_door(struct cdrom_device_info *, int);
|
|
int sr_tray_move(struct cdrom_device_info *, int);
|
|
int sr_drive_status(struct cdrom_device_info *, int);
|
|
int sr_disk_status(struct cdrom_device_info *);
|
|
int sr_get_last_session(struct cdrom_device_info *, struct cdrom_multisession *);
|
|
int sr_get_mcn(struct cdrom_device_info *, struct cdrom_mcn *);
|
|
int sr_reset(struct cdrom_device_info *);
|
|
int sr_select_speed(struct cdrom_device_info *cdi, int speed);
|
|
int sr_audio_ioctl(struct cdrom_device_info *, unsigned int, void *);
|
|
|
|
int sr_is_xa(Scsi_CD *);
|
|
|
|
/* sr_vendor.c */
|
|
void sr_vendor_init(Scsi_CD *);
|
|
int sr_cd_check(struct cdrom_device_info *);
|
|
int sr_set_blocklength(Scsi_CD *, int blocklength);
|
|
|
|
#endif
|