alistair23-linux/include/scsi/scsi_eh.h
Damien Le Moal 8f8fed0cdb scsi: core: save/restore command resid for error handling
When a non-passthrough command is terminated with CHECK CONDITION, request
sense is executed by hijacking the command descriptor. Since
scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() do not save/restore the
original command resid, the value returned on failure of the original
command is lost and replaced with the value set by the execution of the
request sense command. This value may in many instances be unaligned to the
device sector size, causing sd_done() to print a warning message about the
incorrect unaligned resid before the command is retried.

Fix this problem by saving the original command residual in struct
scsi_eh_save using scsi_eh_prep_cmnd() and restoring it in
scsi_eh_restore_cmnd(). In addition, to make sure that the request sense
command is executed with a correctly initialized command structure, also
reset the residual to 0 in scsi_eh_prep_cmnd() after saving the original
command value in struct scsi_eh_save.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191001074839.1994-1-damien.lemoal@wdc.com
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-03 21:43:04 -04:00

56 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _SCSI_SCSI_EH_H
#define _SCSI_SCSI_EH_H
#include <linux/scatterlist.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_common.h>
struct scsi_device;
struct Scsi_Host;
extern void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
struct list_head *done_q);
extern void scsi_eh_flush_done_q(struct list_head *done_q);
extern void scsi_report_bus_reset(struct Scsi_Host *, int);
extern void scsi_report_device_reset(struct Scsi_Host *, int, int);
extern int scsi_block_when_processing_errors(struct scsi_device *);
extern bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
struct scsi_sense_hdr *sshdr);
extern int scsi_check_sense(struct scsi_cmnd *);
static inline bool scsi_sense_is_deferred(const struct scsi_sense_hdr *sshdr)
{
return ((sshdr->response_code >= 0x70) && (sshdr->response_code & 1));
}
extern bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len,
u64 *info_out);
extern int scsi_ioctl_reset(struct scsi_device *, int __user *);
struct scsi_eh_save {
/* saved state */
int result;
unsigned int resid_len;
int eh_eflags;
enum dma_data_direction data_direction;
unsigned underflow;
unsigned char cmd_len;
unsigned char prot_op;
unsigned char *cmnd;
struct scsi_data_buffer sdb;
/* new command support */
unsigned char eh_cmnd[BLK_MAX_CDB];
struct scatterlist sense_sgl;
};
extern void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
struct scsi_eh_save *ses, unsigned char *cmnd,
int cmnd_size, unsigned sense_bytes);
extern void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
struct scsi_eh_save *ses);
#endif /* _SCSI_SCSI_EH_H */