forked from Minki/linux
26cf591e6d
Further to a January 2013 thread titled: "[PATCH] SG_SCSI_RESET ioctl
should only perform requested operation" by Jeremy Linton a patch (v3)
is presented that expands the existing ioctl to include "no_escalate"
versions to the existing resets. This requires no changes to SCSI low
level drivers (LLDs); it adds several more finely tuned reset options
to the user space. For example:
/* This call remains the same, with the same escalating semantics
* if the device (LU) reset fail. That is: on failure to try a
* target reset and if that fails, try a bus reset, and if that fails
* try a host (i.e. LLD) reset. */
val = SG_SCSI_RESET_DEVICE;
res = ioctl(<sg_or_block_fd>, SG_SCSI_RESET, &val);
/* What follows is a new option introduced by this patch series. Only
* a device reset is attempted. If that fails then an appropriate
* error code is provided. N.B. There is no reset escalation. */
val = SG_SCSI_RESET_DEVICE | SG_SCSI_RESET_NO_ESCALATE;
res = ioctl(<sg_or_block_fd>, SG_SCSI_RESET, &val);
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Jeremy Linton <jlinton@tributary.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
101 lines
3.0 KiB
C
101 lines
3.0 KiB
C
#ifndef _SCSI_SCSI_EH_H
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#define _SCSI_SCSI_EH_H
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#include <linux/scatterlist.h>
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#include <scsi/scsi_cmnd.h>
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struct scsi_device;
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struct Scsi_Host;
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/*
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* This is a slightly modified SCSI sense "descriptor" format header.
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* The addition is to allow the 0x70 and 0x71 response codes. The idea
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* is to place the salient data from either "fixed" or "descriptor" sense
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* format into one structure to ease application processing.
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*
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* The original sense buffer should be kept around for those cases
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* in which more information is required (e.g. the LBA of a MEDIUM ERROR).
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*/
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struct scsi_sense_hdr { /* See SPC-3 section 4.5 */
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u8 response_code; /* permit: 0x0, 0x70, 0x71, 0x72, 0x73 */
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u8 sense_key;
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u8 asc;
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u8 ascq;
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u8 byte4;
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u8 byte5;
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u8 byte6;
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u8 additional_length; /* always 0 for fixed sense format */
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};
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static inline int scsi_sense_valid(struct scsi_sense_hdr *sshdr)
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{
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if (!sshdr)
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return 0;
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return (sshdr->response_code & 0x70) == 0x70;
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}
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extern void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
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struct list_head *done_q);
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extern void scsi_eh_flush_done_q(struct list_head *done_q);
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extern void scsi_report_bus_reset(struct Scsi_Host *, int);
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extern void scsi_report_device_reset(struct Scsi_Host *, int, int);
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extern int scsi_block_when_processing_errors(struct scsi_device *);
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extern int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
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struct scsi_sense_hdr *sshdr);
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extern int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
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struct scsi_sense_hdr *sshdr);
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static inline int scsi_sense_is_deferred(struct scsi_sense_hdr *sshdr)
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{
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return ((sshdr->response_code >= 0x70) && (sshdr->response_code & 1));
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}
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extern const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
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int desc_type);
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extern int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
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u64 * info_out);
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extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq);
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/*
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* Reset request from external source
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* Note: if SCSI_TRY_RESET_DEVICE fails then it will escalate to
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* SCSI_TRY_RESET_TARGET which if it fails will escalate to
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* SCSI_TRY_RESET_BUS which if it fails will escalate to SCSI_TRY_RESET_HOST.
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* To prevent escalation OR with SCSI_TRY_RESET_NO_ESCALATE.
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*/
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#define SCSI_TRY_RESET_DEVICE 1
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#define SCSI_TRY_RESET_BUS 2
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#define SCSI_TRY_RESET_HOST 3
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#define SCSI_TRY_RESET_TARGET 4
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#define SCSI_TRY_RESET_NO_ESCALATE 0x100 /* OR-ed to prior defines */
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extern int scsi_reset_provider(struct scsi_device *, int);
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struct scsi_eh_save {
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/* saved state */
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int result;
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enum dma_data_direction data_direction;
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unsigned underflow;
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unsigned char cmd_len;
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unsigned char prot_op;
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unsigned char *cmnd;
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struct scsi_data_buffer sdb;
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struct request *next_rq;
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/* new command support */
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unsigned char eh_cmnd[BLK_MAX_CDB];
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struct scatterlist sense_sgl;
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};
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extern void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
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struct scsi_eh_save *ses, unsigned char *cmnd,
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int cmnd_size, unsigned sense_bytes);
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extern void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
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struct scsi_eh_save *ses);
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#endif /* _SCSI_SCSI_EH_H */
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