summaryrefslogtreecommitdiff
path: root/drivers/scsi/scsi_error.c
AgeCommit message (Collapse)AuthorFilesLines
2014-04-22[SCSI] More USB deadlock fixesJames Bottomley1-0/+1
This patch fixes a corner case in the previous USB Deadlock fix patch (12023e7 [SCSI] Fix USB deadlock caused by SCSI error handling). The scenario is abort command, set flag, abort completes, send TUR, TUR doesn't return, so we now try to abort the TUR, but scsi_abort_eh_cmnd() will skip the abort because the flag is set and move straight to reset. Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-04-22[SCSI] Fix USB deadlock caused by SCSI error handlingHannes Reinecke1-0/+1
USB requires that every command be aborted first before we escalate to reset. In particular, USB will deadlock if we try to reset first before aborting the command. Unfortunately, the flag we use to tell if a command has already been aborted: SCSI_EH_ABORT_SCHEDULED is not cleared properly leading to cases where we can requeue a command with the flag set and proceed immediately to reset if it fails (thus causing USB to deadlock). Fix by clearing the SCSI_EH_ABORT_SCHEDULED flag if it has been set. Which means this will be the second time scsi_abort_command() has been called for the same command. IE the first abort went out, did its thing, but now the same command has timed out again. So this flag gets cleared, and scsi_abort_command() returns FAILED, and _no_ asynchronous abort is being scheduled. scsi_times_out() will then proceed to call scsi_eh_scmd_add(). But as we've cleared the SCSI_EH_ABORT_SCHEDULED flag the SCSI_EH_CANCEL_CMD flag will continue to be set, and the command will be aborted with the main SCSI EH routine. Reported-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Andreas Reis <andreas.reis@gmail.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-04-22[SCSI] Fix command result state propagationAlan Stern1-0/+1
We're seeing a case where the contents of scmd->result isn't being reset after a SCSI command encounters an error, is resubmitted, times out and then gets handled. The error handler acts on the stale result of the previous error instead of the timeout. Fix this by properly zeroing the scmd->status before the command is resubmitted. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-04-22[SCSI] Fix spurious request sense in error handlingJames Bottomley1-0/+9
We unconditionally execute scsi_eh_get_sense() to make sure all failed commands that should have sense attached, do. However, the routine forgets that some commands, because of the way they fail, will not have any sense code ... we should not bother them with a REQUEST_SENSE command. Fix this by testing to see if we actually got a CHECK_CONDITION return and skip asking for sense if we don't. Tested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15[SCSI] do not manipulate device reference counts in scsi_get/put_commandChristoph Hellwig1-0/+6
Many callers won't need this and we can optimize them away. In addition the handling in the __-prefixed variants was inconsistant to start with. Based on an earlier patch from Bart Van Assche. [jejb: fix kerneldoc probelm picked up by Fengguang Wu] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19[SCSI] Set the minimum valid value of 'eh_deadline' as 0Ren Mingxin1-13/+21
The former minimum valid value of 'eh_deadline' is 1s, which means the earliest occasion to shorten EH is 1 second later since a command is failed or timed out. But if we want to skip EH steps ASAP, we have to wait until the first EH step is finished. If the duration of the first EH step is long, this waiting time is excruciating. So, it is necessary to accept 0 as the minimum valid value for 'eh_deadline'. According to my test, with Hannes' patchset 'New EH command timeout handler' as well, the minimum IO time is improved from 73s (eh_deadline = 1) to 43s(eh_deadline = 0) when commands are timed out by disabling RSCN and target port. Signed-off-by: Ren Mingxin <renmx@cn.fujitsu.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19[SCSI] Unlock accesses to eh_deadlineHannes Reinecke1-35/+9
32bit accesses are guaranteed to be atomic, so we can remove the spinlock when checking for eh_deadline. We only need to make sure to catch any updates which might happened during the call to time_before(); if so we just recheck with the correct value. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19[SCSI] improved eh timeout handlerHannes Reinecke1-13/+138
When a command runs into a timeout we need to send an 'ABORT TASK' TMF. This is typically done by the 'eh_abort_handler' LLDD callback. Conceptually, however, this function is a normal SCSI command, so there is no need to enter the error handler. This patch implements a new scsi_abort_command() function which invokes an asynchronous function scsi_eh_abort_handler() to abort the commands via the usual 'eh_abort_handler'. If abort succeeds the command is either retried or terminated, depending on the number of allowed retries. However, 'eh_eflags' records the abort, so if the retry would fail again the command is pushed onto the error handler without trying to abort it (again); it'll be cleared up from SCSI EH. [hare: smatch detected stray switch fixed] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19[SCSI] Fix erratic device offline during EHJames Bottomley1-9/+17
Commit 18a4d0a22ed6c54b67af7718c305cd010f09ddf8 (Handle disk devices which can not process medium access commands) was introduced to offline any device which cannot process medium access commands. However, commit 3eef6257de48ff84a5d98ca533685df8a3beaeb8 (Reduce error recovery time by reducing use of TURs) reduced the number of TURs by sending it only on the first failing command, which might or might not be a medium access command. So in combination this results in an erratic device offlining during EH; if the command where the TUR was sent upon happens to be a medium access command the device will be set offline, if not everything proceeds as normal. This patch moves the check to the final test, eliminating this problem. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-10-25[SCSI] scsi_error: Escalate to LUN reset if abort failsHannes Reinecke1-7/+9
If a command abort fails there is a fair chance that all other aborts will be failing, too. So we should be calling LUN reset directly after the first failed abort and skip aborting the remaining commands. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-10-25[SCSI] Add 'eh_deadline' to limit SCSI EH runtimeHannes Reinecke1-6/+124
This patchs adds an 'eh_deadline' sysfs attribute to the scsi host which limits the overall runtime of the SCSI EH. The 'eh_deadline' value is stored in the now obsolete field 'resetting'. When a command is failed the start time of the EH is stored in 'last_reset'. If the overall runtime of the SCSI EH is longer than last_reset + eh_deadline, the EH is short-circuited and falls through to issue a host reset only. [jejb: add comments in Scsi_Host about new fields] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-26[SCSI] Generate uevents on certain unit attention codesEwan D. Milne1-20/+80
Generate a uevent when the following Unit Attention ASC/ASCQ codes are received: 2A/01 MODE PARAMETERS CHANGED 2A/09 CAPACITY DATA HAS CHANGED 38/07 THIN PROVISIONING SOFT THRESHOLD REACHED 3F/03 INQUIRY DATA HAS CHANGED 3F/0E REPORTED LUNS DATA HAS CHANGED Log kernel messages when the following Unit Attention ASC/ASCQ codes are received that are not as specific as those above: 2A/xx PARAMETERS CHANGED 3F/xx TARGET OPERATING CONDITIONS HAVE CHANGED Added logic to set expecting_lun_change for other LUNs on the target after REPORTED LUNS DATA HAS CHANGED is received, so that duplicate uevents are not generated, and clear expecting_lun_change when a REPORT LUNS command completes, in accordance with the SPC-3 specification regarding reporting of the 3F 0E ASC/ASCQ UA. [jejb: remove SPC3 test in scsi_report_lun_change and some docbook fixes and unused variable fix, both reported by Fengguang Wu] Signed-off-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-23[SCSI] Return ENODATA on medium errorHannes Reinecke1-1/+1
When a medium error is detected the SCSI stack should return ENODATA to the upper layers. [jejb: fix whitespace error] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-23[SCSI] return ENOSPC on thin provisioning failureHannes Reinecke1-1/+6
When the thin provisioning hard threshold is reached we should return ENOSPC to inform upper layers about this fact. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-23[SCSI] Set hostbyte status in scsi_check_sense()Hannes Reinecke1-14/+7
We should be modifying the host_byte status in scsi_check_sense() directly; this saves us to introduce a special return code for each and every condition. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-07-04Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds1-4/+3
Pull first round of SCSI updates from James Bottomley: "The patch set is mostly driver updates (usf, zfcp, lpfc, mpt2sas, megaraid_sas, bfa, ipr) and a few bug fixes. Also of note is that the Buslogic driver has been rewritten to a better coding style and 64 bit support added. We also removed the libsas limitation on 16 bytes for the command size (currently no drivers make use of this)" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (101 commits) [SCSI] megaraid: minor cut and paste error fixed. [SCSI] ufshcd-pltfrm: remove unnecessary dma_set_coherent_mask() call [SCSI] ufs: fix register address in UIC error interrupt handling [SCSI] ufshcd-pltfrm: add missing empty slot in ufs_of_match[] [SCSI] ufs: use devres functions for ufshcd [SCSI] ufs: Fix the response UPIU length setting [SCSI] ufs: rework link start-up process [SCSI] ufs: remove version check before IS reg clear [SCSI] ufs: amend interrupt configuration [SCSI] ufs: wrap the i/o access operations [SCSI] storvsc: Update the storage protocol to win8 level [SCSI] storvsc: Increase the value of scsi timeout for storvsc devices [SCSI] MAINTAINERS: Add myself as the maintainer for BusLogic SCSI driver [SCSI] BusLogic: Port driver to 64-bit. [SCSI] BusLogic: Fix style issues [SCSI] libiscsi: Added new boot entries in the session sysfs [SCSI] aacraid: Fix for arrays are going offline in the system. System hangs [SCSI] ipr: IOA Status Code(IOASC) update [SCSI] sd: Update WRITE SAME heuristics [SCSI] fnic: potential dead lock in fnic_is_abts_pending() ...
2013-06-04[SCSI] Allow error handling timeout to be specifiedMartin K. Petersen1-4/+3
Introduce eh_timeout which can be used for error handling purposes. This was previously hardcoded to 10 seconds in the SCSI error handling code. However, for some fast-fail scenarios it is necessary to be able to tune this as it can take several iterations (bus device, target, bus, controller) before we give up. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-05-28scsi: Spelling hsot -> hostGeert Uytterhoeven1-1/+1
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-05-10[SCSI] Handle MLQUEUE busy response in scsi_send_eh_cmndHannes Reinecke1-10/+27
scsi_send_eh_cmnd() is calling queuecommand() directly, so it needs to check the return value here. The only valid return codes for queuecommand() are 'busy' states, so we need to wait for a bit to allow the LLDD to recover. Based on an earlier patch from Wen Xiong. [jejb: fix confusion between msec and jiffies values and other issues] [bvanassche: correct stall_for interval] Cc: Wen Xiong <wenxiong@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-10-09[SCSI] Shorten the path length of scsi_cmd_to_driver()Li Zhong1-3/+5
This patch tries to shorten the path length of scsi_cmd_to_driver(). As only REQ_TYPE_BLOCK_PC commands can be submitted without a driver, so we could avoid the related NULL checking, as long as we make sure we don't use it for REQ_TYPE_BLOCK_PC type commands. Plus, this fixes a bug where you get different behaviors from REQ_TYPE_BLOCK_PC commands when a driver is and isn't attached. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-08-22[SCSI] Fix 'Device not ready' issue on mpt2sasJames Bottomley1-0/+10
This is a particularly nasty SCSI ATA Translation Layer (SATL) problem. SAT-2 says (section 8.12.2) if the device is in the stopped state as the result of processing a START STOP UNIT command (see 9.11), then the SATL shall terminate the TEST UNIT READY command with CHECK CONDITION status with the sense key set to NOT READY and the additional sense code of LOGICAL UNIT NOT READY, INITIALIZING COMMAND REQUIRED; mpt2sas internal SATL seems to implement this. The result is very confusing standby behaviour (using hdparm -y). If you suspend a drive and then send another command, usually it wakes up. However, if the next command is a TEST UNIT READY, the SATL sees that the drive is suspended and proceeds to follow the SATL rules for this, returning NOT READY to all subsequent commands. This means that the ordering of TEST UNIT READY is crucial: if you send TUR and then a command, you get a NOT READY to both back. If you send a command and then a TUR, you get GOOD status because the preceeding command woke the drive. This bit us badly because commit 85ef06d1d252f6a2e73b678591ab71caad4667bb Author: Tejun Heo <tj@kernel.org> Date: Fri Jul 1 16:17:47 2011 +0200 block: flush MEDIA_CHANGE from drivers on close(2) Changed our ordering on TEST UNIT READY commands meaning that SATA drives connected to an mpt2sas now suspend and refuse to wake (because the mpt2sas SATL sees the suspend *before* the drives get awoken by the next ATA command) resulting in lots of failed commands. The standard is completely nuts forcing this inconsistent behaviour, but we have to work around it. The fix for this is twofold: 1. Set the allow_restart flag so we wake the drive when we see it has been suspended 2. Return all TEST UNIT READY status directly to the mid layer without any further error handling which prevents us causing error handling which may offline the device just because of a media check TUR. Reported-by: Matthias Prager <linux@matthiasprager.de> Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20[SCSI] cleanup setting task state in scsi_error_handler()Dan Williams1-3/+1
A quick reading of scsi_error_handler() one could come away with the impression that it does its wakeup event check while the task state is TASK_RUNNING. In fact it sets TASK_INTERRUPTIBLE at the bottom of the loop, but that is ~50 lines down. Just set TASK_INTERRUPTIBLE at the top of loop and be done. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20[SCSI] fix eh wakeup (scsi_schedule_eh vs scsi_restart_operations)Dan Williams1-0/+14
Rapid ata hotplug on a libsas controller results in cases where libsas is waiting indefinitely on eh to perform an ata probe. A race exists between scsi_schedule_eh() and scsi_restart_operations() in the case when scsi_restart_operations() issues i/o to other devices in the sas domain. When this happens the host state transitions from SHOST_RECOVERY (set by scsi_schedule_eh) back to SHOST_RUNNING and ->host_busy is non-zero so we put the eh thread to sleep even though ->host_eh_scheduled is active. Before putting the error handler to sleep we need to check if the host_state needs to return to SHOST_RECOVERY for another trip through eh. Since i/o that is released by scsi_restart_operations has been blocked for at least one eh cycle, this implementation allows those i/o's to run before another eh cycle starts to discourage hung task timeouts. Cc: <stable@vger.kernel.org> Reported-by: Tom Jackson <thomas.p.jackson@intel.com> Tested-by: Tom Jackson <thomas.p.jackson@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-05-23Merge branch 'for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial updates from Jiri Kosina: "As usual, it's mostly typo fixes, redundant code elimination and some documentation updates." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (57 commits) edac, mips: don't change code that has been removed in edac/mips tree xtensa: Change mail addresses of Hannes Weiner and Oskar Schirmer lib: Change mail address of Oskar Schirmer net: Change mail address of Oskar Schirmer arm/m68k: Change mail address of Sebastian Hess i2c: Change mail address of Oskar Schirmer net: Fix tcp_build_and_update_options comment in struct tcp_sock atomic64_32.h: fix parameter naming mismatch Kconfig: replace "--- help ---" with "---help---" c2port: fix bogus Kconfig "default no" edac: Fix spelling errors. qla1280: Remove redundant NULL check before release_firmware() call remoteproc: remove redundant NULL check before release_firmware() qla2xxx: Remove redundant NULL check before release_firmware() call. aic94xx: Get rid of redundant NULL check before release_firmware() call tehuti: delete redundant NULL check before release_firmware() qlogic: get rid of a redundant test for NULL before call to release_firmware() bna: remove redundant NULL test before release_firmware() tg3: remove redundant NULL test before release_firmware() call typhoon: get rid of redundant conditional before all to release_firmware() ...
2012-04-16scsi: fix comment spelling fix recory->recoverySantosh Y1-3/+3
Signed-off-by: Santosh Y <santoshsy@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-04-15SCSI: Fix error handling when no ULD is attachedMartin K. Petersen1-1/+1
Commit 18a4d0a22ed6 ("[SCSI] Handle disk devices which can not process medium access commands") introduced a bug in which we would attempt to dereference the scsi driver even when the device had no ULD attached. Ensure that a driver is registered and make the driver accessor function more resilient to errors during device discovery. Reported-by: Elric Fu <elricfu1@gmail.com> Reported-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-19[SCSI] Handle disk devices which can not process medium access commandsMartin K. Petersen1-3/+9
We have experienced several devices which fail in a fashion we do not currently handle gracefully in SCSI. After a failure these devices will respond to the SCSI primary command set (INQUIRY, TEST UNIT READY, etc.) but any command accessing the storage medium will time out. The following patch adds an callback that can be used by upper level drivers to inspect the results of an error handling command. This in turn has been used to implement additional checking in the SCSI disk driver. If a medium access command fails twice but TEST UNIT READY succeeds both times in the subsequent error handling we will offline the device. The maximum number of failed commands required to take a device offline can be tweaked in sysfs. Also add a new error flag to scsi_debug which allows this scenario to be easily reproduced. [jejb: fix up integer parsing to use kstrtouint] Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19[SCSI] scsi_error: classify some ILLEGAL_REQUEST sense as a permanent ↵Mike Snitzer1-0/+8
TARGET_ERROR Permanent target failures are non-retryable and should be classified as TARGET_ERROR; otherwise dm-multipath will retry an IO request that will always fail at the target. A SCSI command that fails with ILLEGAL_REQUEST sense and Additional sense 0x20, 0x21, 0x24 or 0x26 represents a permanent TARGET_ERROR. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19[SCSI] fix the new host byte settings (DID_TARGET_FAILURE and DID_NEXUS_FAILURE)Moger, Babu1-2/+2
This patch fixes the host byte settings DID_TARGET_FAILURE and DID_NEXUS_FAILURE. The function __scsi_error_from_host_byte, tries to reset the host byte to DID_OK. But that does not happen because of the OR operation. Here is the flow. scsi_softirq_done-> scsi_decide_disposition -> __scsi_error_from_host_byte Let's take an example with DID_NEXUS_FAILURE. In scsi_decide_disposition, result will be set as DID_NEXUS_FAILURE (=0x11). Then in __scsi_error_from_host_byte, when we do OR with DID_OK. Purpose is to reset it back to DID_OK. But that does not happen. This patch fixes this issue. Signed-off-by: Babu Moger <babu.moger@netapp.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-01-09[SCSI] add flag to skip the runtime PM calls on the hostLin Ming1-2/+3
With previous change, now the ata port runtime suspend will happen as: disk suspend --> scsi target suspend --> scsi host suspend --> ata port suspend ata port(parent device) suspend need to schedule scsi EH which will resume scsi host(child device). Then the child device resume will in turn make parent device resume first. This is kind of recursive. This patch adds a new flag Scsi_Host::eh_noresume. ata port will set this flag to skip the runtime PM calls on scsi host. Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2011-08-27[SCSI] Fix out of spec CD-ROM problem with media changeTARUISI Hiroaki1-2/+10
Some CD-ROMs fail to report a media change correctly. The specific one for this patch simply fails to respond to commands, then gives a UNIT ATTENTION after being reset which returns ASC/ASCQ 28/00. This is out of spec behaviour, but add a check in the eat CC/UA on reset path to catch this case so the CD-ROM will function somewhat properly. [jejb: fixed up white space and accepted without signoff] Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-05-24[SCSI] Reduce error recovery time by reducing use of TURsDavid Jeffery1-20/+67
In error recovery, most scsi error recovery stages will send a TUR command for every bad command when a driver's error handler reports success. When several bad commands to the same device, this results in a device being probed multiple times. This becomes very problematic if the device or connection is in a state where the device still doesn't respond to commands even after a recovery function returns success. The error handler must wait for the test commands to time out. The time waiting for the redundant commands can drastically lengthen error recovery. This patch alters the scsi mid-layer's error routines to send test commands once per device instead of once per bad command. This can drastically lower error recovery time. [jejb: fixed up whitespace and formatting] Signed-of-by: David Jeffery <djeffery@redhat.com> Signed-off-by: James Bottomley <jbottomley@parallels.com>
2011-04-16[SCSI] Log thin provisioning threshold eventShyam Iyer1-0/+6
At least log the message that we received a THIN PROVISIONING SOFT THRESHOLD REACHED Unit Attention. Also added it to unit attention decodes. Signed-off-by: Shyam Iyer <shyam_iyer@dell.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-03-22Reduce sequential pointer derefs in scsi_error.c and reduce size as wellJesper Juhl1-45/+49
This patch reduces the number of sequential pointer derefs in drivers/scsi/scsi_error.c This has been submitted a number of times over a couple of years. I believe this version adresses all comments it has gathered over time. Please apply or reject with a reason. The benefits are: - makes the code easier to read. Lots of sequential derefs of the same pointers is not easy on the eye. - theoretically at least, just dereferencing the pointers once can allow the compiler to generally slightly faster code, so in theory this could also be a micro speed optimization. - reduces size of object file (tiny effect: on x86-64, in at least one configuration, the text size decreased from 9439 bytes to 9400) - removes some pointless (mostly trailing) whitespace. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-12[SCSI] Add detailed SCSI I/O errorsHannes Reinecke1-7/+17
Instead of just passing 'EIO' for any I/O error we should be notifying the upper layers with more details about the cause of this error. Update the possible I/O errors to: - ENOLINK: Link failure between host and target - EIO: Retryable I/O error - EREMOTEIO: Non-retryable I/O error - EBADE: I/O error restricted to the I_T_L nexus 'Retryable' in this context means that an I/O error _might_ be restricted to the I_T_L nexus (vulgo: path), so retrying on another nexus / path might succeed. 'Non-retryable' in general refers to a target failure, so this error will always be generated regardless of the I_T_L nexus it was send on. I/O errors restricted to the I_T_L nexus might be retried on another nexus / path, but they should _not_ be queued if no paths are available. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-21[SCSI] fix id computation in scsi_eh_target_reset()James Bottomley1-36/+25
The current code in scsi_eh_target_reset() has an off by one error that actually sends spurious extra resets. Since there's no real need to reset the targets in numerical order, simply chunk up the command recovery list doing target resets and pulling matching targets out of the list (that also makes the loop O(N) instead of O(N^2). [mike christie found and fixed a list_splice -> list_splice_init problem] Reported-by: Hillf Danton<dhillf@gmail.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-09[SCSI] Eliminate error handler overload of the SCSI serial numberJames Bottomley1-24/+2
The error handler is using the test cmd->serial_number == 0 in the abort routines to signal that the command to be aborted has already completed normally. This design was to close a race window in the original error handler where a command could go through the normal completion routines after it timed out but before error handling was started. Mike Anderson pointed out that when we converted our timeout and softirq completions, we picked up atomicity here because the block layer now mediates this with the REQ_ATOM_COMPLETE flag and guarantees that *either* the command times out or our done routine is called, but ensures we can't get both occurring. That makes the serial number zero check redundant and it can be removed. Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-11-17SCSI host lock push-downJeff Garzik1-4/+2
Move the mid-layer's ->queuecommand() invocation from being locked with the host lock to being unlocked to facilitate speeding up the critical path for drivers who don't need this lock taken anyway. The patch below presents a simple SCSI host lock push-down as an equivalent transformation. No locking or other behavior should change with this patch. All existing bugs and locking orders are preserved. Additionally, add one parameter to queuecommand, struct Scsi_Host * and remove one parameter from queuecommand, void (*done)(struct scsi_cmnd *) Scsi_Host* is a convenient pointer that most host drivers need anyway, and 'done' is redundant to struct scsi_cmnd->scsi_done. Minimal code disturbance was attempted with this change. Most drivers needed only two one-line modifications for their host lock push-down. Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Acked-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-10block: remove REQ_HARDBARRIERChristoph Hellwig1-13/+5
REQ_HARDBARRIER is dead now, so remove the leftovers. What's left at this point is: - various checks inside the block layer. - sanity checks in bio based drivers. - now unused bio_empty_barrier helper. - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while, but Xen really needs to sort out it's barrier situaton. - setting of ordered tags in uas - dead code copied from old scsi drivers. - scsi different retry for barriers - it's dead and should have been removed when flushes were converted to FS requests. - blktrace handling of barriers - removed. Someone who knows blktrace better should add support for REQ_FLUSH and REQ_FUA, though. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds1-4/+7
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (28 commits) [SCSI] qla4xxx: fix compilation warning [SCSI] make error handling more robust in the face of reservations [SCSI] tgt: fix warning [SCSI] drivers/message/fusion: Adjust confusing if indentation [SCSI] Return NEEDS_RETRY for eh commands with status BUSY [SCSI] ibmvfc: Driver version 1.0.9 [SCSI] ibmvfc: Fix terminate_rport_io [SCSI] ibmvfc: Fix rport add/delete race resulting in oops [SCSI] lpfc 8.3.16: Change LPFC driver version to 8.3.16 [SCSI] lpfc 8.3.16: FCoE Discovery and Failover Fixes [SCSI] lpfc 8.3.16: SLI Additions, updates, and code cleanup [SCSI] pm8001: introduce missing kfree [SCSI] qla4xxx: Update driver version to 5.02.00-k3 [SCSI] qla4xxx: Added AER support for ISP82xx [SCSI] qla4xxx: Handle outstanding mbx cmds on hung f/w scenarios [SCSI] qla4xxx: updated mbx_sys_info struct to sync with FW 4.6.x [SCSI] qla4xxx: clear AF_DPC_SCHEDULED flage when exit from do_dpc [SCSI] qla4xxx: Stop firmware before doing init firmware. [SCSI] qla4xxx: Use the correct request queue. [SCSI] qla4xxx: set correct value in sess->recovery_tmo ...
2010-08-11[SCSI] make error handling more robust in the face of reservationsJames Bottomley1-4/+6
commit 5f91bb050ecc4ff1d8d3d07edbe550c8f431c5e1 Author: Michael Reed <mdr@sgi.com> Date: Mon Aug 10 11:59:28 2009 -0500 [SCSI] reservation conflict after timeout causes device to be taken offline Flipped us from always returning failed to always returning success in the name of fixing the problem where reservation conflict returns from test unit ready cause the device always to be taken offline. Unfortuantely, it also introduced a problem whereby for commands other than test unit ready, the eh dispatcher thinks they succeeded when reservation conflict is returned, whereas in reality they failed. Fix this by only returning success for the test unit ready case. Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-08-11[SCSI] Return NEEDS_RETRY for eh commands with status BUSYHannes Reinecke1-0/+1
When the transport is busy and we're sending an EH command drivers occasionally return 'BUSY'. As this in most cases is the TUR command sent as part of the error recovery this is a sure way to make the error recovery escalate. Returning 'NEEDS_RETRY' here will just retry the TUR command and eventually abort the original command, thus making error handling far smoother. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-08-11Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds1-5/+7
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits) block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n xen-blkfront: fix missing out label blkdev: fix blkdev_issue_zeroout return value block: update request stacking methods to support discards block: fix missing export of blk_types.h writeback: fix bad _bh spinlock nesting drbd: revert "delay probes", feature is being re-implemented differently drbd: Initialize all members of sync_conf to their defaults [Bugz 315] drbd: Disable delay probes for the upcomming release writeback: cleanup bdi_register writeback: add new tracepoints writeback: remove unnecessary init_timer call writeback: optimize periodic bdi thread wakeups writeback: prevent unnecessary bdi threads wakeups writeback: move bdi threads exiting logic to the forker thread writeback: restructure bdi forker loop a little writeback: move last_active to bdi writeback: do not remove bdi from bdi_list writeback: simplify bdi code a little writeback: do not lose wake-ups in bdi threads ... Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and drivers/scsi/scsi_error.c as per Jens.
2010-08-07scsi: use REQ_TYPE_FS for flush requestFUJITA Tomonori1-15/+4
scsi-ml uses REQ_TYPE_BLOCK_PC for flush requests from file systems. The definition of REQ_TYPE_BLOCK_PC is that we don't retry requests even when we can (e.g. UNIT ATTENTION) and we send the response to the callers (then the callers can decide what they want). We need a workaround such as the commit 77a4229719e511a0d38d9c355317ae1469adeb54 to retry BLOCK_PC flush requests. We will need the similar workaround for discard requests too since SCSI-ml handle them as BLOCK_PC internally. This uses REQ_TYPE_FS for flush requests from file systems instead of REQ_TYPE_BLOCK_PC. scsi-ml retries only REQ_TYPE_FS requests that have data to transfer when we can retry them (e.g. UNIT_ATTENTION). However, we also need to retry REQ_TYPE_FS requests without data because the callers don't. This also changes scsi_check_sense() to retry all the REQ_TYPE_FS requests when appropriate. Thanks to scsi_noretry_cmd(), REQ_TYPE_BLOCK_PC requests don't be retried as before. Note that basically, this reverts the commit 77a4229719e511a0d38d9c355317ae1469adeb54 since now we use REQ_TYPE_FS for flush requests. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07block: remove wrappers for request type/flagsChristoph Hellwig1-5/+5
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in struct requests. This allows much easier grepping for different request types instead of unwinding through macros. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-28[SCSI] implement runtime Power ManagementAlan Stern1-1/+15
This patch (as1398b) adds runtime PM support to the SCSI layer. Only the machanism is provided; use of it is up to the various high-level drivers, and the patch doesn't change any of them. Except for sg -- the patch expicitly prevents a device from being runtime-suspended while its sg device file is open. The implementation is simplistic. In general, hosts and targets are automatically suspended when all their children are asleep, but for them the runtime-suspend code doesn't actually do anything. (A host's runtime PM status is propagated up the device tree, though, so a runtime-PM-aware lower-level driver could power down the host adapter hardware at the appropriate times.) There are comments indicating where a transport class might be notified or some other hooks added. LUNs are runtime-suspended by calling the drivers' existing suspend handlers (and likewise for runtime-resume). Somewhat arbitrarily, the implementation delays for 100 ms before suspending an eligible LUN. This is because there typically are occasions during bootup when the same device file is opened and closed several times in quick succession. The way this all works is that the SCSI core increments a device's PM-usage count when it is registered. If a high-level driver does nothing then the device will not be eligible for runtime-suspend because of the elevated usage count. If a high-level driver wants to use runtime PM then it can call scsi_autopm_put_device() in its probe routine to decrement the usage count and scsi_autopm_get_device() in its remove routine to restore the original count. Hosts, targets, and LUNs are not suspended while they are being probed or removed, or while the error handler is running. In fact, a fairly large part of the patch consists of code to make sure that things aren't suspended at such times. [jejb: fix up compile issues in PM config variations] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-27[SCSI] Log msg when getting Unit AttentionMike Christie1-0/+13
If the user accidentally changes LUN mappings or it occurs due to a bug, then it can cause data corruption that can take months and months to track down. This patch adds a log message when getting REPORT_LUNS_DATA_CHANGED and it adds a generic message for other Unit Attentions with asc == 0x3f. We are working on adding support for handling of these errors, but I think until then we should at least log a message so tracking down problems as a result of one of these changes is a little easier. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-05-18[SCSI] Merge scsi-misc-2.6 into scsi-rc-fixes-2.6James Bottomley1-5/+14
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-05-05[SCSI] Retry commands with UNIT_ATTENTION sense codes to fix ext3/ext4 I/O errorJames Bottomley1-1/+14
There's nastyness in the way we currently handle barriers (and discards): They're effectively filesystem commands, but they get processed as BLOCK_PC commands. Unfortunately BLOCK_PC commands are taken by SCSI to be SG_IO commands and the issuer expects to see and handle any returned errors, however trivial. This leads to a huge problem, because the block layer doesn't expect this to happen and any trivially retryable error on a barrier causes an immediate I/O error to the filesystem. The only real way to hack around this is to take the usual class of offending errors (unit attentions) and make them all retryable in the case of a REQ_HARDBARRIER. A correct fix would involve a rework of the entire block and SCSI submit system, and so is out of scope for a quick fix. Cc: Hannes Reinecke <hare@suse.de> Cc: Stable Tree <stable@kernel.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-04-30[SCSI] add scsi trace core functions and put trace pointsKei Tokunaga1-0/+4
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com> Signed-off-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>