linux/include/scsi
Boaz Harrosh 5d0961fd1f [SCSI] libosd: Fix blk_put_request locking again
So libosd has decided to sacrifice some code simplicity for the sake of
a clean API. One of these things is the possibility for users to call
osd_end_request, in any condition at any state. This opens up some
problems with calling blk_put_request when out-side of the completion
callback but calling __blk_put_request when detecting a from-completion
state.

The current hack was working just fine until exofs decided to operate on
all devices in parallel and wait for the sum of the requests, before
deallocating all osd-requests at once. There are two new possible cases
1. All request in a group are deallocated as part of the last request's
   async-done, request_queue is locked.
2. All request in a group where executed asynchronously, but
   de-allocation was delayed to after the async-done, in the context of
   another thread. Async execution but request_queue is not locked.

The solution I chose was to separate the deallocation of the osd_request
which has the information users need, from the deallocation of the
internal(2) requests which impose the locking problem. The internal
block-requests are freed unconditionally inside the async-done-callback,
when we know the queue is always locked. If at osd_end_request time we
still have a bock-request, then we know it did not come from within an
async-done-callback and we can call the regular blk_put_request.

The internal requests were used for carrying error information after
execution. This information is now copied to osd_request members for
later analysis by user code.

The external API and behaviour was unchanged, except now it really
supports what was previously advertised.

Reported-by: Vineet Agarwal <checkout.vineet@gmail.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-10 08:54:17 -06:00
..
fc [SCSI] libfc: Add target reset flag to FCP header file 2009-12-04 12:02:00 -06:00
fc_encode.h [SCSI] libfc: register FC4 features with the FC switch 2009-12-04 12:01:20 -06:00
fc_frame.h [SCSI] fcoe, libfc: use single frame allocation API 2009-12-04 12:01:09 -06:00
iscsi_if.h [SCSI] libiscsi: add warm target reset tmf support 2009-12-04 12:01:36 -06:00
iscsi_proto.h [SCSI] libiscsi: Check TMF state before sending PDU 2009-12-04 12:01:36 -06:00
Kbuild [SCSI] libfc: Export FC headers 2009-12-04 12:01:05 -06:00
libfc.h [SCSI] fcoe, libfc: add get_lesb() to allow LLD to fill the link error status block (LESB) 2009-12-04 12:01:58 -06:00
libfcoe.h [SCSI] libfcoe: add checking disable flag in FIP_FKA_ADV 2009-12-04 12:01:55 -06:00
libiscsi_tcp.h [SCSI] iscsi_tcp: make padbuf non-static 2009-01-13 10:41:34 -06:00
libiscsi.h [SCSI] libiscsi: add warm target reset tmf support 2009-12-04 12:01:36 -06:00
libsas.h [SCSI] modify change_queue_depth to take in reason why it is being called 2009-12-04 12:00:41 -06:00
libsrp.h
osd_attributes.h [SCSI] libosd: OSD2r05: Attribute definitions 2009-06-10 08:54:07 -05:00
osd_initiator.h [SCSI] libosd: Fix blk_put_request locking again 2009-12-10 08:54:17 -06:00
osd_protocol.h [SCSI] osd_protocol.h: Add missing #include 2009-12-04 12:01:48 -06:00
osd_sec.h [SCSI] libosd: OSDv1 Headers 2009-03-12 12:58:06 -05:00
osd_sense.h [SCSI] libosd: osd_sense: OSD_CFO_PERMISSIONS 2009-12-04 12:01:44 -06:00
osd_types.h [SCSI] libosd: OSDv1 Headers 2009-03-12 12:58:06 -05:00
sas_ata.h
sas.h
scsi_bsg_fc.h [SCSI] FC Pass Thru support 2009-06-12 14:20:05 -05:00
scsi_cmnd.h [SCSI] Deprecate SCSI_PROT_*_CONVERT operations 2009-10-02 09:46:25 -05:00
scsi_dbg.h
scsi_device.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2009-12-09 19:42:25 -08:00
scsi_devinfo.h
scsi_dh.h [SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronous 2009-12-04 12:00:46 -06:00
scsi_driver.h sd, sr: fix Driver 'sd' needs updating message 2009-06-21 12:01:27 -05:00
scsi_eh.h [SCSI] scsi_eh_prep_cmnd should save scmd->underflow 2008-07-26 15:14:56 -04:00
scsi_host.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2009-12-09 19:42:25 -08:00
scsi_ioctl.h [PATCH] don't mess with file in scsi_nonblockable_ioctl() 2008-10-21 07:47:28 -04:00
scsi_netlink_fc.h
scsi_netlink.h [SCSI] scsi_netlink: Add transport and LLD recieve and event support 2008-10-03 11:46:13 -05:00
scsi_scan.h PM/Hibernate: Wait for SCSI devices scan to complete during resume 2009-04-13 11:37:07 -07:00
scsi_tcq.h scsi: make sure that scsi_init_shared_tag_map() doesn't overwrite existing map 2008-10-27 19:25:30 +01:00
scsi_tgt_if.h
scsi_tgt.h
scsi_transport_fc.h [SCSI] scsi_transport_fc: Introduce helper function for blocking scsi_eh 2009-12-04 12:00:52 -06:00
scsi_transport_iscsi.h [SCSI] iscsi class: Add new NETLINK_ISCSI messages for cnic/bnx2i driver. 2009-06-09 10:22:35 -05:00
scsi_transport_sas.h
scsi_transport_spi.h [SCSI] aic79xx: make driver respect nvram for IU and QAS settings 2009-06-15 10:09:35 -05:00
scsi_transport_srp.h
scsi_transport.h block: unify request timeout handling 2008-10-09 08:56:13 +02:00
scsi.h [SCSI] scsi: Add missing command definitions 2009-12-04 12:00:15 -06:00
scsicam.h
sg.h
srp.h