linux.git/drivers/target/target_core_device.c, branch v6.1

scsi: target: core: UA on all LUNs after reset

2022-10-01T09:06:53+00:00

Allocate UNIT ATTENTION "BUS DEVICE RESET OCCURRED" on all LUNs on all
target ports of the device upon reception of TMF LUN RESET.

This change passes libiscsi test SCSI.MultipathIO.Reset.

Link: https://lore.kernel.org/r/20220913163602.20597-1-d.bogdanov@yadro.com
Signed-off-by: Dmitry Bogdanov 
Signed-off-by: Martin K. Petersen

scsi: target: core: De-RCU of se_lun and se_lun acl

2022-08-01T23:36:02+00:00

se_lun and se_lun_acl are immutable pointers of struct se_dev_entry.
Remove RCU usage for access to those pointers.

Link: https://lore.kernel.org/r/20220727214125.19647-3-d.bogdanov@yadro.com
Reviewed-by: Mike Christie 
Signed-off-by: Dmitry Bogdanov 
Signed-off-by: Martin K. Petersen

scsi: target: core: Fix race during ACL removal

2022-08-01T23:36:02+00:00

Under huge load there is a possibility of race condition in updating
se_dev_entry object in ACL removal procedure:

 NIP [c0080000154093d0] transport_lookup_cmd_lun+0x1f8/0x3d0 [target_core_mod]
 LR [c00800001542ab34] target_submit_cmd_map_sgls+0x11c/0x300 [target_core_mod]
 Call Trace:
   target_submit_cmd_map_sgls+0x11c/0x300 [target_core_mod]
   target_submit_cmd+0x44/0x60 [target_core_mod]
   tcm_qla2xxx_handle_cmd+0x88/0xe0 [tcm_qla2xxx]
   qlt_do_work+0x2e4/0x3d0 [qla2xxx]
   process_one_work+0x298/0x5c

Despite usage of RCU primitives with deve->se_lun pointer, it has not
become dereference-safe because deve->se_lun is updated and not
synchronized with a reader. That change might be in a release function
called by synchronize_rcu(). But, in fact, there is no point in setting
that pointer to NULL for deleting deve. All access to deve->se_lun is
already under rcu_read_lock. And either deve->se_lun is always valid or
deve is not valid itself and will not be found in the list_for_*.  The same
applicable for deve->se_lun_acl too.  So a better solution is to remove
that NULLing.

Link: https://lore.kernel.org/r/20220727214125.19647-2-d.bogdanov@yadro.com
Reviewed-by: Mike Christie 
Signed-off-by: Dmitry Bogdanov 
Signed-off-by: Martin K. Petersen

scsi: target: Add callout to configure UNMAP settings

2022-07-07T20:53:52+00:00

Add a callout to configure a backend's UNMAP settings. This will be used to
allow userspace to configure UNMAP after the initial device setup, similar
to how we can set up the other attributes post device configuration.

Link: https://lore.kernel.org/r/20220628200230.15052-3-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

block: add a bdev_discard_granularity helper

2022-04-18T01:49:59+00:00

Abstract away implementation details from file systems by providing a
block_device based helper to retrieve the discard granularity.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Acked-by: Christoph Böhmwalder  [drbd]
Acked-by: Ryusuke Konishi 
Acked-by: David Sterba  [btrfs]
Link: https://lore.kernel.org/r/20220415045258.199825-26-hch@lst.de
Signed-off-by: Jens Axboe

block: remove QUEUE_FLAG_DISCARD

2022-04-18T01:49:59+00:00

Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Acked-by: Christoph Böhmwalder  [drbd]
Acked-by: Jan Höppner  [s390]
Acked-by: Coly Li  [bcache]
Acked-by: David Sterba  [btrfs]
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe

block: add a bdev_max_discard_sectors helper

2022-04-18T01:49:59+00:00

Add a helper to query the number of sectors support per each discard bio
based on the block device and use this helper to stop various places from
poking into the request_queue to see if discard is supported and if so how
much.  This mirrors what is done e.g. for write zeroes as well.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Acked-by: Christoph Böhmwalder  [drbd]
Acked-by: Coly Li  [bcache]
Acked-by: David Sterba  [btrfs]
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-24-hch@lst.de
Signed-off-by: Jens Axboe

target: fix discard alignment on partitions

2022-04-18T01:49:58+00:00

Use the proper bdev_discard_alignment helper that accounts for partition
offsets.

Fixes: c66ac9db8d4a ("[SCSI] target: Add LIO target core v4.0.0-rc6")
Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-4-hch@lst.de
Signed-off-by: Jens Axboe

target: pass a block_device to target_configure_unmap_from_queue

2022-04-18T01:49:58+00:00

The SCSI target drivers is a consumer of the block layer and shoul
d generally work on struct block_device.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-3-hch@lst.de
Signed-off-by: Jens Axboe

target: remove an incorrect unmap zeroes data deduction

2022-04-18T01:49:58+00:00

For block devices, the SCSI target drivers implements UNMAP as calls to
blkdev_issue_discard, which does not guarantee zeroing just because
Write Zeroes is supported.

Note that this does not affect the file backed path which uses
fallocate to punch holes.

Fixes: 2237498f0b5c ("target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout")
Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-2-hch@lst.de
Signed-off-by: Jens Axboe