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author | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-09-13 02:30:46 -0700 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-09-24 23:17:07 -0700 |
commit | 3ccd6e83df8a0d4a664edeecc453c4fa046395fb (patch) | |
tree | 1c8e69d2f81bb214c545b663508364247fb699ea /drivers/target/target_core_device.c | |
parent | 9fd60088ffed7573c2d409ddc63a2150a5edd5d8 (diff) | |
download | linux-stable-3ccd6e83df8a0d4a664edeecc453c4fa046395fb.tar.gz linux-stable-3ccd6e83df8a0d4a664edeecc453c4fa046395fb.tar.bz2 linux-stable-3ccd6e83df8a0d4a664edeecc453c4fa046395fb.zip |
target: Fix PR registration + APTPL RCU conversion regression
This patch fixes a v4.2+ regression introduced by commit 79dc9c9e86
where lookup of t10_pr_registration->pr_reg_deve and associated
->pr_kref get was missing from __core_scsi3_do_alloc_registration(),
which is responsible for setting DEF_PR_REG_ACTIVE.
This would result in REGISTER operations completing successfully,
but subsequent core_scsi3_pr_seq_non_holder() checking would fail
with !DEF_PR_REG_ACTIVE -> RESERVATION CONFLICT status.
Update __core_scsi3_add_registration() to drop ->pr_kref reference
after registration and any optional ALL_TG_PT=1 processing has
completed. Update core_scsi3_decode_spec_i_port() to release
the new parent local_pr_reg->pr_kref as well.
Also, update __core_scsi3_check_aptpl_registration() to perform
the same target_nacl_find_deve() lookup + ->pr_kref get, now that
__core_scsi3_add_registration() expects to drop the reference.
Finally, since there are cases when se_dev_entry->se_lun_acl can
still be dereferenced in core_scsi3_lunacl_undepend_item() while
holding ->pr_kref, go ahead and move explicit rcu_assign_pointer()
NULL assignments within core_disable_device_list_for_node() until
after orig->pr_comp finishes.
Reported-by: Scott L. Lykens <scott@lykens.org>
Tested-by: Scott L. Lykens <scott@lykens.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Lee Duncan <lduncan@suse.com>
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_device.c')
-rw-r--r-- | drivers/target/target_core_device.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index dcc424ac35d4..abf20763b0b6 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -427,8 +427,6 @@ void core_disable_device_list_for_node( hlist_del_rcu(&orig->link); clear_bit(DEF_PR_REG_ACTIVE, &orig->deve_flags); - rcu_assign_pointer(orig->se_lun, NULL); - rcu_assign_pointer(orig->se_lun_acl, NULL); orig->lun_flags = 0; orig->creation_time = 0; orig->attach_count--; @@ -439,6 +437,9 @@ void core_disable_device_list_for_node( kref_put(&orig->pr_kref, target_pr_kref_release); wait_for_completion(&orig->pr_comp); + rcu_assign_pointer(orig->se_lun, NULL); + rcu_assign_pointer(orig->se_lun_acl, NULL); + kfree_rcu(orig, rcu_head); core_scsi3_free_pr_reg_from_nacl(dev, nacl); |