linux-stable.git/drivers/target, branch linux-5.5.y

scsi: target: fix hang when multiple threads try to destroy the same iscsi session

2020-04-21T07:06:45+00:00

[ Upstream commit 57c46e9f33da530a2485fa01aa27b6d18c28c796 ]

A number of hangs have been reported against the target driver; they are
due to the fact that multiple threads may try to destroy the iscsi session
at the same time. This may be reproduced for example when a "targetcli
iscsi/iqn.../tpg1 disable" command is executed while a logout operation is
underway.

When this happens, two or more threads may end up sleeping and waiting for
iscsit_close_connection() to execute "complete(session_wait_comp)".  Only
one of the threads will wake up and proceed to destroy the session
structure, the remaining threads will hang forever.

Note that if the blocked threads are somehow forced to wake up with
complete_all(), they will try to free the same iscsi session structure
destroyed by the first thread, causing double frees, memory corruptions
etc...

With this patch, the threads that want to destroy the iscsi session will
increase the session refcount and will set the "session_close" flag to 1;
then they wait for the driver to close the remaining active connections.
When the last connection is closed, iscsit_close_connection() will wake up
all the threads and will wait for the session's refcount to reach zero;
when this happens, iscsit_close_connection() will destroy the session
structure because no one is referencing it anymore.

 INFO: task targetcli:5971 blocked for more than 120 seconds.
       Tainted: P           OE    4.15.0-72-generic #81~16.04.1
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 targetcli       D    0  5971      1 0x00000080
 Call Trace:
  __schedule+0x3d6/0x8b0
  ? vprintk_func+0x44/0xe0
  schedule+0x36/0x80
  schedule_timeout+0x1db/0x370
  ? __dynamic_pr_debug+0x8a/0xb0
  wait_for_completion+0xb4/0x140
  ? wake_up_q+0x70/0x70
  iscsit_free_session+0x13d/0x1a0 [iscsi_target_mod]
  iscsit_release_sessions_for_tpg+0x16b/0x1e0 [iscsi_target_mod]
  iscsit_tpg_disable_portal_group+0xca/0x1c0 [iscsi_target_mod]
  lio_target_tpg_enable_store+0x66/0xe0 [iscsi_target_mod]
  configfs_write_file+0xb9/0x120
  __vfs_write+0x1b/0x40
  vfs_write+0xb8/0x1b0
  SyS_write+0x5c/0xe0
  do_syscall_64+0x73/0x130
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Link: https://lore.kernel.org/r/20200313170656.9716-3-mlombard@redhat.com
Reported-by: Matt Coleman 
Tested-by: Matt Coleman 
Tested-by: Rahul Kundu 
Signed-off-by: Maurizio Lombardi 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: remove boilerplate code

2020-04-21T07:06:45+00:00

[ Upstream commit e49a7d994379278d3353d7ffc7994672752fb0ad ]

iscsit_free_session() is equivalent to iscsit_stop_session() followed by a
call to iscsit_close_session().

Link: https://lore.kernel.org/r/20200313170656.9716-2-mlombard@redhat.com
Tested-by: Rahul Kundu 
Signed-off-by: Maurizio Lombardi 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: Revert "target: iscsi: Wait for all commands to finish before freeing a session"

2020-02-28T16:23:42+00:00

commit 807b9515b7d044cf77df31f1af9d842a76ecd5cb upstream.

Since commit e9d3009cb936 introduced a regression and since the fix for
that regression was not perfect, revert this commit.

Link: https://marc.info/?l=target-devel&m=158157054906195
Cc: Rahul Kundu 
Cc: Mike Marciniszyn 
Cc: Sagi Grimberg 
Reported-by: Dakshaja Uppalapati 
Fixes: e9d3009cb936 ("scsi: target: iscsi: Wait for all commands to finish before freeing a session")
Signed-off-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Greg Kroah-Hartman

scsi: Revert "RDMA/isert: Fix a recently introduced regression related to logout"

2020-02-28T16:23:42+00:00

commit 76261ada16dcc3be610396a46d35acc3efbda682 upstream.

Since commit 04060db41178 introduces soft lockups when toggling network
interfaces, revert it.

Link: https://marc.info/?l=target-devel&m=158157054906196
Cc: Rahul Kundu 
Cc: Mike Marciniszyn 
Cc: Sagi Grimberg 
Reported-by: Dakshaja Uppalapati 
Fixes: 04060db41178 ("scsi: RDMA/isert: Fix a recently introduced regression related to logout")
Signed-off-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Greg Kroah-Hartman

scsi: Revert "target/core: Inline transport_lun_remove_cmd()"

2020-02-28T16:23:33+00:00

commit c14335ebb92a98646ddbf447e6cacc66de5269ad upstream.

Commit 83f85b8ec305 postponed the percpu_ref_put(&se_cmd->se_lun->lun_ref)
call from command completion to the time when the final command reference
is dropped. That approach is not compatible with the iSCSI target driver
because the iSCSI target driver keeps the command with the highest stat_sn
after it has completed until the next command is received (see also
iscsit_ack_from_expstatsn()). Fix this regression by reverting commit
83f85b8ec305.

Fixes: 83f85b8ec305 ("scsi: target/core: Inline transport_lun_remove_cmd()")
Cc: Pavel Zakharov 
Cc: Mike Christie 
Cc: 
Link: https://lore.kernel.org/r/20200210051202.12934-1-bvanassche@acm.org
Reported-by: Pavel Zakharov 
Signed-off-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2020-01-26T18:39:09+00:00

Pull SCSI fixes from James Bottomley:
 "Two last minute fixes, both in drivers.

  The fnic one is a highly unlikely condition, but the RDMA one is a
  recently introduced regression that causes a kernel warning to trigger
  in every RDMA logon, which would be unsightly if it got into the final
  release"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: RDMA/isert: Fix a recently introduced regression related to logout
  scsi: fnic: do not queue commands during fwreset

scsi: RDMA/isert: Fix a recently introduced regression related to logout

2020-01-21T05:24:46+00:00

iscsit_close_connection() calls isert_wait_conn(). Due to commit
e9d3009cb936 both functions call target_wait_for_sess_cmds() although that
last function should be called only once. Fix this by removing the
target_wait_for_sess_cmds() call from isert_wait_conn() and by only calling
isert_wait_conn() after target_wait_for_sess_cmds().

Fixes: e9d3009cb936 ("scsi: target: iscsi: Wait for all commands to finish before freeing a session").
Link: https://lore.kernel.org/r/20200116044737.19507-1-bvanassche@acm.org
Reported-by: Rahul Kundu 
Signed-off-by: Bart Van Assche 
Tested-by: Mike Marciniszyn 
Acked-by: Sagi Grimberg 
Signed-off-by: Martin K. Petersen

Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2019-12-28T01:28:41+00:00

Pull SCSI fixes from James Bottomley:
 "Four fixes and one spelling update, all in drivers: two in lpfc and
  the rest in mp3sas, cxgbi and target"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: target/iblock: Fix protection error with blocks greater than 512B
  scsi: libcxgbi: fix NULL pointer dereference in cxgbi_device_destroy()
  scsi: lpfc: fix spelling mistakes of asynchronous
  scsi: lpfc: fix build failure with DEBUGFS disabled
  scsi: mpt3sas: Fix double free in attach error handling

scsi: target/iblock: Fix protection error with blocks greater than 512B

2019-12-19T23:50:34+00:00

The sector size of the block layer is 512 bytes, but integrity interval
size might be different (in case of 4K block size of the media). At the
initiator side the virtual start sector is the one that was originally
submitted by the block layer (512 bytes) for the Reftag usage. The
initiator converts the Reftag to integrity interval units and sends it to
the target. So the target virtual start sector should be calculated at
integrity interval units. prepare_fn() and complete_fn() don't remap
correctly the Reftag when using incorrect units of the virtual start
sector, which leads to the following protection error at the device:

"blk_update_request: protection error, dev sdb, sector 2048 op 0x0:(READ)
flags 0x10000 phys_seg 1 prio class 0"

To fix that, set the seed in integrity interval units.

Link: https://lore.kernel.org/r/1576078562-15240-1-git-send-email-israelr@mellanox.com
Signed-off-by: Israel Rukshin 
Reviewed-by: Max Gurtovoy 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Martin K. Petersen

treewide: Use sizeof_field() macro

2019-12-09T18:36:44+00:00

Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().

This patch is generated using following script:

EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"

git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do

	if [[ "$file" =~ $EXCLUDE_FILES ]]; then
		continue
	fi
	sed -i  -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done

Signed-off-by: Pankaj Bharadiya 
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook 
Signed-off-by: Kees Cook 
Acked-by: David Miller  # for net