linux-stable.git/drivers/target/target_core_device.c, branch linux-3.1.y

target: Convert acl_node_lock to be IRQ-disabling

2011-08-22T19:28:36+00:00

With qla2xxx, acl_node_lock is taken inside qla2xxx's hardware_lock,
which is taken in hardirq context.  This means acl_node_lock must become
an IRQ-disabling lock; in particular this fixes lockdep warnings along
the lines of

    ======================================================
    [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]

     (&(&se_tpg->acl_node_lock)->rlock){+.....}, at: [] transport_deregister_session+0x92/0x140 [target_core_mod]

    and this task is already holding:
     (&(&ha->hardware_lock)->rlock){-.-...}, at: [] qla_tgt_stop_phase1+0x57/0x2c0 [qla2xxx]
    which would create a new lock dependency:
     (&(&ha->hardware_lock)->rlock){-.-...} -> (&(&se_tpg->acl_node_lock)->rlock){+.....}

    but this new dependency connects a HARDIRQ-irq-safe lock:
     (&(&ha->hardware_lock)->rlock){-.-...}

    to a HARDIRQ-irq-unsafe lock:
     (&(&se_tpg->acl_node_lock)->rlock){+.....}

Signed-off-by: Roland Dreier 
Signed-off-by: Nicholas Bellinger

target: Fix task count > 1 handling breakage and use max_sector page alignment

2011-08-22T19:26:27+00:00

This patch addresses recent breakage with multiple se_task (task_count > 1)
operation following backend dev->se_sub_dev->se_dev_attrib.max_sectors in new
transport_allocate_data_tasks() code.  The initial bug here was a bogus
task->task_sg_nents assignment in transport_allocate_data_tasks() based on
the passed parameter, which now uses DIV_ROUND_UP(task_size, PAGE_SIZE) to
determine the proper number of per task SGL entries for the (task_count > 1)
case.

This also means we now need to enforce a PAGE_SIZE aligned max_sector count
value for this to work as expected without bringing back the pre v3.1
transport_map_mem_to_sg() logic to handle SGL offsets across multiple tasks.
So this patch adds se_dev_align_max_sectors() to round down max_sectors as
necessary to ensure this alignment via se_dev_set_default_attribs() and
se_dev_align_max_sectors() and keeps it simple for (task_count > 1)
operation.

So far this bugfix has been tested with (task_count > 1) operation
using iscsi-target and iblock backends.

Reported-by: Chris Boot 
Cc: Kiran Patil 
Cc: Andy Grover 
Cc: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger

target: Make standard INQUIRY return 'not connected' for tpg_virt_lun0

2011-08-22T19:25:35+00:00

This patch changes target_emulate_inquiry_std() to set the 'not connected'
(0x35) bit in standard INQUIRY response data when we are processing a
request to a virtual LUN=0 mapping from struct se_device *g_lun0_dev that
have been setup for us in transport_lookup_cmd_lun().

This addresses an issue where qla2xxx FC clients need to be able
to create demo-mode I_T FC Nexuses by default, but should not be
exposing the default set of TPG LUNs to all FC clients.  This includes
adding an new optional target_core_fabric_ops->tpg_check_demo_mode_login_only()
caller to allow demo_mode nexuses to skip the old default of bulding
a demo-mode MappedLUNs list via core_tpg_add_node_to_devs().

(roland: Add missing tpg_check_demo_mode_login_only check in core_dev_add_lun)

Reported-by: Roland Dreier 
Cc: Andrew Vasquez 
Signed-off-by: Nicholas Bellinger

target: Update QUEUE ALGORITHM MODIFIER control page default

2011-07-22T09:37:49+00:00

This patch adds the default 'Unrestricted reordering allowed' for SCSI
control mode page QUEUE ALGORITHM MODIFIER on a per se_device basis in
target_modesense_control() following spc4r23.  This includes a new
emuluate_rest_reord configfs attribute that currently (only) accepts
zero to signal 'Unrestricted reordering allowed' in control mode page
usage by the backend target device.

Reported-by: Roland Dreier 
Signed-off-by: Nicholas Bellinger

target: Follow up core updates from AGrover and HCH (round 4)

2011-07-22T09:37:48+00:00

This patch contains the squashed version of forth round series cleanups
from Andy and Christoph following the post heavy lifting in the preceeding:
'Eliminate usage of struct se_mem' and 'Make all control CDBs scatter-gather'
changes.  This also includes a conversion of target core and the v3.0
mainline fabric modules (loopback and tcm_fc) to use pr_debug and the
CONFIG_DYNAMIC_DEBUG infrastructure!

These have been squashed into this third and final round for v3.1.

target: Remove ifdeffed code in t_g_process_write
target: Remove direct ramdisk code
target: Rename task_sg_num to task_sg_nents
target: Remove custom debug macros for pr_debug. Use pr_err().
target: Remove custom debug macros in mainline fabrics
target: Set WSNZ=1 in block limits VPD. Abort if WRITE_SAME sectors = 0
target: Remove transport do_se_mem_map callback
target: Further simplify transport_free_pages
target: Redo task allocation return value handling
target: Remove extra parentheses
target: change alloc_task call to take *cdb, not *cmd

(nab: Fix bogus struct file assignments in fd_do_readv and fd_do_writev)

Signed-off-by: Andy Grover 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger

target: Make all control CDBs scatter-gather

2011-07-22T09:37:48+00:00

Previously, some control CDBs did not allocate memory in pages for their
data buffer, but just did a kmalloc. This patch makes all cdbs allocate
pages.

This has the benefit of streamlining some paths that had to behave
differently when we used two allocation methods. The downside is that
all accesses to the data buffer need to kmap it before use, and need to
handle data in page-sized chunks if more than a page is needed for a given
command's data buffer.

Finally, note that cdbs with no data buffers are handled a little
differently. Before, SCSI_NON_DATA_CDBs would not call get_mem at all
(they'd be in the final else in transport_allocate_resources) but now
these will make it into generic_get_mem, but just not allocate any
buffers.

Signed-off-by: Andy Grover 
Signed-off-by: Nicholas Bellinger

target: Implement Block Device Characteristics VPD page

2011-07-22T09:37:47+00:00

Implement page B1h, Block Device Characteristics, so that we can report
a medium rotation rate of 1 (non-rotating / solid state) if the
is_nonrot device attribute is set; we update the iblock backend to set
this attribute if the underlying Linux block device has its nonrot
flag set.

Signed-off-by: Roland Dreier 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger

target: Make se_tmr_lock IRQ-safe

2011-07-22T09:37:45+00:00

transport_lookup_tmr_lun() can be called from interrupt context and
therefore needs to use IRQ-safe spinlock functions.  Fix this up, and
to make the locking work, convert the other uses of se_tmr_lock to be
IRQ-disabling.

Signed-off-by: Roland Dreier 
Signed-off-by: Nicholas Bellinger

target: Make se_dev_check_online() locking IRQ-safe

2011-07-22T09:37:45+00:00

se_dev_check_online() is called from transport_lookup_cmd_lun(), which
as discussed before may be called from interrupt context.  So it needs
to use spin_lock_irqsave() instead of spin_lock_irq() to avoid
enabling interrupts at the wrong time.

Signed-off-by: Roland Dreier 
Signed-off-by: Nicholas Bellinger

target: Make transport_lookup_cmd_lun() locking IRQ-safe

2011-07-22T09:37:45+00:00

transport_lookup_cmd_lun() may be called from interrupt context (eg
tcm_loop_allocate_core_cmd() calls it, and it has a comment that says,
"Can be called from interrupt context"), so it needs to use
spin_lock_irqsave() instead of spin_lock_irq() to avoid enabling
interrupts at the wrong time.

(And indeed the last set of lock operations, on lun_cmd_lock, were
already using spin_lock_irqsave(), so we just need to fix the other
two locks we take)

Signed-off-by: Roland Dreier 
Signed-off-by: Nicholas Bellinger