This patch adds support for emulation of WRITE_SAME w/ UNMAP=1 within
fd_execute_write_same_unmap() backend code.

If the FILEIO backend is normal file, the emulation uses fallocate to
punch hole to reclaim the free space used by the file. If the FILEIO
backend is block device, the emulation uses blkdev_issue_discard().

Tested with 512, 1k, 2k, and 4k block_sizes.

Changes in v2:
- Set the various dev->dev_attrib.*unmap* values (nab)

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NAsias He <asias@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Inclues sbp_exit, fileio_module_exit, iblock_module_exit and
pscsi_module_exit.

Note: rd_module_exit() can not be annotated by __exit, becasue it is
called by target_core_init_configfs() which is annotated by __init.
Signed-off-by: NAsias He <asias@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Trivial, but WRITE SAME is an SBC command so it seems strange for a
related function (defined in target_core_sbc.c) to be in the spc_
namespace.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch adds support for emulation of WRITE_SAME w/ UNMAP=0 within
fd_execute_write_same() backend code.

The emulation uses vfs_writev() to submit a locally populated buffer
from the received WRITE_SAME scatterlist block for duplication, and by
default enforces a limit of max_write_same_len=0x1000 (8192) sectors up
to the limit of 1024 iovec entries for the single call to vfs_writev().

It also sets max_write_same_len to the operational default at setup ->
fd_configure_device() time.

Tested with 512, 1k, 2k, and 4k block_sizes.

(asias: convert to vzalloc)

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Asias He <asias@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Those two functions are almost identical so merge them. Noticed this
while fixing the highmem in both cases.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch changes vectored file I/O to use kmap + kunmap when mapping
incoming SGL memory -> struct iovec in order to properly support 32-bit
highmem configurations.  This is because an extra bounce buffer may be
required when processing scatterlist pages allocated with GFP_KERNEL.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

v2: Use correct target_core_stat.c 2006 copyright year
v3: Drop extra unnessary legal verbage from header (hch)

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values.  This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.

(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
      sense_reason_t with Roland's MODE SELECT changes)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that the reservations and ALUA code have been cleaned up there is no need
for the get_device_rev method, as we only need the standards revision in the
inquiry data, where we can hardcode it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

These really are sbc_ops, so name them correctly.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Simplify the code a lot by killing the superflous struct se_subsystem_dev.
Instead se_device is allocated early on by the backend driver, which allocates
it as part of its own per-device structure, borrowing the scheme that is for
example used for inode allocation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch re-adds the ability to optionally run in buffered FILEIO mode
(eg: w/o O_DSYNC) for device backends in order to once again use the
Linux buffered cache as a write-back storage mechanism.

This logic was originally dropped with mainline v3.5-rc commit:

commit a4dff304
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date:   Wed May 30 16:25:41 2012 -0700

    target/file: Use O_DSYNC by default for FILEIO backends

This difference with this patch is that fd_create_virtdevice() now
forces the explicit setting of emulate_write_cache=1 when buffered FILEIO
operation has been enabled.

(v2: Switch to FDBD_HAS_BUFFERED_IO_WCE + add more detailed
     comment as requested by hch)
Reported-by: NFerry <iscsitmp@bananateam.nl>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch drops se_subsystem_api->[write_cache,fua_write]_emulated flags
set by viritual FILEIO/IBLOCK/RD_MCP backend drivers in favor of explict
TRANSPORT_PLUGIN_PHBA_PDEV checks to know when to fail if userspace is
attempting to set virtual emulation bits for an pSCSI (passthrough)
backend device.
Reported-by: NChristoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

* set_fs(KERNEL_DS) + getname() is probably the weirdest implementation
of strdup() I've seen.  Especially since they don't to copy it at all...
* filp_open() never returns NULL; it's ERR_PTR(-E...) on failure.
* file->f_dentry is never going to be NULL, TYVM.
* match_strdup() + snprintf() + kfree() is a bloody weird way to spell
match_strlcpy().

Pox on cargo-cult programmers...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add spc_ops->execute_sync_cache() caller for ->execute_cmd() setup,
and update IBLOCK + FILEIO backends to use it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Remove the execute_cmd method in struct se_subsystem_api, and always use the
one directly in struct se_cmd.  To make life simpler for SBC virtual backends
a struct spc_ops that is passed to sbc_parse_cmd is added.  For now it
only contains an execute_rw member, but more will follow with the subsequent
commits.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Instead of trying to handle all SCSI command sets in one function
(transport_generic_cmd_sequencer) call out to the backend driver to perform
this functionality.  For pSCSI a copy of the existing code is used, but for
all virtual backends we can use a new parse_sbc_cdb helper is used to
provide a simple SBC emulation.

For now this setups means a fair amount of duplication between pSCSI and the
SBC library, but patches later in this series will sort out that problem.

(nab: Fix up build failure in target_core_pscsi.c)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Convert to use O_DSYNC for all cases at FILEIO backend creation time to
avoid the extra syncing of pure timestamp updates with legacy O_SYNC during
default operation as recommended by hch.  Continue to do this independently of
Write Cache Enable (WCE) bit, as WCE=0 is currently the default for all backend
devices and enabled by user on per device basis via attrib/emulate_write_cache.

This patch drops the now unnecessary fd_buffered_io= token usage that was
originally signalling when to explictly disable O_SYNC at backend creation
time for buffered I/O operation.  This can end up being dangerous for a number
of reasons during physical node failure, so go ahead and drop this option
for now when O_DSYNC is used as the default.

Also allow explict FUA WRITEs -> vfs_fsync_range() call to function in
fd_execute_cmd() independently of WCE bit setting.
Reported-by: NChristoph Hellwig <hch@lst.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a bug in the handling of FILEIO w/ underlying block_device
resize operations where the original fd_dev->fd_dev_size was incorrectly being
used in fd_get_blocks() for READ_CAPACITY response payloads.

This patch avoids using fd_dev->fd_dev_size for FILEIO devices with
an underlying block_device, and instead changes fd_get_blocks() to
get the sector count directly from i_size_read() as recommended by hch.
Reported-by: NChristoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We can use struct se_cmd for everything it did.  Make sure to pass the S/G
list and data direction to the execution function to ease adding back BIDI
support later on.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Make CDB emulation work on commands instead of tasks again as a preparation
of removing tasks completely.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that we don't split commands the size field in the task is always
equivalent to the one in the CDB, even in cases where we have two tasks
due to a BIDI transfer.  Just refer the the size in the command instead
of duplicating it in the task.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that we don't split commands the lba field in the task is always
equivalent to the one in the CDB, even in cases where we have two tasks
due to a BIDI transfer.  Just refer the the lba in the command instead
of duplicating it in the task.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch includes the handful of squashed patches for target/iscsi from
Andy's original series into lio-core/master code:

*) Make iscsit_add_reject static
*) Remove unused data_offset_end from iscsi_datain_req
*) Remove "#if 0" stubs
*) Rename iscsi_datain_req to cmd_datain_node
*) Cleanups for built_r2ts_for_cmd()
*) Cleanups for Cleanup build_sendtargets_response()
Signed-off-by: NAndy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

A reader should spend an extra moment whenever noticing a cast,
because either something special is going on that deserves extra
attention or, as is all too often the case, the code is wrong.

These casts, afaics, have all been useless.  They cast a foo* to a
foo*, cast a void* to the assigned type, cast a foo* to void*, before
assigning it to a void* variable, etc.

In a few cases I also removed an additional &...[0], which is equally
useless.

Lastly I added three FIXMEs where, to the best of my judgement, the
code appears to have a bug.  It would be good if someone could check
these.
Signed-off-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The command
| echo rd_pages=32768 > ramdisk/control

Does not work because it writes "rd_pages=32768\n" and the parser which
matches for "rd_pages=%d" does not recognize it due to the \n. One way
of fixing this would be using "echo -n" instead.
This patch adds \n to the list of separators so we don't have to use the
-n argument which I find is more convinient.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This reorganized the headers under include/target into:

 - target_core_base.h stays as is with all target-wide data stuctures and defines
 - target_core_backend.h contains the whole interface to I/O backends
 - target_core_fabric.h contains the whole interface to fabric modules

Except for those only the various configfs macro headers stay around.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch changes fileio to use for_each_sg() when walking se_task->task_sg
memory passed into from loopback LLD struct scsi_cmnd scatterlist memory.

This addresses an issue where FILEIO backends with loopback where hitting the
following OOPs with mkfs.ext2:

|kernel BUG at include/linux/scatterlist.h:97!
|invalid opcode: 0000 [#1] PREEMPT SMP
|Modules linked in: sd_mod tcm_loop target_core_stgt scsi_tgt target_core_pscsi target_core_file target_core_iblock target_core_mod configfs scsi_mod
|
|Pid: 671, comm: LIO_fileio Not tainted 3.1.0-rc10+ #139 Bochs Bochs
|EIP: 0060:[<e0afd746>] EFLAGS: 00010202 CPU: 0
|EIP is at fd_do_task+0x396/0x420 [target_core_file]
| [<e0aa7884>] __transport_execute_tasks+0xd4/0x190 [target_core_mod]
| [<e0aa797c>] transport_execute_tasks+0x3c/0xf0 [target_core_mod]
|EIP: [<e0afd746>] fd_do_task+0x396/0x420 [target_core_file] SS:ESP 0068:dea47e90
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

And use a SCF_FUA flag instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch removes legacy usage of PYX_TRANSPORT_* return codes in a number
of locations and addresses cases where transport_generic_request_failure()
was returning the incorrect sense upon CHECK_CONDITION status after the
v3.1 converson to use errno return codes.

This includes the conversion of transport_generic_request_failure() to
process cmd->scsi_sense_reason and handle extra TCM_RESERVATION_CONFLICT
before calling transport_send_check_condition_and_sense() to queue up
response status.  It also drops PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES legacy
usgae, and returns TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE w/ a response
for these cases.

transport_generic_allocate_tasks(), transport_generic_new_cmd(), backend
SCF_SCSI_DATA_SG_IO_CDB ->do_task(), and emulated ->execute_task() have
all been updated to set se_cmd->scsi_sense_reason and return errno codes
universally upon failure.  This includes cmd->scsi_sense_reason assignment
in target_core_alua.c, target_core_pr.c and target_core_cdb.c emulation code.

Finally it updates fabric modules to remove the legacy usage, and for
TFO->new_cmd_map() callers forwards return values outside of fabric code.
iscsi-target has also been updated to remove a handful of special cases
related to the cleanup and signaling QUEUE_FULL handling w/ ft_write_pending()

(v2: Drop extra SCF_SCSI_CDB_EXCEPTION check during failure from
     transport_generic_new_cmd, and re-add missing task->task_error_status
     assignment in transport_complete_task)

Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Remove the dpo_emulated, fua_write_emulated, fua_read_emulated and
write_cache_emulated methods, and replace them with a simple bitfields in
se_subsystem_api in those cases where they ever returned one.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The most commonly used file, iblock and rd backends have no use for
a per-task CDB and thus don't need a method to copy it into their
otherwise unused CDB fields.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This is a squashed version of the following se_task cleanup patches:

    target: remove the unused task_state_flags field in se_task
    target: remove the unused se_obj_ptr field in se_task
    target: remove the se_dev field in se_task
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/target/.
This patch removes them.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/target/.
This patch removes them.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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: NAndy Grover <agrover@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch contains a squashed version of third round series cleanups,
improvements ,and simplfications from Andy and Christoph ahead of the
heavy lifting between round 3 -> 4 for the target core SGL conversion.

This include cleanups to the main target I/O path and other miscellaneous
updates.

target: Replace custom sg<->buf functions with lib funcs
target: Simplify sector limiting code
target: get_cdb should never return NULL
target: Simplify transport_memcpy_se_mem_read_contig
target: Use assignment rather than increment for t_task_cdbs
target: Don't pass dma_size to generic_get_mem
target: Pass sg with type scatterlist in transport_map_sg_to_mem
target: Move task_sg_num next to task_sg in struct se_task
target: inline struct se_transport_task into struct se_cmd
target: Change name & semantics of transport_get_sectors()
target: Remove unused members of se_cmd
target: Rename se_cmd.t_task_cdbs to t_task_list_num
target: Fix some spelling
target: Remove unused var from transport_generic_do_tmr
target: map_sg_to_mem: return sg_count in return value
target/pscsi: Use min_t for sector limits
target/pscsi: Unused param for pscsi_get_bio()
target: Rename get_cdb_count to allocate_tasks
target: Make transport_generic_new_cmd() available for iscsi-target
target: Remove fabric callback to allocate iovecs
target: Fix transport_generic_new_cmd WRITE comment

(hch: Use __GFP_ZERO usage for alloc_pages() usage)
Signed-off-by: NAndy Grover <agrover@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>