SCSI sg table allocation has a maximum size (of SCSI_MAX_SG_SEGMENTS,
currently 128) and this will cause a BUG_ON() in SCSI if something
tries an allocation over it. This patch adds a size limit to the
chaining allocator to allow the specification of the maximum
allocation size for chaining, so we always chain in units of the
maximum SCSI allocation size.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch converts scsi mid-layer to use blk_end_request interfaces.
Related 'uptodate' arguments are converted to 'error'.
As a result, the interface of internal function, scsi_end_request(),
is changed.
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Also change scsi_alloc_sgtable() to just return 0/failure, since it
maps to the command passed in. ->request_buffer is now no longer needed,
once drivers are adapted to use scsi_sglist() it can be killed.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This replaces sizeof sense_buffer with SCSI_SENSE_BUFFERSIZE in
several LLDs. It's a preparation for the future changes to remove
sense_buffer array in scsi_cmnd structure.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch relaxes the default SCSI DMA alignment from 512 bytes to 4
bytes. I remember from previous discussions that usb and firewire have
sector size alignment requirements, so I upped their alignments in the
respective slave allocs.
The reason for doing this is so that we don't get such a huge amount of
copy overhead in bio_copy_user() for udev. (basically all inquiries it
issues can now be directly mapped).
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The current scsi_test_unit_ready() is updated to return sense code
information (in struct scsi_sense_hdr). The sd and sr drivers are
changed to interpret the sense code return asc 0x3a as no media and
adjust the device status accordingly.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
If blk_rq_map_sg wrote more than was allocated in the scatterlist,
BUG_ON() is probably the right thing to do.
[jejb: rejections fixed up]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Some SCSI tape medium changers that need the BLIST_SINGLELUN flag have
the medium changer at one LUN and the tape drive at a different LUN.
The inquiry string of the tape drive may be different from that of the
medium changer. In order for single_lun to be effective, every
scsi_device under a given scsi_target must have it set. This means that
there needs to be a blacklist entry for BOTH the medium changer AND the
tape drive, which is impractical because some medium changers may be
paired with a variety of different tape drive models. It makes more
sense to put the single_lun flag in scsi_target instead of scsi_device,
which causes every device at a given target ID to inherit the single_lun
flag from one LUN. This makes it possible to blacklist just the medium
changer and not the tape drive.
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add Documentation/DocBook/scsi_midlayer.tmpl, add to Makefile, and update
lots of kerneldoc comments in drivers/scsi/*.
Updated with comments from Stefan Richter, Stephen M. Cameron,
James Bottomley and Randy Dunlap.
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This reverts commit ac40532ef0, which gets
us back the original cleanup of 6f5391c283.
It turns out that the bug that was triggered by that commit was
apparently not actually triggered by that commit at all, and just the
testing conditions had changed enough to make it appear to be due to it.
The real problem seems to have been found by Peter Osterlund:
"pktcdvd sets it [block device size] when opening the /dev/pktcdvd
device, but when the drive is later opened as /dev/scd0, there is
nothing that sets it back. (Btw, 40944 is possible if the disk is a
CDRW that was formatted with "cdrwtool -m 10236".)
The problem is that pktcdvd opens the cd device in non-blocking mode
when pktsetup is run, and doesn't close it again until pktsetup -d is
run. The effect is that if you meanwhile open the cd device,
blkdev.c:do_open() doesn't call bd_set_size() because
bdev->bd_openers is non-zero."
In particular, to repeat the bug (regardless of whether commit
6f5391c283 is applied or not):
" 1. Start with an empty drive.
2. pktsetup 0 /dev/scd0
3. Insert a CD containing an isofs filesystem.
4. mount /dev/pktcdvd/0 /mnt/tmp
5. umount /mnt/tmp
6. Press the eject button.
7. Insert a DVD containing a non-writable filesystem.
8. mount /dev/scd0 /mnt/tmp
9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null
10. If the DVD contains data beyond the physical size of a CD, you
get I/O errors in the terminal, and dmesg reports lots of
"attempt to access beyond end of device" errors."
which in turn is because the nested open after the media change won't
cause the size to be set properly (because the original open still holds
the block device, and we only do the bd_set_size() when we don't have
other people holding the device open).
The proper fix for that is probably to just do something like
bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9;
in fs/block_dev.c:do_open() even for the cases where we're not the
original opener (but *not* call bd_set_size(), since that will also
change the block size of the device).
Cc: Peter Osterlund <petero2@telia.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 6f5391c283 ("[SCSI]
Get rid of scsi_cmnd->done") that was supposed to be a cleanup commit,
but apparently it causes regressions:
Bug 9370 - v2.6.24-rc2-409-g9418d5d: attempt to access beyond end of device
http://bugzilla.kernel.org/show_bug.cgi?id=9370
this patch should be reintroduced in a more split-up form to make
testing of it easier.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A recent bug report:
http://bugzilla.kernel.org/show_bug.cgi?id=9674
Was caused because the ULDs now set their own prep functions, but
don't necessarily reset the prep function back to the SCSI default
when they are removed. This leads to panics if commands are sent to
the device after the module is removed because the prep_fn is still
pointing to the old module code. The fix for this is to implement a
bus remove method that resets the prep_fn pointer correctly before
calling the ULD specific driver remove method.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
sg_mark_end() overwrites the page_link information, but all users want
__sg_mark_end() behaviour where we just set the end bit. That is the most
natural way to use the sg list, since you'll fill it in and then mark the
end point.
So change sg_mark_end() to only set the termination bit. Add a sg_magic
debug check as well, and clear a chain pointer if it is set.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
A bit too eager - we definitely need to clear the sg table
initially, so that we don't accidentally have ->page & 0x01
true and think that is a chain pointer.
This reverts commit f5c0dde4c6.
This reverts sg segment size ifdefs that the current code has in order
to provide a way to reduce sgpool memory consumption.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This option is true if a low-level driver can support sg
chaining. This will be removed eventually when all the drivers are
converted to support sg chaining. q->max_phys_segments is set to
SCSI_MAX_SG_SEGMENTS if false.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is what enables large commands. If we need to allocate an
sgtable that doesn't fit in a single page, allocate several
SCSI_MAX_SG_SEGMENTS sized tables and chain them together.
SCSI defaults to large chained sg tables, if the arch supports it.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Just pass in the command, no point in passing in the scatterlist
and scatterlist pool index seperately.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This converts the SCSI mid layer to using the sg helpers for looking up
sg elements, instead of doing it manually.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The ULD ->done callback moves into the scsi_driver. By moving the call
to scsi_io_completion() from scsi_blk_pc_done() to scsi_finish_command(),
we can eliminate the latter entirely. By returning 'good_bytes' from
the ->done callback (rather than invoking scsi_io_completion()), we can
stop exporting scsi_io_completion().
Also move the prototypes from sd.h to sd.c as they're all internal anyway.
Rename sd_rw_intr to sd_done and rw_intr to sr_done.
Inspired-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Because scsi_print_sense_hdr prefixes with KERN_INFO, the output from
scsi_io_completion looks like:
sd 0:0:0:0: [sdb] Device not ready: <6>: Sense Key : 0x2 [current]
: ASC=0x4 ASCQ=0x3
By using scsi_show_sense_hdr, we can get the much more appealing output:
sd 0:0:0:0: [sdb] Device not ready: Sense Key : 0x2 [current]
sd 0:0:0:0: [sdb] Device not ready: ASC=0x4 ASCQ=0x3
Acked-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
One of the intents of the block prep function was to allow ULDs to use
it for preprocessing. The original SCSI model was to have a single prep
function and add a pointer indirect filter to build the necessary
commands. This patch reverses that, does away with the init_command
field of the scsi_driver structure and makes ULDs attach directly to the
prep function instead. The value is really that it allows us to begin
to separate the ULDs from the SCSI mid layer (as long as they don't use
any core functions---which is hard at the moment---a ULD doesn't even
need SCSI to bind).
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
A BUSY status returned on a write request results in a stale residual
being returned when the write ultimately successfully completes.
This can be reproduced as follows:
1) issue immediate mode rewind to scsi tape drive
2) issue write request
The tape drive returns busy. The low level driver detects underrun and
sets the residual into the scsi command. The low level driver responds
with (DID_OK << 16) | scsi_status. scsi_status is 8, hence
status_byte(result) == 4, i.e., BUSY.
scsi_softirq_done() calls scsi_decide_disposition() which returns
ADD_TO_MLQUEUE. scsi_softirq_done() then calls scsi_queue_insert()
which, on the way to resubmitting the request to the driver, calls
scsi_init_cmd_errh().
The attached patch modifies scsi_init_cmd_errh() to clear the resid
field. This prevents a "stale" residual from being returned when the
scsi command finally completes without a BUSY status.
Signed-off-by: Michael Reed <mdr@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
sg's may have setup a the buffer with a different length than
the transfer length so we should be using the bufflen passed
in as the request's data len.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant. Remove it.
Now there is no need for bio_endio to subtract the size completed
from bi_size. So don't do that either.
While we are at it, change bi_end_io to return void.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
ll_back_merge_fn is currently exported to SCSI where is it used,
together with blk_rq_bio_prep, in exactly the same way these
functions are used in __blk_rq_map_user.
So move the common code into a new function (blk_rq_append_bio), and
don't export ll_back_merge_fn any longer.
Signed-off-by: Neil Brown <neilb@suse.de>
diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Our current implementation has a generic set of barrier functions that
go through the SCSI driver model. Realistically, this is unnecessary,
because the only device that can use barriers (sd) can set the flush
functions up at probe or revalidate time. This patch pulls the barrier
functions out of the mid layer and scsi driver model and relocates them
directly in sd.
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
With
dma-mapping-prevent-dma-dependent-code-from-linking-on.patch
scsi fails to build on !HAS_DMA architectures:
drivers/built-in.o(.text+0x20af6): In function `scsi_dma_map':
: undefined reference to `dma_map_sg'
drivers/built-in.o(.text+0x20b5c): In function `scsi_dma_unmap':
: undefined reference to `dma_unmap_sg'
I split those functions out into a new file. Builds on s390 and i386.
Move scsi_dma_{map,unmap} into scsi_lib_dma.c which is only build if
HAS_DMA is set.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This adds a set of accessors for the scsi data buffer. This is in
preparation for chaining sg lists and bidirectional requests (and
possibly, the mid-layer dma mapping).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Currently we scale the mempool sizes depending on memory installed
in the machine, except for the bio pool itself which sits at a fixed
256 entry pre-allocation.
There's really no point in "optimizing" this OOM path, we just need
enough preallocated to make progress. A single unit is enough, lets
scale it down to 2 just to be on the safe side.
This patch saves ~150kb of pinned kernel memory on a 32-bit box.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some targets can return both valid data and sense information.
Always update the request data_len from the SCSI command residual.
Callers should interpret sense data to determine what parts of the
data are valid in case of a CHECK CONDITION status.
Signed-off-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch enhances SCSI error printing by:
- Making use of scsi_print_result() in the completion functions.
- Having scmd_printk() output the disk name (when applicable).
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Joel Becker <Joel.Becker@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The KM_BIO_SRC_IRQ kmap slot must be taken with local irqs disabled. Add a
check into scsi for this.
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
scsi_retry_command only has a single caller, so there is no point
in having this function. Additionally the memset of the sense
buffer it does is entirely superflous as scsi_request_fn already
calls scsi_init_cmd_errh to perform this memset before the command
is reissued.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We have full flexibility of merging parameters now, so we can remove the
hooks that define back/front/request merge strategies. Nobody is using
them anymore.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's a file system thing, for block requests the only size used in the
io paths is ->data_len as it is in bytes, not sectors.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#
set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done
The script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the needed changes to the scsi-ml for the target
mode support.
Note, per the last review we moved almost all the fields we added
to the scsi_cmnd to our internal data structure which we are going
to try and kill off when we can replace it with support from other
parts of the kernel.
The one field we left on was the offset variable. This is needed to handle
the case where the target gets request that is so large that it cannot
execute it in one dma operation. So max_secotors or a segment limit may
limit the size of the transfer. In this case our tgt core code will
break up the command into managable transfers and send them to the
LLD one at a time. The offset is then used to tell the LLD where in
the command we are at. Is there another field on the scsi_cmd for
that?
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
ATAPI devices transfer fixed number of bytes for CDBs (12 or 16). Some
ATAPI devices choke when shorter CDB is used and the left bytes contain
garbage. Block SG_IO cleared left bytes but SCSI SG_IO didn't. This patch
makes SCSI SG_IO clear it and simplify CDB clearing in block SG_IO.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Mathieu Fluhr <mfluhr@nero.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Douglas Gilbert <dougg@torque.net>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: <stable@kernel.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I wanted to add some BUG checks to scsi_prep_fn to make sure no one
sends us a non-sg command, but this function is a horrible mess.
So I decided to detangle the function and document what the valid
cases are. While doing that I found that REQ_TYPE_SPECIAL commands
aren't used by the SCSI layer anymore and we can get rid of the code
handling them.
The new structure of scsi_prep_fn is:
(1) check if we're allowed to send this command
(2) big switch on cmd_type. For the two valid types call into
a function to set the command up, else error
(3) code to handle error cases
Because FS and BLOCK_PC commands are handled entirely separate after
the patch this introduces a tiny amount of code duplication. This
improves readabiulity though and will help to avoid the bidi command
overhead for FS commands so it's a good thing.
I've tested this on both sata and mptsas.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
In scsi_execute_async()'s error path, a struct scsi_io_context
allocated with kmem_cache_alloc() is kfree()'d. Obviously
kmem_cache_free() should be used instead.
Signed-off-by: Arne Redlich <arne.redlich@xiranet.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
James Bottomley