Commit graph

4,663 commits

Author SHA1 Message Date
Philipp Reisner
2d56a974f3 drbd: reset ap_in_flight counter for new connections
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-28 10:10:24 -06:00
Wei Yongjun
c613c5f686 mg_disk: fix error return code in mg_probe()
Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-28 09:43:43 -06:00
Vishal Verma
f8ebf8409a NVMe: Add definitions for format command
The SCSI emulation has the ability to send format commands, so we need
to add the definition of the command.  Also add a missing error code.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2013-03-27 07:17:49 -04:00
Vishal Verma
13c3b0fcc8 NVMe: Move structures & definitions to header file
nvme-scsi.c uses several data structures and definitions that were
previously private to nvme-core.c.  Move the definitions to nvme.h,
protected by __KERNEL__.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2013-03-27 07:05:42 -04:00
Philip J Kelleher
80b00df291 rsxx: remove unused variable
Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-26 14:48:12 -06:00
Philip J Kelleher
4dcaf47258 rsxx: enable error return of rsxx_eeh_save_issued_dmas()
Commit d8d595df introduced a bug where we did not check for a NULL
return from kmalloc(). Make rsxx_eeh_save_issued_dmas() return an
error for that case, and make the callers handle that.

Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-26 14:48:11 -06:00
Vishal Verma
729dd1bd80 NVMe: Rename nvme.c to nvme-core.c
In preparation for adding nvme-scsi.c
It is preferable to retain the module name 'nvme'

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2013-03-26 14:24:56 -04:00
Keith Busch
0e5e4f0e56 NVMe: Add discard support for capable devices
This adds discard support to block queues if the nvme device is capable of
deallocating blocks as indicated by the controller's optional command support.
A discard flagged bio request will submit an NVMe deallocate Data Set
Management command for the requested blocks.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2013-03-26 14:18:58 -04:00
Philip J Kelleher
d8d595dfce block: removes dynamic allocation on stack
This patch removes dynamic allocation on the stack error.

Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 19:22:31 -06:00
Jens Axboe
2124469efa aoe: get rid of cached bv variable in bufinit()
Less error prone if we just kill it, it's only used once
anyway.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 15:27:26 -06:00
Kent Overstreet
f1fb3449ef aoe: Fix unitialized var usage
Commit 4f2ac93c17 (block: Remove bi_idx
references) accidently removed the bit that set bv - readd that.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: fengguang.wu@intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 13:46:14 -06:00
Kent Overstreet
d74c6d514f block: Add bio_for_each_segment_all()
__bio_for_each_segment() iterates bvecs from the specified index
instead of bio->bv_idx.  Currently, the only usage is to walk all the
bvecs after the bio has been advanced by specifying 0 index.

For immutable bvecs, we need to split these apart;
bio_for_each_segment() is going to have a different implementation.
This will also help document the intent of code that's using it -
bio_for_each_segment_all() is only legal to use for code that owns the
bio.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Neil Brown <neilb@suse.de>
CC: Boaz Harrosh <bharrosh@panasas.com>
2013-03-23 14:26:28 -07:00
Kent Overstreet
ff8e0070d1 pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage
In the short term this'll help with code auditing, and if this code ever
gets used now it's converted :)

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jiri Kosina <jkosina@suse.cz>
2013-03-23 14:15:37 -07:00
Kent Overstreet
ffb25dc60f pktcdvd: use bio_copy_data()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Jiri Kosina <jkosina@suse.cz>
2013-03-23 14:15:37 -07:00
Kent Overstreet
4f2ac93c17 block: Remove bi_idx references
For immutable bvecs, all bi_idx usage needs to be audited - so here
we're removing all the unnecessary uses.

Most of these are places where it was being initialized on a bio that
was just allocated, a few others are conversions to standard macros.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
2013-03-23 14:15:31 -07:00
Kent Overstreet
aa8b57aa3d block: Use bio_sectors() more consistently
Bunch of places in the code weren't using it where they could be -
this'll reduce the size of the patch that puts bi_sector/bi_size/bi_idx
into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: "Ed L. Cashin" <ecashin@coraid.com>
CC: Nick Piggin <npiggin@kernel.dk>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Jim Paris <jim@jtan.com>
CC: Geoff Levand <geoff@infradead.org>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ed Cashin <ecashin@coraid.com>
2013-03-23 14:15:30 -07:00
Kent Overstreet
f73a1c7d11 block: Add bio_end_sector()
Just a little convenience macro - main reason to add it now is preparing
for immutable bio vecs, it'll reduce the size of the patch that puts
bi_sector/bi_size/bi_idx into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
CC: linux-s390@vger.kernel.org
CC: Chris Mason <chris.mason@fusionio.com>
CC: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
2013-03-23 14:15:29 -07:00
Lars Ellenberg
5bbcf5e6ab drbd: adjust upper limit for activity log extents
Now that the on-disk activity-log ring buffer size is adjustable,
the maximum active set can become larger, and is now limited by
the use of 16bit "labels".

This increases the maximum working set from 6433 to 65534 extents,
each of which covers an area of 4MiB.
Which means that if you use the maximum, you'd have to resync
more than 250 GiB after an unclean Primary shutdown.
With capable backend storage and replication links,
this is entirely feasible.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 22:18:09 -06:00
Lars Ellenberg
45ad07b3ac drbd: try hard to max out the updates per AL transaction
There may have been more incoming requests while we where preparing
the current transaction. Try to consolidate more updates into this
transaction until we make no more progres.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 22:18:09 -06:00
Lars Ellenberg
7e8c288f6c drbd: move start io accounting before activity log transaction
The IO accounting of the drbd "queue depth" was misleading.
We only started IO accounting once we already wrote the activity log.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 22:18:09 -06:00
Lars Ellenberg
08a1ddab6d drbd: consolidate as many updates as possible into one AL transaction
Depending on current IO depth, try to consolidate as many updates
as possible into one activity log transaction.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 22:18:09 -06:00
Lars Ellenberg
779b3fe4c0 drbd: queue writes on submitter thread, unless they pass the activity log fastpath
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:15:17 -06:00
Lars Ellenberg
6c3c4355d6 drbd: split out some helper functions to drbd_al_begin_io
To make the code easier to follow,
use an explicit find_active_resync_extent(),
and add a "nonblock" parameter to _al_get().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:15:17 -06:00
Lars Ellenberg
b5bc8e0864 drbd: split drbd_al_begin_io into fastpath, prepare, and commit
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:15:17 -06:00
Lars Ellenberg
113fef9e20 drbd: prepare to queue write requests on a submit worker
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:14:40 -06:00
Lars Ellenberg
6d9febe237 drbd: split __drbd_make_request in before and after drbd_al_begin_io
This is in preparation to be able to defer requests that need to wait
for an activity log transaction to a submitter workqueue.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:14:00 -06:00
Lars Ellenberg
ebfd5d8f71 drbd: drbd_al_being_io: short circuit to reduce latency
A request hitting an already "hot" extent should proceed right away,
even if some other requests need to wait for pending transactions.

Without that short-circuit, several simultaneous make_request contexts
race for committing the transaction, possibly penalizing the innocent.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:14:00 -06:00
Lars Ellenberg
56392d2f40 drbd: Clarify when activity log I/O is delegated to the worker thread
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:14:00 -06:00
Lars Ellenberg
c04ccaa669 drbd: read meta data early, base on-disk offsets on super block
We used to calculate all on-disk meta data offsets, and then compare
the stored offsets, basically treating them as magic numbers.

Now with the activity log striping, the activity log size is no longer
fixed.  We need to first read the super block, then base the activity
log and bitmap offsets on the stored offsets/al stripe settings.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:13:59 -06:00
Lars Ellenberg
cccac9857d drbd: mechanically rename la_size to la_size_sect
Make it obvious that this value is in units of 512 Byte sectors.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:13:59 -06:00
Lars Ellenberg
68e41a43f1 drbd: use the cached meta_dev_idx
Now we have the cached meta_dev_idx member,
we can get rid of a few rcu_read_lock() sections and rcu_dereference().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:13:59 -06:00
Lars Ellenberg
3a4d4eb3cb drbd: prepare for new striped layout of activity log
Introduce two new on-disk meta data fields: al_stripes and al_stripe_size_4k
The intended use case is activity log on RAID 0 or similar.
Logically consecutive transactions will advance their on-disk position
by al_stripe_size_4k 4kB (transaction sized) blocks.

Right now, these are still asserted to be the backward compatible
values al_stripes = 1, al_stripe_size_4k = 8 (which amounts to 32kB).

Also introduce a caching member for meta_dev_idx in the in-core
structure: even though it is initially passed in in the rcu-protected
disk_conf structure, it cannot change without a detach/attach cycle.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:13:59 -06:00
Lars Ellenberg
ae8bf312e9 drbd: cleanup ondisk meta data layout calculations and defines
Add a comment about our meta data layout variants,
and rename a few defines (e.g. MD_RESERVED_SECT -> MD_128MB_SECT)
to make it clear that they are short hand for fixed constants,
and not arbitrarily to be redefined as one may see fit.

Properly pad struct meta_data_on_disk to 4kB,
and initialize to zero not only the first 512 Byte,
but all of it in drbd_md_sync().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:13:59 -06:00
Lars Ellenberg
9114d79569 drbd: cleanup bogus assert message
This fixes ASSERT( mdev->state.disk == D_FAILED ) in drivers/block/drbd/drbd_main.c

When we detach from local disk, we let the local refcount hit zero twice.

First, we transition to D_FAILED, so we won't give out new references
to incoming requests; we still may give out *internal* references, though.
Once the refcount hits zero [1] while in D_FAILED, we queue a transition
to D_DISKLESS to our worker.  We need to queue it, because we may be in
atomic context when putting the reference.
Once the transition to D_DISKLESS actually happened [2] from worker context,
we don't give out new internal references either.

Between hitting zero the first time [1] and actually transition to
D_DISKLESS [2], there may be a few very short lived internal get/put,
so we may hit zero more than once while being in D_FAILED, or even see a
race where a an internal get_ldev() happened while D_FAILED, but the
corresponding put_ldev() happens just after the transition to D_DISKLESS.

That's why we have the additional test_and_set_bit(GO_DISKLESS,);
and that's why the assert was placed wrong.
Since there was exactly one code path left to drbd_go_diskless(),
and that checks already for D_FAILED, drop that assert,
and fold in the drbd_queue_work().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 18:13:59 -06:00
Linus Torvalds
5da273fe3f Merge git://git.infradead.org/users/willy/linux-nvme
Pull NVMe driver update from Matthew Wilcox:
 "These patches have mostly been baking for a few months; sorry I didn't
  get them in during the merge window.  They're all bug fixes, except
  for the addition of the SMART log and the addition to MAINTAINERS."

* git://git.infradead.org/users/willy/linux-nvme:
  NVMe: Add namespaces with no LBA range feature
  MAINTAINERS: Add entry for the NVMe driver
  NVMe: Initialize iod nents to 0
  NVMe: Define SMART log
  NVMe: Add result to nvme_get_features
  NVMe: Set result from user admin command
  NVMe: End queued bio requests when freeing queue
  NVMe: Free cmdid on nvme_submit_bio error
2013-03-22 16:43:53 -07:00
Keith Busch
122090366d NVMe: Add namespaces with no LBA range feature
The LBA Range Type feature is optional in the NVMe specification,
so we should continue with adding namespaces for controllers that do
not implement this feature.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2013-03-22 14:50:23 -04:00
Wei Yongjun
d2b805d895 cciss: fix invalid use of sizeof in cciss_find_cfgtables()
sizeof() when applied to a pointer typed expression gives the
size of the pointer, not that of the pointed data.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: scameron@beardog.cce.hp.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 12:22:49 -06:00
Phillip Susi
8761a3dc1f loop: cleanup partitions when detaching loop device
Any partitions added by user space to the loop device were being
left in place after detaching the loop device.  This was because
the detach path issued a BLKRRPART to clean up partitions if
LO_FLAGS_PARTSCAN was set, meaning that the partitions were auto
scanned on attach.  Replace this BLKRRPART with code that
unconditionally cleans up partitions on detach instead.

Signed-off-by: Phillip Susi <psusi@ubuntu.com>

Modified by Jens to export delete_partition().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 12:21:53 -06:00
Wei Yongjun
183cfb5720 loop: fix error return code in loop_add()
Fix to return a negative error code from the error handling
case, as returned elsewhere in this function.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 08:59:19 -06:00
Wei Yongjun
d137c8306c mtip32xx: fix error return code in mtip_pci_probe()
Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22 08:58:23 -06:00
Jens Axboe
7fbaee72ff Merge branch 'stable/for-jens-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus
Konrad writes:

[the branch] has a bunch of fixes. They vary from being able to deal
with unknown requests, overflow in statistics, compile warnings, bug in
the error path, removal of unnecessary logic. There is also one
performance fix - which is to allocate pages for requests when the
driver loads - instead of doing it per request
2013-03-22 08:56:32 -06:00
Rusty Russell
0a11cc36f7 virtio_blk: remove nents member.
It's simply a flag as to whether we have data now, so make it an
explicit function parameter rather than a member of struct
virtblk_req.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
2013-03-20 15:44:58 +10:30
Paolo Bonzini
20af3cfd20 virtio-blk: use virtqueue_add_sgs on req path
(This is a respin of Paolo Bonzini's patch, but it calls
virtqueue_add_sgs() instead of his multi-part API).

This is similar to the previous patch, but a bit more radical
because the bio and req paths now share the buffer construction
code.  Because the req path doesn't use vbr->sg, however, we
need to add a couple of arguments to __virtblk_add_req.

We also need to teach __virtblk_add_req how to build SCSI command
requests.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
2013-03-20 15:44:55 +10:30
Paolo Bonzini
8f39db9d37 virtio-blk: use virtqueue_add_sgs on bio path
(This is a respin of Paolo Bonzini's patch, but it calls
virtqueue_add_sgs() instead of his multi-part API).

Move the creation of the request header and response footer to
__virtblk_add_req.  vbr->sg only contains the data scatterlist,
the header/footer are added separately using virtqueue_add_sgs().

With this change, virtio-blk (with use_bio) is not relying anymore on
the virtio functions ignoring the end markers in a scatterlist.
The next patch will do the same for the other path.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
2013-03-20 15:44:54 +10:30
Paolo Bonzini
5ee21a52c0 virtio-blk: reorganize virtblk_add_req
Right now, both virtblk_add_req and virtblk_add_req_wait call
virtqueue_add_buf.  To prepare for the next patches, abstract the call
to virtqueue_add_buf into a new function __virtblk_add_req, and include
the waiting logic directly in virtblk_add_req.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-03-20 15:44:54 +10:30
Roger Pau Monne
b1173e316b xen-blkfront: remove frame list from blk_shadow
We already have the frame (pfn of the grant page) stored inside struct
grant, so there's no need to keep an aditional list of mapped frames
for a specific request. This reduces memory usage in blkfront.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-03-19 12:50:07 -04:00
Roger Pau Monne
9c1e050cae xen-blkfront: pre-allocate pages for requests
This prevents us from having to call alloc_page while we are preparing
the request. Since blkfront was calling alloc_page with a spinlock
held we used GFP_ATOMIC, which can fail if we are requesting a lot of
pages since it is using the emergency memory pools.

Allocating all the pages at init prevents us from having to call
alloc_page, thus preventing possible failures.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-03-19 12:50:06 -04:00
Roger Pau Monne
ffb1dabd1e xen-blkback: don't store dev_bus_addr
dev_bus_addr returned in the grant ref map operation is the mfn of the
passed page, there's no need to store it in the persistent grant
entry, since we can always get it provided that we have the page.

This reduces the memory overhead of persistent grants in blkback.

While at it, rename the 'seg[i].buf' to be 'seg[i].offset' as
it makes much more sense - as we use that value in bio_add_page
which as the fourth argument expects the offset.

We hadn't used the physical address as part of this at all.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
[v1: s/buf/offset/]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-03-19 12:50:00 -04:00
Roger Pau Monne
155b7edb51 xen-blkfront: switch from llist to list
The git commit f84adf4921
(xen-blkfront: drop the use of llist_for_each_entry_safe)

was a stop-gate to fix a GCC4.1 bug. The appropiate way
is to actually use an list instead of using an llist.

As such this patch replaces the usage of llist with an
list.

Since we always manipulate the list while holding the io_lock, there's
no need for additional locking (llist used previously is safe to use
concurrently without additional locking).

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
CC: stable@vger.kernel.org
[v1: Redid the git commit description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-03-19 10:27:56 -04:00
Roger Pau Monne
217fd5e709 xen-blkback: fix foreach_grant_safe to handle empty lists
We may use foreach_grant_safe in the future with empty lists, so make
sure we can handle them.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-03-19 08:53:15 -04:00