Commit Graph

185 Commits

Author SHA1 Message Date
Juergen Gross 6f2f39ad1a xen/blkback: remove unused pers_gnts_lock from struct xen_blkif_ring
pers_gnts_lock isn't being used anywhere. Remove it.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-08-27 12:12:04 -04:00
Juergen Gross d77ff24e7f xen/blkback: move persistent grants flags to bool
The struct persistent_gnt flags member is meant to be a bitfield of
different flags. There is only PERSISTENT_GNT_ACTIVE flag left, so
convert it to a bool named "active".

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-08-27 12:12:04 -04:00
Juergen Gross 973e5405f2 xen/blkback: don't keep persistent grants too long
Persistent grants are allocated until a threshold per ring is being
reached. Those grants won't be freed until the ring is being destroyed
meaning there will be resources kept busy which might no longer be
used.

Instead of freeing only persistent grants until the threshold is
reached add a timestamp and remove all persistent grants not having
been in use for a minute.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-08-27 12:12:03 -04:00
Kees Cook 6396bb2215 treewide: kzalloc() -> kcalloc()
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Joe Perches 5657a819a8 block drivers/block: Use octal not symbolic permissions
Convert the S_<FOO> symbolic permissions to their octal equivalents as
using octal and not symbolic permissions is preferred by many as more
readable.

see: https://lkml.org/lkml/2016/8/2/1945

Done with automated conversion via:
$ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...>

Miscellanea:

o Wrapped modified multi-line calls to a single line where appropriate
o Realign modified multi-line calls to open parenthesis

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-24 13:38:59 -06:00
Linus Torvalds a0725ab0c7 Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the first pull request for 4.14, containing most of the code
  changes. It's a quiet series this round, which I think we needed after
  the churn of the last few series. This contains:

   - Fix for a registration race in loop, from Anton Volkov.

   - Overflow complaint fix from Arnd for DAC960.

   - Series of drbd changes from the usual suspects.

   - Conversion of the stec/skd driver to blk-mq. From Bart.

   - A few BFQ improvements/fixes from Paolo.

   - CFQ improvement from Ritesh, allowing idling for group idle.

   - A few fixes found by Dan's smatch, courtesy of Dan.

   - A warning fixup for a race between changing the IO scheduler and
     device remova. From David Jeffery.

   - A few nbd fixes from Josef.

   - Support for cgroup info in blktrace, from Shaohua.

   - Also from Shaohua, new features in the null_blk driver to allow it
     to actually hold data, among other things.

   - Various corner cases and error handling fixes from Weiping Zhang.

   - Improvements to the IO stats tracking for blk-mq from me. Can
     drastically improve performance for fast devices and/or big
     machines.

   - Series from Christoph removing bi_bdev as being needed for IO
     submission, in preparation for nvme multipathing code.

   - Series from Bart, including various cleanups and fixes for switch
     fall through case complaints"

* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
  kernfs: checking for IS_ERR() instead of NULL
  drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
  drbd: Fix allyesconfig build, fix recent commit
  drbd: switch from kmalloc() to kmalloc_array()
  drbd: abort drbd_start_resync if there is no connection
  drbd: move global variables to drbd namespace and make some static
  drbd: rename "usermode_helper" to "drbd_usermode_helper"
  drbd: fix race between handshake and admin disconnect/down
  drbd: fix potential deadlock when trying to detach during handshake
  drbd: A single dot should be put into a sequence.
  drbd: fix rmmod cleanup, remove _all_ debugfs entries
  drbd: Use setup_timer() instead of init_timer() to simplify the code.
  drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
  drbd: new disk-option disable-write-same
  drbd: Fix resource role for newly created resources in events2
  drbd: mark symbols static where possible
  drbd: Send P_NEG_ACK upon write error in protocol != C
  drbd: add explicit plugging when submitting batches
  drbd: change list_for_each_safe to while(list_first_entry_or_null)
  drbd: introduce drbd_recv_header_maybe_unplug
  ...
2017-09-07 11:59:42 -07:00
Annie Li dc52d783d6 xen-blkback: stop blkback thread of every queue in xen_blkif_disconnect
In xen_blkif_disconnect, before checking inflight I/O, following code
stops the blkback thread,
if (ring->xenblkd) {
	kthread_stop(ring->xenblkd);
	wake_up(&ring->shutdown_wq);
}
If there is inflight I/O in any non-last queue, blkback returns -EBUSY
directly, and above code would not be called to stop thread of remaining
queue and processs them. When removing vbd device with lots of disk I/O
load, some queues with inflight I/O still have blkback thread running even
though the corresponding vbd device or guest is gone.
And this could cause some problems, for example, if the backend device type
is file, some loop devices and blkback thread always lingers there forever
after guest is destroyed, and this causes failure of umounting repositories
unless rebooting the dom0.
This patch allows thread of every queue has the chance to get stopped.
Otherwise, only thread of queue previous to(including) first busy one get
stopped, blkthread of remaining queue will still run.  So stop all threads
properly and return -EBUSY if any queue has inflight I/O.

Signed-off-by: Annie Li <annie.li@oracle.com>
Reviewed-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Reviewed-by: Bhavesh Davda <bhavesh.davda@oracle.com>
Reviewed-by: Adnan Misherfi <adnan.misherfi@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-08-25 15:59:34 -04:00
Christoph Hellwig 74d46992e0 block: replace bi_bdev with a gendisk pointer and partitions index
This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 12:49:55 -06:00
Bart Van Assche 3f2c9405fa xen-blkback: Avoid that gcc 7 warns about fall-through when building with W=1
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Roger Pau Monn303251 <roger.pau@citrix.com>
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18 08:36:58 -06:00
Bart Van Assche 306b82a806 xen-blkback: Fix indentation
Avoid that smatch reports the following warning when building with
C=2 CHECK="smatch -p=kernel":

drivers/block/xen-blkback/blkback.c:710 xen_blkbk_unmap_prepare() warn: inconsistent indenting

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Roger Pau Monn303251 <roger.pau@citrix.com>
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18 08:36:58 -06:00
Jens Axboe f95a0d6a95 Merge commit '8e8320c9315c' into for-4.13/block
Pull in the fix for shared tags, as it conflicts with the pending
changes in for-4.13/block. We already pulled in v4.12-rc5 to solve
other conflicts or get fixes that went into 4.12, so not a lot
of changes in this merge.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-22 21:55:24 -06:00
Jan Beulich 089bc0143f xen-blkback: don't leak stack data via response ring
Rather than constructing a local structure instance on the stack, fill
the fields directly on the shared ring, just like other backends do.
Build on the fact that all response structure flavors are actually
identical (the old code did make this assumption too).

This is XSA-216.

Cc: stable@vger.kernel.org

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13 16:28:32 -04:00
Juergen Gross a24fa22ce2 xen/blkback: don't use xen_blkif_get() in xen-blkback kthread
There is no need to use xen_blkif_get()/xen_blkif_put() in the kthread
of xen-blkback. Thread stopping is synchronous and using the blkif
reference counting in the kthread will avoid to ever let the reference
count drop to zero at the end of an I/O running concurrent to
disconnecting and multiple rings.

Setting ring->xenblkd to NULL after stopping the kthread isn't needed
as the kthread does this already.

Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Steven Haigh <netwiz@crc.id.au>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13 16:27:39 -04:00
Juergen Gross 71df1d7cca xen/blkback: don't free be structure too early
The be structure must not be freed when freeing the blkif structure
isn't done. Otherwise a use-after-free of be when unmapping the ring
used for communicating with the frontend will occur in case of a
late call of xenblk_disconnect() (e.g. due to an I/O still active
when trying to disconnect).

Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Steven Haigh <netwiz@crc.id.au>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13 16:09:41 -04:00
Juergen Gross 4646441130 xen/blkback: fix disconnect while I/Os in flight
Today disconnecting xen-blkback is broken in case there are still
I/Os in flight: xen_blkif_disconnect() will bail out early without
releasing all resources in the hope it will be called again when
the last request has terminated. This, however, won't happen as
xen_blkif_free() won't be called on termination of the last running
request: xen_blkif_put() won't decrement the blkif refcnt to 0 as
xen_blkif_disconnect() didn't finish before thus some xen_blkif_put()
calls in xen_blkif_disconnect() didn't happen.

To solve this deadlock xen_blkif_disconnect() and
xen_blkif_alloc_rings() shouldn't use xen_blkif_put() and
xen_blkif_get() but use some other way to do their accounting of
resources.

This at once fixes another error in xen_blkif_disconnect(): when it
returned early with -EBUSY for another ring than 0 it would call
xen_blkif_put() again for already handled rings on a subsequent call.
This will lead to inconsistencies in the refcnt handling.

Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Steven Haigh <netwiz@crc.id.au>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13 16:04:18 -04:00
Christoph Hellwig 4e4cbee93d block: switch bios to blk_status_t
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Gustavo A. R. Silva 2d4456c73a block: xen-blkback: add null check to avoid null pointer dereference
Add null check before calling xen_blkif_put() to avoid potential
null pointer dereference.

Addresses-Coverity-ID: 1350942
Cc: Juergen Gross <jgross@suse.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-05-15 17:14:28 -04:00
Juergen Gross 5584ea250a xen: modify xenstore watch event interface
Today a Xenstore watch event is delivered via a callback function
declared as:

void (*callback)(struct xenbus_watch *,
                 const char **vec, unsigned int len);

As all watch events only ever come with two parameters (path and token)
changing the prototype to:

void (*callback)(struct xenbus_watch *,
                 const char *path, const char *token);

is the natural thing to do.

Apply this change and adapt all users.

Cc: konrad.wilk@oracle.com
Cc: roger.pau@citrix.com
Cc: wei.liu2@citrix.com
Cc: paul.durrant@citrix.com
Cc: netdev@vger.kernel.org

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-02-09 11:26:49 -05:00
Linus Torvalds aa3ecf388a xen: features and fixes for 4.10 rc0
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQEcBAABAgAGBQJYT5HMAAoJELDendYovxMvhNQH/1g/3ahM4JKN8Z0SbjKBEdQm
 yj2xOj6cE3l6wMSUblKjZD2DLLhpmcHT/E97Xro/lZQEfQJoMXXWWDFowMU/P1LA
 mJxb7Fzq5Wr+6eGSAlIQB270MrpNi/luf+CWHMwVA3V7R3KRXwonOdGQSkISIzCd
 tgIydEA3a9r2+HgeIBpZFZ4GcSrJQU75krMyl2tjD1C+jeYVd+zdoj2OnDsZQDZQ
 hDWApMpNbpSBAn7JtSSdXWSTBsGH0lUECebeYPhPQ2sX2P6Y8+UCGwA7i6FFdbTa
 agXfVSdRz8dCe3k19VcKDAw6nK9BTTMnEeEHmkmygIh6wuHPP44CzigTXIbJoXI=
 =zjfm
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "Xen features and fixes for 4.10

  These are some fixes, a move of some arm related headers to share them
  between arm and arm64 and a series introducing a helper to make code
  more readable.

  The most notable change is David stepping down as maintainer of the
  Xen hypervisor interface. This results in me sending you the pull
  requests for Xen related code from now on"

* tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits)
  xen/balloon: Only mark a page as managed when it is released
  xenbus: fix deadlock on writes to /proc/xen/xenbus
  xen/scsifront: don't request a slot on the ring until request is ready
  xen/x86: Increase xen_e820_map to E820_X_MAX possible entries
  x86: Make E820_X_MAX unconditionally larger than E820MAX
  xen/pci: Bubble up error and fix description.
  xen: xenbus: set error code on failure
  xen: set error code on failures
  arm/xen: Use alloc_percpu rather than __alloc_percpu
  arm/arm64: xen: Move shared architecture headers to include/xen/arm
  xen/events: use xen_vcpu_id mapping for EVTCHNOP_status
  xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing
  xen-scsifront: Add a missing call to kfree
  MAINTAINERS: update XEN HYPERVISOR INTERFACE
  xenfs: Use proc_create_mount_point() to create /proc/xen
  xen-platform: use builtin_pci_driver
  xen-netback: fix error handling output
  xen: make use of xenbus_read_unsigned() in xenbus
  xen: make use of xenbus_read_unsigned() in xen-pciback
  xen: make use of xenbus_read_unsigned() in xen-fbfront
  ...
2016-12-13 16:07:55 -08:00
Juergen Gross 8235777b20 xen: make use of xenbus_read_unsigned() in xen-blkback
Use xenbus_read_unsigned() instead of xenbus_scanf() when possible.
This requires to change the type of one read from int to unsigned,
but this case has been wrong before: negative values are not allowed
for the modified case.

Cc: konrad.wilk@oracle.com
Cc: roger.pau@citrix.com

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
2016-11-07 13:55:07 +01:00
Christoph Hellwig 70fd76140a block,fs: use REQ_* flags directly
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly.  Where applicable this also drops usage of the
bio_set_op_attrs wrapper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01 09:43:26 -06:00
Linus Torvalds 08fd8c1768 xen: features and fixes for 4.8-rc0
- ACPI support for guests on ARM platforms.
 - Generic steal time support for arm and x86.
 - Support cases where kernel cpu is not Xen VCPU number (e.g., if
   in-guest kexec is used).
 - Use the system workqueue instead of a custom workqueue in various
   places.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJXmLlrAAoJEFxbo/MsZsTRvRQH/1wOMF8BmlbZfR7H3qwDfjst
 ApNifCiZE08xDtWBlwUaBFAQxyflQS9BBiNZDVK0sysIdXeOdpWV7V0ZjRoLL+xr
 czsaaGXDcmXxJxApoMDVuT7FeP6rEk6LVAYRoHpVjJjMZGW3BbX1vZaMW4DXl2WM
 9YNaF2Lj+rpc1f8iG31nUxwkpmcXFog6ct4tu7HiyCFT3hDkHt/a4ghuBdQItCkd
 vqBa1pTpcGtQBhSmWzlylN/PV2+NKcRd+kGiwd09/O/rNzogTMCTTWeHKAtMpPYb
 Cu6oSqJtlK5o0vtr0qyLSWEGIoyjE2gE92s0wN3iCzFY1PldqdsxUO622nIj+6o=
 =G6q3
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from David Vrabel:
 "Features and fixes for 4.8-rc0:

   - ACPI support for guests on ARM platforms.
   - Generic steal time support for arm and x86.
   - Support cases where kernel cpu is not Xen VCPU number (e.g., if
     in-guest kexec is used).
   - Use the system workqueue instead of a custom workqueue in various
     places"

* tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits)
  xen: add static initialization of steal_clock op to xen_time_ops
  xen/pvhvm: run xen_vcpu_setup() for the boot CPU
  xen/evtchn: use xen_vcpu_id mapping
  xen/events: fifo: use xen_vcpu_id mapping
  xen/events: use xen_vcpu_id mapping in events_base
  x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info
  x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op
  xen: introduce xen_vcpu_id mapping
  x86/acpi: store ACPI ids from MADT for future usage
  x86/xen: update cpuid.h from Xen-4.7
  xen/evtchn: add IOCTL_EVTCHN_RESTRICT
  xen-blkback: really don't leak mode property
  xen-blkback: constify instance of "struct attribute_group"
  xen-blkfront: prefer xenbus_scanf() over xenbus_gather()
  xen-blkback: prefer xenbus_scanf() over xenbus_gather()
  xen: support runqueue steal time on xen
  arm/xen: add support for vm_assist hypercall
  xen: update xen headers
  xen-pciback: drop superfluous variables
  xen-pciback: short-circuit read path used for merging write values
  ...
2016-07-27 11:35:37 -07:00
Jan Beulich aea305e11f xen-blkback: really don't leak mode property
Commit 9d092603cc ("xen-blkback: do not leak mode property") left one
path unfixed; correct this.

Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-07-22 08:24:43 -04:00
Jan Beulich 530439484d xen-blkback: constify instance of "struct attribute_group"
The functions these get passed to have been taking pointers to const
since at least 2.6.16.

Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-07-22 08:23:52 -04:00
Jan Beulich 6694389af9 xen-blkback: prefer xenbus_scanf() over xenbus_gather()
... for single items being collected: It is more typesafe (as the
compiler can check format string and to-be-written-to variable match)
and requires one less parameter to be passed.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
2016-07-22 08:23:38 -04:00
Christoph Hellwig 288dab8a35 block: add a separate operation type for secure erase
Instead of overloading the discard support with the REQ_SECURE flag.
Use the opportunity to rename the queue flag as well, and remove the
dead checks for this flag in the RAID 1 and RAID 10 drivers that don't
claim support for secure erase.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-09 09:52:25 -06:00
Mike Christie a022606e53 xen: use bio op accessors
Separate the op from the rq_flag_bits and have xen
set/get the bio using bio_set_op_attrs/bio_op.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 4e49ea4a3d block/fs/drivers: remove rw argument from submit_bio
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.

Signed-off-by: Mike Christie <mchristi@redhat.com>

Fixed up fs/ext4/crypto.c

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Jens Axboe c888a8f95a block: kill off q->flush_flags
Now that we converted everything to the newer block write cache
interface, kill off the queue flush_flags and queueable flush
entries.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-04-13 13:33:19 -06:00
Konrad Rzeszutek Wilk fa3184b898 xen/blback: Fit the important information of the thread in 17 characters
The processes names are truncated to 17, while we had the length
of the process as name 20 - which meant that while we filled
it out with various details - the last 3 characters (which had
the queue number) never surfaced to the user-space.

To simplify this and be able to fit the device name, domain id,
and the queue number we remove the 'blkback' from the name.

Prior to this patch the device name is "blkback.<domid>.<name>"
for example: blkback.8.xvda, blkback.11.hda.

With the multiqueue block backend we add "-%d" for the queue.
But sadly this is already way past the limit so it gets stripped.

Possible solution had been identified by Ian:
http://lists.xenproject.org/archives/html/xen-devel/2015-05/msg03516.html

  "
  If you are pressed for space then the "xvd" is probably a bit redundant
  in a string which starts blkbk.

  The guest may not even call the device xvdN (iirc BSD has another
  prefix) any how, so having blkback say so seems of limited use anyway.

  Since this seems to not include a partition number how does this work in
  the split partition scheme? (i.e. one where the guest is given xvda1 and
  xvda2 rather than xvda with a partition table)

[It will be 'blkback.8.xvda1', and 'blkback.11.xvda2']

  Perhaps something derived from one of the schemes in
  http://xenbits.xen.org/docs/unstable/misc/vbd-interface.txt might be a
  better fit?

After a bit of discussion (see
http://lists.xenproject.org/archives/html/xen-devel/2015-12/msg01588.html)
we settled on dropping the "blback" part.

This will make it possible to have the <domid>.<name>-<queue>:

 [1.xvda-0]
 [1.xvda-1]

And we enough space to make it go up to:

 [32100.xvdfg9-5]

Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-03-03 14:45:54 -07:00
Jan Beulich 5a7058450c xen-blkback: advertise indirect segment support earlier
There's no reason to defer this until the connect phase, and in fact
there are frontend implementations expecting this to be available
earlier. Move it into the probe function.

Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-03-03 14:45:53 -07:00
Linus Torvalds 641203549a Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
 "This is the block driver pull request for 4.5, with the exception of
  NVMe, which is in a separate branch and will be posted after this one.

  This pull request contains:

   - A set of bcache stability fixes, which have been acked by Kent.
     These have been used and tested for more than a year by the
     community, so it's about time that they got in.

   - A set of drbd updates from the drbd team (Andreas, Lars, Philipp)
     and Markus Elfring, Oleg Drokin.

   - A set of fixes for xen blkback/front from the usual suspects, (Bob,
     Konrad) as well as community based fixes from Kiri, Julien, and
     Peng.

   - A 2038 time fix for sx8 from Shraddha, with a fix from me.

   - A small mtip32xx cleanup from Zhu Yanjun.

   - A null_blk division fix from Arnd"

* 'for-4.5/drivers' of git://git.kernel.dk/linux-block: (71 commits)
  null_blk: use sector_div instead of do_div
  mtip32xx: restrict variables visible in current code module
  xen/blkfront: Fix crash if backend doesn't follow the right states.
  xen/blkback: Fix two memory leaks.
  xen/blkback: make st_ statistics per ring
  xen/blkfront: Handle non-indirect grant with 64KB pages
  xen-blkfront: Introduce blkif_ring_get_request
  xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule()
  xen/blkback: Free resources if connect_ring failed.
  xen/blocks: Return -EXX instead of -1
  xen/blkback: make pool of persistent grants and free pages per-queue
  xen/blkback: get the number of hardware queues/rings from blkfront
  xen/blkback: pseudo support for multi hardware queues/rings
  xen/blkback: separate ring information out of struct xen_blkif
  xen/blkfront: correct setting for xen_blkif_max_ring_order
  xen/blkfront: make persistent grants pool per-queue
  xen/blkfront: Remove duplicate setting of ->xbdev.
  xen/blkfront: Cleanup of comments, fix unaligned variables, and syntax errors.
  xen/blkfront: negotiate number of queues/rings to be used with backend
  xen/blkfront: split per device io_lock
  ...
2016-01-21 18:19:38 -08:00
Bob Liu 93bb277f97 xen/blkback: Fix two memory leaks.
This patch fixs two memleaks:
  backtrace:
    [<ffffffff817ba5e8>] kmemleak_alloc+0x28/0x50
    [<ffffffff81205e3b>] kmem_cache_alloc+0xbb/0x1d0
    [<ffffffff81534028>] xen_blkbk_probe+0x58/0x230
    [<ffffffff8146adb6>] xenbus_dev_probe+0x76/0x130
    [<ffffffff81511716>] driver_probe_device+0x166/0x2c0
    [<ffffffff815119bc>] __device_attach_driver+0xac/0xb0
    [<ffffffff8150fa57>] bus_for_each_drv+0x67/0x90
    [<ffffffff81511ab7>] __device_attach+0xc7/0x120
    [<ffffffff81511b23>] device_initial_probe+0x13/0x20
    [<ffffffff8151059a>] bus_probe_device+0x9a/0xb0
    [<ffffffff8150f0a1>] device_add+0x3b1/0x5c0
    [<ffffffff8150f47e>] device_register+0x1e/0x30
    [<ffffffff8146a9e8>] xenbus_probe_node+0x158/0x170
    [<ffffffff8146abaf>] xenbus_dev_changed+0x1af/0x1c0
    [<ffffffff8146b1bb>] backend_changed+0x1b/0x20
    [<ffffffff81468ca6>] xenwatch_thread+0xb6/0x160
unreferenced object 0xffff880007ba8ef8 (size 224):

  backtrace:
    [<ffffffff817ba5e8>] kmemleak_alloc+0x28/0x50
    [<ffffffff81205c73>] __kmalloc+0xd3/0x1e0
    [<ffffffff81534d87>] frontend_changed+0x2c7/0x580
    [<ffffffff8146af12>] xenbus_otherend_changed+0xa2/0xb0
    [<ffffffff8146b2c0>] frontend_changed+0x10/0x20
    [<ffffffff81468ca6>] xenwatch_thread+0xb6/0x160
    [<ffffffff810d3e97>] kthread+0xd7/0xf0
    [<ffffffff817c4a9f>] ret_from_fork+0x3f/0x70
    [<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff8800048dcd38 (size 224):

The first leak is caused by not put() the be->blkif reference
which we had gotten in xen_blkif_alloc(), while the second is
us not freeing blkif->rings in the right place.

Signed-off-by: Bob Liu <bob.liu@oracle.com>
Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04 12:21:26 -05:00
Bob Liu db6fbc1067 xen/blkback: make st_ statistics per ring
Make st_* statistics per ring and the VBD sysfs would iterate over all the
rings.

Note: xenvbd_sysfs_delif() is called in xen_blkbk_remove() before all rings
are torn down, so it's safe.

Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
v2: Aligned the variables on the same column.
2016-01-04 12:21:25 -05:00
Jiri Kosina a6e7af1288 xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule()
xen_blkif_schedule() kthread calls try_to_freeze() at the beginning of
every attempt to purge the LRU. This operation can't ever succeed though,
as the kthread hasn't marked itself as freezable.

Before (hopefully eventually) kthread freezing gets converted to fileystem
freezing, we'd rather mark xen_blkif_schedule() freezable (as it can
generate I/O during suspend).

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04 12:21:24 -05:00
Konrad Rzeszutek Wilk 2d0382fac1 xen/blkback: Free resources if connect_ring failed.
With the multi-queue support we could fail at setting up
some of the rings and fail the connection. That meant that
all resources tied to rings[0..n-1] (where n is the ring
that failed to be setup). Eventually the frontend will switch
to the states and we will call xen_blkif_disconnect.

However we do not want to be at the mercy of the frontend
deciding when to change states. This allows us to do the
cleanup right away and freeing resources.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04 12:21:07 -05:00
Konrad Rzeszutek Wilk bde21f73b9 xen/blocks: Return -EXX instead of -1
Lets return sensible values instead of -1.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04 12:21:07 -05:00
Bob Liu d4bf0065b7 xen/blkback: make pool of persistent grants and free pages per-queue
Make pool of persistent grants and free pages per-queue/ring instead of
per-device to get better scalability.

Test was done based on null_blk driver:
dom0: v4.2-rc8 16vcpus 10GB "modprobe null_blk"
domu: v4.2-rc8 16vcpus 10GB

[test]
rw=read
direct=1
ioengine=libaio
bs=4k
time_based
runtime=30
filename=/dev/xvdb
numjobs=16
iodepth=64
iodepth_batch=64
iodepth_batch_complete=64
group_reporting

Results:
iops1: After patch "xen/blkfront: make persistent grants per-queue".
iops2: After this patch.

Queues:			  1 	   4 	  	  8 	 	 16
Iops orig(k):		810 	1064 		780 		700
Iops1(k):		810     1230(~20%)	1024(~20%)	850(~20%)
Iops2(k):		810     1410(~35%)	1354(~75%)      1440(~100%)

With 4 queues after this commit we can get ~75% increase in IOPS, and
performance won't drop if increasing queue numbers.

Please find the respective chart in this link:
https://www.dropbox.com/s/agrcy2pbzbsvmwv/iops.png?dl=0

Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04 12:21:06 -05:00
Bob Liu d62d860003 xen/blkback: get the number of hardware queues/rings from blkfront
Backend advertises "multi-queue-max-queues" to front, also get the negotiated
number from "multi-queue-num-queues" written by blkfront.

Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04 12:21:06 -05:00
Konrad Rzeszutek Wilk 2fb1ef4f12 xen/blkback: pseudo support for multi hardware queues/rings
Preparatory patch for multiple hardware queues (rings). The number of
rings is unconditionally set to 1, larger number will be enabled in
"xen/blkback: get the number of hardware queues/rings from blkfront".

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
v2: Align variables in the structures.
2016-01-04 12:21:05 -05:00
Bob Liu 597957000a xen/blkback: separate ring information out of struct xen_blkif
Split per ring information to an new structure "xen_blkif_ring", so that one vbd
device can be associated with one or more rings/hardware queues.

Introduce 'pers_gnts_lock' to protect the pool of persistent grants since we
may have multi backend threads.

This patch is a preparation for supporting multi hardware queues/rings.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
v2: Align the variables in the structure.
2016-01-04 12:21:05 -05:00
Roger Pau Monné 1877914910 xen-blkback: read from indirect descriptors only once
Since indirect descriptors are in memory shared with the frontend, the
frontend could alter the first_sect and last_sect values after they have
been validated but before they are recorded in the request.  This may
result in I/O requests that overflow the foreign page, possibly
overwriting local pages when the I/O request is executed.

When parsing indirect descriptors, only read first_sect and last_sect
once.

This is part of XSA155.

CC: stable@vger.kernel.org
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:00:37 -05:00
Roger Pau Monné 1f13d75ccb xen-blkback: only read request operation from shared ring once
A compiler may load a switch statement value multiple times, which could
be bad when the value is in memory shared with the frontend.

When converting a non-native request to a native one, ensure that
src->operation is only loaded once by using READ_ONCE().

This is part of XSA155.

CC: stable@vger.kernel.org
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:00:32 -05:00
Julien Grall 9cce2914e2 xen/xenbus: Rename *RING_PAGE* to *RING_GRANT*
Linux may use a different page size than the size of grant. So make
clear that the order is actually in number of grant.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23 14:20:46 +01:00
Julien Grall 67de5dfbc1 block/xen-blkback: Make it running on 64KB page granularity
The PV block protocol is using 4KB page granularity. The goal of this
patch is to allow a Linux using 64KB page granularity behaving as a
block backend on a non-modified Xen.

It's only necessary to adapt the ring size and the number of request per
indirect frames. The rest of the code is relying on the grant table
code.

Note that the grant table code is allocating a Linux page per grant
which will result to waste 6OKB for every grant when Linux is using 64KB
page granularity. This could be improved by sharing the page between
multiple grants.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Acked-by: "Roger Pau Monné" <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23 14:20:40 +01:00
Jens Axboe adbe734b2a Merge branch 'stable/for-jens-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus
Konrad writes:

It has one fix that should go in and also be put in stable tree (I've
added the CC already).

It is a fix for a memory leak that can exposed via using UEFI
xen-blkfront driver.
2015-09-23 10:59:44 -06:00
Roger Pau Monne f929d42ceb xen/blkback: free requests on disconnection
This is due to  commit 86839c56de
"xen/block: add multi-page ring support"

When using an guest under UEFI - after the domain is destroyed
the following warning comes from blkback.

------------[ cut here ]------------
WARNING: CPU: 2 PID: 95 at
/home/julien/works/linux/drivers/block/xen-blkback/xenbus.c:274
xen_blkif_deferred_free+0x1f4/0x1f8()
Modules linked in:
CPU: 2 PID: 95 Comm: kworker/2:1 Tainted: G        W       4.2.0 #85
Hardware name: APM X-Gene Mustang board (DT)
Workqueue: events xen_blkif_deferred_free
Call trace:
[<ffff8000000890a8>] dump_backtrace+0x0/0x124
[<ffff8000000891dc>] show_stack+0x10/0x1c
[<ffff8000007653bc>] dump_stack+0x78/0x98
[<ffff800000097e88>] warn_slowpath_common+0x9c/0xd4
[<ffff800000097f80>] warn_slowpath_null+0x14/0x20
[<ffff800000557a0c>] xen_blkif_deferred_free+0x1f0/0x1f8
[<ffff8000000ad020>] process_one_work+0x160/0x3b4
[<ffff8000000ad3b4>] worker_thread+0x140/0x494
[<ffff8000000b2e34>] kthread+0xd8/0xf0
---[ end trace 6f859b7883c88cdd ]---

Request allocation has been moved to connect_ring, which is called every
time blkback connects to the frontend (this can happen multiple times during
a blkback instance life cycle). On the other hand, request freeing has not
been moved, so it's only called when destroying the backend instance. Due to
this mismatch, blkback can allocate the request pool multiple times, without
freeing it.

In order to fix it, move the freeing of requests to xen_blkif_disconnect to
restore the symmetry between request allocation and freeing.

Reported-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Julien Grall <julien.grall@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: xen-devel@lists.xenproject.org
CC: stable@vger.kernel.org # 4.2
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-09-23 12:09:19 -04:00
Linus Torvalds 1081230b74 Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "This first core part of the block IO changes contains:

   - Cleanup of the bio IO error signaling from Christoph.  We used to
     rely on the uptodate bit and passing around of an error, now we
     store the error in the bio itself.

   - Improvement of the above from myself, by shrinking the bio size
     down again to fit in two cachelines on x86-64.

   - Revert of the max_hw_sectors cap removal from a revision again,
     from Jeff Moyer.  This caused performance regressions in various
     tests.  Reinstate the limit, bump it to a more reasonable size
     instead.

   - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me.
     Most devices have huge trim limits, which can cause nasty latencies
     when deleting files.  Enable the admin to configure the size down.
     We will look into having a more sane default instead of UINT_MAX
     sectors.

   - Improvement of the SGP gaps logic from Keith Busch.

   - Enable the block core to handle arbitrarily sized bios, which
     enables a nice simplification of bio_add_page() (which is an IO hot
     path).  From Kent.

   - Improvements to the partition io stats accounting, making it
     faster.  From Ming Lei.

   - Also from Ming Lei, a basic fixup for overflow of the sysfs pending
     file in blk-mq, as well as a fix for a blk-mq timeout race
     condition.

   - Ming Lin has been carrying Kents above mentioned patches forward
     for a while, and testing them.  Ming also did a few fixes around
     that.

   - Sasha Levin found and fixed a use-after-free problem introduced by
     the bio->bi_error changes from Christoph.

   - Small blk cgroup cleanup from Viresh Kumar"

* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
  blk: Fix bio_io_vec index when checking bvec gaps
  block: Replace SG_GAPS with new queue limits mask
  block: bump BLK_DEF_MAX_SECTORS to 2560
  Revert "block: remove artifical max_hw_sectors cap"
  blk-mq: fix race between timeout and freeing request
  blk-mq: fix buffer overflow when reading sysfs file of 'pending'
  Documentation: update notes in biovecs about arbitrarily sized bios
  block: remove bio_get_nr_vecs()
  fs: use helper bio_add_page() instead of open coding on bi_io_vec
  block: kill merge_bvec_fn() completely
  md/raid5: get rid of bio_fits_rdev()
  md/raid5: split bio for chunk_aligned_read
  block: remove split code in blkdev_issue_{discard,write_same}
  btrfs: remove bio splitting and merge_bvec_fn() calls
  bcache: remove driver private bio splitting code
  block: simplify bio_add_page()
  block: make generic_make_request handle arbitrarily sized bios
  blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
  block: don't access bio->bi_error after bio_put()
  block: shrink struct bio down to 2 cache lines again
  ...
2015-09-02 13:10:25 -07:00
Christoph Hellwig 4246a0b63b block: add a bi_error field to struct bio
Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29 08:55:15 -06:00
Jens Axboe e162b219ae Merge branch 'stable/for-jens-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus
Konrad writes:

"There are three bugs that have been found in the xen-blkfront (and
backend). Two of them have the stable tree CC-ed. They have been found
where an guest is migrating to a host that is missing
'feature-persistent' support (from one that has it enabled). We end up
hitting an BUG() in the driver code."
2015-07-27 11:58:41 -06:00