Currently each rbd device is allocated its own major number, which
leads to a hard limit of 230-250 images mapped at once.  This commit
adds support for a new single-major device number allocation scheme,
which is hidden behind a new single_major boolean module parameter and
is disabled by default for backwards compatibility reasons.  (Old
userspace cannot correctly unmap images mapped under single-major
scheme and would essentially just unmap a random image, if that.)

$ rbd showmapped
id pool image snap device
0  rbd  b100  -    /dev/rbd0
1  rbd  b101  -    /dev/rbd1
2  rbd  b102  -    /dev/rbd2
3  rbd  b103  -    /dev/rbd3

Old scheme (modprobe rbd):

$ ls -l /dev/rbd*
brw-rw---- 1 root disk 253, 0 Dec 10 12:24 /dev/rbd0
brw-rw---- 1 root disk 252, 0 Dec 10 12:28 /dev/rbd1
brw-rw---- 1 root disk 252, 1 Dec 10 12:28 /dev/rbd1p1
brw-rw---- 1 root disk 252, 2 Dec 10 12:28 /dev/rbd1p2
brw-rw---- 1 root disk 252, 3 Dec 10 12:28 /dev/rbd1p3
brw-rw---- 1 root disk 251, 0 Dec 10 12:28 /dev/rbd2
brw-rw---- 1 root disk 251, 1 Dec 10 12:28 /dev/rbd2p1
brw-rw---- 1 root disk 250, 0 Dec 10 12:24 /dev/rbd3

New scheme (modprobe rbd single_major=Y):

$ ls -l /dev/rbd*
brw-rw---- 1 root disk 253,   0 Dec 10 12:30 /dev/rbd0
brw-rw---- 1 root disk 253, 256 Dec 10 12:30 /dev/rbd1
brw-rw---- 1 root disk 253, 257 Dec 10 12:30 /dev/rbd1p1
brw-rw---- 1 root disk 253, 258 Dec 10 12:30 /dev/rbd1p2
brw-rw---- 1 root disk 253, 259 Dec 10 12:30 /dev/rbd1p3
brw-rw---- 1 root disk 253, 512 Dec 10 12:30 /dev/rbd2
brw-rw---- 1 root disk 253, 513 Dec 10 12:30 /dev/rbd2p1
brw-rw---- 1 root disk 253, 768 Dec 10 12:30 /dev/rbd3

(major 253 was assigned dynamically at module load time)

The new limit is 4096 images mapped at once, and it comes from the fact
that, as before, 256 minor numbers are reserved for each mapping.
(A follow-up commit changes the number of minors reserved and the way
we deal with partitions over that number.)

If single_major is set to true, two new sysfs interfaces show up:
/sys/bus/rbd/{add,remove}_single_major.  These are to be used instead
of /sys/bus/rbd/{add,remove}, which are disabled for backwards
compatibility reasons outlined above.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

In preparation for single-major device number allocation scheme, wire
up attribute_group::is_visible() callback for rbd bus.  This allows us
to make the new single-major attributes conditional.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Introduce /sys/bus/rbd/devices/<id>/minor sysfs attribute for exporting
rbd whole disk minor numbers.  This is a step towards single-major
device number allocation scheme, but also a good thing on its own.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Currently rbd ids are allocated using an atomic variable that keeps
track of the highest id currently in use and each new id is simply one
more than the value of that variable.  That's nice and cheap, but it
does mean that rbd ids are allowed to grow boundlessly, and, more
importantly, it's completely unpredictable.  So, in preparation for
single-major device number allocation scheme, which is going to
establish and rely on a constant mapping between rbd ids and device
numbers, switch to ida for rbd id assignments.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Refactor rbd_init() a bit to make it more clear what's going on.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Tweak "loaded" message, so that it looks like

[   30.184235] rbd: loaded

instead of

[   38.056564] rbd: loaded rbd (rados block device)

Also move (and slightly tweak) MODULE_DESCRIPTION so that all authors
are next to each other in modinfo output.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

rbd_device::dev_id is an int, format it as such.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

In the blkif_release function the bdget_disk() call might returns
a NULL ptr which might be dereferenced on bdev->bd_openers checking
Signed-off-by: NFelipe Pena <felipensp@gmail.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Added WARN per Roger's suggestion]

pfn cannot actually be used unless (!info->feature_persistent), nor is
pfn accessed in get_grant() unless (!info->feature_persistent), but silence
this warning anyway. gcc-4.8

drivers/block/xen-blkfront.c: In function 'do_blkif_request':
drivers/block/xen-blkfront.c:508:20: warning: 'pfn' may be used uninitialized in this function [-Wmaybe-uninitialized]
     gnt_list_entry = get_grant(&gref_head, pfn, info);
                    ^
drivers/block/xen-blkfront.c:492:19: note: 'pfn' was declared here
     unsigned long pfn;

Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NRoger Pau Monné <roger.pau@citrix.com>

Remove CONFIG_USE_GENERIC_SMP_HELPERS left by commit 0a06ff06
("kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS").
Signed-off-by: NYuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It isn't safe to call it without holding the vblk->vq_lock.
Reported-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NShaohua Li <shli@fusionio.com>

Fixed another condition of virtqueue_kick() not holding the lock.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use this new function to make code more comprehensible, since we are
reinitialzing the completion, not initializing.

[akpm@linux-foundation.org: linux-next resyncs]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Switch virtio-blk from the dual support for old-style requests and bios
to use the block-multiqueue.
Acked-by: NAsias He <asias@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

My static checker complains correctly that this is potential NULL
dereference because debugfs functions return NULL on error.  They return
an ERR_PTR if they are configured out.

We don't need to check for ERR_PTR because if debugfs is stubbed out the
dummy functions won't complain about that.  We don't need to check the
values before calling debugfs_remove() because that accepts ERR_PTRs and
NULL pointers.

We don't need to set pkt->dfs_f_info to NULL in pkt_debugfs_dev_new()
because it was initialized with kzalloc() so I have removed that.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

When persistent grants were added they were always used, even if the
backend doesn't have this feature (there's no harm in always using the
same set of pages). This restores the old data path when the backend
doesn't have persistent grants, removing the burden of doing a memcpy
when it is not actually needed.
Signed-off-by: NRoger Pau Monné <roger.pau@citrix.com>
Reported-by: NFelipe Franciosi <felipe.franciosi@citrix.com>
Cc: Felipe Franciosi <felipe.franciosi@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Fix up whitespace issues]

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Reorder placement of skd_construct(), skd_cons_sg_list(), skd_destruct()
and skd_free_sg_list() functions. Then remove no longer needed function
prototypes.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

skdev->pdev and skdev->pdev->bus are always different than NULL in
skd_do_inq_page_da() so simplify the code accordingly.

Also cache skdev->pdev value in pdev variable while at it.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

SKD_OMIT_FROM_SRC_DIST is never defined.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

skdev->pdev is set to pdev twice in skd_pci_probe(), first time
through skd_construct() call and the second time directly in
the function. Remove the second assignment as it is not needed.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use <asm/unaligned.h> instead of <asm-generic/unaligned.h>.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This is not a SCSI host driver so remove SCSI subsystem specific
includes.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Register block device in skd_pci_probe() instead of in skd_init() so it
is registered only if some devices are present (currently it is always
registered when the driver is loaded). Please note that this change
depends on the fact that register_blkdev(0, ...) never returns 0.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

* change priority level from KERN_INFO to KERN_ERR
* add "skd: " prefix
* do minor CodingStyle fixes

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

register_blkdev() is called before pci_register_driver() in skd_init()
so unregister_blkdev() should be called after pci_unregister_driver()
in skd_exit(). Fix it.

Cc: Akhil Bhansali <abhansali@stec-inc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove skd_flush_cmd structure and skd_flush_slab.
Remove skd_end_request wrapper around skd_end_request_blk.
Remove skd_requeue_request, use blk_requeue_request directly.
Cleanup some comments (remove "bio" info) and whitespace.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Just call the block functions directly, don't wrap them
in skd helpers. With only one queueing model enabled, there's
no point in doing that.

Also kill the ->start_time and ->bio from the skd_request_context,
we don't use those anymore.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The skd driver has a selectable rq or bio based queueing model.
For 3.14, we want to turn this into a single blk-mq interface
instead. With the immutable biovecs being merged in 3.13, the
bio model would need patches to even work. So rip it out, with
a conversion pending for blk-mq in the next release.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fix to return -ENOMEM in the skd construct error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

A return value of 1 is interpreted as an error
Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replaced DPRINTK() and VPRINTK() with pr_debug().
Signed-off-by: NRamprasad C <ramprasad.chinthekindi@hgst.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch fixes checkpatch.pl errors for assignment in if condition.
It also removes unused readq / readl function calls.

As Andrew had disabled the compilation of drivers for 32 bit,
I have modified format specifiers in few VPRINTKs to avoid warnings
during 64 bit compilation.
Signed-off-by: NAkhil Bhansali <abhansali@stec-inc.com>
Reviewed-by: NRamprasad Chinthekindi <rchinthekindi@stec-inc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch fixes a possible Kernel Panic on driver load if
the configuration on the card is messed up or not yet set.
The driver could possible give a 32 bit unsigned all Fs to
the kernel as the device's block size.

Now we only write the block size to the kernel if the
configuration from the card is valid.

Also, driver version is being updated.
Signed-off-by: NPhilip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch fixes a bug in which discards were always
calling pci_unmap_page. Discards should never call the
pci_unmap_page function call because they are never mapped.

This caused a race condition on PowerPC systems when issuing
discards, writes, and reads all at the same time. The
pci_map_page function would eventually map logical address
0 for a read or write. Discards are always assigned a DMA
address of 0 because they are never mapped. So if
pci_map_page mapped address 0 for a DMA and a discard was
"unmapped" then the address would be freed and would cause
an EEH event to occur when Hardware accesses the address.

This was injected/uncovered in commit:
b347f9cf0bc8d42ee95ba1d3837fd93045ab336b

The pci_dma_mapping_error function declares -1 a DMA_ERROR
not 0 like initially thought So before we would never unmap
discards because they were considered NULL.

This patch should fall on top of commit id:
fc1967bb08a6184ed44ef990e1dd4389901b809c

Also, the driver version is being up dated.
Signed-off-by: NPhilip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

For a long time, the receiving side has spread "too large" incoming
requests over multiple bios.  No need to shrink our max_bio_size
(max_hw_sectors) if the peer is reconfigured to use a different storage.

The problem manifests itself if we are not the top of the device stack
(DRBD is used a LVM PV).

A hardware reconfiguration on the peer may cause the supported
max_bio_size to shrink, and the connection handshake would now
unnecessarily shrink the max_bio_size on the active node.

There is no way to notify upper layers that they have to "re-stack"
their limits. So they won't notice at all, and may keep submitting bios
that are suddenly considered "too large for device".

We already check for compatibility and ignore changes on the peer,
the code only was masked out unless we have a fully established connection.
We just need to allow it a bit earlier during the handshake.

Also consider max_hw_sectors in our merge bvec function, just in case.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Symptoms: disconnect after bitmap exchange due to
bitmap overflow (e:49731075554) while decoding bm RLE packet

In the decoding step of the variable length integer run length encoding
there was potentially an uncatched bitshift by wordsize (variable >> 64).

The result of which is "undefined" :(
(only "sometimes" the result is the desired 0)

Fix: don't do any bit shift magic for shift == 64, just assign.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Online adding of new minors with freshly created meta data
to an resource with an established connection failed, with a
wrong state transition on one side on one side of the new minor.

Freshly created meta-data has a la_size (last agreed size) of 0.
When we online add such devices, the code wrongly got into
the code path for resyncing new storage that was added while
the disk was detached.

Fixed that by making the GREW from ZERO a special case.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Since drbd-8.4.0 it is possible to change the allow-two-primaries
network option while the connection is established.

The sequence code used to partially order packets from the
data socket with packets from the meta-data socket, still assued
that the allow-two-primaries option is constant while the
connection is established.

I.e.
On a node that has the RESOLVE_CONFLICTS bits set, after enabling
allow-two-primaries, when receiving the next data packet it timed out
while waiting for the necessary packets on the data socket to arrive
(wait_for_and_update_peer_seq() function).

Fixed that by always tracking the sequence number, but only waiting
for it if allow-two-primaries is set.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If we want to iterate over the (as of yet still empty) list in the
cleanup path, we need to initialize the list before the first goto fail.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>