rbd_img_obj_exists_submit() and rbd_img_obj_parent_read_full() are on
the writeback path for cloned images -- we attempt a stat on the parent
object to see if it exists and potentially read it in to call copyup.
GFP_NOIO should be used instead of GFP_KERNEL here.

Cc: stable@vger.kernel.org
Link: http://tracker.ceph.com/issues/22014Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NDavid Disseldorp <ddiss@suse.de>

  drivers/block/rbd.c: In function 'rbd_acquire_lock':
  drivers/block/rbd.c:3602:44: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Silence the warning, found it when built old kernel(3.10) with
OBS(opensuse build service).
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

bio_clone() makes a copy of the bi_io_vec, but rbd never changes that,
so there is no need for a copy.
bio_clone_fast() can be used instead, which avoids making the copy.

This requires that we provide a bio_set.  bio_clone() uses fs_bio_set,
but it isn't, in general, safe to use the same bio_set at different
levels of the stack, as that can lead to deadlocks.  As filesystems
use fs_bio_set, block devices shouldn't.

As rbd never stacks, it is safe to have a single global bio_set for
all rbd devices to use.  So allocate that when the module is
initialised, and use it with bio_clone_fast().
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use the same values for use for request completion errors as the return
value from ->queue_rq.  BLK_STS_RESOURCE is special cased to cause
a requeue, and all the others are completed as-is.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Commit 93c1defe ("rbd: remove the discard_zeroes_data flag")
explicitly didn't implement REQ_OP_WRITE_ZEROES for rbd, while the
following commit 48920ff2 ("block: remove the discard_zeroes_data
flag") dropped ->discard_zeroes_data in favor of REQ_OP_WRITE_ZEROES.

rbd does support efficient zeroing via CEPH_OSD_OP_ZERO opcode and will
release either some or all blocks depending on whether the zeroing
request is rbd_obj_bytes() aligned.  This is how we currently implement
discards, so REQ_OP_WRITE_ZEROES can be identical to REQ_OP_DISCARD for
now.  Caveats:

- REQ_NOUNMAP is ignored, but AFAICT that's true of at least two other
  current implementations - nvme and loop

- there is no ->write_zeroes_alignment and blk_bio_write_zeroes_split()
  is hence less helpful than blk_bio_discard_split(), but this can (and
  should) be fixed on the rbd side

In the future we will split these into two code paths to respect
REQ_NOUNMAP on zeroout and save on zeroing blocks that couldn't be
released on discard.

Fixes: 93c1defe ("rbd: remove the discard_zeroes_data flag")
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

CURRENT_TIME is not y2038 safe.  The macro will be deleted and all the
references to it will be replaced by ktime_get_* apis.

struct timespec is also not y2038 safe.  Retain timespec for timestamp
representation here as ceph uses it internally everywhere.  These
references will be changed to use struct timespec64 in a separate patch.

The current_fs_time() api is being changed to use vfs struct inode* as
an argument instead of struct super_block*.

Set the new mds client request r_stamp field using ktime_get_real_ts()
instead of using current_fs_time().

Also, since r_stamp is used as mtime on the server, use timespec_trunc()
to truncate the timestamp, using the right granularity from the
superblock.

This api will be transitioned to be y2038 safe along with vfs.

Link: http://lkml.kernel.org/r/1491613030-11599-5-git-send-email-deepa.kernel@gmail.comSigned-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
M:	Ilya Dryomov <idryomov@gmail.com>
M:	"Yan, Zheng" <zyan@redhat.com>
M:	Sage Weil <sage@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Support disabling automatic exclusive lock transfers to allow users
to be in charge of which node should own the lock while being able to
reuse exclusive lock's built-in blacklist/break-lock functionality.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Right now it's just 0, but "no automatic exclusive lock transfers" mode
code will need -EROFS.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Currently the exclusive lock is acquired only if the mapping is
writable, i.e. an image HEAD mapped in rw mode.  This means that we
don't acquire the lock for executing a read from a snapshot or an image
HEAD mapped in ro mode, even if lock_on_read is set.  This is somewhat
weird and inconsistent with "no automatic exclusive lock transfers"
mode, where the lock is acquired unconditionally.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

As we no longer release the lock before potentially raising BLACKLISTED
in rbd_reregister_watch(), the "either locked or blacklisted" assert in
rbd_queue_workfn() needs to go: we can be both locked and blacklisted
at that point now.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

In preparation for supporting set_cookie method (or rather set_cookie
fallback for older OSDs), store the lock cookie on lock and use it on
unlock instead of recalculating from rbd_dev->watch_cookie.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Currently the lock_state is set to UNLOCKED (preventing further I/O),
but RELEASED_LOCK notification isn't sent.  Be consistent with userspace
and treat ceph_cls_unlock() errors as the image is unlocked.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

add_disk() takes an extra reference on disk->queue, which is put in
put_disk() -> disk_release().  Avoiding blk_cleanup_queue() (which also
puts the queue) until add_disk() sets GENHD_FL_UP works for the queue
itself, but leaks various queue internals.  Conditioning tag_set freeing
on GENHD_FL_UP is wrong too: all error paths after rbd_init_disk() leak
the tag_set.

Move the final "announce" steps out of rbd_dev_device_setup() so that
it can be unwound like any other function.  Leave "announce" steps to
do_rbd_add/remove().
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

rbd_dev->disk tear down vs rbd_watch_cb() race shouldn't be a problem
anymore thanks to EXISTS and REMOVING checks in rbd_dev_update_size().
A similar race could occur on "rbd map", see commit 811c6688
("rbd: fix rbd map vs notify races").
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

... to simplify error handling in do_rbd_add().
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

No reason to hide CephFS-specific features in the rbd case.  Recent
feature bits mix RADOS and CephFS-specific stuff together anyway.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Remove the request_idx parameter, which can't be used safely now that we
support I/O schedulers with blk-mq.  Except for a superflous check in
mtip32xx it was unused anyway.

Also pass the tag_set instead of just the driver data - this allows drivers
to avoid some code duplication in a follow on cleanup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

rbd only supports discarding on large alignments, so the zeroing code
would always fall back to explicit writings of zeroes.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Constify all instances of blk_mq_ops, as they are never modified.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

... so that userspace can generate meaningful error messages and spell
out unsupported features that need to be disabled.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NSage Weil <sage@redhat.com>

CEPH_OSD_FLAG_ONDISK is set in account_request().
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

Declare device_type structure as const as it is only stored in the
type field of a device structure. This field is of type const, so add
const to the declaration of device_type structure.

File size before:
   text	   data	    bss	    dec	    hex	filename
  61546	  11610	    208	  73364	  11e94	drivers/block/rbd.o

File size after:
   text	   data	    bss	    dec	    hex	filename
  61610	  11578	    208	  73396	  11eb4	drivers/block/rbd.o
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

object_no can be trivially formatted into an object name.  We already
store object names in OSD requests with special care to avoid dynamic
allocations for short names.  Storing a name in obj_request, obtained
as below (!), is a waste and will be removed in the next commit.

    name = kmem_cache_alloc(rbd_segment_name_cache, ...);
    snprintf(name, ...);
    obj_request->object_name = kstrdup(name);
    kmem_cache_free(rbd_segment_name_cache, name);
    ...
    ceph_oid_aprintf(..., "%s", obj_request->object_name);
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

... and also fix up the comment -- format 1 data objects have always
been 12 hex digits long.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Factor OSD request allocation and initialization code out into
__rbd_osd_req_create().
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

The allocation doesn't depend on offset and length.  Both offset and
length can be changed after obj_request is allocated, too.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Add support for RBD_FEATURE_DATA_POOL feature.  rbd_dev->layout.pool_id
now stores the data pool id.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Rather than initializing layout fields with some made up values in
__rbd_dev_create(), move the initialization into rbd_init_layout() and
call it after the header is actually populated.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Returning u64 doesn't make sense: max header->obj_order is 25 and
ceph_file_layout::object_size is u32.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

As explained in the previous commit, rbd_obj_request machinery (and
rbd_osd_req_create() in particular) shouldn't be used for working with
metadata objects.

Switch to the recently added ceph_osdc_call().  It assumes single pages
for outbound and inbound buffers, but that's OK - none of the callers
need more than that.  These pages need to be allocated (messenger is in
dire need of proper iterator interface!), but we are swapping for
pages[] and pagelist allocations in the existing code.

Kill class_name argument - all rbd methods are under "rbd".
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

rbd_obj_request machinery is completely unnecessary here; all that's
being done is fetching a metadata object - no striping, cloning, etc.
More importantly, rbd_osd_req_create() grabs pool id from layout and
that is becoming a data pool id.

Kill offset argument - all metadata objects are small and read in full.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

No reason to delay it until image_id is known.  This will be required
by some rbd_obj_method_sync() callers, after rbd_obj_method_sync() is
changed to take oloc.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Image format 1 is deprecated and format 2 doesn't have these.  Also,
__rbd_dev_create() takes care of zeroing (or otherwise initializing)
format 2 specific fields.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJason Dillaman <dillaman@redhat.com>

We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Instead of keeping two levels of indirection for requests types, fold it
all into the operations.  The little caveat here is that previously
cmd_type only applied to struct request, while the request and bio op
fields were set to plain REQ_OP_READ/WRITE even for passthrough
operations.

Instead this patch adds new REQ_OP_* for SCSI passthrough and driver
private requests, althought it has to add two for each so that we
can communicate the data in/out nature of the request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>