This is the first of two patches aimed at isolating the code that
sets the mapping information into a single spot.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Add the size of the mapped image to the set of mapping-specific
fields in an rbd_device, and use it when setting the capacity of the
disk.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Several fields in a struct rbd_dev are related to what is mapped, as
opposed to the actual base rbd image.  If the base image is mapped
these are almost unneeded, but if a snapshot is mapped they describe
information about that snapshot.

In some contexts this can be a little bit confusing.  So group these
mapping-related field into a structure to make it clear what they
are describing.

This also includes a minor change that rearranges the fields in the
in-core image header structure so that invariant fields are at the
top, followed by those that change.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The "total_snaps" field in an rbd header structure is never any
different from the value of "num_snaps" stored within a snapshot
context.  Avoid any confusion by just using the value held within
the snapshot context, and get rid of the "total_snaps" field.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

A copy of rbd_dev->disk->queue is held in rbd_dev->q, but it's
never actually used.  So get just get rid of the field.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The name __rbd_init_snaps_header() doesn't really convey what that
function does very well.  Its purpose is to scan a new snapshot
context and either create or destroy snapshot device entries so
that local host's view is consistent with the reality maintained
on the OSDs.  This patch just changes the name of this function,
to be rbd_dev_snap_devs_update().  Still not perfect, but I think
better.

Also add some dynamic debug statements to this function.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

This should have been done as part of this commit:

    commit de71a297
    Author: Alex Elder <elder@inktank.com>
    Date:   Tue Jul 3 16:01:19 2012 -0500
    rbd: rename rbd_device->id

rbd_id_get() is assigning the rbd_dev->dev_id field.  Change the
name of that function as well as rbd_id_put() and rbd_id_max
to reflect what they are affecting.

Add some dynamic debug statements related to rbd device id activity.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Define rbd_assert() and use it in place of various BUG_ON() calls
now present in the code.  By default assertion checking is enabled;
we want to do this differently at some point.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There are two places where rbd_get_segment() is called.  One, in
rbd_rq_fn(), only needs to know the length within a segment that an
I/O request should be.  The other, in rbd_do_op(), also needs the
name of the object and the offset within it for the I/O request.

Split out rbd_segment_name() into three dedicated functions:
    - rbd_segment_name() allocates and formats the name of the
      object for a segment containing a given rbd image offset
    - rbd_segment_offset() computes the offset within a segment for
      a given rbd image offset
    - rbd_segment_length() computes the length to use for I/O within
      a segment for a request, not to exceed the end of a segment
      object.

In the new functions be a bit more careful, checking for possible
error conditions:
    - watch for errors or overflows returned by snprintf()
    - catch (using BUG_ON()) potential overflow conditions
      when computing segment length
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

It is possible in rbd_get_num_segments() for an overflow to occur
when adding the offset and length.  This is easily avoided.

Since the function returns an int and the one caller is already
prepared to handle errors, have it return -ERANGE if overflow would
occur.

The overflow check would not work if a zero-length request was
being tested, so short-circuit that case, returning 0 for the
number of segments required.  (This condition might be avoided
elsewhere already, I don't know.)

Have the caller end the request if either an error or 0 is returned.
The returned value is passed to __blk_end_request_all(), meaning
a 0 length request is not treated an error.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

There's a test for null rq pointer inside the while loop in
rbd_rq_fn() that's not needed.  That same test already occurred
in the immediatly preceding loop condition test.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

In bio_chain_clone(), at the end of the function the bi_next field
of the tail of the new bio chain is nulled.  This isn't necessary,
because if "tail" is non-null, its value will be the last bio
structure allocated at the top of the while loop in that function.
And before that structure is added to the end of the new chain, its
bi_next pointer is always made null.

While touching that function, clean a few other things:
    - define each local variable on its own line
    - move the definition of "tmp" to an inner scope
    - move the modification of gfpmask closer to where it's used
    - rearrange the logic that sets the chain's tail pointer
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

The "notify_timeout" rbd device option is never used, so get rid of
it.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

Add the ability to map an rbd image read-only, by specifying either
"read_only" or "ro" as an option on the rbd "command line."  Also
allow the inverse to be explicitly specified using "read_write" or
"rw".
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

The rbd options don't really apply to the ceph client.  So don't
store a pointer to it in the ceph_client structure, and put them
(a struct, not a pointer) into the rbd_dev structure proper.

Pass the rbd device structure to rbd_client_create() so it can
assign rbd_dev->rbdc if successful, and have it return an error code
instead of the rbd client pointer.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

This just rearranges things a bit more in rbd_header_from_disk()
so that the snapshot sizes are initialized right after the buffer
to hold them is allocated and doing a little further consolidation
that follows from that.  Also adds a few simple comments.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

The only thing the on-disk snap_names_len field is needed is to
size the buffer allocated to hold a copy of the snapshot names
for an rbd image.

So don't bother saving it in the in-core rbd_image_header structure.
Just use a local variable to hold the required buffer size while
it's needed.

Move the code that actually copies the snapshot names up closer
to where the required length is saved.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

In rbd_header_from_disk() the object prefix buffer is sized based on
the maximum size it's block_name equivalent on disk could be.

Instead, only allocate enough to hold null-terminated string from
the on-disk header--or the maximum size of no NUL is found.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

There is only caller of __rbd_client_find(), and it somewhat
clumsily gets the appropriate lock and gets a reference to the
existing ceph_client structure if it's found.

Instead, have that function handle its own locking, and acquire the
reference if found while it holds the lock.  Drop the underscores
from the name because there's no need to signify anything special
about this function.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>

This fixes a bug that went in with this commit:

    commit f6e0c99092cca7be00fca4080cfc7081739ca544
    Author: Alex Elder <elder@inktank.com>
    Date:   Thu Aug 2 11:29:46 2012 -0500
    rbd: simplify __rbd_init_snaps_header()

The problem is that a new rbd snapshot needs to go either after an
existing snapshot entry, or at the *end* of an rbd device's snapshot
list.  As originally coded, it is placed at the beginning.  This was
based on the assumption the list would be empty (so it wouldn't
matter), but in fact if multiple new snapshots are added to an empty
list in one shot the list will be non-empty after the first one is
added.

This addresses http://tracker.newdream.net/issues/3063Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

In the on-disk image header structure there is a field "block_name"
which represents what we now call the "object prefix" for an rbd
image.  Rename this field "object_prefix" to be consistent with
modern usage.

This appears to be the only remaining vestige of the use of "block"
in symbols that represent objects in the rbd code.

This addresses http://tracker.newdream.net/issues/1761Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>
Reviewed-by: NDan Mick <dan.mick@inktank.com>

Right now rbd_read_header() both reads the header object for an rbd
image and decodes its contents.  It does this repeatedly if needed,
in order to ensure a complete and intact header is obtained.

Separate this process into two steps--reading of the raw header
data (in new function, rbd_dev_v1_header_read()) and separately
decoding its contents (in rbd_header_from_disk()).  As a result,
the latter function no longer requires its allocated_snaps argument.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Add checks on the validity of the snap_count and snap_names_len
field values in rbd_dev_ondisk_valid().  This eliminates the
need to do them in rbd_header_from_disk().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The only caller of rbd_header_from_disk() is rbd_read_header().
It passes as allocated_snaps the number of snapshots it will
have received from the server for the snapshot context that
rbd_header_from_disk() is to interpret.  The first time through
it provides 0--mainly to extract the number of snapshots from
the snapshot context header--so that it can allocate an
appropriately-sized buffer to receive the entire snapshot
context from the server in a second request.

rbd_header_from_disk() will not fill in the array of snapshot ids
unless the number in the snapshot matches the number the caller
had allocated.

This patch adjusts that logic a little further to be more efficient.
rbd_read_header() doesn't even examine the snapshot context unless
the snapshot count (stored in header->total_snaps) matches the
number of snapshots allocated.  So rbd_header_from_disk() doesn't
need to allocate or fill in the snapshot context field at all in
that case.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

This just moves code around for the most part.  It was pulled out as
a separate patch to avoid cluttering up some upcoming patches which
are more substantive.  The point is basically to group everything
related to initializing the snapshot context together.

The only functional change is that rbd_header_from_disk() now
ensures the (in-core) header it is passed is zero-filled.  This
allows a simpler error handling path in rbd_header_from_disk().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Fix a few spots in rbd_header_from_disk() to use sizeof (object)
rather than sizeof (type).  Use a local variable to record sizes
to shorten some lines and improve readability.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Fix a number of spots where a pointer value that is known to
have become invalid but was not reset to null.

Also, toss in a change so we use sizeof (object) rather than
sizeof (type).
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The snap_names_len field of an rbd_image_header structure is defined
with type size_t.  That field is used as both the source and target
of 64-bit byte-order swapping operations though, so it's best to
define it with type u64 instead.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The purpose of __rbd_init_snaps_header() is to compare a new
snapshot context with an rbd device's list of existing snapshots.
It updates the list by adding any new snapshots or removing any
that are not present in the new snapshot context.

The code as written is a little confusing, because it traverses both
the existing snapshot list and the set of snapshots in the snapshot
context in reverse.  This was done based on an assumption about
snapshots that is not true--namely that a duplicate snapshot name
could cause an error in intepreting things if they were not
processed in ascending order.

These precautions are not necessary, because:
    - all snapshots are uniquely identified by their snapshot id
    - a new snapshot cannot be created if the rbd device has another
      snapshot with the same name
(It is furthermore not currently possible to rename a snapshot.)

This patch re-implements __rbd_init_snaps_header() so it passes
through both the existing snapshot list and the entries in the
snapshot context in forward order.  It still does the same thing
as before, but I find the logic considerably easier to understand.

By going forward through the names in the snapshot context, there
is no longer a need for the rbd_prev_snap_name() helper function.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

If a read-only rbd device is opened for writing in rbd_open(), it
returns without dropping the just-acquired device reference.

Fix this by moving the read-only check before getting the reference.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

In order for the network layer to see that AoE requires
no checksumming in a generic way, the packets must be
marked as requiring no checksum, so we make this requirement
explicit with the assertion.
Signed-off-by: NEd Cashin <ecashin@coraid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a command completes with a status of CMD_PROTOCOL_ERR, this
information should be conveyed to the SCSI mid layer, not dropped
on the floor.  Unlike a similar bug in the hpsa driver, this bug
only affects tape drives and CD and DVD ROM drives in the cciss
driver, and to induce it, you have to disconnect (or damage) a
cable, so it is not a very likely scenario (which would explain
why the bug has gone undetected for the last 10 years.)
Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fix a serious but uncommon bug in nbd which occurs when there is heavy
I/O going to the nbd device while, at the same time, a failure (server,
network) or manual disconnect of the nbd connection occurs.

There is a small window between the time that the nbd_thread is stopped
and the socket is shutdown where requests can continue to be queued to
nbd's internal waiting_queue.  When this happens, those requests are
never completed or freed.

The fix is to clear the waiting_queue on shutdown of the nbd device, in
the same way that the nbd request queue (queue_head) is already being
cleared.
Signed-off-by: NPaul Clements <paul.clements@steeleye.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current user_buffer check is incorrect and causes hdparm to fail

# hdparm -I /dev/rssda
 HDIO_DRIVE_CMD(identify) failed: Input/output error

/dev/rssda:

Patching linux-3.6-rc5 hdparm works as expected

# hdparm -I /dev/rssda
/dev/rssda:

ATA device, with non-removable media
	Model Number:       DELL_P320h-MTFDGAL350SAH
	Serial Number:      00000000121302025F01
	Firmware Revision:  B1442808
<snip>
Reported-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NDavid Milburn <dmilburn@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Removed the dead code in mtip_hw_read_registers() and mtip_hw_read_flags().

Reported-by: Coverity
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NSelvan Mani <smani@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Changed printk to be compliant with latest style changes
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NSelvan Mani <smani@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Proper reporting of write protect status on big-endian
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NSelvan Mani <smani@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Increased timeout for standby command to work with larger capacity drives
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NSelvan Mani <smani@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Return error for NCQ commands when the drive is in security locked state
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NSelvan Mani <smani@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Added supported device IDs in pci table
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NSelvan Mani <smani@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>