Define a new rbd device flags field, manipulated using bit
operations. Replace the use of the current "exists" flag with a bit
in this new "flags" field. Add a little commentary about the
"exists" flag, which does not need to be manipulated atomically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When we register an osd request to linger, it means that request
will stay around (under control of the osd client) until we've
unregistered it. We do that for an rbd image's header object, and
we keep a pointer to the object request associated with it.
Keep a reference to the watch object request for as long as it is
registered to linger. Drop it again after we've removed the linger
registration.
This resolves:
http://tracker.ceph.com/issues/3937
(Note: this originally came about because the osd client was
issuing a callback more than once. But that behavior will be
changing soon, documented in tracker issue 3967.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Decrement the obj_request_count value when deleting an object
request from its image request's list. Rearrange a few lines
in the surrounding code.
This resolves:
http://tracker.ceph.com/issues/3940
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Switch to keeping track of the object request pointer rather than
the osd request used to watch the rbd image header object.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the code that unregisters an rbd device's lingering header
object watch request into rbd_dev_header_watch_sync(), so it
occurs in the same function that originally sets up that request.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Get rid rbd_req_sync_exec() because it is no longer used. That
eliminates the last use of rbd_req_sync_op(), so get rid of that
too. And finally, that leaves rbd_do_request() unreferenced, so get
rid of that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reimplement synchronous object method calls using the new request
tracking code. Use the name rbd_obj_method_sync()
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When we receive notification of a change to an rbd image's header
object we need to refresh our information about the image (its
size and snapshot context). Once we have refreshed our rbd image
we need to acknowledge the notification.
This acknowledgement was previously done synchronously, but there's
really no need to wait for it to complete.
Change it so the caller doesn't wait for the notify acknowledgement
request to complete. And change the name to reflect it's no longer
synchronous.
This resolves:
http://tracker.newdream.net/issues/3877
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Get rid rbd_req_sync_notify_ack() because it is no longer used.
As a result rbd_simple_req_cb() becomes unreferenced, so get rid
of that too.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Use the new object request tracking mechanism for handling a
notify_ack request.
Move the callback function below the definition of this so we don't
have to do a pre-declaration.
This resolves:
http://tracker.newdream.net/issues/3754
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Get rid of rbd_req_sync_watch(), because it is no longer used.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Implement a new function to set up or tear down a watch event
for an mapped rbd image header using the new request code.
Create a new object request type "nodata" to handle this. And
define rbd_osd_trivial_callback() which simply marks a request done.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Delete rbd_req_sync_read() is no longer used, so get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reimplement the synchronous read operation used for reading a
version 1 header using the new request tracking code. Name the
resulting function rbd_obj_read_sync() to better reflect that
it's a full object operation, not an object request. To do this,
implement a new OBJ_REQUEST_PAGES object request type.
This implements a new mechanism to allow the caller to wait for
completion for an rbd_obj_request by calling rbd_obj_request_wait().
This partially resolves:
http://tracker.newdream.net/issues/3755
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The two remaining callers of rbd_do_request() always pass a null
collection pointer, so the "coll" and "coll_index" parameters are
not needed. There is no other use of that data structure, so it
can be eliminated.
Deleting them means there is no need to allocate a rbd_request
structure for the callback function. And since that's the only use
of *that* structure, it too can be eliminated.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Now that the request function has been replaced by one using the new
request management data structures the old one can go away.
Deleting it makes rbd_dev_do_request() no longer needed, and
deleting that makes other functions unneeded, and so on.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This patch fully implements the new request tracking code for rbd
I/O requests.
Each I/O request to an rbd image will get an rbd_image_request
structure allocated to track it. This provides access to all
information about the original request, as well as access to the
set of one or more object requests that are initiated as a result
of the image request.
An rbd_obj_request structure defines a request sent to a single osd
object (possibly) as part of an rbd image request. An rbd object
request refers to a ceph_osd_request structure built up to represent
the request; for now it will contain a single osd operation. It
also provides space to hold the result status and the version of the
object when the osd request completes.
An rbd_obj_request structure can also stand on its own. This will
be used for reading the version 1 header object, for issuing
acknowledgements to event notifications, and for making object
method calls.
All rbd object requests now complete asynchronously with respect
to the osd client--they supply a common callback routine.
This resolves:
http://tracker.newdream.net/issues/3741
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When an rbd image is initially mapped a watch event is registered so
we can do something if the header object changes.
The code that does this currently loops if initiating the watch
request results in an ERANGE error. The osds will never return
ERANGE, so there's no reason to do this loop, so get rid of it.
This resolves:
http://tracker.newdream.net/issues/3860
Note that the problem this loop was intended to solve is a race
between collecting image header information and setting up the watch
on the header object. The real fix for that problem is described
here:
http://tracker.newdream.net/issues/3871
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The return type of rbd_get_num_segments() is int, but the values it
operates on are u64. Although it's not likely, there's no guarantee
the result won't exceed what can be respresented in an int. The
function is already designed to return -ERANGE on error, so just add
this possible overflow as another reason to return that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
A few very minor changes to the rbd code:
- RBD_MAX_OPT_LEN is unused, so get rid of it
- Consolidate rbd options definitions
- Make rbd_segment_name() return pointer to const char
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The type of the snap_id local variable is defined with the
wrong byte order. Fix that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Both rbd_req_sync_op() and rbd_do_request() have a "linger"
parameter, which is the address of a pointer that should refer to
the osd request structure used to issue a request to an osd.
Only one case ever supplies a non-null "linger" argument: an
CEPH_OSD_OP_WATCH start. And in that one case it is assigned
&rbd_dev->watch_request.
Within rbd_do_request() (where the assignment ultimately gets made)
we know the rbd_dev and therefore its watch_request field. We
also know whether the op being sent is CEPH_OSD_OP_WATCH start.
Stop opaquely passing down the "linger" pointer, and instead just
assign the value directly inside rbd_do_request() when it's needed.
This makes it unnecessary for rbd_req_sync_watch() to make
arrangements to hold a value that's not available until a
bit later. This more clearly separates setting up a watch
request from submitting it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The two remaining osd ops used by rbd are CEPH_OSD_OP_WATCH and
CEPH_OSD_OP_NOTIFY_ACK. Move the setup of those operations into
rbd_osd_req_op_create(), and get rid of rbd_create_rw_op() and
rbd_destroy_op().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the initialization of the CEPH_OSD_OP_CALL operation into
rbd_osd_req_op_create().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the assignment of the extent offset and length and payload
length out of rbd_req_sync_op() and into its caller in the one spot
where a read (and note--no write) operation might be initiated.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_do_request() there's a sort of last-minute assignment of the
extent offset and length and payload length for read and write
operations. Move those assignments into the caller (in those spots
that might initiate read or write operations)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When rbd_req_sync_notify_ack() calls rbd_do_request() it supplies
rbd_simple_req_cb() as its callback function. Because the callback
is supplied, an rbd_req structure gets allocated and populated so it
can be used by the callback. However rbd_simple_req_cb() is not
freeing (or even using) the rbd_req structure, so it's getting
leaked.
Since rbd_simple_req_cb() has no need for the rbd_req structure,
just avoid allocating one for this case. Of the three calls to
rbd_do_request(), only the one from rbd_do_op() needs the rbd_req
structure, and that call can be distinguished from the other two
because it supplies a non-null rbd_collection pointer.
So fix this leak by only allocating the rbd_req structure if a
non-null "coll" value is provided to rbd_do_request().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When rbd_do_request() is called it allocates and populates an
rbd_req structure to hold information about the osd request to be
sent. This is done for the benefit of the callback function (in
particular, rbd_req_cb()), which uses this in processing when
the request completes.
Synchronous requests provide no callback function, in which case
rbd_do_request() waits for the request to complete before returning.
This case is not handling the needed free of the rbd_req structure
like it should, so it is getting leaked.
Note however that the synchronous case has no need for the rbd_req
structure at all. So rather than simply freeing this structure for
synchronous requests, just don't allocate it to begin with.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The rbd_req_sync_watch() and rbd_req_sync_unwatch() functions are
nearly identical. Combine them into a single function with a flag
indicating whether a watch is to be initiated or torn down.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Each osd message includes a layout structure, and for rbd it is
always the same (at least for osd's in a given pool).
Initialize a layout structure when an rbd_dev gets created and just
copy that into osd requests for the rbd image.
Replace an assertion that was done when initializing the layout
structures with code that catches and handles anything that would
trigger the assertion as soon as it is identified. This precludes
that (bad) condition from ever occurring.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When rbd_do_request() has a request to process it initializes a ceph
file layout structure and uses it to compute offsets and limits for
the range of the request using ceph_calc_file_object_mapping().
The layout used is fixed, and is based on RBD_MAX_OBJ_ORDER (30).
It sets the layout's object size and stripe unit to be 1 GB (2^30),
and sets the stripe count to be 1.
The job of ceph_calc_file_object_mapping() is to determine which
of a sequence of objects will contain data covered by range, and
within that object, at what offset the range starts. It also
truncates the length of the range at the end of the selected object
if necessary.
This is needed for ceph fs, but for rbd it really serves no purpose.
It does its own blocking of images into objects, echo of which is
(1 << obj_order) in size, and as a result it ignores the "bno"
value returned by ceph_calc_file_object_mapping(). In addition,
by the point a request has reached this function, it is already
destined for a single rbd object, and its length will not exceed
that object's extent. Because of this, and because the mapping will
result in blocking up the range using an integer multiple of the
image's object order, ceph_calc_file_object_mapping() will never
change the offset or length values defined by the request.
In other words, this call is a big no-op for rbd data requests.
There is one exception. We read the header object using this
function, and in that case we will not have already limited the
request size. However, the header is a single object (not a file or
rbd image), and should not be broken into pieces anyway. So in fact
we should *not* be calling ceph_calc_file_object_mapping() when
operating on the header object.
So...
Don't call ceph_calc_file_object_mapping() in rbd_do_request(),
because useless for image data and incorrect to do sofor the image
header.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This patch gets rid of rbd_calc_raw_layout() by simply open coding
it in its one caller.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This is the first in a series of patches aimed at eliminating
the use of ceph_calc_raw_layout() by rbd.
It simply pulls in a copy of that function and renames it
rbd_calc_raw_layout().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
We now know that every of rbd_req_sync_op() passes an array of
exactly one operation, as evidenced by all callers passing 1 as its
num_op argument. So get rid of that argument, assuming a single op.
Similarly, we now know that all callers of rbd_do_request() pass 1
as the num_op value, so that parameter can be eliminated as well.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Throughout the rbd code there are spots where it appears we can
handle an osd request containing more than one osd request op.
But that is only the way it appears. In fact, currently only one
operation at a time can be supported, and supporting more than
one will require much more than fleshing out the support that's
there now.
This patch changes names to make it perfectly clear that anywhere
we're dealing with a block of ops, we're in fact dealing with
exactly one of them. We'll be able to simplify some things as
a result.
When multiple op support is implemented, we can update things again
accordingly.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Both ceph_osdc_alloc_request() and ceph_osdc_build_request() are
provided an array of ceph osd request operations. Rather than just
passing the number of operations in the array, the caller is
required append an additional zeroed operation structure to signal
the end of the array.
All callers know the number of operations at the time these
functions are called, so drop the silly zero entry and supply that
number directly. As a result, get_num_ops() is no longer needed.
This also means that ceph_osdc_alloc_request() never uses its ops
argument, so that can be dropped.
Also rbd_create_rw_ops() no longer needs to add one to reserve room
for the additional op.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add a num_op parameter to rbd_do_request() and rbd_req_sync_op() to
indicate the number of entries in the array. The callers of these
functions always know how many entries are in the array, so just
pass that information down.
This is in anticipation of eliminating the extra zero-filled entry
in these ops arrays.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Only one of the two callers of ceph_osdc_alloc_request() provides
page or bio data for its payload. And essentially all that function
was doing with those arguments was assigning them to fields in the
osd request structure.
Simplify ceph_osdc_alloc_request() by having the caller take care of
making those assignments
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The only thing ceph_osdc_alloc_request() really does with the
flags value it is passed is assign it to the newly-created
osd request structure. Do that in the caller instead.
Both callers subsequently call ceph_osdc_build_request(), so have
that function (instead of ceph_osdc_alloc_request()) issue a warning
if a request comes through with neither the read nor write flags set.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The osdc parameter to ceph_calc_raw_layout() is not used, so get rid
of it. Consequently, the corresponding parameter in calc_layout()
becomes unused, so get rid of that as well.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
A snapshot id must be provided to ceph_calc_raw_layout() even though
it is not needed at all for calculating the layout.
Where the snapshot id *is* needed is when building the request
message for an osd operation.
Drop the snapid parameter from ceph_calc_raw_layout() and pass
that value instead in ceph_osdc_build_request().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The len argument to ceph_osdc_build_request() is set up to be
passed by address, but that function never updates its value
so there's no need to do this. Tighten up the interface by
passing the length directly.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
For some reason, the snapid field of the osd request header is
explicitly set to CEPH_NOSNAP in rbd_do_request(). Just a few lines
later--with no code that would access this field in between--a call
is made to ceph_calc_raw_layout() passing the snapid provided to
rbd_do_request(), which encodes the snapid value it is provided into
that field instead.
In other words, there is no need to fill in CEPH_NOSNAP, and doing
so suggests it might be necessary. Don't do that any more.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The snapc and snapid parameters to rbd_req_sync_op() always take
the values NULL and CEPH_NOSNAP, respectively. So just get rid
of them and use those values where needed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
All callers of rbd_req_sync_exec() pass CEPH_OSD_FLAG_READ as their
flags argument. Delete that parameter and use CEPH_OSD_FLAG_READ
within the function. If we find a need to support write operations
we can add it back again.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is only one caller of rbd_req_sync_read(), and it passes
CEPH_NOSNAP as the snapshot id argument. Delete that parameter
and just use CEPH_NOSNAP within the function.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The last two parameters to ceph_osd_build_request() describe the
object id, but the values passed always come from the osd request
structure whose address is also provided. Get rid of those last
two parameters.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Pull a block of code that initializes the layout structure in an osd
request into its own function so it can be reused.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Right now we get the snapshot context for an rbd image (under
protection of the header semaphore) for every request processed.
There's no need to get the snap context if we're doing a read,
so avoid doing so in that case.
Note that we no longer need to hold the header semaphore to
check the rbd_dev's existence flag.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The rbd_device->exists field can be updated asynchronously, changing
from set to clear if a mapped snapshot disappears from the base
image's snapshot context.
Currently, value of the "exists" flag is only read and modified
under protection of the header semaphore, but that will change with
the next patch. Making it atomic ensures this won't be a problem
because the a the non-existence of device will be immediately known.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Now that a big hunk in the middle of rbd_rq_fn() has been moved
into its own routine we can simplify it a little more.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Only one of the three callers of rbd_do_request() provide a
collection structure to aggregate status.
If an error occurs in rbd_do_request(), have the caller
take care of calling rbd_coll_end_req() if necessary in
that one spot.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_rq_fn(), requests are fetched from the block layer and each
request is processed, looping through the request's list of bio's
until they've all been consumed.
Separate the handling for a single request into its own function to
make it a bit easier to see what's going on.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The result field in a ceph osd reply header is a signed 32-bit type,
but rbd code often casually uses int to represent it.
The following changes the types of variables that handle this result
value to be "s32" instead of "int" to be completely explicit about
it. Only at the point we pass that result to __blk_end_request()
does the type get converted to the plain old int defined for that
interface.
There is almost certainly no binary impact of this change, but I
prefer to show the exact size and signedness of the value since we
know it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
There are spots where a ceph_osds_request pointer variable is given
the name "req". Since we're dealing with (at least) three types of
requests (block layer, rbd, and osd), I find this slightly
distracting.
Change such instances to use "osd_req" consistently to make the
abstraction represented a little more obvious.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There are two names used for items of rbd_request structure type:
"req" and "req_data". The former name is also used to represent
items of pointers to struct ceph_osd_request.
Change all variables that have these names so they are instead
called "rbd_req" consistently.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Josh suggested adding warnings to this function to help users
diagnose problems.
Other than memory allocatino errors, there are two places where
errors can be returned. Both represent problems that should
have been caught earlier, and as such might well have been
handled with BUG_ON() calls. But if either ever did manage to
happen, it will be reported.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add a warning in bio_chain_clone_range() to help a user determine
what exactly might have led to a failure. There is only one; please
say something if you disagree with the following reasoning.
There are three places this can return abnormally:
- Initially, if there is nothing to clone. It turns out that
right now this cannot happen anyway. The test is in place
because the code below it doesn't work if those conditions
don't hold. As such they could be assertions but since I can
return a null to indicate an error I just do that instead.
I have not added a warning here because it won't happen.
- While processing bio's, if none remain but there are supposed
to be more bytes to clone. Here I have added a warning.
- If bio_clone_range() returns a null pointer. That function
will have already produced a warning (at least the first
time, via WARN_ON_ONCE()) to distinguish the cause of the
error. The only exception is memory exhaustion, and I'd
rather not pepper the code with warnings in all those spots.
So no warning is added in that place.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Tell the user (via dmesg) what was wrong with the arguments provided
via /sys/bus/rbd/add.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Define a new function rbd_warn() that produces a boilerplate warning
message, identifying in the resulting message the affected rbd
device in the best way available. Use it in a few places that now
use pr_warning().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This replaces two kmalloc()/memcpy() combinations with a single
call to kmemdup().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no real benefit to keeping the length of an image id, so
get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There may have been a benefit to hanging on to the length of an
image name before, but there is really none now. The only time it's
used is when probing for rbd images, so we can just compute the
length then.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
I promised Josh I would document whether there were any restrictions
needed for accessing fields of an rbd_spec structure. This adds a
big block of comments that documents the structure and how it is
used--including the fact that we don't attempt to synchronize access
to it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The functions rbd_get_dev() and rbd_put_dev() are trivial wrappers
that add no value, and their existence suggests they may do more
than what they do.
Get rid of them.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
ENOTSUPP is not a standard errno (it shows up as "Unknown error 524"
in an error message). This is what was getting produced when the
the local rbd code does not implement features required by a
discovered rbd image.
Change the error code returned in this case to ENXIO.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
RBD_MAX_SEG_NAME_LEN represents the maximum length of an rbd object
name (i.e., one of the objects providing storage backing an rbd
image).
Another symbol, MAX_OBJ_NAME_SIZE, is used in the osd client code to
define the maximum length of any object name in an osd request.
Right now they disagree, with RBD_MAX_SEG_NAME_LEN being too big.
There's no real benefit at this point to defining the rbd object
name length limit separate from any other object name, so just
get rid of RBD_MAX_SEG_NAME_LEN and use MAX_OBJ_NAME_SIZE in its
place.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
There is no check in rbd_remove() to see if anybody holds open the
image being removed. That's not cool.
Add a simple open count that goes up and down with opens and closes
(releases) of the device, and don't allow an rbd image to be removed
if the count is non-zero.
Protect the updates of the open count value with ctl_mutex to ensure
the underlying rbd device doesn't get removed while concurrently
being opened.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
When a layered rbd image has a parent, that parent is identified
only by its pool id, image id, and snapshot id. Images that have
been mapped also record *names* for those three id's.
Add code to look up these names for parent images so they match
mapped images more closely. Skip doing this for an image if it
already has its pool name defined (this will be the case for images
mapped by the user).
It is possible that an the name of a parent image can't be
determined, even if the image id is valid. If this occurs it
does not preclude correct operation, so don't treat this as
an error.
On the other hand, defined pools will always have both an id and a
name. And any snapshot of an image identified as a parent for a
clone image will exist, and will have a name (if not it indicates
some other internal error). So treat failure to get these bits
of information as errors.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add support for getting the the information identifying the parent
image for rbd images that have them. The child image holds a
reference to its parent image specification structure. Create a new
entry "parent" in /sys/bus/rbd/image/N/ to report the identifying
information for the parent image, if any.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Format 2 parent images are partially identified by their image id,
but it may not be possible to determine their image name. The name
is not strictly needed for correct operation, so we won't be
treating it as an error if we don't know it. Handle this case
gracefully in rbd_name_show().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
We will know the image id for format 2 parent images, but won't
initially know its image name. Avoid making the query for an image
id in rbd_dev_image_id() if it's already known.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Group the activities that now take place after an rbd_dev_probe()
call into a single function, and move the call to that function
into rbd_dev_probe() itself.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Encapsulate the creation/initialization and destruction of rbd
device structures. The rbd_client and the rbd_spec structures
provided on creation hold references whose ownership is transferred
to the new rbd_device structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Group the allocation and initialization of fields of the rbd device
structure created in rbd_add(). Move the grouped code down later in
the function, just prior to the call to rbd_dev_probe(). This is
for the most part simple code movement.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The only reason rbd_dev is passed to rbd_get_client() is so its
rbd_client field can get assigned. Instead, just return the
rbd_client pointer as a result and have the caller do the
assignment.
Change rbd_put_client() so it takes an rbd_client structure,
so follows the more typical symmetry with rbd_get_client().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Pass the address of an rbd_spec structure to rbd_add_parse_args().
Use it to hold the information defining the rbd image to be mapped
in an rbd_add() call.
Use the result in the caller to initialize the rbd_dev->id field.
This means rbd_dev is no longer needed in rbd_add_parse_args(),
so get rid of it.
Now that this transformation of rbd_add_parse_args() is complete,
correct and expand on the its header documentation to reflect the
new reality.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
With layered images we'll share rbd_spec structures, so add a
reference count to it. It neatens up some code also.
A silly get/put pair is added to the alloc routine just to avoid
"defined but not used" warnings. It will go away soon.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Group the fields that uniquely specify an rbd image into a new
reference-counted rbd_spec structure. This structure will be used
to describe the desired image when mapping an image, and when
probing parent images in layered rbd devices. Replace the set of
fields in the rbd device structure with a pointer to a dynamically
allocated rbd_spec.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Change the interface to rbd_add_parse_args() so it returns an
error code rather than a pointer. Return the ceph_options result
via a pointer whose address is passed as an argument.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Have the caller pass the address of an rbd_options structure to
rbd_add_parse_args(), to be initialized with the information
gleaned as a result of the parse.
I know, this is another near-reversal of a recent change...
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The snapshot name returned by rbd_add_parse_args() just gets saved
in the rbd_dev eventually. So just do that inside that function and
do away with the snap_name argument, both in rbd_add_parse_args()
and rbd_dev_set_mapping().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
They "options" argument to rbd_add_parse_args() (and it's partner
options_size) is now only needed within the function, so there's no
need to have the caller allocate and pass the options buffer. Just
allocate the options buffer within the function using dup_token().
Also distinguish between failures due to failed memory allocation
and failing because a required argument was missing.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The value returned in the "snap_name_len" argument to
rbd_add_parse_args() is never actually used, so get rid of it.
The snap_name_len recorded in rbd_dev_v2_snap_name() is not
useful either, so get rid of that too.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This patch makes rbd_add_parse_args() be the single place all
argument parsing occurs for an image map request:
- Move the ceph_parse_options() call into that function
- Use local variables rather than parameters to hold the list
of monitor addresses supplied
- Rather than returning it, pass the snapshot name (and its
length) back via parameters
- Have the function return a ceph_options structure pointer
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move option parsing out of rbd_get_client() and into its caller.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
A Boolean field "snap_exists" in an rbd mapping is used to indicate
whether a mapped snapshot has been removed from an image's snapshot
context, to stop sending requests for that snapshot as soon as we
know it's gone.
Generalize the interpretation of this field so it applies to
non-snapshot (i.e. "head") mappings. That is, define its value
to be false until the mapping has been set, and then define it to be
true for both snapshot mappings or head mappings.
Rename the field "exists" to reflect the broader interpretation.
The rbd_mapping structure is on its way out, so move the field
back into the rbd_device structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Moving the snap_id and snap_name fields into the separate
rbd_mapping structure was misguided. (And in time, perhaps
we'll do away with that structure altogether...)
Move these fields back into struct rbd_device.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
If a format 2 image has a parent, its pool id will be specified
using a 64-bit value. Change the pool id we save for an image to
match that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
If rbd_dev_snaps_update() has ever been called for an rbd device
structure there could be snapshot structures on its snaps list.
In rbd_add(), this function is called but a subsequent error
path neglected to clean up any of these snapshots.
Add a call to rbd_remove_all_snaps() in the appropriate spot to
remedy this. Change a couple of error labels to be a little
clearer while there.
Drop the leading underscores from the function name; there's nothing
special about that function that they might signify. As suggested
in review, the leading underscores in __rbd_remove_snap_dev() have
been removed as well.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When processing a request, rbd_rq_fn() makes clones of the bio's in
the request's bio chain and submits the results to osd's to be
satisfied. If a request bio straddles the boundary between objects
backing the rbd image, it must be represented by two cloned bio's,
one for the first part (at the end of one object) and one for the
second (at the beginning of the next object).
This has been handled by a function bio_chain_clone(), which
includes an interface only a mother could love, and which has
been found to have other problems.
This patch defines two new fairly generic bio functions (one which
replaces bio_chain_clone()) to help out the situation, and then
revises rbd_rq_fn() to make use of them.
First, bio_clone_range() clones a portion of a single bio, starting
at a given offset within the bio and including only as many bytes
as requested. As a convenience, a request to clone the entire bio
is passed directly to bio_clone().
Second, bio_chain_clone_range() performs a similar function,
producing a chain of cloned bio's covering a sub-range of the
source chain. No bio_pair structures are used, and if successful
the result will represent exactly the specified range.
Using bio_chain_clone_range() makes bio_rq_fn() a little easier
to understand, because it avoids the need to pass very much
state information between consecutive calls. By avoiding the need
to track a bio_pair structure, it also eliminates the problem
described here: http://tracker.newdream.net/issues/2933
Note that a block request (and therefore the complete length of
a bio chain processed in rbd_rq_fn()) is an unsigned int, while
the result of rbd_segment_length() is u64. This change makes
this range trunctation explicit, and trips a bug if the the
segment boundary is too far off.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The rbd_device structure has an embedded rbd_options structure.
Such a structure is needed to work with the generic ceph argument
parsing code, but there's no need to keep it around once argument
parsing is done.
Use a local variable to hold the rbd options used in parsing in
rbd_get_client(), and just transfer its content (it's just a
read_only flag) into the field in the rbd_mapping sub-structure
that requires that information.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
The aim of this patch is to make what's going on rbd_merge_bvec() a
bit more obvious than it was before. This was an issue when a
recent btrfs bug led us to question whether the merge function was
working correctly.
Use "obj" rather than "chunk" to indicate the units whose boundaries
we care about we call (rados) "objects".
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Change RBD_MAX_SNAP_NAME_LEN to be based on NAME_MAX. That is a
practical limit for the length of a snapshot name (based on the
presence of a directory using the name under /sys/bus/rbd to
represent the snapshot).
The /sys entry is created by prefixing it with "snap_"; define that
prefix symbolically, and take its length into account in defining
the snapshot name length limit.
Enforce the limit in rbd_add_parse_args(). Also delete a dout()
call in that function that was not meant to be committed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This adds a verification that an rbd image's object order is
within the upper and lower bounds supported by this implementation.
It must be at least 9 (SECTOR_SHIFT), because the Linux bio system
assumes that minimum granularity.
It also must be less than 32 (at the moment anyway) because there
exist spots in the code that store the size of a "segment" (object
backing an rbd image) in a signed int variable, which can be 32 bits
including the sign. We should be able to relax this limit once
we've verified the code uses 64-bit types where needed.
Note that the CLI tool already limits the order to the range 12-25.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The two calls to rbd_do_op() from rbd_rq_fn() differ only in the
value passed for the snapshot id and the snapshot context.
For reads the snapshot always comes from the mapping, and for writes
the snapshot id is always CEPH_NOSNAP.
The snapshot context is always null for reads. For writes, the
snapshot context always comes from the rbd header, but it is
acquired under protection of header semaphore and could change
thereafter, so we can't simply use what's available inside
rbd_do_op().
Eliminate the snapid parameter from rbd_do_op(), and set it
based on the I/O direction inside that function instead. Always
pass the snapshot context acquired in the caller, but reset it
to a null pointer inside rbd_do_op() if the operation is a read.
As a result, there is no difference in the read and write calls
to rbd_do_op() made in rbd_rq_fn(), so just call it unconditionally.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The only callers of rbd_do_op() are in rbd_rq_fn(), where call one
is used for writes and the other used for reads. The request passed
to rbd_do_op() already encodes the I/O direction, and that
information can be used inside the function to set the opcode and
flags value (rather than passing them in as arguments).
So get rid of the opcode and flags arguments to rbd_do_op().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Both rbd_req_read() and rbd_req_write() are simple wrapper routines
for rbd_do_op(), and each is only called once. Replace each wrapper
call with a direct call to rbd_do_op(), and get rid of the wrapper
functions.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The name of the "read-only" mapping option was inadvertently changed
in this commit:
f84344f3 rbd: separate mapping info in rbd_dev
Revert that hunk to return it to what it should be.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When rbd_dev_probe() calls rbd_dev_image_id() it expects to get
a 0 return code if successful, but it is getting a positive value.
The reason is that rbd_dev_image_id() returns the value it gets from
rbd_req_sync_exec(), which returns the number of bytes read in as a
result of the request. (This ultimately comes from
ceph_copy_from_page_vector() in rbd_req_sync_op()).
Force the return value to 0 when successful in rbd_dev_image_id().
Do the same in rbd_dev_v2_object_prefix().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
In rbd_dev_id_put(), there's a loop that's intended to determine
the maximum device id in use. But it isn't doing that at all,
the effect of how it's written is to simply use the just-put id
number, which ignores whole purpose of this function.
Fix the bug.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Now that v2 images support is fully implemented, have
rbd_dev_v2_probe() return 0 to indicate a successful probe.
(Note that an image that implements layering will fail
the probe early because of the feature chekc.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Version 2 images have two sets of feature bit fields. The first
indicates features possibly used by the image. The second indicates
features that the client *must* support in order to use the image.
When an image (or snapshot) is first examined, we need to make sure
that the local implementation supports the image's required
features. If not, fail the probe for the image.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define a new function rbd_dev_v2_refresh() to update/refresh the
snapshot context for a format version 2 rbd image. This function
will update anything that is not fixed for the life of an rbd
image--at the moment this is mainly the snapshot context and (for
a base mapping) the size.
Update rbd_refresh_header() so it selects which function to use
based on the image format.
Rename __rbd_refresh_header() to be rbd_dev_v1_refresh()
to be consistent with the naming of its version 2 counterpart.
Similarly rename rbd_refresh_header() to be rbd_dev_refresh().
Unrelated--we use rbd_image_format_valid() here. Delete the other
use of it, which was primarily put in place to ensure that function
was referenced at the time it was defined.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Encapsulate the code that handles updating the size of a mapping
after an rbd image has been refreshed. This is done in anticipation
of the next patch, which will make this common code for format 1 and
2 images.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This shouldn't actually be possible because the layout struct is
constructed from the RBD header and validated then.
[elder@inktank.com: converted BUG() call to equivalent rbd_assert()]
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
There are three fields that are not yet updated for format 2 rbd
image headers: the version of the header object; the encryption
type; and the compression type. There is no interface defined for
fetching the latter two, so just initialize them explicitly to 0 for
now.
Change rbd_dev_v2_snap_context() so the caller can be supplied the
version for the header object.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define rbd_dev_v2_snap_name() to fetch the name for a particular
snapshot in a format 2 rbd image.
Define rbd_dev_v2_snap_info() to to be a wrapper for getting the
name, size, and features for a particular snapshot, using an
interface that matches the equivalent function for version 1 images.
Define rbd_dev_snap_info() wrapper function and use it to call the
appropriate function for getting the snapshot name, size, and
features, dependent on the rbd image format.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Fetch the snapshot context for an rbd format 2 image by calling
the "get_snapcontext" method on its header object.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The features values for an rbd format 2 image are fetched from the
server using a "get_features" method. The same method is used for
getting the features for a snapshot, so structure this addition with
a generic helper routine that can get this information for either.
The server will provide two 64-bit feature masks, one representing
the features potentially in use for this image (or its snapshot),
and one representing features that must be supported by the client
in order to work with the image.
For the time being, neither of these is really used so we keep
things simple and just record the first feature vector. Once we
start using these feature masks, what we record and what we expose
to the user will most likely change.
Signed-off-by: Alex Elder <elder@inktank.com>
The object prefix of an rbd format 2 image is fetched from the
server using a "get_object_prefix" method.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The size of an rbd format 2 image is fetched from the server using a
"get_size" method. The same method is used for getting the size of
a snapshot, so structure this addition with a generic helper routine
that we can get this information for either.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This defines a new function rbd_dev_probe() as a top-level
function for populating detailed information about an rbd device.
It first checks for the existence of a format 2 rbd image id object.
If it exists, the image is assumed to be a format 2 rbd image, and
another function rbd_dev_v2() is called to finish populating
header data for that image. If it does not exist, it is assumed to
be an old (format 1) rbd image, and calls a similar function
rbd_dev_v1() to populate its header information.
A new field, rbd_dev->format, is defined to record which version
of the rbd image format the device represents. For a valid mapped
rbd device it will have one of two values, 1 or 2.
So far, the format 2 images are not really supported; this is
laying out the infrastructure for fleshing out that support.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Create a function that encapsulates looking up the name, size and
features related to a given snapshot, which is indicated by its
index in an rbd device's snapshot context array of snapshot ids.
This interface will be used to hide differences between the format 1
and format 2 images.
At the moment this (looking up the name anyway) is slightly less
efficient than what's done currently, but we may be able to optimize
this a bit later on by cacheing the last lookup if it proves to be a
problem.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Record the features values for each rbd image and each of its
snapshots. This is really something that only becomes meaningful
for version 2 images, so this is just putting in place code
that will form common infrastructure.
It may be useful to expand the sysfs entries--and therefore the
information we maintain--for the image and for each snapshot.
But I'm going to hold off doing that until we start making
active use of the feature bits.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Pass the snapshot id and snapshot size rather than an index
to __rbd_add_snap_dev() to specify values for a new snapshot.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Josh proposed the following change, and I don't think I could
explain it any better than he did:
From: Josh Durgin <josh.durgin@inktank.com>
Date: Tue, 24 Jul 2012 14:22:11 -0700
To: ceph-devel <ceph-devel@vger.kernel.org>
Message-ID: <500F1203.9050605@inktank.com>
Right now the kernel still has one piece of rbd management
duplicated from the rbd command line tool: snapshot creation.
There's nothing special about snapshot creation that makes it
advantageous to do from the kernel, so I'd like to remove the
create_snap sysfs interface. That is,
/sys/bus/rbd/devices/<id>/create_snap
would be removed.
Does anyone rely on the sysfs interface for creating rbd
snapshots? If so, how hard would it be to replace with:
rbd snap create pool/image@snap
Is there any benefit to the sysfs interface that I'm missing?
Josh
This patch implements this proposal, removing the code that
implements the "snap_create" sysfs interface for rbd images.
As a result, quite a lot of other supporting code goes away.
Suggested-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
New format 2 rbd images are permanently identified by a unique image
id. Each rbd image also has a name, but the name can be changed.
A format 2 rbd image will have an object--whose name is based on the
image name--which maps an image's name to its image id.
Create a new function rbd_dev_image_id() that checks for the
existence of the image id object, and if it's found, records the
image id in the rbd_device structure.
Create a new rbd device attribute (/sys/bus/rbd/<num>/image_id) that
makes this information available.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An OSD object method call can be made using rbd_req_sync_exec().
Until now this has only been used for creating a new RBD snapshot,
and that has only required sending data out, not receiving anything
back from the OSD.
We will now need to get data back from an OSD on a method call, so
add parameters to rbd_req_sync_exec() that allow a buffer into which
returned data should be placed to be specified, along with its size.
Previously, rbd_req_sync_exec() passed a null pointer and zero
size to rbd_req_sync_op(); change this so the new inbound buffer
information is provided instead.
Rename the "buf" and "len" parameters in rbd_req_sync_op() to
make it more obvious they are describing inbound data.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In order to allow both read requests and write requests to be
initiated using rbd_req_sync_exec(), add an OSD flags value
which can be passed down to rbd_req_sync_op(). Rename the "data"
and "len" parameters to be more clear that they represent data
that is outbound.
At this point, this function is still only used (and only works) for
write requests.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
We're ready to handle header object (refresh) events at the point we
call rbd_bus_add_dev(). Set up the watch request on the rbd image
header just after that, and after we've registered the devices for
the snapshots for the initial snapshot context. Do this before
announce the disk as available for use.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the setting of the initial capacity for an rbd image mapping
into rb_init_disk().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
By the time rbd_dev_snaps_register() gets called during rbd device
initialization, the main device will have already been registered.
Similarly, a header refresh will only occur for an rbd device whose
Linux device is registered. There is therefore no need to verify
the main device is registered when registering a snapshot device.
For the time being, turn the check into a WARN_ON(), but it can
eventually just go away.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Call rbd_init_disk() from rbd_add() as soon as we have the major
device number for the mapping.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Hold off setting the device id and formatting the device name
in rbd_add() until just before it's needed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Read the rbd header information and call rbd_dev_set_mapping()
earlier--before registering the block device or setting up the sysfs
entries for the image. The sysfs entries provide users access to
some information that's only available after doing the rbd header
initialization, so this will make sure it's valid right away.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_header_set_snap() is a simple initialization routine for an rbd
device's mapping. It has to be called after the snapshot context
for the rbd_dev has been updated, but can be done before snapshot
devices have been registered.
Change the name to rbd_dev_set_mapping() to better reflect its
purpose, and call it a little sooner, before registering snapshot
devices.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When a new snapshot is found in an rbd device's updated snapshot
context, __rbd_add_snap_dev() is called to create and insert an
entry in the rbd devices list of snapshots. In addition, a Linux
device is registered to represent the snapshot.
For version 2 rbd images, it will be undesirable to initialize the
device right away. So in anticipation of that, this patch separates
the insertion of a snapshot entry in the snaps list from the
creation of devices for those snapshots.
To do this, create a new function rbd_dev_snaps_register() which
traverses the list of snapshots and calls rbd_register_snap_dev()
on any that have not yet been registered.
Rename rbd_dev_snap_devs_update() to be rbd_dev_snaps_update()
to better reflect that only the entry in the snaps list and not
the snapshot's device is affected by the function.
For now, call rbd_dev_snaps_register() immediately after each
call to rbd_dev_snaps_update().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the assignment of the header name for an rbd image a bit later,
outside rbd_add_parse_args() and into its caller.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An rbd_dev structure maintains a list of current snapshots that have
already been fully initialized. The entries on the list have type
struct rbd_snap, and each entry contains a copy of information
that's found in the rbd_dev's snapshot context and header.
The only caller of snap_by_name() is rbd_header_set_snap(). In that
call site any positive return value (the index in the snapshot
array) is ignored, so there's no need to return the index in
the snapshot context's id array when it's found.
rbd_header_set_snap() also has only one caller--rbd_add()--and that
call is made after a call to rbd_dev_snap_devs_update(). Because
the rbd_snap structures are initialized in that function, the
current snapshot list can be used instead of the snapshot context to
look up a snapshot's information by name.
Change snap_by_name() so it uses the snapshot list rather than the
rbd_dev's snapshot context in looking up snapshot information.
Return 0 if it's found rather than the snapshot id.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When rbd_bus_add_dev() is called (one spot--in rbd_add()), the rbd
image header has not even been read yet. This means that the list
of snapshots will be empty at the time of the call. As a result,
there is no need for the code that calls rbd_register_snap_dev()
for each entry in that list--so get rid of it.
Once the header has been read (just after returning), a call will
be made to rbd_dev_snap_devs_update(), which will then find every
snapshot in the context to be new and will therefore call
rbd_register_snap_dev() via __rbd_add_snap_dev() accomplishing
the same thing.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the calls to get the header semaphore out of
rbd_header_set_snap() and into its caller.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This just simplifies a few things in rbd_init_disk(), now that the
previous patch has moved a bunch of initialization code out if it.
Done separately to facilitate review.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move some of the code that initializes an rbd header out of
rbd_init_disk() and into its caller.
Move the code at the end of rbd_init_disk() that sets the device
capacity and activates the Linux device out of that function and
into the caller, ensuring we still have the disk size available
where we need it.
Update rbd_free_disk() so it still aligns well as an inverse of
rbd_init_disk(), moving the rbd_header_free() call out to its
caller.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is only one caller of snap_by_name(), and it passes two values
to be assigned, both of which are found within an rbd device
structure.
Change the interface so it just passes the address of the rbd_dev,
and make the assignments to its fields directly.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
With the exception of the snapshot name, all of the mapping-specific
fields in an rbd device structure are set in rbd_header_set_snap().
Pass the snapshot name to be assigned into rbd_header_set_snap()
to keep all of the mapping assignments together.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This is the first of two patches aimed at isolating the code that
sets the mapping information into a single spot.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This should have been done as part of this commit:
commit de71a2970d
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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
The "notify_timeout" rbd device option is never used, so get rid of
it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda 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/3063
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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/1761
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Dan 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Create a simple helper that handles the common case of calling
__rbd_refresh_header() while holding the ctl_mutex.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add a new parameter to __rbd_refresh_header() through which the
version of the header object is passed back to the caller. In most
cases this isn't needed. The main motivation is to normalize
(almost) all calls to __rbd_refresh_header() so they are all
wrapped immediately by mutex_lock()/mutex_unlock().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This fixes a few issues in rbd_header_from_disk():
- There is a check intended to catch overflow, but it's wrong in
two ways.
- First, the type we don't want to overflow is size_t, not
unsigned int, and there is now a SIZE_MAX we can use for
use with that type.
- Second, we're allocating the snapshot ids and snapshot
image sizes separately (each has type u64; on disk they
grouped together as a rbd_image_header_ondisk structure).
So we can use the size of u64 in this overflow check.
- If there are no snapshots, then there should be no snapshot
names. Enforce this, and issue a warning if we encounter a
header with no snapshots but a non-zero snap_names_len.
- When saving the snapshot names into the header, be more direct
in defining the offset in the on-disk structure from which
they're being copied by using "snap_count" rather than "i"
in the array index.
- If an error occurs, the "snapc" and "snap_names" fields are
freed at the end of the function. Make those fields be null
pointers after they're freed, to be explicit that they are
no longer valid.
- Finally, move the definition of the local variable "i" to the
innermost scope in which it's needed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
All of the callers of rbd_req_sync_op() except one pass a non-null
"ops" pointer. The only one that does not is rbd_req_sync_read(),
which passes CEPH_OSD_OP_READ as its "opcode" and, CEPH_OSD_FLAG_READ
for "flags".
By allocating the ops array in rbd_req_sync_read() and moving the
special case code for the null ops pointer into it, it becomes
clear that much of that code is not even necessary.
In addition, the "opcode" argument to rbd_req_sync_op() is never
actually used, so get rid of that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_header_add_snap() passes the address of a version variable to
rbd_req_sync_exec(), but it ignores the result. Just pass a null
pointer instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Either rbd_create_rw_ops() will succeed, or it will fail because a
memory allocation failed. Have it just return a valid pointer or
null rather than stuffing a pointer into a provided address and
returning an errno.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
It's not obvious whether the snapshot pointer whose address is
provided to __rbd_add_snap_dev() will be assigned by that function.
Change it to return the snapshot, or a pointer-coded errno in the
event of a failure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_unwatch() only ever uses rbd_dev->header_name as the
value of its "object_name" parameter, and that value is available
within the function already. So get rid of the parameter.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_notify_ack() only ever uses rbd_dev->header_name as the
value of its "object_name" parameter, and that value is available
within the function already. So get rid of the parameter.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_notify() only ever uses rbd_dev->header_name as the
value of its "object_name" parameter, and that value is available
within the function already. So get rid of the parameter.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_watch() is only called in one place, and in that place
it passes rbd_dev->header_name as the value of the "object_name"
parameter. This value is available within the function already.
Having the extra parameter leaves the impression the object name
could take on different values, but it does not.
So get rid of the parameter. We can always add it back again if
we find we want to watch some other object in the future.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Both rbd_register_snap_dev() and __rbd_remove_snap_dev() have
rbd_dev parameters that are unused. Remove them.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The function rbd_header_from_disk() is only called in one spot, and
it passes GFP_KERNEL as its value for the gfp_flags parameter.
Just drop that parameter and substitute GFP_KERNEL everywhere within
that function it had been used. (If we find we need the parameter
again in the future it's easy enough to add back again.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The "snapc" parameter to in rbd_req_sync_read() is not used, so
get rid of it.
Reported-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The "id" field of an rbd device structure represents the unique
client-local device id mapped to the underlying rbd image. Each rbd
image will have another id--the image id--and each snapshot has its
own id as well. The simple name "id" no longer conveys the
information one might like to have.
Rename the device "id" field in struct rbd_dev to be "dev_id" to
make it a little more obvious what we're dealing with without having
to think more about context.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
If an rbd image header is read and it doesn't begin with the
expected magic information, a warning is displayed. This is
a fairly simple test, but it could be extended at some point.
Fix the comparison so it actually looks at the "text" field
rather than the front of the structure.
In any case, encapsulate the validity test in its own function.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There was a dout() call in rbd_do_request() that was reporting
the reporting the offset as the length and vice versa. While
fixing that I did a quick scan of other dout() calls and fixed
a couple of other minor things.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This just replaces a while loop with list_for_each_entry_safe()
in __rbd_remove_all_snaps().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In commit c666601a there was inadvertently added an extra
initialization of rbd_dev->header_rwsem. This gets rid of the
duplicate.
Reported-by: Guangliang Zhao <gzhao@suse.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The snap_seq field in an rbd_image_header structure held the value
from the rbd image header when it was last refreshed. We now
maintain this value in the snapc->seq field. So get rid of the
other one.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_header_add_snap() there is code to set snapc->seq to the
just-added snapshot id. This is the only remnant left of the
use of that field for recording which snapshot an rbd_dev was
associated with. That functionality is no longer supported,
so get rid of that final bit of code.
Doing so means we never actually set snapc->seq any more. On the
server, the snapshot context's sequence value represents the highest
snapshot id ever issued for a particular rbd image. So we'll make
it have that meaning here as well. To do so, set this value
whenever the rbd header is (re-)read. That way it will always be
consistent with the rest of the snapshot context we maintain.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_header_set_snap(), there is logic to make the snap context's
seq field get set to a particular snapshot id, or 0 if there is no
snapshot for the rbd image.
This seems to be an artifact of how the current snapshot id for an
rbd_dev was recorded before the rbd_dev->snap_id field began to be
used for that purpose.
There's no need to update the value of snapc->seq here any more, so
stop doing it. Tidy up a few local variables in that function
while we're at it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In what appears to be an artifact of a different way of encoding
whether an rbd image maps a snapshot, __rbd_refresh_header() has
code that arranges to update the seq value in an rbd image's
snapshot context to point to the first entry in its snapshot
array if that's where it was pointing initially.
We now use rbd_dev->snap_id to record the snapshot id--using the
special value CEPH_NOSNAP to indicate the rbd_dev is not mapping a
snapshot at all.
There is therefore no need to check for this case, nor to update the
seq value, in __rbd_refresh_header(). Just preserve the seq value
that rbd_read_header() provides (which, at the moment, is nothing).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Previously the original header version was sent. Now, we update it
when the header changes.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This prevents a race between requests with a given snap context and
header updates that free it. The osd client was already expecting the
snap context to be reference counted, since it get()s it in
ceph_osdc_build_request and put()s it when the request completes.
Also remove the second down_read()/up_read() on header_rwsem in
rbd_do_request, which wasn't actually preventing this race or
protecting any other data.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
If an image was mapped to a snapshot, the size of the head version
would be shown. Protect capacity with header_rwsem, since it may
change.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Snapshots cannot be resized, and the new capacity of head should not
be reflected by the snapshot.
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
When a snapshot is deleted, the OSD will return ENOENT when reading
from it. This is normally interpreted as a hole by rbd, which will
return zeroes. To minimize the time in which this can happen, stop
requests early when we are notified that our snapshot no longer
exists.
[elder@inktank.com: updated __rbd_init_snaps_header() logic]
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Several functions include a num_reply parameter, but it is never
used. Just get rid of it everywhere--it seems to be something
that never got fully implemented.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Use the name "ceph_opts" consistently (rather than just "opt") for
pointers to a ceph_options structure.
Change the few spots that don't use "rbd_opts" for a rbd_options
pointer to match the rest.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Rename variables named "obj" which represent object names so they're
consistently named "object_name".
Rename the "cls" and "method" parameters in rbd_req_sync_exec()
to be "class_name" and "method_name", and make similar changes
to the names of local variables in that function representing
the lengths of those names.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An rbd image is not a single object, but a logical construct made up
of an aggregation of objects.
Rename some fields in struct rbd_dev, in hopes of reinforcing this.
obj --> image_name
obj_len --> image_name_len
obj_md_name --> header_name
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Most variables that represent a struct rbd_device are named
"rbd_dev", but in some cases "dev" is used instead. Change all the
"dev" references so they use "rbd_dev" consistently, to make it
clear from the name that we're working with an RBD device (as
opposed to, for example, a struct device). Similarly, change the
name of the "dev" field in struct rbd_notify_info to be "rbd_dev".
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the snapshot
name recorded for an rbd image in a struct rbd_dev. Remove the
limitation by allocating space for the snapshot name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the rbd image
name recorded in a struct rbd_dev. Remove the limitation by
allocating space for the image name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the header
name recorded for an rbd image in a struct rbd_dev. Remove the
limitation by allocating space for the header name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the object
prefix recorded for an rbd image in a struct rbd_image_header.
Remove the limitation by allocating space for the object prefix
dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the pool name
recorded for an rbd image in a struct rbd_device. Remove the
limitation by allocating space for the pool name ynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add an entry under /sys/bus/rbd/devices/<N>/ named "pool_id" that
provides the id for the pool the rbd image is assocatied with. This
is in addition to the pool name already provided.
Rename the "poolid" field in struct rbd_device to be "pool_id".
Update the documentation to reflect the addition of this new entry.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Each rbd image has a name that forms the basis of all data objects
backing the device. Old (format 1) images refer to this name as the
"block name," while new (format 2) images use the term "object
prefix" for this.
Change the field name in the in-core rbd image header structure to
reflect the more modern usage. We intentionally keep the the name
"block_name" in the on-disk definition for format 1 image headers.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define a new function dup_token(), to be used during argument
parsing for making dynamically-allocated copies of tokens being
parsed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_req_sync_notify_ack(), a local variable was needlessly being
used to hold a null pointer. Just pass NULL instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Sparse complains about this because:
drivers/block/rbd.c:996:20: warning: cast to restricted __le32
drivers/block/rbd.c:996:20: warning: cast from restricted __le16
These are set in osd_req_encode_op() and they are le16.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This function rereads the entire header and handles any changes in
it, not just changes in snapshots.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Snapshot sizes should be the same type as regular image sizes. This
only affects their displayed size in sysfs, not the reported size of
an actual block device sizes.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
The snapid parameters passed to rbd_do_op() and rbd_req_sync_op()
are now always either a valid snapid or an explicit CEPH_NOSNAP.
[elder@dreamhost.com: Rephrased the description]
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
When a device was open at a snapshot, and snapshots were deleted or
added, data from the wrong snapshot could be read. Instead of
assuming the snap context is constant, store the actual snap id when
the device is initialized, and rely on the OSDs to signal an error
if we try reading from a snapshot that was deleted.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
This is updated whenever a snapshot is added or deleted, and the
snapc pointer is changed with every refresh of the header.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
ondisk->snap_count is read from disk via rbd_req_sync_read() and thus
needs validation. Otherwise, a bogus `snap_count' could overflow the
kmalloc() size, leading to memory corruption.
Also use `u32' consistently for `snap_count'.
[elder@dreamhost.com: changed to use UINT_MAX rather than ULONG_MAX]
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
We should use the gfp_flags that the caller specified instead of
GFP_KERNEL here.
There is only one caller and it uses GFP_KERNEL, so this change is
just a cleanup and doesn't change how the code works.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
This was an ill-conceived feature that has been removed from Ceph. Do
this gracefully:
- reject attempts to specify a preferred_osd via the ioctl
- stop exposing this information via virtual xattrs
- always fill in -1 for requests, in case we talk to an older server
- don't calculate preferred_osd placements/pgids
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>
A recent change made changes to the rbd_client_list be protected by
a spinlock. Unfortunately in rbd_put_client(), the lock is taken
before possibly dropping the last reference to an rbd_client, and on
the last reference that eventually calls flush_workqueue() which can
sleep.
The problem was flagged by a debug spinlock warning:
BUG: spinlock wrong CPU on CPU#3, rbd/27814
The solution is to move the spinlock acquisition and release inside
rbd_client_release(), which is the spot where it's really needed for
protecting the removal of the rbd_client from the client list.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
A new temporary header is allocated each time the header changes, but
only the changed properties are copied over. We don't need a new
semaphore for each header update.
This addresses http://tracker.newdream.net/issues/2174
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Currently an rbd device's id is released when it is removed, but it
is done before the code is run to clean up sysfs-related files (such
as /sys/bus/rbd/devices/1).
It's possible that an rbd is still in use after the rbd_remove()
call has been made. It's essentially the same as an active inode
that stays around after it has been removed--until its final close
operation. This means that the id shows up as free for reuse at a
time it should not be.
The effect of this was seen by Jens Rehpoehler, who:
- had a filesystem mounted on an rbd device
- unmapped that filesystem (without unmounting)
- found that the mount still worked properly
- but hit a panic when he attempted to re-map a new rbd device
This re-map attempt found the previously-unmapped id available.
The subsequent attempt to reuse it was met with a panic while
attempting to (re-)install the sysfs entry for the new mapped
device.
Fix this by holding off "putting" the rbd id, until the rbd_device
release function is called--when the last reference is finally
dropped.
Note: This fixes: http://tracker.newdream.net/issues/1907
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Here is another set of small code tidy-ups:
- Define SECTOR_SHIFT and SECTOR_SIZE, and use these symbolic
names throughout. Tell the blk_queue system our physical
block size, in the (unlikely) event we want to use something
other than the default.
- Delete the definition of struct rbd_info, which is never used.
- Move the definition of dev_to_rbd() down in its source file,
just above where it gets first used, and change its name to
dev_to_rbd_dev().
- Replace an open-coded operation in rbd_dev_release() to use
dev_to_rbd_dev() instead.
- Calculate the segment size for a given rbd_device just once in
rbd_init_disk().
- Use the '%zd' conversion specifier in rbd_snap_size_show(),
since the value formatted is a size_t.
- Switch to the '%llu' conversion specifier in rbd_snap_id_show().
since the value formatted is unsigned.
Signed-off-by: Alex Elder <elder@dreamhost.com>
A few blocks of code are rearranged a bit here:
- In rbd_header_from_disk():
- Don't bother computing snap_count until we're sure the
on-disk header starts with a good signature.
- Move a few independent lines of code so they are *after* a
check for a failed memory allocation.
- Get rid of unnecessary local variable "ret".
- Make a few other changes in rbd_read_header(), similar to the
above--just moving things around a bit while preserving the
functionality.
- In rbd_rq_fn(), just assign rq in the while loop's controlling
expression rather than duplicating it before and at the end of
the loop body. This allows the use of "continue" rather than
"goto next" in a number of spots.
- Rearrange the logic in snap_by_name(). End result is the same.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Once rbd_bus_type is registered, it allows an "add" operation via
the /sys/bus/rbd/add bus attribute, and adding a new rbd device that
way establishes a connection between the device and rbd_root_dev.
But rbd_root_dev is not registered until after the rbd_bus_type
registration is complete. This could (in principle anyway) result
in an invalid state.
Since rbd_root_dev has no tie to rbd_bus_type we can reorder these
two initializations and never be faced with this scenario.
In addition, unregister the device in the event the bus registration
fails at module init time.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The mon_addrs buffer in rbd_add is used to hold a copy of the
monitor IP addresses supplied via /sys/bus/rbd/add. That is
passed to rbd_get_client(), which never modifies it (nor do
any of the functions it gets passed to thereafter)--the mon_addr
parameter to rbd_get_client() is a pointer to constant data, so it
can't be modifed. Furthermore, rbd_get_client() has the length of
the mon_addrs buffer and that is used to ensure nothing goes beyond
its end.
Based on all this, there is no reason that a buffer needs to
be used to hold a copy of the mon_addrs provided via
/sys/bus/rbd/add. Instead, the location within that passed-in
buffer can be provided, along with the length of the "token"
therein which represents the monitor IP's.
A small change to rbd_add_parse_args() allows the address within the
buffer to be passed back, and the length is already returned. This
now means that, at least from the perspective of this interface,
there is no such thing as a list of monitor addresses that is too
long.
Signed-off-by: Alex Elder <elder@dreamhost.com>
The argument parsing routine already computes the size of the
mon_addrs buffer it extracts from the "command." Pass it to the
caller so it can use it to provide the length to rbd_get_client().
Signed-off-by: Alex Elder <elder@dreamhost.com>
This is a bit gratuitous, but there are a few things that can be
verified at build time rather than run time, so do that.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Make use of a few simple helper routines to parse the arguments
rather than sscanf(). This will treat both missing and too-long
arguments as invalid input (rather than silently truncating the
input in the too-long case). In time this can also be used by
rbd_add() to use the passed-in buffer in place, rather than copying
its contents into new buffers.
It appears to me that the sscanf() previously used would not
correctly handle a supplied snapshot--the two final "%s" conversion
specifications were not separated by a space, and I'm not sure
how sscanf() handles that situation. It may not be well-defined.
So that may be a bug this change fixes (but I didn't verify that).
The sizes of the mon_addrs and options buffers are now passed to
rbd_add_parse_args(), so they can be supplied to copy_token().
Signed-off-by: Alex Elder <elder@dreamhost.com>
Move the code that parses the arguments provided to rbd_add() (which
are supplied via /sys/bus/rbd/add) into a separate function.
Also rename the "mon_dev_name" variable in rbd_add() to be
"mon_addrs". The variable represents a list of one or more
comma-separated monitor IP addresses, each with an optional port
number. I think "mon_addrs" captures that notion a little better.
Signed-off-by: Alex Elder <elder@dreamhost.com>
If a couple pointers are initialized to NULL then a single
"out_nomem" label can be used for all of the memory allocation
failure cases in rbd_add().
Also, get rid of the "irc" local variable there. There is no
real need for "rc" to be type ssize_t, and it can be used in
the spot "irc" was.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The length of the string containing the monitor address
specification(s) will never exceed the length of the string passed
in to rbd_add(). The same holds true for the ceph + rbd options
string. So reduce the amount of memory allocated for these to
that length rather than the maximum (1024 bytes).
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Since rbd_get_client() currently returns an error code. It assigns
the rbd_client field of the rbd_device structure it is passed if
successful. Instead, have it return the created rbd_client
structure and return a pointer-coded error if there is an error.
This makes the assignment of the client pointer more obvious at the
call site.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Here are a few very simple cleanups:
- Add a "RBD_" prefix to the two driver name string definitions.
- Move the definition of struct rbd_request below struct rbd_req_coll
to avoid the need for an empty declaration of the latter.
- Move and group the definitions of rbd_root_dev_release() and
rbd_root_dev, as well as rbd_bus_type and rbd_bus_attrs[],
close to the top of the file. Arrange the latter so
rbd_bus_type.bus_attrs can be initialized statically.
- Get rid of an unnecessary local variable in rbd_open().
- Rework some hokey logic in rbd_bus_add_dev(), so the value of
"ret" at the end is either 0 or -ENOENT to avoid the need for
the code duplication that was there.
- Rename a goto target in rbd_add().
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The spinlock used to protect rbd_client_list is named "node_lock".
Rename it to "rbd_client_list_lock" to make it more obvious what
it's for.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Since rbd_client_create() is only called in one place, move the
acquisition of the mutex around that call inside that function.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Since rbd_get_client() is only called in one place, move the
acquisition of the mutex around that call inside that function.
Furthermore, within rbd_get_client(), it appears the mutex only
needs to be held while calling rbd_client_create(). (Moving
the lock inside that function will wait for the next patch.)
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
In rbd_get_client(), if a client is reused, a number of things
get done while still holding the list lock unnecessarily.
This just moves a few things that need no lock protection outside
the lock.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
It used to be that selecting a new unique identifier for an added
rbd device required searching all existing ones to find the highest
id is used. A recent change made that unnecessary, but made it
so that id's used were monotonically non-decreasing. It's a bit
more pleasant to have smaller rbd id's though, and this change
makes ids get allocated as they were before--each new id is one more
than the maximum currently in use.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The only time entries are added to or removed from the global
rbd_dev_list is exactly when a "put" or "get" operation is being
performed on a rbd_dev's id. So just move the list management code
into get/put routines.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The rbd_dev_list is just a simple list of all the current
rbd_devices. Using the ctl_mutex as a concurrency guard is
overkill. Instead, use a spinlock for that specific purpose.
This also reduces the window that the ctl_mutex needs to be held in
rbd_add().
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
In order to select a new unique identifier for an added rbd device,
the list of all existing ones is searched and a value one greater
than the highest id is used.
The list search can be avoided by using an atomic variable that
keeps track of the current highest id. Using a get/put model for
id's we can limit the boundless growth of id numbers a bit by
arranging to reuse the current highest id once it gets released.
Add these calls to "put" the id when an rbd is getting removed.
Note that this changes the pattern of device id's used--new values
will never be below the highest one seen so far (even if there
exists an unused lower one). I assert this is OK because the key
property of an rbd id is its uniqueness, not its magnitude.
Regardless, a follow-on patch will restore the old way of doing
things, I just think this commit just makes the incremental change
to atomics a little easier to understand.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Move the loop that finds a new unique rbd id to use into
its own helper function.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
There's already a constant for this anyway.
Since rbd_header_set_snap() is only used to set the rbd device
snap_name field, just do that within that function rather than
having it take the snap_name as an argument.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
v2: Changed interface rbd_header_set_snap() so it explicitly updates
the snap_name in the rbd_device. Also added a BUILD_BUG_ON()
to verify the size of the snap_name field is sufficient for
SNAP_HEAD_NAME.
The rbd_device structure maintains a duplicate copy of the
ceph_client pointer maintained in its rbd_client structure. There
appears to be no good reason for this, and its presence presents a
risk of them getting out of synch or otherwise misused. So kill it
off, and use the rbd_client copy only.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
ceph_parse_options() takes the address of a pointer as an argument
and uses it to return the address of an allocated structure if
successful. With this interface is not evident at call sites that
the pointer is always initialized. Change the interface to return
the address instead (or a pointer-coded error code) to make the
validity of the returned pointer obvious.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Some minor cleanups in "drivers/block/rbd.c:
- Use the more meaningful "RBD_MAX_OBJ_NAME_LEN" in place if "96"
in the definition of RBD_MAX_MD_NAME_LEN.
- Use DEFINE_SPINLOCK() to define and initialize node_lock.
- Drop a needless (char *) cast in parse_rbd_opts_token().
- Make a few minor formatting changes.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
rbd: fix safety of rbd_put_client()
rbd: fix a memory leak in rbd_get_client()
ceph: create a new session lock to avoid lock inversion
ceph: fix length validation in parse_reply_info()
ceph: initialize client debugfs outside of monc->mutex
ceph: change "ceph.layout" xattr to be "ceph.file.layout"
The rbd_client structure uses a kref to arrange for cleaning up and
freeing an instance when its last reference is dropped. The cleanup
routine is rbd_client_release(), and one of the things it does is
delete the rbd_client from rbd_client_list. It acquires node_lock
to do so, but the way it is done is still not safe.
The problem is that when attempting to reuse an existing rbd_client,
the structure found might already be in the process of getting
destroyed and cleaned up.
Here's the scenario, with "CLIENT" representing an existing
rbd_client that's involved in the race:
Thread on CPU A | Thread on CPU B
--------------- | ---------------
rbd_put_client(CLIENT) | rbd_get_client()
kref_put() | (acquires node_lock)
kref->refcount becomes 0 | __rbd_client_find() returns CLIENT
calls rbd_client_release() | kref_get(&CLIENT->kref);
| (releases node_lock)
(acquires node_lock) |
deletes CLIENT from list | ...and starts using CLIENT...
(releases node_lock) |
and frees CLIENT | <-- but CLIENT gets freed here
Fix this by having rbd_put_client() acquire node_lock. The result
could still be improved, but at least it avoids this problem.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
If an existing rbd client is found to be suitable for use in
rbd_get_client(), the rbd_options structure is not being
freed as it should. Fix that.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
