An osd request marked to linger will be re-submitted in the event
a connection to the target osd gets dropped.  Currently, if there
is a callback function associated with a request it will be called
each time a request is submitted--which for lingering requests can
be more than once.

Change it so a request--including lingering ones--will get completed
(from the perspective of the user of the osd client) exactly once.

This resolves:
    http://tracker.ceph.com/issues/3967Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The page alignment field for a request is currently set in
ceph_osdc_build_request().  It's not needed at that point
nor do either of its callers need that value assigned at
any point before they call ceph_osdc_start_request().

So move that assignment into ceph_osdc_start_request().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Use distinct fields for tracking the number of pages in a message's
page array and in a message's page list.  Currently only one or the
other is used at a time, but that will be changing soon.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The only remaining reason to pass the osd request to calc_layout()
is to fill in its r_num_pages and r_page_alignment fields.  Once it
fills those in, it doesn't do anything more with them.

We can therefore move those assignments into the caller, and get rid
of the "req" parameter entirely.

Note, however, that the only caller is ceph_osdc_new_request(),
and that immediately overwrites those fields with values based on
its passed-in page offset.  So the assignment inside calc_layout()
was redundant anyway.

This resolves:
    http://tracker.ceph.com/issues/4262Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Move the formatting of the object name (oid) to use for an object
request into the caller of calc_layout().  This makes the "vino"
parameter no longer necessary, so get rid of it.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Have calc_layout() pass the computed object number back to its
caller.  (This is a small step to simplify review.)
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

If an invalid layout is provided to ceph_osdc_new_request(), its
call to calc_layout() might return an error.  At that point in the
function we've already allocated an osd request structure, so we
need to free it (drop a reference) in the event such an error
occurs.

The only other value calc_layout() will return is 0, so make that
explicit in the successful case.

This resolves:
    http://tracker.ceph.com/issues/4240Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Use the new version of the encoding for osd requests and replies.  In the
process, update the way we are tracking request ops and reply lengths and
results in the struct ceph_osd_request.  Update the rbd and fs/ceph users
appropriately.

The main changes are:
 - we keep pointers into the request memory for fields we need to update
   each time the request is sent out over the wire
 - we keep information about the result in an array in the request struct
   where the users can easily get at it.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Instead of using the old ceph_object_layout struct, update our internal
ceph_calc_object_layout method to use the ceph_pg type.  This allows us to
pass the full 32-bit precision of the pgid.seed to the callers.  It also
allows some callers to avoid reaching into the request structures for the
struct ceph_object_layout fields.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Always decode data into our cpu-native ceph_pg type that has the correct
field widths.  Limit any remaining uses of ceph_pg_v1 to dealing with the
legacy protocol.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Rename the old version this type to distinguish it from the new version.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Add support for CEPH_OSD_OP_STAT operations in the osd client
and in rbd.

This operation sends no data to the osd; everything required is
encoded in identity of the target object.

The result will be ENOENT if the object doesn't exist.  If it does
exist and no other error occurs the server returns the size and last
modification time of the target object as output data (in little
endian format).  The size is a 64 bit unsigned and the time is
ceph_timespec structure (two unsigned 32-bit integers, representing
a seconds and nanoseconds value).

This resolves:
    http://tracker.ceph.com/issues/4007Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Simplify the way the data length recorded in a message header is
calculated in ceph_osdc_build_request().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

In osd_req_encode_op() there are a few cases that handle osd
opcodes that are never used in the kernel.  The presence of
this code gives the impression it's correct (which really can't
be assumed), and may impose some unnecessary restrictions on
some upcoming refactoring of this code.

So delete this effectively dead code, and report uses of the
previously handled cases as unsupported.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

If osd_req_encode_op() is given any opcode it doesn't recognize
it reports an error.

This patch fleshes out that routine to distinguish between
well-defined but unsupported values and values that are simply
bogus.

This and the next commit are related to:
    http://tracker.ceph.com/issues/4126Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There are no actual users of ceph_osdc_wait_event().  This would
have been one-shot events, but we no longer support those so just
get rid of this function.

Since this leaves nothing else that waits for the completion of an
event, we can get rid of the completion in a struct ceph_osd_event.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There is only one caller of ceph_osdc_create_event(), and it
provides 0 as its "one_shot" argument.  Get rid of that argument and
just use 0 in its place.

Replace the code in handle_watch_notify() that executes if one_shot
is nonzero in the event with a BUG_ON() call.

While modifying "osd_client.c", give handle_watch_notify() static
scope.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There is no caller of ceph_calc_raw_layout() outside of libceph, so
there's no need to export from the module.

Furthermore, there is only one caller, in calc_layout(), and it
is not much more than a simple wrapper for that function.

So get rid of ceph_calc_raw_layout() and embed it instead within
calc_layout().

While touching "osd_client.c", get rid of the unnecessary forward
declaration of __send_request().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The only callers of ceph_osdc_init() and ceph_osdc_stop()
ceph_create_client() and ceph_destroy_client() (respectively)
and they are in the same kernel module as those two functions.
There's therefore no need to export those interfaces, so don't.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Two of the three callers of the osd client's send_queued() function
already hold the osd client mutex and drop it before the call.

Change send_queued() so it assumes the caller holds the mutex, and
update all callers accordingly.  Rename it __send_queued() to match
the convention used elsewhere in the file with respect to the lock.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The "num_reply" parameter to ceph_osdc_new_request() is never
used inside that function, so get rid of it.

Note that ceph_sync_write() passes 2 for that argument, while all
other callers pass 1.  It doesn't matter, but perhaps someone should
verify this doesn't indicate a problem.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There is only one caller of ceph_osdc_writepages(), and it always
passes 0 as its "flags" argument.  Get rid of that argument and
replace its use in ceph_osdc_writepages() with 0.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There is only one caller of ceph_osdc_writepages(), and it always
passes 0 as its "dosync" argument.  Get rid of that argument and
replace its use in ceph_osdc_writepages() with 0.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There is only one caller of ceph_osdc_writepages(), and it always
passes the value true as its "nofail" argument.  Get rid of that
argument and replace its use in ceph_osdc_writepages() with the
constant value true.

This and a number of cleanup patches that follow resolve:
    http://tracker.ceph.com/issues/4126Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There is a check in the completion path for osd requests that
ensures the number of pages allocated is enough to hold the amount
of incoming data expected.

For bio requests coming from rbd the "number of pages" is not really
meaningful (although total length would be).  So stop requiring that
nr_pages be supplied for bio requests.  This is done by checking
whether the pages pointer is null before checking the value of
nr_pages.

Note that this value is passed on to the messenger, but there it's
only used for debugging--it's never used for validation.

While here, change another spot that used r_pages in a debug message
inappropriately, and also invalidate the r_con_filling_msg pointer
after dropping a reference to it.

This resolves:
    http://tracker.ceph.com/issues/3875Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Currently, if the OSD client finds an osd request has had a bio list
attached to it, it drops a reference to it (or rather, to the first
entry on that list) when the request is released.

The code that added that reference (i.e., the rbd client) is
therefore required to take an extra reference to that first bio
structure.

The osd client doesn't really do anything with the bio pointer other
than transfer it from the osd request structure to outgoing (for
writes) and ingoing (for reads) messages.  So it really isn't the
right place to be taking or dropping references.

Furthermore, the rbd client already holds references to all bio
structures it passes to the osd client, and holds them until the
request is completed.  So there's no need for this extra reference
whatsoever.

So remove the bio_put() call in ceph_osdc_release_request(), as
well as its matching bio_get() call in rbd_osd_req_create().

This change could lead to a crash if old libceph.ko was used with
new rbd.ko.  Add a compatibility check at rbd initialization time to
avoid this possibilty.

This resolves:
    http://tracker.ceph.com/issues/3798    and
    http://tracker.ceph.com/issues/3799Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

ceph_calc_file_object_mapping() takes (among other things) a "file"
offset and length, and based on the layout, determines the object
number ("bno") backing the affected portion of the file's data and
the offset into that object where the desired range begins.  It also
computes the size that should be used for the request--either the
amount requested or something less if that would exceed the end of
the object.

This patch changes the input length parameter in this function so it
is used only for input.  That is, the argument will be passed by
value rather than by address, so the value provided won't get
updated by the function.

The value would only get updated if the length would surpass the
current object, and in that case the value it got updated to would
be exactly that returned in *oxlen.

Only one of the two callers is affected by this change.  Update
ceph_calc_raw_layout() so it records any updated value.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Since every osd message is now prepared to include trailing data,
there's no need to check ahead of time whether any operations will
make use of the trail portion of the message.

We can drop the second argument to get_num_ops(), and as a result we
can also get rid of op_needs_trail() which is no longer used.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

An osd request structure contains an optional trail portion, which
if present will contain data to be passed in the payload portion of
the message containing the request.  The trail field is a
ceph_pagelist pointer, and if null it indicates there is no trail.

A ceph_pagelist structure contains a length field, and it can
legitimately hold value 0.  Make use of this to change the
interpretation of the "trail" of an osd request so that every osd
request has trailing data, it just might have length 0.

This means we change the r_trail field in a ceph_osd_request
structure from a pointer to a structure that is always initialized.

Note that in ceph_osdc_start_request(), the trail pointer (or now
address of that structure) is assigned to a ceph message's trail
field.  Here's why that's still OK (looking at net/ceph/messenger.c):
    - What would have resulted in a null pointer previously will now
      refer to a 0-length page list.  That message trail pointer
      is used in two functions, write_partial_msg_pages() and
      out_msg_pos_next().
    - In write_partial_msg_pages(), a null page list pointer is
      handled the same as a message with 0-length trail, and both
      result in a "in_trail" variable set to false.  The trail
      pointer is only used if in_trail is true.
    - The only other place the message trail pointer is used is
      out_msg_pos_next().  That function is only called by
      write_partial_msg_pages() and only touches the trail pointer
      if the in_trail value it is passed is true.
Therefore a null ceph_msg->trail pointer is equivalent to a non-null
pointer referring to a 0-length page list structure.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Reformat __reset_osd() into three distinct blocks of code
handling the three return cases.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Otherwise osd may truncate the object to larger size.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

When ceph_osdc_handle_map() is called to process a new osd map,
kick_requests() is called to ensure all affected requests are
updated if necessary to reflect changes in the osd map.  This
happens in two cases:  whenever an incremental map update is
processed; and when a full map update (or the last one if there is
more than one) gets processed.

In the former case, the kick_requests() call is followed immediately
by a call to reset_changed_osds() to ensure any connections to osds
affected by the map change are reset.  But for full map updates
this isn't done.

Both cases should be doing this osd reset.

Rather than duplicating the reset_changed_osds() call, move it into
the end of kick_requests().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

The kick_requests() function is called by ceph_osdc_handle_map()
when an osd map change has been indicated.  Its purpose is to
re-queue any request whose target osd is different from what it
was when it was originally sent.

It is structured as two loops, one for incomplete but registered
requests, and a second for handling completed linger requests.
As a special case, in the first loop if a request marked to linger
has not yet completed, it is moved from the request list to the
linger list.  This is as a quick and dirty way to have the second
loop handle sending the request along with all the other linger
requests.

Because of the way it's done now, however, this quick and dirty
solution can result in these incomplete linger requests never
getting re-sent as desired.  The problem lies in the fact that
the second loop only arranges for a linger request to be sent
if it appears its target osd has changed.  This is the proper
handling for *completed* linger requests (it avoids issuing
the same linger request twice to the same osd).

But although the linger requests added to the list in the first loop
may have been sent, they have not yet completed, so they need to be
re-sent regardless of whether their target osd has changed.

The first required fix is we need to avoid calling __map_request()
on any incomplete linger request.  Otherwise the subsequent
__map_request() call in the second loop will find the target osd
has not changed and will therefore not re-send the request.

Second, we need to be sure that a sent but incomplete linger request
gets re-sent.  If the target osd is the same with the new osd map as
it was when the request was originally sent, this won't happen.
This can be fixed through careful handling when we move these
requests from the request list to the linger list, by unregistering
the request *before* it is registered as a linger request.  This
works because a side-effect of unregistering the request is to make
the request's r_osd pointer be NULL, and *that* will ensure the
second loop actually re-sends the linger request.

Processing of such a request is done at that point, so continue with
the next one once it's been moved.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>