Commit Graph

483 Commits

Author SHA1 Message Date
Alex Elder 23c08a9cb2 libceph: define ceph_osd_data_length()
One more osd data helper, which returns the length of the
data item, regardless of its type.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:09 -07:00
Alex Elder c54d47bfad libceph: define a few more helpers
Define ceph_osd_data_init() and ceph_osd_data_release() to clean up
a little code.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:08 -07:00
Alex Elder 43bfe5de9f libceph: define osd data initialization helpers
Define and use functions that encapsulate the initializion of a
ceph_osd_data structure.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:06 -07:00
Alex Elder 9fc6e06471 libceph: compute incoming bytes once
This is a simple change, extracting the number of incoming data
bytes just once in handle_reply().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:05 -07:00
Alex Elder 98fa5dd883 libceph: provide data length when preparing message
In prepare_message_data(), the length used to initialize the cursor
is taken from the header of the message provided.  I'm working
toward not using the header data length field to determine length in
outbound messages, and this is a step in that direction.  For
inbound messages this will be set to be the actual number of bytes
that are arriving (which may be less than the total size of the data
buffer available).

This resolves:
    http://tracker.ceph.com/issues/4589

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:03 -07:00
Alex Elder e5975c7c8e ceph: build osd request message later for writepages
Hold off building the osd request message in ceph_writepages_start()
until just before it will be submitted to the osd client for
execution.

We'll still create the request and allocate the page pointer array
after we learn we have at least one page to write.  A local variable
will be used to keep track of the allocated array of pages.  Wait
until just before submitting the request for assigning that page
array pointer to the request message.

Create ands use a new function osd_req_op_extent_update() whose
purpose is to serve this one spot where the length value supplied
when an osd request's op was initially formatted might need to get
changed (reduced, never increased) before submitting the request.

Previously, ceph_writepages_start() assigned the message header's
data length because of this update.  That's no longer necessary,
because ceph_osdc_build_request() will recalculate the right
value to use based on the content of the ops in the request.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:02 -07:00
Alex Elder 02ee07d300 libceph: hold off building osd request
Defer building the osd request until just before submitting it in
all callers except ceph_writepages_start().  (That caller will be
handed in the next patch.)

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:01 -07:00
Alex Elder acead002b2 libceph: don't build request in ceph_osdc_new_request()
This patch moves the call to ceph_osdc_build_request() out of
ceph_osdc_new_request() and into its caller.

This is in order to defer formatting osd operation information into
the request message until just before request is started.

The only unusual (ab)user of ceph_osdc_build_request() is
ceph_writepages_start(), where the final length of write request may
change (downward) based on the current inode size or the oldest
snapshot context with dirty data for the inode.

The remaining callers don't change anything in the request after has
been built.

This means the ops array is now supplied by the caller.  It also
means there is no need to pass the mtime to ceph_osdc_new_request()
(it gets provided to ceph_osdc_build_request()).  And rather than
passing a do_sync flag, have the number of ops in the ops array
supplied imply adding a second STARTSYNC operation after the READ or
WRITE requested.

This and some of the patches that follow are related to having the
messenger (only) be responsible for filling the content of the
message header, as described here:
    http://tracker.ceph.com/issues/4589

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:58 -07:00
Alex Elder a193080481 libceph: record message data length
Keep track of the length of the data portion for a message in a
separate field in the ceph_msg structure.  This information has
been maintained in wire byte order in the message header, but
that's going to change soon.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:57 -07:00
Alex Elder ace6d3a96f libceph: drop ceph_osd_request->r_con_filling_msg
A field in an osd request keeps track of whether a connection is
currently filling the request's reply message.  This patch gets rid
of that field.

An osd request includes two messages--a request and a reply--and
they're both associated with the connection that existed to its
the target osd at the time the request was created.

An osd request can be dropped early, even when it's in flight.
And at that time both messages are released.  It's possible the
reply message has been supplied to its connection to receive
an incoming response message at the time the osd request gets
dropped.  So ceph_osdc_release_request() revokes that message
from the connection before releasing it so things get cleaned up
properly.

Previously this may have caused a problem, because the connection
that a message was associated with might have gone away before the
revoke request.  And to avoid any problems using that connection,
the osd client held a reference to it when it supplies its response
message.

However since this commit:
    38941f80 libceph: have messages point to their connection
all messages hold a reference to the connection they are associated
with whenever the connection is actively operating on the message
(i.e. while the message is queued to send or sending, and when it
data is being received into it).  And if a message has no connection
associated with it, ceph_msg_revoke_incoming() won't do anything
when asked to revoke it.

As a result, there is no need to keep an additional reference to the
connection associated with a message when we hand the message to the
messenger when it calls our alloc_msg() method to receive something.
If the connection *were* operating on it, it would have its own
reference, and if not, there's no work to be done when we need to
revoke it.

So get rid of the osd request's r_con_filling_msg field.

This resolves:
    http://tracker.ceph.com/issues/4647

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:54 -07:00
Alex Elder ef4859d647 libceph: define ceph_decode_pgid() only once
There are two basically identical definitions of __decode_pgid()
in libceph, one in "net/ceph/osdmap.c" and the other in
"net/ceph/osd_client.c".  Get rid of both, and instead define
a single inline version in "include/linux/ceph/osdmap.h".

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:52 -07:00
Alex Elder 8058fd4503 libceph: drop mutex on error in handle_reply()
The osd client mutex is acquired just before getting a reference to
a request in handle_reply().  However the error paths after that
don't drop the mutex before returning as they should.

Drop the mutex after dropping the request reference.  Also add a
bad_mutex label at that point and use it so the failed request
lookup case can be handled with the rest.

This resolves:
    http://tracker.ceph.com/issues/4615

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:51 -07:00
Alex Elder b0270324c5 libceph: use osd_req_op_extent_init()
Use osd_req_op_extent_init() in ceph_osdc_new_request() to
initialize the one or two ops built in that function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:49 -07:00
Alex Elder d18d1e2807 libceph: clean up ceph_osd_new_request()
All callers of ceph_osd_new_request() pass either CEPH_OSD_OP_READ
or CEPH_OSD_OP_WRITE as the opcode value.  The function assumes it
by filling in the extent fields in the ops array it builds.  So just
assert that is the case, and don't bother calling op_has_extent()
before filling in the first osd operation in the array.

Define some local variables to gather the information to fill into
the first op, and then fill in the op array all in one place.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:48 -07:00
Alex Elder a19dadfba9 libceph: don't update op in calc_layout()
The ceph_osdc_new_request() an array of osd operations is built up
and filled in partially within that function and partially in the
called function calc_layout().  Move the latter part back out to
ceph_osdc_new_request() so it's all done in one place.  This makes
it unnecessary to pass the op pointer to calc_layout(), so get rid
of that parameter.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:47 -07:00
Alex Elder 75d1c941e5 libceph: pass offset and length out of calc_layout()
The purpose of calc_layout() is to determine, given a file offset
and length and a layout describing the placement of file data across
objects, where in "object space" that data resides.

Specifically, it determines which object should hold the first part
of the specified range of file data, and the offset and length of
data within that object.  The length will not exceed the bounds
of the object, and the caller is informed of that maximum length.

Add two parameters to calc_layout() to allow the object-relative
offset and length to be passed back to the caller.

This is the first steps toward having ceph_osdc_new_request() build
its osd op structure using osd_req_op_extent_init().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:46 -07:00
Alex Elder 33803f3300 libceph: define source request op functions
The rbd code has a function that allocates and populates a
ceph_osd_req_op structure (the in-core version of an osd request
operation).  When reviewed, Josh suggested two things: that the
big varargs function might be better split into type-specific
functions; and that this functionality really belongs in the osd
client rather than rbd.

This patch implements both of Josh's suggestions.  It breaks
up the rbd function into separate functions and defines them
in the osd client module as exported interfaces.  Unlike the
rbd version, however, the functions don't allocate an osd_req_op
structure; they are provided the address of one and that is
initialized instead.

The rbd function has been eliminated and calls to it have been
replaced by calls to the new routines.  The rbd code now now use a
stack (struct) variable to hold the op rather than allocating and
freeing it each time.

For now only the capabilities used by rbd are implemented.
Implementing all the other osd op types, and making the rest of the
code use it will be done separately, in the next few patches.

Note that only the extent, cls, and watch portions of the
ceph_osd_req_op structure are currently used.  Delete the others
(xattr, pgls, and snap) from its definition so nobody thinks it's
actually implemented or needed.  We can add it back again later
if needed, when we know it's been tested.

This (and a few follow-on patches) resolves:
    http://tracker.ceph.com/issues/3861

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:45 -07:00
Alex Elder a8dd0a37bc libceph: define osd_req_opcode_valid()
Define a separate function to determine the validity of an opcode,
and use it inside osd_req_encode_op() in order to unclutter that
function.

Don't update the destination op at all--and return zero--if an
unsupported or unrecognized opcode is seen in osd_req_encode_op().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:44 -07:00
Alex Elder 0baa1bd9b6 libceph: be explicit in masking bottom 16 bits
In ceph_osdc_build_request() there is a call to cpu_to_le16() which
provides a 64-bit value as its argument.  Because of the implied
byte swapping going on it looked pretty suspect to me.

At the moment it turns out the behavior is well defined, but masking
off those bottom bits explicitly eliminates this distraction, and is
in fact more directly related to the purpose of the message header's
data_off field.

This resolves:
    http://tracker.ceph.com/issues/4125

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:41 -07:00
Alex Elder 56fc565916 libceph: account for alignment in pages cursor
When a cursor for a page array data message is initialized it needs
to determine the initial value for cursor->last_piece.  Currently it
just checks if length is less than a page, but that's not correct.
The data in the first page in the array will be offset by a page
offset based on the alignment recorded for the data.  (All pages
thereafter will be aligned at the base of the page, so there's
no need to account for this except for the first page.)

Because this was wrong, there was a case where the length of a piece
would be calculated as all of the residual bytes in the message and
that plus the page offset could exceed the length of a page.

So fix this case.  Make sure the sum won't wrap.

This resolves a third issue described in:
    http://tracker.ceph.com/issues/4598

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:40 -07:00
Alex Elder 5df521b1ee libceph: page offset must be less than page size
Currently ceph_msg_data_pages_advance() allows the page offset value
to be PAGE_SIZE, apparently assuming ceph_msg_data_pages_next() will
treat it as 0.  But that doesn't happen, and the result led to a
helpful assertion failure.

Change ceph_msg_data_pages_advance() to truncate the offset to 0
before returning if it reaches PAGE_SIZE.

Make a few other minor adjustments in this area (comments and a
better assertion) while modifying it.

This resolves a second issue described in:
    http://tracker.ceph.com/issues/4598

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:39 -07:00
Alex Elder 1190bf06a6 libceph: fix broken data length assertions
It's OK for the result of a read to come back with fewer bytes than
were requested.  So don't trigger a BUG() in that case when
initializing the data cursor.

This resolves the first problem described in:
    http://tracker.ceph.com/issues/4598

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:38 -07:00
Alex Elder 6644ed7b7e libceph: make message data be a pointer
Begin the transition from a single message data item to a list of
them by replacing the "data" structure in a message with a pointer
to a ceph_msg_data structure.

A null pointer will indicate the message has no data; replace the
use of ceph_msg_has_data() with a simple check for a null pointer.

Create functions ceph_msg_data_create() and ceph_msg_data_destroy()
to dynamically allocate and free a data item structure of a given type.

When a message has its data item "set," allocate one of these to
hold the data description, and free it when the last reference to
the message is dropped.

This partially resolves:
    http://tracker.ceph.com/issues/4429

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:37 -07:00
Alex Elder 8ea299bcbc libceph: use only ceph_msg_data_advance()
The *_msg_pos_next() functions do little more than call
ceph_msg_data_advance().  Replace those wrapper functions with
a simple call to ceph_msg_data_advance().

This cleanup is related to:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:36 -07:00
Alex Elder 143334ff44 libceph: don't add to crc unless data sent
In write_partial_message_data() we aggregate the crc for the data
portion of the message as each new piece of the data item is
encountered.  Because it was computed *before* sending the data, if
an attempt to send a new piece resulted in 0 bytes being sent, the
crc crc across that piece would erroneously get computed again and
added to the aggregate result.  This would occasionally happen in
the evnet of a connection failure.

The crc value isn't really needed until the complete value is known
after sending all data, so there's no need to compute it before
sending.

So don't calculate the crc for a piece until *after* we know at
least one byte of it has been sent.  That will avoid this problem.

This resolves:
    http://tracker.ceph.com/issues/4450

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:35 -07:00
Alex Elder f5db90bcf2 libceph: kill last of ceph_msg_pos
The only remaining field in the ceph_msg_pos structure is
did_page_crc.  In the new cursor model of things that flag (or
something like it) belongs in the cursor.

Define a new field "need_crc" in the cursor (which applies to all
types of data) and initialize it to true whenever a cursor is
initialized.

In write_partial_message_data(), the data CRC still will be computed
as before, but it will check the cursor->need_crc field to determine
whether it's needed.  Any time the cursor is advanced to a new piece
of a data item, need_crc will be set, and this will cause the crc
for that entire piece to be accumulated into the data crc.

In write_partial_message_data() the intermediate crc value is now
held in a local variable so it doesn't have to be byte-swapped so
many times.  In read_partial_msg_data() we do something similar
(but mainly for consistency there).

With that, the ceph_msg_pos structure can go away,  and it no longer
needs to be passed as an argument to prepare_message_data().

This cleanup is related to:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:34 -07:00
Alex Elder 859a35d552 libceph: kill most of ceph_msg_pos
All but one of the fields in the ceph_msg_pos structure are now
never used (only assigned), so get rid of them.  This allows
several small blocks of code to go away.

This is cleanup of old code related to:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:33 -07:00
Alex Elder 643c68a4a9 libceph: use cursor resid for loop condition
Use the "resid" field of a cursor rather than finding when the
message data position has moved up to meet the data length to
determine when all data has been sent or received in
write_partial_message_data() and read_partial_msg_data().

This is cleanup of old code related to:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:32 -07:00
Alex Elder 4c59b4a278 libceph: collapse all data items into one
It turns out that only one of the data item types is ever used at
any one time in a single message (currently).
    - A page array is used by the osd client (on behalf of the file
      system) and by rbd.  Only one osd op (and therefore at most
      one data item) is ever used at a time by rbd.  And the only
      time the file system sends two, the second op contains no
      data.
    - A bio is only used by the rbd client (and again, only one
      data item per message)
    - A page list is used by the file system and by rbd for outgoing
      data, but only one op (and one data item) at a time.

We can therefore collapse all three of our data item fields into a
single field "data", and depend on the messenger code to properly
handle it based on its type.

This allows us to eliminate quite a bit of duplicated code.

This is related to:
    http://tracker.ceph.com/issues/4429

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:30 -07:00
Alex Elder 686be20875 libceph: get rid of read helpers
Now that read_partial_message_pages() and read_partial_message_bio()
are literally identical functions we can factor them out.  They're
pretty simple as well, so just move their relevant content into
read_partial_msg_data().

This is and previous patches together resolve:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:29 -07:00
Alex Elder 61fcdc97c0 libceph: no outbound zero data
There is handling in write_partial_message_data() for the case where
only the length of--and no other information about--the data to be
sent has been specified.  It uses the zero page as the source of
data to send in this case.

This case doesn't occur.  All message senders set up a page array,
pagelist, or bio describing the data to be sent.  So eliminate the
block of code that handles this (but check and issue a warning for
now, just in case it happens for some reason).

This resolves:
    http://tracker.ceph.com/issues/4426

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:28 -07:00
Alex Elder 878efabd32 libceph: use cursor for inbound data pages
The cursor code for a page array selects the right page, page
offset, and length to use for a ceph_tcp_recvpage() call, so
we can use it to replace a block in read_partial_message_pages().

This partially resolves:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:27 -07:00
Alex Elder 6518be47f9 libceph: kill ceph message bio_iter, bio_seg
The bio_iter and bio_seg fields in a message are no longer used, we
use the cursor instead.  So get rid of them and the functions that
operate on them them.

This is related to:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:26 -07:00
Alex Elder 463207aa40 libceph: use cursor for bio reads
Replace the use of the information in con->in_msg_pos for incoming
bio data.  The old in_msg_pos and the new cursor mechanism do
basically the same thing, just slightly differently.

The main functional difference is that in_msg_pos keeps track of the
length of the complete bio list, and assumed it was fully consumed
when that many bytes had been transferred.  The cursor does not assume
a length, it simply consumes all bytes in the bio list.  Because the
only user of bio data is the rbd client, and because the length of a
bio list provided by rbd client always matches the number of bytes
in the list, both ways of tracking length are equivalent.

In addition, for in_msg_pos the initial bio vector is selected as
the initial value of the bio->bi_idx, while the cursor assumes this
is zero.  Again, the rbd client always passes 0 as the initial index
so the effect is the same.

Other than that, they basically match:
    in_msg_pos      cursor
    ----------      ------
    bio_iter        bio
    bio_seg         vec_index
    page_pos        page_offset

The in_msg_pos field is initialized by a call to init_bio_iter().
The bio cursor is initialized by ceph_msg_data_cursor_init().
Both now happen in the same spot, in prepare_message_data().

The in_msg_pos field is advanced by a call to in_msg_pos_next(),
which updates page_pos and calls iter_bio_next() to move to the next
bio vector, or to the next bio in the list.  The cursor is advanced
by ceph_msg_data_advance().  That isn't currently happening so
add a call to that in in_msg_pos_next().

Finally, the next piece of data to use for a read is determined
by a bunch of lines in read_partial_message_bio().  Those can be
replaced by an equivalent ceph_msg_data_bio_next() call.

This partially resolves:
    http://tracker.ceph.com/issues/4428

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:25 -07:00
Alex Elder 25aff7c559 libceph: record residual bytes for all message data types
All of the data types can use this, not just the page array.  Until
now, only the bio type doesn't have it available, and only the
initiator of the request (the rbd client) is able to supply the
length of the full request without re-scanning the bio list.  Change
the cursor init routines so the length is supplied based on the
message header "data_len" field, and use that length to intiialize
the "resid" field of the cursor.

In addition, change the way "last_piece" is defined so it is based
on the residual number of bytes in the original request.  This is
necessary (at least for bio messages) because it is possible for
a read request to succeed without consuming all of the space
available in the data buffer.

This resolves:
    http://tracker.ceph.com/issues/4427

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:24 -07:00
Alex Elder 28a89ddece libceph: drop pages parameter
The value passed for "pages" in read_partial_message_pages() is
always the pages pointer from the incoming message, which can be
derived inside that function.  So just get rid of the parameter.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:23 -07:00
Alex Elder 888334f966 libceph: initialize data fields on last msg put
When the last reference to a ceph message is dropped,
ceph_msg_last_put() is called to clean things up.

For "normal" messages (allocated via ceph_msg_new() rather than
being allocated from a memory pool) it's sufficient to just release
resources.  But for a mempool-allocated message we actually have to
re-initialize the data fields in the message back to initial state
so they're ready to go in the event the message gets reused.

Some of this was already done; this fleshes it out so it's done
more completely.

This resolves:
    http://tracker.ceph.com/issues/4540

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:22 -07:00
Alex Elder 7e2766a113 libceph: send queued requests when starting new one
An osd expects the transaction ids of arriving request messages from
a given client to a given osd to increase monotonically.  So the osd
client needs to send its requests in ascending tid order.

The transaction id for a request is set at the time it is
registered, in __register_request().  This is also where the request
gets placed at the end of the osd client's unsent messages list.

At the end of ceph_osdc_start_request(), the request message for a
newly-mapped osd request is supplied to the messenger to be sent
(via __send_request()).  If any other messages were present in the
osd client's unsent list at that point they would be sent *after*
this new request message.

Because those unsent messages have already been registered, their
tids would be lower than the newly-mapped request message, and
sending that message first can violate the tid ordering rule.

Rather than sending the new request only, send all queued requests
(including the new one) at that point in ceph_osdc_start_request().
This ensures the tid ordering property is preserved.

With this in place, all messages should now be sent in tid order
regardless of whether they're being sent for the first time or
re-sent as a result of a call to osd_reset().

This resolves:
    http://tracker.ceph.com/issues/4392

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:21 -07:00
Alex Elder ad885927de libceph: keep request lists in tid order
In __map_request(), when adding a request to an osd client's unsent
list, add it to the tail rather than the head.  That way the newest
entries (with the highest tid value) will be last.

Maintain an osd's request list in order of increasing tid also.

Finally--to be consistent--maintain an osd client's "notarget" list
in that order as well.

This partially resolves:
    http://tracker.ceph.com/issues/4392

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:19 -07:00
Alex Elder e02493c07c libceph: requeue only sent requests when kicking
The osd expects incoming requests for a given object from a given
client to arrive in order, with the tid for each request being
greater than the tid for requests that have already arrived.  This
patch fixes two places the osd client might not maintain that
ordering.

For the osd client, the connection fault method is osd_reset().
That function calls __reset_osd() to close and re-open the
connection, then calls __kick_osd_requests() to cause all
outstanding requests for the affected osd to be re-sent after
the connection has been re-established.

When an osd is reset, any in-flight messages will need to be
re-sent.  An osd client maintains distinct lists for unsent and
in-flight messages.  Meanwhile, an osd maintains a single list of
all its requests (both sent and un-sent).  (Each message is linked
into two lists--one for the osd client and one list for the osd.)

To process an osd "kick" operation, the request list for the *osd*
is traversed, and each request is moved off whichever osd *client*
list it was on (unsent or sent) and placed onto the osd client's
unsent list.  (It remains where it is on the osd's request list.)

When that is done, osd_reset() calls __send_queued() to cause each
of the osd client's unsent messages to be sent.

OK, with that background...

As the osd request list is traversed each request is prepended to
the osd client's unsent list in the order they're seen.  The effect
of this is to reverse the order of these requests as they are put
(back) onto the unsent list.

Instead, build up a list of only the requests for an osd that have
already been sent (by checking their r_sent flag values).  Once an
unsent request is found, stop examining requests and prepend the
requests that need re-sending to the osd client's unsent list.

Preserve the original order of requests in the process (previously
re-queued requests were reversed in this process).  Because they
have already been sent, they will have lower tids than any request
already present on the unsent list.

Just below that, traverse the linger list in forward order as
before, but add them to the *tail* of the list rather than the head.
These requests get re-registered, and in the process are give a new
(higher) tid, so the should go at the end.

This partially resolves:
    http://tracker.ceph.com/issues/4392

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:18 -07:00
Alex Elder 92451b4910 libceph: no more kick_requests() race
Since we no longer drop the request mutex between registering and
mapping an osd request in ceph_osdc_start_request(), there is no
chance of a race with kick_requests().

We can now therefore map and send the new request unconditionally
(but we'll issue a warning should it ever occur).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:17 -07:00
Alex Elder dc4b870c97 libceph: slightly defer registering osd request
One of the first things ceph_osdc_start_request() does is register
the request.  It then acquires the osd client's map semaphore and
request mutex and proceeds to map and send the request.

There is no reason the request has to be registered before acquiring
the map semaphore.  So hold off doing so until after the map
semaphore is held.

Since register_request() is nothing more than a wrapper around
__register_request(), call the latter function instead, after
acquiring the request mutex.

That leaves register_request() unused, so get rid of it.

This partially resolves:
    http://tracker.ceph.com/issues/4392

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
2013-05-01 21:17:16 -07:00
Sage Weil e9966076cd libceph: wrap auth methods in a mutex
The auth code is called from a variety of contexts, include the mon_client
(protected by the monc's mutex) and the messenger callbacks (currently
protected by nothing).  Avoid chaos by protecting all auth state with a
mutex.  Nothing is blocking, so this should be simple and lightweight.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:17:15 -07:00
Sage Weil 27859f9773 libceph: wrap auth ops in wrapper functions
Use wrapper functions that check whether the auth op exists so that callers
do not need a bunch of conditional checks.  Simplifies the external
interface.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:17:14 -07:00
Sage Weil 0bed9b5c52 libceph: add update_authorizer auth method
Currently the messenger calls out to a get_authorizer con op, which will
create a new authorizer if it doesn't yet have one.  In the meantime, when
we rotate our service keys, the authorizer doesn't get updated.  Eventually
it will be rejected by the server on a new connection attempt and get
invalidated, and we will then rebuild a new authorizer, but this is not
ideal.

Instead, if we do have an authorizer, call a new update_authorizer op that
will verify that the current authorizer is using the latest secret.  If it
is not, we will build a new one that does.  This avoids the transient
failure.

This fixes one of the sorry sequence of events for bug

	http://tracker.ceph.com/issues/4282

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:17:13 -07:00
Sage Weil 4b8e8b5d78 libceph: fix authorizer invalidation
We were invalidating the authorizer by removing the ticket handler
entirely.  This was effective in inducing us to request a new authorizer,
but in the meantime it mean that any authorizer we generated would get a
new and initialized handler with secret_id=0, which would always be
rejected by the server side with a confusing error message:

 auth: could not find secret_id=0
 cephx: verify_authorizer could not get service secret for service osd secret_id=0

Instead, simply clear the validity field.  This will still induce the auth
code to request a new secret, but will let us continue to use the old
ticket in the meantime.  The messenger code will probably continue to fail,
but the exponential backoff will kick in, and eventually the we will get a
new (hopefully more valid) ticket from the mon and be able to continue.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:17:12 -07:00
Sage Weil 20e55c4cc7 libceph: clear messenger auth_retry flag when we authenticate
We maintain a counter of failed auth attempts to allow us to retry once
before failing.  However, if the second attempt succeeds, the flag isn't
cleared, which makes us think auth failed again later when the connection
resets for other reasons (like a socket error).

This is one part of the sorry sequence of events in bug

	http://tracker.ceph.com/issues/4282

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:17:11 -07:00
Sage Weil 3a23083bda libceph: implement RECONNECT_SEQ feature
This is an old protocol extension that allows the client and server to
avoid resending old messages after a reconnect (following a socket error).
Instead, the exchange their sequence numbers during the handshake.  This
avoids sending a bunch of useless data over the socket.

It has been supported in the server code since v0.22 (Sep 2010).

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:17:09 -07:00
Alex Elder 8a166d0536 libceph: more cleanup of write_partial_msg_pages()
Basically all cases in write_partial_msg_pages() use the cursor, and
as a result we can simplify that function quite a bit.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:06 -07:00
Alex Elder 9d2a06c275 libceph: kill message trail
The wart that is the ceph message trail can now be removed, because
its only user was the osd client, and the previous patch made that
no longer the case.

The result allows write_partial_msg_pages() to be simplified
considerably.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:05 -07:00
Alex Elder 95e072eb38 libceph: kill osd request r_trail
The osd trail is a pagelist, used only for a CALL osd operation
to hold the class and method names, along with any input data for
the call.

It is only currently used by the rbd client, and when it's used it
is the only bit of outbound data in the osd request.  Since we
already support (non-trail) pagelist data in a message, we can
just save this outbound CALL data in the "normal" pagelist rather
than the trail, and get rid of the trail entirely.

The existing pagelist support depends on the pagelist being
dynamically allocated, and ownership of it is passed to the
messenger once it's been attached to a message.  (That is to say,
the messenger releases and frees the pagelist when it's done with
it).  That means we need to dynamically allocate the pagelist also.

Note that we simply assert that the allocation of a pagelist
structure succeeds.  Appending to a pagelist might require a dynamic
allocation, so we're already assuming we won't run into trouble
doing so (we're just ignore any failures--and that should be fixed
at some point).

This resolves:
    http://tracker.ceph.com/issues/4407

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:04 -07:00
Alex Elder 9a5e6d09dd libceph: have osd requests support pagelist data
Add support for recording a ceph pagelist as data associated with an
osd request.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:03 -07:00
Alex Elder 175face2ba libceph: let osd ops determine request data length
The length of outgoing data in an osd request is dependent on the
osd ops that are embedded in that request.  Each op is encoded into
a request message using osd_req_encode_op(), so that should be used
to determine the amount of outgoing data implied by the op as it
is encoded.

Have osd_req_encode_op() return the number of bytes of outgoing data
implied by the op being encoded, and accumulate and use that in
ceph_osdc_build_request().

As a result, ceph_osdc_build_request() no longer requires its "len"
parameter, so get rid of it.

Using the sum of the op lengths rather than the length provided is
a valid change because:
    - The only callers of osd ceph_osdc_build_request() are
      rbd and the osd client (in ceph_osdc_new_request() on
      behalf of the file system).
    - When rbd calls it, the length provided is only non-zero for
      write requests, and in that case the single op has the
      same length value as what was passed here.
    - When called from ceph_osdc_new_request(), (it's not all that
      easy to see, but) the length passed is also always the same
      as the extent length encoded in its (single) write op if
      present.

This resolves:
    http://tracker.ceph.com/issues/4406

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:02 -07:00
Alex Elder e766d7b55e libceph: implement pages array cursor
Implement and use cursor routines for page array message data items
for outbound message data.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:17:01 -07:00
Alex Elder 6aaa4511de libceph: implement bio message data item cursor
Implement and use cursor routines for bio message data items for
outbound message data.

(See the previous commit for reasoning in support of the changes
in out_msg_pos_next().)

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:59 -07:00
Alex Elder 7fe1e5e57b libceph: use data cursor for message pagelist
Switch to using the message cursor for the (non-trail) outgoing
pagelist data item in a message if present.

Notes on the logic changes in out_msg_pos_next():
    - only the mds client uses a ceph pagelist for message data;
    - if the mds client ever uses a pagelist, it never uses a page
      array (or anything else, for that matter) for data in the same
      message;
    - only the osd client uses the trail portion of a message data,
      and when it does, it never uses any other data fields for
      outgoing data in the same message; and finally
    - only the rbd client uses bio message data (never pagelist).

Therefore out_msg_pos_next() can assume:
    - if we're in the trail portion of a message, the message data
      pagelist, data, and bio can be ignored; and
    - if there is a page list, there will never be any a bio or page
      array data, and vice-versa.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:58 -07:00
Alex Elder dd236fcb65 libceph: prepare for other message data item types
This just inserts some infrastructure in preparation for handling
other types of ceph message data items.  No functional changes,
just trying to simplify review by separating out some noise.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:57 -07:00
Alex Elder fe38a2b67b libceph: start defining message data cursor
This patch lays out the foundation for using generic routines to
manage processing items of message data.

For simplicity, we'll start with just the trail portion of a
message, because it stands alone and is only present for outgoing
data.

First some basic concepts.  We'll use the term "data item" to
represent one of the ceph_msg_data structures associated with a
message.  There are currently four of those, with single-letter
field names p, l, b, and t.  A data item is further broken into
"pieces" which always lie in a single page.  A data item will
include a "cursor" that will track state as the memory defined by
the item is consumed by sending data from or receiving data into it.

We define three routines to manipulate a data item's cursor: the
"init" routine; the "next" routine; and the "advance" routine.  The
"init" routine initializes the cursor so it points at the beginning
of the first piece in the item.  The "next" routine returns the
page, page offset, and length (limited by both the page and item
size) of the next unconsumed piece in the item.  It also indicates
to the caller whether the piece being returned is the last one in
the data item.

The "advance" routine consumes the requested number of bytes in the
item (advancing the cursor).  This is used to record the number of
bytes from the current piece that were actually sent or received by
the network code.  It returns an indication of whether the result
means the current piece has been fully consumed.  This is used by
the message send code to determine whether it should calculate the
CRC for the next piece processed.

The trail of a message is implemented as a ceph pagelist.  The
routines defined for it will be usable for non-trail pagelist data
as well.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:56 -07:00
Alex Elder 437945094f libceph: abstract message data
Group the types of message data into an abstract structure with a
type indicator and a union containing fields appropriate to the
type of data it represents.  Use this to represent the pages,
pagelist, bio, and trail in a ceph message.

Verify message data is of type NONE in ceph_msg_data_set_*()
routines.  Since information about message data of type NONE really
should not be interpreted, get rid of the other assertions in those
functions.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:55 -07:00
Alex Elder f9e15777af libceph: be explicit about message data representation
A ceph message has a data payload portion.  The memory for that data
(either the source of data to send or the location to place data
that is received) is specified in several ways.  The ceph_msg
structure includes fields for all of those ways, but this
mispresents the fact that not all of them are used at a time.

Specifically, the data in a message can be in:
    - an array of pages
    - a list of pages
    - a list of Linux bios
    - a second list of pages (the "trail")
(The two page lists are currently only ever used for outgoing data.)

Impose more structure on the ceph message, making the grouping of
some of these fields explicit.  Shorten the name of the
"page_alignment" field.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:54 -07:00
Alex Elder 97fb1c7f66 libceph: define ceph_msg_has_*() data macros
Define and use macros ceph_msg_has_*() to determine whether to
operate on the pages, pagelist, bio, and trail fields of a message.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:53 -07:00
Alex Elder 35b6280899 libceph: define and use ceph_crc32c_page()
Factor out a common block of code that updates a CRC calculation
over a range of data in a page.

This and the preceding patches are related to:
    http://tracker.ceph.com/issues/4403

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:52 -07:00
Alex Elder afb3d90e20 libceph: define and use ceph_tcp_recvpage()
Define a new function ceph_tcp_recvpage() that behaves in a way
comparable to ceph_tcp_sendpage().

Rearrange the code in both read_partial_message_pages() and
read_partial_message_bio() so they have matching structure,
(similar to what's in write_partial_msg_pages()), and use
this new function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:51 -07:00
Alex Elder 34d2d2006c libceph: encapsulate reading message data
Pull the code that reads the data portion into a message into
a separate function read_partial_msg_data().

Rename write_partial_msg_pages() to be write_partial_message_data()
to match its read counterpart, and to reflect its more generic
purpose.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:50 -07:00
Alex Elder e387d525b0 libceph: small write_partial_msg_pages() refactor
Define local variables page_offset and length to represent the range
of bytes within a page that will be sent by ceph_tcp_sendpage() in
write_partial_msg_pages().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:48 -07:00
Alex Elder 78625051b5 libceph: consolidate message prep code
In prepare_write_message_data(), various fields are initialized in
preparation for writing message data out.  Meanwhile, in
read_partial_message(), there is essentially the same block of code,
operating on message variables associated with an incoming message.

Generalize prepare_write_message_data() so it works for both
incoming and outcoming messages, and use it in both spots.  The
did_page_crc is not used for input (so it's harmless to initialize
it).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:47 -07:00
Alex Elder bae6acd9c6 libceph: use local variables for message positions
There are several places where a message's out_msg_pos or in_msg_pos
field is used repeatedly within a function.  Use a local pointer
variable for this purpose to unclutter the code.

This and the upcoming cleanup patches are related to:
    http://tracker.ceph.com/issues/4403

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:46 -07:00
Alex Elder 98a0370898 libceph: don't clear bio_iter in prepare_write_message()
At one time it was necessary to clear a message's bio_iter field to
avoid a bad pointer dereference in write_partial_msg_pages().

That no longer seems to be the case.  Here's why.

The message's bio fields represent (in this case) outgoing data.
Between where the bio_iter is made NULL in prepare_write_message()
and the call in that function to prepare_message_data(), the
bio fields are never used.

In prepare_message_data(), init-bio_iter() is called, and the result
of that overwrites the value in the message's bio_iter field.

Because it gets overwritten anyway, there is no need to set it to
NULL.  So don't do it.

This resolves:
    http://tracker.ceph.com/issues/4402

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:45 -07:00
Alex Elder 07aa155878 libceph: activate message data assignment checks
The mds client no longer tries to assign zero-length message data,
and the osd client no longer sets its data info more than once.
This allows us to activate assertions in the messenger to verify
these things never happen.

This resolves both of these:
    http://tracker.ceph.com/issues/4263
    http://tracker.ceph.com/issues/4284

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-01 21:16:44 -07:00
Alex Elder 70636773b7 libceph: set response data fields earlier
When an incoming message is destined for the osd client, the
messenger calls the osd client's alloc_msg method.  That function
looks up which request has the tid matching the incoming message,
and returns the request message that was preallocated to receive the
response.  The response message is therefore known before the
request is even started.

Between the start of the request and the receipt of the response,
the request and its data fields will not change, so there's no
reason we need to hold off setting them.  In fact it's preferable
to set them just once because it's more obvious that they're
unchanging.

So set up the fields describing where incoming data is to land in a
response message at the beginning of ceph_osdc_start_request().
Define a helper function that sets these fields, and use it to
set the fields for both outgoing data in the request message and
incoming data in the response.

This resolves:
    http://tracker.ceph.com/issues/4284

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:43 -07:00
Alex Elder 4a73ef27ad libceph: record message data byte length
Record the number of bytes of data in a page array rather than the
number of pages in the array.  It can be assumed that the page array
is of sufficient size to hold the number of bytes indicated (and
offset by the indicated alignment).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:42 -07:00
Alex Elder ebf18f4709 ceph: only set message data pointers if non-empty
Change it so we only assign outgoing data information for messages
if there is outgoing data to send.

This then allows us to add a few more (currently commented-out)
assertions.

This is related to:
    http://tracker.ceph.com/issues/4284

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-01 21:16:41 -07:00
Alex Elder 27fa83852b libceph: isolate other message data fields
Define ceph_msg_data_set_pagelist(), ceph_msg_data_set_bio(), and
ceph_msg_data_set_trail() to clearly abstract the assignment of the
remaining data-related fields in a ceph message structure.  Use the
new functions in the osd client and mds client.

This partially resolves:
    http://tracker.ceph.com/issues/4263

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:40 -07:00
Alex Elder f1baeb2b9f libceph: set page info with byte length
When setting page array information for message data, provide the
byte length rather than the page count ceph_msg_data_set_pages().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:39 -07:00
Alex Elder 02afca6ca0 libceph: isolate message page field manipulation
Define a function ceph_msg_data_set_pages(), which more clearly
abstracts the assignment page-related fields for data in a ceph
message structure.  Use this new function in the osd client and mds
client.

Ideally, these fields would never be set more than once (with
BUG_ON() calls to guarantee that).  At the moment though the osd
client sets these every time it receives a message, and in the event
of a communication problem this can happen more than once.  (This
will be resolved shortly, but setting up these helpers first makes
it all a bit easier to work with.)

Rearrange the field order in a ceph_msg structure to group those
that are used to define the possible data payloads.

This partially resolves:
    http://tracker.ceph.com/issues/4263

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:38 -07:00
Alex Elder e0c594878e libceph: record byte count not page count
Record the byte count for an osd request rather than the page count.
The number of pages can always be derived from the byte count (and
alignment/offset) but the reverse is not true.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:36 -07:00
Alex Elder 9516e45b25 libceph: simplify new message initialization
Rather than explicitly initializing many fields to 0, NULL, or false
in a newly-allocated message, just use kzalloc() for allocating new
messages.  This will become a much more convenient way of doing
things anyway for upcoming patches that abstract the data field.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:35 -07:00
Alex Elder 35c7bfbcd4 libceph: advance pagelist with list_rotate_left()
While processing an outgoing pagelist (either the data pagelist or
trail) in a ceph message, the messenger cycles through each of the
pages on the list.  This is accomplished in out_msg_pos_next(), if
the end of the first page on the list is reached, the first page is
moved to the end of the list.

There is a list operation, list_rotate_left(), which performs
exactly this operation, and by using it, what's really going on
becomes more obvious.

So replace these two list_move_tail() calls with list_rotate_left().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:34 -07:00
Alex Elder e788182fa6 libceph: define and use in_msg_pos_next()
Define a new function in_msg_pos_next() to match out_msg_pos_next(),
and use it in place of code at the end of read_partial_message_pages()
and read_partial_message_bio().

Note that the page number is incremented and offset reset under
slightly different conditions from before.  The result is
equivalent, however, as explained below.

Each time an incoming message is going to arrive, we find out how
much room is left--not surpassing the current page--and provide that
as the number of bytes to receive.  So the amount we'll use is the
lesser of:  all that's left of the entire request; and all that's
left in the current page.

If we received exactly how many were requested, we either reached
the end of the request or the end of the page.  In the first case,
we're done, in the second, we move onto the next page in the array.

In all cases but (possibly) on the last page, after adding the
number of bytes received, page_pos == PAGE_SIZE.  On the last page,
it doesn't really matter whether we increment the page number and
reset the page position, because we're done and we won't come back
here again.  The code previously skipped over that last case,
basically.  The new code handles that case the same as the others,
incrementing and resetting.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:33 -07:00
Alex Elder b3d56fab33 libceph: kill args in read_partial_message_bio()
There is only one caller for read_partial_message_bio(), and it
always passes &msg->bio_iter and &bio_seg as the second and third
arguments.  Furthermore, the message in question is always the
connection's in_msg, and we can get that inside the called function.

So drop those two parameters and use their derived equivalents.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:32 -07:00
Alex Elder e1dcb128f8 libceph: change type of ceph_tcp_sendpage() "more"
Change the type of the "more" parameter from int to bool.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:31 -07:00
Alex Elder 6ebc8b32b3 libceph: minor byte order problems in read_partial_message()
Some values printed are not (necessarily) in CPU order.  We already
have a copy of the converted versions, so use them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:30 -07:00
Alex Elder 7b11ba3758 libceph: define CEPH_MSG_MAX_MIDDLE_LEN
This is probably unnecessary but the code read as if it were wrong
in read_partial_message().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:29 -07:00
Alex Elder 4137577ae3 libceph: clean up skipped message logic
In ceph_con_in_msg_alloc() it is possible for a connection's
alloc_msg method to indicate an incoming message should be skipped.
By default, read_partial_message() initializes the skip variable
to 0 before it gets provided to ceph_con_in_msg_alloc().

The osd client, mon client, and mds client each supply an alloc_msg
method.  The mds client always assigns skip to be 0.

The other two leave the skip value of as-is, or assigns it to zero,
except:
    - if no (osd or mon) request having the given tid is found, in
      which case skip is set to 1 and NULL is returned; or
    - in the osd client, if the data of the reply message is not
      adequate to hold the message to be read, it assigns skip
      value 1 and returns NULL.
So the returned message pointer will always be NULL if skip is ever
non-zero.

Clean up the logic a bit in ceph_con_in_msg_alloc() to make this
state of affairs more obvious.  Add a comment explaining how a null
message pointer can mean either a message that should be skipped or
a problem allocating a message.

This resolves:
    http://tracker.ceph.com/issues/4324

Reported-by: Greg Farnum <greg@inktank.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-01 21:16:28 -07:00
Alex Elder 0fff87ec79 libceph: separate read and write data
An osd request defines information about where data to be read
should be placed as well as where data to write comes from.
Currently these are represented by common fields.

Keep information about data for writing separate from data to be
read by splitting these into data_in and data_out fields.

This is the key patch in this whole series, in that it actually
identifies which osd requests generate outgoing data and which
generate incoming data.  It's less obvious (currently) that an osd
CALL op generates both outgoing and incoming data; that's the focus
of some upcoming work.

This resolves:
    http://tracker.ceph.com/issues/4127

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:27 -07:00
Alex Elder 2ac2b7a6d4 libceph: distinguish page and bio requests
An osd request uses either pages or a bio list for its data.  Use a
union to record information about the two, and add a data type
tag to select between them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:25 -07:00
Alex Elder 2794a82a11 libceph: separate osd request data info
Pull the fields in an osd request structure that define the data for
the request out into a separate structure.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:24 -07:00
Alex Elder 153e5167e0 libceph: don't assign page info in ceph_osdc_new_request()
Currently ceph_osdc_new_request() assigns an osd request's
r_num_pages and r_alignment fields.  The only thing it does
after that is call ceph_osdc_build_request(), and that doesn't
need those fields to be assigned.

Move the assignment of those fields out of ceph_osdc_new_request()
and into its caller.  As a result, the page_align parameter is no
longer used, so get rid of it.

Note that in ceph_sync_write(), the value for req->r_num_pages had
already been calculated earlier (as num_pages, and fortunately
it was computed the same way).  So don't bother recomputing it,
but because it's not needed earlier, move that calculation after the
call to ceph_osdc_new_request().  Hold off making the assignment to
r_alignment, doing it instead r_pages and r_num_pages are
getting set.

Similarly, in start_read(), nr_pages already holds the number of
pages in the array (and is calculated the same way), so there's no
need to recompute it.  Move the assignment of the page alignment
down with the others there as well.

This and the next few patches are preparation work for:
    http://tracker.ceph.com/issues/4127

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:23 -07:00
Alex Elder 53ded495c6 libceph: define mds_alloc_msg() method
The only user of the ceph messenger that doesn't define an alloc_msg
method is the mds client.  Define one, such that it works just like
it did before, and simplify ceph_con_in_msg_alloc() by assuming the
alloc_msg method is always present.

This and the next patch resolve:
    http://tracker.ceph.com/issues/4322

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-01 21:16:19 -07:00
Alex Elder 1d866d1c31 libceph: drop mutex while allocating a message
In ceph_con_in_msg_alloc(), if no alloc_msg method is defined for a
connection a new message is allocated with ceph_msg_new().

Drop the mutex before making this call, and make sure we're still
connected when we get it back again.

This is preparing for the next patch, which ensures all connections
define an alloc_msg method, and then handles them all the same way.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-01 21:16:18 -07:00
Alex Elder 41766f87f5 libceph: rename ceph_calc_object_layout()
The purpose of ceph_calc_object_layout() is to fill in the pool
number and seed for a ceph_pg structure provided, based on a given
osd map and target object id.

Currently that function takes a file layout parameter, but the only
thing used out of that is its pool number.

Change the function so it takes a pool number rather than the full
file layout structure.  Only update the ceph_pg if the pool is found
in the osd map.  Get rid of few useless lines of code from the
function while there.

Since the function now very clearly just fills in the ceph_pg
structure it's provided, rename it ceph_calc_ceph_pg().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:17 -07:00
Alex Elder ec02a2f2ff libceph: kill ceph_msg->pagelist_count
The pagelist_count field is never actually used, so get rid of it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:16 -07:00
Alex Elder 8f63ca2d23 libceph: fix wrong opcode use in osd_req_encode_op()
The new cases added to osd_req_encode_op() caused a new sparse
error, which highlighted an existing problem that had been
overlooked since it was originally checked in.  When an unsupported
opcode is found the destination rather than the source opcode was
being used in the error message.  The two differ in their byte
order, and we want to be using the one in the source.

Fix the problem in both spots.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:13 -07:00
Alex Elder 0d5af16435 libceph: complete lingering requests only once
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/3967

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:12 -07:00
Alex Elder f51a822c31 libceph: set page alignment in start_request()
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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:29 -07:00
Alex Elder d4b515fa10 libceph: distinguish page array and pagelist count
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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:28 -07:00
Alex Elder 60cf5992d9 libceph: don't pass request to calc_layout()
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/4262

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:27 -07:00
Alex Elder dbe0fc4188 libceph: format target object name in caller
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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:26 -07:00
Alex Elder 47a05811b6 libceph: pass object number back to calc_layout() caller
Have calc_layout() pass the computed object number back to its
caller.  (This is a small step to simplify review.)

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:25 -07:00
Alex Elder 07c09b7255 libceph: make ceph_msg->bio_seg be unsigned
The bio_seg field is used by the ceph messenger in iterating through
a bio.  It should never have a negative value, so make it an
unsigned.  (I contemplated making it unsigned short to match the
struct bio definition, but it offered no benefit.)

Change variables used to hold bio_seg values to all be unsigned as
well.  Change two variable names in init_bio_iter() to match the
convention used everywhere else.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:23 -07:00