Rather than having a ceph message data item point to the cursor it's
associated with, have the cursor point to a data item. This will
allow a message cursor to be used for more than one data item.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
A message will only be processing a single data item at a time, so
there's no need for each data item to have its own cursor.
Move the cursor embedded in the message data structure into the
message itself. To minimize the impact, keep the data->cursor
field, but make it be a pointer to the cursor in the message.
Move the definition of ceph_msg_data above ceph_msg_data_cursor so
the cursor can point to the data without a forward definition rather
than vice-versa.
This and the upcoming patches are part of:
http://tracker.ceph.com/issues/3761
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The bio is the only data item type that doesn't record its full
length. Fix that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
We know the length of our message buffers. If we get a message
that's too long, just dump it and ignore it. If skip was set
then con->in_msg won't be valid, so be careful not to dereference
a null pointer in the process.
This resolves:
http://tracker.ceph.com/issues/4664
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This patch:
15a0d7b libceph: record message data length
did not enclose some bio-specific code inside CONFIG_BLOCK as
it should have. Fix that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Finally! Convert the osd op data pointers into real structures, and
make the switch over to using them instead of having all ops share
the in and/or out data structures in the osd request.
Set up a new function to traverse the set of ops and release any
data associated with them (pages).
This and the patches leading up to it resolve:
http://tracker.ceph.com/issues/4657
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Still using the osd request r_data_in and r_data_out pointer, but
we're basically only referring to it via the data pointers in the
osd ops. And we're transferring that information to the request
or reply message only when the op indicates it's needed, in
osd_req_encode_op().
To avoid a forward reference, ceph_osdc_msg_data_set() was moved up
in the file.
Don't bother calling ceph_osd_data_init(), in ceph_osd_alloc(),
because the ops array will already be zeroed anyway.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This ends up being a rather large patch but what it's doing is
somewhat straightforward.
Basically, this is replacing two calls with one. The first of the
two calls is initializing a struct ceph_osd_data with data (either a
page array, a page list, or a bio list); the second is setting an
osd request op so it associates that data with one of the op's
parameters. In place of those two will be a single function that
initializes the op directly.
That means we sort of fan out a set of the needed functions:
- extent ops with pages data
- extent ops with pagelist data
- extent ops with bio list data
and
- class ops with page data for receiving a response
We also have define another one, but it's only used internally:
- class ops with pagelist data for request parameters
Note that we *still* haven't gotten rid of the osd request's
r_data_in and r_data_out fields. All the osd ops refer to them for
their data. For now, these data fields are pointers assigned to the
appropriate r_data_* field when these new functions are called.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
All calls of ceph_osdc_start_request() are preceded (in the case of
rbd, almost) immediately by a call to ceph_osdc_build_request().
Move the build calls at the top of ceph_osdc_start_request() out of
there and into the ceph_osdc_build_request(). Nothing prevents
moving these calls to the top of ceph_osdc_build_request(), either
(and we're going to want them there in the next patch) so put them
at the top.
This and the next patch are related to:
http://tracker.ceph.com/issues/4657
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This simply moves ceph_osdc_build_request() later in its source
file without any change. Done as a separate patch to facilitate
review of the change in the next patch.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An object class method is formatted using a pagelist which contains
the class name, the method name, and the data concatenated into an
osd request's outbound data.
Currently when a class op is initialized in osd_req_op_cls_init(),
the lengths of and pointers to these three items are recorded.
Later, when the op is getting formatted into the request message, a
new pagelist is created and that is when these items get copied into
the pagelist.
This patch makes it so the pagelist to hold these items is created
when the op is initialized instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An osd request now holds all of its source op structures, and every
place that initializes one of these is in fact initializing one
of the entries in the the osd request's array.
So rather than supplying the address of the op to initialize, have
caller specify the osd request and an indication of which op it
would like to initialize. This better hides the details the
op structure (and faciltates moving the data pointers they use).
Since osd_req_op_init() is a common routine, and it's not used
outside the osd client code, give it static scope. Also make
it return the address of the specified op (so all the other
init routines don't have to repeat that code).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An extent type osd operation currently implies that there will
be corresponding data supplied in the data portion of the request
(for write) or response (for read) message. Similarly, an osd class
method operation implies a data item will be supplied to receive
the response data from the operation.
Add a ceph_osd_data pointer to each of those structures, and assign
it to point to eithre the incoming or the outgoing data structure in
the osd message. The data is not always available when an op is
initially set up, so add two new functions to allow setting them
after the op has been initialized.
Begin to make use of the data item pointer available in the osd
operation rather than the request data in or out structure in
places where it's convenient. Add some assertions to verify
pointers are always set the way they're expected to be.
This is a sort of stepping stone toward really moving the data
into the osd request ops, to allow for some validation before
making that jump.
This is the first in a series of patches that resolve:
http://tracker.ceph.com/issues/4657
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There are fields "indata" and "indata_len" defined the ceph osd
request op structure. The "in" part is with from the point of view
of the osd server, but is a little confusing here on the client
side. Change their names to use "request" instead of "in" to
indicate that it defines data provided with the request (as opposed
the data returned in the response).
Rename the local variable in osd_req_encode_op() to match.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An osd request keeps a pointer to the osd operations (ops) array
that it builds in its request message.
In order to allow each op in the array to have its own distinct
data, we will need to keep track of each op's data, and that
information does not go over the wire.
As long as we're tracking the data we might as well just track the
entire (source) op definition for each of the ops. And if we're
doing that, we'll have no more need to keep a pointer to the
wire-encoded version.
This patch makes the array of source ops be kept with the osd
request structure, and uses that instead of the version encoded in
the message in places where that was previously used. The array
will be embedded in the request structure, and the maximum number of
ops we ever actually use is currently 2. So reduce CEPH_OSD_MAX_OP
to 2 to reduce the size of the structure.
The result of doing this sort of ripples back up, and as a result
various function parameters and local variables become unnecessary.
Make r_num_ops be unsigned, and move the definition of struct
ceph_osd_req_op earlier to ensure it's defined where needed.
It does not yet add per-op data, that's coming soon.
This resolves:
http://tracker.ceph.com/issues/4656
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Alex Elder