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2013-05-01libceph: set the data pointers when encoding opsAlex Elder
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>
2013-05-01libceph: combine initializing and setting osd dataAlex Elder
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>
2013-05-01libceph: set message data when building osd requestAlex Elder
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>
2013-05-01libceph: move ceph_osdc_build_request()Alex Elder
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>
2013-05-01libceph: format class info at init timeAlex Elder
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>
2013-05-01rbd: rearrange some code for consistencyAlex Elder
This patch just trivially moves around some code for consistency. In preparation for initializing osd request data fields in ceph_osdc_build_request(), I wanted to verify that rbd did in fact call that immediately before it called ceph_osdc_start_request(). It was true (although image requests are built in a group and then started as a group). But I made the changes here just to make it more obvious, by making all of the calls follow a common sequence: osd_req_op_<optype>_init(); ceph_osd_data_<type>_init() osd_req_op_<optype>_<datafield>() rbd_osd_req_format() ... ret = rbd_obj_request_submit() I moved the initialization of the callback for image object requests into rbd_img_request_fill_bio(), again, for consistency. To avoid a forward reference, I moved the definition of rbd_img_obj_callback() up in the file. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01rbd: separate initialization of osd dataAlex Elder
The osd data for a request is currently initialized inside rbd_osd_req_create(), but that assumes an object request's data belongs in the osd request's data in or data out field. There are only three places where requests with data are set up, and it turns out it's easier to call just the osd data init routines directly there rather than handling it in rbd_osd_req_create(). (The real motivation here is moving toward getting rid of the osd request in and out data fields.) Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01rbd: don't set data in rbd_osd_req_format_op()Alex Elder
Currently an object request has its osd request's data field set in rbd_osd_req_format_op(). That assumes a single osd op per object request, and that won't be the case for long. Move the code that sets this out and into the caller. Rename rbd_osd_req_format_op() to be just rbd_osd_req_format(), removing the notion that it's doing anything op-specific. This and the next patch resolve: http://tracker.ceph.com/issues/4658 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: specify osd op by index in requestAlex Elder
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>
2013-05-01libceph: add data pointers in osd op structuresAlex Elder
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>
2013-05-01libceph: rename data out field in osd request opAlex Elder
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>
2013-05-01libceph: keep source rather than message osd op arrayAlex Elder
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>
2013-05-01rbd: define rbd_osd_req_format_op()Alex Elder
Define rbd_osd_req_format_op(), which encapsulates formatting an osd op into an object request's osd request message. Only one op is supported right now. Stop calling ceph_osdc_build_request() in rbd_osd_req_create(). Instead, call rbd_osd_req_format_op() in each of the callers of rbd_osd_req_create(). This is to prepare for the next patch, in which the source ops for an osd request will be held in the osd request itself. Because of that, we won't have the source op to work with until after the request is created, so we can't format the op until then. This an the next patch resolve: http://tracker.ceph.com/issues/4656 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: a few more osd data cleanupsAlex Elder
These are very small changes that make use osd_data local pointers as shorthands for structures being operated on. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: define ceph_osd_data_length()Alex Elder
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>
2013-05-01libceph: define a few more helpersAlex Elder
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>
2013-05-01libceph: define osd data initialization helpersAlex Elder
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>
2013-05-01libceph: compute incoming bytes onceAlex Elder
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>
2013-05-01rbd: define inbound data size for method opsAlex Elder
When rbd creates an object request containing an object method call operation it is passing 0 for the size. I originally thought this was because the length was not needed for method calls, but I think it really should be supplied, to describe how much space is available to receive response data. So provide the supplied length. This resolves: http://tracker.ceph.com/issues/4659 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: provide data length when preparing messageAlex Elder
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>
2013-05-01ceph: build osd request message later for writepagesAlex Elder
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>
2013-05-01libceph: hold off building osd requestAlex Elder
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>
2013-05-01ceph: kill ceph alloc_page_vec()Alex Elder
There is a helper function alloc_page_vec() that, despite its generic sounding name depends heavily on an osd request structure being populated with certain information. There is only one place this function is used, and it ends up being a bit simpler to just open code what it does, so get rid of the helper. The real motivation for this is deferring building the of the osd request message, and this is a step in that direction. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01ceph: define ceph_writepages_osd_request()Alex Elder
Mostly for readability, define ceph_writepages_osd_request() and use it to allocate the osd request for ceph_writepages_start(). Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: don't build request in ceph_osdc_new_request()Alex Elder
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>
2013-05-01libceph: record message data lengthAlex Elder
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>
2013-05-01libceph: record length of bio list with bioAlex Elder
When assigning a bio pointer to an osd request, we don't have an efficient way of knowing the total length bytes in the bio list. That information is available at the point it's set up by the rbd code, so record it with the osd data when it's set. This and the next patch are related to maintaining the length of a message's data independent 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>
2013-05-01libceph: drop ceph_osd_request->r_con_filling_msgAlex Elder
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>
2013-05-01ceph: use page_offset() in ceph_writepages_start()Alex Elder
There's one spot in ceph_writepages_start() that open-codes what page_offset() does safely. Use the macro so we don't have to worry about wrapping. This resolves: http://tracker.ceph.com/issues/4648 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: define ceph_decode_pgid() only onceAlex Elder
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>
2013-05-01libceph: drop mutex on error in handle_reply()Alex Elder
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>
2013-05-01ceph: set up page array mempool with correct sizeAlex Elder
In create_fs_client() a memory pool is set up be used for arrays of pages that might be needed in ceph_writepages_start() if memory is tight. There are two problems with the way it's initialized: - The size provided is the number of pages we want in the array, but it should be the number of bytes required for that many page pointers. - The number of pages computed can end up being 0, while we will always need at least one page. This patch fixes both of these problems. This resolves the two simple problems defined in: http://tracker.ceph.com/issues/4603 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: use osd_req_op_extent_init()Alex Elder
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>
2013-05-01libceph: clean up ceph_osd_new_request()Alex Elder
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>
2013-05-01libceph: don't update op in calc_layout()Alex Elder
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>
2013-05-01libceph: pass offset and length out of calc_layout()Alex Elder
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>
2013-05-01libceph: define source request op functionsAlex Elder
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>
2013-05-01libceph: define osd_req_opcode_valid()Alex Elder
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>
2013-05-01ceph: move max constant definitionsAlex Elder
Move some definitions for max integer values out of the rbd code and into the more central "decode.h" header file. These really belong in a Linux (or libc) header somewhere, but I haven't gotten around to proposing that yet. This is in preparation for moving some code out of rbd.c and into the osd client. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01libceph: be explicit in masking bottom 16 bitsAlex Elder
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>
2013-05-01libceph: account for alignment in pages cursorAlex Elder
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>
2013-05-01libceph: page offset must be less than page sizeAlex Elder
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>
2013-05-01libceph: fix broken data length assertionsAlex Elder
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>
2013-05-01libceph: make message data be a pointerAlex Elder
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>
2013-05-01libceph: use only ceph_msg_data_advance()Alex Elder
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>
2013-05-01libceph: don't add to crc unless data sentAlex Elder
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>
2013-05-01libceph: kill last of ceph_msg_posAlex Elder
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>
2013-05-01libceph: kill most of ceph_msg_posAlex Elder
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>
2013-05-01libceph: use cursor resid for loop conditionAlex Elder
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>
2013-05-01libceph: collapse all data items into oneAlex Elder
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>