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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>
2013-05-01libceph: 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>
2013-05-01libceph: 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>
2013-05-01libceph: 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>
2013-05-01libceph: 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: 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>
2013-05-01libceph: 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>
2013-05-01libceph: 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>
2013-05-01libceph: 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>
2013-05-01libceph: get rid of read helpersAlex Elder
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>
2013-05-01libceph: no outbound zero dataAlex Elder
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>
2013-05-01libceph: use cursor for inbound data pagesAlex Elder
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>
2013-05-01libceph: kill ceph message bio_iter, bio_segAlex Elder
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>
2013-05-01libceph: use cursor for bio readsAlex Elder
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>
2013-05-01libceph: record residual bytes for all message data typesAlex Elder
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>
2013-05-01libceph: drop pages parameterAlex Elder
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>
2013-05-01libceph: initialize data fields on last msg putAlex Elder
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>
2013-05-01libceph: send queued requests when starting new oneAlex Elder
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>
2013-05-01libceph: keep request lists in tid orderAlex Elder
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>
2013-05-01libceph: requeue only sent requests when kickingAlex Elder
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>
2013-05-01libceph: no more kick_requests() raceAlex Elder
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>
2013-05-01libceph: slightly defer registering osd requestAlex Elder
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>