summaryrefslogtreecommitdiff
path: root/net/ceph/messenger.c
AgeCommit message (Collapse)AuthorFilesLines
2013-05-02libceph: more cleanup of write_partial_msg_pages()Alex Elder1-14/+7
Basically all cases in write_partial_msg_pages() use the cursor, and as a result we can simplify that function quite a bit. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: kill message trailAlex Elder1-39/+5
The wart that is the ceph message trail can now be removed, because its only user was the osd client, and the previous patch made that no longer the case. The result allows write_partial_msg_pages() to be simplified considerably. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: implement pages array cursorAlex Elder1-4/+89
Implement and use cursor routines for page array message data items for outbound message data. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: implement bio message data item cursorAlex Elder1-21/+116
Implement and use cursor routines for bio message data items for outbound message data. (See the previous commit for reasoning in support of the changes in out_msg_pos_next().) Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: use data cursor for message pagelistAlex Elder1-12/+13
Switch to using the message cursor for the (non-trail) outgoing pagelist data item in a message if present. Notes on the logic changes in out_msg_pos_next(): - only the mds client uses a ceph pagelist for message data; - if the mds client ever uses a pagelist, it never uses a page array (or anything else, for that matter) for data in the same message; - only the osd client uses the trail portion of a message data, and when it does, it never uses any other data fields for outgoing data in the same message; and finally - only the rbd client uses bio message data (never pagelist). Therefore out_msg_pos_next() can assume: - if we're in the trail portion of a message, the message data pagelist, data, and bio can be ignored; and - if there is a page list, there will never be any a bio or page array data, and vice-versa. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: prepare for other message data item typesAlex Elder1-24/+93
This just inserts some infrastructure in preparation for handling other types of ceph message data items. No functional changes, just trying to simplify review by separating out some noise. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: start defining message data cursorAlex Elder1-10/+128
This patch lays out the foundation for using generic routines to manage processing items of message data. For simplicity, we'll start with just the trail portion of a message, because it stands alone and is only present for outgoing data. First some basic concepts. We'll use the term "data item" to represent one of the ceph_msg_data structures associated with a message. There are currently four of those, with single-letter field names p, l, b, and t. A data item is further broken into "pieces" which always lie in a single page. A data item will include a "cursor" that will track state as the memory defined by the item is consumed by sending data from or receiving data into it. We define three routines to manipulate a data item's cursor: the "init" routine; the "next" routine; and the "advance" routine. The "init" routine initializes the cursor so it points at the beginning of the first piece in the item. The "next" routine returns the page, page offset, and length (limited by both the page and item size) of the next unconsumed piece in the item. It also indicates to the caller whether the piece being returned is the last one in the data item. The "advance" routine consumes the requested number of bytes in the item (advancing the cursor). This is used to record the number of bytes from the current piece that were actually sent or received by the network code. It returns an indication of whether the result means the current piece has been fully consumed. This is used by the message send code to determine whether it should calculate the CRC for the next piece processed. The trail of a message is implemented as a ceph pagelist. The routines defined for it will be usable for non-trail pagelist data as well. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: abstract message dataAlex Elder1-10/+23
Group the types of message data into an abstract structure with a type indicator and a union containing fields appropriate to the type of data it represents. Use this to represent the pages, pagelist, bio, and trail in a ceph message. Verify message data is of type NONE in ceph_msg_data_set_*() routines. Since information about message data of type NONE really should not be interpreted, get rid of the other assertions in those functions. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: be explicit about message data representationAlex Elder1-34/+34
A ceph message has a data payload portion. The memory for that data (either the source of data to send or the location to place data that is received) is specified in several ways. The ceph_msg structure includes fields for all of those ways, but this mispresents the fact that not all of them are used at a time. Specifically, the data in a message can be in: - an array of pages - a list of pages - a list of Linux bios - a second list of pages (the "trail") (The two page lists are currently only ever used for outgoing data.) Impose more structure on the ceph message, making the grouping of some of these fields explicit. Shorten the name of the "page_alignment" field. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: define ceph_msg_has_*() data macrosAlex Elder1-17/+27
Define and use macros ceph_msg_has_*() to determine whether to operate on the pages, pagelist, bio, and trail fields of a message. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: define and use ceph_crc32c_page()Alex Elder1-27/+20
Factor out a common block of code that updates a CRC calculation over a range of data in a page. This and the preceding patches are related to: http://tracker.ceph.com/issues/4403 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: define and use ceph_tcp_recvpage()Alex Elder1-26/+60
Define a new function ceph_tcp_recvpage() that behaves in a way comparable to ceph_tcp_sendpage(). Rearrange the code in both read_partial_message_pages() and read_partial_message_bio() so they have matching structure, (similar to what's in write_partial_msg_pages()), and use this new function. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: encapsulate reading message dataAlex Elder1-22/+41
Pull the code that reads the data portion into a message into a separate function read_partial_msg_data(). Rename write_partial_msg_pages() to be write_partial_message_data() to match its read counterpart, and to reflect its more generic purpose. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: small write_partial_msg_pages() refactorAlex Elder1-8/+9
Define local variables page_offset and length to represent the range of bytes within a page that will be sent by ceph_tcp_sendpage() in write_partial_msg_pages(). Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: consolidate message prep codeAlex Elder1-18/+10
In prepare_write_message_data(), various fields are initialized in preparation for writing message data out. Meanwhile, in read_partial_message(), there is essentially the same block of code, operating on message variables associated with an incoming message. Generalize prepare_write_message_data() so it works for both incoming and outcoming messages, and use it in both spots. The did_page_crc is not used for input (so it's harmless to initialize it). Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: use local variables for message positionsAlex Elder1-39/+46
There are several places where a message's out_msg_pos or in_msg_pos field is used repeatedly within a function. Use a local pointer variable for this purpose to unclutter the code. This and the upcoming cleanup patches are related to: http://tracker.ceph.com/issues/4403 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: don't clear bio_iter in prepare_write_message()Alex Elder1-4/+0
At one time it was necessary to clear a message's bio_iter field to avoid a bad pointer dereference in write_partial_msg_pages(). That no longer seems to be the case. Here's why. The message's bio fields represent (in this case) outgoing data. Between where the bio_iter is made NULL in prepare_write_message() and the call in that function to prepare_message_data(), the bio fields are never used. In prepare_message_data(), init-bio_iter() is called, and the result of that overwrites the value in the message's bio_iter field. Because it gets overwritten anyway, there is no need to set it to NULL. So don't do it. This resolves: http://tracker.ceph.com/issues/4402 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: activate message data assignment checksAlex Elder1-12/+12
The mds client no longer tries to assign zero-length message data, and the osd client no longer sets its data info more than once. This allows us to activate assertions in the messenger to verify these things never happen. This resolves both of these: http://tracker.ceph.com/issues/4263 http://tracker.ceph.com/issues/4284 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-02libceph: record message data byte lengthAlex Elder1-11/+9
Record the number of bytes of data in a page array rather than the number of pages in the array. It can be assumed that the page array is of sufficient size to hold the number of bytes indicated (and offset by the indicated alignment). Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02ceph: only set message data pointers if non-emptyAlex Elder1-0/+4
Change it so we only assign outgoing data information for messages if there is outgoing data to send. This then allows us to add a few more (currently commented-out) assertions. This is related to: http://tracker.ceph.com/issues/4284 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-02libceph: isolate other message data fieldsAlex Elder1-0/+28
Define ceph_msg_data_set_pagelist(), ceph_msg_data_set_bio(), and ceph_msg_data_set_trail() to clearly abstract the assignment of the remaining data-related fields in a ceph message structure. Use the new functions in the osd client and mds client. This partially resolves: http://tracker.ceph.com/issues/4263 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: set page info with byte lengthAlex Elder1-2/+2
When setting page array information for message data, provide the byte length rather than the page count ceph_msg_data_set_pages(). Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: isolate message page field manipulationAlex Elder1-0/+11
Define a function ceph_msg_data_set_pages(), which more clearly abstracts the assignment page-related fields for data in a ceph message structure. Use this new function in the osd client and mds client. Ideally, these fields would never be set more than once (with BUG_ON() calls to guarantee that). At the moment though the osd client sets these every time it receives a message, and in the event of a communication problem this can happen more than once. (This will be resolved shortly, but setting up these helpers first makes it all a bit easier to work with.) Rearrange the field order in a ceph_msg structure to group those that are used to define the possible data payloads. This partially resolves: http://tracker.ceph.com/issues/4263 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: simplify new message initializationAlex Elder1-34/+4
Rather than explicitly initializing many fields to 0, NULL, or false in a newly-allocated message, just use kzalloc() for allocating new messages. This will become a much more convenient way of doing things anyway for upcoming patches that abstract the data field. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: advance pagelist with list_rotate_left()Alex Elder1-4/+2
While processing an outgoing pagelist (either the data pagelist or trail) in a ceph message, the messenger cycles through each of the pages on the list. This is accomplished in out_msg_pos_next(), if the end of the first page on the list is reached, the first page is moved to the end of the list. There is a list operation, list_rotate_left(), which performs exactly this operation, and by using it, what's really going on becomes more obvious. So replace these two list_move_tail() calls with list_rotate_left(). Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: define and use in_msg_pos_next()Alex Elder1-20/+37
Define a new function in_msg_pos_next() to match out_msg_pos_next(), and use it in place of code at the end of read_partial_message_pages() and read_partial_message_bio(). Note that the page number is incremented and offset reset under slightly different conditions from before. The result is equivalent, however, as explained below. Each time an incoming message is going to arrive, we find out how much room is left--not surpassing the current page--and provide that as the number of bytes to receive. So the amount we'll use is the lesser of: all that's left of the entire request; and all that's left in the current page. If we received exactly how many were requested, we either reached the end of the request or the end of the page. In the first case, we're done, in the second, we move onto the next page in the array. In all cases but (possibly) on the last page, after adding the number of bytes received, page_pos == PAGE_SIZE. On the last page, it doesn't really matter whether we increment the page number and reset the page position, because we're done and we won't come back here again. The code previously skipped over that last case, basically. The new code handles that case the same as the others, incrementing and resetting. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: kill args in read_partial_message_bio()Alex Elder1-6/+6
There is only one caller for read_partial_message_bio(), and it always passes &msg->bio_iter and &bio_seg as the second and third arguments. Furthermore, the message in question is always the connection's in_msg, and we can get that inside the called function. So drop those two parameters and use their derived equivalents. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: change type of ceph_tcp_sendpage() "more"Alex Elder1-3/+3
Change the type of the "more" parameter from int to bool. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: minor byte order problems in read_partial_message()Alex Elder1-1/+1
Some values printed are not (necessarily) in CPU order. We already have a copy of the converted versions, so use them. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: define CEPH_MSG_MAX_MIDDLE_LENAlex Elder1-1/+1
This is probably unnecessary but the code read as if it were wrong in read_partial_message(). Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: clean up skipped message logicAlex Elder1-10/+13
In ceph_con_in_msg_alloc() it is possible for a connection's alloc_msg method to indicate an incoming message should be skipped. By default, read_partial_message() initializes the skip variable to 0 before it gets provided to ceph_con_in_msg_alloc(). The osd client, mon client, and mds client each supply an alloc_msg method. The mds client always assigns skip to be 0. The other two leave the skip value of as-is, or assigns it to zero, except: - if no (osd or mon) request having the given tid is found, in which case skip is set to 1 and NULL is returned; or - in the osd client, if the data of the reply message is not adequate to hold the message to be read, it assigns skip value 1 and returns NULL. So the returned message pointer will always be NULL if skip is ever non-zero. Clean up the logic a bit in ceph_con_in_msg_alloc() to make this state of affairs more obvious. Add a comment explaining how a null message pointer can mean either a message that should be skipped or a problem allocating a message. This resolves: http://tracker.ceph.com/issues/4324 Reported-by: Greg Farnum <greg@inktank.com> Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-02libceph: define mds_alloc_msg() methodAlex Elder1-40/+19
The only user of the ceph messenger that doesn't define an alloc_msg method is the mds client. Define one, such that it works just like it did before, and simplify ceph_con_in_msg_alloc() by assuming the alloc_msg method is always present. This and the next patch resolve: http://tracker.ceph.com/issues/4322 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-02libceph: drop mutex while allocating a messageAlex Elder1-4/+10
In ceph_con_in_msg_alloc(), if no alloc_msg method is defined for a connection a new message is allocated with ceph_msg_new(). Drop the mutex before making this call, and make sure we're still connected when we get it back again. This is preparing for the next patch, which ensures all connections define an alloc_msg method, and then handles them all the same way. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-02libceph: kill ceph_msg->pagelist_countAlex Elder1-2/+0
The pagelist_count field is never actually used, so get rid of it. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: distinguish page array and pagelist countAlex Elder1-6/+8
Use distinct fields for tracking the number of pages in a message's page array and in a message's page list. Currently only one or the other is used at a time, but that will be changing soon. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02libceph: make ceph_msg->bio_seg be unsignedAlex Elder1-7/+9
The bio_seg field is used by the ceph messenger in iterating through a bio. It should never have a negative value, so make it an unsigned. (I contemplated making it unsigned short to match the struct bio definition, but it offered no benefit.) Change variables used to hold bio_seg values to all be unsigned as well. Change two variable names in init_bio_iter() to match the convention used everywhere else. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-02-26libceph: use a do..while loop in con_work()Alex Elder1-41/+42
This just converts a manually-implemented loop into a do..while loop in con_work(). It also moves handling of EAGAIN inside the blocks where it's already been determined an error code was returned. Also update a few dout() calls near the affected code for consistency. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-02-26libceph: use a flag to indicate a fault has occurredAlex Elder1-12/+12
This just rearranges the logic in con_work() a little bit so that a flag is used to indicate a fault has occurred. This allows both the fault and non-fault case to be handled the same way and avoids a couple of nearly consecutive gotos. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-02-26libceph: separate non-locked fault handlingAlex Elder1-19/+23
An error occurring on a ceph connection is treated as a fault, causing the connection to be reset. The initial part of this fault handling has to be done while holding the connection mutex, but it must then be dropped for the last part. Separate the part of this fault handling that executes without the lock into its own function, con_fault_finish(). Move the call to this new function, as well as call that drops the connection mutex, into ceph_fault(). Rename that function con_fault() to reflect that it's only handling the connection part of the fault handling. The motivation for this was a warning from sparse about the locking being done here. Rearranging things this way keeps all the mutex manipulation within ceph_fault(), and this stops sparse from complaining. This partially resolves: http://tracker.ceph.com/issues/4184 Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-02-26libceph: encapsulate connection backoffAlex Elder1-13/+24
Collect the code that tests for and implements a backoff delay for a ceph connection into a new function, ceph_backoff(). Make the debug output messages in that part of the code report things consistently by reporting a message in the socket closed case, and by making the one for PREOPEN state report the connection pointer like the rest. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-02-26libceph: eliminate sparse warningsAlex Elder1-1/+1
Eliminate most of the problems in the libceph code that cause sparse to issue warnings. - Convert functions that are never referenced externally to have static scope. - Pass NULL rather than 0 for a pointer argument in one spot in ceph_monc_delete_snapid() This partially resolves: http://tracker.ceph.com/issues/4184 Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-02-26libceph: define connection flag helpersAlex Elder1-29/+78
Define and use functions that encapsulate operations performed on a connection's flags. This resolves: http://tracker.ceph.com/issues/4234 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-02-14libceph: fix messenger CONFIG_BLOCK dependenciesAlex Elder1-1/+4
The ceph messenger has a few spots that are only used when bio messages are supported, and that's only when CONFIG_BLOCK is defined. This surrounds a couple of spots with #ifdef's that would cause a problem if CONFIG_BLOCK were not present in the kernel configuration. This resolves: http://tracker.ceph.com/issues/3976 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-12-28libceph: fix protocol feature mismatch failure pathSage Weil1-10/+4
We should not set con->state to CLOSED here; that happens in ceph_fault() in the caller, where it first asserts that the state is not yet CLOSED. Avoids a BUG when the features don't match. Since the fail_protocol() has become a trivial wrapper, replace calls to it with direct calls to reset_connection(). Signed-off-by: Sage Weil <sage@inktank.com> Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-28libceph: WARN, don't BUG on unexpected connection statesAlex Elder1-6/+5
A number of assertions in the ceph messenger are implemented with BUG_ON(), killing the system if connection's state doesn't match what's expected. At this point our state model is (evidently) not well understood enough for these assertions to trigger a BUG(). Convert all BUG_ON(con->state...) calls to be WARN_ON(con->state...) so we learn about these issues without killing the machine. We now recognize that a connection fault can occur due to a socket closure at any time, regardless of the state of the connection. So there is really nothing we can assert about the state of the connection at that point so eliminate that assertion. Reported-by: Ugis <ugis22@gmail.com> Tested-by: Ugis <ugis22@gmail.com> Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-20libceph: report connection fault with warningAlex Elder1-1/+1
When a connection's socket disconnects, or if there's a protocol error of some kind on the connection, a fault is signaled and the connection is reset (closed and reopened, basically). We currently get an error message on the log whenever this occurs. A ceph connection will attempt to reestablish a socket connection repeatedly if a fault occurs. This means that these error messages will get repeatedly added to the log, which is undesirable. Change the error message to be a warning, so they don't get logged by default. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17libceph: socket can close in any connection stateAlex Elder1-17/+30
A connection's socket can close for any reason, independent of the state of the connection (and without irrespective of the connection mutex). As a result, the connectino can be in pretty much any state at the time its socket is closed. Handle those other cases at the top of con_work(). Pull this whole block of code into a separate function to reduce the clutter. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com>
2012-10-27libceph: avoid NULL kref_put from NULL alloc_msg returnSage Weil1-1/+2
The ceph_on_in_msg_alloc() method calls the ->alloc_msg() helper which may return NULL. It also drops con->mutex while it allocates a message, which means that the connection state may change (e.g., get closed). If that happens, we clean up and bail out. Avoid calling ceph_msg_put() on a NULL return value and triggering a crash. This was observed when an ->alloc_msg() call races with a timeout that resends a zillion messages and resets the connection, and ->alloc_msg() returns NULL (because the request was resent to another target). Fixes http://tracker.newdream.net/issues/3342 Signed-off-by: Sage Weil <sage@inktank.com> Reviewed-by: Alex Elder <elder@inktank.com>
2012-10-10rbd: define common queue_con_delay()Alex Elder1-15/+23
This patch defines a single function, queue_con_delay() to call queue_delayed_work() for a connection. It basically generalizes what was previously queue_con() by adding the delay argument. queue_con() is now a simple helper that passes 0 for its delay. queue_con_delay() returns 0 if it queued work or an errno if it did not for some reason. If con_work() finds the BACKOFF flag set for a connection, it now calls queue_con_delay() to handle arranging to start again after a delay. Note about connection reference counts: con_work() only ever gets called as a work item function. At the time that work is scheduled, a reference to the connection is acquired, and the corresponding con_work() call is then responsible for dropping that reference before it returns. Previously, the backoff handling inside con_work() silently handed off its reference to delayed work it scheduled. Now that queue_con_delay() is used, a new reference is acquired for the newly-scheduled work, and the original reference is dropped by the con->ops->put() call at the end of the function. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com>
2012-10-10rbd: let con_work() handle backoffAlex Elder1-18/+2
Both ceph_fault() and con_work() include handling for imposing a delay before doing further processing on a faulted connection. The latter is used only if ceph_fault() is unable to. Instead, just let con_work() always be responsible for implementing the delay. After setting up the delay value, set the BACKOFF flag on the connection unconditionally and call queue_con() to ensure con_work() will get called to handle it. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com>