The cursor code for a page array selects the right page, page
offset, and length to use for a ceph_tcp_recvpage() call, so
we can use it to replace a block in read_partial_message_pages().
This partially resolves:
http://tracker.ceph.com/issues/4428
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The bio_iter and bio_seg fields in a message are no longer used, we
use the cursor instead. So get rid of them and the functions that
operate on them them.
This is related to:
http://tracker.ceph.com/issues/4428
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Replace the use of the information in con->in_msg_pos for incoming
bio data. The old in_msg_pos and the new cursor mechanism do
basically the same thing, just slightly differently.
The main functional difference is that in_msg_pos keeps track of the
length of the complete bio list, and assumed it was fully consumed
when that many bytes had been transferred. The cursor does not assume
a length, it simply consumes all bytes in the bio list. Because the
only user of bio data is the rbd client, and because the length of a
bio list provided by rbd client always matches the number of bytes
in the list, both ways of tracking length are equivalent.
In addition, for in_msg_pos the initial bio vector is selected as
the initial value of the bio->bi_idx, while the cursor assumes this
is zero. Again, the rbd client always passes 0 as the initial index
so the effect is the same.
Other than that, they basically match:
in_msg_pos cursor
---------- ------
bio_iter bio
bio_seg vec_index
page_pos page_offset
The in_msg_pos field is initialized by a call to init_bio_iter().
The bio cursor is initialized by ceph_msg_data_cursor_init().
Both now happen in the same spot, in prepare_message_data().
The in_msg_pos field is advanced by a call to in_msg_pos_next(),
which updates page_pos and calls iter_bio_next() to move to the next
bio vector, or to the next bio in the list. The cursor is advanced
by ceph_msg_data_advance(). That isn't currently happening so
add a call to that in in_msg_pos_next().
Finally, the next piece of data to use for a read is determined
by a bunch of lines in read_partial_message_bio(). Those can be
replaced by an equivalent ceph_msg_data_bio_next() call.
This partially resolves:
http://tracker.ceph.com/issues/4428
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
All of the data types can use this, not just the page array. Until
now, only the bio type doesn't have it available, and only the
initiator of the request (the rbd client) is able to supply the
length of the full request without re-scanning the bio list. Change
the cursor init routines so the length is supplied based on the
message header "data_len" field, and use that length to intiialize
the "resid" field of the cursor.
In addition, change the way "last_piece" is defined so it is based
on the residual number of bytes in the original request. This is
necessary (at least for bio messages) because it is possible for
a read request to succeed without consuming all of the space
available in the data buffer.
This resolves:
http://tracker.ceph.com/issues/4427
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
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>
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>
We maintain a counter of failed auth attempts to allow us to retry once
before failing. However, if the second attempt succeeds, the flag isn't
cleared, which makes us think auth failed again later when the connection
resets for other reasons (like a socket error).
This is one part of the sorry sequence of events in bug
http://tracker.ceph.com/issues/4282
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This is an old protocol extension that allows the client and server to
avoid resending old messages after a reconnect (following a socket error).
Instead, the exchange their sequence numbers during the handshake. This
avoids sending a bunch of useless data over the socket.
It has been supported in the server code since v0.22 (Sep 2010).
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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/4263http://tracker.ceph.com/issues/4284
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
If ceph_fault() is unable to queue work after a delay, it sets the
BACKOFF connection flag so con_work() will attempt to do so.
In con_work(), when BACKOFF is set, if queue_delayed_work() doesn't
result in newly-queued work, it simply ignores this condition and
proceeds as if no backoff delay were desired. There are two
problems with this--one of which is a bug.
The first problem is simply that the intended behavior is to back
off, and if we aren't able queue the work item to run after a delay
we're not doing that.
The only reason queue_delayed_work() won't queue work is if the
provided work item is already queued. In the messenger, this
means that con_work() is already scheduled to be run again. So
if we simply set the BACKOFF flag again when this occurs, we know
the next con_work() call will again attempt to hold off activity
on the connection until after the delay.
The second problem--the bug--is a leak of a reference count. If
queue_delayed_work() returns 0 in con_work(), con->ops->put() drops
the connection reference held on entry to con_work(). However,
processing is (was) allowed to continue, and at the end of the
function a second con->ops->put() is called.
This patch fixes both problems.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
In write_partial_msg_pages(), pages need to be kmapped in order to
perform a CRC-32c calculation on them. As an artifact of the way
this code used to be structured, the kunmap() call was separated
from the kmap() call and both were done conditionally. But the
conditions under which the kmap() and kunmap() calls were made
differed, so there was a chance a kunmap() call would be done on a
page that had not been mapped.
The symptom of this was tripping a BUG() in kunmap_high() when
pkmap_count[nr] became 0.
Reported-by: Bryan K. Wright <bryan@virginia.edu>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Because the Ceph client messenger uses a non-blocking connect, it is
possible for the sending of the client banner to race with the
arrival of the banner sent by the peer.
When ceph_sock_state_change() notices the connect has completed, it
schedules work to process the socket via con_work(). During this
time the peer is writing its banner, and arrival of the peer banner
races with con_work().
If con_work() calls try_read() before the peer banner arrives, there
is nothing for it to do, after which con_work() calls try_write() to
send the client's banner. In this case Ceph's protocol negotiation
can complete succesfully.
The server-side messenger immediately sends its banner and addresses
after accepting a connect request, *before* actually attempting to
read or verify the banner from the client. As a result, it is
possible for the banner from the server to arrive before con_work()
calls try_read(). If that happens, try_read() will read the banner
and prepare protocol negotiation info via prepare_write_connect().
prepare_write_connect() calls con_out_kvec_reset(), which discards
the as-yet-unsent client banner. Next, con_work() calls
try_write(), which sends the protocol negotiation info rather than
the banner that the peer is expecting.
The result is that the peer sees an invalid banner, and the client
reports "negotiation failed".
Fix this by moving con_out_kvec_reset() out of
prepare_write_connect() to its callers at all locations except the
one where the banner might still need to be sent.
[elder@inktak.com: added note about server-side behavior]
Signed-off-by: Jim Schutt <jaschut@sandia.gov>
Reviewed-by: Alex Elder <elder@inktank.com>
Pull Ceph changes from Sage Weil:
"Lots of stuff this time around:
- lots of cleanup and refactoring in the libceph messenger code, and
many hard to hit races and bugs closed as a result.
- lots of cleanup and refactoring in the rbd code from Alex Elder,
mostly in preparation for the layering functionality that will be
coming in 3.7.
- some misc rbd cleanups from Josh Durgin that are finally going
upstream
- support for CRUSH tunables (used by newer clusters to improve the
data placement)
- some cleanup in our use of d_parent that Al brought up a while back
- a random collection of fixes across the tree
There is another patch coming that fixes up our ->atomic_open()
behavior, but I'm going to hammer on it a bit more before sending it."
Fix up conflicts due to commits that were already committed earlier in
drivers/block/rbd.c, net/ceph/{messenger.c, osd_client.c}
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (132 commits)
rbd: create rbd_refresh_helper()
rbd: return obj version in __rbd_refresh_header()
rbd: fixes in rbd_header_from_disk()
rbd: always pass ops array to rbd_req_sync_op()
rbd: pass null version pointer in add_snap()
rbd: make rbd_create_rw_ops() return a pointer
rbd: have __rbd_add_snap_dev() return a pointer
libceph: recheck con state after allocating incoming message
libceph: change ceph_con_in_msg_alloc convention to be less weird
libceph: avoid dropping con mutex before fault
libceph: verify state after retaking con lock after dispatch
libceph: revoke mon_client messages on session restart
libceph: fix handling of immediate socket connect failure
ceph: update MAINTAINERS file
libceph: be less chatty about stray replies
libceph: clear all flags on con_close
libceph: clean up con flags
libceph: replace connection state bits with states
libceph: drop unnecessary CLOSED check in socket state change callback
libceph: close socket directly from ceph_con_close()
...
We drop the lock when calling the ->alloc_msg() con op, which means
we need to (a) not clobber con->in_msg without the mutex held, and (b)
we need to verify that we are still in the OPEN state when we retake
it to avoid causing any mayhem. If the state does change, -EAGAIN
will get us back to con_work() and loop.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This function's calling convention is very limiting. In particular,
we can't return any error other than ENOMEM (and only implicitly),
which is a problem (see next patch).
Instead, return an normal 0 or error code, and make the skip a pointer
output parameter. Drop the useless in_hdr argument (we have the con
pointer).
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
The ceph_fault() function takes the con mutex, so we should avoid
dropping it before calling it. This fixes a potential race with
another thread calling ceph_con_close(), or _open(), or similar (we
don't reverify con->state after retaking the lock).
Add annotation so that lockdep realizes we will drop the mutex before
returning.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
We drop the con mutex when delivering a message. When we retake the
lock, we need to verify we are still in the OPEN state before
preparing to read the next tag, or else we risk stepping on a
connection that has been closed.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
If the connect() call immediately fails such that sock == NULL, we
still need con_close_socket() to reset our socket state to CLOSED.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Rename flags with CON_FLAG prefix, move the definitions into the c file,
and (better) document their meaning.
Signed-off-by: Sage Weil <sage@inktank.com>
Use a simple set of 6 enumerated values for the socket states (CON_STATE_*)
and use those instead of the state bits. All of the con->state checks are
now under the protection of the con mutex, so this is safe. It also
simplifies many of the state checks because we can check for anything other
than the expected state instead of various bits for races we can think of.
This appears to hold up well to stress testing both with and without socket
failure injection on the server side.
Signed-off-by: Sage Weil <sage@inktank.com>
It is simpler to do this immediately, since we already hold the con mutex.
It also avoids the need to deal with a not-quite-CLOSED socket in con_work.
Signed-off-by: Sage Weil <sage@inktank.com>
Take the con mutex before checking whether the connection is closed to
avoid racing with someone else closing it.
Signed-off-by: Sage Weil <sage@inktank.com>
If we fault on a lossy connection, we should still close the socket
immediately, and do so under the con mutex.
We should also take the con mutex before printing out the state bits in
the debug output.
Signed-off-by: Sage Weil <sage@inktank.com>
We exponentially back off when we encounter connection errors. If several
errors accumulate, we will eventually wait ages before even trying to
reconnect.
Fix this by resetting the backoff counter after a successful negotiation/
connection with the remote node. Fixes ceph issue #2802.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Take the con mutex while we are initiating a ceph open. This is necessary
because the may have previously been in use and then closed, which could
result in a racing workqueue running con_work().
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Previously, we were opportunistically initializing the bio_iter if it
appeared to be uninitialized in the middle of the read path. The problem
is that a sequence like:
- start reading message
- initialize bio_iter
- read half a message
- messenger fault, reconnect
- restart reading message
- ** bio_iter now non-NULL, not reinitialized **
- read past end of bio, crash
Instead, initialize the bio_iter unconditionally when we allocate/claim
the message for read.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Hold the mutex while twiddling all of the state bits to avoid possible
races. While we're here, make not of why we cannot close the socket
directly.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
We need to set error_msg to something useful before calling ceph_fault();
do so here for try_{read,write}(). This is more informative than
libceph: osd0 192.168.106.220:6801 (null)
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Add an atomic variable 'stopping' as flag in struct ceph_messenger,
set this flag to 1 in function ceph_destroy_client(), and add the condition code
in function ceph_data_ready() to test the flag value, if true(1), just return.
Signed-off-by: Guanjun He <gjhe@suse.com>
Reviewed-by: Sage Weil <sage@inktank.com>
In ancient times, the messenger could both initiate and accept connections.
An artifact if that was data structures to store/process an incoming
ceph_msg_connect request and send an outgoing ceph_msg_connect_reply.
Sadly, the negotiation code was referencing those structures and ignoring
important information (like the peer's connect_seq) from the correct ones.
Among other things, this fixes tight reconnect loops where the server sends
RETRY_SESSION and we (the client) retries with the same connect_seq as last
time. This bug pretty easily triggered by injecting socket failures on the
MDS and running some fs workload like workunits/direct_io/test_sync_io.
Signed-off-by: Sage Weil <sage@inktank.com>
In ancient times, the messenger could both initiate and accept connections.
An artifact if that was data structures to store/process an incoming
ceph_msg_connect request and send an outgoing ceph_msg_connect_reply.
Sadly, the negotiation code was referencing those structures and ignoring
important information (like the peer's connect_seq) from the correct ones.
Among other things, this fixes tight reconnect loops where the server sends
RETRY_SESSION and we (the client) retries with the same connect_seq as last
time. This bug pretty easily triggered by injecting socket failures on the
MDS and running some fs workload like workunits/direct_io/test_sync_io.
Signed-off-by: Sage Weil <sage@inktank.com>
It is possible to close a socket that is in the OPENING state. For
example, it can happen if ceph_con_close() is called on the con before
the TCP connection is established. con_work() will come around and shut
down the socket.
Signed-off-by: Sage Weil <sage@inktank.com>
Sage liked the state diagram I put in my commit description so
I'm putting it in with the code.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
This patch gathers a few small changes in "net/ceph/messenger.c":
out_msg_pos_next()
- small logic change that mostly affects indentation
write_partial_msg_pages().
- use a local variable trail_off to represent the offset into
a message of the trail portion of the data (if present)
- once we are in the trail portion we will always be there, so we
don't always need to check against our data position
- avoid computing len twice after we've reached the trail
- get rid of the variable tmpcrc, which is not needed
- trail_off and trail_len never change so mark them const
- update some comments
read_partial_message_bio()
- bio_iovec_idx() will never return an error, so don't bother
checking for it
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Currently a ceph connection enters a "CONNECTING" state when it
begins the process of (re-)connecting with its peer. Once the two
ends have successfully exchanged their banner and addresses, an
additional NEGOTIATING bit is set in the ceph connection's state to
indicate the connection information exhange has begun. The
CONNECTING bit/state continues to be set during this phase.
Rather than have the CONNECTING state continue while the NEGOTIATING
bit is set, interpret these two phases as distinct states. In other
words, when NEGOTIATING is set, clear CONNECTING. That way only
one of them will be active at a time.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
There are two phases in the process of linking together the two ends
of a ceph connection. The first involves exchanging a banner and
IP addresses, and if that is successful a second phase exchanges
some detail about each side's connection capabilities.
When initiating a connection, the client side now queues to send
its information for both phases of this process at the same time.
This is probably a bit more efficient, but it is slightly messier
from a layering perspective in the code.
So rearrange things so that the client doesn't send the connection
information until it has received and processed the response in the
initial banner phase (in process_banner()).
Move the code (in the (con->sock == NULL) case in try_write()) that
prepares for writing the connection information, delaying doing that
until the banner exchange has completed. Move the code that begins
the transition to this second "NEGOTIATING" phase out of
process_banner() and into its caller, so preparing to write the
connection information and preparing to read the response are
adjacent to each other.
Finally, preparing to write the connection information now requires
the output kvec to be reset in all cases, so move that into the
prepare_write_connect() and delete it from all callers.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
There is no state explicitly defined when a ceph connection is fully
operational. So define one.
It's set when the connection sequence completes successfully, and is
cleared when the connection gets closed.
Be a little more careful when examining the old state when a socket
disconnect event is reported.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
A connection state's NEGOTIATING bit gets set while in CONNECTING
state after we have successfully exchanged a ceph banner and IP
addresses with the connection's peer (the server). But that bit
is not cleared again--at least not until another connection attempt
is initiated.
Instead, clear it as soon as the connection is fully established.
Also, clear it when a socket connection gets prematurely closed
in the midst of establishing a ceph connection (in case we had
reached the point where it was set).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
A connection that is closed will no longer be connecting. So
clear the CONNECTING state bit in ceph_con_close(). Similarly,
if the socket has been closed we no longer are in connecting
state (a new connect sequence will need to be initiated).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
In con_close_socket(), a connection's SOCK_CLOSED flag gets set and
then cleared while its shutdown method is called and its reference
gets dropped.
Previously, that flag got set only if it had not already been set,
so setting it in con_close_socket() might have prevented additional
processing being done on a socket being shut down. We no longer set
SOCK_CLOSED in the socket event routine conditionally, so setting
that bit here no longer provides whatever benefit it might have
provided before.
A race condition could still leave the SOCK_CLOSED bit set even
after we've issued the call to con_close_socket(), so we still clear
that bit after shutting the socket down. Add a comment explaining
the reason for this.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
When a TCP_CLOSE or TCP_CLOSE_WAIT event occurs, the SOCK_CLOSED
connection flag bit is set, and if it had not been previously set
queue_con() is called to ensure con_work() will get a chance to
handle the changed state.
con_work() atomically checks--and if set, clears--the SOCK_CLOSED
bit if it was set. This means that even if the bit were set
repeatedly, the related processing in con_work() only gets called
once per transition of the bit from 0 to 1.
What's important then is that we ensure con_work() gets called *at
least* once when a socket close event occurs, not that it gets
called *exactly* once.
The work queue mechanism already takes care of queueing work
only if it is not already queued, so there's no need for us
to call queue_con() conditionally.
So this patch just makes it so the SOCK_CLOSED flag gets set
unconditionally in ceph_sock_state_change().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Currently the socket state change event handler records an error
message on a connection to distinguish a close while connecting from
a close while a connection was already established.
Changing connection information during handling of a socket event is
not very clean, so instead move this assignment inside con_work(),
where it can be done during normal connection-level processing (and
under protection of the connection mutex as well).
Move the handling of a socket closed event up to the top of the
processing loop in con_work(); there's no point in handling backoff
etc. if we have a newly-closed socket to take care of.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
The following commit changed it so SOCK_CLOSED bit was stored in
a connection's new "flags" field rather than its "state" field.
libceph: start separating connection flags from state
commit 928443cd
That bit is used in con_close_socket() to protect against setting an
error message more than once in the socket event handler function.
Unfortunately, the field being operated on in that function was not
updated to be "flags" as it should have been. This fixes that
error.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Recently a bug was fixed in which the bio_iter field in a ceph
message was not being properly re-initialized when a message got
re-transmitted:
commit 43643528cc
Author: Yan, Zheng <zheng.z.yan@intel.com>
rbd: Clear ceph_msg->bio_iter for retransmitted message
We are now only initializing the bio_iter field when we are about to
start to write message data (in prepare_write_message_data()),
rather than every time we are attempting to write any portion of the
message data (in write_partial_msg_pages()). This means we no
longer need to use the msg->bio_iter field as a flag.
So just don't do that any more. Trust prepare_write_message_data()
to ensure msg->bio_iter is properly initialized, every time we are
about to begin writing (or re-writing) a message's bio data.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
If a message has a non-null bio pointer, its bio_iter field is
initialized in write_partial_msg_pages() if this has not been done
already. This is really a one-time setup operation for sending a
message's (bio) data, so move that initialization code into
prepare_write_message_data() which serves that purpose.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Move init_bio_iter() and iter_bio_next() up in their source file so
the'll be defined before they're needed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
