There are essentially two types of ceph messages: incoming and
outgoing. Outgoing messages are always allocated via ceph_msg_new(),
and at the time of their allocation they are not associated with any
particular connection. Incoming messages are always allocated via
ceph_con_in_msg_alloc(), and they are initially associated with the
connection from which incoming data will be placed into the message.
When an outgoing message gets sent, it becomes associated with a
connection and remains that way until the message is successfully
sent. The association of an incoming message goes away at the point
it is sent to an upper layer via a con->ops->dispatch method.
This patch implements reference counting for all ceph messages, such
that every message holds a reference (and a pointer) to a connection
if and only if it is associated with that connection (as described
above).
For background, here is an explanation of the ceph message
lifecycle, emphasizing when an association exists between a message
and a connection.
Outgoing Messages
An outgoing message is "owned" by its allocator, from the time it is
allocated in ceph_msg_new() up to the point it gets queued for
sending in ceph_con_send(). Prior to that point the message's
msg->con pointer is null; at the point it is queued for sending its
message pointer is assigned to refer to the connection. At that
time the message is inserted into a connection's out_queue list.
When a message on the out_queue list has been sent to the socket
layer to be put on the wire, it is transferred out of that list and
into the connection's out_sent list. At that point it is still owned
by the connection, and will remain so until an acknowledgement is
received from the recipient that indicates the message was
successfully transferred. When such an acknowledgement is received
(in process_ack()), the message is removed from its list (in
ceph_msg_remove()), at which point it is no longer associated with
the connection.
So basically, any time a message is on one of a connection's lists,
it is associated with that connection. Reference counting outgoing
messages can thus be done at the points a message is added to the
out_queue (in ceph_con_send()) and the point it is removed from
either its two lists (in ceph_msg_remove())--at which point its
connection pointer becomes null.
Incoming Messages
When an incoming message on a connection is getting read (in
read_partial_message()) and there is no message in con->in_msg,
a new one is allocated using ceph_con_in_msg_alloc(). At that
point the message is associated with the connection. Once that
message has been completely and successfully read, it is passed to
upper layer code using the connection's con->ops->dispatch method.
At that point the association between the message and the connection
no longer exists.
Reference counting of connections for incoming messages can be done
by taking a reference to the connection when the message gets
allocated, and releasing that reference when it gets handed off
using the dispatch method.
We should never fail to get a connection reference for a
message--the since the caller should already hold one.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
When a ceph message is queued for sending it is placed on a list of
pending messages (ceph_connection->out_queue). When they are
actually sent over the wire, they are moved from that list to
another (ceph_connection->out_sent). When acknowledgement for the
message is received, it is removed from the sent messages list.
During that entire time the message is "in the possession" of a
single ceph connection. Keep track of that connection in the
message. This will be used in the next patch (and is a helpful
bit of information for debugging anyway).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
The function ceph_alloc_msg() is only used to allocate a message
that will be assigned to a connection's in_msg pointer. Rename the
function so this implied usage is more clear.
In addition, make that assignment inside the function (again, since
that's precisely what it's intended to be used for). This allows us
to return what is now provided via the passed-in address of a "skip"
variable. The return type is now Boolean to be explicit that there
are only two possible outcomes.
Make sure the result of an ->alloc_msg method call always sets the
value of *skip properly.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Move the initialization of a ceph connection's private pointer,
operations vector pointer, and peer name information into
ceph_con_init(). Rearrange the arguments so the connection pointer
is first. Hide the byte-swapping of the peer entity number inside
ceph_con_init()
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Once a connection is fully initialized, it is really in a CLOSED
state, so make that explicit by setting the bit in its state field.
It is possible for a connection in NEGOTIATING state to get a
failure, leading to ceph_fault() and ultimately ceph_con_close().
Clear that bits if it is set in that case, to reflect that the
connection truly is closed and is no longer participating in a
connect sequence.
Issue a warning if ceph_con_open() is called on a connection that
is not in CLOSED state.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Start explicitly keeping track of the state of a ceph connection's
socket, separate from the state of the connection itself. Create
placeholder functions to encapsulate the state transitions.
--------
| NEW* | transient initial state
--------
| con_sock_state_init()
v
----------
| CLOSED | initialized, but no socket (and no
---------- TCP connection)
^ \
| \ con_sock_state_connecting()
| ----------------------
| \
+ con_sock_state_closed() \
|\ \
| \ \
| ----------- \
| | CLOSING | socket event; \
| ----------- await close \
| ^ |
| | |
| + con_sock_state_closing() |
| / \ |
| / --------------- |
| / \ v
| / --------------
| / -----------------| CONNECTING | socket created, TCP
| | / -------------- connect initiated
| | | con_sock_state_connected()
| | v
-------------
| CONNECTED | TCP connection established
-------------
Make the socket state an atomic variable, reinforcing that it's a
distinct transtion with no possible "intermediate/both" states.
This is almost certainly overkill at this point, though the
transitions into CONNECTED and CLOSING state do get called via
socket callback (the rest of the transitions occur with the
connection mutex held). We can back out the atomicity later.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil<sage@inktank.com>
A ceph_connection holds a mixture of connection state (as in "state
machine" state) and connection flags in a single "state" field. To
make the distinction more clear, define a new "flags" field and use
it rather than the "state" field to hold Boolean flag values.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil<sage@inktank.com>
A ceph client has a pointer to a ceph messenger structure in it.
There is always exactly one ceph messenger for a ceph client, so
there is no need to allocate it separate from the ceph client
structure.
Switch the ceph_client structure to embed its ceph_messenger
structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
The functions ceph_con_out_kvec_reset() and ceph_con_out_kvec_add()
are entirely private functions, so drop the "ceph_" prefix in their
name to make them slightly more wieldy.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Change the names of the three socket callback functions to make it
more obvious they're specifically associated with a connection's
socket (not the ceph connection that uses it).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
No code sets a bad_proto method in its ceph connection operations
vector, so just get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
The ceph connection state "DEAD" is never set and is therefore not
needed. Eliminate it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Move the addition of the authorizer buffer to a connection's
out_kvec out of get_connect_authorizer() and into its caller. This
way, the caller--prepare_write_connect()--can avoid adding the
connect header to out_kvec before it has been fully initialized.
Prior to this patch, it was possible for a connect header to be
sent over the wire before the authorizer protocol or buffer length
fields were initialized. An authorizer buffer associated with that
header could also be queued to send only after the connection header
that describes it was on the wire.
Fixes http://tracker.newdream.net/issues/2424
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Change the name of prepare_connect_authorizer(). The next
patch is going to make this function no longer add anything to the
connection's out_kvec, so it will no longer fit the pattern of
the rest of the prepare_connect_*() functions.
In addition, pass the address of a variable that will hold the
authorization protocol to use. Move the assignment of that to the
connection's out_connect structure into prepare_write_connect().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Change prepare_connect_authorizer() so it returns a pointer (or
pointer-coded error).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Rather than passing a bunch of arguments to be filled in with the
content of the ceph_auth_handshake buffer now returned by the
get_authorizer method, just use the returned information in the
caller, and drop the unnecessary arguments.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Have the get_authorizer auth_client method return a ceph_auth
pointer rather than an integer, pointer-encoding any returned
error value. This is to pave the way for making use of the
returned value in an upcoming patch.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
In prepare_connect_authorizer(), a connection's get_authorizer
method is called but ignores its return value. This function can
return an error, so check for it and return it if that ever occurs.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Change prepare_connect_authorizer() so it returns without dropping
the connection mutex if the connection has no get_authorizer method.
Use the symbolic CEPH_AUTH_UNKNOWN instead of 0 when assigning
authorization protocols.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
prepare_write_connect() can return an error, but only one of its
callers checks for it. All the rest are in functions that already
return errors, so it should be fine to return the error if one
gets returned.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
prepare_write_connect() prepares a connect message, then sets
WRITE_PENDING on the connection. Then *after* this, it calls
prepare_connect_authorizer(), which updates the content of the
connection buffer already queued for sending. It's also possible it
will result in prepare_write_connect() returning -EAGAIN despite the
WRITE_PENDING big getting set.
Fix this by preparing the connect authorizer first, setting the
WRITE_PENDING bit only after that is done.
Partially addresses http://tracker.newdream.net/issues/2424
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
In all cases, the value passed as the msgr argument to
prepare_write_connect() is just con->msgr. Just get the msgr
value from the ceph connection and drop the unneeded argument.
The only msgr passed to prepare_write_banner() is also therefore
just the one from con->msgr, so change that function to drop the
msgr argument as well.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
prepare_write_connect() has an argument indicating whether a banner
should be sent out before sending out a connection message. It's
only ever set in one of its callers, so move the code that arranges
to send the banner into that caller and drop the "include_banner"
argument from prepare_write_connect().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reset a connection's kvec fields in the caller rather than in
prepare_write_connect(). This ends up repeating a few lines of
code but it's improving the separation between distinct operations
on the connection, which we can take advantage of later.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Move the kvec reset for a connection out of prepare_write_banner and
into its only caller.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Make the second argument to read_partial() be the ending input byte
position rather than the beginning offset it now represents. This
amounts to moving the addition "to + size" into the caller.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
read_partial() always increases whatever "to" value is supplied by
adding the requested size to it, and that's the only thing it does
with that pointed-to value.
Do that pointer advance in the caller (and then only when the
updated value will be subsequently used), and change the "to"
parameter to be an in-only and non-pointer value.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
There are two blocks of code in read_partial_message()--those that
read the header and footer of the message--that can be replaced by a
call to read_partial(). Do that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
In write_partial_msg_pages(), every case now does an identical call
to kmap(page). Instead, just call it once inside the CRC-computing
block where it's needed. Move the definition of kaddr inside that
block, and make it a (char *) to ensure portable pointer arithmetic.
We still don't kunmap() it until after the sendpage() call, in case
that also ends up needing to use the mapping.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
In write_partial_msg_pages() there is a local variable used to
track the starting offset within a bio segment to use. Its name,
"page_shift" defies the Linux convention of using that name for
log-base-2(page size).
Since it's only used in the bio case rename it "bio_offset". Use it
along with the page_pos field to compute the memory offset when
computing CRC's in that function. This makes the bio case match the
others more closely.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
There's not a lot of benefit to zero_page_address, which basically
holds a mapping of the zero page through the life of the messenger
module. Even with our own mapping, the sendpage interface where
it's used may need to kmap() it again. It's almost certain to
be in low memory anyway.
So stop treating the zero page specially in write_partial_msg_pages()
and just get rid of zero_page_address entirely.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
Make ceph_tcp_sendpage() be the only place kernel_sendpage() is
used, by using this helper in write_partial_msg_pages().
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
If a message queued for send gets revoked, zeroes are sent over the
wire instead of any unsent data. This is done by constructing a
message and passing it to kernel_sendmsg() via ceph_tcp_sendmsg().
Since we are already working with a page in this case we can use
the sendpage interface instead. Create a new ceph_tcp_sendpage()
helper that sets up flags to match the way ceph_tcp_sendmsg()
does now.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
CRC's are computed for all messages between ceph entities. The CRC
computation for the data portion of message can optionally be
disabled using the "nocrc" (common) ceph option. The default is
for CRC computation for the data portion to be enabled.
Unfortunately, the code that implements this feature interprets the
feature flag wrong, meaning that by default the CRC's have *not*
been computed (or checked) for the data portion of messages unless
the "nocrc" option was supplied.
Fix this, in write_partial_msg_pages() and read_partial_message().
Also change the flag variable in write_partial_msg_pages() to be
"no_datacrc" to match the usage elsewhere in the file.
This fixes http://tracker.newdream.net/issues/2064
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
Nothing too big here.
- define the size of the buffer used for consuming ignored
incoming data using a symbolic constant
- simplify the condition determining whether to unmap the page
in write_partial_msg_pages(): do it for crc but not if the
page is the zero page
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Make a small change in the code that counts down kvecs consumed by
a ceph_tcp_sendmsg() call. Same functionality, just blocked out
a little differently.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Move blocks of code out of loops in read_partial_message_section()
and read_partial_message(). They were only was getting called at
the end of the last iteration of the loop anyway.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Calculate CRC in a separate step from rearranging the byte order
of the result, to improve clarity and readability.
Use offsetof() to determine the number of bytes to include in the
CRC calculation.
In read_partial_message(), switch which value gets byte-swapped,
since the just-computed CRC is already likely to be in a register.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Change the name (and type) of a few CRC-related Boolean local
variables so they contain the word "do", to distingish their purpose
from variables used for holding an actual CRC value.
Note that in the process of doing this I identified a fairly serious
logic error in write_partial_msg_pages(): the value of "do_crc"
assigned appears to be the opposite of what it should be. No
attempt to fix this is made here; this change preserves the
erroneous behavior. The problem I found is documented here:
http://tracker.newdream.net/issues/2064
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
This gathers a number of very minor changes:
- use %hu when formatting the a socket address's address family
- null out the ceph_msgr_wq pointer after the queue has been
destroyed
- drop a needless cast in ceph_write_space()
- add a WARN() call in ceph_state_change() in the event an
unrecognized socket state is encountered
- rearrange the logic in ceph_con_get() and ceph_con_put() so
that:
- the reference counts are only atomically read once
- the values displayed via dout() calls are known to
be meaningful at the time they are formatted
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
There is no real need for ceph_tcp_connect() to return the socket
pointer it creates, since it already assigns it to con->sock, which
is visible to the caller. Instead, have it return an error code,
which tidies things up a bit.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Define a helper function to perform various cleanup operations. Use
it both in the exit routine and in the init routine in the event of
an error.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The messenger workqueue has no need to be public. So give it static
scope.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Encapsulate the operation of adding a new chunk of data to the next
open slot in a ceph_connection's out_kvec array. Also add a "reset"
operation to make subsequent add operations start at the beginning
of the array again.
Use these routines throughout, avoiding duplicate code and ensuring
all calls are handled consistently.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
One of the arguments to prepare_write_connect() indicates whether it
is being called immediately after a call to prepare_write_banner().
Move the prepare_write_banner() call inside prepare_write_connect(),
and reinterpret (and rename) the "after_banner" argument so it
indicates that prepare_write_connect() should *make* the call
rather than should know it has already been made.
This was split out from the next patch to highlight this change in
logic.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
This fixes some spots where a type cast to (void *) was used as
as a universal type hiding mechanism. Instead, properly cast the
type to the intended target type.
Signed-off-by: Alex Elder <elder@newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
This eliminates type casts in some places where they are not
required.
Signed-off-by: Alex Elder <elder@newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
A spinlock is used to protect a value used for selecting an array
index for a string used for formatting a socket address for human
consumption. The index is reset to 0 if it ever reaches the maximum
index value.
Instead, use an ever-increasing atomic variable as a sequence
number, and compute the array index by masking off all but the
sequence number's lowest bits. Make the number of entries in the
array a power of two to allow the use of such a mask (to avoid jumps
in the index value when the sequence number wraps).
The length of these strings is somewhat arbitrarily set at 60 bytes.
The worst-case length of a string produced is 54 bytes, for an IPv6
address that can't be shortened, e.g.:
[1234:5678:9abc:def0:1111:2222:123.234.210.100]:32767
Change it so we arbitrarily use 64 bytes instead; if nothing else
it will make the array of these line up better in hex dumps.
Rename a few things to reinforce the distinction between the number
of strings in the array and the length of individual strings.
Signed-off-by: Alex Elder <elder@newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
Rearrange ceph_tcp_connect() a bit, making use of "else" rather than
re-testing a value with consecutive "if" statements. Don't record a
connection's socket pointer unless the connect operation is
successful.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Each messenger allocates a page to be used when writing zeroes
out in the event of error or other abnormal condition. Instead,
use the kernel ZERO_PAGE() for that purpose.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Alex Elder
Alex Elder