Commit Graph

119 Commits

Author SHA1 Message Date
Alex Elder
8d63e318c4 libceph: isolate kmap() call in write_partial_msg_pages()
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>
2012-03-22 10:47:52 -05:00
Alex Elder
9bd1966344 libceph: rename "page_shift" variable to something sensible
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>
2012-03-22 10:47:52 -05:00
Alex Elder
0cdf9e6018 libceph: get rid of zero_page_address
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>
2012-03-22 10:47:52 -05:00
Alex Elder
e36b13cceb libceph: only call kernel_sendpage() via helper
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>
2012-03-22 10:47:52 -05:00
Alex Elder
31739139f3 libceph: use kernel_sendpage() for sending zeroes
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>
2012-03-22 10:47:51 -05:00
Alex Elder
37675b0f42 libceph: fix inverted crc option logic
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>
2012-03-22 10:47:51 -05:00
Alex Elder
84495f4961 libceph: some simple changes
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>
2012-03-22 10:47:51 -05:00
Alex Elder
f42299e6c3 libceph: small refactor in write_partial_kvec()
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>
2012-03-22 10:47:51 -05:00
Alex Elder
fe3ad593e2 libceph: do crc calculations outside loop
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>
2012-03-22 10:47:51 -05:00
Alex Elder
a9a0c51af4 libceph: separate CRC calculation from byte swapping
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>
2012-03-22 10:47:51 -05:00
Alex Elder
bca064d236 libceph: use "do" in CRC-related Boolean variables
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>
2012-03-22 10:47:51 -05:00
Alex Elder
cffaba15cd ceph: ensure Boolean options support both senses
Many ceph-related Boolean options offer the ability to both enable
and disable a feature.  For all those that don't offer this, add
a new option so that they do.

Note that ceph_show_options()--which reports mount options currently
in effect--only reports the option if it is different from the
default value.

Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
2012-03-22 10:47:51 -05:00
Alex Elder
d3002b974c libceph: a few small changes
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>
2012-03-22 10:47:51 -05:00
Alex Elder
41617d0c9c libceph: make ceph_tcp_connect() return int
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>
2012-03-22 10:47:51 -05:00
Alex Elder
6173d1f02f libceph: encapsulate some messenger cleanup code
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>
2012-03-22 10:47:50 -05:00
Alex Elder
e0f43c9419 libceph: make ceph_msgr_wq private
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>
2012-03-22 10:47:50 -05:00
Alex Elder
859eb79948 libceph: encapsulate connection kvec operations
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>
2012-03-22 10:47:50 -05:00
Alex Elder
963be4d770 libceph: move prepare_write_banner()
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>
2012-03-22 10:47:50 -05:00
Alex Elder
ee57741c52 rbd: make ceph_parse_options() return a pointer
ceph_parse_options() takes the address of a pointer as an argument
and uses it to return the address of an allocated structure if
successful.  With this interface is not evident at call sites that
the pointer is always initialized.  Change the interface to return
the address instead (or a pointer-coded error code) to make the
validity of the returned pointer obvious.

Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
2012-03-22 10:47:47 -05:00
Alex Elder
99f0f3b2c4 ceph: eliminate some abusive casts
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>
2012-03-22 10:47:45 -05:00
Alex Elder
bd40614512 ceph: eliminate some needless casts
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>
2012-03-22 10:47:45 -05:00
Alex Elder
f64a93172b ceph: kill addr_str_lock spinlock; use atomic instead
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>
2012-03-22 10:47:45 -05:00
Alex Elder
a5bc3129a2 ceph: make use of "else" where appropriate
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>
2012-03-22 10:47:45 -05:00
Alex Elder
5766651971 ceph: use a shared zero page rather than one per messenger
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>
2012-03-22 10:47:45 -05:00
Xi Wang
6448669777 libceph: fix overflow check in crush_decode()
The existing overflow check (n > ULONG_MAX / b) didn't work, because
n = ULONG_MAX / b would both bypass the check and still overflow the
allocation size a + n * b.

The correct check should be (n > (ULONG_MAX - a) / b).

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
2012-03-22 10:47:45 -05:00