linux_dsm_epyc7002/net/ceph
Alex Elder fe38a2b67b libceph: start defining message data cursor
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>
2013-05-01 21:16:56 -07:00
..
crush crush: avoid recursion if we have already collided 2013-01-17 12:42:39 -06:00
armor.c libceph: Fix base64-decoding when input ends in newline. 2011-03-15 09:14:02 -07:00
auth_none.c ceph: messenger: reduce args to create_authorizer 2012-05-17 08:18:12 -05:00
auth_none.h ceph: factor out libceph from Ceph file system 2010-10-20 15:37:28 -07:00
auth_x_protocol.h ceph: factor out libceph from Ceph file system 2010-10-20 15:37:28 -07:00
auth_x.c ceph: messenger: reduce args to create_authorizer 2012-05-17 08:18:12 -05:00
auth_x.h net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
auth.c ceph: Move secret key parsing earlier. 2011-03-29 12:11:16 -07:00
buffer.c net: allow GFP_HIGHMEM in __vmalloc() 2010-11-21 10:04:04 -08:00
ceph_common.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2013-02-28 17:43:09 -08:00
ceph_fs.c ceph: fix file mode calculation 2011-07-19 11:25:04 -07:00
ceph_hash.c net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
ceph_strings.c libceph: update ceph_osd_op_name() 2013-02-18 12:20:18 -06:00
crypto.c libceph: eliminate sparse warnings 2013-02-25 15:37:18 -06:00
crypto.h libceph: fix crypto key null deref, memory leak 2012-08-02 09:19:20 -07:00
debugfs.c libceph: update osd request/reply encoding 2013-02-26 15:02:50 -08:00
Kconfig net/ceph: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:33 -08:00
Makefile Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-12-08 13:47:38 -08:00
messenger.c libceph: start defining message data cursor 2013-05-01 21:16:56 -07:00
mon_client.c libceph: eliminate sparse warnings 2013-02-25 15:37:18 -06:00
msgpool.c libceph: initialize msgpool message types 2012-07-30 09:29:50 -07:00
osd_client.c libceph: set response data fields earlier 2013-05-01 21:16:43 -07:00
osdmap.c libceph: rename ceph_calc_object_layout() 2013-05-01 21:16:17 -07:00
pagelist.c ceph: use list_move_tail instead of list_del/list_add_tail 2012-10-01 14:30:49 -05:00
pagevec.c libceph: drop return value from page vector copy routines 2013-02-19 19:14:05 -06:00