diff options
| author | Jeff Darcy <jdarcy@redhat.com> | 2015-03-10 20:14:47 -0400 |
|---|---|---|
| committer | Vijay Bellur <vbellur@redhat.com> | 2015-03-17 07:02:15 -0700 |
| commit | 0d2bed70faed3c63f25ed9269dc55562973ef9b7 (patch) | |
| tree | fee1995e88b7ae19d1cb27cf437ab76583d111e6 /libglusterfs/src/xlator.h | |
| parent | 6b3704990257643da54100d8581856a7d2c72f86 (diff) | |
every/where: add GF_FOP_IPC for inter-translator communication
Several features - e.g. encryption, erasure codes, or NSR - involve
multiple cooperating translators which sometimes need a "private" means
of communication amongst themselves. Historically we've used virtual or
synthetic xattrs, but that's not very elegant and clutters up the
getxattr/setxattr path which must also handle real xattr requests. This
new fop should address that.
The only argument is an int32_t "op" which should be recognized by the
target translator. It is recommended that translators using these
feature follow some convention regarding the ops that they define, to
avoid conflicts. Using a hash of the target translator's type string as
a base for a series of ops would probably be a good start. Any other
information can be passed in both directions using xdata.
The default behavior for this fop, as with any other, is to pass through
to FIRST_CHILD. That makes use of this fop "transparent" to other
translators that were written before it existed, but it also means that
it only really works with pass-through translators. If a routing
translator (such as DHT) or a fan-out translator (such as AFR) is
involved, the IPC might not reach its intended destination unless those
translators are modified to forward IPC fops along all paths.
If an IPC gets all the way to storage/posix it is considered an error,
much like an uncaught exception. We don't actually *do* anything in
that case, but we do log it send back an EOPNOTSUPP error. This makes
the "unrecognized opcode" condition distinguishable from the "no IPC
support" condition (which would yield an RPC error instead) so clients
can probe for the presence of a handler for their own favorite opcode
and either use that or use old-school xattrs depending on the result.
BUG: 1158628
Signed-off-by: Venky Shankar <vshankar@redhat.com>
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
Change-Id: I84af1b17babe5b30ec03ecf027ae37d09b873968
Reviewed-on: http://review.gluster.org/8812
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Diffstat (limited to 'libglusterfs/src/xlator.h')
| -rw-r--r-- | libglusterfs/src/xlator.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/libglusterfs/src/xlator.h b/libglusterfs/src/xlator.h index 8e52bbb3010..e953ec04372 100644 --- a/libglusterfs/src/xlator.h +++ b/libglusterfs/src/xlator.h @@ -443,6 +443,10 @@ typedef int32_t (*fop_zerofill_cbk_t) (call_frame_t *frame, struct iatt *preop_stbuf, struct iatt *postop_stbuf, dict_t *xdata); +typedef int32_t (*fop_ipc_cbk_t) (call_frame_t *frame, void *cookie, + xlator_t *this, int32_t op_ret, + int32_t op_errno, dict_t *xdata); + typedef int32_t (*fop_lookup_t) (call_frame_t *frame, xlator_t *this, loc_t *loc, @@ -674,6 +678,7 @@ typedef int32_t (*fop_discard_t) (call_frame_t *frame, off_t offset, size_t len, dict_t *xdata); + typedef int32_t (*fop_zerofill_t) (call_frame_t *frame, xlator_t *this, fd_t *fd, @@ -681,6 +686,9 @@ typedef int32_t (*fop_zerofill_t) (call_frame_t *frame, off_t len, dict_t *xdata); +typedef int32_t (*fop_ipc_t) (call_frame_t *frame, xlator_t *this, int32_t op, + dict_t *xdata); + struct xlator_fops { fop_lookup_t lookup; fop_stat_t stat; @@ -727,6 +735,7 @@ struct xlator_fops { fop_fallocate_t fallocate; fop_discard_t discard; fop_zerofill_t zerofill; + fop_ipc_t ipc; /* these entries are used for a typechecking hack in STACK_WIND _only_ */ fop_lookup_cbk_t lookup_cbk; @@ -774,6 +783,7 @@ struct xlator_fops { fop_fallocate_cbk_t fallocate_cbk; fop_discard_cbk_t discard_cbk; fop_zerofill_cbk_t zerofill_cbk; + fop_ipc_cbk_t ipc_cbk; }; typedef int32_t (*cbk_forget_t) (xlator_t *this, |