glusterfs.git/xlators/protocol/client/src/client.h, branch v3.3.0qa23

rpc/clnt: handle PARENT_DOWN event appropriately

2012-02-21T09:42:42+00:00

Change-Id: I4644e944bad4d240d16de47786b9fa277333dba4
BUG: 767862
Signed-off-by: Raghavendra G 
Signed-off-by: Amar Tumballi 
Reviewed-on: http://review.gluster.com/2735
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

protocol/client,server: fcntl lock self healing.

2012-02-20T12:45:31+00:00

Currently(with out this patch), on a disconnect the server cleans up
the transport which inturn closes the fd's and releases the locks acquired on
those fd's by that client. On a reconnect, client just reopens the fd's but
doesn't reacquire the locks. The application that had previously acquired
the locks still is under the assumption that it is the owner of those locks
which might have been granted to other clients(if they request) by the server
leading to data corruption.

This patch allows the client to reacquire the fcntl locks (held on the fd's)
during client-server handshake.

* The server identifies the client via process-uuid-xl (which is a combination
  of uuid and client-protocol name, it is assumed to be unique) and lk-version
  number.

* The client maintains a list of process-uuid-xl, lk-version pair for each
  accepted connection. On a connect, the server traverses the list for a
  matching pair, if a matching pair is not found the the server returns
  lk-version with value 0, else it returns the lk-version it has in store.

* On a disconnect, the server and client enter grace period, and on the
  completion of the grace period, the client bumps up its lk-version number
  (which means, it will reacquire the locks the next time) and the server will
  distroy the connection. If reconnection happens within the grace period, the
  server will find the matching (process-uuid-xl, lk-version) pair in its list
  which guarantees that the fd's and there corresponding locks are still valid
  for this client.

Configurable options:
  To set grace-timeout, the following options are
    option server.grace-timeout value
    option client.grace-timeout value

  To enable or disable the lk-heal,
    option lk-heal [on|off]

gluster volume set command can be used to configurable options
Change-Id: Id677ef1087b300d649f278b8b2aa0d94eae85ed2
BUG: 795386
Signed-off-by: Mohammed Junaid 
Reviewed-on: http://review.gluster.com/2766
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

protocol/client: if the remote_fd is -1, then unwind instead of sending the call to server

2012-01-25T16:08:38+00:00

For calls with remote_fd set to -1, client xlator is sending the call to the
server which results in server not resolving it and thus fd being NULL. Locks
xlator when tries to get the inode context using the fd it segfaults. To avoid
it unwind the call in the client xlator if the remote_fd is -1.

Change-Id: Ic34a49fdf1012dd371f4b194703c0be74f29bda2
BUG: 784187
Signed-off-by: Raghavendra Bhat 
Reviewed-on: http://review.gluster.com/2684
Tested-by: Gluster Build System 
Reviewed-by: Jeff Darcy 
Reviewed-by: Krishnan Parthasarathi 
Reviewed-by: Anand Avati

core: get xattrs also as part of readdirp

2012-01-25T10:03:44+00:00

readdirp_req() call sends a dict_t * as an argument, which
contains all the xattr keys for which the entries got in
readdirp_rsp() are having xattr value filled dictionary.

Change-Id: I8b7e1290740ea3e884e67d19156ce849227167c0
Signed-off-by: Amar Tumballi 
BUG: 765785
Reviewed-on: http://review.gluster.com/771
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

core: change lk-owner as a 1k buffer

2012-01-25T04:14:17+00:00

so, NLM can send the lk-owner field directly to the locks translators,
while doing the same effort, also enabled sending maximum of 500 aux gid
over protocol.

Change-Id: I87c2514392748416f7ffe21d5154faad2e413969
Signed-off-by: Amar Tumballi 
BUG: 767229
Reviewed-on: http://review.gluster.com/779
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

core: GFID filehandle based backend and anonymous FDs

2012-01-20T13:03:42+00:00

1. What
--------
This change introduces an infrastructure change in the filesystem
which lets filesystem operation address objects (inodes) just by its
GFID. Thus far GFID has been a unique identifier of a user-visible
inode. But in terms of addressability the only mechanism thus far has
been the backend filesystem path, which could be derived from the
GFID only if it was cached in the inode table along with the entire set
of dentry ancestry leading up to the root.

This change essentially decouples addressability from the namespace. It
is no more necessary to be aware of the parent directory to address a
file or directory.

2. Why
-------
The biggest use case for such a feature is NFS for generating
persistent filehandles. So far the technique for generating filehandles
in NFS has been to encode path components so that the appropriate
inode_t can be repopulated into the inode table by means of a recursive
lookup of each component top-down.

Another use case is the ability to perform more intelligent self-healing
and rebalancing of inodes with hardlinks and also to detect renames.

A derived feature from GFID filehandles is anonymous FDs. An anonymous FD
is an internal USABLE "fd_t" which does not map to a user opened file
descriptor or to an internal ->open()'d fd. The ability to address a file
by the GFID eliminates the need to have a persistent ->open()'d fd for the
purpose of avoiding the namespace. This improves NFS read/write performance
significantly eliminating open/close calls and also fixes some of today's
limitations (like keeping an FD open longer than necessary resulting
in disk space leakage)

3. How
-------

At each storage/posix translator level, every file is hardlinked inside
a hidden .glusterfs directory (under the top level export) with the name
as the ascii-encoded standard UUID format string. For reasons of performance
and scalability there is a two-tier classification of those hardlinks
under directories with the initial parts of the UUID string as the directory
names.

For directories (which cannot be hardlinked), the approach is to use a symlink
which dereferences the parent GFID path along with basename of the directory.
The parent GFID dereference will in turn be a dereference of the grandparent
with the parent's basename, and so on recursively up to the root export.

4. Development
---------------

4a. To leverage the ability to address an inode by its GFID, the technique is
to perform a "nameless lookup". This means, to populate a loc_t structure as:

loc_t {
   pargfid: NULL
   parent: NULL
   name: NULL
   path: NULL
   gfid: GFID to be looked up [out parameter]
   inode: inode_new () result [in parameter]
}

and performing such lookup will return in its callback an inode_t
populated with the right contexts and a struct iatt which can be
used to perform an inode_link () on the inode (without a parent and
basename). The inode will now be hashed and linked in the inode table
and findable via inode_find().

A fundamental change moving forward is that the primary fields in a
loc_t structure are now going to be (pargfid, name) and (gfid) depending
on the kind of FOP. So far path had been the primary field for operations.
The remaining fields only serve as hints/helpers.

4b. If read/write is to be performed on an inode_t, the approach so far
has been to: fd_create(), STACK_WIND(open, fd), fd_bind (in callback) and
then perform STACK_WIND(read, fd) etc. With anonymous fds now you can do
fd_anonymous (inode), STACK_WIND (read, fd). This results in great boost
in performance in the inbuilt NFS server.

5. Misc
-------
The inode_ctx_put[2] has been renamed to inode_ctx_set[2] to be consistent
with the rest of the codebase.

Change-Id: Ie4629edf6bd32a595f4d7f01e90c0a01f16fb12f
BUG: 781318
Reviewed-on: http://review.gluster.com/669
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

protocol/client: avoid code duplication in fd based operations

2011-09-12T06:24:38+00:00

Change-Id: I012f78bac8ba82333628c59ef51d5e5f43d05ac7
BUG: 3158
Reviewed-on: http://review.gluster.com/329
Tested-by: Gluster Build System 
Reviewed-by: Amar Tumballi 
Reviewed-by: Vijay Bellur

modify to the way we used XDR definitions files (.x files)

2011-09-07T17:48:52+00:00

Earlier:
step 1: copy the existing .x files to /tmp
step 2: generate '.[ch]' files using 'rpcgen .x'
step 3: check diff with the to the existing files, add only your part
        of changes back to the original file. (ignore other changes).
step 4: there is another file to write wrapper functions to convert
        structures to/from XDR buffers, update it with your new structure.
step 5: use these wrapper functions in the newly written procedures.
step 6: commit :-|

Now:
step 1: update (mostly adding only) the .x file
step 2: run '/extras/generate-xdr-files.sh .x' command
step 3: implement rpc procedure to handle the request/response.
step 4: commit :-)

Change-Id: I219f9159fc980438c86e847c6b030be96e595ea2
BUG: 3488
Reviewed-on: http://review.gluster.com/341
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

glusterfs protocol: bring in variable sized iobuf support

2011-09-07T17:48:29+00:00

is a step towards reducing glusterfs memory footprint. should also
help a bit in overall performance.

Change-Id: I074d5813602b2c960d59562e792b3dc6e43d2f42
BUG: 3475
Reviewed-on: http://review.gluster.com/322
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

Change Copyright current year

2011-08-10T17:57:19+00:00

Change-Id: I2d10f2be44f518f496427f257988f1858e888084
BUG: 3348
Reviewed-on: http://review.gluster.com/200
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati