glusterfs.git/api/src/glfs.h, branch v3.5.6

NetBSD build fixes for release-3.5

2014-06-08T09:18:13+00:00

1) Make sure __THROW is definedThis is a backport of I6e7cb1eb59b84988e155e9a8b696e842b7ff8f7f

2) include  before  so that XDR is defined
This was fixed in master within I20193d3f8904388e47344e523b3787dbeab044acbut weonly pull up

3) NetBSD's gettext is in libintl, hence search it at configure time
This is a backport of I651a74fe49c3f087fe135dab3453fd5b18b4268a

4) include  to have WEXITSTATUS defined
This problem does not exist in master as WEXITSTATUS is not used

5) Do not define popcountl() on NetBSD as it is in 
This is a backport of I4428a88b1e0d7c5f6740022861ffe230dbbd84bd

BUG: 764655
Change-Id: Ieea5a2a627e2b7930525d6c525f1602073574a97
Signed-off-by: Emmanuel Dreyfus 
Reviewed-on: http://review.gluster.org/7925
Reviewed-by: Kaleb KEITHLEY 
Reviewed-by: Niels de Vos 
Tested-by: Gluster Build System

libgfapi: Added support to fetch volume info from glusterd and store in glfs object.

2014-05-12T15:14:52+00:00

Defined new APIs in the libgfapi module, given a glfs object,
 * to send handshake RPC call to glusterd process to fetch UUID of the volume
 * store it in the glusterfs_context linked to the glfs object.
 * to parse UUID from its cannonical string format into 16-byte array
   before sending it to the libgfapi users.

Defined a RPC call in glusterd which can be used to query volume related
info by other processes using 'clnt_handshake_procs'.

Note - Currently this RPC call to glusterd process is used only to fetch UUID.
But it can be extended to get other volume related structures as well.

In addition to the above, defined a new variable to keep track of such handshake
RPCs still in progress to make sure all the corresponding RPC callbacks have been
processed before libgfapi returns the glfs object initialized.

Also bumping up the GFAPI current version number since there is a new API
"glfs_get_volume_id" defined and exposed by libgfapi as part of these changes.

Cherry picked from commit 5adb10b9ac1c634334f29732e062b12d747ae8c5:
> Change-Id: I303f76d7177d32d25bdb301b1dbcf5cd73f42807
> BUG: 1095775
> Signed-off-by: Soumya Koduri 
> Reviewed-on: http://review.gluster.org/7218
> Reviewed-by: Anand Avati 
> Reviewed-by: Harshavardhana 
> Tested-by: Gluster Build System 
> Reviewed-by: Vijay Bellur 

This change differs a little from the patch in the master branch:
- libgfapi in 3.5 does not have glfs_get_volfile(), so there were some
  merge conflicts resolved,
- libgfapi in 3.5 is not versioned, the configure.ac changes related to
  the versioning have been skipped,
- in the master branch only the XDR .x files are available, release-3.5
  requires a manual re-generation of the relates .h and .c files.

Change-Id: I52c32d0e69a52a7f4285f74164bca6fd83c4f3b3
BUG: 1095775
Signed-off-by: Soumya Koduri 
Reviewed-on: http://review.gluster.org/7741
Reviewed-by: Niels de Vos 
Tested-by: Niels de Vos

gfapi: glfs_set_volfile_server() now entertains multiple calls

2014-05-10T02:06:36+00:00

Backport from - http://review.gluster.org/7317

Previous API:

glfs_set_volfile_server (..., const char *host, ...) - single call

New API's:

glfs_set_volfile_server (..., const char *host1, ...)
glfs_set_volfile_server (..., const char *host2, ...)

Multiple calls to this function with different volfile servers,
port or transport-type would create a list of volfile servers
which would be polled during `volfile_fetch_attempts()`

glfs_unset_volfile_server (..., const char *host, ...) to remove
a server from the list (this is provided for future usage)

>> Change-Id: I313efbd3efbd0214e2a71465f33195788df406cc
>> BUG: 986429
>> Signed-off-by: Harshavardhana 
>> Reviewed-on: http://review.gluster.org/7317
>> Tested-by: Gluster Build System 
>> Reviewed-by: Niels de Vos 
>> Reviewed-by: Anand Avati 

Change-Id: If0020f6b8775bdbe987563247c83d59a2d3744ad
BUG: 986429
Signed-off-by: Harshavardhana 
Reviewed-on: http://review.gluster.org/7384
Tested-by: Gluster Build System 
Reviewed-by: Niels de Vos

zerofill: Change the type of len argument of glfs_zerofill() to off_t

2013-11-15T07:29:48+00:00

glfs_zerofill() can be potentially called to zero-out entire file and
hence allow for bigger value of length parameter.

Change-Id: I75f1d11af298915049a3f3a7cb3890a2d72fca63
BUG: 1028673
Signed-off-by: Bharata B Rao 
Reviewed-on: http://review.gluster.org/6266
Tested-by: Gluster Build System 
Reviewed-by: M. Mohan Kumar 
Tested-by: M. Mohan Kumar 
Reviewed-by: Anand Avati

gfapi: introduce glfs_readdir() and glfs_readdirplus() APIs

2013-11-13T18:48:18+00:00

Change-Id: I6b233bf647585675f233898351bf593f251716cc
BUG: 839950
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/6201
Tested-by: Gluster Build System 
Reviewed-by: Raghavendra Talur

glusterfs: zerofill support

2013-11-11T05:25:49+00:00

Add support for a new ZEROFILL fop. Zerofill writes zeroes to a file in
the specified range. This fop will be useful when a whole file needs to
be initialized with zero (could be useful for zero filled VM disk image
provisioning or  during scrubbing of VM disk images).

Client/application can issue this FOP for zeroing out. Gluster server
will zero out required range of bytes ie server offloaded zeroing. In
the absence of this fop,  client/application has to repetitively issue
write (zero) fop to the server, which is very inefficient method because
of the overheads involved in RPC calls  and acknowledgements.

WRITESAME is a  SCSI T10 command that takes a block of data as input and
writes the same data to other blocks and this write is handled
completely within the storage and hence is known as offload . Linux ,now
has support for SCSI WRITESAME command which is exposed to the user in
the form of BLKZEROOUT ioctl.  BD Xlator can exploit BLKZEROOUT ioctl to
implement this fop. Thus zeroing out operations can be completely
offloaded to the storage device , making it highly efficient.

The fop takes two arguments offset and size. It zeroes out 'size' number
of bytes in an opened file starting from 'offset' position.

This patch adds zerofill support to the following areas:
	- libglusterfs
	- io-stats
	- performance/md-cache,open-behind
	- quota
	- cluster/afr,dht,stripe
	- rpc/xdr
	- protocol/client,server
	- io-threads
	- marker
	- storage/posix
	- libgfapi

Client applications can exloit this fop by using glfs_zerofill introduced in
libgfapi.FUSE support to this fop has not been added as there is no system call
for this fop.

Changes from previous version 3:
* Removed redundant memory failure log messages

Changes from previous version 2:
* Rebased and fixed build error

Changes from previous version 1:
* Rebased for latest master

TODO :
     * Add zerofill support to trace xlator
     * Expose zerofill capability as part of gluster volume info

Here is a performance comparison of server offloaded zeofill vs zeroing
out using repeated writes.

[root@llmvm02 remote]# time ./offloaded aakash-test log 20

real	3m34.155s
user	0m0.018s
sys	0m0.040s
[root@llmvm02 remote]# time ./manually aakash-test log 20

real	4m23.043s
user	0m2.197s
sys	0m14.457s
[root@llmvm02 remote]# time ./offloaded aakash-test log 25;

real	4m28.363s
user	0m0.021s
sys	0m0.025s
[root@llmvm02 remote]# time ./manually aakash-test log 25

real	5m34.278s
user	0m2.957s
sys	0m18.808s

The argument log is a file which we want to set for logging purpose and
the third argument is size in GB .

As we can see there is a performance improvement of around 20% with this
fop.

Change-Id: I081159f5f7edde0ddb78169fb4c21c776ec91a18
BUG: 1028673
Signed-off-by: Aakash Lal Das 
Signed-off-by: M. Mohan Kumar 
Reviewed-on: http://review.gluster.org/5327
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

gfapi: object handle based API extensions

2013-10-11T19:16:46+00:00

There is an ongoing effort to integrate NFS Ganesha (
https://github.com/nfs-ganesha/nfs-ganesha/wiki ) with GlusterFS as one of
the file system back ends.

Towards this we need extensions to gfapi that can handle object based
operations. Meaning, instead of using full paths or relative paths from
cwd, it is required that we can work with APIs, like the *at POSIX
variants, to be able to create, lookup, open etc. files and directories.
Hence the objects are the files or directories themselves and we give out
handles to these objects that can be used for further operations.

This code drop is an initial implementation of the proposed APIs.

The new APIs are implemented as glfs_h_XXX variants in the file
glfs-handleops.c to mirror glfs-fops.c style. The code leverages holding
onto inode references and doling these out as opaque/cookie type objects to
the callers, to enable them to be used as handles in other operations.

An fd based approach was considered, but due to the extra footprint that
the fd structure and its counterparts would incur, this was dropped to take
the approach of holding inode references themselves.

Tested by extending glfsxmp.c to invoke and exercise the added APIs, and
further tested with a reference integration of the same as an FSAL with NFS
Ganesha.

Change-Id: I23629c99e905b54070fa2e6565147812e5f3fa5d
BUG: 1016000
Signed-off-by: R.Shyamsundar 
Reviewed-on: http://review.gluster.org/5936
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

logging: Expose set_log_file_path() in libglusterfs.

2013-09-24T19:00:54+00:00

This patch also changes the behavior of glfs_set_logging().
If logfile argument is not provided to glfs_set_logging(),
libgfapi uses set_log_file_path() to create a logfile.

Change-Id: I49ec66c7f16f5604ff2f7cf7b365b08a05b5460d
BUG: 764890
Signed-off-by: Vijay Bellur 
Reviewed-on: http://review.gluster.org/5910
Reviewed-by: Anand Avati 
Tested-by: Anand Avati

gfapi: implement a minimial glfs_fini()

2013-09-17T18:42:12+00:00

At the very least, we should PARENT_DOWN on the currently active
graph and disconnect ourselves from glusterd.

Further cleanups underway.

Change-Id: I9276686a84b0975b5ce272b4cbec1b80920d5c5c
BUG: 1004519
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/5788
Tested-by: Gluster Build System 
Reviewed-by: Raghavendra Bhat 
Reviewed-by: Amar Tumballi

gfapi: Add description of glfs_io_cbk function as a comment

2013-08-23T10:37:23+00:00

No code change, just add a comment describing the callback function
type.

Change-Id: I3a5c5b3d3fe042b4f535963dd477806832c15704
BUG: 839950
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/5696
Reviewed-by: Vijay Bellur 
Tested-by: Vijay Bellur