glusterfs.git/api/src/glfs-internal.h, branch v3.7.16

gfapi: redesign the public interface for upcall consumers

2016-10-03T12:20:43+00:00

The glfs_callback_arg and glfs_callback_inode_arg were allocated by
gfapi, and expected to be free()'d by the application. However it is not
reasonable to expect that applications use the same memory allocator to
as the compiled libgfapi.so. For instance, it is possible that gfapi
uses glibc malloc/free, and an application like NFS-Ganesha the versions
from jemalloc. Mismatching of the malloc() and free() functions causes
segmentation faults at best.

In order to prevent problems like this in the future, the API for
applications that consume upcalls has been remodeled. Any of the
structures that gfapi allocates, should be free'd with glfs_free(). The
members of the structures can not be accessed directly anymore, each
has its own function to access now.

Correcting the naming of the functions, structures and constants is a
continuation of commit 2775dc64101ed37c8d9809bf9852dbf0746ee2b6. These
new improvements not only have correct prefixes for the functions and
structures, the naming also reflects more to the upcall framework and
does not use "callback" anymore.

Cherry picked from commit 4721188a154acd9a0a4c096d8d73e97f3bf1b2a9:
> Change-Id: I2b8bd5a0a82036d2abea1a217f5e5975a1d4fe93
> BUG: 1344714
> Signed-off-by: Niels de Vos 
> Reviewed-on: http://review.gluster.org/14701
> Smoke: Gluster Build System 
> NetBSD-regression: NetBSD Build System 
> CentOS-regression: Gluster Build System 
> Reviewed-by: Kaleb KEITHLEY 
> Reviewed-by: soumya k 
> Reviewed-by: jiffin tony Thottan 

Once difference with the version of this change in other branches is
that leases are not included in glusterfs-3.7. Hence there is a little
change that drops the handling of GF_UPCALL_RECALL_LEASE.

In addition, this backport contains commit 2775dc6410:
> libgfapi/upcall : prepend "glfs_" to callback_arg, callback_inode_arg
> Reviewed-on: http://review.gluster.org/14702

Change-Id: I2b8bd5a0a82036d2abea1a217f5e5975a1d4fe93
BUG: 1347715
Signed-off-by: Niels de Vos 
Reviewed-on: http://review.gluster.org/15602
NetBSD-regression: NetBSD Build System 
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Kaushal M

gfapi: do not cache upcalls if the application is not interested

2016-09-05T09:09:01+00:00

When the volume option 'features.cache-invalidation' is enabled, upcall
events are sent from the brick process to the client. Even if the client
is not interested in upcall events itself, md-cache or other xlators may
benefit from them.

By adding a new 'cache_upcalls' boolean in the 'struct glfs', we can
enable the caching of upcalls when the application called
glfs_h_poll_upcall(). NFS-Ganesha sets up a thread for handling upcalls
in the initialization phase, and calls glfs_h_poll_upcall() before any
NFS-client accesses the NFS-export.

In the future there will be a more flexible registration API for
enabling certain kind of upcall events. Until that is available, this
should work just fine.

Verificatio of this change is not trivial within our current regression
test framework. The bug report contains a description on how to reliably
reproduce the problem with the glusterfs-coreutils.

Cherry picked from commit 218c9b033fa44eacbc27d87491abd830548b362e:
> Change-Id: I818595c92db50e6e48f7bfe287ee05103a4a30a2
> BUG: 1368842
> Signed-off-by: Niels de Vos 
> Reviewed-on: http://review.gluster.org/15191
> Smoke: Gluster Build System 
> Reviewed-by: Poornima G 
> NetBSD-regression: NetBSD Build System 
> CentOS-regression: Gluster Build System 
> Reviewed-by: soumya k 
> Reviewed-by: Kaleb KEITHLEY 

Change-Id: I818595c92db50e6e48f7bfe287ee05103a4a30a2
BUG: 1368843
Signed-off-by: Niels de Vos 
Reviewed-on: http://review.gluster.org/15347
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Poornima G 
Reviewed-by: soumya k

gfapi: Fix IO error caused when there is consecutive graph switches

2016-08-25T04:42:50+00:00

Backport of http://review.gluster.org/#/c/14722/

This is part 2 of the fix, the part 1 can be found at:
http://review.gluster.org/#/c/14656/

Problem:
=======
Consider a race between, __glfs_active_subvol() and graph_setup().
Lets say @TIME T1:
fs->active_subvol = A
fs->next_subvol = B
__glfs_active_subvol()                //under lock fs->mutex
{
  ....
  new_subvol = fs->next_subvol       //which is B
  ....                               //Start migration from A to B
  __glfs_first_lookup(){
     ....
     unlock fs->mutex                //@TIME T2
     network fop
     lock fs->mutex
     ....
  }
  ....                                //migration continue on B
  fs->active_subvol = fs->next_subvol //which is C (explained below)
  ....
}

@Time T2, lets say in another thread, graph_setup() is called with C,
note that at T2, fs->mutex is unlocked.

graph_stup(C...)
{
  lock fs->mutex
  ....
  if (fs->next_subvol)                // which is B
      destroy subvol (fs->next_subvol)
  ....
  fs->next_subvol = C
  ....
  unlock fs->mutex
}

Thus at the end of this,
fs->old_subvol = A;
fs->active_subvol = C;
fs->next_subvol = NULL;
which is wrong, as B completed migration, but was destroyed by
graph_setup, and C never was migrated.

Solution:
=========
Any new graph can be in one of the 2 states:
- Picked for migration, migration in progress (fs->mip_subvol)
- Not picked so far for migration (fs->next_subvol)
graph_setup() updates fs->next_subvol only, __glfs_active_subvol()
moves fs->next_subvol to fs->mip_subvol and fs->next_subvol = NULL
atomically, and then once the migration is complete, make that the
fs->active_subvol

> Reviewed-on: http://review.gluster.org/14722
> Smoke: Gluster Build System 
> CentOS-regression: Gluster Build System 
> NetBSD-regression: NetBSD Build System 
> Reviewed-by: Raghavendra Talur 
> Reviewed-by: Rajesh Joseph 
> Reviewed-by: Niels de Vos 

BUG: 1367294
Change-Id: Ib6ff0565105c5eedb912a43da4017cd413243612
Signed-off-by: Poornima G 
Signed-off-by: Oleksandr Natalenko 
Reviewed-on: http://review.gluster.org/15167
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Kaushal M

libgfapi: glfd close is not correctly handled for async fop

2016-03-30T14:23:20+00:00

There is chance that before the async fop is complete client can send
a close. libgfapi destroys glfd on close. Therefore it can lead to
crash or unexpected behaviour when the pening fop reaches libgfapi
layer. Currently we don't provide any api to cancel these outstanding
fops neither we check if the glfd is already closed or not.

Therefore as a fix provided refcount for glfd. Each fop (sync or async)
will take a ref and once the fop is complete it will unref the refcount.
We should not call the registered callback function if glfd is already
closed. To achieve this we maintain state of glfd so that we can safely
take a call if the fd is closed or not.

Backport of commit 88d772c05c45c467bfccebfc51f6a0e0ea9ca287:
> Change-Id: Ibe71b2225312db3f1be66b244fcf8826c70c357d
> BUG: 1303995
> Signed-off-by: Rajesh Joseph 
> Reviewed-on: http://review.gluster.org/13340
> Smoke: Gluster Build System 
> CentOS-regression: Gluster Build System 
> Reviewed-by: Shyamsundar Ranganathan 
> NetBSD-regression: NetBSD Build System 

Change-Id: I1e01690ea72f34c12465eb084d7a1aa9de0d7b83
BUG: 1311578
Signed-off-by: Rajesh Joseph 
Reviewed-on: http://review.gluster.org/13512
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos 
Smoke: Gluster Build System

api: Fix errno being set to EINVAL even on success

2016-02-23T12:48:46+00:00

BUG: 1296007
Change-Id: I7905ac70a537f23e1844c097a24eaa6cb762fb82
Signed-off-by: Prashanth Pai 
Reviewed-on: http://review.gluster.org/12909
Tested-by: NetBSD Build System 
Tested-by: Gluster Build System 
Reviewed-by: jiffin tony Thottan 
Reviewed-by: Kaushal M 
Reviewed-by: Shyamsundar Ranganathan 
Reviewed-on: http://review.gluster.org/13179
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos

libgfapi: Gracefully exit when glfd is invalid

2015-08-26T16:17:19+00:00

This is a backport of: http://review.gluster.org/10759

When glfs_* methods operating on glfd are invoked after calling
glfs_close(), the program segfaults inside __GLFS_ENTRY_VALIDATE_FD
trying to deference glfd->fd->inode which is invalid.

Also, returning EBADF seemed more specific than EINVAL.

BUG: 1240920
Change-Id: I13a92dca52da9a300252b69e026581b3a9e931fd
Signed-off-by: Prashanth Pai 
Reviewed-on-master: http://review.gluster.org/10759
Tested-by: Gluster Build System 
Reviewed-by: Shyamsundar Ranganathan 
Reviewed-on: http://review.gluster.org/11571
Reviewed-by: Niels de Vos 
Reviewed-by: Humble Devassy Chirammal 
Reviewed-by: bipin kunal 
Tested-by: NetBSD Build System

libgfapi: non-default symbol version macros are incorrect

2015-08-20T05:01:21+00:00

default symbol versions are in form glfs_h_lookupat@@GFAPI_2.7.4,
versus old, non-default versions are in the form glfs_h_lookup@GFAPI_2.4.2

I.e. "@@" versus "@"

Backport of:
* Change-Id: I88a6b129558c0b3a6064de7620b3b20425e80bc9
* BUG: 1254863
* http://review.gluster.org/#/c/11955/

Change-Id: I0d53140e03dc2f501ce11d5b2d67373360f2b8b2
BUG: 1254865
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/11956
Reviewed-by: Niels de Vos 
Tested-by: Gluster Build System

rpc: add owner xlator argument to rpc_clnt_new

2015-08-14T10:10:47+00:00

The @owner argument tells RPC layer the xlator that owns
the connection and to which xlator THIS needs be set during
network notifications like CONNECT and DISCONNECT.

Code paths that originate from the head of a (volume) graph and use
STACK_WIND ensure that the RPC local endpoint has the right xlator saved
in the frame of the call (callback pair). This guarantees that the
callback is executed in the right xlator context.

The client handshake process which includes fetching of brick ports from
glusterd, setting lk-version on the brick for the session, don't have
the correct xlator set in their frames. The problem lies with RPC
notifications. It doesn't have the provision to set THIS with the xlator
that is registered with the corresponding RPC programs. e.g,
RPC_CLNT_CONNECT event received by protocol/client doesn't have THIS set
to its xlator. This implies, call(-callbacks) originating from this
thread don't have the right xlator set too.

The fix would be to save the xlator registered with the RPC connection
during rpc_clnt_new. e.g, protocol/client's xlator would be saved with
the RPC connection that it 'owns'. RPC notifications such as CONNECT,
DISCONNECT, etc inherit THIS from the RPC connection's xlator.

Change-Id: I9dea2c35378c511d800ef58f7fa2ea5552f2c409
BUG: 1253212
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/11436
Tested-by: Gluster Build System 
Tested-by: NetBSD Build System 
Reviewed-by: Raghavendra G 
(cherry picked from commit f7668938cd7745d024f3d2884e04cd744d0a69ab)
Reviewed-on: http://review.gluster.org/11908
Reviewed-by: Pranith Kumar Karampuri

gfapi : symlink resolution for glfs_object

2015-06-28T07:53:27+00:00

Generally posix expects symlink should be resolved, before performing an
acl related operation. This patch introduces a new api glfs_h_resolve_symlink()
which will do the same.

backport of http://review.gluster.org/#/c/11410/1

>Change-Id: Ieee645154455a732edfb2c28834021bab4248810
>BUG: 1209735
>Signed-off-by: Jiffin Tony Thottan 

Change-Id: I13a83f37a9e59418fd8eb4bf2d44f828515beabf
BUG: 1236269
Signed-off-by: Jiffin Tony Thottan 
Reviewed-on: http://review.gluster.org/11438
Reviewed-by: Niels de Vos 
Tested-by: NetBSD Build System 
Tested-by: Gluster Build System

libgfapi: introduce bit flags for pthread mutex and cond variables

2015-06-22T09:36:24+00:00

At present stage, the initialization and destroy of conditional
and mutex variables of glfs struct happen in different places and
there is no uniform way of destroying these variables incase
there is a failure when initializing these. The fs mutex and
conditional variables are getting destroyed from glfs_free_from_ctx().
However this destroy is not done by a conditional check inside destroy
function. By introducing bit flags in glfs object, we can make use of the
same (if there is a failure in initialization) in glfs_fini()
which is evolving as one and only function to free fs and ctx resources.
This patch introduce the flags field and set the flags according
to the initialization flow of the mutex and conditional variables
of struct glfs members. Without this patch we are compelled to use
the goto lables and other hacks in init functions to make sure
the resources are freed if there is an error path.

Change-Id: I86e2719fb7ce437419a05699b4f06c14b02d0e69
BUG: 1233651
Signed-off-by: Humble Devassy Chirammal 
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/10120
Reviewed-by: Niels de Vos 
Tested-by: Gluster Build System 
Tested-by: NetBSD Build System
Reviewed-by: Shyamsundar Ranganathan 
(cherry picked from commit bc858473db1e1091b15d3f3d69ac6ba5d20b58e7)
Reviewed-on: http://review.gluster.org/10971
Tested-by: NetBSD Build System 
Reviewed-by: Kaleb KEITHLEY