glusterfs.git/xlators/features/upcall/src/upcall.c, branch v3.13.0rc0

gfapi: Duplicate the buffer sent in setxattr calls

2017-08-07T16:28:45+00:00

Issue:
The caller of glfs_setxattr sends a buffer to set as the value.
We create a dict in which the pointer to the value is set.
Underlying layers like md-cache take a ref on this dict to store
the value for a longer time. But the moment setxattr is complete,
the caller of glfs_setxattr can free the value memory.

Solution:
memcpy the setxattr value to the gluster buffer.

Change-Id: I58753fe702e8b7d0f6c4f058714c65d0ad5d7a0a
BUG: 1477488
Signed-off-by: Poornima G 
Reviewed-on: https://review.gluster.org/17967
Reviewed-by: soumya k 
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Jeff Darcy

upcall: Update the access time in missing cases

2017-06-09T11:30:31+00:00

Issue: In fops like rename, link, unlink etc, the parent
dirrs' client access time was not being updated. And in fops like
create, link, symlink etc. the new file/dirs' client access time was
not updated.

Solution: Update the client access time for both parent and new entry.

Change-Id: Id9f63583216ae857f6251dca15797ac66fa85430
BUG: 1458127
Signed-off-by: Poornima G 
Reviewed-on: https://review.gluster.org/17450
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos

upcall: correct the cleanup path in init() when GF_CALLOC() fails

2017-04-10T15:19:24+00:00

Coverity found that "priv" can be NULL when the 1st GF_CALLOC() fails,
and still is being used with "priv->xattrs" before the functon returns.

While cleaning this up, also removing the log message for out of memory,
as this is already logged through GF_CALLOC().

BUG: 789278
Change-Id: I887eaa9136dc25a39c107cd2152b1ba11f9fa925
Signed-off-by: Niels de Vos 
Reviewed-on: https://review.gluster.org/17023
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: soumya k 
CentOS-regression: Gluster Build System 
Reviewed-by: Amar Tumballi

marker: Fix inode value in loc, in setxattr fop

2017-02-20T05:11:42+00:00

On recieving a rename fop, marker_rename() stores the,
oldloc and newloc in its 'local' struct, once the rename
is done, the xtime marker(last updated time) is set on
the file, but sending a setxattr fop. When upcall
receives the setxattr fop, the loc->inode is NULL and
it crashes. The loc->inode can be NULL only in one valid
case, i.e. in rename case where the inode of new loc
can be NULL. Hence, marker should have filled the inode
of the new_loc before issuing a setxattr.

marker_rename_cbk was already fixed in a previous commit.
Fixing marker_rename_done to send valid inode in this commit.

Also in upcall check for NULL inode so that there is no crash.

Change-Id: I3ed2a05118fed3367dfe3251ce4477310cb480d0
BUG: 1422776
Signed-off-by: Poornima G 
Reviewed-on: https://review.gluster.org/16633
Reviewed-by: Kotresh HR 
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: soumya k 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Raghavendra G

upcall: Resolve dict leak from up_(f)removexattr in upcall code path

2017-01-16T09:32:13+00:00

Problem: In up_(f)removexattr() dict_for_key_value() is used to create a
         new dict. This dict is not correctly unref'd and gets leaked.

Solution: To avoid the leak up_(f)removexattr() now also does a
          dict_unref() on the newly created dict.

While reviewing the code in up_(f)setxattr() for a similar problem, it
was noticed that there is an extra dict created. There is no need for
this copy, upcall_local_init() can just take the dict that was passed as
argument to the FOP.

BUG: 1412917
Change-Id: I5bb9a7d99f5087af11c19ae722de62bdb5ad1498
Signed-off-by: Mohit Agrawal 
Reviewed-on: http://review.gluster.org/16392
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos 
Smoke: Gluster Build System

md-cache, afr: Reduce the window of stale read

2016-10-20T07:07:55+00:00

Problem:
Consider a replica setup, where one mount writes data to a
file and the other mount reads the file. In afr, read operations
are not transaction based, a brick(read subvolume) is chosen as
a part of lookup or other operations, read is always wound only
to the read subvolume, even if there was write from a different client
that failed on this brick. This stale read continues until there is
a lookup or any write operation from the mount point. Currently, this
is not a major issue, as a lookup is issued before every read and it will
switch the read subvolume to a correct one. But with the plan of
increasing md-cache timeout to 600s, the stale read problem will be
more pronounced, i.e. stale read can continue for 600s(or more if cascaded
with readdirp), as there will be no lookups.

Solution:
Afr doesn't have any built-in solution for stale read(without affecting
the performance). The solution that came up, was to use upcall. When a file
on any brick is marked bad for the first time, upcall sends a notification
to all the clients that had recently accessed the file. The solution has
2 parts:
- Identifying when a file is marked bad, on any of the bricks,
  for the first time
- Client side actions on recieving the notifications

Identifying when a file is marked bad on any of the bricks for the first time:
-----------------------------------------------------------------------------
The idea is to track xattrop in upcall. xattrop currently comes with 2 afr
xattrs - afr dirty bit and afr pending xattrs.
   Dirty xattr is set to 1 before every write, and is unset if write succeeds.
In certain scenarios, dirty xattr can be 0 and still the file could be bad
copy. Hence do not track dirty xattr.
   Pending xattr is set on the good copy, indicating the other bricks that have
bad copy. It is still not as simple as, notifying when any of the pending xattrs
change. It could lead to flood of notifcations, in case the other brick is
completely down or consistantly failing. Hence it is important to notify only
once, the first time a good copy is marked bad.

Client side actions on recieving pending xattr change, notification:
--------------------------------------------------------------------
md-cache will invalidate the cache of that file, so that further lookup is
passed down to afr and hence update the read subvolume. Invalidating only in
md-cache is not enough, consider the folling oder of opertaions:
- pending xattr invalidation - invalidate md-cache
- readdirp on the bad read subvolume - fill md-cache
- lookup (served from md-cache)
- read - wound to the old read subvol.
Hence, along with invalidating md-cache, it is very important to reset the
read subvolume for that file, in afr.

Design Credit: Anuradha Talur, Ravishankar N

1. xattrop doesn't carry info saying post op/pre op.
2. Pre xattrop will have 0 value for all pending xattrs,
   the cbk of pre xattrop carries the on-disk xattr value.
   Non zero indicated healing is required.
3. Post xattrop will have non zero value for any of the
   pending xattrs, if the fop failed on any of the bricks.

Change-Id: I469cbc111714c433984fe1c922be2ef113c25804
BUG: 1211863
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/15398
Reviewed-by: Pranith Kumar Karampuri 
Tested-by: Pranith Kumar Karampuri 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

upcall: Mark the clients as accessed on readdirp entries

2016-08-31T13:44:01+00:00

Currently when a client performs a readdirp it is not stored
in upcall, as one of the clients that have accessed the files.
Hence, when any other client modifies the file, the client that
had performed readdirp will not get any notifications.

Fix this by adding the clients to upcall database when they
perform readdirp.

Change-Id: I7767f1e26bf1bd1f67702a6d01f8aa64526ccc46
BUG: 1369430
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/15313
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: soumya k 
Reviewed-by: Niels de Vos

md-cache: Register the list of xattrs with cache-invalidation

2016-08-31T06:07:01+00:00

Issue:
md-cache caches a specified list of xattrs, and when cache invalidation
is enabled, it makes sense to recieve invalidation only when those xattrs
are modified by other clients. But the current implementation of upcall
is that, it will send invalidation when any of the on-disk xattrs is modified.

Solution:
md-cache sends a list of xattrs that it is interested in, to upcall by
issuing an ipc(). The challenge here is to make sure everytime a brick
goes offline and comes back up, the ipc() needs to be issued to the
bricks. Hence ipc() is sent from md-cache every time there is a
CHILD_UP/CHILD_MODIFIED event.

TODO:
There will be patches following, in cluster xlators, to implement ipc fop.

Change-Id: I6efcf3df474f5ce6eabd3d6694c00c7bd89bc25d
BUG: 1211863
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/15002
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Rajesh Joseph 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Prashanth Pai 
Reviewed-by: Raghavendra G

features/upcall: segment fault while join thread reaper_thr in fini()

2016-08-29T12:13:49+00:00

reaper_thr thread may not be started according to option
'cache-invalidation', if it's not started, join it in fini will cause a
segment fault.

Change-Id: I1c145a5feb137767880a08e79f810537283fb6b9
BUG: 1369524
Signed-off-by: Ryan Ding 
[ndevos: check .reaper_init_done and make it a boolean]
Reviewed-on: http://review.gluster.org/15298
Smoke: Gluster Build System 
Reviewed-by: soumya k 
Reviewed-by: Niels de Vos 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

upcall: fix unused variable warnings/errors

2016-08-25T12:11:31+00:00

http://review.gluster.org/14085 fixes a/the "leak" - via the
generated rpc/xdr headers - of pragmas that mask these warnings.

However 14085 won't pass the smoke test until all the warnings are
fixed.

Change-Id: I887aa033f00ab67f73c7d7a7f1b3054d43bffc49
BUG: 1369124
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/15252
Reviewed-by: Niels de Vos 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System