glusterfs.git/libglusterfs, branch v3.11.0beta1

dht: send lookup on old name inside rename with bname and pargfid

2017-04-29T14:28:38+00:00

Inside rename, a lookup is done on the source name to make sure that
the file is there. But we used to do a gfid based lookup and hence,
even if the source name was renamed to a new name from some other client,
lookup will be successful as server3_3_lookup will fetch the new path
based on the gfid.

So even if the source file does not exist any more rename will carry on,
and as server3_3_link(destination is hashed to a different brick other
than source cached scenario) also does gfid based resolve, it wont
detect that the source name does not exist and hardlink creation will be
successful (since gfid based resolve will get the new dentry).

To solve this problem, do a name based lookup inside rename. So that
rename will fail right away if the source does not exist.

Change-Id: Ieba8bdd6675088dbf18de90ed4622df043d163bd
BUG: 1412135
Signed-off-by: Susant Palai 
Reviewed-on: https://review.gluster.org/16375
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: N Balachandran 
CentOS-regression: Gluster Build System 
Reviewed-by: Raghavendra G

cluster/dht: rebalance perf enhancement

2017-04-29T14:28:19+00:00

Problem: Throttle settings "normal" and "aggressive" for rebalance
did not have performance difference.

normal mode spawns $(no. of cores - 4)/2 threads and aggressive
spawns $(no. of cores - 4) threads. Though aggressive mode has twice
the number of threads compared to that of normal mode, there was no
performance gain when switched to aggressive mode from normal mode.

RCA:
During the course of debugging the above problem, we tried assigning
migration job to migration threads spawned by rebalance, rather than
synctasks(as there is more overhead associated to manage the task
queue and threads). This gave us a significant improvement over rebalance
under synctasks. This patch does not really gurantee that there will be a
clear performance difference between normal and aggressive mode, but this
patch certainly maximized the disk utilization for 1GBfiles run.

Results:

Test enviroment:
Gluster Config:
Number of Bricks: 2 (one brick per disk(RAID-6 12 disk))
Bricks:
Brick1: server1:/brick/test1/1
Brick2: server2:/brick/test1/1
Options Reconfigured:
performance.readdir-ahead: on
server.event-threads: 4
client.event-threads: 4

1000 files with 1GB each were created/renamed such that all files will have
server1 as cached and server2 as hashed, so that all files will be migrated.

Test machines had 24 cores each.

Results  with/without synctask based migration:
-----------------------------------------------

mode                    normal(10threads)          aggressive(20threads)

timetaken               0:55:30 (h:m:s)            0:56:3 (h:m:s)
withsynctask

timetaken
with migrator           0:38:3 (h:m:s)             0:23:41 (h:m:s)
threads

From above table it can be seen that, there is a clear 2x perf gain between
rebalance with synctask vs rebalance with migrator threads.

Additionally this patch modifies the code so that caller will have the exact error
number returned by dht_migrate_file(earlier the errno meaning was overloaded). This
will help avoiding scenarios where migration failure due to ENOENT, can result in
rebalance abort/failure.

Change-Id: I8904e2fb147419d4a51c1267be11a08ffd52168e
BUG: 1420166
Signed-off-by: Susant Palai 
Reviewed-on: https://review.gluster.org/16427
Smoke: Gluster Build System 
Reviewed-by: N Balachandran 
Reviewed-by: Raghavendra G 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

libglusterfs/stack.h: reduce duplication of code

2017-04-27T14:54:40+00:00

* Use STACK_UNWIND_STRICT everywhere.
* Provide STACK_WIND_COMMON as both STACK_WIND_COOKIE
  and STACK_WIND differ by just 1 line and 1 option.

Updates gluster/glusterfs#137

Change-Id: Ifbb6b9c4702b02f4a02834824f509fd10c78f0ce
Signed-off-by: Amar Tumballi 
Reviewed-on: https://review.gluster.org/16915
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Jeff Darcy

feature/dht: Directory synchronization

2017-04-26T09:00:34+00:00

Design doc: https://review.gluster.org/16876

Directory creation is now synchronized with blocking inodelk of the
parent on the hashed subvolume followed by the entrylk on the hashed
subvolume between dht_mkdir, dht_rmdir, dht_rename_dir and lookup
selfheal mkdir.

To maintain internal consistency of directories across all subvols of
dht, we need locks. Specifically we are interested in:

 1. Consistency of layout of a directory. Only one writer should modify
    the layout at a time. A writer (layout setting during directory heal
    as part of lookup) shouldn't modify the layout while there are
    readers (all other fops like create, mkdir etc., which consume
    layout) and readers shouldn't read the layout while a writer is in
    progress. Readers can read the layout simultaneously. Writer takes
    a WRITE inodelk on the directory (whose layout is being modified)
    across ALL subvols. Reader takes a READ inodelk on the directory
    (whose layout is being read) on ANY subvol.

 2. Consistency of directory namespace across subvols. The path and
    associated gfid should be same on all subvols. A gfid should not be
    associated with more than one path on any subvol. All fops that can
    change directory names (mkdir, rmdir, renamedir, directory creation
    phase in lookup-heal) takes an entrylk on hashed subvol of the
    directory.

 NOTE1: In point 2 above, since dht takes entrylk on hashed subvol of a
        directory, the transaction itself is a consumer of layout on
        parent directory. So, the transaction is a reader of parent
        layout and does an inodelk on parent directory just like any
        other layout reader. So a mkdir (dir/subdir) would:

     > Acquire a READ inodelk on "dir" on any subvol.
     > Acquire an entrylk (dir, "subdir") on hashed subvol of "subdir".
     > creates directory on hashed subvol and possibly on non-hashed subvols.
     > UNLOCK (entrylk)
     > UNLOCK (inodelk)

 NOTE2: mkdir fop while setting the layout of the directory being created
        is considered as a reader, but NOT a writer. The reason is for
        a fop which can consume the layout of a directory to come either
        of the following conditions has to be true:

     > mkdir syscall from application has to complete. In this case no
       need of synchronization.
     > A lookup issued on the directory racing with mkdir has to complete.
       Since layout setting by a lookup is considered as a writer, only
       one of either mkdir or lookup will set the layout.

Code re-organization:
   All the lock related routines are moved to "dht-lock.c" file.
   New wrapper function is introduced to take blocking inodelk
   followed by entrylk 'dht_protect_namespace'

Updates #191
Change-Id: I01569094dfbe1852de6f586475be79c1ba965a31
Signed-off-by: Kotresh HR 
BUG: 1443373
Reviewed-on: https://review.gluster.org/15472
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Raghavendra G 
Smoke: Gluster Build System

libglusterfs: accept random volname in glusterfs_graph_prepare()

2017-04-26T01:18:56+00:00

When the call to glfs_new("volname") passes a name for the volume and it
does not match the name of the subvolume in the graph, glfs_init() will
fail. This is easily reproducible by a gfapi program that loads the
volume from a .vol file, and not from a GlusterD server.

Change-Id: I33e77fbee7d12eaefe7c384fad6aecfa3582ea5a
BUG: 1425623
Signed-off-by: Niels de Vos 
Reviewed-on: https://review.gluster.org/16796
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Kaleb KEITHLEY 
Reviewed-by: Prashanth Pai 
Reviewed-by: Shyamsundar Ranganathan

remove redundant function definition

2017-04-25T15:00:04+00:00

function definition is duplicated

erase second sys_ftruncate() definition

No test cases

Change-Id: I3eead1380b527b8b0e480f45b39e0c4bc9b2b92a
Signed-off-by: Jungyeon Yoon 
Reviewed-on: https://review.gluster.org/17106
Smoke: Gluster Build System 
Tested-by: Prashanth Pai 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Jeff Darcy

Implement negative lookup cache

2017-04-20T04:18:52+00:00

Before creating any file negative lookups(1 in Fuse, 4 in SMB etc.)
are sent to verify if the file already exists. By serving these
lookups from the cache when possible, increases the create
performance by multiple folds in SMB access and some percentage
in Fuse/NFS access.

Feature page: https://review.gluster.org/#/c/16436

Updates #82
Change-Id: Ib1c0e7ac7a386f943d84f6398c27f9a03665b2a4
BUG: 1442569
Signed-off-by: Poornima G 
Reviewed-on: https://review.gluster.org/16952
Reviewed-by: Pranith Kumar Karampuri 
Tested-by: Pranith Kumar Karampuri 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

dht: Add readdir-ahead in rebalance graph if parallel-readdir is on

2017-04-18T06:16:11+00:00

Issue:
The value of linkto xattr is generally the name of the dht's
next subvol, this requires that the next subvol of dht is not
changed for the life time of the volume. But with parallel
readdir enabled, the readdir-ahead loaded below dht, is optional.
The linkto xattr for first subvol, when:
- parallel readdir is enabled : "-readdir-head-0"
- plain distribute volume : "-client-0"
- distribute replicate volume : "-afr-0"

The value of linkto xattr is "-readdir-head-0" when
parallel readdir is enabled, and is "-client-0" if
its disabled. But the dht_lookup takes care of healing if it
cannot identify which linkto subvol, the xattr points to.

In dht_lookup_cbk, if linkto xattr is found to be "-client-0"
and parallel readdir is enabled, then it cannot understand the
value "-client-0" as it expects "-readdir-head-0".
In that case, dht_lookup_everywhere is issued and then the linkto file
is unlinked and recreated with the right linkto xattr. The issue is
when parallel readdir is enabled, mount point accesses the file
that is currently being migrated. Since rebalance process doesn't
have parallel-readdir feature, it expects "-client-0"
where as mount expects "-readdir-head-0". Thus at some point
either the mount or rebalance will fail.

Solution:
Enable parallel-readdir for rebalance as well and then do not
allow enabling/disabling parallel-readdir if rebalance is in
progress.

Change-Id: I241ab966bdd850e667f7768840540546f5289483
BUG: 1436090
Signed-off-by: Poornima G 
Reviewed-on: https://review.gluster.org/17056
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Atin Mukherjee 
Reviewed-by: Raghavendra G

rpc: add options to manage socket keepalive lifespan

2017-04-12T09:44:01+00:00

Problem:
Default values for handling socket timeouts for brick responses are
insufficient for aggressive applications such as databases.

Solution:
Add 1:1 gluster options for keepalive, keepalive-idle,
keepalive-interval and keepalive-timeout as per the socket level options
available as per tcp(7) man page.

Default values for options are NOT agressive and continue to be values
which result in default timeout when only the keep alive option is
turned on.

These options are Linux specific and will not be applicable to the
*BSDs.

Change-Id: I2a08ecd949ca8ceb3e090d336ad634341e2dbf14
BUG: 1426059
Signed-off-by: Milind Changire 
Reviewed-on: https://review.gluster.org/16731
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Raghavendra G

mem-pool: use gf_atomic_t for atomic counters

2017-04-10T15:05:56+00:00

Reduce the usage of __sync_fetch_and_add() builtins in mem-pool. The new
gf_atomic_t type can be used instead, so that the architecture and
compiler specific builtins are hidden from the mem-pool implementation.

BUG: 1437037
Change-Id: Icbeeb187dd2b835b35f32f54f821ceddfc7b2638
Signed-off-by: Niels de Vos 
Reviewed-on: https://review.gluster.org/17012
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System 
Reviewed-by: Kaleb KEITHLEY 
Reviewed-by: Amar Tumballi