glusterfs.git/xlators/performance, branch v3.7.18

md-cache: Invalidate cache entry for open() with O_TRUNC

2016-11-04T10:10:36+00:00

When a file is opened with O_TRUNC flag set, its size gets
set to '0'. This case needs to be handled in md-cache to
avoid sending incorrect cached stat.

This is backport of below mainline patch -
http://review.gluster.org/#/c/15618/

> Change-Id: I95d1f8a6634734898883ede010c3e7b0b7eb97d9
> BUG: 1382266
> Signed-off-by: Soumya Koduri 
> Reviewed-on: http://review.gluster.org/15618
> Smoke: Gluster Build System 
> Reviewed-by: jiffin tony Thottan 
> Tested-by: jiffin tony Thottan 
> NetBSD-regression: NetBSD Build System 
> CentOS-regression: Gluster Build System 
> Reviewed-by: Kaleb KEITHLEY 
> (cherry picked from commit 6ca5d6382f03685b31b12accb095093cf1486603)

Change-Id: I00d2b0a6dbafa690235bbc7cd714ec7cc8a13808
BUG: 1391451
Signed-off-by: Soumya Koduri 
Reviewed-on: http://review.gluster.org/15772
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System 
Reviewed-by: Kaleb KEITHLEY

performance/write-behind: fix flush stuck by former failed writes

2016-11-03T09:28:17+00:00

the issue is happened in this case:
assume a file is opened with fd1 and fd2.
1. some WRITE opto fd1 got error, they were add back to 'todo' queue
   because of those error.
2. fd2 closed, a FLUSH op is send to write-behind.
3. FLUSH can not be unwind because it's not a legal waiter for those
   failed write(as func __wb_request_waiting_on() say). and those failed
   WRITE also can not be ended if fd1 is not closed. fd2 stuck in close
   syscall.

to resolve this issue, we can change the way we determine 2 requests is
'conflict': flush/fsync is not conflict with those write that is not
belonged to them. so __wb_pick_winds() can wind the FLUSH op.

below is some information when the stuck issue happen:
glusterdump logs:
[xlator.performance.write-behind.wb_inode]
path=/ltp-F9eG0ZSOME/rw-buffered-16436
inode=0x7fdbe8039b9c
window_conf=1048576
window_current=249856
transit-size=0
dontsync=0

[.WRITE]
request-ptr=0x7fdbe8020200
refcount=1
wound=no
generation-number=4
req->op_ret=-1
req->op_errno=116
sync-attempts=3
sync-in-progress=no
size=131072
offset=1220608
lied=-1
append=0
fulfilled=0
go=0

[.WRITE]
request-ptr=0x7fdbe8068c30
refcount=1
wound=no
generation-number=5
req->op_ret=-1
req->op_errno=116
sync-attempts=2
sync-in-progress=no
size=118784
offset=1351680
lied=-1
append=0
fulfilled=0
go=0

[.FLUSH]
request-ptr=0x7fdbe8021cd0
refcount=1
wound=no
generation-number=6
req->op_ret=0
req->op_errno=0
sync-attempts=0

gdb detail about above 3 requests:
(gdb) print *((wb_request_t *)0x7fdbe8021cd0)
$2 = {all = {next = 0x7fdbe803a608, prev = 0x7fdbe8068c30}, todo = {next
= 0x7fdbe803a618, prev = 0x7fdbe8068c40}, lie = {next = 0x7fdbe8021cf0,
    prev = 0x7fdbe8021cf0}, winds = {next = 0x7fdbe8021d00, prev =
0x7fdbe8021d00}, unwinds = {next = 0x7fdbe8021d10, prev =
0x7fdbe8021d10}, wip = {
    next = 0x7fdbe8021d20, prev = 0x7fdbe8021d20}, stub =
0x7fdbe80224dc, write_size = 0, orig_size = 0, total_size = 0, op_ret =
0, op_errno = 0,
  refcount = 1, wb_inode = 0x7fdbe803a5f0, fop = GF_FOP_FLUSH, lk_owner
= {len = 8, data = "W\322T\f\271\367y$", '\000' },
  iobref = 0x0, gen = 6, fd = 0x7fdbe800f0dc, wind_count = 0, ordering =
{size = 0, off = 0, append = 0, tempted = 0, lied = 0, fulfilled = 0,
    go = 0}}
(gdb) print *((wb_request_t *)0x7fdbe8020200)
$3 = {all = {next = 0x7fdbe8068c30, prev = 0x7fdbe803a608}, todo = {next
= 0x7fdbe8068c40, prev = 0x7fdbe803a618}, lie = {next = 0x7fdbe8068c50,
    prev = 0x7fdbe803a628}, winds = {next = 0x7fdbe8020230, prev =
0x7fdbe8020230}, unwinds = {next = 0x7fdbe8020240, prev =
0x7fdbe8020240}, wip = {
    next = 0x7fdbe8020250, prev = 0x7fdbe8020250}, stub =
0x7fdbe8062c3c, write_size = 131072, orig_size = 4096, total_size = 0,
op_ret = -1,
  op_errno = 116, refcount = 1, wb_inode = 0x7fdbe803a5f0, fop =
GF_FOP_WRITE, lk_owner = {len = 8, data = '\000' },
  iobref = 0x7fdbe80311a0, gen = 4, fd = 0x7fdbe805c89c, wind_count = 3,
ordering = {size = 131072, off = 1220608, append = 0, tempted = -1,
    lied = -1, fulfilled = 0, go = 0}}
(gdb) print *((wb_request_t *)0x7fdbe8068c30)
$4 = {all = {next = 0x7fdbe8021cd0, prev = 0x7fdbe8020200}, todo = {next
= 0x7fdbe8021ce0, prev = 0x7fdbe8020210}, lie = {next = 0x7fdbe803a628,
    prev = 0x7fdbe8020220}, winds = {next = 0x7fdbe8068c60, prev =
0x7fdbe8068c60}, unwinds = {next = 0x7fdbe8068c70, prev =
0x7fdbe8068c70}, wip = {
    next = 0x7fdbe8068c80, prev = 0x7fdbe8068c80}, stub =
0x7fdbe806746c, write_size = 118784, orig_size = 4096, total_size = 0,
op_ret = -1,
  op_errno = 116, refcount = 1, wb_inode = 0x7fdbe803a5f0, fop =
GF_FOP_WRITE, lk_owner = {len = 8, data = '\000' },
  iobref = 0x7fdbe8052b10, gen = 5, fd = 0x7fdbe805c89c, wind_count = 2,
ordering = {size = 118784, off = 1351680, append = 0, tempted = -1,
    lied = -1, fulfilled = 0, go = 0}}

you can see they are all on 'todo' queue, and FLUSH op fd is not the
same WRITE op fd.

> Change-Id: Id687f9cd3b9f281e1a97c83f1ce981ede272b8ab
> BUG: 1372211
> Signed-off-by: Ryan Ding 

Change-Id: Id687f9cd3b9f281e1a97c83f1ce981ede272b8ab
BUG: 1390840
Signed-off-by: Ryan Ding 
Reviewed-on: http://review.gluster.org/15763
Tested-by: Raghavendra G 
Reviewed-by: Raghavendra G 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

performance/write-behind: remove the request from liability queue in

2016-10-18T05:37:02+00:00

wb_fulfill_request

Before this patch, a request is removed from liability queue only when
ref count of request hits 0. Though, wb_fulfill_request does an unref,
it need not be the last unref and hence the request may survive in
liability queue till the last unref. Let,

T1: the time at which wb_fulfill_request is invoked
T2: the time at which last unref is done on request

Let's consider a case of T2 > T1. In the time window between T1 and
T2, any other request (waiter) conflicting with request in liability
queue (blocker - basically a write which has been lied) is blocked
from winding. If T2 happens to be when wb_do_unwinds is invoked, no
further processing of request list happens and "waiter" would get
blocked forever. An example imaginary sequence of events is given
below:

1. A write request w1 is picked up for unwinding in __wb_pick_unwinds
   (but unwind is not done _yet_ and hence reference
   remains). However, w1 is moved to liability queue. Let's call this
   invocation of wb_process_queue by wb_writev as PQ1.

2. A flush (f1) request hits write behind. Since the liability queue
   of inode is not empty, f1 is not picked for unwinding. Let's call
   the invocation of wb_process_queue by wb_flush as PQ2.

3. PQ2 continues and picks w1 for fulfilling and invokes
   wb_fulfill. As part of successful wb_fulfill_cbk,
   wb_fulfill_request (w1) is invoked. But, w1 is not freed (and hence
   not removed from liability queue) as w1 is not unwound _yet_ and a
   ref remains (PQ1 has not invoked wb_do_unwinds _yet_).

4. wb_fulfill_cbk (triggered by PQ2) invokes a wb_process_queue (let's
   say PQ3). f1 is not resumed in PQ3 as w1 is still in liability
   queue. At this time, PQ2 and PQ3 are complete.

5. PQ1 continues, unwinds w1 and does last unref on w1 and w1 is freed
   (and removed from liability queue). Since PQ1 didn't invoke
   wb_fulfill on any other write requests, there won't be any future
   codepaths that would invoke wb_process_queue and f1 is stuck
   forever.

With this fix, w1 is removed from liability queue in step 3 above and
PQ3 resumes f1 in step 4 (as there are no requests conflicting with f1
in liability queue during execution of PQ3).

> Signed-off-by: Raghavendra G 
> BUG: 1379655
> Change-Id: Idacda1fcd520ac27f30224f8dfe8360dba6ac6cb
> Reviewed-on: http://review.gluster.org/15579
> CentOS-regression: Gluster Build System 
> NetBSD-regression: NetBSD Build System 
> Smoke: Gluster Build System 
(cherry picked from commit a8b2a981881221925bb5edfe7bb65b25ad855c04)

Signed-off-by: Raghavendra G 
BUG: 1385622
Change-Id: Idacda1fcd520ac27f30224f8dfe8360dba6ac6cb
Reviewed-on: http://review.gluster.org/15657
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

performance/open-behind: Pass O_DIRECT flags for anon fd reads when required

2016-09-23T14:46:33+00:00

        Backport of: http://review.gluster.org/15537
        cherry-picked from a412a4f50d8ca2ae68dbfa93b80757889150ce99

Writes are already passing the correct flags at the time of open().

Also, make io-cache honor direct-io for anon-fds with
O_DIRECT flag during reads.

Change-Id: I221d6e8e7431931a0c1fc93f1a886a62ab58d0ca
BUG: 1378695
Signed-off-by: Krutika Dhananjay 
Reviewed-on: http://review.gluster.org/15551
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Pranith Kumar Karampuri

readdir-ahead: Prefetch xattrs needed by md-cache

2016-05-11T11:02:57+00:00

Problem:
Negative cache feature implementation in md-cache requires xattrs
returned by posix to be intercepted for every call that can possibly
return xattrs. This includes readdirp(). This is crucial to treat
missing keys in cache as a case of negative entry (returns ENODATA)

md-cache puts names of xattrs that it wants to cache in xdata and
passes it down to posix which returns the specified xattrs in the
callback. This is done in lookup() and readdirp(). Hence, a xattr
that is cached can be invalidated during readdirp_cbk too.

This is based on the assumption that readdirp() will always return
all xattrs that md-cache is interested in. However, this is not the
case when readdirp() call is served from readdir-ahead's cache.
readdir-ahead xlator will pre-fetch dentries during opendir_cbk
and readdirp. These internal readdirp() calls made by readdir-ahead
xlator does not set xdata in it's requests. Hence, no xattrs are
fetched and stored in it's internal cache.

This causes metadata loss in gluster-swift. md-cache returns ENODATA
during getxattr() call even though the xattr for that object exists on
the brick. On receiving ENODATA, gluster-swift will create new metadata
and do setxattr(). This results in loss of information stored in
existing xattr.

Fix:
During opendir, md-cache will communicate to readdir-ahead asking it
to store the names of xattrs it's interested in so that readdir-ahead
can fetch those in all subsequent internal readdirp() calls issued by
it. This stored names of xattrs is invalidated/updated on the next
real readdirp() call issued by application. This readdirp() call will
have xdata set correctly by md-cache xlator.

> Reviewed-on: http://review.gluster.org/14214
> Tested-by: Prashanth Pai 
> NetBSD-regression: NetBSD Build System 
> CentOS-regression: Gluster Build System 
> Tested-by: Gluster Build System 
> Smoke: Gluster Build System 
> Reviewed-by: Raghavendra G 
> Tested-by: Raghavendra G 

BUG: 1334700
Change-Id: I32d46f93a99d4ec34c741f3c52b0646d141614f9
(cherry picked from commit 0c73e7050c4d30ace0c39cc9b9634e9c1b448cfb)
Reviewed-on: http://review.gluster.org/14282
Tested-by: Prashanth Pai 
NetBSD-regression: NetBSD Build System 
Tested-by: Gluster Build System 
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System 
Reviewed-by: Raghavendra G

performance/write-behind: guaranteed retry after a short write

2016-05-05T03:27:33+00:00

* Don't mark the request with a fake EIO after a short write.
* retry the remaining buffer at least once before unwinding reply to
  application. This way we capture correct error from backend (ENOSPC,
  EDQUOT etc).

Thanks to "Vijaikumar Mallikarjuna" for the test
script.

Change-Id: I73a18b39b661a7424db1a7855a980469a51da8f9
BUG: 1332790
Signed-off-by: Raghavendra G 
Reviewed-on: http://review.gluster.org/14196
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

md-cache: Cache gluster-swift metadata

2016-03-31T07:48:53+00:00

> BUG: 1317785
> Change-Id: Ie02b8fc294802f8fdf49dee8bf97f1e6177d92bd
> Signed-off-by: Prashanth Pai 
> Reviewed-on: http://review.gluster.org/13735
> Smoke: Gluster Build System 
> Reviewed-by: Poornima G 
> NetBSD-regression: NetBSD Build System 
> CentOS-regression: Gluster Build System 
> Reviewed-by: Niels de Vos 
> Reviewed-by: Gaurav Kumar Garg 

BUG: 1317788
Change-Id: I86efca6a829cdda70ec7ed7fe0a16b73c25888c3
Signed-off-by: Prashanth Pai 
Reviewed-on: http://review.gluster.org/13753
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos 
Smoke: Gluster Build System

performance/open-behind: Fix fdctx dump NULL dereference

2016-03-07T08:31:38+00:00

Also printing flags correctly in statedump now

 >Change-Id: Ibfdd74aab5643ecc47d0a88f109d5d1050685f5a
 >BUG: 1294051
 >Signed-off-by: Pranith Kumar K 
 >Reviewed-on: http://review.gluster.org/13076
 >Smoke: Gluster Build System 
 >NetBSD-regression: NetBSD Build System 
 >CentOS-regression: Gluster Build System 
 >Reviewed-by: Raghavendra G 

BUG: 1315140
Change-Id: Ib11306831b930cddaa2c6e293be5d00dff41e880
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/13615
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Raghavendra G 
Tested-by: Raghavendra G 
CentOS-regression: Gluster Build System

performance/write-behind: retry "failed syncs to backend"

2016-02-16T09:09:34+00:00

1. When sync fails, the cached-write is still preserved unless there
   is a flush/fsync waiting on it.

2. When a sync fails and there is a flush/fsync waiting on the
   cached-write, the cache is thrown away and no further retries will
   be made. In other words flush/fsync act as barriers for all the
   previous writes. The behaviour of fsync acting as a barrier is
   controlled by an option (see below for details). All previous
   writes are either successfully synced to backend or forgotten in
   case of an error. Without such barrier fop (especially flush which
   is issued prior to a close), we end up retrying for ever even after
   fd is closed.

3. If a fop is waiting on cached-write and syncing to backend fails,
   the waiting fop is failed.

4. sync failures when no fop is waiting are ignored and are not
   propagated to application. For eg.,
   a. first attempt of sync of a cached-write w1 fails
   b. second attempt of sync of w1 succeeds

   If there are no fops dependent on w1 are issued b/w a and b,
   application won't know about failure encountered in a.

5. The effect of repeated sync failures is that, there will be no
   cache for future writes and they cannot be written behind.

fsync as a barrier and resync of cached writes post fsync failure:
==================================================================
Whether to keep retrying failed syncs post fsync is controlled by an
option "resync-failed-syncs-after-fsync". By default, this option is
set to "off".

If sync of "cached-writes issued before fsync" (to backend) fails,
this option configures whether to retry syncing them after fsync or
forget them. If set to on, cached-writes are retried till a "flush"
fop (or a successful sync) on sync failures. fsync itself is failed
irrespective of the value of this option, when there is a sync failure
of any cached-writes issued before fsync.

Change-Id: I6097c0257bfb9ee5b1f616fbe6a0576ae9af369a
Signed-off-by: Raghavendra G 
BUG: 1293534
Signed-off-by: Raghavendra Talur 
Reviewed-on: http://review.gluster.org/13057
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

all: reduce "inline" usage

2016-01-18T09:02:34+00:00

There are three kinds of inline functions: plain inline, extern inline,
and static inline.  All three have been removed from .c files, except
those in "contrib" which aren't our problem.  Inlines in .h files, which
are overwhelmingly "static inline" already, have generally been left
alone.  Over time we should be able to "lower" these into .c files, but
that has to be done in a case-by-case fashion requiring more manual
effort.  This part was easy to do automatically without (as far as I can
tell) any ill effect.

In the process, several pieces of dead code were flagged by the
compiler, and were removed.

backport of Change-Id: I56a5e614735c9e0a6ee420dab949eac22e25c155,
http://review.gluster.org/11769, BUG: 1245331

Change-Id: Iba1efb0bc578ea4a5e9bf76b7bd93dc1be9eba44
BUG: 1283302
Signed-off-by: Kaleb S KEITHLEY 
Reviewed-on: http://review.gluster.org/12646
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos