Problem:
AFR doesn't delay post-op for fsync fop. For fsync heavy workloads
this leads to un-necessary fxattrop/finodelk for every fsync leading
to bad performance.

Fix:
Have delayed post-op for fsync. Add special flag in xdata to indicate
that afr shouldn't delay post-op in cases where either the
process will terminate or graph-switch would happen. Otherwise it leads
to un-necessary heals when the graph-switch/process-termination
happens before delayed-post-op completes.

Fixes: #1253
Change-Id: I531940d13269a111c49e0510d49514dc169f4577
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

There was a critical flaw in the previous implementation of open-behind.

When an open is done in the background, it's necessary to take a
reference on the fd_t object because once we "fake" the open answer,
the fd could be destroyed. However as long as there's a reference,
the release function won't be called. So, if the application closes
the file descriptor without having actually opened it, there will
always remain at least 1 reference, causing a leak.

To avoid this problem, the previous implementation didn't take a
reference on the fd_t, so there were races where the fd could be
destroyed while it was still in use.

To fix this, I've implemented a new xlator cbk that gets called from
fuse when the application closes a file descriptor.

The whole logic of handling background opens have been simplified and
it's more efficient now. Only if the fop needs to be delayed until an
open completes, a stub is created. Otherwise no memory allocations are
needed.

Correctly handling the close request while the open is still pending
has added a bit of complexity, but overall normal operation is simpler.

Change-Id: I6376a5491368e0e1c283cc452849032636261592
Fixes: #1225
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

This change is a followup to
I510158843e4b1d482bdc496c2e97b1860dc1ba93.

In referred change we pushed log messages about 'weird'
write errors to fuse device out of sight, by reporting
them at Debug loglevel instead of Error (where
'weird' means errno is not POSIX compliant but having
meaningful semantics for FUSE protocol).

This solved the issue of spurious error reporting.
And so far so good: these messages don't indicate
an error condition by themselves. However, when they
come in high repetitions, that indicates a suboptimal
condition which should be reported.[1]

Therefore now we shall emit a Warning if a certain
errno occurs a certain number of times[2] as the
outcome of a write to the fuse device.

___
[1] typically ENOENTs and ENOTDIRs accumulate
when glusterfs' inode invalidation lags behind
the kernel's internal inode garbage collection
(in this case above errnos mean that the inode
which we requested to be invalidated is not found
in kernel). This can be mitigated with the
invalidate-limit command line / mount option,
cf. bz#1732717.

[2] 256, as of the current implementation.

Change-Id: I8cc7fe104da43a88875f93b0db49d5677cc16045
Updates: #1000
Signed-off-by: Csaba Henk <csaba@redhat.com>
(cherry picked from commit c1baf3c68b87584aea5389af958326f6ed01d7ec)

Problem:
tests/bugs/protocol/bug-1433815-auth-allow.t fails
sometimes because of stale mount. This stale mount
comes into picture when parent process dies without
waiting for the child process which mounts fuse fs
to die

Fix:
Wait for mounting child process to die before dying.

Fixes: #1152
Change-Id: I8baee8720e88614fdb762ea822d5877973eef8dc
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

Change-Id: Ib07c31dc6669aa9d9f84a21e6160237290ed9afb
Fixes: bz#1804786

Problem:

FUSE uses failures of communicating with /dev/fuse with various
errnos to indicate in-kernel conditions to userspace. Some of these
shouldn't be handled as an application error. Also the standard
POSIX errno description should not be shown as they are misleading
in this context.

Solution:

When writing to the fuse device, the caller of the respective
convenience routine can mask those errnos which don't qualify to
be an error for the application in that context, so then those
shall be reported at DEBUG level.

The possible non-standard errnos are reported with their
POSIX name instead of their description to avoid confusion.
(Eg. for ENOENT we don't log "no such file or directory",
we log indeed literal "ENOENT".)

Change-Id: I510158843e4b1d482bdc496c2e97b1860dc1ba93
updates: bz#1193929
Signed-off-by: Csaba Henk <csaba@redhat.com>

Code like:

f(..., uuid_utoa(x), uuid_utoa(y));

is not valid (causes undefined behaviour) because uuid_utoa()
uses the only static thread-local buffer which will be overwritten
by the subsequent call. All such cases should be converted to use
uuid_utoa_r() with explicitly specified buffer.

Change-Id: I5e72bab806d96a9dd1707c28ed69ca033b9c8d6c
Updates: bz#1193929
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>

updates: bz#1193929
Change-Id: I50f75f730ea6970e99347fcee661ce9dc8477725
Signed-off-by: Xie Changlong <xiechanglong@cmss.chinamobile.com>

Problem:
When touch is used to create a file, the ctime is not matching
atime and mtime which ideally should match. There is a difference
in nano seconds.

Cause:
When touch is used modify atime or mtime to current time (UTIME_NOW),
the current time is taken from kernel. The ctime gets updated to current
time when atime or mtime is updated. But the current time to update
ctime is taken from utime xlator. Hence the difference in nano seconds.

Fix:
When utimesat uses UTIME_NOW, use the current time from kernel.

fixes: bz#1773530
Change-Id: I9ccfa47dcd39df23396852b4216f1773c49250ce
Signed-off-by: Kotresh HR <khiremat@redhat.com>

updates bz#1193929
Signed-off-by: Csaba Henk <csaba@redhat.com>
Change-Id: I12cbe1d87f60fb497654d0e13e12171940867f76