fuse: occasional logging for fuse device 'weird' write errors

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>

0 files changed, 0 insertions, 0 deletions