glusterd: Add multiple checks before attach/start a brick

2018-07-27T01:24:09+00:00

Problem: In brick mux scenario sometime glusterd is not able
         to start/attach a brick and gluster v status shows
         brick is already running

Solution:
          1) To make sure brick is running check brick_path in
             /proc//fd , if a brick is consumed by the brick
             process it means brick stack is come up otherwise not
          2) Before start/attach a brick check if a brick is mounted
             or not
          3) At the time of printing volume status check brick is
             consumed by any brick process

Test:  To test the same followed procedure
       1) Setup brick mux environment on a vm
       2) Put a breaking point in gdb in function posix_health_check_thread_proc
          at the time of notify GF_EVENT_CHILD_DOWN event
       3) unmount anyone brick path forcefully
       4) check gluster v status it will show N/A for the brick
       5) Try to start volume with force option, glusterd throw
          message "No device available for mount brick"
       6) Mount the brick_root path
       7) Try to start volume with force option
       8) down brick is started successfully

Change-Id: I91898dad21d082ebddd12aa0d1f7f0ed012bdf69
fixes: bz#1595320
Signed-off-by: Mohit Agrawal

posix: option to handle the shared bricks for statvfs()

2017-07-24T15:34:34+00:00

Currently 'storage/posix' xlator has an option called option
`export-statfs-size no`, which exports zero as values for few
fields in `struct statvfs`. In a case of backend brick shared
between multiple brick processes, the values of these variables
should be `field_value / number-of-bricks-at-node`. This way,
even the issue of 'min-free-disk' etc at different layers would
also be handled properly when the statfs() sys call is made.

Fixes #241

Change-Id: I2e320e1fdcc819ab9173277ef3498201432c275f
Signed-off-by: Amar Tumballi 
Reviewed-on: https://review.gluster.org/17618
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System 
Reviewed-by: Jeff Darcy 
Reviewed-by: Atin Mukherjee

glusterfs.git/tests/basic/posix/shared-statfs.t, branch v7.1

glusterd: Add multiple checks before attach/start a brick

posix: option to handle the shared bricks for statvfs()