zfs/module
Brian Behlendorf 71c9f0b003 Make kstat.ks_update() callback atomic
Move the kstat ks_update() callback under the ks_lock.  This
enables dynamically sized kstats without modification to the
kstat API.

  * Create a kstat with the KSTAT_FLAG_VIRTUAL flag.
  * Register a ->ks_update() callback which does:
    o Frees any existing ks_data buffer.
    o Set ks_data_size to the kstat array size.
    o Set ks_data to an allocated buffer of size ks_data_size
    o Populate the array of buffers with the required data.

The buffer allocated in the ks_update() callback is guaranteed
to remain allocated and valid while the proc sequence handler
iterates over the buffer.  The lock will not be dropped until
kstat_seq_stop() function is run making it safe for concurrent
access.  To allow the ks_update() callback to perform memory
allocations the lock was changed to a mutex.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-10-23 09:36:19 -07:00
..
spl Make kstat.ks_update() callback atomic 2012-10-23 09:36:19 -07:00
splat Linux 3.7 compat, __clear_close_on_exec() removed 2012-10-18 13:36:44 -07:00
.gitignore Remove Makefile from non-toplevel .gitignore files 2012-08-23 12:49:04 -07:00
Makefile.in Add script for builtin module building. 2012-07-26 15:13:09 -07:00