[PATCH v3 0/3] nbd: resolve bugs and limitations

[Pranay Kr. Srivastava]

This patch series fixes the following

1) fix might_sleep warning on socket shutdown:
   Fix sock_shutdown to avoid calling kernel_sock_shutdown
   while holding spin_lock.

2) cleanup nbd_set_socket
   Simple fixes to nbd_set_socket.

3) make nbd device wait for its users.
   When a timeout or error occurs then nbd driver simply kills
   the block device. Many filesystem(s) example ext2/ext3 don't
   expect their buffer heads to disappear like that. Fix this
   by making nbd device wait for its users.

   The same work function is used to trigger the kill_bdev as well
   do a sock_shutdown, depending on either a timeout/error occured
   or a disconnect was issued.

   Also avoid scheduling the work_fn in case a timeout for a request
   has already occured.


Pranay Kr. Srivastava (3):
  fix might_sleep warning on socket shutdown
  cleanup nbd_set_socket
  make nbd device wait for its users

 drivers/block/nbd.c | 169 +++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 127 insertions(+), 42 deletions(-)

Changelog:

Rebased all patches above on git://git.pengutronix.de/git/mpa/linux-nbd.git,
commit:7ed71a8704eda7b75fbd0ed73fd0a5b6e469d250

3) make nbd device wait for its users.
   Instead of using kref_sub just use kref_init and under the bd_mutex for
   serializing on open/close.
-- 
1.9.1