evin/ms-nfs41-client
3
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

pnfs: new locking model for layouts

Browse source 
exclusive locks are no longer held over LAYOUTGET, LAYOUTRETURN, or GETDEVICEINFO rpcs.  this prevents a deadlock when CB_LAYOUTRECALL needs an exclusive lock while another operation is on the wire

introduced a 'pending' condition variable to protect access to state->layout while the layout's lock is not held

updated file_layout_recall() to compare the stateid sequence numbers to determine if the server has processed an outstanding LAYOUTGET or LAYOUTRETURN, where we're required to reply with NFS4ERR_DELAY

LAYOUTGET, LAYOUTRETURN, and GETDEVICEINFO can now be sent with try_recovery=TRUE because they no longer hold an exclusive lock.  this makes it possible for recover_client_state() to recall all of the client's layouts without deadlocking

Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
This commit is contained in:
Casey Bodley 2011-03-10 12:46:34 -05:00 • committed by unknown
parent c9585d937f
commit bf53e3dc1a
4 changed files with 77 additions and 24 deletions
Download patch file Download diff file Expand all files Collapse all files

2
daemon/pnfs.h
View file

@ -164,7 +164,9 @@ typedef struct __pnfs_layout_state {
bool_t return_on_close;
LONG open_count; /* for return on last close */
uint32_t io_count; /* number of pending io operations */
bool_t pending; /* pending LAYOUTGET/LAYOUTRETURN */
SRWLOCK lock;
CONDITION_VARIABLE cond;
} pnfs_layout_state;
typedef struct __pnfs_layout {