linux-stable.git/fs/nfs/callback_proc.c, branch linux-3.10.y

NFSv4.1 Fix a pNFS session draining deadlock

2013-05-20T18:20:14+00:00

On a CB_RECALL the callback service thread flushes the inode using
filemap_flush prior to scheduling the state manager thread to return the
delegation. When pNFS is used and I/O has not yet gone to the data server
servicing the inode, a LAYOUTGET can preceed the I/O. Unlike the async
filemap_flush call, the LAYOUTGET must proceed to completion.

If the state manager starts to recover data while the inode flush is sending
the LAYOUTGET, a deadlock occurs as the callback service thread holds the
single callback session slot until the flushing is done which blocks the state
manager thread, and the state manager thread has set the session draining bit
which puts the inode flush LAYOUTGET RPC to sleep on the forechannel slot
table waitq.

Separate the draining of the back channel from the draining of the fore channel
by moving the NFS4_SESSION_DRAINING bit from session scope into the fore
and back slot tables.  Drain the back channel first allowing the LAYOUTGET
call to proceed (and fail) so the callback service thread frees the callback
slot. Then proceed with draining the forechannel.

Signed-off-by: Andy Adamson 
Signed-off-by: Trond Myklebust

NFSv4: Fix CB_RECALL_ANY to only return delegations that are not in use

2013-04-05T21:03:57+00:00

Signed-off-by: Trond Myklebust

NFSv4.1: Fix bulk recall and destroy of layouts

2013-02-14T18:22:50+00:00

The current code in pnfs_destroy_all_layouts() assumes that removing
the layout from the server->layouts list is sufficient to make it
invisible to other processes. This ignores the fact that most
users access the layout through the nfs_inode->layout...
There is further breakage due to lack of reference counting of the
layouts, meaning that the whole thing Oopses at the drop of a hat.

The code in initiate_bulk_draining() is almost correct, and can be
used as a model for pnfs_destroy_all_layouts(), so move that
code to pnfs.c, and refactor the code to allow us to choose between
a single filesystem bulk recall, and a recall of all layouts.
Also note that initiate_bulk_draining() currently calls iput() while
holding locks. Fix that too.

Signed-off-by: Trond Myklebust 
Cc: stable@vger.kernel.org

nfs: avoid dereferencing null pointer in initiate_bulk_draining

2013-01-05T19:26:51+00:00

Fix an inverted null pointer check in initiate_bulk_draining().

Signed-off-by: Nickolai Zeldovich 
Signed-off-by: Trond Myklebust 
Cc: stable@vger.kernel.org [>= 3.7]

NFSv4.1: Cleanup move session slot management to fs/nfs/nfs4session.c

2012-12-05T23:30:45+00:00

NFSv4.1 session management is getting complex enough to deserve
a separate file.

Signed-off-by: Trond Myklebust

NFSv4.1: CB_RECALL_SLOT must schedule a sequence op after updating targets

2012-12-05T23:30:43+00:00

RFC5661 requires us to make sure that the server knows we've updated
our slot table size by sending at least one SEQUENCE op containing the
new 'highest_slotid' value.
We can do so using the 'CHECK_LEASE' functionality of the state
manager.

Signed-off-by: Trond Myklebust

NFSv4.1: Remove the state manager code to resize the slot table

2012-12-05T23:30:43+00:00

The state manager no longer needs any special machinery to stop the
session flow and resize the slot table. It is all done on the fly by
the SEQUENCE op code now.

Signed-off-by: Trond Myklebust

NFSv4.1: Allow the server to recall all but one slot

2012-12-05T23:30:42+00:00

If the server wants to leave us with only one slot, or it wants
to "shrink" our slot table to something larger than we have now,
then so be it.

Signed-off-by: Trond Myklebust

NFSv4.1: Don't confuse target_highest_slotid and max_slots in cb_recall_slot

2012-12-05T23:30:41+00:00

Don't confuse the table size and the target_highest_slotid...

Signed-off-by: Trond Myklebust

NFSv4.1: Fix nfs4_callback_recallslot to work with dynamic slot allocation

2012-12-05T23:30:37+00:00

Ensure that the NFSv4.1 CB_RECALL_SLOT callback updates the slot table
target max slotid safely.

Signed-off-by: Trond Myklebust