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  1. 30 7月, 2014 12 次提交
  3. 24 7月, 2014 7 次提交
  5. 23 7月, 2014 2 次提交
    • C
      svcrdma: Add zero padding if the client doesn't send it · e560e3b5
      由 Chuck Lever 提交于 
      See RFC 5666 section 3.7: clients don't have to send zero XDR
padding.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=246Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      e560e3b5
    • J
      nfsd: bump dl_time when unhashing delegation · d55a166c
      由 Jeff Layton 提交于 
      There's a potential race between a lease break and DELEGRETURN call.

Suppose a lease break comes in and queues the workqueue job for a
delegation, but it doesn't run just yet. Then, a DELEGRETURN comes in
finds the delegation and calls destroy_delegation on it to unhash it and
put its primary reference.

Next, the workqueue job runs and queues the delegation back onto the
del_recall_lru list, issues the CB_RECALL and puts the final reference.
With that, the final reference to the delegation is put, but it's still
on the LRU list.

When we go to unhash a delegation, it's because we intend to get rid of
it soon afterward, so we don't want lease breaks to mess with it once
that occurs. Fix this by bumping the dl_time whenever we unhash a
delegation, to ensure that lease breaks don't monkey with it.

I believe this is a regression due to commit 02e1215f (nfsd: Avoid
taking state_lock while holding inode lock in nfsd_break_one_deleg).
Prior to that, the state_lock was held in the lm_break callback itself,
and that would have prevented this race.

Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      d55a166c
  7. 22 7月, 2014 3 次提交
  9. 18 7月, 2014 4 次提交
  11. 17 7月, 2014 4 次提交
  13. 12 7月, 2014 3 次提交
  15. 11 7月, 2014 5 次提交
    • J
      nfsd: cleanup and rename nfs4_check_open · a46cb7f2
      由 Jeff Layton 提交于 
      Rename it to better describe what it does, and have it just return the
stateid instead of a __be32 (which is now always nfs_ok). Also, do the
search for an existing stateid after the delegation check, to reduce
cleanup if the delegation check returns error.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      a46cb7f2
    • J
      nfsd: make deny mode enforcement more efficient and close races in it · baeb4ff0
      由 Jeff Layton 提交于 
      The current enforcement of deny modes is both inefficient and scattered
across several places, which makes it hard to guarantee atomicity. The
inefficiency is a problem now, and the lack of atomicity will mean races
once the client_mutex is removed.

First, we address the inefficiency. We have to track deny modes on a
per-stateid basis to ensure that open downgrades are sane, but when the
server goes to enforce them it has to walk the entire list of stateids
and check against each one.

Instead of doing that, maintain a per-nfs4_file deny mode. When a file
is opened, we simply set any deny bits in that mode that were specified
in the OPEN call. We can then use that unified deny mode to do a simple
check to see whether there are any conflicts without needing to walk the
entire stateid list.

The only time we'll need to walk the entire list of stateids is when a
stateid that has a deny mode on it is being released, or one is having
its deny mode downgraded. In that case, we must walk the entire list and
recalculate the fi_share_deny field. Since deny modes are pretty rare
today, this should be very rare under normal workloads.

To address the potential for races once the client_mutex is removed,
protect fi_share_deny with the fi_lock. In nfs4_get_vfs_file, check to
make sure that any deny mode we want to apply won't conflict with
existing access. If that's ok, then have nfs4_file_get_access check that
new access to the file won't conflict with existing deny modes.

If that also passes, then get file access references, set the correct
access and deny bits in the stateid, and update the fi_share_deny field.
If opening the file or truncating it fails, then unwind the whole mess
and return the appropriate error.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      baeb4ff0
    • J
      nfsd: always hold the fi_lock when bumping fi_access refcounts · 7214e860
      由 Jeff Layton 提交于 
      Once we remove the client_mutex, there's an unlikely but possible race
that could occur. It will be possible for nfs4_file_put_access to race
with nfs4_file_get_access. The refcount will go to zero (briefly) and
then bumped back to one. If that happens we set ourselves up for a
use-after-free and the potential for a lock to race onto the i_flock
list as a filp is being torn down.

Ensure that we can safely bump the refcount on the file by holding the
fi_lock whenever that's done. The only place it currently isn't is in
get_lock_access.

In order to ensure atomicity with finding the file, use the
find_*_file_locked variants and then call get_lock_access to get new
access references on the nfs4_file under the same lock.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      7214e860
    • J
      nfsd: clean up reset_union_bmap_deny · 3b84240a
      由 Jeff Layton 提交于 
      Fix the "deny" argument type, and start the loop at 1. The 0 iteration
is always a noop.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      3b84240a
    • J
      nfsd: set stateid access and deny bits in nfs4_get_vfs_file · 6eb3a1d0
      由 Jeff Layton 提交于 
      Cleanup -- ensure that the stateid bits are set at the same time that
the file access refcounts are incremented. Keeping them coherent like
this makes it easier to ensure that we account for all of the
references.

Since the initialization of the st_*_bmap fields is done when it's
hashed, we go ahead and hash the stateid before getting access to the
file and unhash it if that function returns error. This will be
necessary anyway in a follow-on patch that will overhaul deny mode
handling.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      6eb3a1d0