Merge tag 'nfs-for-3.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "New features include:
   - Rewrite the O_DIRECT code so that it can share the same coalescing
     and pNFS functionality as the page cache code.
   - Allow the server to provide hints as to when we should use pNFS,
     and when it is more efficient to read and write through the
     metadata server.
   - NFS cache consistency updates:
     * Use the ctime to emulate a change attribute for NFSv2/v3 so that
       all NFS versions can share the same cache management code.
     * New cache management code will only look at the change attribute
       and size attribute when deciding whether or not our cached data
       is still valid or not.
     * Don't request NFSv4 post-op attributes on writes in cases such as
       O_DIRECT, where we don't care about data cache consistency, or
       when we have a write delegation, and know that our cache is still
       consistent.
     * Don't request NFSv4 post-op attributes on operations such as
       COMMIT, where there are no expected metadata updates.
     * Don't request NFSv4 directory post-op attributes in cases where
       the operations themselves already return change attribute
       updates: i.e. operations such as OPEN, CREATE, REMOVE, LINK and
       RENAME.
   - Speed up 'ls' and friends by using READDIR rather than READDIRPLUS
     if we detect no attempts to lookup filenames.
   - Improve the code sharing between NFSv2/v3 and v4 mounts
   - NFSv4.1 state management efficiency improvements
   - More patches in preparation for NFSv4/v4.1 migration functionality."

Fix trivial conflict in fs/nfs/nfs4proc.c that was due to the dcache
qstr name initialization changes (that made the length/hash a 64-bit
union)

* tag 'nfs-for-3.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (146 commits)
  NFSv4: Add debugging printks to state manager
  NFSv4: Map NFS4ERR_SHARE_DENIED into an EACCES error instead of EIO
  NFSv4: update_changeattr does not need to set NFS_INO_REVAL_PAGECACHE
  NFSv4.1: nfs4_reset_session should use nfs4_handle_reclaim_lease_error
  NFSv4.1: Handle other occurrences of NFS4ERR_CONN_NOT_BOUND_TO_SESSION
  NFSv4.1: Handle NFS4ERR_CONN_NOT_BOUND_TO_SESSION in the state manager
  NFSv4.1: Handle errors in nfs4_bind_conn_to_session
  NFSv4.1: nfs4_bind_conn_to_session should drain the session
  NFSv4.1: Don't clobber the seqid if exchange_id returns a confirmed clientid
  NFSv4.1: Add DESTROY_CLIENTID
  NFSv4.1: Ensure we use the correct credentials for bind_conn_to_session
  NFSv4.1: Ensure we use the correct credentials for session create/destroy
  NFSv4.1: Move NFSPROC4_CLNT_BIND_CONN_TO_SESSION to the end of the operations
  NFSv4.1: Handle NFS4ERR_SEQ_MISORDERED when confirming the lease
  NFSv4: When purging the lease, we must clear NFS4CLNT_LEASE_CONFIRM
  NFSv4: Clean up the error handling for nfs4_reclaim_lease
  NFSv4.1: Exchange ID must use GFP_NOFS allocation mode
  nfs41: Use BIND_CONN_TO_SESSION for CB_PATH_DOWN*
  nfs4.1: add BIND_CONN_TO_SESSION operation
  NFSv4.1 test the mdsthreshold hint parameters
  ...

1 files changed, 12 insertions, 4 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 89af1d269274..bd3a9601d32d 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -316,6 +316,10 @@ out:
  * nfs_client_return_marked_delegations - return previously marked delegations
  * @clp: nfs_client to process
  *
+ * Note that this function is designed to be called by the state
+ * manager thread. For this reason, it cannot flush the dirty data,
+ * since that could deadlock in case of a state recovery error.
+ *
  * Returns zero on success, or a negative errno value.
  */
 int nfs_client_return_marked_delegations(struct nfs_client *clp)
@@ -340,11 +344,9 @@ restart:
                                                                 server);
                         rcu_read_unlock();
 
-                        if (delegation != NULL) {
-                                filemap_flush(inode->i_mapping);
+                        if (delegation != NULL)
                                 err = __nfs_inode_return_delegation(inode,
                                                                 delegation, 0);
-                        }
                         iput(inode);
                         if (!err)
                                 goto restart;
@@ -380,6 +382,10 @@ void nfs_inode_return_delegation_noreclaim(struct inode *inode)
  * nfs_inode_return_delegation - synchronously return a delegation
  * @inode: inode to process
  *
+ * This routine will always flush any dirty data to disk on the
+ * assumption that if we need to return the delegation, then
+ * we should stop caching.
+ *
  * Returns zero on success, or a negative errno value.
  */
 int nfs_inode_return_delegation(struct inode *inode)
@@ -389,10 +395,10 @@ int nfs_inode_return_delegation(struct inode *inode)
         struct nfs_delegation *delegation;
         int err = 0;
 
+        nfs_wb_all(inode);
         if (rcu_access_pointer(nfsi->delegation) != NULL) {
                 delegation = nfs_detach_delegation(nfsi, server);
                 if (delegation != NULL) {
-                        nfs_wb_all(inode);
                         err = __nfs_inode_return_delegation(inode, delegation, 1);
                 }
         }
@@ -538,6 +544,8 @@ int nfs_async_inode_return_delegation(struct inode *inode,
         struct nfs_client *clp = server->nfs_client;
         struct nfs_delegation *delegation;
 
+        filemap_flush(inode->i_mapping);
+
         rcu_read_lock();
         delegation = rcu_dereference(NFS_I(inode)->delegation);