diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2013-02-07 10:54:07 -0500 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2013-02-11 15:33:13 -0500 |
| commit | 65b62a29f719e937b5be1df472287f4c61e53ac6 (patch) | |
| tree | ea6b552a08883d92cfedb891044fa9697cbc5619 /fs/nfs | |
| parent | 37380e4264dbda9753e470a30d4322097aab7152 (diff) | |
NFSv4: Ensure delegation recall and byte range lock removal don't conflict
Add a mutex to the struct nfs4_state_owner to ensure that delegation
recall doesn't conflict with byte range lock removal.
Note that we nest the new mutex _outside_ the state manager reclaim
protection (nfsi->rwsem) in order to avoid deadlocks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/delegation.c | 7 | ||||
| -rw-r--r-- | fs/nfs/nfs4_fs.h | 1 | ||||
| -rw-r--r-- | fs/nfs/nfs4proc.c | 9 | ||||
| -rw-r--r-- | fs/nfs/nfs4state.c | 1 |
4 files changed, 16 insertions, 2 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 2542cdaa111..6390a4b5fee 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -71,8 +71,10 @@ static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_ int status = 0; if (inode->i_flock == NULL) - goto out; + return 0; + if (inode->i_flock == NULL) + goto out; /* Protect inode->i_flock using the file locks lock */ lock_flocks(); for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { @@ -113,12 +115,15 @@ again: get_nfs_open_context(ctx); spin_unlock(&inode->i_lock); sp = state->owner; + /* Block nfs4_proc_unlck */ + mutex_lock(&sp->so_delegreturn_mutex); seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); err = nfs4_open_delegation_recall(ctx, state, stateid); if (!err) err = nfs_delegation_claim_locks(ctx, state); if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) err = -EAGAIN; + mutex_unlock(&sp->so_delegreturn_mutex); put_nfs_open_context(ctx); if (err != 0) return err; diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index b12b7347202..944c9a5c103 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -93,6 +93,7 @@ struct nfs4_state_owner { struct list_head so_states; struct nfs_seqid_counter so_seqid; seqcount_t so_reclaim_seqcount; + struct mutex so_delegreturn_mutex; }; enum { diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index f7e05ade557..d51227371c6 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4485,7 +4485,9 @@ static struct rpc_task *nfs4_do_unlck(struct file_lock *fl, static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request) { - struct nfs_inode *nfsi = NFS_I(state->inode); + struct inode *inode = state->inode; + struct nfs4_state_owner *sp = state->owner; + struct nfs_inode *nfsi = NFS_I(inode); struct nfs_seqid *seqid; struct nfs4_lock_state *lsp; struct rpc_task *task; @@ -4495,12 +4497,17 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock * status = nfs4_set_lock_state(state, request); /* Unlock _before_ we do the RPC call */ request->fl_flags |= FL_EXISTS; + /* Exclude nfs_delegation_claim_locks() */ + mutex_lock(&sp->so_delegreturn_mutex); + /* Exclude nfs4_reclaim_open_stateid() - note nesting! */ down_read(&nfsi->rwsem); if (do_vfs_lock(request->fl_file, request) == -ENOENT) { up_read(&nfsi->rwsem); + mutex_unlock(&sp->so_delegreturn_mutex); goto out; } up_read(&nfsi->rwsem); + mutex_unlock(&sp->so_delegreturn_mutex); if (status != 0) goto out; /* Is this a delegated lock? */ diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index fff97228cde..6ace365c633 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -519,6 +519,7 @@ nfs4_alloc_state_owner(struct nfs_server *server, atomic_set(&sp->so_count, 1); INIT_LIST_HEAD(&sp->so_lru); seqcount_init(&sp->so_reclaim_seqcount); + mutex_init(&sp->so_delegreturn_mutex); return sp; } |