Commit 550f5747 authored Oct 18, 2005 by Trond Myklebust

NFSv4: Ensure that we recover from the OPEN + OPEN_CONFIRM BAD_STATEID race



 If the server is in the unconfirmed OPEN state for a given open owner
 and receives a second OPEN for the same open owner, it will cancel the
 state of the first request and set up an OPEN_CONFIRM for the second.

 This can cause a race that is discussed in rfc3530 on page 181.

 The following patch allows the client to recover by retrying the
 original open request.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

parent b8e5c4c2

fs/nfs/nfs4proc.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -785,6 +785,16 @@ static struct nfs4_state nfs4_do_open(struct inode dir, struct dentry *dentry,
		exception.retry = 1;
		continue;
		}
		/*
		* BAD_STATEID on OPEN means that the server cancelled our
		* state before it received the OPEN_CONFIRM.
		* Recover by retrying the request as per the discussion
		* on Page 181 of RFC3530.
		*/
		if (status == -NFS4ERR_BAD_STATEID) {
		exception.retry = 1;
		continue;
		}
		res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(dir),
		status, &exception));
		} while (exception.retry);