Commit b840be2f authored by J. Bruce Fields's avatar J. Bruce Fields Committed by Chuck Lever
Browse files

lockd: don't attempt blocking locks on nfs reexports 



As in the v4 case, it doesn't work well to block waiting for a lock on
an nfs filesystem.

As in the v4 case, that means we're depending on the client to poll.
It's probably incorrect to depend on that, but I *think* clients do poll
in practice.  In any case, it's an improvement over hanging the lockd
thread indefinitely as we currently are.

Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
Acked-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent f657f8ee

fs/lockd/svclock.c

+10 −3
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/lockd/nlm.h>

#include <linux/lockd/lockd.h>

#include <linux/kthread.h>

#include <linux/exportfs.h>



#define NLMDBG_FACILITY		NLMDBG_SVCLOCK
@@ -470,18 +471,24 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, 
	    struct nlm_cookie *cookie, int reclaim)

{

	struct nlm_block	*block = NULL;

	struct inode		*inode = nlmsvc_file_inode(file);

	int			error;

	int			mode;

	int			async_block = 0;

	__be32			ret;



	dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n",

				nlmsvc_file_inode(file)->i_sb->s_id,

				nlmsvc_file_inode(file)->i_ino,

				inode->i_sb->s_id, inode->i_ino,

				lock->fl.fl_type, lock->fl.fl_pid,

				(long long)lock->fl.fl_start,

				(long long)lock->fl.fl_end,

				wait);



	if (inode->i_sb->s_export_op->flags & EXPORT_OP_SYNC_LOCKS) {

		async_block = wait;

		wait = 0;

	}



	/* Lock file against concurrent access */

	mutex_lock(&file->f_mutex);

	/* Get existing block (in case client is busy-waiting)
@@ -542,7 +549,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, 
			 */

			if (wait)

				break;

			ret = nlm_lck_denied;

			ret = async_block ? nlm_lck_blocked : nlm_lck_denied;

			goto out;

		case FILE_LOCK_DEFERRED:

			if (wait)