[XFS] Wait for all async buffers to complete before tearing down the

filesystem at umount time

SGI-PV: 901236
SGI-Modid: xfs-linux:xfs-kern:182694a
Signed-off-by: Eric Sandeen <sandeen@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/linux-2.6/xfs_buf.c

@@ -1468,6 +1468,34 @@ pagebuf_iomove(
  *	Handling of buftargs.
  */
 
+/*
+ * Wait for any bufs with callbacks that have been submitted but
+ * have not yet returned... walk the hash list for the target.
+ */
+void
+xfs_wait_buftarg(
+	xfs_buftarg_t *target)
+{
+	xfs_buf_t	*pb, *n;
+	pb_hash_t	*h;
+	int		i;
+
+	for (i = 0; i < NHASH; i++) {
+		h = &pbhash[i];
+again:
+		spin_lock(&h->pb_hash_lock);
+		list_for_each_entry_safe(pb, n, &h->pb_hash, pb_hash_list) {
+			if (pb->pb_target == target &&
+					!(pb->pb_flags & PBF_FS_MANAGED)) {
+				spin_unlock(&h->pb_hash_lock);
+				delay(100);
+				goto again;
+			}
+		}
+		spin_unlock(&h->pb_hash_lock);
+	}
+}
+
 void
 xfs_free_buftarg(
 	xfs_buftarg_t		*btp,

fs/xfs/linux-2.6/xfs_buf.h

@@ -566,6 +566,7 @@ static inline int xfs_bdwrite(void *mp, xfs_buf_t *bp)
 
 extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *);
 extern void xfs_free_buftarg(xfs_buftarg_t *, int);
+extern void xfs_wait_buftarg(xfs_buftarg_t *);
 extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
 extern void xfs_incore_relse(xfs_buftarg_t *, int, int);
 extern int xfs_flush_buftarg(xfs_buftarg_t *, int);

fs/xfs/xfs_mount.c

@@ -1098,6 +1098,8 @@ xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
 
 	xfs_unmountfs_writesb(mp);
 
+	xfs_unmountfs_wait(mp); 		/* wait for async bufs */
+
 	xfs_log_unmount(mp);			/* Done! No more fs ops. */
 
 	xfs_freesb(mp);
@@ -1142,6 +1144,16 @@ xfs_unmountfs_close(xfs_mount_t *mp, struct cred *cr)
 	xfs_free_buftarg(mp->m_ddev_targp, 0);
 }
 
+void
+xfs_unmountfs_wait(xfs_mount_t *mp)
+{
+	if (mp->m_logdev_targp != mp->m_ddev_targp)
+		xfs_wait_buftarg(mp->m_logdev_targp);
+	if (mp->m_rtdev_targp)
+		xfs_wait_buftarg(mp->m_rtdev_targp);
+	xfs_wait_buftarg(mp->m_ddev_targp);
+}
+
 int
 xfs_unmountfs_writesb(xfs_mount_t *mp)
 {

fs/xfs/xfs_mount.h

@@ -541,6 +541,7 @@ extern void	xfs_mount_free(xfs_mount_t *mp, int remove_bhv);
 extern int	xfs_mountfs(struct vfs *, xfs_mount_t *mp, int);
 
 extern int	xfs_unmountfs(xfs_mount_t *, struct cred *);
+extern void	xfs_unmountfs_wait(xfs_mount_t *);
 extern void	xfs_unmountfs_close(xfs_mount_t *, struct cred *);
 extern int	xfs_unmountfs_writesb(xfs_mount_t *);
 extern int	xfs_unmount_flush(xfs_mount_t *, int);