Merge tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw into next

Pull gfs2 updates from Steven Whitehouse:
 "This must be about the smallest merge window patch set ever for GFS2.
  It is probably also the first one without a single patch from me.
  That is down to a combination of factors, and I have some things in
  the works that are not quite ready yet, that I hope to put in next
  time around.

  Returning to what is here this time...  we have 3 patches which fix
  various warnings.  Two are bug fixes (for quotas and also a rare
  recovery race condition).  The final patch, from Ben Marzinski, is an
  important change in the freeze code which has been in progress for
  some time.  This removes the need to take and drop the transaction
  lock for every single transaction, when the only time it was used, was
  at file system freeze time.  Ben's patch integrates the freeze
  operation into the journal flush code as an alternative with lower
  overheads and also lands up resolving some difficult to fix races at
  the same time"

* tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: Prevent recovery before the local journal is set
  GFS2: fs/gfs2/file.c: kernel-doc warning fixes
  GFS2: fs/gfs2/bmap.c: kernel-doc warning fixes
  GFS2: remove transaction glock
  GFS2: lops.c: replace 0 by NULL for pointers
  GFS2: quotas not being refreshed in gfs2_adjust_quota

1 files changed, 30 insertions, 10 deletions

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 28cc7bf6575a..e62e59477884 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1613,18 +1613,26 @@ int gfs2_permission(struct inode *inode, int mask)
 {
 	struct gfs2_inode *ip;
 	struct gfs2_holder i_gh;
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	int error;
 	int unlock = 0;
+	int frozen_root = 0;
 
 
 	ip = GFS2_I(inode);
 	if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {
-		if (mask & MAY_NOT_BLOCK)
-			return -ECHILD;
-		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
-		if (error)
-			return error;
-		unlock = 1;
+		if (unlikely(gfs2_glock_is_held_excl(sdp->sd_freeze_gl) &&
+			     inode == sdp->sd_root_dir->d_inode &&
+			     atomic_inc_not_zero(&sdp->sd_frozen_root)))
+			frozen_root = 1;
+		else {
+			if (mask & MAY_NOT_BLOCK)
+				return -ECHILD;
+			error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
+			if (error)
+				return error;
+			unlock = 1;
+		}
 	}
 
 	if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
@@ -1633,6 +1641,8 @@ int gfs2_permission(struct inode *inode, int mask)
 		error = generic_permission(inode, mask);
 	if (unlock)
 		gfs2_glock_dq_uninit(&i_gh);
+	else if (frozen_root && atomic_dec_and_test(&sdp->sd_frozen_root))
+		wake_up(&sdp->sd_frozen_root_wait);
 
 	return error;
 }
@@ -1805,19 +1815,29 @@ static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
 	struct inode *inode = dentry->d_inode;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_holder gh;
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	int error;
 	int unlock = 0;
+	int frozen_root = 0;
 
 	if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {
-		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
-		if (error)
-			return error;
-		unlock = 1;
+		if (unlikely(gfs2_glock_is_held_excl(sdp->sd_freeze_gl) &&
+			     inode == sdp->sd_root_dir->d_inode &&
+			     atomic_inc_not_zero(&sdp->sd_frozen_root)))
+			frozen_root = 1;
+		else {
+			error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
+			if (error)
+				return error;
+			unlock = 1;
+		}
 	}
 
 	generic_fillattr(inode, stat);
 	if (unlock)
 		gfs2_glock_dq_uninit(&gh);
+	else if (frozen_root && atomic_dec_and_test(&sdp->sd_frozen_root))
+		wake_up(&sdp->sd_frozen_root_wait);
 
 	return 0;
 }