[XFS] Quota inode has no parent.

Avoid using a special "zero inode" as the parent of the quota inode as
this can confuse the filestreams code into thinking the quota inode has a
parent. We do not want the quota inode to follow filestreams allocation
rules, so pass a NULL as the parent inode and detect this condition when
doing stream associations.

SGI-PV: 964469
SGI-Modid: xfs-linux-melb:xfs-kern:29098a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

2 files changed, 10 insertions, 6 deletions

diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index eeb3d9cc0e8e..7def4c699343 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -65,7 +65,6 @@ kmem_zone_t	*qm_dqtrxzone;
 static struct shrinker *xfs_qm_shaker;
 
 static cred_t   xfs_zerocr;
-static xfs_inode_t      xfs_zeroino;
 
 STATIC void     xfs_qm_list_init(xfs_dqlist_t *, char *, int);
 STATIC void     xfs_qm_list_destroy(xfs_dqlist_t *);
@@ -1415,7 +1414,7 @@ xfs_qm_qino_alloc(
                 return error;
         }
 
-        if ((error = xfs_dir_ialloc(&tp, &xfs_zeroino, S_IFREG, 1, 0,
+        if ((error = xfs_dir_ialloc(&tp, NULL, S_IFREG, 1, 0,
                                    &xfs_zerocr, 0, 1, ip, &committed))) {
                 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
                                  XFS_TRANS_ABORT);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 2ef100be6c4f..59829523ab07 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1078,6 +1078,11 @@ xfs_iread_extents(
  * also returns the [locked] bp pointing to the head of the freelist
  * as ialloc_context.  The caller should hold this buffer across
  * the commit and pass it back into this routine on the second call.
+ *
+ * If we are allocating quota inodes, we do not have a parent inode
+ * to attach to or associate with (i.e. pip == NULL) because they
+ * are not linked into the directory structure - they are attached
+ * directly to the superblock - and so have no parent.
  */
 int
 xfs_ialloc(
@@ -1103,7 +1108,7 @@ xfs_ialloc(
          * Call the space management code to pick
          * the on-disk inode to be allocated.
          */
-        error = xfs_dialloc(tp, pip->i_ino, mode, okalloc,
+        error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode, okalloc,
                             ialloc_context, call_again, &ino);
         if (error != 0) {
                 return error;
@@ -1157,7 +1162,7 @@ xfs_ialloc(
         if ((prid != 0) && (ip->i_d.di_version == XFS_DINODE_VERSION_1))
                 xfs_bump_ino_vers2(tp, ip);
 
-        if (XFS_INHERIT_GID(pip, vp->v_vfsp)) {
+        if (pip && XFS_INHERIT_GID(pip, vp->v_vfsp)) {
                 ip->i_d.di_gid = pip->i_d.di_gid;
                 if ((pip->i_d.di_mode & S_ISGID) && (mode & S_IFMT) == S_IFDIR) {
                         ip->i_d.di_mode |= S_ISGID;
@@ -1199,7 +1204,7 @@ xfs_ialloc(
                 flags |= XFS_ILOG_DEV;
                 break;
         case S_IFREG:
-                if (xfs_inode_is_filestream(pip)) {
+                if (pip && xfs_inode_is_filestream(pip)) {
                         error = xfs_filestream_associate(pip, ip);
                         if (error < 0)
                                 return -error;
@@ -1208,7 +1213,7 @@ xfs_ialloc(
                 }
                 /* fall through */
         case S_IFDIR:
-                if (pip->i_d.di_flags & XFS_DIFLAG_ANY) {
+                if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
                         uint    di_flags = 0;
 
                         if ((mode & S_IFMT) == S_IFDIR) {