xfs: don't truncate attribute extents if no extents exist

[firefly-linux-kernel-4.4.55.git] / fs / xfs / xfs_attr_inactive.c

diff --git a/fs/xfs/xfs_attr_inactive.c b/fs/xfs/xfs_attr_inactive.c
index f9c1c64782d39ec36fabf800653772f8c5b24280..73e75a87af5027cc8841a915637eaf661644c4b0 100644 (file)
--- a/fs/xfs/xfs_attr_inactive.c
+++ b/fs/xfs/xfs_attr_inactive.c
@@ -380,23 +380,31 @@ xfs_attr3_root_inactive(
        return error;
 }
 
+/*
+ * xfs_attr_inactive kills all traces of an attribute fork on an inode. It
+ * removes both the on-disk and in-memory inode fork. Note that this also has to
+ * handle the condition of inodes without attributes but with an attribute fork
+ * configured, so we can't use xfs_inode_hasattr() here.
+ *
+ * The in-memory attribute fork is removed even on error.
+ */
 int
-xfs_attr_inactive(xfs_inode_t *dp)
+xfs_attr_inactive(
+       struct xfs_inode        *dp)
 {
-       xfs_trans_t *trans;
-       xfs_mount_t *mp;
-       int error;
+       struct xfs_trans        *trans;
+       struct xfs_mount        *mp;
+       int                     cancel_flags = 0;
+       int                     lock_mode = XFS_ILOCK_SHARED;
+       int                     error = 0;
 
        mp = dp->i_mount;
        ASSERT(! XFS_NOT_DQATTACHED(mp, dp));
 
-       xfs_ilock(dp, XFS_ILOCK_SHARED);
-       if (!xfs_inode_hasattr(dp) ||
-           dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
-               xfs_iunlock(dp, XFS_ILOCK_SHARED);
-               return 0;
-       }
-       xfs_iunlock(dp, XFS_ILOCK_SHARED);
+       xfs_ilock(dp, lock_mode);
+       if (!XFS_IFORK_Q(dp))
+               goto out_destroy_fork;
+       xfs_iunlock(dp, lock_mode);
 
        /*
         * Start our first transaction of the day.
@@ -408,13 +416,18 @@ xfs_attr_inactive(xfs_inode_t *dp)
         * the inode in every transaction to let it float upward through
         * the log.
         */
+       lock_mode = 0;
        trans = xfs_trans_alloc(mp, XFS_TRANS_ATTRINVAL);
        error = xfs_trans_reserve(trans, &M_RES(mp)->tr_attrinval, 0, 0);
-       if (error) {
-               xfs_trans_cancel(trans, 0);
-               return error;
-       }
-       xfs_ilock(dp, XFS_ILOCK_EXCL);
+       if (error)
+               goto out_cancel;
+
+       lock_mode = XFS_ILOCK_EXCL;
+       cancel_flags = XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT;
+       xfs_ilock(dp, lock_mode);
+
+       if (!XFS_IFORK_Q(dp))
+               goto out_cancel;
 
        /*
         * No need to make quota reservations here. We expect to release some
@@ -423,28 +436,36 @@ xfs_attr_inactive(xfs_inode_t *dp)
        xfs_trans_ijoin(trans, dp, 0);
 
        /*
-        * Decide on what work routines to call based on the inode size.
+        * Invalidate and truncate the attribute fork extents. Make sure the
+        * fork actually has attributes as otherwise the invalidation has no
+        * blocks to read and returns an error. In this case, just do the fork
+        * removal below.
         */
-       if (!xfs_inode_hasattr(dp) ||
-           dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
-               error = 0;
-               goto out;
+       if (xfs_inode_hasattr(dp) &&
+           dp->i_d.di_aformat != XFS_DINODE_FMT_LOCAL) {
+               error = xfs_attr3_root_inactive(&trans, dp);
+               if (error)
+                       goto out_cancel;
+
+               error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK, 0);
+               if (error)
+                       goto out_cancel;
        }
-       error = xfs_attr3_root_inactive(&trans, dp);
-       if (error)
-               goto out;
 
-       error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK, 0);
-       if (error)
-               goto out;
+       /* Reset the attribute fork - this also destroys the in-core fork */
+       xfs_attr_fork_remove(dp, trans);
 
        error = xfs_trans_commit(trans, XFS_TRANS_RELEASE_LOG_RES);
-       xfs_iunlock(dp, XFS_ILOCK_EXCL);
-
+       xfs_iunlock(dp, lock_mode);
        return error;
 
-out:
-       xfs_trans_cancel(trans, XFS_TRANS_RELEASE_LOG_RES|XFS_TRANS_ABORT);
-       xfs_iunlock(dp, XFS_ILOCK_EXCL);
+out_cancel:
+       xfs_trans_cancel(trans, cancel_flags);
+out_destroy_fork:
+       /* kill the in-core attr fork before we drop the inode lock */
+       if (dp->i_afp)
+               xfs_idestroy_fork(dp, XFS_ATTR_FORK);
+       if (lock_mode)
+               xfs_iunlock(dp, lock_mode);
        return error;
 }