xfs: use current->journal_info for detecting transaction recursion

Source kernel commit: 756b1c343333a5aefcc26b0409f3fd16f72281bf

Because the iomap code using PF_MEMALLOC_NOFS to detect transaction
recursion in XFS is just wrong. Remove it from the iomap code and
replace it with XFS specific internal checks using
current->journal_info instead.

[djwong: This change also realigns the lifetime of NOFS flag changes to
match the incore transaction, instead of the inconsistent scheme we have
now.]

Fixes: 9070733b4efa ("xfs: abstract PF_FSTRANS to PF_MEMALLOC_NOFS")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_btree.c b/libxfs/xfs_btree.c
index d1ac742b50f57ec74059cafec23ac9f053974c61..d52fdc005fe9e1a7eecb7081b455c6ff7b353671 100644 (file)
--- a/libxfs/xfs_btree.c
+++ b/libxfs/xfs_btree.c
@@ -2803,7 +2803,7 @@ xfs_btree_split_worker(
        struct xfs_btree_split_args     *args = container_of(work,
                                                struct xfs_btree_split_args, work);
        unsigned long           pflags;
-       unsigned long           new_pflags = PF_MEMALLOC_NOFS;
+       unsigned long           new_pflags = 0;
 
        /*
         * we are in a transaction context here, but may also be doing work
@@ -2815,12 +2815,20 @@ xfs_btree_split_worker(
                new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
 
        current_set_flags_nested(&pflags, new_pflags);
+       xfs_trans_set_context(args->cur->bc_tp);
 
        args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
                                         args->key, args->curp, args->stat);
-       complete(args->done);
 
+       xfs_trans_clear_context(args->cur->bc_tp);
        current_restore_flags_nested(&pflags, new_pflags);
+
+       /*
+        * Do not access args after complete() has run here. We don't own args
+        * and the owner may run and free args before we return here.
+        */
+       complete(args->done);
+
 }
 
 /*