xfs: actually rebuild the parent pointer xattrs

Once we've assembled all the parent pointers for a file, we need to
commit the new dataset atomically to that file.  Parent pointer records
are embedded in the xattr structure, which means that we must write a
new extended attribute structure, again, atomically.  Therefore, we must
copy the non-parent-pointer attributes from the file being repaired into
the temporary file's extended attributes and then call the atomic extent
swap mechanism to exchange the blocks.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_attr.c

@@ -948,7 +948,7 @@ xfs_attr_lookup(
 	return error;
 }
 
-STATIC int
+int
 xfs_attr_add_fork(
 	struct xfs_inode	*ip,		/* incore inode pointer */
 	int			size,		/* space new attribute needs */

fs/xfs/libxfs/xfs_attr.h

@@ -648,5 +648,6 @@ int __init xfs_attr_intent_init_cache(void);
 void xfs_attr_intent_destroy_cache(void);
 
 int xfs_attr_sf_totsize(struct xfs_inode *dp);
+int xfs_attr_add_fork(struct xfs_inode *ip, int size, int rsvd);
 
 #endif	/* __XFS_ATTR_H__ */

fs/xfs/scrub/attr_repair.c

@@ -1030,7 +1030,7 @@ xrep_xattr_reset_fork(
  * fork.  The caller must ILOCK the tempfile and join it to the transaction.
  * This function returns with the inode joined to a clean scrub transaction.
  */
-STATIC int
+int
 xrep_xattr_reset_tempfile_fork(
 	struct xfs_scrub	*sc)
 {
@@ -1336,7 +1336,7 @@ xrep_xattr_swap_prep(
 }
 
 /* Exchange the temporary file's attribute fork with the one being repaired. */
-STATIC int
+int
 xrep_xattr_swap(
 	struct xfs_scrub	*sc,
 	struct xrep_tempexch	*tx)

fs/xfs/scrub/attr_repair.h

@@ -6,6 +6,10 @@
 #ifndef __XFS_SCRUB_ATTR_REPAIR_H__
 #define __XFS_SCRUB_ATTR_REPAIR_H__
 
+struct xrep_tempexch;
+
+int xrep_xattr_swap(struct xfs_scrub *sc, struct xrep_tempexch *tx);
 int xrep_xattr_reset_fork(struct xfs_scrub *sc);
+int xrep_xattr_reset_tempfile_fork(struct xfs_scrub *sc);
 
 #endif /* __XFS_SCRUB_ATTR_REPAIR_H__ */

fs/xfs/scrub/findparent.c

@@ -24,6 +24,7 @@
 #include "xfs_trans_space.h"
 #include "xfs_health.h"
 #include "xfs_exchmaps.h"
+#include "xfs_parent.h"
 #include "scrub/xfs_scrub.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
@@ -33,6 +34,7 @@
 #include "scrub/findparent.h"
 #include "scrub/readdir.h"
 #include "scrub/tempfile.h"
+#include "scrub/listxattr.h"
 
 /*
  * Finding the Parent of a Directory

fs/xfs/scrub/trace.h

@@ -2539,6 +2539,8 @@ DEFINE_EVENT(xrep_xattr_salvage_class, name, \
 	TP_ARGS(ip, flags, name, namelen, valuelen))
 DEFINE_XREP_XATTR_SALVAGE_EVENT(xrep_xattr_salvage_rec);
 DEFINE_XREP_XATTR_SALVAGE_EVENT(xrep_xattr_insert_rec);
+DEFINE_XREP_XATTR_SALVAGE_EVENT(xrep_parent_stash_xattr);
+DEFINE_XREP_XATTR_SALVAGE_EVENT(xrep_parent_insert_xattr);
 
 DECLARE_EVENT_CLASS(xrep_pptr_salvage_class,
 	TP_PROTO(struct xfs_inode *ip, unsigned int flags, const void *name,