xfs: replay unlocked parent pointer updates that accrue during xattr repair

There are a few places where the extended attribute repair code drops
the ILOCK to apply stashed xattrs to the temporary file.  Although
setxattr and removexattr are still locked out because we retain our hold
on the IOLOCK, this doesn't prevent renames from updating parent
pointers, because the VFS doesn't take i_rwsem on children that are
being moved.

Therefore, set up a dirent hook to capture parent pointer updates for
this file, and replay(?) the updates.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/scrub/trace.h

@@ -2602,6 +2602,43 @@ DEFINE_EVENT(xrep_xattr_class, name, \
 	TP_ARGS(ip, arg_ip))
 DEFINE_XREP_XATTR_EVENT(xrep_xattr_rebuild_tree);
 DEFINE_XREP_XATTR_EVENT(xrep_xattr_reset_fork);
+DEFINE_XREP_XATTR_EVENT(xrep_xattr_full_reset);
+
+DECLARE_EVENT_CLASS(xrep_xattr_pptr_scan_class,
+	TP_PROTO(struct xfs_inode *ip, const struct xfs_inode *dp,
+		 const struct xfs_name *name),
+	TP_ARGS(ip, dp, name),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(xfs_ino_t, parent_ino)
+		__field(unsigned int, parent_gen)
+		__field(unsigned int, namelen)
+		__dynamic_array(char, name, name->len)
+	),
+	TP_fast_assign(
+		__entry->dev = ip->i_mount->m_super->s_dev;
+		__entry->ino = ip->i_ino;
+		__entry->parent_ino = dp->i_ino;
+		__entry->parent_gen = VFS_IC(dp)->i_generation;
+		__entry->namelen = name->len;
+		memcpy(__get_str(name), name->name, name->len);
+	),
+	TP_printk("dev %d:%d ino 0x%llx parent_ino 0x%llx parent_gen 0x%x name '%.*s'",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->parent_ino,
+		  __entry->parent_gen,
+		  __entry->namelen,
+		  __get_str(name))
+)
+#define DEFINE_XREP_XATTR_PPTR_SCAN_EVENT(name) \
+DEFINE_EVENT(xrep_xattr_pptr_scan_class, name, \
+	TP_PROTO(struct xfs_inode *ip, const struct xfs_inode *dp, \
+		 const struct xfs_name *name), \
+	TP_ARGS(ip, dp, name))
+DEFINE_XREP_XATTR_PPTR_SCAN_EVENT(xrep_xattr_stash_parentadd);
+DEFINE_XREP_XATTR_PPTR_SCAN_EVENT(xrep_xattr_stash_parentremove);
 
 TRACE_EVENT(xrep_dir_recover_dirblock,
 	TP_PROTO(struct xfs_inode *dp, xfs_dablk_t dabno, uint32_t magic,
@@ -2748,6 +2785,42 @@ DEFINE_XREP_PARENT_SALVAGE_EVENT(xrep_dir_salvaged_parent);
 DEFINE_XREP_PARENT_SALVAGE_EVENT(xrep_findparent_dirent);
 DEFINE_XREP_PARENT_SALVAGE_EVENT(xrep_findparent_from_dcache);
 
+DECLARE_EVENT_CLASS(xrep_pptr_class,
+	TP_PROTO(struct xfs_inode *ip, const struct xfs_name *name,
+		 const struct xfs_parent_rec *pptr),
+	TP_ARGS(ip, name, pptr),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(xfs_ino_t, parent_ino)
+		__field(unsigned int, parent_gen)
+		__field(unsigned int, namelen)
+		__dynamic_array(char, name, name->len)
+	),
+	TP_fast_assign(
+		__entry->dev = ip->i_mount->m_super->s_dev;
+		__entry->ino = ip->i_ino;
+		__entry->parent_ino = be64_to_cpu(pptr->p_ino);
+		__entry->parent_gen = be32_to_cpu(pptr->p_gen);
+		__entry->namelen = name->len;
+		memcpy(__get_str(name), name->name, name->len);
+	),
+	TP_printk("dev %d:%d ino 0x%llx parent_ino 0x%llx parent_gen 0x%x name '%.*s'",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->parent_ino,
+		  __entry->parent_gen,
+		  __entry->namelen,
+		  __get_str(name))
+)
+#define DEFINE_XREP_PPTR_EVENT(name) \
+DEFINE_EVENT(xrep_pptr_class, name, \
+	TP_PROTO(struct xfs_inode *ip, const struct xfs_name *name, \
+		 const struct xfs_parent_rec *pptr), \
+	TP_ARGS(ip, name, pptr))
+DEFINE_XREP_PPTR_EVENT(xrep_xattr_replay_parentadd);
+DEFINE_XREP_PPTR_EVENT(xrep_xattr_replay_parentremove);
+
 TRACE_EVENT(xrep_nlinks_set_record,
 	TP_PROTO(struct xfs_mount *mp, xfs_ino_t ino,
 		 const struct xchk_nlink *obs),