xfs: allow userspace to rebuild metadata structures

Add a new (superuser-only) flag to the online metadata repair ioctl to
force it to rebuild structures, even if they're not broken.  We will use
this to move metadata structures out of the way during a free space
defragmentation operation.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index 2cbf9ea..6360073 100644 (file)
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -743,7 +743,11 @@ struct xfs_scrub_metadata {
  */
 #define XFS_SCRUB_OFLAG_NO_REPAIR_NEEDED (1u << 7)
 
-#define XFS_SCRUB_FLAGS_IN     (XFS_SCRUB_IFLAG_REPAIR)
+/* i: Rebuild the data structure. */
+#define XFS_SCRUB_IFLAG_FORCE_REBUILD  (1u << 8)
+
+#define XFS_SCRUB_FLAGS_IN     (XFS_SCRUB_IFLAG_REPAIR | \
+                                XFS_SCRUB_IFLAG_FORCE_REBUILD)
 #define XFS_SCRUB_FLAGS_OUT    (XFS_SCRUB_OFLAG_CORRUPT | \
                                 XFS_SCRUB_OFLAG_PREEN | \
                                 XFS_SCRUB_OFLAG_XFAIL | \

diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index aade9d3..e92129d 100644 (file)
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -409,6 +409,11 @@ xchk_validate_inputs(
                goto out;
        }
 
+       /* No rebuild without repair. */
+       if ((sm->sm_flags & XFS_SCRUB_IFLAG_FORCE_REBUILD) &&
+           !(sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
+               return -EINVAL;
+
        /*
         * We only want to repair read-write v5+ filesystems.  Defer the check
         * for ops->repair until after our scrub confirms that we need to
@@ -537,8 +542,12 @@ retry_op:
            !(sc->flags & XREP_ALREADY_FIXED)) {
                bool needs_fix = xchk_needs_repair(sc->sm);
 
+               /* Userspace asked us to rebuild the structure regardless. */
+               if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_FORCE_REBUILD)
+                       needs_fix = true;
+
                /* Let debug users force us into the repair routines. */
-               if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_FORCE_SCRUB_REPAIR))
+               if (XFS_TEST_ERROR(needs_fix, mp, XFS_ERRTAG_FORCE_SCRUB_REPAIR))
                        needs_fix = true;
 
                /*

diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index 98f6773..fca99e8 100644 (file)
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -98,7 +98,8 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS);
        { XFS_SCRUB_OFLAG_XCORRUPT,             "xcorrupt" }, \
        { XFS_SCRUB_OFLAG_INCOMPLETE,           "incomplete" }, \
        { XFS_SCRUB_OFLAG_WARNING,              "warning" }, \
-       { XFS_SCRUB_OFLAG_NO_REPAIR_NEEDED,     "norepair" }
+       { XFS_SCRUB_OFLAG_NO_REPAIR_NEEDED,     "norepair" }, \
+       { XFS_SCRUB_IFLAG_FORCE_REBUILD,        "rebuild" }
 
 #define XFS_SCRUB_STATE_STRINGS \
        { XCHK_TRY_HARDER,                      "try_harder" }, \