xfs: explicitly initialize meta_scrub_ops array by type

An implicit mapping to type by order of initialization seems
error-prone, and doesn't lend itself to cscope-ing.

Also add sanity checks about size of array vs. max types,
and a defensive check that ->scrub exists before using it.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index ab3aef2..53cd9df 100644 (file)
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -167,104 +167,104 @@ xfs_scrub_teardown(
 /* Scrubbing dispatch. */
 
 static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
-       { /* ioctl presence test */
+       [XFS_SCRUB_TYPE_PROBE] = {      /* ioctl presence test */
                .setup  = xfs_scrub_setup_fs,
                .scrub  = xfs_scrub_probe,
        },
-       { /* superblock */
+       [XFS_SCRUB_TYPE_SB] = {         /* superblock */
                .setup  = xfs_scrub_setup_ag_header,
                .scrub  = xfs_scrub_superblock,
        },
-       { /* agf */
+       [XFS_SCRUB_TYPE_AGF] = {        /* agf */
                .setup  = xfs_scrub_setup_ag_header,
                .scrub  = xfs_scrub_agf,
        },
-       { /* agfl */
+       [XFS_SCRUB_TYPE_AGFL]= {        /* agfl */
                .setup  = xfs_scrub_setup_ag_header,
                .scrub  = xfs_scrub_agfl,
        },
-       { /* agi */
+       [XFS_SCRUB_TYPE_AGI] = {        /* agi */
                .setup  = xfs_scrub_setup_ag_header,
                .scrub  = xfs_scrub_agi,
        },
-       { /* bnobt */
+       [XFS_SCRUB_TYPE_BNOBT] = {      /* bnobt */
                .setup  = xfs_scrub_setup_ag_allocbt,
                .scrub  = xfs_scrub_bnobt,
        },
-       { /* cntbt */
+       [XFS_SCRUB_TYPE_CNTBT] = {      /* cntbt */
                .setup  = xfs_scrub_setup_ag_allocbt,
                .scrub  = xfs_scrub_cntbt,
        },
-       { /* inobt */
+       [XFS_SCRUB_TYPE_INOBT] = {      /* inobt */
                .setup  = xfs_scrub_setup_ag_iallocbt,
                .scrub  = xfs_scrub_inobt,
        },
-       { /* finobt */
+       [XFS_SCRUB_TYPE_FINOBT] = {     /* finobt */
                .setup  = xfs_scrub_setup_ag_iallocbt,
                .scrub  = xfs_scrub_finobt,
                .has    = xfs_sb_version_hasfinobt,
        },
-       { /* rmapbt */
+       [XFS_SCRUB_TYPE_RMAPBT] = {     /* rmapbt */
                .setup  = xfs_scrub_setup_ag_rmapbt,
                .scrub  = xfs_scrub_rmapbt,
                .has    = xfs_sb_version_hasrmapbt,
        },
-       { /* refcountbt */
+       [XFS_SCRUB_TYPE_REFCNTBT] = {   /* refcountbt */
                .setup  = xfs_scrub_setup_ag_refcountbt,
                .scrub  = xfs_scrub_refcountbt,
                .has    = xfs_sb_version_hasreflink,
        },
-       { /* inode record */
+       [XFS_SCRUB_TYPE_INODE] = {      /* inode record */
                .setup  = xfs_scrub_setup_inode,
                .scrub  = xfs_scrub_inode,
        },
-       { /* inode data fork */
+       [XFS_SCRUB_TYPE_BMBTD] = {      /* inode data fork */
                .setup  = xfs_scrub_setup_inode_bmap,
                .scrub  = xfs_scrub_bmap_data,
        },
-       { /* inode attr fork */
+       [XFS_SCRUB_TYPE_BMBTA] = {      /* inode attr fork */
                .setup  = xfs_scrub_setup_inode_bmap,
                .scrub  = xfs_scrub_bmap_attr,
        },
-       { /* inode CoW fork */
+       [XFS_SCRUB_TYPE_BMBTC] = {      /* inode CoW fork */
                .setup  = xfs_scrub_setup_inode_bmap,
                .scrub  = xfs_scrub_bmap_cow,
        },
-       { /* directory */
+       [XFS_SCRUB_TYPE_DIR] = {        /* directory */
                .setup  = xfs_scrub_setup_directory,
                .scrub  = xfs_scrub_directory,
        },
-       { /* extended attributes */
+       [XFS_SCRUB_TYPE_XATTR] = {      /* extended attributes */
                .setup  = xfs_scrub_setup_xattr,
                .scrub  = xfs_scrub_xattr,
        },
-       { /* symbolic link */
+       [XFS_SCRUB_TYPE_SYMLINK] = {    /* symbolic link */
                .setup  = xfs_scrub_setup_symlink,
                .scrub  = xfs_scrub_symlink,
        },
-       { /* parent pointers */
+       [XFS_SCRUB_TYPE_PARENT] = {     /* parent pointers */
                .setup  = xfs_scrub_setup_parent,
                .scrub  = xfs_scrub_parent,
        },
-       { /* realtime bitmap */
+       [XFS_SCRUB_TYPE_RTBITMAP] = {   /* realtime bitmap */
                .setup  = xfs_scrub_setup_rt,
                .scrub  = xfs_scrub_rtbitmap,
                .has    = xfs_sb_version_hasrealtime,
        },
-       { /* realtime summary */
+       [XFS_SCRUB_TYPE_RTSUM] = {      /* realtime summary */
                .setup  = xfs_scrub_setup_rt,
                .scrub  = xfs_scrub_rtsummary,
                .has    = xfs_sb_version_hasrealtime,
        },
-       { /* user quota */
+       [XFS_SCRUB_TYPE_UQUOTA] = {     /* user quota */
                .setup = xfs_scrub_setup_quota,
                .scrub = xfs_scrub_quota,
        },
-       { /* group quota */
+       [XFS_SCRUB_TYPE_GQUOTA] = {     /* group quota */
                .setup = xfs_scrub_setup_quota,
                .scrub = xfs_scrub_quota,
        },
-       { /* project quota */
+       [XFS_SCRUB_TYPE_PQUOTA] = {     /* project quota */
                .setup = xfs_scrub_setup_quota,
                .scrub = xfs_scrub_quota,
        },
@@ -296,6 +296,9 @@ xfs_scrub_metadata(
        bool                            try_harder = false;
        int                             error = 0;
 
+       BUILD_BUG_ON(sizeof(meta_scrub_ops) !=
+               (sizeof(struct xfs_scrub_meta_ops) * XFS_SCRUB_TYPE_NR));
+
        trace_xfs_scrub_start(ip, sm, error);
 
        /* Forbidden if we are shut down or mounted norecovery. */
@@ -319,7 +322,7 @@ xfs_scrub_metadata(
        if (sm->sm_type >= XFS_SCRUB_TYPE_NR)
                goto out;
        ops = &meta_scrub_ops[sm->sm_type];
-       if (ops->scrub == NULL)
+       if (ops->setup == NULL || ops->scrub == NULL)
                goto out;
 
        /*