xfs_scrub: improve reporting of file data media errors

When we report media errors, we should tell the administrator the file
offset and length of the bad region, not just the offset of the entire
file extent record that overlaps a bad region.

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

diff --git a/libfrog/bitmap.c b/libfrog/bitmap.c
index a75d085a9f194aefc2aa209b66f85963a4ed21f7..6a88ef48c4bbdb988eae5487bcf970efffe8b141 100644 (file)
--- a/libfrog/bitmap.c
+++ b/libfrog/bitmap.c
@@ -339,6 +339,43 @@ bitmap_iterate(
 }
 #endif
 
+/* Iterate the set regions of part of this bitmap. */
+int
+bitmap_iterate_range(
+       struct bitmap           *bmap,
+       uint64_t                start,
+       uint64_t                length,
+       int                     (*fn)(uint64_t, uint64_t, void *),
+       void                    *arg)
+{
+       struct avl64node        *firstn;
+       struct avl64node        *lastn;
+       struct avl64node        *pos;
+       struct avl64node        *n;
+       struct avl64node        *l;
+       struct bitmap_node      *ext;
+       int                     ret = 0;
+
+       pthread_mutex_lock(&bmap->bt_lock);
+
+       avl64_findranges(bmap->bt_tree, start, start + length, &firstn,
+                       &lastn);
+
+       if (firstn == NULL && lastn == NULL)
+               goto out;
+
+       avl_for_each_range_safe(pos, n, l, firstn, lastn) {
+               ext = container_of(pos, struct bitmap_node, btn_node);
+               ret = fn(ext->btn_start, ext->btn_length, arg);
+               if (ret)
+                       break;
+       }
+
+out:
+       pthread_mutex_unlock(&bmap->bt_lock);
+       return ret;
+}
+
 /* Do any bitmap extents overlap the given one?  (locked) */
 static bool
 __bitmap_test(

diff --git a/libfrog/bitmap.h b/libfrog/bitmap.h
index 759386a8f4f3609f45c003d4e2172ded70250ed9..043b77eece65b3ffdf64ff0ccee883ca482afce5 100644 (file)
--- a/libfrog/bitmap.h
+++ b/libfrog/bitmap.h
@@ -16,6 +16,8 @@ void bitmap_free(struct bitmap **bmap);
 int bitmap_set(struct bitmap *bmap, uint64_t start, uint64_t length);
 int bitmap_iterate(struct bitmap *bmap, int (*fn)(uint64_t, uint64_t, void *),
                void *arg);
+int bitmap_iterate_range(struct bitmap *bmap, uint64_t start, uint64_t length,
+               int (*fn)(uint64_t, uint64_t, void *), void *arg);
 bool bitmap_test(struct bitmap *bmap, uint64_t start,
                uint64_t len);
 bool bitmap_empty(struct bitmap *bmap);

diff --git a/scrub/phase6.c b/scrub/phase6.c
index f2a78a60978b0ac7a3db0c577ddd3b5930242c2e..5aeef1cb26b9a839c77625f8b2efe604ba6a1764 100644 (file)
--- a/scrub/phase6.c
+++ b/scrub/phase6.c
@@ -111,6 +111,41 @@ xfs_decode_special_owner(
 
 /* Routines to translate bad physical extents into file paths and offsets. */
 
+struct badfile_report {
+       struct scrub_ctx        *ctx;
+       const char              *descr;
+       struct xfs_bmap         *bmap;
+};
+
+/* Report on bad extents found during a media scan. */
+static int
+report_badfile(
+       uint64_t                start,
+       uint64_t                length,
+       void                    *arg)
+{
+       struct badfile_report   *br = arg;
+       unsigned long long      bad_offset;
+       unsigned long long      bad_length;
+
+       /* Clamp the bad region to the file mapping. */
+       if (start < br->bmap->bm_physical) {
+               length -= br->bmap->bm_physical - start;
+               start = br->bmap->bm_physical;
+       }
+       length = min(length, br->bmap->bm_length);
+
+       /* Figure out how far into the bmap is the bad mapping and report it. */
+       bad_offset = start - br->bmap->bm_physical;
+       bad_length = min(start + length,
+                        br->bmap->bm_physical + br->bmap->bm_length) - start;
+
+       str_error(br->ctx, br->descr,
+_("media error at data offset %llu length %llu."),
+                       br->bmap->bm_offset + bad_offset, bad_length);
+       return 0;
+}
+
 /* Report if this extent overlaps a bad region. */
 static bool
 report_data_loss(
@@ -122,8 +157,14 @@ report_data_loss(
        struct xfs_bmap                 *bmap,
        void                            *arg)
 {
+       struct badfile_report           br = {
+               .ctx                    = ctx,
+               .descr                  = descr,
+               .bmap                   = bmap,
+       };
        struct media_verify_state       *vs = arg;
        struct bitmap                   *bmp;
+       int                             ret;
 
        /* Only report errors for real extents. */
        if (bmap->bm_flags & (BMV_OF_PREALLOC | BMV_OF_DELALLOC))
@@ -134,11 +175,12 @@ report_data_loss(
        else
                bmp = vs->d_bad;
 
-       if (!bitmap_test(bmp, bmap->bm_physical, bmap->bm_length))
-               return true;
-
-       str_error(ctx, descr,
-_("offset %llu failed read verification."), bmap->bm_offset);
+       ret = bitmap_iterate_range(bmp, bmap->bm_physical, bmap->bm_length,
+                       report_badfile, &br);
+       if (ret) {
+               str_liberror(ctx, ret, descr);
+               return false;
+       }
        return true;
 }