@@ -2760,6 +2760,16 @@ metadump_f(
return 0;
}
+ /*
+ * on load, we sanity-checked agcount and possibly set to 1
+ * if it was corrupted and large.
+ */
+ if (mp->m_sb.sb_agcount == 1 &&
+ XFS_MAX_DBLOCKS(&mp->m_sb) < mp->m_sb.sb_dblocks) {
+ print_warning("truncated agcount, giving up");
+ return 0;
+ }
+
while ((c = getopt(argc, argv, "aegm:ow")) != EOF) {
switch (c) {
case 'a':
@@ -817,6 +817,29 @@ libxfs_mount(
return NULL;
}
+ /*
+ * libxfs_initialize_perag will allocate a perag structure for each ag.
+ * If agcount is corrupted and insanely high, this will OOM the box.
+ * If the agount seems (arbitrarily) high, try to read what would be
+ * the last AG, and if that fails for a relatively high agcount, just
+ * read the first one and let the user know to check the geometry.
+ */
+ if (sbp->sb_agcount > 1000000) {
+ bp = libxfs_readbuf(mp->m_dev,
+ XFS_AG_DADDR(mp, sbp->sb_agcount - 1, 0), 1,
+ !(flags & LIBXFS_MOUNT_DEBUGGER), NULL);
+ if (bp->b_error) {
+ fprintf(stderr, _("%s: read of AG %u failed\n"),
+ progname, sbp->sb_agcount);
+ if (!(flags & LIBXFS_MOUNT_DEBUGGER))
+ return NULL;
+ fprintf(stderr, _("%s: limiting reads to AG 0\n"),
+ progname);
+ sbp->sb_agcount = 1;
+ }
+ libxfs_putbuf(bp);
+ }
+
error = libxfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
if (error) {
fprintf(stderr, _("%s: perag init failed\n"),
Before we get into libxfs_initialize_perag and try to blindly allocate a perag struct for every (possibly corrupted number of) AGs, see if we can read the last one. If not, assume it's corrupt, and load only the first AG. Do this only for an arbitrarily high-ish agcount, so that normal-ish geometry on a possibly truncated file or device will still do its best to make all readable AGs available. Teach metadump to detect this and exit appropriately if truncated. Signed-off-by: Eric Sandeen <sandeen@redhat.com> --- v1->v6: Tale of woe. v7: blow it all up v8: use bare libxfs_readbuf so verifiers don't matter, "ours goes to 1 million!" v9: Fix printf format, exit metadump with error if things look wonky. -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html