The prior effort to identify the actual root inode in a filesystem
failed in the (rare) case where inodes were allocated with a lower
number than the root. As a result, the wrong root inode number
went into the dump, and restore would fail with:
xfsrestore: tree.c:757: tree_begindir: Assertion `ino != persp->p_rootino || hardh == persp->p_rooth' failed.
Fix this by iterating over a chunk's worth of inodes until we find
a directory inode with generation 0, which should only be true
for the real root inode.
Fixes: 25195ebf107 ("xfsdump: handle bind mount targets")
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---
diff --git a/dump/content.c b/dump/content.c
index 30232d4..9f9c03b 100644
--- a/dump/content.c
+++ b/dump/content.c
@@ -1384,7 +1384,7 @@ baseuuidbypass:
/* figure out the ino for the root directory of the fs
* and get its struct xfs_bstat for inomap_build(). This could
* be a bind mount; don't ask for the mount point inode,
- * find the actual lowest inode number in the filesystem.
+ * actually find the root inode number in the filesystem.
*/
{
stat64_t rootstat;
@@ -1404,20 +1404,36 @@ baseuuidbypass:
(struct xfs_bstat *)calloc(1, sizeof(struct xfs_bstat));
assert(sc_rootxfsstatp);
- /* Get the first valid (i.e. root) inode in this fs */
- bulkreq.lastip = (__u64 *)&lastino;
- bulkreq.icount = 1;
- bulkreq.ubuffer = sc_rootxfsstatp;
- bulkreq.ocount = &ocount;
- if (ioctl(sc_fsfd, XFS_IOC_FSBULKSTAT, &bulkreq) < 0) {
- mlog(MLOG_ERROR,
- _("failed to get bulkstat information for root inode\n"));
+ /*
+ * Find the root inode in this fs. It is (rarely) possible to
+ * have a non-root inode come before the root inode, so iterate
+ * over a chunk's worth looking for the first dir inode with
+ * bs_gen == 0, which should only be true for the root inode.
+ */
+ for (i = 0; i < 64; i++) {
+ bulkreq.lastip = (__u64 *)&lastino;
+ bulkreq.icount = 1;
+ bulkreq.ubuffer = sc_rootxfsstatp;
+ bulkreq.ocount = &ocount;
+ if (ioctl(sc_fsfd, XFS_IOC_FSBULKSTAT, &bulkreq) < 0) {
+ mlog(MLOG_ERROR,
+_("failed to get bulkstat information for root inode\n"));
+ return BOOL_FALSE;
+ }
+ /* found it? */
+ if ((sc_rootxfsstatp->bs_mode & S_IFMT) == S_IFDIR &&
+ sc_rootxfsstatp->bs_gen == 0)
+ break;
+ }
+
+ if (i == 64) {
+ mlog(MLOG_ERROR, _("failed to find root inode\n"));
return BOOL_FALSE;
}
if (sc_rootxfsstatp->bs_ino != rootstat.st_ino)
mlog (MLOG_NORMAL | MLOG_NOTE,
- _("root ino %lld differs from mount dir ino %lld, bind mount?\n"),
+_("root ino %lld differs from mount dir ino %lld, bind mount?\n"),
sc_rootxfsstatp->bs_ino, rootstat.st_ino);
}
