From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: sandeen@sandeen.net, darrick.wong@oracle.com
Cc: linux-xfs@vger.kernel.org, alex@zadara.com
Subject: [PATCH 7/7] xfs_repair: try to correct sb_unit value from secondaries
Date: Tue, 04 Feb 2020 16:47:21 -0800 [thread overview]
Message-ID: <158086364145.2079685.5986767044268901944.stgit@magnolia> (raw)
In-Reply-To: <158086359783.2079685.9581209719946834913.stgit@magnolia>
From: Darrick J. Wong <darrick.wong@oracle.com>
If the primary superblock's sb_unit leads to a rootino calculation that
doesn't match sb_rootino /but/ we can find a secondary superblock whose
sb_unit does match, fix the primary.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
libxfs/libxfs_api_defs.h | 1 +
repair/xfs_repair.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 80 insertions(+)
diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
index 7c629c62..1a438e58 100644
--- a/libxfs/libxfs_api_defs.h
+++ b/libxfs/libxfs_api_defs.h
@@ -143,6 +143,7 @@
#define xfs_rtfree_extent libxfs_rtfree_extent
#define xfs_sb_from_disk libxfs_sb_from_disk
#define xfs_sb_quota_from_disk libxfs_sb_quota_from_disk
+#define xfs_sb_read_secondary libxfs_sb_read_secondary
#define xfs_sb_to_disk libxfs_sb_to_disk
#define xfs_symlink_blocks libxfs_symlink_blocks
#define xfs_symlink_hdr_ok libxfs_symlink_hdr_ok
diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
index b34d41d4..eb1ce546 100644
--- a/repair/xfs_repair.c
+++ b/repair/xfs_repair.c
@@ -457,6 +457,84 @@ has_plausible_rootdir(
return ret;
}
+/*
+ * If any of the secondary SBs contain a *correct* value for sunit, write that
+ * back to the primary superblock.
+ */
+static void
+guess_correct_sunit(
+ struct xfs_mount *mp)
+{
+ struct xfs_sb sb;
+ struct xfs_buf *bp;
+ xfs_ino_t calc_rootino = NULLFSINO;
+ xfs_agnumber_t agno;
+ unsigned int new_sunit;
+ unsigned int sunit_guess;
+ int error;
+
+ /* Try reading secondary supers to see if we find a good sb_unit. */
+ for (agno = 1; agno < mp->m_sb.sb_agcount; agno++) {
+ error = -libxfs_sb_read_secondary(mp, NULL, agno, &bp);
+ if (error)
+ continue;
+ libxfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp));
+ libxfs_putbuf(bp);
+
+ calc_rootino = libxfs_ialloc_calc_rootino(mp, sb.sb_unit);
+ if (calc_rootino == mp->m_sb.sb_rootino)
+ break;
+ }
+
+ /* If we found a reasonable value, log where we found it. */
+ if (calc_rootino == mp->m_sb.sb_rootino) {
+ do_warn(_("AG %u superblock contains plausible sb_unit value\n"),
+ agno);
+ new_sunit = sb.sb_unit;
+ goto fix;
+ }
+
+ /* Try successive powers of two. */
+ for (sunit_guess = 1;
+ sunit_guess <= XFS_AG_MAX_BLOCKS(mp->m_sb.sb_blocklog);
+ sunit_guess *= 2) {
+ calc_rootino = libxfs_ialloc_calc_rootino(mp, sunit_guess);
+ if (calc_rootino == mp->m_sb.sb_rootino)
+ break;
+ }
+
+ /* If we found a reasonable value, log where we found it. */
+ if (calc_rootino == mp->m_sb.sb_rootino) {
+ do_warn(_("Found an sb_unit value that looks plausible\n"));
+ new_sunit = sunit_guess;
+ goto fix;
+ }
+
+ do_warn(_("Could not estimate a plausible sb_unit value\n"));
+ return;
+
+fix:
+ if (!no_modify)
+ do_warn(_("Resetting sb_unit to %u\n"), new_sunit);
+ else
+ do_warn(_("Would reset sb_unit to %u\n"), new_sunit);
+
+ /*
+ * Just set the value -- safe since the superblock doesn't get flushed
+ * out if no_modify is set.
+ */
+ mp->m_sb.sb_unit = new_sunit;
+
+ /* Make sure that swidth is still a multiple of sunit. */
+ if (mp->m_sb.sb_width % mp->m_sb.sb_unit == 0)
+ return;
+
+ if (!no_modify)
+ do_warn(_("Resetting sb_width to %u\n"), new_sunit);
+ else
+ do_warn(_("Would reset sb_width to %u\n"), new_sunit);
+}
+
/*
* Make sure that the first 3 inodes in the filesystem are the root directory,
* the realtime bitmap, and the realtime summary, in that order.
@@ -480,6 +558,7 @@ calc_mkfs(
do_warn(
_("sb root inode value %" PRIu64 " valid but in unaligned location (expected %"PRIu64") possibly due to sunit change\n"),
mp->m_sb.sb_rootino, rootino);
+ guess_correct_sunit(mp);
rootino = mp->m_sb.sb_rootino;
}
next prev parent reply other threads:[~2020-02-05 0:47 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-05 0:46 [PATCH v4 0/7] xfs_repair: do not trash valid root dirs Darrick J. Wong
2020-02-05 0:46 ` [PATCH 1/7] xfs_repair: replace verify_inum with libxfs inode validators Darrick J. Wong
2020-02-05 0:50 ` Darrick J. Wong
2020-02-17 13:50 ` Christoph Hellwig
2020-02-19 4:32 ` Darrick J. Wong
2020-02-26 16:55 ` Eric Sandeen
2020-02-05 0:46 ` [PATCH 2/7] mkfs: check root inode location Darrick J. Wong
2020-02-17 13:50 ` Christoph Hellwig
2020-02-05 0:46 ` [PATCH 3/7] xfs_repair: enforce that inode btree chunks can't point to AG headers Darrick J. Wong
2020-02-17 13:51 ` Christoph Hellwig
2020-02-26 17:09 ` Eric Sandeen
2020-02-26 17:24 ` Darrick J. Wong
2020-02-26 17:34 ` Eric Sandeen
2020-02-26 17:19 ` Eric Sandeen
2020-02-26 17:32 ` Darrick J. Wong
2020-02-26 17:40 ` Eric Sandeen
2020-02-05 0:47 ` [PATCH 4/7] xfs_repair: refactor fixed inode location checks Darrick J. Wong
2020-02-17 13:51 ` Christoph Hellwig
2020-02-05 0:47 ` [PATCH 5/7] xfs_repair: use libxfs function to calculate root inode location Darrick J. Wong
2020-02-17 13:53 ` Christoph Hellwig
2020-02-05 0:47 ` [PATCH 6/7] xfs_repair: check plausibility of root dir pointer before trashing it Darrick J. Wong
2020-02-17 13:53 ` Christoph Hellwig
2020-02-05 0:47 ` Darrick J. Wong [this message]
2020-02-17 13:55 ` [PATCH 7/7] xfs_repair: try to correct sb_unit value from secondaries Christoph Hellwig
2020-02-26 17:42 ` Eric Sandeen
2020-02-26 17:55 ` Darrick J. Wong
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