[PATCH] xfs_db: allow write -d to inodes

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

Add a helper function to xfs_db so that we can recalculate the CRC of an
inode whose field we just wrote.  This enables us to write arbitrary
values with a good CRC for the purpose of checking the read verifiers on
a v5 filesystem.  Mention this newfound ability in the manpage.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 db/io.c           |   11 +++++++++++
 db/io.h           |    1 +
 db/write.c        |    7 ++++++-
 man/man8/xfs_db.8 |    7 ++++++-
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/db/io.c b/db/io.c
index f398195..67ed5f9 100644
--- a/db/io.c
+++ b/db/io.c
@@ -465,6 +465,17 @@ xfs_dummy_verify(
 }
 
 void
+xfs_verify_recalc_inode_crc(
+	struct xfs_buf *bp)
+{
+	ASSERT(iocur_top->ino_buf);
+	ASSERT(iocur_top->bp == bp);
+
+	libxfs_dinode_calc_crc(mp, iocur_top->data);
+	iocur_top->ino_crc_ok = 1;
+}
+
+void
 xfs_verify_recalc_crc(
 	struct xfs_buf *bp)
 {
diff --git a/db/io.h b/db/io.h
index c69e9ce..12d96c2 100644
--- a/db/io.h
+++ b/db/io.h
@@ -64,6 +64,7 @@ extern void	set_cur(const struct typ *t, __int64_t d, int c, int ring_add,
 extern void     ring_add(void);
 extern void	set_iocur_type(const struct typ *t);
 extern void	xfs_dummy_verify(struct xfs_buf *bp);
+extern void	xfs_verify_recalc_inode_crc(struct xfs_buf *bp);
 extern void	xfs_verify_recalc_crc(struct xfs_buf *bp);
 
 /*
diff --git a/db/write.c b/db/write.c
index 5c83874..70c9865 100644
--- a/db/write.c
+++ b/db/write.c
@@ -137,7 +137,9 @@ write_f(
 		return 0;
 	}
 
-	if (invalid_data && iocur_top->typ->crc_off == TYP_F_NO_CRC_OFF) {
+	if (invalid_data &&
+	    iocur_top->typ->crc_off == TYP_F_NO_CRC_OFF &&
+	    !iocur_top->ino_buf) {
 		dbprintf(_("Cannot recalculate CRCs on this type of object\n"));
 		return 0;
 	}
@@ -164,6 +166,9 @@ write_f(
 	if (corrupt) {
 		local_ops.verify_write = xfs_dummy_verify;
 		dbprintf(_("Allowing write of corrupted data and bad CRC\n"));
+	} else if (iocur_top->ino_buf) {
+		local_ops.verify_write = xfs_verify_recalc_inode_crc;
+		dbprintf(_("Allowing write of corrupted inode with good CRC\n"));
 	} else { /* invalid data */
 		local_ops.verify_write = xfs_verify_recalc_crc;
 		dbprintf(_("Allowing write of corrupted data with good CRC\n"));
diff --git a/man/man8/xfs_db.8 b/man/man8/xfs_db.8
index 460d89d..b1c341d 100644
--- a/man/man8/xfs_db.8
+++ b/man/man8/xfs_db.8
@@ -755,7 +755,7 @@ and
 bits respectively, and their string equivalent reported
 (but no modifications are made).
 .TP
-.BI "write [\-c] [" "field value" "] ..."
+.BI "write [\-c] [\-d] [" "field value" "] ..."
 Write a value to disk.
 Specific fields can be set in structures (struct mode),
 or a block can be set to data values (data mode),
@@ -778,6 +778,11 @@ with no arguments gives more information on the allowed commands.
 .B \-c
 Skip write verifiers and CRC recalculation; allows invalid data to be written
 to disk.
+.TP 0.4i
+.B \-d
+Skip write verifiers but perform CRC recalculation.
+This allows invalid data, including inodes, to be written to disk to
+test detection of invalid data.
 .RE
 .SH TYPES
 This section gives the fields in each structure type and their meanings.