On 4/11/17 9:09 PM, Eric Sandeen wrote:
> On 4/11/17 5:53 PM, Darrick J. Wong wrote:
>> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>>
>> 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.
>
> -d isn't new, so I'd really rather have a patch to document the existing
> behavior, followed by a patch to extend it to inodes.
>
> There are actually several structures for which -d still won't work, so
> it would be good if that fact were documented - reading "including
> inodes" may leave some heads scratching.
>
> Let me ruminate on the inode crc writing, I have this nagging feeling
> that there's an easier generic way to handle these structures,
> ...but I'm probably wrong.
I don't know where I was going with that idea. :/
I can split this up into a manpage patch and an inode crc patch on
the way in if you'd like.
For the content as-is,
Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx>
-Eric
> Thanks,
> -Eric
>
>> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>> ---
>> 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.
>>
>
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