On Tue, May 23, 2023 at 02:30:38PM +0530, Chandan Babu R wrote:
> This commit adds functionality to dump metadata from an XFS filesystem in
> newly introduced v2 format.
>
> Signed-off-by: Chandan Babu R <chandan.babu@xxxxxxxxxx>
> ---
> db/metadump.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 70 insertions(+), 3 deletions(-)
>
> diff --git a/db/metadump.c b/db/metadump.c
> index 9d7ad76ae..627436e68 100644
> --- a/db/metadump.c
> +++ b/db/metadump.c
> @@ -3037,6 +3037,69 @@ static struct metadump_ops metadump1_ops = {
> .release_metadump = release_metadump_v1,
> };
>
> +static int
> +init_metadump_v2(void)
> +{
> + struct xfs_metadump_header xmh = {0};
> + uint32_t compat_flags = 0;
> +
> + xmh.xmh_magic = cpu_to_be32(XFS_MD_MAGIC_V2);
> + xmh.xmh_version = 2;
> +
> + if (metadump.obfuscate)
> + compat_flags |= XFS_MD2_INCOMPAT_OBFUSCATED;
> + if (!metadump.zero_stale_data)
> + compat_flags |= XFS_MD2_INCOMPAT_FULLBLOCKS;
> + if (metadump.dirty_log)
> + compat_flags |= XFS_MD2_INCOMPAT_DIRTYLOG;
> +
> + xmh.xmh_compat_flags = cpu_to_be32(compat_flags);
> +
> + if (fwrite(&xmh, sizeof(xmh), 1, metadump.outf) != 1) {
> + print_warning("error writing to target file");
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +static int
> +write_metadump_v2(
> + enum typnm type,
> + char *data,
> + int64_t off,
> + int len)
> +{
> + struct xfs_meta_extent xme;
> + uint64_t addr;
> +
> + addr = off;
> + if (type == TYP_ELOG)
> + addr |= XME_ADDR_LOG_DEVICE;
> + else
> + addr |= XME_ADDR_DATA_DEVICE;
> +
> + xme.xme_addr = cpu_to_be64(addr);
> + xme.xme_len = cpu_to_be32(len);
> +
> + if (fwrite(&xme, sizeof(xme), 1, metadump.outf) != 1) {
> + print_warning("error writing to target file");
> + return -EIO;
> + }
> +
> + if (fwrite(data, len << BBSHIFT, 1, metadump.outf) != 1) {
> + print_warning("error writing to target file");
> + return -EIO;
> + }
Oh, I see, the v2 format is a straight stream -- first the v2 header,
then a xfs_meta_extent, then the buffer; and repeat #2 and #3 until
finished. That ought to be documented in the previous patch.
--D
> +
> + return 0;
> +}
> +
> +static struct metadump_ops metadump2_ops = {
> + .init_metadump = init_metadump_v2,
> + .write_metadump = write_metadump_v2,
> +};
> +
> static int
> metadump_f(
> int argc,
> @@ -3178,7 +3241,10 @@ metadump_f(
> }
> }
>
> - metadump.mdops = &metadump1_ops;
> + if (metadump.version == 1)
> + metadump.mdops = &metadump1_ops;
> + else
> + metadump.mdops = &metadump2_ops;
>
> ret = metadump.mdops->init_metadump();
> if (ret)
> @@ -3203,7 +3269,7 @@ metadump_f(
> exitcode = !copy_log(log_type);
>
> /* write the remaining index */
> - if (!exitcode)
> + if (!exitcode && metadump.mdops->end_write_metadump)
> exitcode = metadump.mdops->end_write_metadump() < 0;
>
> if (metadump.progress_since_warning)
> @@ -3223,7 +3289,8 @@ metadump_f(
> while (iocur_sp > start_iocur_sp)
> pop_cur();
>
> - metadump.mdops->release_metadump();
> + if (metadump.mdops->release_metadump)
> + metadump.mdops->release_metadump();
>
> out:
> return 0;
> --
> 2.39.1
>
