On Tue, Feb 28, 2017 at 10:46:35AM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> If the reverse-mapping btree isn't available, fall back to the
> free space btrees to provide partial reverse mapping information.
> The online scrub tool can make use of even partial information to
> speed up the data block scan.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/xfs/xfs_fsmap.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 78 insertions(+), 3 deletions(-)
>
>
> diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
> index 2d0fa2a..56bbd24 100644
> --- a/fs/xfs/xfs_fsmap.c
> +++ b/fs/xfs/xfs_fsmap.c
> @@ -40,6 +40,7 @@
> #include "xfs_fsmap.h"
> #include "xfs_refcount.h"
> #include "xfs_refcount_btree.h"
> +#include "xfs_alloc_btree.h"
>
> /* Convert an xfs_fsmap to an fsmap. */
> void
> @@ -158,6 +159,9 @@ xfs_fsmap_owner_from_rmap(
> case XFS_RMAP_OWN_COW:
> dest->fmr_owner = XFS_FMR_OWN_COW;
> break;
> + case XFS_RMAP_OWN_NULL: /* "free" */
> + dest->fmr_owner = XFS_FMR_OWN_FREE;
> + break;
> default:
> return -EFSCORRUPTED;
> }
> @@ -411,6 +415,31 @@ xfs_getfsmap_rtdev_helper(
> return xfs_getfsmap_helper(cur->bc_tp, info, rec, rec_daddr);
> }
>
> +/* Transform a bnobt irec into a fsmap */
> +STATIC int
> +xfs_getfsmap_datadev_bnobt_helper(
> + struct xfs_btree_cur *cur,
> + struct xfs_alloc_rec_incore *rec,
> + void *priv)
> +{
> + struct xfs_mount *mp = cur->bc_mp;
> + struct xfs_getfsmap_info *info = priv;
> + struct xfs_rmap_irec irec;
> + xfs_fsblock_t fsb;
> + xfs_daddr_t rec_daddr;
> +
> + fsb = XFS_AGB_TO_FSB(mp, cur->bc_private.a.agno, rec->ar_startblock);
> + rec_daddr = XFS_FSB_TO_DADDR(mp, fsb);
> +
XFS_AGB_TO_DADDR()?
> + irec.rm_startblock = rec->ar_startblock;
> + irec.rm_blockcount = rec->ar_blockcount;
> + irec.rm_owner = XFS_RMAP_OWN_NULL; /* "free" */
> + irec.rm_offset = 0;
> + irec.rm_flags = 0;
> +
> + return xfs_getfsmap_helper(cur->bc_tp, info, &irec, rec_daddr);
> +}
> +
> /* Set rmap flags based on the getfsmap flags */
> static void
> xfs_getfsmap_set_irec_flags(
> @@ -633,6 +662,51 @@ xfs_getfsmap_datadev_rmapbt(
> xfs_getfsmap_datadev_rmapbt_end, NULL);
> }
>
> +/* Report any gap at the end of bnobt records. */
> +STATIC int
> +xfs_getfsmap_datadev_bnobt_end(
> + struct xfs_btree_cur *cur,
> + struct xfs_getfsmap_info *info,
> + void *priv)
> +{
> + struct xfs_alloc_rec_incore *key = priv;
> +
> + return xfs_getfsmap_datadev_bnobt_helper(cur, key + 1, info);
Nit: please use key[1] (or maybe call it keys to be clear) here and
below rather than pointer arithmetic.
Looks good aside from those couple nits and modulo the separate
_query()/_end() callbacks thing.
Brian
> +}
> +
> +/* Actually query the bno btree. */
> +STATIC int
> +xfs_getfsmap_datadev_bnobt_query(
> + struct xfs_trans *tp,
> + struct xfs_getfsmap_info *info,
> + struct xfs_btree_cur **curpp,
> + void *priv)
> +{
> + struct xfs_alloc_rec_incore *key = priv;
> +
> + *curpp = xfs_allocbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
> + info->agno, XFS_BTNUM_BNO);
> + key->ar_startblock = info->low.rm_startblock;
> + (key + 1)->ar_startblock = info->high.rm_startblock;
> + return xfs_alloc_query_range(*curpp, key, key + 1,
> + xfs_getfsmap_datadev_bnobt_helper, info);
> +}
> +
> +/* Execute a getfsmap query against the regular data device's bnobt. */
> +STATIC int
> +xfs_getfsmap_datadev_bnobt(
> + struct xfs_trans *tp,
> + struct xfs_fsmap *keys,
> + struct xfs_getfsmap_info *info)
> +{
> + struct xfs_alloc_rec_incore akeys[2];
> +
> + info->missing_owner = XFS_FMR_OWN_UNKNOWN;
> + return __xfs_getfsmap_datadev(tp, keys, info,
> + xfs_getfsmap_datadev_bnobt_query,
> + xfs_getfsmap_datadev_bnobt_end, &akeys[0]);
> +}
> +
> /* Do we recognize the device? */
> STATIC bool
> xfs_getfsmap_is_valid_device(
> @@ -714,8 +788,6 @@ xfs_getfsmap(
> int i;
> int error = 0;
>
> - if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
> - return -EOPNOTSUPP;
> if (head->fmh_iflags & ~FMH_IF_VALID)
> return -EINVAL;
> if (!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[0]) ||
> @@ -727,7 +799,10 @@ xfs_getfsmap(
> /* Set up our device handlers. */
> memset(handlers, 0, sizeof(handlers));
> handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev);
> - handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
> + if (xfs_sb_version_hasrmapbt(&mp->m_sb))
> + handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
> + else
> + handlers[0].fn = xfs_getfsmap_datadev_bnobt;
> if (mp->m_logdev_targp != mp->m_ddev_targp) {
> handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev);
> handlers[1].fn = xfs_getfsmap_logdev;
>
> --
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