xfs: have getfsmap fall back to the freesp btrees when rmap is not present

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@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong 2017-03-28 14:56:37 -07:00
parent e89c041338
commit a1cae7283d
1 changed files with 69 additions and 3 deletions

View File

@ -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;
}
@ -362,6 +366,30 @@ xfs_getfsmap_datadev_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_daddr_t rec_daddr;
rec_daddr = XFS_AGB_TO_DADDR(mp, cur->bc_private.a.agno,
rec->ar_startblock);
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(
@ -572,6 +600,43 @@ xfs_getfsmap_datadev_rmapbt(
xfs_getfsmap_datadev_rmapbt_query, NULL);
}
/* 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;
/* Report any gap at the end of the last AG. */
if (info->last)
return xfs_getfsmap_datadev_bnobt_helper(*curpp, &key[1], info);
/* Allocate cursor for this AG and query_range it. */
*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, &akeys[0]);
}
/* Do we recognize the device? */
STATIC bool
xfs_getfsmap_is_valid_device(
@ -652,8 +717,6 @@ 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]) ||
@ -665,7 +728,10 @@ 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;