/*
* Verify that an AG inode number pointer neither points outside the AG
* nor points at static metadata.
*/
bool
xfs_verify_agino(
struct xfs_mount *mp,
xfs_agnumber_t agno,
xfs_agino_t agino)
{
xfs_agino_t first;
xfs_agino_t last;
xfs_agino_range(mp, agno, &first, &last);
return agino >= first && agino <= last;
}
/* Calculate the range of valid icount values. */
static void
xfs_icount_range(
struct xfs_mount *mp,
unsigned long long *min,
unsigned long long *max)
{
unsigned long long nr_inos = 0;
xfs_agnumber_t agno;
/* root, rtbitmap, rtsum all live in the first chunk */
*min = XFS_INODES_PER_CHUNK;
for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
xfs_agino_t first, last;
xfs_agino_range(mp, agno, &first, &last);
nr_inos += last - first + 1;
}
*max = nr_inos;
}
/*
* Figure out how many blocks to reserve for an AG repair. We calculate the
* worst case estimate for the number of blocks we'd need to rebuild one of
* any type of per-AG btree.
*/
xfs_extlen_t
xrep_calc_ag_resblks(
struct xfs_scrub *sc)
{
struct xfs_mount *mp = sc->mp;
struct xfs_scrub_metadata *sm = sc->sm;
struct xfs_perag *pag;
struct xfs_buf *bp;
xfs_agino_t icount = NULLAGINO;
xfs_extlen_t aglen = NULLAGBLOCK;
xfs_extlen_t usedlen;
xfs_extlen_t freelen;
xfs_extlen_t bnobt_sz;
xfs_extlen_t inobt_sz;
xfs_extlen_t rmapbt_sz;
xfs_extlen_t refcbt_sz;
int error;
if (!(sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
return 0;
pag = xfs_perag_get(mp, sm->sm_agno);
if (pag->pagi_init) {
/* Use in-core icount if possible. */
icount = pag->pagi_count;
} else {
/* Try to get the actual counters from disk. */
error = xfs_ialloc_read_agi(mp, NULL, sm->sm_agno, &bp);
if (!error) {
icount = pag->pagi_count;
xfs_buf_relse(bp);
}
}
/* Now grab the block counters from the AGF. */
error = xfs_alloc_read_agf(mp, NULL, sm->sm_agno, 0, &bp);
if (!error) {
aglen = be32_to_cpu(XFS_BUF_TO_AGF(bp)->agf_length);
freelen = be32_to_cpu(XFS_BUF_TO_AGF(bp)->agf_freeblks);
usedlen = aglen - freelen;
xfs_buf_relse(bp);
}
xfs_perag_put(pag);
/* If the icount is impossible, make some worst-case assumptions. */
if (icount == NULLAGINO ||
!xfs_verify_agino(mp, sm->sm_agno, icount)) {
xfs_agino_t first, last;
xfs_agino_range(mp, sm->sm_agno, &first, &last);
icount = last - first + 1;
}
/* If the block counts are impossible, make worst-case assumptions. */
if (aglen == NULLAGBLOCK ||
aglen != xfs_ag_block_count(mp, sm->sm_agno) ||
freelen >= aglen) {
aglen = xfs_ag_block_count(mp, sm->sm_agno);
freelen = aglen;
usedlen = aglen;
}
trace_xrep_calc_ag_resblks(mp, sm->sm_agno, icount, aglen,
freelen, usedlen);
/*
* Figure out how many blocks we'd need worst case to rebuild
* each type of btree. Note that we can only rebuild the
* bnobt/cntbt or inobt/finobt as pairs.
*/
bnobt_sz = 2 * xfs_allocbt_calc_size(mp, freelen);
if (xfs_sb_version_hassparseinodes(&mp->m_sb))
inobt_sz = xfs_iallocbt_calc_size(mp, icount /
XFS_INODES_PER_HOLEMASK_BIT);
else
inobt_sz = xfs_iallocbt_calc_size(mp, icount /
XFS_INODES_PER_CHUNK);
if (xfs_sb_version_hasfinobt(&mp->m_sb))
inobt_sz *= 2;
if (xfs_sb_version_hasreflink(&mp->m_sb))
refcbt_sz = xfs_refcountbt_calc_size(mp, usedlen);
else
refcbt_sz = 0;
if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
/*
* Guess how many blocks we need to rebuild the rmapbt.
* For non-reflink filesystems we can't have more records than
* used blocks. However, with reflink it's possible to have
* more than one rmap record per AG block. We don't know how
* many rmaps there could be in the AG, so we start off with
* what we hope is an generous over-estimation.
*/
if (xfs_sb_version_hasreflink(&mp->m_sb))
rmapbt_sz = xfs_rmapbt_calc_size(mp,
(unsigned long long)aglen * 2);
else
rmapbt_sz = xfs_rmapbt_calc_size(mp, usedlen);
} else {
rmapbt_sz = 0;
}
trace_xrep_calc_ag_resblks_btsize(mp, sm->sm_agno, bnobt_sz,
inobt_sz, rmapbt_sz, refcbt_sz);
return max(max(bnobt_sz, inobt_sz), max(rmapbt_sz, refcbt_sz));
}
