During FS shrinking, if an affected AG is not empty, we need to truncate it accordingly.
Signed-off-by: Jie Liu <jeff.liu@xxxxxxxxxx>
---
fs/xfs/xfs_fsops.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 94 insertions(+), 0 deletions(-)
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 24de23f..04a21d1 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -855,6 +855,100 @@ error0:
}
/*
+ * Truncate the given AG and update the metadatas accordingly.
+ */
+static int
+xfs_truncate_ag(
+ xfs_mount_t *mp,
+ xfs_agnumber_t agno,
+ xfs_rfsblock_t tsize,
+ xfs_extlen_t *nfree)
+{
+ xfs_agf_t *agf;
+ xfs_agi_t *agi;
+ xfs_buf_t *bp;
+ xfs_perag_t *pag;
+ xfs_alloc_rec_t *arec;
+ __uint32_t bno_btree_blkno;
+ __uint32_t cnt_btree_blkno;
+ struct xfs_btree_block *block;
+ int error;
+
+ bp = xfs_buf_get(mp->m_ddev_targp,
+ XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
+ XFS_FSS_TO_BB(mp, 1), 0);
+ if (!bp) {
+ error = ENOMEM;
+ goto error0;
+ }
+ agf = XFS_BUF_TO_AGF(bp);
+ be32_add_cpu(&agf->agf_length, -tsize);
+ be32_add_cpu(&agf->agf_freeblks, -tsize);
+ agf->agf_longest = agf->agf_freeblks;
+ bno_btree_blkno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_BNOi]);
+ cnt_btree_blkno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_CNTi]);
+ error = xfs_bwrite(bp);
+ xfs_buf_relse(bp);
+ if (error)
+ goto error0;
+
+ bp = xfs_buf_get(mp->m_ddev_targp,
+ XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
+ XFS_FSS_TO_BB(mp, 1), 0);
+ if (!bp) {
+ error = ENOMEM;
+ goto error0;
+ }
+ agi = XFS_BUF_TO_AGI(bp);
+ be32_add_cpu(&agi->agi_length, -tsize);
+ error = xfs_bwrite(bp);
+ xfs_buf_relse(bp);
+ if (error)
+ goto error0;
+
+ bp = xfs_buf_get(mp->m_ddev_targp,
+ XFS_AGB_TO_DADDR(mp, agno, bno_btree_blkno),
+ BTOBB(mp->m_sb.sb_blocksize), 0);
+ if (!bp) {
+ error = ENOMEM;
+ goto error0;
+ }
+ block = XFS_BUF_TO_BLOCK(bp);
+ arec = XFS_ALLOC_REC_ADDR(mp, block, 1);
+ be32_add_cpu(&arec->ar_blockcount, -tsize);
+ error = xfs_bwrite(bp);
+ xfs_buf_relse(bp);
+ if (error)
+ goto error0;
+
+ bp = xfs_buf_get(mp->m_ddev_targp,
+ XFS_AGB_TO_DADDR(mp, agno, cnt_btree_blkno),
+ BTOBB(mp->m_sb.sb_blocksize), 0);
+ if (!bp) {
+ error = ENOMEM;
+ goto error0;
+ }
+ block = XFS_BUF_TO_BLOCK(bp);
+ arec = XFS_ALLOC_REC_ADDR(mp, block, 1);
+ be32_add_cpu(&arec->ar_blockcount, -tsize);
+ error = xfs_bwrite(bp);
+ xfs_buf_relse(bp);
+ if (error)
+ goto error0;
+
+ pag = xfs_perag_get(mp, agno);
+ pag->pagf_freeblks -= tsize;
+ pag->pagf_longest = pag->pagf_freeblks;
+ xfs_perag_put(pag);
+
+ if (nfree)
+ *nfree = tsize;
+
+error0:
+ return error;
+}
+
+/*
* exported through ioctl XFS_IOC_FSCOUNTS
*/
--
1.7.4.1
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