/* * Copyright (c) 2014 Red Hat, Inc. * All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_shared.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_bit.h" #include "xfs_sb.h" #include "xfs_mount.h" #include "xfs_defer.h" #include "xfs_inode.h" #include "xfs_trans.h" #include "xfs_alloc.h" #include "xfs_btree.h" #include "xfs_rmap.h" #include "xfs_rmap_btree.h" #include "xfs_trace.h" #include "xfs_cksum.h" #include "xfs_error.h" #include "xfs_extent_busy.h" #include "xfs_ag_resv.h" /* * Reverse map btree. * * This is a per-ag tree used to track the owner(s) of a given extent. With * reflink it is possible for there to be multiple owners, which is a departure * from classic XFS. Owner records for data extents are inserted when the * extent is mapped and removed when an extent is unmapped. Owner records for * all other block types (i.e. metadata) are inserted when an extent is * allocated and removed when an extent is freed. There can only be one owner * of a metadata extent, usually an inode or some other metadata structure like * an AG btree. * * The rmap btree is part of the free space management, so blocks for the tree * are sourced from the agfl. Hence we need transaction reservation support for * this tree so that the freelist is always large enough. This also impacts on * the minimum space we need to leave free in the AG. * * The tree is ordered by [ag block, owner, offset]. This is a large key size, * but it is the only way to enforce unique keys when a block can be owned by * multiple files at any offset. There's no need to order/search by extent * size for online updating/management of the tree. It is intended that most * reverse lookups will be to find the owner(s) of a particular block, or to * try to recover tree and file data from corrupt primary metadata. */ static struct xfs_btree_cur * xfs_rmapbt_dup_cursor( struct xfs_btree_cur *cur) { return xfs_rmapbt_init_cursor(cur->bc_mp, cur->bc_tp, cur->bc_private.a.agbp, cur->bc_private.a.agno); } STATIC void xfs_rmapbt_set_root( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr, int inc) { struct xfs_buf *agbp = cur->bc_private.a.agbp; struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); xfs_agnumber_t seqno = be32_to_cpu(agf->agf_seqno); int btnum = cur->bc_btnum; struct xfs_perag *pag = xfs_perag_get(cur->bc_mp, seqno); ASSERT(ptr->s != 0); agf->agf_roots[btnum] = ptr->s; be32_add_cpu(&agf->agf_levels[btnum], inc); pag->pagf_levels[btnum] += inc; xfs_perag_put(pag); xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS); } STATIC int xfs_rmapbt_alloc_block( struct xfs_btree_cur *cur, union xfs_btree_ptr *start, union xfs_btree_ptr *new, int *stat) { struct xfs_buf *agbp = cur->bc_private.a.agbp; struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); int error; xfs_agblock_t bno; /* Allocate the new block from the freelist. If we can't, give up. */ error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp, &bno, 1); if (error) return error; trace_xfs_rmapbt_alloc_block(cur->bc_mp, cur->bc_private.a.agno, bno, 1); if (bno == NULLAGBLOCK) { *stat = 0; return 0; } xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1, false); xfs_trans_agbtree_delta(cur->bc_tp, 1); new->s = cpu_to_be32(bno); be32_add_cpu(&agf->agf_rmap_blocks, 1); xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS); xfs_ag_resv_rmapbt_alloc(cur->bc_mp, cur->bc_private.a.agno); *stat = 1; return 0; } STATIC int xfs_rmapbt_free_block( struct xfs_btree_cur *cur, struct xfs_buf *bp) { struct xfs_buf *agbp = cur->bc_private.a.agbp; struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); xfs_agblock_t bno; int error; bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp)); trace_xfs_rmapbt_free_block(cur->bc_mp, cur->bc_private.a.agno, bno, 1); be32_add_cpu(&agf->agf_rmap_blocks, -1); xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS); error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1); if (error) return error; xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1, XFS_EXTENT_BUSY_SKIP_DISCARD); xfs_trans_agbtree_delta(cur->bc_tp, -1); xfs_ag_resv_rmapbt_free(cur->bc_mp, cur->bc_private.a.agno); return 0; } STATIC int xfs_rmapbt_get_minrecs( struct xfs_btree_cur *cur, int level) { return cur->bc_mp->m_rmap_mnr[level != 0]; } STATIC int xfs_rmapbt_get_maxrecs( struct xfs_btree_cur *cur, int level) { return cur->bc_mp->m_rmap_mxr[level != 0]; } STATIC void xfs_rmapbt_init_key_from_rec( union xfs_btree_key *key, union xfs_btree_rec *rec) { key->rmap.rm_startblock = rec->rmap.rm_startblock; key->rmap.rm_owner = rec->rmap.rm_owner; key->rmap.rm_offset = rec->rmap.rm_offset; } /* * The high key for a reverse mapping record can be computed by shifting * the startblock and offset to the highest value that would still map * to that record. In practice this means that we add blockcount-1 to * the startblock for all records, and if the record is for a data/attr * fork mapping, we add blockcount-1 to the offset too. */ STATIC void xfs_rmapbt_init_high_key_from_rec( union xfs_btree_key *key, union xfs_btree_rec *rec) { uint64_t off; int adj; adj = be32_to_cpu(rec->rmap.rm_blockcount) - 1; key->rmap.rm_startblock = rec->rmap.rm_startblock; be32_add_cpu(&key->rmap.rm_startblock, adj); key->rmap.rm_owner = rec->rmap.rm_owner; key->rmap.rm_offset = rec->rmap.rm_offset; if (XFS_RMAP_NON_INODE_OWNER(be64_to_cpu(rec->rmap.rm_owner)) || XFS_RMAP_IS_BMBT_BLOCK(be64_to_cpu(rec->rmap.rm_offset))) return; off = be64_to_cpu(key->rmap.rm_offset); off = (XFS_RMAP_OFF(off) + adj) | (off & ~XFS_RMAP_OFF_MASK); key->rmap.rm_offset = cpu_to_be64(off); } STATIC void xfs_rmapbt_init_rec_from_cur( struct xfs_btree_cur *cur, union xfs_btree_rec *rec) { rec->rmap.rm_startblock = cpu_to_be32(cur->bc_rec.r.rm_startblock); rec->rmap.rm_blockcount = cpu_to_be32(cur->bc_rec.r.rm_blockcount); rec->rmap.rm_owner = cpu_to_be64(cur->bc_rec.r.rm_owner); rec->rmap.rm_offset = cpu_to_be64( xfs_rmap_irec_offset_pack(&cur->bc_rec.r)); } STATIC void xfs_rmapbt_init_ptr_from_cur( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr) { struct xfs_agf *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp); ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno)); ptr->s = agf->agf_roots[cur->bc_btnum]; } STATIC int64_t xfs_rmapbt_key_diff( struct xfs_btree_cur *cur, union xfs_btree_key *key) { struct xfs_rmap_irec *rec = &cur->bc_rec.r; struct xfs_rmap_key *kp = &key->rmap; __u64 x, y; int64_t d; d = (int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock; if (d) return d; x = be64_to_cpu(kp->rm_owner); y = rec->rm_owner; if (x > y) return 1; else if (y > x) return -1; x = XFS_RMAP_OFF(be64_to_cpu(kp->rm_offset)); y = rec->rm_offset; if (x > y) return 1; else if (y > x) return -1; return 0; } STATIC int64_t xfs_rmapbt_diff_two_keys( struct xfs_btree_cur *cur, union xfs_btree_key *k1, union xfs_btree_key *k2) { struct xfs_rmap_key *kp1 = &k1->rmap; struct xfs_rmap_key *kp2 = &k2->rmap; int64_t d; __u64 x, y; d = (int64_t)be32_to_cpu(kp1->rm_startblock) - be32_to_cpu(kp2->rm_startblock); if (d) return d; x = be64_to_cpu(kp1->rm_owner); y = be64_to_cpu(kp2->rm_owner); if (x > y) return 1; else if (y > x) return -1; x = XFS_RMAP_OFF(be64_to_cpu(kp1->rm_offset)); y = XFS_RMAP_OFF(be64_to_cpu(kp2->rm_offset)); if (x > y) return 1; else if (y > x) return -1; return 0; } static xfs_failaddr_t xfs_rmapbt_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_target->bt_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_perag *pag = bp->b_pag; xfs_failaddr_t fa; unsigned int level; /* * magic number and level verification * * During growfs operations, we can't verify the exact level or owner as * the perag is not fully initialised and hence not attached to the * buffer. In this case, check against the maximum tree depth. * * Similarly, during log recovery we will have a perag structure * attached, but the agf information will not yet have been initialised * from the on disk AGF. Again, we can only check against maximum limits * in this case. */ if (block->bb_magic != cpu_to_be32(XFS_RMAP_CRC_MAGIC)) return __this_address; if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) return __this_address; fa = xfs_btree_sblock_v5hdr_verify(bp); if (fa) return fa; level = be16_to_cpu(block->bb_level); if (pag && pag->pagf_init) { if (level >= pag->pagf_levels[XFS_BTNUM_RMAPi]) return __this_address; } else if (level >= mp->m_rmap_maxlevels) return __this_address; return xfs_btree_sblock_verify(bp, mp->m_rmap_mxr[level != 0]); } static void xfs_rmapbt_read_verify( struct xfs_buf *bp) { xfs_failaddr_t fa; if (!xfs_btree_sblock_verify_crc(bp)) xfs_verifier_error(bp, -EFSBADCRC, __this_address); else { fa = xfs_rmapbt_verify(bp); if (fa) xfs_verifier_error(bp, -EFSCORRUPTED, fa); } if (bp->b_error) trace_xfs_btree_corrupt(bp, _RET_IP_); } static void xfs_rmapbt_write_verify( struct xfs_buf *bp) { xfs_failaddr_t fa; fa = xfs_rmapbt_verify(bp); if (fa) { trace_xfs_btree_corrupt(bp, _RET_IP_); xfs_verifier_error(bp, -EFSCORRUPTED, fa); return; } xfs_btree_sblock_calc_crc(bp); } const struct xfs_buf_ops xfs_rmapbt_buf_ops = { .name = "xfs_rmapbt", .verify_read = xfs_rmapbt_read_verify, .verify_write = xfs_rmapbt_write_verify, .verify_struct = xfs_rmapbt_verify, }; STATIC int xfs_rmapbt_keys_inorder( struct xfs_btree_cur *cur, union xfs_btree_key *k1, union xfs_btree_key *k2) { uint32_t x; uint32_t y; uint64_t a; uint64_t b; x = be32_to_cpu(k1->rmap.rm_startblock); y = be32_to_cpu(k2->rmap.rm_startblock); if (x < y) return 1; else if (x > y) return 0; a = be64_to_cpu(k1->rmap.rm_owner); b = be64_to_cpu(k2->rmap.rm_owner); if (a < b) return 1; else if (a > b) return 0; a = XFS_RMAP_OFF(be64_to_cpu(k1->rmap.rm_offset)); b = XFS_RMAP_OFF(be64_to_cpu(k2->rmap.rm_offset)); if (a <= b) return 1; return 0; } STATIC int xfs_rmapbt_recs_inorder( struct xfs_btree_cur *cur, union xfs_btree_rec *r1, union xfs_btree_rec *r2) { uint32_t x; uint32_t y; uint64_t a; uint64_t b; x = be32_to_cpu(r1->rmap.rm_startblock); y = be32_to_cpu(r2->rmap.rm_startblock); if (x < y) return 1; else if (x > y) return 0; a = be64_to_cpu(r1->rmap.rm_owner); b = be64_to_cpu(r2->rmap.rm_owner); if (a < b) return 1; else if (a > b) return 0; a = XFS_RMAP_OFF(be64_to_cpu(r1->rmap.rm_offset)); b = XFS_RMAP_OFF(be64_to_cpu(r2->rmap.rm_offset)); if (a <= b) return 1; return 0; } static const struct xfs_btree_ops xfs_rmapbt_ops = { .rec_len = sizeof(struct xfs_rmap_rec), .key_len = 2 * sizeof(struct xfs_rmap_key), .dup_cursor = xfs_rmapbt_dup_cursor, .set_root = xfs_rmapbt_set_root, .alloc_block = xfs_rmapbt_alloc_block, .free_block = xfs_rmapbt_free_block, .get_minrecs = xfs_rmapbt_get_minrecs, .get_maxrecs = xfs_rmapbt_get_maxrecs, .init_key_from_rec = xfs_rmapbt_init_key_from_rec, .init_high_key_from_rec = xfs_rmapbt_init_high_key_from_rec, .init_rec_from_cur = xfs_rmapbt_init_rec_from_cur, .init_ptr_from_cur = xfs_rmapbt_init_ptr_from_cur, .key_diff = xfs_rmapbt_key_diff, .buf_ops = &xfs_rmapbt_buf_ops, .diff_two_keys = xfs_rmapbt_diff_two_keys, .keys_inorder = xfs_rmapbt_keys_inorder, .recs_inorder = xfs_rmapbt_recs_inorder, }; /* * Allocate a new allocation btree cursor. */ struct xfs_btree_cur * xfs_rmapbt_init_cursor( struct xfs_mount *mp, struct xfs_trans *tp, struct xfs_buf *agbp, xfs_agnumber_t agno) { struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); struct xfs_btree_cur *cur; cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_NOFS); cur->bc_tp = tp; cur->bc_mp = mp; /* Overlapping btree; 2 keys per pointer. */ cur->bc_btnum = XFS_BTNUM_RMAP; cur->bc_flags = XFS_BTREE_CRC_BLOCKS | XFS_BTREE_OVERLAPPING; cur->bc_blocklog = mp->m_sb.sb_blocklog; cur->bc_ops = &xfs_rmapbt_ops; cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]); cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_rmap_2); cur->bc_private.a.agbp = agbp; cur->bc_private.a.agno = agno; return cur; } /* * Calculate number of records in an rmap btree block. */ int xfs_rmapbt_maxrecs( int blocklen, int leaf) { blocklen -= XFS_RMAP_BLOCK_LEN; if (leaf) return blocklen / sizeof(struct xfs_rmap_rec); return blocklen / (2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t)); } /* Compute the maximum height of an rmap btree. */ void xfs_rmapbt_compute_maxlevels( struct xfs_mount *mp) { /* * On a non-reflink filesystem, the maximum number of rmap * records is the number of blocks in the AG, hence the max * rmapbt height is log_$maxrecs($agblocks). However, with * reflink each AG block can have up to 2^32 (per the refcount * record format) owners, which means that theoretically we * could face up to 2^64 rmap records. * * That effectively means that the max rmapbt height must be * XFS_BTREE_MAXLEVELS. "Fortunately" we'll run out of AG * blocks to feed the rmapbt long before the rmapbt reaches * maximum height. The reflink code uses ag_resv_critical to * disallow reflinking when less than 10% of the per-AG metadata * block reservation since the fallback is a regular file copy. */ if (xfs_sb_version_hasreflink(&mp->m_sb)) mp->m_rmap_maxlevels = XFS_BTREE_MAXLEVELS; else mp->m_rmap_maxlevels = xfs_btree_compute_maxlevels( mp->m_rmap_mnr, mp->m_sb.sb_agblocks); } /* Calculate the refcount btree size for some records. */ xfs_extlen_t xfs_rmapbt_calc_size( struct xfs_mount *mp, unsigned long long len) { return xfs_btree_calc_size(mp->m_rmap_mnr, len); } /* * Calculate the maximum refcount btree size. */ xfs_extlen_t xfs_rmapbt_max_size( struct xfs_mount *mp, xfs_agblock_t agblocks) { /* Bail out if we're uninitialized, which can happen in mkfs. */ if (mp->m_rmap_mxr[0] == 0) return 0; return xfs_rmapbt_calc_size(mp, agblocks); } /* * Figure out how many blocks to reserve and how many are used by this btree. */ int xfs_rmapbt_calc_reserves( struct xfs_mount *mp, xfs_agnumber_t agno, xfs_extlen_t *ask, xfs_extlen_t *used) { struct xfs_buf *agbp; struct xfs_agf *agf; xfs_agblock_t agblocks; xfs_extlen_t tree_len; int error; if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) return 0; error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); if (error) return error; agf = XFS_BUF_TO_AGF(agbp); agblocks = be32_to_cpu(agf->agf_length); tree_len = be32_to_cpu(agf->agf_rmap_blocks); xfs_buf_relse(agbp); /* Reserve 1% of the AG or enough for 1 block per record. */ *ask += max(agblocks / 100, xfs_rmapbt_max_size(mp, agblocks)); *used += tree_len; return error; }