diff options
Diffstat (limited to 'fs/erofs/zmap.c')
| -rw-r--r-- | fs/erofs/zmap.c | 810 |
1 files changed, 810 insertions, 0 deletions
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c new file mode 100644 index 000000000..0337b70b2 --- /dev/null +++ b/fs/erofs/zmap.c @@ -0,0 +1,810 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2018-2019 HUAWEI, Inc. + * https://www.huawei.com/ + */ +#include "internal.h" +#include <asm/unaligned.h> +#include <trace/events/erofs.h> + +static int z_erofs_do_map_blocks(struct inode *inode, + struct erofs_map_blocks *map, + int flags); + +int z_erofs_fill_inode(struct inode *inode) +{ + struct erofs_inode *const vi = EROFS_I(inode); + struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); + + if (!erofs_sb_has_big_pcluster(sbi) && + !erofs_sb_has_ztailpacking(sbi) && !erofs_sb_has_fragments(sbi) && + vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY) { + vi->z_advise = 0; + vi->z_algorithmtype[0] = 0; + vi->z_algorithmtype[1] = 0; + vi->z_logical_clusterbits = LOG_BLOCK_SIZE; + set_bit(EROFS_I_Z_INITED_BIT, &vi->flags); + } + inode->i_mapping->a_ops = &z_erofs_aops; + return 0; +} + +static int z_erofs_fill_inode_lazy(struct inode *inode) +{ + struct erofs_inode *const vi = EROFS_I(inode); + struct super_block *const sb = inode->i_sb; + int err, headnr; + erofs_off_t pos; + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + void *kaddr; + struct z_erofs_map_header *h; + + if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) { + /* + * paired with smp_mb() at the end of the function to ensure + * fields will only be observed after the bit is set. + */ + smp_mb(); + return 0; + } + + if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE)) + return -ERESTARTSYS; + + err = 0; + if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) + goto out_unlock; + + pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8); + kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), EROFS_KMAP); + if (IS_ERR(kaddr)) { + err = PTR_ERR(kaddr); + goto out_unlock; + } + + h = kaddr + erofs_blkoff(pos); + /* + * if the highest bit of the 8-byte map header is set, the whole file + * is stored in the packed inode. The rest bits keeps z_fragmentoff. + */ + if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) { + vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; + vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63); + vi->z_tailextent_headlcn = 0; + goto done; + } + vi->z_advise = le16_to_cpu(h->h_advise); + vi->z_algorithmtype[0] = h->h_algorithmtype & 15; + vi->z_algorithmtype[1] = h->h_algorithmtype >> 4; + + headnr = 0; + if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX || + vi->z_algorithmtype[++headnr] >= Z_EROFS_COMPRESSION_MAX) { + erofs_err(sb, "unknown HEAD%u format %u for nid %llu, please upgrade kernel", + headnr + 1, vi->z_algorithmtype[headnr], vi->nid); + err = -EOPNOTSUPP; + goto out_put_metabuf; + } + + vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7); + if (!erofs_sb_has_big_pcluster(EROFS_SB(sb)) && + vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 | + Z_EROFS_ADVISE_BIG_PCLUSTER_2)) { + erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu", + vi->nid); + err = -EFSCORRUPTED; + goto out_put_metabuf; + } + if (vi->datalayout == EROFS_INODE_FLAT_COMPRESSION && + !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^ + !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) { + erofs_err(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu", + vi->nid); + err = -EFSCORRUPTED; + goto out_put_metabuf; + } + + if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) { + struct erofs_map_blocks map = { + .buf = __EROFS_BUF_INITIALIZER + }; + + vi->z_idata_size = le16_to_cpu(h->h_idata_size); + err = z_erofs_do_map_blocks(inode, &map, + EROFS_GET_BLOCKS_FINDTAIL); + erofs_put_metabuf(&map.buf); + + if (!map.m_plen || + erofs_blkoff(map.m_pa) + map.m_plen > EROFS_BLKSIZ) { + erofs_err(sb, "invalid tail-packing pclustersize %llu", + map.m_plen); + err = -EFSCORRUPTED; + } + if (err < 0) + goto out_put_metabuf; + } + + if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER && + !(h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT)) { + struct erofs_map_blocks map = { + .buf = __EROFS_BUF_INITIALIZER + }; + + vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff); + err = z_erofs_do_map_blocks(inode, &map, + EROFS_GET_BLOCKS_FINDTAIL); + erofs_put_metabuf(&map.buf); + if (err < 0) + goto out_put_metabuf; + } +done: + /* paired with smp_mb() at the beginning of the function */ + smp_mb(); + set_bit(EROFS_I_Z_INITED_BIT, &vi->flags); +out_put_metabuf: + erofs_put_metabuf(&buf); +out_unlock: + clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags); + return err; +} + +struct z_erofs_maprecorder { + struct inode *inode; + struct erofs_map_blocks *map; + void *kaddr; + + unsigned long lcn; + /* compression extent information gathered */ + u8 type, headtype; + u16 clusterofs; + u16 delta[2]; + erofs_blk_t pblk, compressedblks; + erofs_off_t nextpackoff; + bool partialref; +}; + +static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m, + unsigned long lcn) +{ + struct inode *const inode = m->inode; + struct erofs_inode *const vi = EROFS_I(inode); + const erofs_off_t pos = + Z_EROFS_VLE_LEGACY_INDEX_ALIGN(erofs_iloc(inode) + + vi->inode_isize + vi->xattr_isize) + + lcn * sizeof(struct z_erofs_vle_decompressed_index); + struct z_erofs_vle_decompressed_index *di; + unsigned int advise, type; + + m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb, + erofs_blknr(pos), EROFS_KMAP_ATOMIC); + if (IS_ERR(m->kaddr)) + return PTR_ERR(m->kaddr); + + m->nextpackoff = pos + sizeof(struct z_erofs_vle_decompressed_index); + m->lcn = lcn; + di = m->kaddr + erofs_blkoff(pos); + + advise = le16_to_cpu(di->di_advise); + type = (advise >> Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT) & + ((1 << Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) - 1); + switch (type) { + case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: + m->clusterofs = 1 << vi->z_logical_clusterbits; + m->delta[0] = le16_to_cpu(di->di_u.delta[0]); + if (m->delta[0] & Z_EROFS_VLE_DI_D0_CBLKCNT) { + if (!(vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 | + Z_EROFS_ADVISE_BIG_PCLUSTER_2))) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + m->compressedblks = m->delta[0] & + ~Z_EROFS_VLE_DI_D0_CBLKCNT; + m->delta[0] = 1; + } + m->delta[1] = le16_to_cpu(di->di_u.delta[1]); + break; + case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD1: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2: + if (advise & Z_EROFS_VLE_DI_PARTIAL_REF) + m->partialref = true; + m->clusterofs = le16_to_cpu(di->di_clusterofs); + if (m->clusterofs >= 1 << vi->z_logical_clusterbits) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + m->pblk = le32_to_cpu(di->di_u.blkaddr); + break; + default: + DBG_BUGON(1); + return -EOPNOTSUPP; + } + m->type = type; + return 0; +} + +static unsigned int decode_compactedbits(unsigned int lobits, + unsigned int lomask, + u8 *in, unsigned int pos, u8 *type) +{ + const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7); + const unsigned int lo = v & lomask; + + *type = (v >> lobits) & 3; + return lo; +} + +static int get_compacted_la_distance(unsigned int lclusterbits, + unsigned int encodebits, + unsigned int vcnt, u8 *in, int i) +{ + const unsigned int lomask = (1 << lclusterbits) - 1; + unsigned int lo, d1 = 0; + u8 type; + + DBG_BUGON(i >= vcnt); + + do { + lo = decode_compactedbits(lclusterbits, lomask, + in, encodebits * i, &type); + + if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) + return d1; + ++d1; + } while (++i < vcnt); + + /* vcnt - 1 (Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) item */ + if (!(lo & Z_EROFS_VLE_DI_D0_CBLKCNT)) + d1 += lo - 1; + return d1; +} + +static int unpack_compacted_index(struct z_erofs_maprecorder *m, + unsigned int amortizedshift, + erofs_off_t pos, bool lookahead) +{ + struct erofs_inode *const vi = EROFS_I(m->inode); + const unsigned int lclusterbits = vi->z_logical_clusterbits; + const unsigned int lomask = (1 << lclusterbits) - 1; + unsigned int vcnt, base, lo, encodebits, nblk, eofs; + int i; + u8 *in, type; + bool big_pcluster; + + if (1 << amortizedshift == 4 && lclusterbits <= 14) + vcnt = 2; + else if (1 << amortizedshift == 2 && lclusterbits == 12) + vcnt = 16; + else + return -EOPNOTSUPP; + + /* it doesn't equal to round_up(..) */ + m->nextpackoff = round_down(pos, vcnt << amortizedshift) + + (vcnt << amortizedshift); + big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1; + encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt; + eofs = erofs_blkoff(pos); + base = round_down(eofs, vcnt << amortizedshift); + in = m->kaddr + base; + + i = (eofs - base) >> amortizedshift; + + lo = decode_compactedbits(lclusterbits, lomask, + in, encodebits * i, &type); + m->type = type; + if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) { + m->clusterofs = 1 << lclusterbits; + + /* figure out lookahead_distance: delta[1] if needed */ + if (lookahead) + m->delta[1] = get_compacted_la_distance(lclusterbits, + encodebits, vcnt, in, i); + if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) { + if (!big_pcluster) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + m->compressedblks = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT; + m->delta[0] = 1; + return 0; + } else if (i + 1 != (int)vcnt) { + m->delta[0] = lo; + return 0; + } + /* + * since the last lcluster in the pack is special, + * of which lo saves delta[1] rather than delta[0]. + * Hence, get delta[0] by the previous lcluster indirectly. + */ + lo = decode_compactedbits(lclusterbits, lomask, + in, encodebits * (i - 1), &type); + if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) + lo = 0; + else if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) + lo = 1; + m->delta[0] = lo + 1; + return 0; + } + m->clusterofs = lo; + m->delta[0] = 0; + /* figout out blkaddr (pblk) for HEAD lclusters */ + if (!big_pcluster) { + nblk = 1; + while (i > 0) { + --i; + lo = decode_compactedbits(lclusterbits, lomask, + in, encodebits * i, &type); + if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) + i -= lo; + + if (i >= 0) + ++nblk; + } + } else { + nblk = 0; + while (i > 0) { + --i; + lo = decode_compactedbits(lclusterbits, lomask, + in, encodebits * i, &type); + if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) { + if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) { + --i; + nblk += lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT; + continue; + } + /* bigpcluster shouldn't have plain d0 == 1 */ + if (lo <= 1) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + i -= lo - 2; + continue; + } + ++nblk; + } + } + in += (vcnt << amortizedshift) - sizeof(__le32); + m->pblk = le32_to_cpu(*(__le32 *)in) + nblk; + return 0; +} + +static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m, + unsigned long lcn, bool lookahead) +{ + struct inode *const inode = m->inode; + struct erofs_inode *const vi = EROFS_I(inode); + const erofs_off_t ebase = sizeof(struct z_erofs_map_header) + + ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8); + const unsigned int totalidx = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ); + unsigned int compacted_4b_initial, compacted_2b; + unsigned int amortizedshift; + erofs_off_t pos; + + if (lcn >= totalidx) + return -EINVAL; + + m->lcn = lcn; + /* used to align to 32-byte (compacted_2b) alignment */ + compacted_4b_initial = (32 - ebase % 32) / 4; + if (compacted_4b_initial == 32 / 4) + compacted_4b_initial = 0; + + if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) && + compacted_4b_initial < totalidx) + compacted_2b = rounddown(totalidx - compacted_4b_initial, 16); + else + compacted_2b = 0; + + pos = ebase; + if (lcn < compacted_4b_initial) { + amortizedshift = 2; + goto out; + } + pos += compacted_4b_initial * 4; + lcn -= compacted_4b_initial; + + if (lcn < compacted_2b) { + amortizedshift = 1; + goto out; + } + pos += compacted_2b * 2; + lcn -= compacted_2b; + amortizedshift = 2; +out: + pos += lcn * (1 << amortizedshift); + m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb, + erofs_blknr(pos), EROFS_KMAP_ATOMIC); + if (IS_ERR(m->kaddr)) + return PTR_ERR(m->kaddr); + return unpack_compacted_index(m, amortizedshift, pos, lookahead); +} + +static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m, + unsigned int lcn, bool lookahead) +{ + const unsigned int datamode = EROFS_I(m->inode)->datalayout; + + if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY) + return legacy_load_cluster_from_disk(m, lcn); + + if (datamode == EROFS_INODE_FLAT_COMPRESSION) + return compacted_load_cluster_from_disk(m, lcn, lookahead); + + return -EINVAL; +} + +static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, + unsigned int lookback_distance) +{ + struct erofs_inode *const vi = EROFS_I(m->inode); + const unsigned int lclusterbits = vi->z_logical_clusterbits; + + while (m->lcn >= lookback_distance) { + unsigned long lcn = m->lcn - lookback_distance; + int err; + + /* load extent head logical cluster if needed */ + err = z_erofs_load_cluster_from_disk(m, lcn, false); + if (err) + return err; + + switch (m->type) { + case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: + if (!m->delta[0]) { + erofs_err(m->inode->i_sb, + "invalid lookback distance 0 @ nid %llu", + vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } + lookback_distance = m->delta[0]; + continue; + case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD1: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2: + m->headtype = m->type; + m->map->m_la = (lcn << lclusterbits) | m->clusterofs; + return 0; + default: + erofs_err(m->inode->i_sb, + "unknown type %u @ lcn %lu of nid %llu", + m->type, lcn, vi->nid); + DBG_BUGON(1); + return -EOPNOTSUPP; + } + } + + erofs_err(m->inode->i_sb, "bogus lookback distance @ nid %llu", + vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; +} + +static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, + unsigned int initial_lcn) +{ + struct erofs_inode *const vi = EROFS_I(m->inode); + struct erofs_map_blocks *const map = m->map; + const unsigned int lclusterbits = vi->z_logical_clusterbits; + unsigned long lcn; + int err; + + DBG_BUGON(m->type != Z_EROFS_VLE_CLUSTER_TYPE_PLAIN && + m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD1 && + m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD2); + DBG_BUGON(m->type != m->headtype); + + if (m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN || + ((m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD1) && + !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) || + ((m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) && + !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2))) { + map->m_plen = 1ULL << lclusterbits; + return 0; + } + lcn = m->lcn + 1; + if (m->compressedblks) + goto out; + + err = z_erofs_load_cluster_from_disk(m, lcn, false); + if (err) + return err; + + /* + * If the 1st NONHEAD lcluster has already been handled initially w/o + * valid compressedblks, which means at least it mustn't be CBLKCNT, or + * an internal implemenatation error is detected. + * + * The following code can also handle it properly anyway, but let's + * BUG_ON in the debugging mode only for developers to notice that. + */ + DBG_BUGON(lcn == initial_lcn && + m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD); + + switch (m->type) { + case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD1: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2: + /* + * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type + * rather than CBLKCNT, it's a 1 lcluster-sized pcluster. + */ + m->compressedblks = 1 << (lclusterbits - LOG_BLOCK_SIZE); + break; + case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: + if (m->delta[0] != 1) + goto err_bonus_cblkcnt; + if (m->compressedblks) + break; + fallthrough; + default: + erofs_err(m->inode->i_sb, + "cannot found CBLKCNT @ lcn %lu of nid %llu", + lcn, vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } +out: + map->m_plen = (u64)m->compressedblks << LOG_BLOCK_SIZE; + return 0; +err_bonus_cblkcnt: + erofs_err(m->inode->i_sb, + "bogus CBLKCNT @ lcn %lu of nid %llu", + lcn, vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; +} + +static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m) +{ + struct inode *inode = m->inode; + struct erofs_inode *vi = EROFS_I(inode); + struct erofs_map_blocks *map = m->map; + unsigned int lclusterbits = vi->z_logical_clusterbits; + u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits; + int err; + + do { + /* handle the last EOF pcluster (no next HEAD lcluster) */ + if ((lcn << lclusterbits) >= inode->i_size) { + map->m_llen = inode->i_size - map->m_la; + return 0; + } + + err = z_erofs_load_cluster_from_disk(m, lcn, true); + if (err) + return err; + + if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) { + DBG_BUGON(!m->delta[1] && + m->clusterofs != 1 << lclusterbits); + } else if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN || + m->type == Z_EROFS_VLE_CLUSTER_TYPE_HEAD1 || + m->type == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) { + /* go on until the next HEAD lcluster */ + if (lcn != headlcn) + break; + m->delta[1] = 1; + } else { + erofs_err(inode->i_sb, "unknown type %u @ lcn %llu of nid %llu", + m->type, lcn, vi->nid); + DBG_BUGON(1); + return -EOPNOTSUPP; + } + lcn += m->delta[1]; + } while (m->delta[1]); + + map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la; + return 0; +} + +static int z_erofs_do_map_blocks(struct inode *inode, + struct erofs_map_blocks *map, + int flags) +{ + struct erofs_inode *const vi = EROFS_I(inode); + bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER; + bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; + struct z_erofs_maprecorder m = { + .inode = inode, + .map = map, + }; + int err = 0; + unsigned int lclusterbits, endoff; + unsigned long initial_lcn; + unsigned long long ofs, end; + + lclusterbits = vi->z_logical_clusterbits; + ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? inode->i_size - 1 : map->m_la; + initial_lcn = ofs >> lclusterbits; + endoff = ofs & ((1 << lclusterbits) - 1); + + err = z_erofs_load_cluster_from_disk(&m, initial_lcn, false); + if (err) + goto unmap_out; + + if (ztailpacking && (flags & EROFS_GET_BLOCKS_FINDTAIL)) + vi->z_idataoff = m.nextpackoff; + + map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED; + end = (m.lcn + 1ULL) << lclusterbits; + + switch (m.type) { + case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD1: + case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2: + if (endoff >= m.clusterofs) { + m.headtype = m.type; + map->m_la = (m.lcn << lclusterbits) | m.clusterofs; + /* + * For ztailpacking files, in order to inline data more + * effectively, special EOF lclusters are now supported + * which can have three parts at most. + */ + if (ztailpacking && end > inode->i_size) + end = inode->i_size; + break; + } + /* m.lcn should be >= 1 if endoff < m.clusterofs */ + if (!m.lcn) { + erofs_err(inode->i_sb, + "invalid logical cluster 0 at nid %llu", + vi->nid); + err = -EFSCORRUPTED; + goto unmap_out; + } + end = (m.lcn << lclusterbits) | m.clusterofs; + map->m_flags |= EROFS_MAP_FULL_MAPPED; + m.delta[0] = 1; + fallthrough; + case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: + /* get the corresponding first chunk */ + err = z_erofs_extent_lookback(&m, m.delta[0]); + if (err) + goto unmap_out; + break; + default: + erofs_err(inode->i_sb, + "unknown type %u @ offset %llu of nid %llu", + m.type, ofs, vi->nid); + err = -EOPNOTSUPP; + goto unmap_out; + } + if (m.partialref) + map->m_flags |= EROFS_MAP_PARTIAL_REF; + map->m_llen = end - map->m_la; + + if (flags & EROFS_GET_BLOCKS_FINDTAIL) { + vi->z_tailextent_headlcn = m.lcn; + /* for non-compact indexes, fragmentoff is 64 bits */ + if (fragment && + vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY) + vi->z_fragmentoff |= (u64)m.pblk << 32; + } + if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) { + map->m_flags |= EROFS_MAP_META; + map->m_pa = vi->z_idataoff; + map->m_plen = vi->z_idata_size; + } else if (fragment && m.lcn == vi->z_tailextent_headlcn) { + map->m_flags |= EROFS_MAP_FRAGMENT; + } else { + map->m_pa = blknr_to_addr(m.pblk); + err = z_erofs_get_extent_compressedlen(&m, initial_lcn); + if (err) + goto unmap_out; + } + + if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) { + if (map->m_llen > map->m_plen) { + DBG_BUGON(1); + err = -EFSCORRUPTED; + goto unmap_out; + } + if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER) + map->m_algorithmformat = + Z_EROFS_COMPRESSION_INTERLACED; + else + map->m_algorithmformat = + Z_EROFS_COMPRESSION_SHIFTED; + } else if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) { + map->m_algorithmformat = vi->z_algorithmtype[1]; + } else { + map->m_algorithmformat = vi->z_algorithmtype[0]; + } + + if ((flags & EROFS_GET_BLOCKS_FIEMAP) || + ((flags & EROFS_GET_BLOCKS_READMORE) && + map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA && + map->m_llen >= EROFS_BLKSIZ)) { + err = z_erofs_get_extent_decompressedlen(&m); + if (!err) + map->m_flags |= EROFS_MAP_FULL_MAPPED; + } + +unmap_out: + erofs_unmap_metabuf(&m.map->buf); + erofs_dbg("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o", + __func__, map->m_la, map->m_pa, + map->m_llen, map->m_plen, map->m_flags); + return err; +} + +int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map, + int flags) +{ + struct erofs_inode *const vi = EROFS_I(inode); + int err = 0; + + trace_z_erofs_map_blocks_iter_enter(inode, map, flags); + + /* when trying to read beyond EOF, leave it unmapped */ + if (map->m_la >= inode->i_size) { + map->m_llen = map->m_la + 1 - inode->i_size; + map->m_la = inode->i_size; + map->m_flags = 0; + goto out; + } + + err = z_erofs_fill_inode_lazy(inode); + if (err) + goto out; + + if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) && + !vi->z_tailextent_headlcn) { + map->m_la = 0; + map->m_llen = inode->i_size; + map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_FULL_MAPPED | + EROFS_MAP_FRAGMENT; + goto out; + } + + err = z_erofs_do_map_blocks(inode, map, flags); +out: + trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err); + + /* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */ + DBG_BUGON(err < 0 && err != -ENOMEM); + return err; +} + +static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset, + loff_t length, unsigned int flags, + struct iomap *iomap, struct iomap *srcmap) +{ + int ret; + struct erofs_map_blocks map = { .m_la = offset }; + + ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP); + erofs_put_metabuf(&map.buf); + if (ret < 0) + return ret; + + iomap->bdev = inode->i_sb->s_bdev; + iomap->offset = map.m_la; + iomap->length = map.m_llen; + if (map.m_flags & EROFS_MAP_MAPPED) { + iomap->type = IOMAP_MAPPED; + iomap->addr = map.m_flags & EROFS_MAP_FRAGMENT ? + IOMAP_NULL_ADDR : map.m_pa; + } else { + iomap->type = IOMAP_HOLE; + iomap->addr = IOMAP_NULL_ADDR; + /* + * No strict rule on how to describe extents for post EOF, yet + * we need to do like below. Otherwise, iomap itself will get + * into an endless loop on post EOF. + * + * Calculate the effective offset by subtracting extent start + * (map.m_la) from the requested offset, and add it to length. + * (NB: offset >= map.m_la always) + */ + if (iomap->offset >= inode->i_size) + iomap->length = length + offset - map.m_la; + } + iomap->flags = 0; + return 0; +} + +const struct iomap_ops z_erofs_iomap_report_ops = { + .iomap_begin = z_erofs_iomap_begin_report, +}; |