diff options
Diffstat (limited to 'fs/erofs/zmap.c')
| -rw-r--r-- | fs/erofs/zmap.c | 808 |
1 files changed, 808 insertions, 0 deletions
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c new file mode 100644 index 000000000000..c8d8e129eb4b --- /dev/null +++ b/fs/erofs/zmap.c @@ -0,0 +1,808 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2018-2019 HUAWEI, Inc. + * https://www.huawei.com/ + */ +#include "internal.h" +#include <linux/unaligned.h> +#include <trace/events/erofs.h> + +struct z_erofs_maprecorder { + struct inode *inode; + struct erofs_map_blocks *map; + 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, in_mbox; +}; + +static int z_erofs_load_full_lcluster(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_FULL_INDEX_START(erofs_iloc(inode) + + vi->inode_isize + vi->xattr_isize) + + lcn * sizeof(struct z_erofs_lcluster_index); + struct z_erofs_lcluster_index *di; + unsigned int advise; + + di = erofs_read_metabuf(&m->map->buf, inode->i_sb, pos, m->in_mbox); + if (IS_ERR(di)) + return PTR_ERR(di); + m->lcn = lcn; + m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index); + + advise = le16_to_cpu(di->di_advise); + m->type = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK; + if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { + m->clusterofs = 1 << vi->z_lclusterbits; + m->delta[0] = le16_to_cpu(di->di_u.delta[0]); + if (m->delta[0] & Z_EROFS_LI_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_LI_D0_CBLKCNT; + m->delta[0] = 1; + } + m->delta[1] = le16_to_cpu(di->di_u.delta[1]); + } else { + m->partialref = !!(advise & Z_EROFS_LI_PARTIAL_REF); + m->clusterofs = le16_to_cpu(di->di_clusterofs); + m->pblk = le32_to_cpu(di->di_u.blkaddr); + } + return 0; +} + +static unsigned int decode_compactedbits(unsigned int lobits, + u8 *in, unsigned int pos, u8 *type) +{ + const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7); + const unsigned int lo = v & ((1 << lobits) - 1); + + *type = (v >> lobits) & 3; + return lo; +} + +static int get_compacted_la_distance(unsigned int lobits, + unsigned int encodebits, + unsigned int vcnt, u8 *in, int i) +{ + unsigned int lo, d1 = 0; + u8 type; + + DBG_BUGON(i >= vcnt); + + do { + lo = decode_compactedbits(lobits, in, encodebits * i, &type); + + if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) + return d1; + ++d1; + } while (++i < vcnt); + + /* vcnt - 1 (Z_EROFS_LCLUSTER_TYPE_NONHEAD) item */ + if (!(lo & Z_EROFS_LI_D0_CBLKCNT)) + d1 += lo - 1; + return d1; +} + +static int z_erofs_load_compact_lcluster(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 = Z_EROFS_MAP_HEADER_END(erofs_iloc(inode) + + vi->inode_isize + vi->xattr_isize); + const unsigned int lclusterbits = vi->z_lclusterbits; + const unsigned int totalidx = erofs_iblks(inode); + unsigned int compacted_4b_initial, compacted_2b, amortizedshift; + unsigned int vcnt, lo, lobits, encodebits, nblk, bytes; + bool big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1; + erofs_off_t pos; + u8 *in, type; + int i; + + if (lcn >= totalidx || lclusterbits > 14) + return -EINVAL; + + m->lcn = lcn; + /* used to align to 32-byte (compacted_2b) alignment */ + compacted_4b_initial = ((32 - ebase % 32) / 4) & 7; + compacted_2b = 0; + if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) && + compacted_4b_initial < totalidx) + compacted_2b = rounddown(totalidx - compacted_4b_initial, 16); + + pos = ebase; + amortizedshift = 2; /* compact_4b */ + if (lcn >= compacted_4b_initial) { + pos += compacted_4b_initial * 4; + lcn -= compacted_4b_initial; + if (lcn < compacted_2b) { + amortizedshift = 1; + } else { + pos += compacted_2b * 2; + lcn -= compacted_2b; + } + } + pos += lcn * (1 << amortizedshift); + + /* figure out the lcluster count in this pack */ + if (1 << amortizedshift == 4 && lclusterbits <= 14) + vcnt = 2; + else if (1 << amortizedshift == 2 && lclusterbits <= 12) + vcnt = 16; + else + return -EOPNOTSUPP; + + in = erofs_read_metabuf(&m->map->buf, inode->i_sb, pos, m->in_mbox); + if (IS_ERR(in)) + return PTR_ERR(in); + + /* it doesn't equal to round_up(..) */ + m->nextpackoff = round_down(pos, vcnt << amortizedshift) + + (vcnt << amortizedshift); + lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U); + encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt; + bytes = pos & ((vcnt << amortizedshift) - 1); + in -= bytes; + i = bytes >> amortizedshift; + + lo = decode_compactedbits(lobits, in, encodebits * i, &type); + m->type = type; + if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { + m->clusterofs = 1 << lclusterbits; + + /* figure out lookahead_distance: delta[1] if needed */ + if (lookahead) + m->delta[1] = get_compacted_la_distance(lobits, + encodebits, vcnt, in, i); + if (lo & Z_EROFS_LI_D0_CBLKCNT) { + if (!big_pcluster) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + m->compressedblks = lo & ~Z_EROFS_LI_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(lobits, in, + encodebits * (i - 1), &type); + if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) + lo = 0; + else if (lo & Z_EROFS_LI_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(lobits, in, + encodebits * i, &type); + if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) + i -= lo; + + if (i >= 0) + ++nblk; + } + } else { + nblk = 0; + while (i > 0) { + --i; + lo = decode_compactedbits(lobits, in, + encodebits * i, &type); + if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { + if (lo & Z_EROFS_LI_D0_CBLKCNT) { + --i; + nblk += lo & ~Z_EROFS_LI_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 z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m, + unsigned int lcn, bool lookahead) +{ + struct erofs_inode *vi = EROFS_I(m->inode); + int err; + + if (vi->datalayout == EROFS_INODE_COMPRESSED_COMPACT) { + err = z_erofs_load_compact_lcluster(m, lcn, lookahead); + } else { + DBG_BUGON(vi->datalayout != EROFS_INODE_COMPRESSED_FULL); + err = z_erofs_load_full_lcluster(m, lcn); + } + if (err) + return err; + + if (m->type >= Z_EROFS_LCLUSTER_TYPE_MAX) { + erofs_err(m->inode->i_sb, "unknown type %u @ lcn %u of nid %llu", + m->type, lcn, EROFS_I(m->inode)->nid); + DBG_BUGON(1); + return -EOPNOTSUPP; + } else if (m->type != Z_EROFS_LCLUSTER_TYPE_NONHEAD && + m->clusterofs >= (1 << vi->z_lclusterbits)) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + return 0; +} + +static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, + unsigned int lookback_distance) +{ + struct super_block *sb = m->inode->i_sb; + struct erofs_inode *const vi = EROFS_I(m->inode); + const unsigned int lclusterbits = vi->z_lclusterbits; + + while (m->lcn >= lookback_distance) { + unsigned long lcn = m->lcn - lookback_distance; + int err; + + if (!lookback_distance) + break; + + err = z_erofs_load_lcluster_from_disk(m, lcn, false); + if (err) + return err; + if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { + lookback_distance = m->delta[0]; + continue; + } + m->headtype = m->type; + m->map->m_la = (lcn << lclusterbits) | m->clusterofs; + return 0; + } + erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu", + lookback_distance, m->lcn, vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; +} + +static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, + unsigned int initial_lcn) +{ + struct inode *inode = m->inode; + struct super_block *sb = inode->i_sb; + struct erofs_inode *vi = EROFS_I(inode); + bool bigpcl1 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1; + bool bigpcl2 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2; + unsigned long lcn = m->lcn + 1; + int err; + + DBG_BUGON(m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD); + DBG_BUGON(m->type != m->headtype); + + if ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD1 && !bigpcl1) || + ((m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN || + m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) && !bigpcl2) || + (lcn << vi->z_lclusterbits) >= inode->i_size) + m->compressedblks = 1; + + if (m->compressedblks) + goto out; + + err = z_erofs_load_lcluster_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_LCLUSTER_TYPE_NONHEAD); + + if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD && m->delta[0] != 1) { + erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } + + /* + * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type rather + * than CBLKCNT, it's a 1 block-sized pcluster. + */ + if (m->type != Z_EROFS_LCLUSTER_TYPE_NONHEAD || !m->compressedblks) + m->compressedblks = 1; +out: + m->map->m_plen = erofs_pos(sb, m->compressedblks); + return 0; +} + +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_lclusterbits; + u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits; + int err; + + while (1) { + /* 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_lcluster_from_disk(m, lcn, true); + if (err) + return err; + + if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { + /* work around invalid d1 generated by pre-1.0 mkfs */ + if (unlikely(!m->delta[1])) { + m->delta[1] = 1; + DBG_BUGON(1); + } + } else if (m->type < Z_EROFS_LCLUSTER_TYPE_MAX) { + if (lcn != headlcn) + break; /* ends at the next HEAD lcluster */ + m->delta[1] = 1; + } + lcn += m->delta[1]; + } + map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la; + return 0; +} + +static int z_erofs_map_blocks_fo(struct inode *inode, + struct erofs_map_blocks *map, int flags) +{ + struct erofs_inode *vi = EROFS_I(inode); + struct super_block *sb = inode->i_sb; + bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; + bool ztailpacking = vi->z_idata_size; + unsigned int lclusterbits = vi->z_lclusterbits; + struct z_erofs_maprecorder m = { + .inode = inode, + .map = map, + .in_mbox = erofs_inode_in_metabox(inode), + }; + unsigned int endoff; + unsigned long initial_lcn; + unsigned long long ofs, end; + int err; + + ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? inode->i_size - 1 : map->m_la; + if (fragment && !(flags & EROFS_GET_BLOCKS_FINDTAIL) && + !vi->z_tailextent_headlcn) { + map->m_la = 0; + map->m_llen = inode->i_size; + map->m_flags = EROFS_MAP_FRAGMENT; + return 0; + } + initial_lcn = ofs >> lclusterbits; + endoff = ofs & ((1 << lclusterbits) - 1); + + err = z_erofs_load_lcluster_from_disk(&m, initial_lcn, false); + if (err) + goto unmap_out; + + if ((flags & EROFS_GET_BLOCKS_FINDTAIL) && ztailpacking) + vi->z_fragmentoff = m.nextpackoff; + map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED; + end = (m.lcn + 1ULL) << lclusterbits; + + if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD && 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; + } else { + if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) { + end = (m.lcn << lclusterbits) | m.clusterofs; + map->m_flags |= EROFS_MAP_FULL_MAPPED; + m.delta[0] = 1; + } + /* get the corresponding first chunk */ + err = z_erofs_extent_lookback(&m, m.delta[0]); + if (err) + 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_COMPRESSED_FULL) + 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_fragmentoff; + map->m_plen = vi->z_idata_size; + if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) { + erofs_err(sb, "ztailpacking inline data across blocks @ nid %llu", + vi->nid); + err = -EFSCORRUPTED; + goto unmap_out; + } + } else if (fragment && m.lcn == vi->z_tailextent_headlcn) { + map->m_flags = EROFS_MAP_FRAGMENT; + } else { + map->m_pa = erofs_pos(sb, m.pblk); + err = z_erofs_get_extent_compressedlen(&m, initial_lcn); + if (err) + goto unmap_out; + } + + if (m.headtype == Z_EROFS_LCLUSTER_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_LCLUSTER_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_algorithmformat == Z_EROFS_COMPRESSION_DEFLATE || + map->m_algorithmformat == Z_EROFS_COMPRESSION_ZSTD) && + map->m_llen >= i_blocksize(inode))) { + err = z_erofs_get_extent_decompressedlen(&m); + if (!err) + map->m_flags |= EROFS_MAP_FULL_MAPPED; + } + +unmap_out: + erofs_unmap_metabuf(&m.map->buf); + return err; +} + +static int z_erofs_map_blocks_ext(struct inode *inode, + struct erofs_map_blocks *map, int flags) +{ + struct erofs_inode *vi = EROFS_I(inode); + struct super_block *sb = inode->i_sb; + bool interlaced = vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER; + unsigned int recsz = z_erofs_extent_recsize(vi->z_advise); + erofs_off_t pos = round_up(Z_EROFS_MAP_HEADER_END(erofs_iloc(inode) + + vi->inode_isize + vi->xattr_isize), recsz); + bool in_mbox = erofs_inode_in_metabox(inode); + erofs_off_t lend = inode->i_size; + erofs_off_t l, r, mid, pa, la, lstart; + struct z_erofs_extent *ext; + unsigned int fmt; + bool last; + + map->m_flags = 0; + if (recsz <= offsetof(struct z_erofs_extent, pstart_hi)) { + if (recsz <= offsetof(struct z_erofs_extent, pstart_lo)) { + ext = erofs_read_metabuf(&map->buf, sb, pos, in_mbox); + if (IS_ERR(ext)) + return PTR_ERR(ext); + pa = le64_to_cpu(*(__le64 *)ext); + pos += sizeof(__le64); + lstart = 0; + } else { + lstart = round_down(map->m_la, 1 << vi->z_lclusterbits); + pos += (lstart >> vi->z_lclusterbits) * recsz; + pa = EROFS_NULL_ADDR; + } + + for (; lstart <= map->m_la; lstart += 1 << vi->z_lclusterbits) { + ext = erofs_read_metabuf(&map->buf, sb, pos, in_mbox); + if (IS_ERR(ext)) + return PTR_ERR(ext); + map->m_plen = le32_to_cpu(ext->plen); + if (pa != EROFS_NULL_ADDR) { + map->m_pa = pa; + pa += map->m_plen & Z_EROFS_EXTENT_PLEN_MASK; + } else { + map->m_pa = le32_to_cpu(ext->pstart_lo); + } + pos += recsz; + } + last = (lstart >= round_up(lend, 1 << vi->z_lclusterbits)); + lend = min(lstart, lend); + lstart -= 1 << vi->z_lclusterbits; + } else { + lstart = lend; + for (l = 0, r = vi->z_extents; l < r; ) { + mid = l + (r - l) / 2; + ext = erofs_read_metabuf(&map->buf, sb, + pos + mid * recsz, in_mbox); + if (IS_ERR(ext)) + return PTR_ERR(ext); + + la = le32_to_cpu(ext->lstart_lo); + pa = le32_to_cpu(ext->pstart_lo) | + (u64)le32_to_cpu(ext->pstart_hi) << 32; + if (recsz > offsetof(struct z_erofs_extent, lstart_hi)) + la |= (u64)le32_to_cpu(ext->lstart_hi) << 32; + + if (la > map->m_la) { + r = mid; + if (la > lend) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + lend = la; + } else { + l = mid + 1; + if (map->m_la == la) + r = min(l + 1, r); + lstart = la; + map->m_plen = le32_to_cpu(ext->plen); + map->m_pa = pa; + } + } + last = (l >= vi->z_extents); + } + + if (lstart < lend) { + map->m_la = lstart; + if (last && (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) { + map->m_flags = EROFS_MAP_FRAGMENT; + vi->z_fragmentoff = map->m_plen; + if (recsz > offsetof(struct z_erofs_extent, pstart_lo)) + vi->z_fragmentoff |= map->m_pa << 32; + } else if (map->m_plen & Z_EROFS_EXTENT_PLEN_MASK) { + map->m_flags |= EROFS_MAP_MAPPED | + EROFS_MAP_FULL_MAPPED | EROFS_MAP_ENCODED; + fmt = map->m_plen >> Z_EROFS_EXTENT_PLEN_FMT_BIT; + if (fmt) + map->m_algorithmformat = fmt - 1; + else if (interlaced && !erofs_blkoff(sb, map->m_pa)) + map->m_algorithmformat = + Z_EROFS_COMPRESSION_INTERLACED; + else + map->m_algorithmformat = + Z_EROFS_COMPRESSION_SHIFTED; + if (map->m_plen & Z_EROFS_EXTENT_PLEN_PARTIAL) + map->m_flags |= EROFS_MAP_PARTIAL_REF; + map->m_plen &= Z_EROFS_EXTENT_PLEN_MASK; + } + } + map->m_llen = lend - map->m_la; + return 0; +} + +static int z_erofs_fill_inode(struct inode *inode, struct erofs_map_blocks *map) +{ + struct erofs_inode *const vi = EROFS_I(inode); + struct super_block *const sb = inode->i_sb; + struct z_erofs_map_header *h; + erofs_off_t pos; + int err = 0; + + 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; + + 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); + h = erofs_read_metabuf(&map->buf, sb, pos, erofs_inode_in_metabox(inode)); + if (IS_ERR(h)) { + err = PTR_ERR(h); + goto out_unlock; + } + + /* + * 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_lclusterbits = sb->s_blocksize_bits + (h->h_clusterbits & 15); + if (vi->datalayout == EROFS_INODE_COMPRESSED_FULL && + (vi->z_advise & Z_EROFS_ADVISE_EXTENTS)) { + vi->z_extents = le32_to_cpu(h->h_extents_lo) | + ((u64)le16_to_cpu(h->h_extents_hi) << 32); + goto done; + } + + vi->z_algorithmtype[0] = h->h_algorithmtype & 15; + vi->z_algorithmtype[1] = h->h_algorithmtype >> 4; + if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) + vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff); + else if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) + vi->z_idata_size = le16_to_cpu(h->h_idata_size); + + 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_unlock; + } + if (vi->datalayout == EROFS_INODE_COMPRESSED_COMPACT && + !(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_unlock; + } + + if (vi->z_idata_size || + (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) { + struct erofs_map_blocks tm = { + .buf = __EROFS_BUF_INITIALIZER + }; + + err = z_erofs_map_blocks_fo(inode, &tm, + EROFS_GET_BLOCKS_FINDTAIL); + erofs_put_metabuf(&tm.buf); + if (err < 0) + goto out_unlock; + } +done: + /* paired with smp_mb() at the beginning of the function */ + smp_mb(); + set_bit(EROFS_I_Z_INITED_BIT, &vi->flags); +out_unlock: + clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags); + return err; +} + +static int z_erofs_map_sanity_check(struct inode *inode, + struct erofs_map_blocks *map) +{ + struct erofs_sb_info *sbi = EROFS_I_SB(inode); + u64 pend; + + if (!(map->m_flags & EROFS_MAP_ENCODED)) + return 0; + if (unlikely(map->m_algorithmformat >= Z_EROFS_COMPRESSION_RUNTIME_MAX)) { + erofs_err(inode->i_sb, "unknown algorithm %d @ pos %llu for nid %llu, please upgrade kernel", + map->m_algorithmformat, map->m_la, EROFS_I(inode)->nid); + return -EOPNOTSUPP; + } + if (unlikely(map->m_algorithmformat < Z_EROFS_COMPRESSION_MAX && + !(sbi->available_compr_algs & (1 << map->m_algorithmformat)))) { + erofs_err(inode->i_sb, "inconsistent algorithmtype %u for nid %llu", + map->m_algorithmformat, EROFS_I(inode)->nid); + return -EFSCORRUPTED; + } + if (unlikely(map->m_plen > Z_EROFS_PCLUSTER_MAX_SIZE || + map->m_llen > Z_EROFS_PCLUSTER_MAX_DSIZE)) + return -EOPNOTSUPP; + /* Filesystems beyond 48-bit physical block addresses are invalid */ + if (unlikely(check_add_overflow(map->m_pa, map->m_plen, &pend) || + (pend >> sbi->blkszbits) >= BIT_ULL(48))) + return -EFSCORRUPTED; + return 0; +} + +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_erofs_map_blocks_enter(inode, map, flags); + if (map->m_la >= inode->i_size) { /* post-EOF unmapped extent */ + map->m_llen = map->m_la + 1 - inode->i_size; + map->m_la = inode->i_size; + map->m_flags = 0; + } else { + err = z_erofs_fill_inode(inode, map); + if (!err) { + if (vi->datalayout == EROFS_INODE_COMPRESSED_FULL && + (vi->z_advise & Z_EROFS_ADVISE_EXTENTS)) + err = z_erofs_map_blocks_ext(inode, map, flags); + else + err = z_erofs_map_blocks_fo(inode, map, flags); + } + if (!err) + err = z_erofs_map_sanity_check(inode, map); + if (err) + map->m_llen = 0; + } + trace_erofs_map_blocks_exit(inode, map, flags, err); + 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, +}; |