@@ -80,3 +80,12 @@ config EROFS_FS_SECURITY
If you are not using a security module, say N.
+config EROFS_FS_ZIP
+ bool "EROFS Data Compresssion Support"
+ depends on EROFS_FS
+ select LZ4_DECOMPRESS
+ help
+ Enable fixed-sized output compression for EROFS.
+
+ If you don't want to enable compression feature, say N.
+
@@ -7,4 +7,5 @@ ccflags-y += -DEROFS_VERSION=\"$(EROFS_VERSION)\"
obj-$(CONFIG_EROFS_FS) += erofs.o
erofs-objs := super.o inode.o data.o namei.o dir.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += zmap.o
@@ -205,7 +205,7 @@ static int fill_inode(struct inode *inode, int isdir)
}
if (is_inode_layout_compression(inode)) {
- err = -ENOTSUPP;
+ err = z_erofs_fill_inode(inode);
goto out_unlock;
}
@@ -171,9 +171,12 @@ static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
/* atomic flag definitions */
#define EROFS_V_EA_INITED_BIT 0
+#define EROFS_V_Z_INITED_BIT 1
/* bitlock definitions (arranged in reverse order) */
#define EROFS_V_BL_XATTR_BIT (BITS_PER_LONG - 1)
+#define EROFS_V_BL_Z_BIT (BITS_PER_LONG - 2)
+
struct erofs_vnode {
erofs_nid_t nid;
@@ -187,7 +190,17 @@ struct erofs_vnode {
unsigned xattr_shared_count;
unsigned *xattr_shared_xattrs;
- erofs_blk_t raw_blkaddr;
+ union {
+ erofs_blk_t raw_blkaddr;
+#ifdef CONFIG_EROFS_FS_ZIP
+ struct {
+ unsigned short z_advise;
+ unsigned char z_algorithmtype[2];
+ unsigned char z_logical_clusterbits;
+ unsigned char z_physical_clusterbits[2];
+ };
+#endif
+ };
/* the corresponding vfs inode */
struct inode vfs_inode;
};
@@ -260,6 +273,10 @@ enum {
#define EROFS_MAP_MAPPED (1 << BH_Mapped)
/* Located in metadata (could be copied from bd_inode) */
#define EROFS_MAP_META (1 << BH_Meta)
+/* The extent has been compressed */
+#define EROFS_MAP_ZIPPED (1 << BH_Zipped)
+/* The length of extent is full */
+#define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
struct erofs_map_blocks {
erofs_off_t m_pa, m_la;
@@ -273,6 +290,22 @@ struct erofs_map_blocks {
/* Flags used by erofs_map_blocks() */
#define EROFS_GET_BLOCKS_RAW 0x0001
+/* zmap.c */
+#ifdef CONFIG_EROFS_FS_ZIP
+int z_erofs_fill_inode(struct inode *inode);
+int z_erofs_map_blocks_iter(struct inode *inode,
+ struct erofs_map_blocks *map,
+ int flags);
+#else
+static inline int z_erofs_fill_inode(struct inode *inode) { return -ENOTSUPP; }
+static inline int z_erofs_map_blocks_iter(struct inode *inode,
+ struct erofs_map_blocks *map,
+ int flags)
+{
+ return -ENOTSUPP;
+}
+#endif
+
/* data.c */
static inline struct bio *erofs_grab_bio(struct super_block *sb,
erofs_blk_t blkaddr,
new file mode 100644
@@ -0,0 +1,460 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/zmap.c
+ *
+ * Copyright (C) 2018-2019 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ */
+#include "internal.h"
+#include <asm/unaligned.h>
+#include <trace/events/erofs.h>
+
+int z_erofs_fill_inode(struct inode *inode)
+{
+ struct erofs_vnode *const vi = EROFS_V(inode);
+
+ if (vi->datamode == 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;
+ vi->z_physical_clusterbits[0] = vi->z_logical_clusterbits;
+ vi->z_physical_clusterbits[1] = vi->z_logical_clusterbits;
+ set_bit(EROFS_V_Z_INITED_BIT, &vi->flags);
+ }
+ return -ENOTSUPP;
+}
+
+static int fill_inode_lazy(struct inode *inode)
+{
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ struct super_block *const sb = inode->i_sb;
+ int err;
+ erofs_off_t pos;
+ struct page *page;
+ void *kaddr;
+ struct z_erofs_map_header *h;
+
+ if (test_bit(EROFS_V_Z_INITED_BIT, &vi->flags))
+ return 0;
+
+ if (wait_on_bit_lock(&vi->flags, EROFS_V_BL_Z_BIT, TASK_KILLABLE))
+ return -ERESTARTSYS;
+
+ err = 0;
+ if (test_bit(EROFS_V_Z_INITED_BIT, &vi->flags))
+ goto out_unlock;
+
+ DBG_BUGON(vi->datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
+
+ pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
+ vi->xattr_isize, 8);
+ page = erofs_get_meta_page(sb, erofs_blknr(pos), false);
+ if (IS_ERR(page)) {
+ err = PTR_ERR(page);
+ goto out_unlock;
+ }
+
+ kaddr = kmap_atomic(page);
+
+ h = kaddr + erofs_blkoff(pos);
+ 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;
+
+ if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX) {
+ errln("unknown compression format %u for nid %llu, please upgrade kernel",
+ vi->z_algorithmtype[0], vi->nid);
+ err = -ENOTSUPP;
+ goto unmap_done;
+ }
+
+ vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
+ vi->z_physical_clusterbits[0] = vi->z_logical_clusterbits +
+ ((h->h_clusterbits >> 3) & 3);
+
+ if (vi->z_physical_clusterbits[0] != LOG_BLOCK_SIZE) {
+ errln("unsupported physical clusterbits %u for nid %llu, please upgrade kernel",
+ vi->z_physical_clusterbits[0], vi->nid);
+ err = -ENOTSUPP;
+ goto unmap_done;
+ }
+
+ vi->z_physical_clusterbits[1] = vi->z_logical_clusterbits +
+ ((h->h_clusterbits >> 5) & 7);
+unmap_done:
+ kunmap_atomic(kaddr);
+ unlock_page(page);
+ put_page(page);
+
+ set_bit(EROFS_V_Z_INITED_BIT, &vi->flags);
+out_unlock:
+ clear_and_wake_up_bit(EROFS_V_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;
+ u16 clusterofs;
+ u16 delta[2];
+ erofs_blk_t pblk;
+};
+
+static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m,
+ erofs_blk_t eblk)
+{
+ struct super_block *const sb = m->inode->i_sb;
+ struct erofs_map_blocks *const map = m->map;
+ struct page *mpage = map->mpage;
+
+ if (mpage) {
+ if (mpage->index == eblk) {
+ if (!m->kaddr)
+ m->kaddr = kmap_atomic(mpage);
+ return 0;
+ }
+
+ if (m->kaddr) {
+ kunmap_atomic(m->kaddr);
+ m->kaddr = NULL;
+ }
+ put_page(mpage);
+ }
+
+ mpage = erofs_get_meta_page(sb, eblk, false);
+ if (IS_ERR(mpage)) {
+ map->mpage = NULL;
+ return PTR_ERR(mpage);
+ }
+ m->kaddr = kmap_atomic(mpage);
+ unlock_page(mpage);
+ map->mpage = mpage;
+ return 0;
+}
+
+static int vle_legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
+ unsigned long lcn)
+{
+ struct inode *const inode = m->inode;
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ const erofs_off_t ibase = iloc(EROFS_I_SB(inode), vi->nid);
+ const erofs_off_t pos =
+ Z_EROFS_VLE_LEGACY_INDEX_ALIGN(ibase + 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;
+ int err;
+
+ err = z_erofs_reload_indexes(m, erofs_blknr(pos));
+ if (err)
+ return err;
+
+ 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]);
+ 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_HEAD:
+ m->clusterofs = le16_to_cpu(di->di_clusterofs);
+ m->pblk = le32_to_cpu(di->di_u.blkaddr);
+ break;
+ default:
+ DBG_BUGON(1);
+ return -EIO;
+ }
+ 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 unpack_compacted_index(struct z_erofs_maprecorder *m,
+ unsigned int amortizedshift,
+ unsigned int eofs)
+{
+ struct erofs_vnode *const vi = EROFS_V(m->inode);
+ const unsigned int lclusterbits = vi->z_logical_clusterbits;
+ const unsigned int lomask = (1 << lclusterbits) - 1;
+ unsigned int vcnt, base, lo, encodebits, nblk;
+ int i;
+ u8 *in, type;
+
+ if (1 << amortizedshift == 4)
+ vcnt = 2;
+ else if (1 << amortizedshift == 2 && lclusterbits == 12)
+ vcnt = 16;
+ else
+ return -ENOTSUPP;
+
+ encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
+ 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;
+ if (i + 1 != 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;
+ m->delta[0] = lo + 1;
+ return 0;
+ }
+ m->clusterofs = lo;
+ m->delta[0] = 0;
+ /* figout out blkaddr (pblk) for HEAD lclusters */
+ 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;
+ }
+ 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)
+{
+ struct inode *const inode = m->inode;
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ const unsigned int lclusterbits = vi->z_logical_clusterbits;
+ const erofs_off_t ebase = ALIGN(iloc(EROFS_I_SB(inode), vi->nid) +
+ vi->inode_isize + vi->xattr_isize, 8) +
+ sizeof(struct z_erofs_map_header);
+ 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;
+ int err;
+
+ if (lclusterbits != 12)
+ return -ENOTSUPP;
+
+ 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_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);
+ err = z_erofs_reload_indexes(m, erofs_blknr(pos));
+ if (err)
+ return err;
+ return unpack_compacted_index(m, amortizedshift, erofs_blkoff(pos));
+}
+
+static int vle_load_cluster_from_disk(struct z_erofs_maprecorder *m,
+ unsigned int lcn)
+{
+ const unsigned int datamode = EROFS_V(m->inode)->datamode;
+
+ if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
+ return vle_legacy_load_cluster_from_disk(m, lcn);
+
+ if (datamode == EROFS_INODE_FLAT_COMPRESSION)
+ return compacted_load_cluster_from_disk(m, lcn);
+
+ return -EINVAL;
+}
+
+static int vle_extent_lookback(struct z_erofs_maprecorder *m,
+ unsigned int lookback_distance)
+{
+ struct erofs_vnode *const vi = EROFS_V(m->inode);
+ struct erofs_map_blocks *const map = m->map;
+ const unsigned int lclusterbits = vi->z_logical_clusterbits;
+ unsigned long lcn = m->lcn;
+ int err;
+
+ if (lcn < lookback_distance) {
+ DBG_BUGON(1);
+ return -EIO;
+ }
+
+ /* load extent head logical cluster if needed */
+ lcn -= lookback_distance;
+ err = vle_load_cluster_from_disk(m, lcn);
+ if (err)
+ return err;
+
+ switch (m->type) {
+ case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+ return vle_extent_lookback(m, m->delta[0]);
+ case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+ map->m_flags &= ~EROFS_MAP_ZIPPED;
+ /* fallthrough */
+ case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+ map->m_la = (lcn << lclusterbits) | m->clusterofs;
+ break;
+ default:
+ errln("unknown type %u at lcn %lu of nid %llu",
+ m->type, lcn, vi->nid);
+ DBG_BUGON(1);
+ return -EIO;
+ }
+ return 0;
+}
+
+int z_erofs_map_blocks_iter(struct inode *inode,
+ struct erofs_map_blocks *map,
+ int flags)
+{
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ struct z_erofs_maprecorder m = {
+ .inode = inode,
+ .map = map,
+ };
+ int err = 0;
+ unsigned int lclusterbits, endoff;
+ unsigned long long ofs, end;
+
+ trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
+
+ /* when trying to read beyond EOF, leave it unmapped */
+ if (unlikely(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 = fill_inode_lazy(inode);
+ if (err)
+ goto out;
+
+ lclusterbits = vi->z_logical_clusterbits;
+ ofs = map->m_la;
+ m.lcn = ofs >> lclusterbits;
+ endoff = ofs & ((1 << lclusterbits) - 1);
+
+ err = vle_load_cluster_from_disk(&m, m.lcn);
+ if (err)
+ goto unmap_out;
+
+ map->m_flags = EROFS_MAP_ZIPPED; /* by default, compressed */
+ end = (m.lcn + 1ULL) << lclusterbits;
+
+ switch (m.type) {
+ case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+ if (endoff >= m.clusterofs)
+ map->m_flags &= ~EROFS_MAP_ZIPPED;
+ /* fallthrough */
+ case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+ if (endoff >= m.clusterofs) {
+ map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
+ break;
+ }
+ /* m.lcn should be >= 1 if endoff < m.clusterofs */
+ if (unlikely(!m.lcn)) {
+ errln("invalid logical cluster 0 at nid %llu",
+ vi->nid);
+ err = -EIO;
+ 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 correspoinding first chunk */
+ err = vle_extent_lookback(&m, m.delta[0]);
+ if (unlikely(err))
+ goto unmap_out;
+ break;
+ default:
+ errln("unknown type %u at offset %llu of nid %llu",
+ m.type, ofs, vi->nid);
+ err = -EIO;
+ goto unmap_out;
+ }
+
+ map->m_llen = end - map->m_la;
+ map->m_plen = 1 << lclusterbits;
+ map->m_pa = blknr_to_addr(m.pblk);
+ map->m_flags |= EROFS_MAP_MAPPED;
+
+unmap_out:
+ if (m.kaddr)
+ kunmap_atomic(m.kaddr);
+
+out:
+ debugln("%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);
+
+ 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;
+}
+
@@ -20,7 +20,8 @@
#define show_mflags(flags) __print_flags(flags, "", \
{ EROFS_MAP_MAPPED, "M" }, \
- { EROFS_MAP_META, "I" })
+ { EROFS_MAP_META, "I" }, \
+ { EROFS_MAP_ZIPPED, "Z" })
TRACE_EVENT(erofs_lookup,
@@ -172,6 +173,13 @@ DEFINE_EVENT(erofs__map_blocks_enter, erofs_map_blocks_flatmode_enter,
TP_ARGS(inode, map, flags)
);
+DEFINE_EVENT(erofs__map_blocks_enter, z_erofs_map_blocks_iter_enter,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned int flags),
+
+ TP_ARGS(inode, map, flags)
+);
+
DECLARE_EVENT_CLASS(erofs__map_blocks_exit,
TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
unsigned int flags, int ret),
@@ -217,6 +225,13 @@ DEFINE_EVENT(erofs__map_blocks_exit, erofs_map_blocks_flatmode_exit,
TP_ARGS(inode, map, flags, ret)
);
+DEFINE_EVENT(erofs__map_blocks_exit, z_erofs_map_blocks_iter_exit,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned int flags, int ret),
+
+ TP_ARGS(inode, map, flags, ret)
+);
+
TRACE_EVENT(erofs_destroy_inode,
TP_PROTO(struct inode *inode),
This patch adds EROFS compression indexes support, including legacy and compacted 2/4B indexes. In addition, it introduces an iterable L2P mapping operation called 'z_erofs_map_blocks_iter'. Compared with 'erofs_map_blocks', it avoids a number of redundant 'release and regrab' processes if they request the same meta page. Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> --- fs/erofs/Kconfig | 9 + fs/erofs/Makefile | 1 + fs/erofs/inode.c | 2 +- fs/erofs/internal.h | 35 ++- fs/erofs/zmap.c | 460 +++++++++++++++++++++++++++++++++++ include/trace/events/erofs.h | 17 +- 6 files changed, 521 insertions(+), 3 deletions(-) create mode 100644 fs/erofs/zmap.c