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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/erofs/erofs_fs.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/erofs/erofs_fs.h')
-rw-r--r--fs/erofs/erofs_fs.h452
1 files changed, 452 insertions, 0 deletions
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
new file mode 100644
index 000000000..dbcd24371
--- /dev/null
+++ b/fs/erofs/erofs_fs.h
@@ -0,0 +1,452 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR Apache-2.0 */
+/*
+ * EROFS (Enhanced ROM File System) on-disk format definition
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * https://www.huawei.com/
+ * Copyright (C) 2021, Alibaba Cloud
+ */
+#ifndef __EROFS_FS_H
+#define __EROFS_FS_H
+
+#define EROFS_SUPER_OFFSET 1024
+
+#define EROFS_FEATURE_COMPAT_SB_CHKSUM 0x00000001
+#define EROFS_FEATURE_COMPAT_MTIME 0x00000002
+
+/*
+ * Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should
+ * be incompatible with this kernel version.
+ */
+#define EROFS_FEATURE_INCOMPAT_ZERO_PADDING 0x00000001
+#define EROFS_FEATURE_INCOMPAT_COMPR_CFGS 0x00000002
+#define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER 0x00000002
+#define EROFS_FEATURE_INCOMPAT_CHUNKED_FILE 0x00000004
+#define EROFS_FEATURE_INCOMPAT_DEVICE_TABLE 0x00000008
+#define EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 0x00000008
+#define EROFS_FEATURE_INCOMPAT_ZTAILPACKING 0x00000010
+#define EROFS_FEATURE_INCOMPAT_FRAGMENTS 0x00000020
+#define EROFS_FEATURE_INCOMPAT_DEDUPE 0x00000020
+#define EROFS_ALL_FEATURE_INCOMPAT \
+ (EROFS_FEATURE_INCOMPAT_ZERO_PADDING | \
+ EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
+ EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER | \
+ EROFS_FEATURE_INCOMPAT_CHUNKED_FILE | \
+ EROFS_FEATURE_INCOMPAT_DEVICE_TABLE | \
+ EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 | \
+ EROFS_FEATURE_INCOMPAT_ZTAILPACKING | \
+ EROFS_FEATURE_INCOMPAT_FRAGMENTS | \
+ EROFS_FEATURE_INCOMPAT_DEDUPE)
+
+#define EROFS_SB_EXTSLOT_SIZE 16
+
+struct erofs_deviceslot {
+ u8 tag[64]; /* digest(sha256), etc. */
+ __le32 blocks; /* total fs blocks of this device */
+ __le32 mapped_blkaddr; /* map starting at mapped_blkaddr */
+ u8 reserved[56];
+};
+#define EROFS_DEVT_SLOT_SIZE sizeof(struct erofs_deviceslot)
+
+/* erofs on-disk super block (currently 128 bytes) */
+struct erofs_super_block {
+ __le32 magic; /* file system magic number */
+ __le32 checksum; /* crc32c(super_block) */
+ __le32 feature_compat;
+ __u8 blkszbits; /* support block_size == PAGE_SIZE only */
+ __u8 sb_extslots; /* superblock size = 128 + sb_extslots * 16 */
+
+ __le16 root_nid; /* nid of root directory */
+ __le64 inos; /* total valid ino # (== f_files - f_favail) */
+
+ __le64 build_time; /* compact inode time derivation */
+ __le32 build_time_nsec; /* compact inode time derivation in ns scale */
+ __le32 blocks; /* used for statfs */
+ __le32 meta_blkaddr; /* start block address of metadata area */
+ __le32 xattr_blkaddr; /* start block address of shared xattr area */
+ __u8 uuid[16]; /* 128-bit uuid for volume */
+ __u8 volume_name[16]; /* volume name */
+ __le32 feature_incompat;
+ union {
+ /* bitmap for available compression algorithms */
+ __le16 available_compr_algs;
+ /* customized sliding window size instead of 64k by default */
+ __le16 lz4_max_distance;
+ } __packed u1;
+ __le16 extra_devices; /* # of devices besides the primary device */
+ __le16 devt_slotoff; /* startoff = devt_slotoff * devt_slotsize */
+ __u8 reserved[6];
+ __le64 packed_nid; /* nid of the special packed inode */
+ __u8 reserved2[24];
+};
+
+/*
+ * erofs inode datalayout (i_format in on-disk inode):
+ * 0 - uncompressed flat inode without tail-packing inline data:
+ * inode, [xattrs], ... | ... | no-holed data
+ * 1 - compressed inode with non-compact indexes:
+ * inode, [xattrs], [map_header], extents ... | ...
+ * 2 - uncompressed flat inode with tail-packing inline data:
+ * inode, [xattrs], tailpacking data, ... | ... | no-holed data
+ * 3 - compressed inode with compact indexes:
+ * inode, [xattrs], map_header, extents ... | ...
+ * 4 - chunk-based inode with (optional) multi-device support:
+ * inode, [xattrs], chunk indexes ... | ...
+ * 5~7 - reserved
+ */
+enum {
+ EROFS_INODE_FLAT_PLAIN = 0,
+ EROFS_INODE_FLAT_COMPRESSION_LEGACY = 1,
+ EROFS_INODE_FLAT_INLINE = 2,
+ EROFS_INODE_FLAT_COMPRESSION = 3,
+ EROFS_INODE_CHUNK_BASED = 4,
+ EROFS_INODE_DATALAYOUT_MAX
+};
+
+static inline bool erofs_inode_is_data_compressed(unsigned int datamode)
+{
+ return datamode == EROFS_INODE_FLAT_COMPRESSION ||
+ datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY;
+}
+
+/* bit definitions of inode i_format */
+#define EROFS_I_VERSION_BITS 1
+#define EROFS_I_DATALAYOUT_BITS 3
+
+#define EROFS_I_VERSION_BIT 0
+#define EROFS_I_DATALAYOUT_BIT 1
+
+#define EROFS_I_ALL \
+ ((1 << (EROFS_I_DATALAYOUT_BIT + EROFS_I_DATALAYOUT_BITS)) - 1)
+
+/* indicate chunk blkbits, thus 'chunksize = blocksize << chunk blkbits' */
+#define EROFS_CHUNK_FORMAT_BLKBITS_MASK 0x001F
+/* with chunk indexes or just a 4-byte blkaddr array */
+#define EROFS_CHUNK_FORMAT_INDEXES 0x0020
+
+#define EROFS_CHUNK_FORMAT_ALL \
+ (EROFS_CHUNK_FORMAT_BLKBITS_MASK | EROFS_CHUNK_FORMAT_INDEXES)
+
+struct erofs_inode_chunk_info {
+ __le16 format; /* chunk blkbits, etc. */
+ __le16 reserved;
+};
+
+/* 32-byte reduced form of an ondisk inode */
+struct erofs_inode_compact {
+ __le16 i_format; /* inode format hints */
+
+/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
+ __le16 i_xattr_icount;
+ __le16 i_mode;
+ __le16 i_nlink;
+ __le32 i_size;
+ __le32 i_reserved;
+ union {
+ /* total compressed blocks for compressed inodes */
+ __le32 compressed_blocks;
+ /* block address for uncompressed flat inodes */
+ __le32 raw_blkaddr;
+
+ /* for device files, used to indicate old/new device # */
+ __le32 rdev;
+
+ /* for chunk-based files, it contains the summary info */
+ struct erofs_inode_chunk_info c;
+ } i_u;
+ __le32 i_ino; /* only used for 32-bit stat compatibility */
+ __le16 i_uid;
+ __le16 i_gid;
+ __le32 i_reserved2;
+};
+
+/* 32-byte on-disk inode */
+#define EROFS_INODE_LAYOUT_COMPACT 0
+/* 64-byte on-disk inode */
+#define EROFS_INODE_LAYOUT_EXTENDED 1
+
+/* 64-byte complete form of an ondisk inode */
+struct erofs_inode_extended {
+ __le16 i_format; /* inode format hints */
+
+/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
+ __le16 i_xattr_icount;
+ __le16 i_mode;
+ __le16 i_reserved;
+ __le64 i_size;
+ union {
+ /* total compressed blocks for compressed inodes */
+ __le32 compressed_blocks;
+ /* block address for uncompressed flat inodes */
+ __le32 raw_blkaddr;
+
+ /* for device files, used to indicate old/new device # */
+ __le32 rdev;
+
+ /* for chunk-based files, it contains the summary info */
+ struct erofs_inode_chunk_info c;
+ } i_u;
+
+ /* only used for 32-bit stat compatibility */
+ __le32 i_ino;
+
+ __le32 i_uid;
+ __le32 i_gid;
+ __le64 i_mtime;
+ __le32 i_mtime_nsec;
+ __le32 i_nlink;
+ __u8 i_reserved2[16];
+};
+
+#define EROFS_MAX_SHARED_XATTRS (128)
+/* h_shared_count between 129 ... 255 are special # */
+#define EROFS_SHARED_XATTR_EXTENT (255)
+
+/*
+ * inline xattrs (n == i_xattr_icount):
+ * erofs_xattr_ibody_header(1) + (n - 1) * 4 bytes
+ * 12 bytes / \
+ * / \
+ * /-----------------------\
+ * | erofs_xattr_entries+ |
+ * +-----------------------+
+ * inline xattrs must starts in erofs_xattr_ibody_header,
+ * for read-only fs, no need to introduce h_refcount
+ */
+struct erofs_xattr_ibody_header {
+ __le32 h_reserved;
+ __u8 h_shared_count;
+ __u8 h_reserved2[7];
+ __le32 h_shared_xattrs[]; /* shared xattr id array */
+};
+
+/* Name indexes */
+#define EROFS_XATTR_INDEX_USER 1
+#define EROFS_XATTR_INDEX_POSIX_ACL_ACCESS 2
+#define EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT 3
+#define EROFS_XATTR_INDEX_TRUSTED 4
+#define EROFS_XATTR_INDEX_LUSTRE 5
+#define EROFS_XATTR_INDEX_SECURITY 6
+
+/* xattr entry (for both inline & shared xattrs) */
+struct erofs_xattr_entry {
+ __u8 e_name_len; /* length of name */
+ __u8 e_name_index; /* attribute name index */
+ __le16 e_value_size; /* size of attribute value */
+ /* followed by e_name and e_value */
+ char e_name[]; /* attribute name */
+};
+
+static inline unsigned int erofs_xattr_ibody_size(__le16 i_xattr_icount)
+{
+ if (!i_xattr_icount)
+ return 0;
+
+ return sizeof(struct erofs_xattr_ibody_header) +
+ sizeof(__u32) * (le16_to_cpu(i_xattr_icount) - 1);
+}
+
+#define EROFS_XATTR_ALIGN(size) round_up(size, sizeof(struct erofs_xattr_entry))
+
+static inline unsigned int erofs_xattr_entry_size(struct erofs_xattr_entry *e)
+{
+ return EROFS_XATTR_ALIGN(sizeof(struct erofs_xattr_entry) +
+ e->e_name_len + le16_to_cpu(e->e_value_size));
+}
+
+/* represent a zeroed chunk (hole) */
+#define EROFS_NULL_ADDR -1
+
+/* 4-byte block address array */
+#define EROFS_BLOCK_MAP_ENTRY_SIZE sizeof(__le32)
+
+/* 8-byte inode chunk indexes */
+struct erofs_inode_chunk_index {
+ __le16 advise; /* always 0, don't care for now */
+ __le16 device_id; /* back-end storage id (with bits masked) */
+ __le32 blkaddr; /* start block address of this inode chunk */
+};
+
+/* maximum supported size of a physical compression cluster */
+#define Z_EROFS_PCLUSTER_MAX_SIZE (1024 * 1024)
+
+/* available compression algorithm types (for h_algorithmtype) */
+enum {
+ Z_EROFS_COMPRESSION_LZ4 = 0,
+ Z_EROFS_COMPRESSION_LZMA = 1,
+ Z_EROFS_COMPRESSION_MAX
+};
+#define Z_EROFS_ALL_COMPR_ALGS ((1 << Z_EROFS_COMPRESSION_MAX) - 1)
+
+/* 14 bytes (+ length field = 16 bytes) */
+struct z_erofs_lz4_cfgs {
+ __le16 max_distance;
+ __le16 max_pclusterblks;
+ u8 reserved[10];
+} __packed;
+
+/* 14 bytes (+ length field = 16 bytes) */
+struct z_erofs_lzma_cfgs {
+ __le32 dict_size;
+ __le16 format;
+ u8 reserved[8];
+} __packed;
+
+#define Z_EROFS_LZMA_MAX_DICT_SIZE (8 * Z_EROFS_PCLUSTER_MAX_SIZE)
+
+/*
+ * bit 0 : COMPACTED_2B indexes (0 - off; 1 - on)
+ * e.g. for 4k logical cluster size, 4B if compacted 2B is off;
+ * (4B) + 2B + (4B) if compacted 2B is on.
+ * bit 1 : HEAD1 big pcluster (0 - off; 1 - on)
+ * bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
+ * bit 3 : tailpacking inline pcluster (0 - off; 1 - on)
+ * bit 4 : interlaced plain pcluster (0 - off; 1 - on)
+ * bit 5 : fragment pcluster (0 - off; 1 - on)
+ */
+#define Z_EROFS_ADVISE_COMPACTED_2B 0x0001
+#define Z_EROFS_ADVISE_BIG_PCLUSTER_1 0x0002
+#define Z_EROFS_ADVISE_BIG_PCLUSTER_2 0x0004
+#define Z_EROFS_ADVISE_INLINE_PCLUSTER 0x0008
+#define Z_EROFS_ADVISE_INTERLACED_PCLUSTER 0x0010
+#define Z_EROFS_ADVISE_FRAGMENT_PCLUSTER 0x0020
+
+#define Z_EROFS_FRAGMENT_INODE_BIT 7
+struct z_erofs_map_header {
+ union {
+ /* fragment data offset in the packed inode */
+ __le32 h_fragmentoff;
+ struct {
+ __le16 h_reserved1;
+ /* indicates the encoded size of tailpacking data */
+ __le16 h_idata_size;
+ };
+ };
+ __le16 h_advise;
+ /*
+ * bit 0-3 : algorithm type of head 1 (logical cluster type 01);
+ * bit 4-7 : algorithm type of head 2 (logical cluster type 11).
+ */
+ __u8 h_algorithmtype;
+ /*
+ * bit 0-2 : logical cluster bits - 12, e.g. 0 for 4096;
+ * bit 3-6 : reserved;
+ * bit 7 : move the whole file into packed inode or not.
+ */
+ __u8 h_clusterbits;
+};
+
+#define Z_EROFS_VLE_LEGACY_HEADER_PADDING 8
+
+/*
+ * Fixed-sized output compression on-disk logical cluster type:
+ * 0 - literal (uncompressed) lcluster
+ * 1,3 - compressed lcluster (for HEAD lclusters)
+ * 2 - compressed lcluster (for NONHEAD lclusters)
+ *
+ * In detail,
+ * 0 - literal (uncompressed) lcluster,
+ * di_advise = 0
+ * di_clusterofs = the literal data offset of the lcluster
+ * di_blkaddr = the blkaddr of the literal pcluster
+ *
+ * 1,3 - compressed lcluster (for HEAD lclusters)
+ * di_advise = 1 or 3
+ * di_clusterofs = the decompressed data offset of the lcluster
+ * di_blkaddr = the blkaddr of the compressed pcluster
+ *
+ * 2 - compressed lcluster (for NONHEAD lclusters)
+ * di_advise = 2
+ * di_clusterofs =
+ * the decompressed data offset in its own HEAD lcluster
+ * di_u.delta[0] = distance to this HEAD lcluster
+ * di_u.delta[1] = distance to the next HEAD lcluster
+ */
+enum {
+ Z_EROFS_VLE_CLUSTER_TYPE_PLAIN = 0,
+ Z_EROFS_VLE_CLUSTER_TYPE_HEAD1 = 1,
+ Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD = 2,
+ Z_EROFS_VLE_CLUSTER_TYPE_HEAD2 = 3,
+ Z_EROFS_VLE_CLUSTER_TYPE_MAX
+};
+
+#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS 2
+#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT 0
+
+/* (noncompact only, HEAD) This pcluster refers to partial decompressed data */
+#define Z_EROFS_VLE_DI_PARTIAL_REF (1 << 15)
+
+/*
+ * D0_CBLKCNT will be marked _only_ at the 1st non-head lcluster to store the
+ * compressed block count of a compressed extent (in logical clusters, aka.
+ * block count of a pcluster).
+ */
+#define Z_EROFS_VLE_DI_D0_CBLKCNT (1 << 11)
+
+struct z_erofs_vle_decompressed_index {
+ __le16 di_advise;
+ /* where to decompress in the head lcluster */
+ __le16 di_clusterofs;
+
+ union {
+ /* for the HEAD lclusters */
+ __le32 blkaddr;
+ /*
+ * for the NONHEAD lclusters
+ * [0] - distance to its HEAD lcluster
+ * [1] - distance to the next HEAD lcluster
+ */
+ __le16 delta[2];
+ } di_u;
+};
+
+#define Z_EROFS_VLE_LEGACY_INDEX_ALIGN(size) \
+ (round_up(size, sizeof(struct z_erofs_vle_decompressed_index)) + \
+ sizeof(struct z_erofs_map_header) + Z_EROFS_VLE_LEGACY_HEADER_PADDING)
+
+/* dirent sorts in alphabet order, thus we can do binary search */
+struct erofs_dirent {
+ __le64 nid; /* node number */
+ __le16 nameoff; /* start offset of file name */
+ __u8 file_type; /* file type */
+ __u8 reserved; /* reserved */
+} __packed;
+
+/*
+ * EROFS file types should match generic FT_* types and
+ * it seems no need to add BUILD_BUG_ONs since potential
+ * unmatchness will break other fses as well...
+ */
+
+#define EROFS_NAME_LEN 255
+
+/* check the EROFS on-disk layout strictly at compile time */
+static inline void erofs_check_ondisk_layout_definitions(void)
+{
+ const __le64 fmh = *(__le64 *)&(struct z_erofs_map_header) {
+ .h_clusterbits = 1 << Z_EROFS_FRAGMENT_INODE_BIT
+ };
+
+ BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
+ BUILD_BUG_ON(sizeof(struct erofs_inode_compact) != 32);
+ BUILD_BUG_ON(sizeof(struct erofs_inode_extended) != 64);
+ BUILD_BUG_ON(sizeof(struct erofs_xattr_ibody_header) != 12);
+ BUILD_BUG_ON(sizeof(struct erofs_xattr_entry) != 4);
+ BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_info) != 4);
+ BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) != 8);
+ BUILD_BUG_ON(sizeof(struct z_erofs_map_header) != 8);
+ BUILD_BUG_ON(sizeof(struct z_erofs_vle_decompressed_index) != 8);
+ BUILD_BUG_ON(sizeof(struct erofs_dirent) != 12);
+ /* keep in sync between 2 index structures for better extendibility */
+ BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) !=
+ sizeof(struct z_erofs_vle_decompressed_index));
+ BUILD_BUG_ON(sizeof(struct erofs_deviceslot) != 128);
+
+ BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) <
+ Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1);
+ /* exclude old compiler versions like gcc 7.5.0 */
+ BUILD_BUG_ON(__builtin_constant_p(fmh) ?
+ fmh != cpu_to_le64(1ULL << 63) : 0);
+}
+
+#endif