diff options
| -rw-r--r-- | fs/erofs/decompressor.c | 2 | ||||
| -rw-r--r-- | fs/erofs/erofs_fs.h | 16 | ||||
| -rw-r--r-- | fs/erofs/internal.h | 5 | ||||
| -rw-r--r-- | fs/erofs/super.c | 141 |
4 files changed, 157 insertions, 7 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 97538ff24a19..27aa6a99b371 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -41,7 +41,7 @@ int z_erofs_load_lz4_config(struct super_block *sb, } distance = le16_to_cpu(lz4->max_distance); } else { - distance = le16_to_cpu(dsb->lz4_max_distance); + distance = le16_to_cpu(dsb->u1.lz4_max_distance); } EROFS_SB(sb)->lz4.max_distance_pages = distance ? diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h index 700597e9c810..17bc0b5f117d 100644 --- a/fs/erofs/erofs_fs.h +++ b/fs/erofs/erofs_fs.h @@ -18,15 +18,18 @@ * be incompatible with this kernel version. */ #define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING 0x00000001 +#define EROFS_FEATURE_INCOMPAT_COMPR_CFGS 0x00000002 #define EROFS_ALL_FEATURE_INCOMPAT EROFS_FEATURE_INCOMPAT_LZ4_0PADDING -/* 128-byte erofs on-disk super block */ +#define EROFS_SB_EXTSLOT_SIZE 16 + +/* 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 reserved; + __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) */ @@ -39,8 +42,12 @@ struct erofs_super_block { __u8 uuid[16]; /* 128-bit uuid for volume */ __u8 volume_name[16]; /* volume name */ __le32 feature_incompat; - /* customized lz4 sliding window size instead of 64k by default */ - __le16 lz4_max_distance; + 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; __u8 reserved2[42]; }; @@ -199,6 +206,7 @@ enum { Z_EROFS_COMPRESSION_LZ4 = 0, 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 { diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index b02fc64fcece..60063bbbb91a 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -75,6 +75,7 @@ struct erofs_sb_info { struct xarray managed_pslots; unsigned int shrinker_run_no; + u16 available_compr_algs; /* pseudo inode to manage cached pages */ struct inode *managed_cache; @@ -90,6 +91,7 @@ struct erofs_sb_info { /* inode slot unit size in bit shift */ unsigned char islotbits; + u32 sb_size; /* total superblock size */ u32 build_time_nsec; u64 build_time; @@ -233,6 +235,7 @@ static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \ } EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING) +EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS) EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM) /* atomic flag definitions */ @@ -452,7 +455,7 @@ static inline int z_erofs_load_lz4_config(struct super_block *sb, struct erofs_super_block *dsb, struct z_erofs_lz4_cfgs *lz4, int len) { - if (lz4 || dsb->lz4_max_distance) { + if (lz4 || dsb->u1.lz4_max_distance) { erofs_err(sb, "lz4 algorithm isn't enabled"); return -EINVAL; } diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 1ca8da3f2125..b641658e772f 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -122,6 +122,136 @@ static bool check_layout_compatibility(struct super_block *sb, return true; } +#ifdef CONFIG_EROFS_FS_ZIP +/* read variable-sized metadata, offset will be aligned by 4-byte */ +static void *erofs_read_metadata(struct super_block *sb, struct page **pagep, + erofs_off_t *offset, int *lengthp) +{ + struct page *page = *pagep; + u8 *buffer, *ptr; + int len, i, cnt; + erofs_blk_t blk; + + *offset = round_up(*offset, 4); + blk = erofs_blknr(*offset); + + if (!page || page->index != blk) { + if (page) { + unlock_page(page); + put_page(page); + } + page = erofs_get_meta_page(sb, blk); + if (IS_ERR(page)) + goto err_nullpage; + } + + ptr = kmap(page); + len = le16_to_cpu(*(__le16 *)&ptr[erofs_blkoff(*offset)]); + if (!len) + len = U16_MAX + 1; + buffer = kmalloc(len, GFP_KERNEL); + if (!buffer) { + buffer = ERR_PTR(-ENOMEM); + goto out; + } + *offset += sizeof(__le16); + *lengthp = len; + + for (i = 0; i < len; i += cnt) { + cnt = min(EROFS_BLKSIZ - (int)erofs_blkoff(*offset), len - i); + blk = erofs_blknr(*offset); + + if (!page || page->index != blk) { + if (page) { + kunmap(page); + unlock_page(page); + put_page(page); + } + page = erofs_get_meta_page(sb, blk); + if (IS_ERR(page)) { + kfree(buffer); + goto err_nullpage; + } + ptr = kmap(page); + } + memcpy(buffer + i, ptr + erofs_blkoff(*offset), cnt); + *offset += cnt; + } +out: + kunmap(page); + *pagep = page; + return buffer; +err_nullpage: + *pagep = NULL; + return page; +} + +static int erofs_load_compr_cfgs(struct super_block *sb, + struct erofs_super_block *dsb) +{ + struct erofs_sb_info *sbi; + struct page *page; + unsigned int algs, alg; + erofs_off_t offset; + int size, ret; + + sbi = EROFS_SB(sb); + sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs); + + if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) { + erofs_err(sb, "try to load compressed fs with unsupported algorithms %x", + sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS); + return -EINVAL; + } + + offset = EROFS_SUPER_OFFSET + sbi->sb_size; + page = NULL; + alg = 0; + ret = 0; + + for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) { + void *data; + + if (!(algs & 1)) + continue; + + data = erofs_read_metadata(sb, &page, &offset, &size); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + goto err; + } + + switch (alg) { + case Z_EROFS_COMPRESSION_LZ4: + ret = z_erofs_load_lz4_config(sb, dsb, data, size); + break; + default: + DBG_BUGON(1); + ret = -EFAULT; + } + kfree(data); + if (ret) + goto err; + } +err: + if (page) { + unlock_page(page); + put_page(page); + } + return ret; +} +#else +static int erofs_load_compr_cfgs(struct super_block *sb, + struct erofs_super_block *dsb) +{ + if (dsb->u1.available_compr_algs) { + erofs_err(sb, "try to load compressed fs when compression is disabled"); + return -EINVAL; + } + return 0; +} +#endif + static int erofs_read_superblock(struct super_block *sb) { struct erofs_sb_info *sbi; @@ -166,6 +296,12 @@ static int erofs_read_superblock(struct super_block *sb) if (!check_layout_compatibility(sb, dsb)) goto out; + sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE; + if (sbi->sb_size > EROFS_BLKSIZ) { + erofs_err(sb, "invalid sb_extslots %u (more than a fs block)", + sbi->sb_size); + goto out; + } sbi->blocks = le32_to_cpu(dsb->blocks); sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr); #ifdef CONFIG_EROFS_FS_XATTR @@ -189,7 +325,10 @@ static int erofs_read_superblock(struct super_block *sb) } /* parse on-disk compression configurations */ - ret = z_erofs_load_lz4_config(sb, dsb, NULL, 0); + if (erofs_sb_has_compr_cfgs(sbi)) + ret = erofs_load_compr_cfgs(sb, dsb); + else + ret = z_erofs_load_lz4_config(sb, dsb, NULL, 0); out: kunmap(page); put_page(page); |