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-rw-r--r--fs/erofs/decompressor.c2
-rw-r--r--fs/erofs/erofs_fs.h16
-rw-r--r--fs/erofs/internal.h5
-rw-r--r--fs/erofs/super.c141
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);
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-02-13 20:12:50 +0000