:: commit 81faf039af20592d150da4a1293222f94bf9e4c0
Add ext4 extent support
diff --git a/stage2/fs/ext2.c b/stage2/fs/ext2.c
index a087ee33..1a8b49cc 100644
--- a/stage2/fs/ext2.c
+++ b/stage2/fs/ext2.c
@@ -16,6 +16,9 @@
#define EXT2_IF_INLINE_DATA 0x8000
#define EXT2_IF_ENCRYPT 0x10000
+/* Ext4 flags */
+#define EXT4_EXTENTS_FLAG 0x80000
+
#define EXT2_S_MAGIC 0xEF53
/* Superblock Fields */
@@ -90,6 +93,28 @@ struct ext2_dir_entry {
uint8_t type;
} __attribute__((packed));
+struct ext4_extent_header {
+ uint16_t magic;
+ uint16_t entries;
+ uint16_t max;
+ uint16_t depth;
+ uint16_t generation;
+} __attribute__((packed));
+
+struct ext4_extent {
+ uint32_t block;
+ uint16_t len;
+ uint16_t start_hi;
+ uint32_t start;
+} __attribute__((packed));
+
+struct ext4_extent_idx {
+ uint32_t block;
+ uint32_t leaf;
+ uint16_t leaf_hi;
+ uint16_t empty;
+} __attribute__((packed));
+
static int inode_read(void *buf, uint64_t loc, uint64_t count,
uint64_t block_size, struct ext2_inode *inode,
uint64_t drive, struct part *part);
@@ -212,6 +237,38 @@ int ext2_read(struct ext2_file_handle *file, void *buf, uint64_t loc, uint64_t c
file->drive, &file->part);
}
+static struct ext4_extent_header* ext4_find_leaf(struct ext4_extent_header* ext_block, uint32_t read_block, uint64_t block_size, uint64_t drive, struct part *part) {
+ struct ext4_extent_idx* index;
+ void* buf = NULL;
+
+ while (1) {
+ index = (struct ext4_extent_idx*)((size_t)ext_block + 12);
+
+ #define EXT4_EXT_MAGIC 0xf30a
+ if (ext_block->magic != EXT4_EXT_MAGIC)
+ panic("invalid extent magic");
+
+ if (ext_block->depth == 0) {
+ return ext_block;
+ }
+
+ int i;
+ for (i = 0; i < ext_block->entries; i++) {
+ if(read_block < index[i].block)
+ break;
+ }
+
+ if (--i < 0)
+ panic("extent not found");
+
+ uint64_t block = (index[i].leaf_hi << 32) | index[i].leaf;
+ if(!buf)
+ buf = balloc(block_size);
+ read_partition(drive, part, buf, (block * block_size), block_size);
+ ext_block = buf;
+ }
+}
+
static int inode_read(void *buf, uint64_t loc, uint64_t count,
uint64_t block_size, struct ext2_inode *inode,
uint64_t drive, struct part *part) {
@@ -225,7 +282,35 @@ static int inode_read(void *buf, uint64_t loc, uint64_t count,
uint32_t block_index;
- if (block < 12) {
+ if (inode->i_flags & EXT4_EXTENTS_FLAG) {
+ struct ext4_extent_header *leaf;
+ struct ext4_extent *ext;
+ int i;
+
+ leaf = ext4_find_leaf((struct ext4_extent_header*)inode->i_blocks, block, block_size, drive, part);
+
+ if (!leaf)
+ panic("invalid extent");
+ ext = (struct ext4_extent*)((size_t)leaf + 12);
+
+ for (i = 0; i < leaf->entries; i++) {
+ if (block < ext[i].block) {
+ break;
+ }
+ }
+
+ if (--i >= 0) {
+ block -= ext[i].block;
+ if (block >= ext[i].len) {
+ panic("block longer than extent");
+ } else {
+ uint64_t start = (ext[i].start_hi << 32) + ext[i].start;
+ block_index = start + block;
+ }
+ } else {
+ panic("extent for block not found");
+ }
+ } else if (block < 12) {
// Direct block
block_index = inode->i_blocks[block];
} else {
@@ -286,11 +371,9 @@ int ext2_check_signature(int drive, int partition) {
return 1;
if (sb.s_feature_incompat & EXT2_IF_COMPRESSION ||
- sb.s_feature_incompat & EXT2_IF_EXTENTS ||
sb.s_feature_incompat & EXT2_IF_INLINE_DATA ||
- sb.s_feature_incompat & EXT2_IF_64BIT ||
sb.s_feature_incompat & EXT2_IF_ENCRYPT)
- panic("EXT2: filesystem has unsupported features");
+ panic("EXT2: filesystem has unsupported features %x", sb.s_feature_incompat);
return 1;
}
