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-rw-r--r--grub-core/fs/ext2.c991
1 files changed, 991 insertions, 0 deletions
diff --git a/grub-core/fs/ext2.c b/grub-core/fs/ext2.c
new file mode 100644
index 0000000..0fdf151
--- /dev/null
+++ b/grub-core/fs/ext2.c
@@ -0,0 +1,991 @@
+/* ext2.c - Second Extended filesystem */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2003,2004,2005,2007,2008,2009 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* Magic value used to identify an ext2 filesystem. */
+#define EXT2_MAGIC 0xEF53
+/* Amount of indirect blocks in an inode. */
+#define INDIRECT_BLOCKS 12
+/* Maximum length of a pathname. */
+#define EXT2_PATH_MAX 4096
+/* Maximum nesting of symlinks, used to prevent a loop. */
+#define EXT2_MAX_SYMLINKCNT 8
+
+/* The good old revision and the default inode size. */
+#define EXT2_GOOD_OLD_REVISION 0
+#define EXT2_GOOD_OLD_INODE_SIZE 128
+
+/* Filetype used in directory entry. */
+#define FILETYPE_UNKNOWN 0
+#define FILETYPE_REG 1
+#define FILETYPE_DIRECTORY 2
+#define FILETYPE_SYMLINK 7
+
+/* Filetype information as used in inodes. */
+#define FILETYPE_INO_MASK 0170000
+#define FILETYPE_INO_REG 0100000
+#define FILETYPE_INO_DIRECTORY 0040000
+#define FILETYPE_INO_SYMLINK 0120000
+
+#include <grub/err.h>
+#include <grub/file.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/disk.h>
+#include <grub/dl.h>
+#include <grub/types.h>
+#include <grub/fshelp.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+/* Log2 size of ext2 block in 512 blocks. */
+#define LOG2_EXT2_BLOCK_SIZE(data) \
+ (grub_le_to_cpu32 (data->sblock.log2_block_size) + 1)
+
+/* Log2 size of ext2 block in bytes. */
+#define LOG2_BLOCK_SIZE(data) \
+ (grub_le_to_cpu32 (data->sblock.log2_block_size) + 10)
+
+/* The size of an ext2 block in bytes. */
+#define EXT2_BLOCK_SIZE(data) (1 << LOG2_BLOCK_SIZE (data))
+
+/* The revision level. */
+#define EXT2_REVISION(data) grub_le_to_cpu32 (data->sblock.revision_level)
+
+/* The inode size. */
+#define EXT2_INODE_SIZE(data) \
+ (EXT2_REVISION (data) == EXT2_GOOD_OLD_REVISION \
+ ? EXT2_GOOD_OLD_INODE_SIZE \
+ : grub_le_to_cpu16 (data->sblock.inode_size))
+
+/* Superblock filesystem feature flags (RW compatible)
+ * A filesystem with any of these enabled can be read and written by a driver
+ * that does not understand them without causing metadata/data corruption. */
+#define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
+#define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
+#define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
+#define EXT2_FEATURE_COMPAT_RESIZE_INODE 0x0010
+#define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
+/* Superblock filesystem feature flags (RO compatible)
+ * A filesystem with any of these enabled can be safely read by a driver that
+ * does not understand them, but should not be written to, usually because
+ * additional metadata is required. */
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
+#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
+#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
+#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
+/* Superblock filesystem feature flags (back-incompatible)
+ * A filesystem with any of these enabled should not be attempted to be read
+ * by a driver that does not understand them, since they usually indicate
+ * metadata format changes that might confuse the reader. */
+#define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
+#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Volume is journal device */
+#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040 /* Extents used */
+#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
+#define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
+
+/* The set of back-incompatible features this driver DOES support. Add (OR)
+ * flags here as the related features are implemented into the driver. */
+#define EXT2_DRIVER_SUPPORTED_INCOMPAT ( EXT2_FEATURE_INCOMPAT_FILETYPE \
+ | EXT4_FEATURE_INCOMPAT_EXTENTS \
+ | EXT4_FEATURE_INCOMPAT_FLEX_BG )
+/* List of rationales for the ignored "incompatible" features:
+ * needs_recovery: Not really back-incompatible - was added as such to forbid
+ * ext2 drivers from mounting an ext3 volume with a dirty
+ * journal because they will ignore the journal, but the next
+ * ext3 driver to mount the volume will find the journal and
+ * replay it, potentially corrupting the metadata written by
+ * the ext2 drivers. Safe to ignore for this RO driver. */
+#define EXT2_DRIVER_IGNORED_INCOMPAT ( EXT3_FEATURE_INCOMPAT_RECOVER )
+
+
+#define EXT3_JOURNAL_MAGIC_NUMBER 0xc03b3998U
+
+#define EXT3_JOURNAL_DESCRIPTOR_BLOCK 1
+#define EXT3_JOURNAL_COMMIT_BLOCK 2
+#define EXT3_JOURNAL_SUPERBLOCK_V1 3
+#define EXT3_JOURNAL_SUPERBLOCK_V2 4
+#define EXT3_JOURNAL_REVOKE_BLOCK 5
+
+#define EXT3_JOURNAL_FLAG_ESCAPE 1
+#define EXT3_JOURNAL_FLAG_SAME_UUID 2
+#define EXT3_JOURNAL_FLAG_DELETED 4
+#define EXT3_JOURNAL_FLAG_LAST_TAG 8
+
+#define EXT4_EXTENTS_FLAG 0x80000
+
+/* The ext2 superblock. */
+struct grub_ext2_sblock
+{
+ grub_uint32_t total_inodes;
+ grub_uint32_t total_blocks;
+ grub_uint32_t reserved_blocks;
+ grub_uint32_t free_blocks;
+ grub_uint32_t free_inodes;
+ grub_uint32_t first_data_block;
+ grub_uint32_t log2_block_size;
+ grub_uint32_t log2_fragment_size;
+ grub_uint32_t blocks_per_group;
+ grub_uint32_t fragments_per_group;
+ grub_uint32_t inodes_per_group;
+ grub_uint32_t mtime;
+ grub_uint32_t utime;
+ grub_uint16_t mnt_count;
+ grub_uint16_t max_mnt_count;
+ grub_uint16_t magic;
+ grub_uint16_t fs_state;
+ grub_uint16_t error_handling;
+ grub_uint16_t minor_revision_level;
+ grub_uint32_t lastcheck;
+ grub_uint32_t checkinterval;
+ grub_uint32_t creator_os;
+ grub_uint32_t revision_level;
+ grub_uint16_t uid_reserved;
+ grub_uint16_t gid_reserved;
+ grub_uint32_t first_inode;
+ grub_uint16_t inode_size;
+ grub_uint16_t block_group_number;
+ grub_uint32_t feature_compatibility;
+ grub_uint32_t feature_incompat;
+ grub_uint32_t feature_ro_compat;
+ grub_uint16_t uuid[8];
+ char volume_name[16];
+ char last_mounted_on[64];
+ grub_uint32_t compression_info;
+ grub_uint8_t prealloc_blocks;
+ grub_uint8_t prealloc_dir_blocks;
+ grub_uint16_t reserved_gdt_blocks;
+ grub_uint8_t journal_uuid[16];
+ grub_uint32_t journal_inum;
+ grub_uint32_t journal_dev;
+ grub_uint32_t last_orphan;
+ grub_uint32_t hash_seed[4];
+ grub_uint8_t def_hash_version;
+ grub_uint8_t jnl_backup_type;
+ grub_uint16_t reserved_word_pad;
+ grub_uint32_t default_mount_opts;
+ grub_uint32_t first_meta_bg;
+ grub_uint32_t mkfs_time;
+ grub_uint32_t jnl_blocks[17];
+};
+
+/* The ext2 blockgroup. */
+struct grub_ext2_block_group
+{
+ grub_uint32_t block_id;
+ grub_uint32_t inode_id;
+ grub_uint32_t inode_table_id;
+ grub_uint16_t free_blocks;
+ grub_uint16_t free_inodes;
+ grub_uint16_t used_dirs;
+ grub_uint16_t pad;
+ grub_uint32_t reserved[3];
+};
+
+/* The ext2 inode. */
+struct grub_ext2_inode
+{
+ grub_uint16_t mode;
+ grub_uint16_t uid;
+ grub_uint32_t size;
+ grub_uint32_t atime;
+ grub_uint32_t ctime;
+ grub_uint32_t mtime;
+ grub_uint32_t dtime;
+ grub_uint16_t gid;
+ grub_uint16_t nlinks;
+ grub_uint32_t blockcnt; /* Blocks of 512 bytes!! */
+ grub_uint32_t flags;
+ grub_uint32_t osd1;
+ union
+ {
+ struct datablocks
+ {
+ grub_uint32_t dir_blocks[INDIRECT_BLOCKS];
+ grub_uint32_t indir_block;
+ grub_uint32_t double_indir_block;
+ grub_uint32_t triple_indir_block;
+ } blocks;
+ char symlink[60];
+ };
+ grub_uint32_t version;
+ grub_uint32_t acl;
+ grub_uint32_t size_high;
+ grub_uint32_t fragment_addr;
+ grub_uint32_t osd2[3];
+};
+
+/* The header of an ext2 directory entry. */
+struct ext2_dirent
+{
+ grub_uint32_t inode;
+ grub_uint16_t direntlen;
+ grub_uint8_t namelen;
+ grub_uint8_t filetype;
+};
+
+struct grub_ext3_journal_header
+{
+ grub_uint32_t magic;
+ grub_uint32_t block_type;
+ grub_uint32_t sequence;
+};
+
+struct grub_ext3_journal_revoke_header
+{
+ struct grub_ext3_journal_header header;
+ grub_uint32_t count;
+ grub_uint32_t data[0];
+};
+
+struct grub_ext3_journal_block_tag
+{
+ grub_uint32_t block;
+ grub_uint32_t flags;
+};
+
+struct grub_ext3_journal_sblock
+{
+ struct grub_ext3_journal_header header;
+ grub_uint32_t block_size;
+ grub_uint32_t maxlen;
+ grub_uint32_t first;
+ grub_uint32_t sequence;
+ grub_uint32_t start;
+};
+
+#define EXT4_EXT_MAGIC 0xf30a
+
+struct grub_ext4_extent_header
+{
+ grub_uint16_t magic;
+ grub_uint16_t entries;
+ grub_uint16_t max;
+ grub_uint16_t depth;
+ grub_uint32_t generation;
+};
+
+struct grub_ext4_extent
+{
+ grub_uint32_t block;
+ grub_uint16_t len;
+ grub_uint16_t start_hi;
+ grub_uint32_t start;
+};
+
+struct grub_ext4_extent_idx
+{
+ grub_uint32_t block;
+ grub_uint32_t leaf;
+ grub_uint16_t leaf_hi;
+ grub_uint16_t unused;
+};
+
+struct grub_fshelp_node
+{
+ struct grub_ext2_data *data;
+ struct grub_ext2_inode inode;
+ int ino;
+ int inode_read;
+};
+
+/* Information about a "mounted" ext2 filesystem. */
+struct grub_ext2_data
+{
+ struct grub_ext2_sblock sblock;
+ grub_disk_t disk;
+ struct grub_ext2_inode *inode;
+ struct grub_fshelp_node diropen;
+};
+
+static grub_dl_t my_mod;
+
+
+
+/* Read into BLKGRP the blockgroup descriptor of blockgroup GROUP of
+ the mounted filesystem DATA. */
+inline static grub_err_t
+grub_ext2_blockgroup (struct grub_ext2_data *data, int group,
+ struct grub_ext2_block_group *blkgrp)
+{
+ return grub_disk_read (data->disk,
+ ((grub_le_to_cpu32 (data->sblock.first_data_block) + 1)
+ << LOG2_EXT2_BLOCK_SIZE (data)),
+ group * sizeof (struct grub_ext2_block_group),
+ sizeof (struct grub_ext2_block_group), blkgrp);
+}
+
+static struct grub_ext4_extent_header *
+grub_ext4_find_leaf (struct grub_ext2_data *data, char *buf,
+ struct grub_ext4_extent_header *ext_block,
+ grub_uint32_t fileblock)
+{
+ struct grub_ext4_extent_idx *index;
+
+ while (1)
+ {
+ int i;
+ grub_disk_addr_t block;
+
+ index = (struct grub_ext4_extent_idx *) (ext_block + 1);
+
+ if (grub_le_to_cpu16(ext_block->magic) != EXT4_EXT_MAGIC)
+ return 0;
+
+ if (ext_block->depth == 0)
+ return ext_block;
+
+ for (i = 0; i < grub_le_to_cpu16 (ext_block->entries); i++)
+ {
+ if (fileblock < grub_le_to_cpu32(index[i].block))
+ break;
+ }
+
+ if (--i < 0)
+ return 0;
+
+ block = grub_le_to_cpu16 (index[i].leaf_hi);
+ block = (block << 32) + grub_le_to_cpu32 (index[i].leaf);
+ if (grub_disk_read (data->disk,
+ block << LOG2_EXT2_BLOCK_SIZE (data),
+ 0, EXT2_BLOCK_SIZE(data), buf))
+ return 0;
+
+ ext_block = (struct grub_ext4_extent_header *) buf;
+ }
+}
+
+static grub_disk_addr_t
+grub_ext2_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
+{
+ struct grub_ext2_data *data = node->data;
+ struct grub_ext2_inode *inode = &node->inode;
+ int blknr = -1;
+ unsigned int blksz = EXT2_BLOCK_SIZE (data);
+ int log2_blksz = LOG2_EXT2_BLOCK_SIZE (data);
+
+ if (grub_le_to_cpu32(inode->flags) & EXT4_EXTENTS_FLAG)
+ {
+ char buf[EXT2_BLOCK_SIZE(data)];
+ struct grub_ext4_extent_header *leaf;
+ struct grub_ext4_extent *ext;
+ int i;
+
+ leaf = grub_ext4_find_leaf (data, buf,
+ (struct grub_ext4_extent_header *) inode->blocks.dir_blocks,
+ fileblock);
+ if (! leaf)
+ {
+ grub_error (GRUB_ERR_BAD_FS, "invalid extent");
+ return -1;
+ }
+
+ ext = (struct grub_ext4_extent *) (leaf + 1);
+ for (i = 0; i < grub_le_to_cpu16 (leaf->entries); i++)
+ {
+ if (fileblock < grub_le_to_cpu32 (ext[i].block))
+ break;
+ }
+
+ if (--i >= 0)
+ {
+ fileblock -= grub_le_to_cpu32 (ext[i].block);
+ if (fileblock >= grub_le_to_cpu16 (ext[i].len))
+ return 0;
+ else
+ {
+ grub_disk_addr_t start;
+
+ start = grub_le_to_cpu16 (ext[i].start_hi);
+ start = (start << 32) + grub_le_to_cpu32 (ext[i].start);
+
+ return fileblock + start;
+ }
+ }
+ else
+ {
+ grub_error (GRUB_ERR_BAD_FS, "something wrong with extent");
+ return -1;
+ }
+ }
+ /* Direct blocks. */
+ if (fileblock < INDIRECT_BLOCKS)
+ blknr = grub_le_to_cpu32 (inode->blocks.dir_blocks[fileblock]);
+ /* Indirect. */
+ else if (fileblock < INDIRECT_BLOCKS + blksz / 4)
+ {
+ grub_uint32_t indir[blksz / 4];
+
+ if (grub_disk_read (data->disk,
+ ((grub_disk_addr_t)
+ grub_le_to_cpu32 (inode->blocks.indir_block))
+ << log2_blksz,
+ 0, blksz, indir))
+ return grub_errno;
+
+ blknr = grub_le_to_cpu32 (indir[fileblock - INDIRECT_BLOCKS]);
+ }
+ /* Double indirect. */
+ else if (fileblock < INDIRECT_BLOCKS + blksz / 4 * (blksz / 4 + 1))
+ {
+ unsigned int perblock = blksz / 4;
+ unsigned int rblock = fileblock - (INDIRECT_BLOCKS
+ + blksz / 4);
+ grub_uint32_t indir[blksz / 4];
+
+ if (grub_disk_read (data->disk,
+ ((grub_disk_addr_t)
+ grub_le_to_cpu32 (inode->blocks.double_indir_block))
+ << log2_blksz,
+ 0, blksz, indir))
+ return grub_errno;
+
+ if (grub_disk_read (data->disk,
+ ((grub_disk_addr_t)
+ grub_le_to_cpu32 (indir[rblock / perblock]))
+ << log2_blksz,
+ 0, blksz, indir))
+ return grub_errno;
+
+
+ blknr = grub_le_to_cpu32 (indir[rblock % perblock]);
+ }
+ /* triple indirect. */
+ else if (fileblock < INDIRECT_BLOCKS + blksz / 4 * (blksz / 4 + 1)
+ + (blksz / 4) * (blksz / 4) * (blksz / 4 + 1))
+ {
+ unsigned int perblock = blksz / 4;
+ unsigned int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4
+ * (blksz / 4 + 1));
+ grub_uint32_t indir[blksz / 4];
+
+ if (grub_disk_read (data->disk,
+ ((grub_disk_addr_t)
+ grub_le_to_cpu32 (inode->blocks.triple_indir_block))
+ << log2_blksz,
+ 0, blksz, indir))
+ return grub_errno;
+
+ if (grub_disk_read (data->disk,
+ ((grub_disk_addr_t)
+ grub_le_to_cpu32 (indir[(rblock / perblock) / perblock]))
+ << log2_blksz,
+ 0, blksz, indir))
+ return grub_errno;
+
+ if (grub_disk_read (data->disk,
+ ((grub_disk_addr_t)
+ grub_le_to_cpu32 (indir[(rblock / perblock) % perblock]))
+ << log2_blksz,
+ 0, blksz, indir))
+ return grub_errno;
+
+ blknr = grub_le_to_cpu32 (indir[rblock % perblock]);
+ }
+ else
+ {
+ grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
+ "ext2fs doesn't support quadruple indirect blocks");
+ }
+
+ return blknr;
+}
+
+/* Read LEN bytes from the file described by DATA starting with byte
+ POS. Return the amount of read bytes in READ. */
+static grub_ssize_t
+grub_ext2_read_file (grub_fshelp_node_t node,
+ void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
+ unsigned offset, unsigned length),
+ grub_off_t pos, grub_size_t len, char *buf)
+{
+ return grub_fshelp_read_file (node->data->disk, node, read_hook,
+ pos, len, buf, grub_ext2_read_block,
+ grub_cpu_to_le32 (node->inode.size)
+ | (((grub_off_t) grub_cpu_to_le32 (node->inode.size_high)) << 32),
+ LOG2_EXT2_BLOCK_SIZE (node->data));
+
+}
+
+
+/* Read the inode INO for the file described by DATA into INODE. */
+static grub_err_t
+grub_ext2_read_inode (struct grub_ext2_data *data,
+ int ino, struct grub_ext2_inode *inode)
+{
+ struct grub_ext2_block_group blkgrp;
+ struct grub_ext2_sblock *sblock = &data->sblock;
+ int inodes_per_block;
+ unsigned int blkno;
+ unsigned int blkoff;
+
+ /* It is easier to calculate if the first inode is 0. */
+ ino--;
+
+ grub_ext2_blockgroup (data,
+ ino / grub_le_to_cpu32 (sblock->inodes_per_group),
+ &blkgrp);
+ if (grub_errno)
+ return grub_errno;
+
+ inodes_per_block = EXT2_BLOCK_SIZE (data) / EXT2_INODE_SIZE (data);
+ blkno = (ino % grub_le_to_cpu32 (sblock->inodes_per_group))
+ / inodes_per_block;
+ blkoff = (ino % grub_le_to_cpu32 (sblock->inodes_per_group))
+ % inodes_per_block;
+
+ /* Read the inode. */
+ if (grub_disk_read (data->disk,
+ (((grub_disk_addr_t) grub_le_to_cpu32 (blkgrp.inode_table_id) + blkno)
+ << LOG2_EXT2_BLOCK_SIZE (data)),
+ EXT2_INODE_SIZE (data) * blkoff,
+ sizeof (struct grub_ext2_inode), inode))
+ return grub_errno;
+
+ return 0;
+}
+
+static struct grub_ext2_data *
+grub_ext2_mount (grub_disk_t disk)
+{
+ struct grub_ext2_data *data;
+
+ data = grub_malloc (sizeof (struct grub_ext2_data));
+ if (!data)
+ return 0;
+
+ /* Read the superblock. */
+ grub_disk_read (disk, 1 * 2, 0, sizeof (struct grub_ext2_sblock),
+ &data->sblock);
+ if (grub_errno)
+ goto fail;
+
+ /* Make sure this is an ext2 filesystem. */
+ if (grub_le_to_cpu16 (data->sblock.magic) != EXT2_MAGIC)
+ {
+ grub_error (GRUB_ERR_BAD_FS, "not an ext2 filesystem");
+ goto fail;
+ }
+
+ /* Check the FS doesn't have feature bits enabled that we don't support. */
+ if (grub_le_to_cpu32 (data->sblock.feature_incompat)
+ & ~(EXT2_DRIVER_SUPPORTED_INCOMPAT | EXT2_DRIVER_IGNORED_INCOMPAT))
+ {
+ grub_error (GRUB_ERR_BAD_FS, "filesystem has unsupported incompatible features");
+ goto fail;
+ }
+
+
+ data->disk = disk;
+
+ data->diropen.data = data;
+ data->diropen.ino = 2;
+ data->diropen.inode_read = 1;
+
+ data->inode = &data->diropen.inode;
+
+ grub_ext2_read_inode (data, 2, data->inode);
+ if (grub_errno)
+ goto fail;
+
+ return data;
+
+ fail:
+ if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
+ grub_error (GRUB_ERR_BAD_FS, "not an ext2 filesystem");
+
+ grub_free (data);
+ return 0;
+}
+
+static char *
+grub_ext2_read_symlink (grub_fshelp_node_t node)
+{
+ char *symlink;
+ struct grub_fshelp_node *diro = node;
+
+ if (! diro->inode_read)
+ {
+ grub_ext2_read_inode (diro->data, diro->ino, &diro->inode);
+ if (grub_errno)
+ return 0;
+ }
+
+ symlink = grub_malloc (grub_le_to_cpu32 (diro->inode.size) + 1);
+ if (! symlink)
+ return 0;
+
+ /* If the filesize of the symlink is bigger than
+ 60 the symlink is stored in a separate block,
+ otherwise it is stored in the inode. */
+ if (grub_le_to_cpu32 (diro->inode.size) <= 60)
+ grub_strncpy (symlink,
+ diro->inode.symlink,
+ grub_le_to_cpu32 (diro->inode.size));
+ else
+ {
+ grub_ext2_read_file (diro, 0, 0,
+ grub_le_to_cpu32 (diro->inode.size),
+ symlink);
+ if (grub_errno)
+ {
+ grub_free (symlink);
+ return 0;
+ }
+ }
+
+ symlink[grub_le_to_cpu32 (diro->inode.size)] = '\0';
+ return symlink;
+}
+
+static int
+grub_ext2_iterate_dir (grub_fshelp_node_t dir,
+ int NESTED_FUNC_ATTR
+ (*hook) (const char *filename,
+ enum grub_fshelp_filetype filetype,
+ grub_fshelp_node_t node))
+{
+ unsigned int fpos = 0;
+ struct grub_fshelp_node *diro = (struct grub_fshelp_node *) dir;
+
+ if (! diro->inode_read)
+ {
+ grub_ext2_read_inode (diro->data, diro->ino, &diro->inode);
+ if (grub_errno)
+ return 0;
+ }
+
+ /* Search the file. */
+ while (fpos < grub_le_to_cpu32 (diro->inode.size))
+ {
+ struct ext2_dirent dirent;
+
+ grub_ext2_read_file (diro, 0, fpos, sizeof (struct ext2_dirent),
+ (char *) &dirent);
+ if (grub_errno)
+ return 0;
+
+ if (dirent.direntlen == 0)
+ return 0;
+
+ if (dirent.namelen != 0)
+ {
+ char filename[dirent.namelen + 1];
+ struct grub_fshelp_node *fdiro;
+ enum grub_fshelp_filetype type = GRUB_FSHELP_UNKNOWN;
+
+ grub_ext2_read_file (diro, 0, fpos + sizeof (struct ext2_dirent),
+ dirent.namelen, filename);
+ if (grub_errno)
+ return 0;
+
+ fdiro = grub_malloc (sizeof (struct grub_fshelp_node));
+ if (! fdiro)
+ return 0;
+
+ fdiro->data = diro->data;
+ fdiro->ino = grub_le_to_cpu32 (dirent.inode);
+
+ filename[dirent.namelen] = '\0';
+
+ if (dirent.filetype != FILETYPE_UNKNOWN)
+ {
+ fdiro->inode_read = 0;
+
+ if (dirent.filetype == FILETYPE_DIRECTORY)
+ type = GRUB_FSHELP_DIR;
+ else if (dirent.filetype == FILETYPE_SYMLINK)
+ type = GRUB_FSHELP_SYMLINK;
+ else if (dirent.filetype == FILETYPE_REG)
+ type = GRUB_FSHELP_REG;
+ }
+ else
+ {
+ /* The filetype can not be read from the dirent, read
+ the inode to get more information. */
+ grub_ext2_read_inode (diro->data,
+ grub_le_to_cpu32 (dirent.inode),
+ &fdiro->inode);
+ if (grub_errno)
+ {
+ grub_free (fdiro);
+ return 0;
+ }
+
+ fdiro->inode_read = 1;
+
+ if ((grub_le_to_cpu16 (fdiro->inode.mode)
+ & FILETYPE_INO_MASK) == FILETYPE_INO_DIRECTORY)
+ type = GRUB_FSHELP_DIR;
+ else if ((grub_le_to_cpu16 (fdiro->inode.mode)
+ & FILETYPE_INO_MASK) == FILETYPE_INO_SYMLINK)
+ type = GRUB_FSHELP_SYMLINK;
+ else if ((grub_le_to_cpu16 (fdiro->inode.mode)
+ & FILETYPE_INO_MASK) == FILETYPE_INO_REG)
+ type = GRUB_FSHELP_REG;
+ }
+
+ if (hook (filename, type, fdiro))
+ return 1;
+ }
+
+ fpos += grub_le_to_cpu16 (dirent.direntlen);
+ }
+
+ return 0;
+}
+
+/* Open a file named NAME and initialize FILE. */
+static grub_err_t
+grub_ext2_open (struct grub_file *file, const char *name)
+{
+ struct grub_ext2_data *data;
+ struct grub_fshelp_node *fdiro = 0;
+ grub_err_t err;
+
+ grub_dl_ref (my_mod);
+
+ data = grub_ext2_mount (file->device->disk);
+ if (! data)
+ {
+ err = grub_errno;
+ goto fail;
+ }
+
+ err = grub_fshelp_find_file (name, &data->diropen, &fdiro,
+ grub_ext2_iterate_dir,
+ grub_ext2_read_symlink, GRUB_FSHELP_REG);
+ if (err)
+ goto fail;
+
+ if (! fdiro->inode_read)
+ {
+ err = grub_ext2_read_inode (data, fdiro->ino, &fdiro->inode);
+ if (err)
+ goto fail;
+ }
+
+ grub_memcpy (data->inode, &fdiro->inode, sizeof (struct grub_ext2_inode));
+ grub_free (fdiro);
+
+ file->size = grub_le_to_cpu32 (data->inode->size);
+ file->size |= ((grub_off_t) grub_le_to_cpu32 (data->inode->size_high)) << 32;
+ file->data = data;
+ file->offset = 0;
+
+ return 0;
+
+ fail:
+ if (fdiro != &data->diropen)
+ grub_free (fdiro);
+ grub_free (data);
+
+ grub_dl_unref (my_mod);
+
+ return err;
+}
+
+static grub_err_t
+grub_ext2_close (grub_file_t file)
+{
+ grub_free (file->data);
+
+ grub_dl_unref (my_mod);
+
+ return GRUB_ERR_NONE;
+}
+
+/* Read LEN bytes data from FILE into BUF. */
+static grub_ssize_t
+grub_ext2_read (grub_file_t file, char *buf, grub_size_t len)
+{
+ struct grub_ext2_data *data = (struct grub_ext2_data *) file->data;
+
+ return grub_ext2_read_file (&data->diropen, file->read_hook,
+ file->offset, len, buf);
+}
+
+
+static grub_err_t
+grub_ext2_dir (grub_device_t device, const char *path,
+ int (*hook) (const char *filename,
+ const struct grub_dirhook_info *info))
+{
+ struct grub_ext2_data *data = 0;
+ struct grub_fshelp_node *fdiro = 0;
+
+ auto int NESTED_FUNC_ATTR iterate (const char *filename,
+ enum grub_fshelp_filetype filetype,
+ grub_fshelp_node_t node);
+
+ int NESTED_FUNC_ATTR iterate (const char *filename,
+ enum grub_fshelp_filetype filetype,
+ grub_fshelp_node_t node)
+ {
+ struct grub_dirhook_info info;
+ grub_memset (&info, 0, sizeof (info));
+ if (! node->inode_read)
+ {
+ grub_ext2_read_inode (data, node->ino, &node->inode);
+ if (!grub_errno)
+ node->inode_read = 1;
+ grub_errno = GRUB_ERR_NONE;
+ }
+ if (node->inode_read)
+ {
+ info.mtimeset = 1;
+ info.mtime = grub_le_to_cpu32 (node->inode.mtime);
+ }
+
+ info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
+ grub_free (node);
+ return hook (filename, &info);
+ }
+
+ grub_dl_ref (my_mod);
+
+ data = grub_ext2_mount (device->disk);
+ if (! data)
+ goto fail;
+
+ grub_fshelp_find_file (path, &data->diropen, &fdiro, grub_ext2_iterate_dir,
+ grub_ext2_read_symlink, GRUB_FSHELP_DIR);
+ if (grub_errno)
+ goto fail;
+
+ grub_ext2_iterate_dir (fdiro, iterate);
+
+ fail:
+ if (fdiro != &data->diropen)
+ grub_free (fdiro);
+ grub_free (data);
+
+ grub_dl_unref (my_mod);
+
+ return grub_errno;
+}
+
+static grub_err_t
+grub_ext2_label (grub_device_t device, char **label)
+{
+ struct grub_ext2_data *data;
+ grub_disk_t disk = device->disk;
+
+ grub_dl_ref (my_mod);
+
+ data = grub_ext2_mount (disk);
+ if (data)
+ *label = grub_strndup (data->sblock.volume_name, 14);
+ else
+ *label = NULL;
+
+ grub_dl_unref (my_mod);
+
+ grub_free (data);
+
+ return grub_errno;
+}
+
+static grub_err_t
+grub_ext2_uuid (grub_device_t device, char **uuid)
+{
+ struct grub_ext2_data *data;
+ grub_disk_t disk = device->disk;
+
+ grub_dl_ref (my_mod);
+
+ data = grub_ext2_mount (disk);
+ if (data)
+ {
+ *uuid = grub_xasprintf ("%04x%04x-%04x-%04x-%04x-%04x%04x%04x",
+ grub_be_to_cpu16 (data->sblock.uuid[0]),
+ grub_be_to_cpu16 (data->sblock.uuid[1]),
+ grub_be_to_cpu16 (data->sblock.uuid[2]),
+ grub_be_to_cpu16 (data->sblock.uuid[3]),
+ grub_be_to_cpu16 (data->sblock.uuid[4]),
+ grub_be_to_cpu16 (data->sblock.uuid[5]),
+ grub_be_to_cpu16 (data->sblock.uuid[6]),
+ grub_be_to_cpu16 (data->sblock.uuid[7]));
+ }
+ else
+ *uuid = NULL;
+
+ grub_dl_unref (my_mod);
+
+ grub_free (data);
+
+ return grub_errno;
+}
+
+/* Get mtime. */
+static grub_err_t
+grub_ext2_mtime (grub_device_t device, grub_int32_t *tm)
+{
+ struct grub_ext2_data *data;
+ grub_disk_t disk = device->disk;
+
+ grub_dl_ref (my_mod);
+
+ data = grub_ext2_mount (disk);
+ if (!data)
+ *tm = 0;
+ else
+ *tm = grub_le_to_cpu32 (data->sblock.utime);
+
+ grub_dl_unref (my_mod);
+
+ grub_free (data);
+
+ return grub_errno;
+
+}
+
+
+
+static struct grub_fs grub_ext2_fs =
+ {
+ .name = "ext2",
+ .dir = grub_ext2_dir,
+ .open = grub_ext2_open,
+ .read = grub_ext2_read,
+ .close = grub_ext2_close,
+ .label = grub_ext2_label,
+ .uuid = grub_ext2_uuid,
+ .mtime = grub_ext2_mtime,
+#ifdef GRUB_UTIL
+ .reserved_first_sector = 1,
+#endif
+ .next = 0
+ };
+
+GRUB_MOD_INIT(ext2)
+{
+ grub_fs_register (&grub_ext2_fs);
+ my_mod = mod;
+}
+
+GRUB_MOD_FINI(ext2)
+{
+ grub_fs_unregister (&grub_ext2_fs);
+}