ext4: kill i_version support for Hurd-castrated file systems (c4f65706) · Commits · 戴 / test

The Hurd file system uses uses the inode field which is now used for i_version for its translator block. This means that ext2 file systems that are formatted for GNU Hurd can't be used to support NFSv4. Given that Hurd file systems don't support extents, and a huge number of modern file system features, this is no great loss. If we don't do this, the attempt to update the i_version field will stomp over the translator block field, which will cause file system corruption for Hurd file systems. This can be replicated via: mke2fs -t ext2 -o hurd /dev/vdc mount -t ext4 /dev/vdc /vdc touch /vdc/bug0000 umount /dev/vdc e2fsck -f /dev/vdc Addresses-Debian-Bug: #738758 Reported-By:

Gabriele Giacone <1o5g4r8o@gmail.com> Signed-off-by:

"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/inode.c

+18 −11

Original line number	Diff line number	Diff line
		@@ -4168,12 +4168,15 @@ struct inode ext4_iget(struct super_block sb, unsigned long ino)
		EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
		EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);

		if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
		cpu_to_le32(EXT4_OS_HURD)) {
		inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
		if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
		if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
		inode->i_version \|=
		(__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
		}
		}

		ret = 0;
		if (ei->i_file_acl &&
		@@ -4388,12 +4391,16 @@ static int ext4_do_update_inode(handle_t *handle,
		raw_inode->i_block[block] = ei->i_data[block];
		}

		if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
		cpu_to_le32(EXT4_OS_HURD)) {
		raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
		if (ei->i_extra_isize) {
		if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
		raw_inode->i_version_hi =
		cpu_to_le32(inode->i_version >> 32);
		raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
		raw_inode->i_extra_isize =
		cpu_to_le16(ei->i_extra_isize);
		}
		}

		ext4_inode_csum_set(inode, raw_inode, ei);

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