ext4: Don't allow nonextenst mount option for large filesystem (c07651b5) · Commits · 戴 / test

The block mapped inode format can address only blocks within 2**32. This causes a number of issues, the biggest of which is that the block allocator needs to be taught that certain inodes can not utilize block numbers > 2**32. So until this is fixed, it is simplest to fail mounting of file systems with more than 2**32 blocks if the -o noextents option is given. Signed-off-by:

Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:

Mingming Cao <cmm@us.ibm.com> Signed-off-by:

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

fs/ext4/super.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -1004,6 +1004,7 @@ static int parse_options (char options, struct super_block sb,
		int qtype, qfmt;
		char *qname;
		#endif
		ext4_fsblk_t last_block;

		if (!options)
		return 1;
		@@ -1326,6 +1327,20 @@ set_qf_format:
		set_opt (sbi->s_mount_opt, EXTENTS);
		break;
		case Opt_noextents:
		/*
		* When e2fsprogs support resizing an already existing
		* ext3 file system to greater than 2**32 we need to
		* add support to block allocator to handle growing
		* already existing block mapped inode so that blocks
		* allocated for them fall within 2**32
		*/
		last_block = ext4_blocks_count(sbi->s_es) - 1;
		if (last_block > 0xffffffffULL) {
		printk(KERN_ERR "EXT4-fs: Filesystem too "
		"large to mount with "
		"-o noextents options\n");
		return 0;
		}
		clear_opt (sbi->s_mount_opt, EXTENTS);
		break;
		case Opt_i_version:

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