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Commit c07651b5 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o
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ext4: Don't allow nonextenst mount option for large filesystem 



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: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarMingming Cao <cmm@us.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent dd919b98

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 @@ static int parse_options (char *options, struct super_block *sb, 
			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: