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: 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>
This commit is contained in:
Aneesh Kumar K.V 2008-07-11 19:27:31 -04:00 committed by Theodore Ts'o
parent dd919b9822
commit c07651b556

View File

@ -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: