md: Relax minimum size restrictions on chunk_size.

Currently, the 'chunk_size' of an array must be at-least PAGE_SIZE.

This makes moving an array to a machine with a larger PAGE_SIZE, or
changing the kernel to use a larger PAGE_SIZE, can stop an array from
working.

For RAID10 and RAID4/5/6, this is non-trivial to fix as the resync
process works on whole pages at a time, and assumes them to be wholly
within a stripe.  For other raid personalities, this restriction is
not needed at all and can be dropped.

So remove the test on chunk_size from common can, and add it in just
the places where it is needed: raid10 and raid4/5/6.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2008-10-13 11:55:12 +11:00
parent d710e13812
commit 4bbf3771ca
3 changed files with 11 additions and 8 deletions

View File

@ -3520,17 +3520,12 @@ static int do_md_run(mddev_t * mddev)
return -EINVAL;
}
/*
* chunk-size has to be a power of 2 and multiples of PAGE_SIZE
* chunk-size has to be a power of 2
*/
if ( (1 << ffz(~chunk_size)) != chunk_size) {
printk(KERN_ERR "chunk_size of %d not valid\n", chunk_size);
return -EINVAL;
}
if (chunk_size < PAGE_SIZE) {
printk(KERN_ERR "too small chunk_size: %d < %ld\n",
chunk_size, PAGE_SIZE);
return -EINVAL;
}
/* devices must have minimum size of one chunk */
rdev_for_each(rdev, tmp, mddev) {

View File

@ -2028,8 +2028,9 @@ static int run(mddev_t *mddev)
int nc, fc, fo;
sector_t stride, size;
if (mddev->chunk_size == 0) {
printk(KERN_ERR "md/raid10: non-zero chunk size required.\n");
if (mddev->chunk_size < PAGE_SIZE) {
printk(KERN_ERR "md/raid10: chunk size must be "
"at least PAGE_SIZE(%ld).\n", PAGE_SIZE);
return -EINVAL;
}

View File

@ -4007,6 +4007,13 @@ static int run(mddev_t *mddev)
return -EIO;
}
if (mddev->chunk_size < PAGE_SIZE) {
printk(KERN_ERR "md/raid5: chunk_size must be at least "
"PAGE_SIZE but %d < %ld\n",
mddev->chunk_size, PAGE_SIZE);
return -EINVAL;
}
if (mddev->reshape_position != MaxSector) {
/* Check that we can continue the reshape.
* Currently only disks can change, it must