void ocfs2_la_set_sizes(struct ocfs2_super *osb, int requested_mb)
{
struct super_block *sb = osb->sb;
unsigned int la_default_mb = ocfs2_la_default_mb(osb);
unsigned int la_max_mb;
la_max_mb = ocfs2_clusters_to_megabytes(sb,
ocfs2_local_alloc_size(sb) * 8);
trace_ocfs2_la_set_sizes(requested_mb, la_max_mb, la_default_mb);
if (requested_mb == -1) {
/* No user request - use defaults */
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, la_default_mb);
} else if (requested_mb > la_max_mb) {
/* Request is too big, we give the maximum available */
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, la_max_mb);
} else {
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, requested_mb);
}
osb->local_alloc_bits = osb->local_alloc_default_bits;
}
void ocfs2_la_set_sizes(struct ocfs2_super *osb, int requested_mb)
{
struct super_block *sb = osb->sb;
unsigned int la_default_mb = ocfs2_la_default_mb(osb);
unsigned int la_max_mb;
la_max_mb = ocfs2_clusters_to_megabytes(sb,
ocfs2_local_alloc_size(sb) * 8);
trace_ocfs2_la_set_sizes(requested_mb, la_max_mb, la_default_mb);
if (requested_mb == -1) {
/* */
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, la_default_mb);
} else if (requested_mb > la_max_mb) {
/* */
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, la_max_mb);
} else {
osb->local_alloc_default_bits =
ocfs2_megabytes_to_clusters(sb, requested_mb);
}
osb->local_alloc_bits = osb->local_alloc_default_bits;
}
unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
{
unsigned int la_mb;
unsigned int gd_mb;
unsigned int la_max_mb;
unsigned int megs_per_slot;
struct super_block *sb = osb->sb;
gd_mb = ocfs2_clusters_to_megabytes(osb->sb,
8 * ocfs2_group_bitmap_size(sb, 0, osb->s_feature_incompat));
/*
* This takes care of files systems with very small group
* descriptors - 512 byte blocksize at cluster sizes lower
* than 16K and also 1k blocksize with 4k cluster size.
*/
if ((sb->s_blocksize == 512 && osb->s_clustersize <= 8192)
|| (sb->s_blocksize == 1024 && osb->s_clustersize == 4096))
return OCFS2_LA_OLD_DEFAULT;
/*
* Leave enough room for some block groups and make the final
* value we work from a multiple of 4.
*/
gd_mb -= 16;
gd_mb &= 0xFFFFFFFB;
la_mb = gd_mb;
/*
* Keep window sizes down to a reasonable default
*/
if (la_mb > OCFS2_LA_MAX_DEFAULT_MB) {
/*
* Some clustersize / blocksize combinations will have
* given us a larger than OCFS2_LA_MAX_DEFAULT_MB
* default size, but get poor distribution when
* limited to exactly 256 megabytes.
*
* As an example, 16K clustersize at 4K blocksize
* gives us a cluster group size of 504M. Paring the
* local alloc size down to 256 however, would give us
* only one window and around 200MB left in the
* cluster group. Instead, find the first size below
* 256 which would give us an even distribution.
*
* Larger cluster group sizes actually work out pretty
* well when pared to 256, so we don't have to do this
* for any group that fits more than two
* OCFS2_LA_MAX_DEFAULT_MB windows.
*/
if (gd_mb > (2 * OCFS2_LA_MAX_DEFAULT_MB))
la_mb = 256;
else {
unsigned int gd_mult = gd_mb;
while (gd_mult > 256)
gd_mult = gd_mult >> 1;
la_mb = gd_mult;
}
}
megs_per_slot = osb->osb_clusters_at_boot / osb->max_slots;
megs_per_slot = ocfs2_clusters_to_megabytes(osb->sb, megs_per_slot);
/* Too many nodes, too few disk clusters. */
if (megs_per_slot < la_mb)
la_mb = megs_per_slot;
/* We can't store more bits than we can in a block. */
la_max_mb = ocfs2_clusters_to_megabytes(osb->sb,
ocfs2_local_alloc_size(sb) * 8);
if (la_mb > la_max_mb)
la_mb = la_max_mb;
return la_mb;
}
unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
{
unsigned int la_mb;
unsigned int gd_mb;
unsigned int la_max_mb;
unsigned int megs_per_slot;
struct super_block *sb = osb->sb;
gd_mb = ocfs2_clusters_to_megabytes(osb->sb,
8 * ocfs2_group_bitmap_size(sb, 0, osb->s_feature_incompat));
/*
*/
if ((sb->s_blocksize == 512 && osb->s_clustersize <= 8192)
|| (sb->s_blocksize == 1024 && osb->s_clustersize == 4096))
return OCFS2_LA_OLD_DEFAULT;
/*
*/
gd_mb -= 16;
gd_mb &= 0xFFFFFFFB;
la_mb = gd_mb;
/*
*/
if (la_mb > OCFS2_LA_MAX_DEFAULT_MB) {
/*
*/
if (gd_mb > (2 * OCFS2_LA_MAX_DEFAULT_MB))
la_mb = 256;
else {
unsigned int gd_mult = gd_mb;
while (gd_mult > 256)
gd_mult = gd_mult >> 1;
la_mb = gd_mult;
}
}
megs_per_slot = osb->osb_clusters_at_boot / osb->max_slots;
megs_per_slot = ocfs2_clusters_to_megabytes(osb->sb, megs_per_slot);
/* */
if (megs_per_slot < la_mb)
la_mb = megs_per_slot;
/* */
la_max_mb = ocfs2_clusters_to_megabytes(osb->sb,
ocfs2_local_alloc_size(sb) * 8);
if (la_mb > la_max_mb)
la_mb = la_max_mb;
return la_mb;
}
