/**
* nilfs_palloc_group_is_in - judge if an entry is in a group
* @inode: inode of metadata file using this allocator
* @group: group number
* @nr: serial number of the entry (e.g. inode number)
*/
static int
nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr)
{
__u64 first, last;
first = group * nilfs_palloc_entries_per_group(inode);
last = first + nilfs_palloc_entries_per_group(inode) - 1;
return (nr >= first) && (nr <= last);
}
/**
* nilfs_palloc_init_blockgroup - initialize private variables for allocator
* @inode: inode of metadata file using this allocator
* @entry_size: size of the persistent object
*/
int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned int entry_size)
{
struct nilfs_mdt_info *mi = NILFS_MDT(inode);
mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
if (!mi->mi_bgl)
return -ENOMEM;
bgl_lock_init(mi->mi_bgl);
nilfs_mdt_set_entry_size(inode, entry_size, 0);
mi->mi_blocks_per_group =
DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
mi->mi_entries_per_block) + 1;
/*
* Number of blocks in a group including entry blocks
* and a bitmap block
*/
mi->mi_blocks_per_desc_block =
nilfs_palloc_groups_per_desc_block(inode) *
mi->mi_blocks_per_group + 1;
/*
* Number of blocks per descriptor including the
* descriptor block
*/
return 0;
}
/**
* nilfs_palloc_group - get group number and offset from an entry number
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry (e.g. inode number)
* @offset: pointer to store offset number in the group
*/
static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
unsigned long *offset)
{
__u64 group = nr;
*offset = do_div(group, nilfs_palloc_entries_per_group(inode));
return group;
}
__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
{
struct inode *dat = nilfs_bmap_get_dat(bmap);
unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
unsigned long group = bmap->b_inode->i_ino / entries_per_group;
return group * entries_per_group +
(bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
(entries_per_group / NILFS_BMAP_GROUP_DIV);
}
/**
* nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block
* @inode: inode of metadata file
* @bh: buffer head of the buffer to be initialized
* @kaddr: kernel address mapped for the page including the buffer
*/
static void nilfs_palloc_desc_block_init(struct inode *inode,
struct buffer_head *bh, void *kaddr)
{
struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
__le32 nfrees;
nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
while (n-- > 0) {
desc->pg_nfrees = nfrees;
desc++;
}
}
/**
* nilfs_palloc_count_max_entries - count max number of entries that can be
* described by descriptor blocks count
* @inode: inode of metadata file using this allocator
* @nused: current number of used entries
* @nmaxp: max number of entries [out]
*/
int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
{
unsigned long desc_blocks = 0;
u64 entries_per_desc_block, nmax;
int err;
err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
if (unlikely(err))
return err;
entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
nilfs_palloc_groups_per_desc_block(inode);
nmax = entries_per_desc_block * desc_blocks;
if (nused == nmax &&
nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
nmax += entries_per_desc_block;
if (nused > nmax)
return -ERANGE;
*nmaxp = nmax;
return 0;
}
/**
* nilfs_palloc_freev - deallocate a set of persistent objects
* @inode: inode of metadata file using this allocator
* @entry_nrs: array of entry numbers to be deallocated
* @nitems: number of entries stored in @entry_nrs
*/
int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
unsigned long group, group_offset;
__u64 group_min_nr, last_nrs[8];
const unsigned long epg = nilfs_palloc_entries_per_group(inode);
const unsigned int epb = NILFS_MDT(inode)->mi_entries_per_block;
unsigned int entry_start, end, pos;
spinlock_t *lock;
int i, j, k, ret;
u32 nfree;
for (i = 0; i < nitems; i = j) {
int change_group = false;
int nempties = 0, n = 0;
group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
if (ret < 0)
return ret;
ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
&bitmap_bh);
if (ret < 0) {
brelse(desc_bh);
return ret;
}
/* Get the first entry number of the group */
group_min_nr = (__u64)group * epg;
bitmap_kaddr = kmap(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
lock = nilfs_mdt_bgl_lock(inode, group);
j = i;
entry_start = rounddown(group_offset, epb);
do {
if (!nilfs_clear_bit_atomic(lock, group_offset,
bitmap)) {
nilfs_msg(inode->i_sb, KERN_WARNING,
"%s (ino=%lu): entry number %llu already freed",
__func__, inode->i_ino,
(unsigned long long)entry_nrs[j]);
} else {
n++;
}
j++;
if (j >= nitems || entry_nrs[j] < group_min_nr ||
entry_nrs[j] >= group_min_nr + epg) {
change_group = true;
} else {
group_offset = entry_nrs[j] - group_min_nr;
if (group_offset >= entry_start &&
group_offset < entry_start + epb) {
/* This entry is in the same block */
continue;
}
}
/* Test if the entry block is empty or not */
end = entry_start + epb;
pos = nilfs_find_next_bit(bitmap, end, entry_start);
if (pos >= end) {
last_nrs[nempties++] = entry_nrs[j - 1];
if (nempties >= ARRAY_SIZE(last_nrs))
break;
}
if (change_group)
break;
/* Go on to the next entry block */
entry_start = rounddown(group_offset, epb);
} while (true);
kunmap(bitmap_bh->b_page);
mark_buffer_dirty(bitmap_bh);
brelse(bitmap_bh);
for (k = 0; k < nempties; k++) {
ret = nilfs_palloc_delete_entry_block(inode,
last_nrs[k]);
if (ret && ret != -ENOENT)
nilfs_msg(inode->i_sb, KERN_WARNING,
"error %d deleting block that object (entry=%llu, ino=%lu) belongs to",
ret, (unsigned long long)last_nrs[k],
inode->i_ino);
}
desc_kaddr = kmap_atomic(desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(
inode, group, desc_bh, desc_kaddr);
nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);
kunmap_atomic(desc_kaddr);
mark_buffer_dirty(desc_bh);
nilfs_mdt_mark_dirty(inode);
brelse(desc_bh);
if (nfree == nilfs_palloc_entries_per_group(inode)) {
ret = nilfs_palloc_delete_bitmap_block(inode, group);
if (ret && ret != -ENOENT)
nilfs_msg(inode->i_sb, KERN_WARNING,
"error %d deleting bitmap block of group=%lu, ino=%lu",
ret, group, inode->i_ino);
}
}
return 0;
}
/**
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
*/
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
unsigned long group, maxgroup, ngroups;
unsigned long group_offset, maxgroup_offset;
unsigned long n, entries_per_group;
unsigned long i, j;
spinlock_t *lock;
int pos, ret;
ngroups = nilfs_palloc_groups_count(inode);
maxgroup = ngroups - 1;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
entries_per_group = nilfs_palloc_entries_per_group(inode);
for (i = 0; i < ngroups; i += n) {
if (group >= ngroups) {
/* wrap around */
group = 0;
maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
&maxgroup_offset) - 1;
}
ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
if (ret < 0)
return ret;
desc_kaddr = kmap(desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(
inode, group, desc_bh, desc_kaddr);
n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
maxgroup);
for (j = 0; j < n; j++, desc++, group++) {
lock = nilfs_mdt_bgl_lock(inode, group);
if (nilfs_palloc_group_desc_nfrees(desc, lock) > 0) {
ret = nilfs_palloc_get_bitmap_block(
inode, group, 1, &bitmap_bh);
if (ret < 0)
goto out_desc;
bitmap_kaddr = kmap(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
pos = nilfs_palloc_find_available_slot(
bitmap, group_offset,
entries_per_group, lock);
if (pos >= 0) {
/* found a free entry */
nilfs_palloc_group_desc_add_entries(
desc, lock, -1);
req->pr_entry_nr =
entries_per_group * group + pos;
kunmap(desc_bh->b_page);
kunmap(bitmap_bh->b_page);
req->pr_desc_bh = desc_bh;
req->pr_bitmap_bh = bitmap_bh;
return 0;
}
kunmap(bitmap_bh->b_page);
brelse(bitmap_bh);
}
group_offset = 0;
}
kunmap(desc_bh->b_page);
brelse(desc_bh);
}
/* no entries left */
return -ENOSPC;
out_desc:
kunmap(desc_bh->b_page);
brelse(desc_bh);
return ret;
}