v4.19.13 snapshot.
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
new file mode 100644
index 0000000..235b959
--- /dev/null
+++ b/fs/nilfs2/alloc.c
@@ -0,0 +1,862 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * alloc.c - NILFS dat/inode allocator
+ *
+ * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
+ *
+ * Originally written by Koji Sato.
+ * Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
+ */
+
+#include <linux/types.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include "mdt.h"
+#include "alloc.h"
+
+
+/**
+ * nilfs_palloc_groups_per_desc_block - get the number of groups that a group
+ * descriptor block can maintain
+ * @inode: inode of metadata file using this allocator
+ */
+static inline unsigned long
+nilfs_palloc_groups_per_desc_block(const struct inode *inode)
+{
+ return i_blocksize(inode) /
+ sizeof(struct nilfs_palloc_group_desc);
+}
+
+/**
+ * nilfs_palloc_groups_count - get maximum number of groups
+ * @inode: inode of metadata file using this allocator
+ */
+static inline unsigned long
+nilfs_palloc_groups_count(const struct inode *inode)
+{
+ return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
+}
+
+/**
+ * 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;
+}
+
+/**
+ * nilfs_palloc_desc_blkoff - get block offset of a group descriptor block
+ * @inode: inode of metadata file using this allocator
+ * @group: group number
+ *
+ * nilfs_palloc_desc_blkoff() returns block offset of the descriptor
+ * block which contains a descriptor of the specified group.
+ */
+static unsigned long
+nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
+{
+ unsigned long desc_block =
+ group / nilfs_palloc_groups_per_desc_block(inode);
+ return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
+}
+
+/**
+ * nilfs_palloc_bitmap_blkoff - get block offset of a bitmap block
+ * @inode: inode of metadata file using this allocator
+ * @group: group number
+ *
+ * nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap
+ * block used to allocate/deallocate entries in the specified group.
+ */
+static unsigned long
+nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
+{
+ unsigned long desc_offset =
+ group % nilfs_palloc_groups_per_desc_block(inode);
+ return nilfs_palloc_desc_blkoff(inode, group) + 1 +
+ desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
+}
+
+/**
+ * nilfs_palloc_group_desc_nfrees - get the number of free entries in a group
+ * @desc: pointer to descriptor structure for the group
+ * @lock: spin lock protecting @desc
+ */
+static unsigned long
+nilfs_palloc_group_desc_nfrees(const struct nilfs_palloc_group_desc *desc,
+ spinlock_t *lock)
+{
+ unsigned long nfree;
+
+ spin_lock(lock);
+ nfree = le32_to_cpu(desc->pg_nfrees);
+ spin_unlock(lock);
+ return nfree;
+}
+
+/**
+ * nilfs_palloc_group_desc_add_entries - adjust count of free entries
+ * @desc: pointer to descriptor structure for the group
+ * @lock: spin lock protecting @desc
+ * @n: delta to be added
+ */
+static u32
+nilfs_palloc_group_desc_add_entries(struct nilfs_palloc_group_desc *desc,
+ spinlock_t *lock, u32 n)
+{
+ u32 nfree;
+
+ spin_lock(lock);
+ le32_add_cpu(&desc->pg_nfrees, n);
+ nfree = le32_to_cpu(desc->pg_nfrees);
+ spin_unlock(lock);
+ return nfree;
+}
+
+/**
+ * nilfs_palloc_entry_blkoff - get block offset of an entry block
+ * @inode: inode of metadata file using this allocator
+ * @nr: serial number of the entry (e.g. inode number)
+ */
+static unsigned long
+nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
+{
+ unsigned long group, group_offset;
+
+ group = nilfs_palloc_group(inode, nr, &group_offset);
+
+ return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
+ group_offset / NILFS_MDT(inode)->mi_entries_per_block;
+}
+
+/**
+ * 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++;
+ }
+}
+
+static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
+ int create,
+ void (*init_block)(struct inode *,
+ struct buffer_head *,
+ void *),
+ struct buffer_head **bhp,
+ struct nilfs_bh_assoc *prev,
+ spinlock_t *lock)
+{
+ int ret;
+
+ spin_lock(lock);
+ if (prev->bh && blkoff == prev->blkoff) {
+ get_bh(prev->bh);
+ *bhp = prev->bh;
+ spin_unlock(lock);
+ return 0;
+ }
+ spin_unlock(lock);
+
+ ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
+ if (!ret) {
+ spin_lock(lock);
+ /*
+ * The following code must be safe for change of the
+ * cache contents during the get block call.
+ */
+ brelse(prev->bh);
+ get_bh(*bhp);
+ prev->bh = *bhp;
+ prev->blkoff = blkoff;
+ spin_unlock(lock);
+ }
+ return ret;
+}
+
+/**
+ * nilfs_palloc_delete_block - delete a block on the persistent allocator file
+ * @inode: inode of metadata file using this allocator
+ * @blkoff: block offset
+ * @prev: nilfs_bh_assoc struct of the last used buffer
+ * @lock: spin lock protecting @prev
+ */
+static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
+ struct nilfs_bh_assoc *prev,
+ spinlock_t *lock)
+{
+ spin_lock(lock);
+ if (prev->bh && blkoff == prev->blkoff) {
+ brelse(prev->bh);
+ prev->bh = NULL;
+ }
+ spin_unlock(lock);
+ return nilfs_mdt_delete_block(inode, blkoff);
+}
+
+/**
+ * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block
+ * @inode: inode of metadata file using this allocator
+ * @group: group number
+ * @create: create flag
+ * @bhp: pointer to store the resultant buffer head
+ */
+static int nilfs_palloc_get_desc_block(struct inode *inode,
+ unsigned long group,
+ int create, struct buffer_head **bhp)
+{
+ struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
+
+ return nilfs_palloc_get_block(inode,
+ nilfs_palloc_desc_blkoff(inode, group),
+ create, nilfs_palloc_desc_block_init,
+ bhp, &cache->prev_desc, &cache->lock);
+}
+
+/**
+ * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
+ * @inode: inode of metadata file using this allocator
+ * @group: group number
+ * @create: create flag
+ * @bhp: pointer to store the resultant buffer head
+ */
+static int nilfs_palloc_get_bitmap_block(struct inode *inode,
+ unsigned long group,
+ int create, struct buffer_head **bhp)
+{
+ struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
+
+ return nilfs_palloc_get_block(inode,
+ nilfs_palloc_bitmap_blkoff(inode, group),
+ create, NULL, bhp,
+ &cache->prev_bitmap, &cache->lock);
+}
+
+/**
+ * nilfs_palloc_delete_bitmap_block - delete a bitmap block
+ * @inode: inode of metadata file using this allocator
+ * @group: group number
+ */
+static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
+ unsigned long group)
+{
+ struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
+
+ return nilfs_palloc_delete_block(inode,
+ nilfs_palloc_bitmap_blkoff(inode,
+ group),
+ &cache->prev_bitmap, &cache->lock);
+}
+
+/**
+ * nilfs_palloc_get_entry_block - get buffer head of an entry block
+ * @inode: inode of metadata file using this allocator
+ * @nr: serial number of the entry (e.g. inode number)
+ * @create: create flag
+ * @bhp: pointer to store the resultant buffer head
+ */
+int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
+ int create, struct buffer_head **bhp)
+{
+ struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
+
+ return nilfs_palloc_get_block(inode,
+ nilfs_palloc_entry_blkoff(inode, nr),
+ create, NULL, bhp,
+ &cache->prev_entry, &cache->lock);
+}
+
+/**
+ * nilfs_palloc_delete_entry_block - delete an entry block
+ * @inode: inode of metadata file using this allocator
+ * @nr: serial number of the entry
+ */
+static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
+{
+ struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
+
+ return nilfs_palloc_delete_block(inode,
+ nilfs_palloc_entry_blkoff(inode, nr),
+ &cache->prev_entry, &cache->lock);
+}
+
+/**
+ * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
+ * @inode: inode of metadata file using this allocator
+ * @group: group number
+ * @bh: buffer head of the buffer storing the group descriptor block
+ * @kaddr: kernel address mapped for the page including the buffer
+ */
+static struct nilfs_palloc_group_desc *
+nilfs_palloc_block_get_group_desc(const struct inode *inode,
+ unsigned long group,
+ const struct buffer_head *bh, void *kaddr)
+{
+ return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
+ group % nilfs_palloc_groups_per_desc_block(inode);
+}
+
+/**
+ * nilfs_palloc_block_get_entry - get kernel address of an entry
+ * @inode: inode of metadata file using this allocator
+ * @nr: serial number of the entry (e.g. inode number)
+ * @bh: buffer head of the buffer storing the entry block
+ * @kaddr: kernel address mapped for the page including the buffer
+ */
+void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
+ const struct buffer_head *bh, void *kaddr)
+{
+ unsigned long entry_offset, group_offset;
+
+ nilfs_palloc_group(inode, nr, &group_offset);
+ entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
+
+ return kaddr + bh_offset(bh) +
+ entry_offset * NILFS_MDT(inode)->mi_entry_size;
+}
+
+/**
+ * nilfs_palloc_find_available_slot - find available slot in a group
+ * @bitmap: bitmap of the group
+ * @target: offset number of an entry in the group (start point)
+ * @bsize: size in bits
+ * @lock: spin lock protecting @bitmap
+ */
+static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
+ unsigned long target,
+ unsigned int bsize,
+ spinlock_t *lock)
+{
+ int pos, end = bsize;
+
+ if (likely(target < bsize)) {
+ pos = target;
+ do {
+ pos = nilfs_find_next_zero_bit(bitmap, end, pos);
+ if (pos >= end)
+ break;
+ if (!nilfs_set_bit_atomic(lock, pos, bitmap))
+ return pos;
+ } while (++pos < end);
+
+ end = target;
+ }
+
+ /* wrap around */
+ for (pos = 0; pos < end; pos++) {
+ pos = nilfs_find_next_zero_bit(bitmap, end, pos);
+ if (pos >= end)
+ break;
+ if (!nilfs_set_bit_atomic(lock, pos, bitmap))
+ return pos;
+ }
+
+ return -ENOSPC;
+}
+
+/**
+ * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
+ * in a group descriptor block
+ * @inode: inode of metadata file using this allocator
+ * @curr: current group number
+ * @max: maximum number of groups
+ */
+static unsigned long
+nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
+ unsigned long curr, unsigned long max)
+{
+ return min_t(unsigned long,
+ nilfs_palloc_groups_per_desc_block(inode) -
+ curr % nilfs_palloc_groups_per_desc_block(inode),
+ max - curr + 1);
+}
+
+/**
+ * nilfs_palloc_count_desc_blocks - count descriptor blocks number
+ * @inode: inode of metadata file using this allocator
+ * @desc_blocks: descriptor blocks number [out]
+ */
+static int nilfs_palloc_count_desc_blocks(struct inode *inode,
+ unsigned long *desc_blocks)
+{
+ __u64 blknum;
+ int ret;
+
+ ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
+ if (likely(!ret))
+ *desc_blocks = DIV_ROUND_UP(
+ (unsigned long)blknum,
+ NILFS_MDT(inode)->mi_blocks_per_desc_block);
+ return ret;
+}
+
+/**
+ * nilfs_palloc_mdt_file_can_grow - check potential opportunity for
+ * MDT file growing
+ * @inode: inode of metadata file using this allocator
+ * @desc_blocks: known current descriptor blocks count
+ */
+static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
+ unsigned long desc_blocks)
+{
+ return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
+ nilfs_palloc_groups_count(inode);
+}
+
+/**
+ * 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_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;
+}
+
+/**
+ * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
+ * @inode: inode of metadata file using this allocator
+ * @req: nilfs_palloc_req structure exchanged for the allocation
+ */
+void nilfs_palloc_commit_alloc_entry(struct inode *inode,
+ struct nilfs_palloc_req *req)
+{
+ mark_buffer_dirty(req->pr_bitmap_bh);
+ mark_buffer_dirty(req->pr_desc_bh);
+ nilfs_mdt_mark_dirty(inode);
+
+ brelse(req->pr_bitmap_bh);
+ brelse(req->pr_desc_bh);
+}
+
+/**
+ * nilfs_palloc_commit_free_entry - finish deallocating a persistent object
+ * @inode: inode of metadata file using this allocator
+ * @req: nilfs_palloc_req structure exchanged for the removal
+ */
+void nilfs_palloc_commit_free_entry(struct inode *inode,
+ struct nilfs_palloc_req *req)
+{
+ struct nilfs_palloc_group_desc *desc;
+ unsigned long group, group_offset;
+ unsigned char *bitmap;
+ void *desc_kaddr, *bitmap_kaddr;
+ spinlock_t *lock;
+
+ group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
+ desc_kaddr = kmap(req->pr_desc_bh->b_page);
+ desc = nilfs_palloc_block_get_group_desc(inode, group,
+ req->pr_desc_bh, desc_kaddr);
+ bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
+ bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
+ lock = nilfs_mdt_bgl_lock(inode, group);
+
+ 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)req->pr_entry_nr);
+ else
+ nilfs_palloc_group_desc_add_entries(desc, lock, 1);
+
+ kunmap(req->pr_bitmap_bh->b_page);
+ kunmap(req->pr_desc_bh->b_page);
+
+ mark_buffer_dirty(req->pr_desc_bh);
+ mark_buffer_dirty(req->pr_bitmap_bh);
+ nilfs_mdt_mark_dirty(inode);
+
+ brelse(req->pr_bitmap_bh);
+ brelse(req->pr_desc_bh);
+}
+
+/**
+ * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
+ * @inode: inode of metadata file using this allocator
+ * @req: nilfs_palloc_req structure exchanged for the allocation
+ */
+void nilfs_palloc_abort_alloc_entry(struct inode *inode,
+ struct nilfs_palloc_req *req)
+{
+ struct nilfs_palloc_group_desc *desc;
+ void *desc_kaddr, *bitmap_kaddr;
+ unsigned char *bitmap;
+ unsigned long group, group_offset;
+ spinlock_t *lock;
+
+ group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
+ desc_kaddr = kmap(req->pr_desc_bh->b_page);
+ desc = nilfs_palloc_block_get_group_desc(inode, group,
+ req->pr_desc_bh, desc_kaddr);
+ bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
+ bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
+ lock = nilfs_mdt_bgl_lock(inode, group);
+
+ 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)req->pr_entry_nr);
+ else
+ nilfs_palloc_group_desc_add_entries(desc, lock, 1);
+
+ kunmap(req->pr_bitmap_bh->b_page);
+ kunmap(req->pr_desc_bh->b_page);
+
+ brelse(req->pr_bitmap_bh);
+ brelse(req->pr_desc_bh);
+
+ req->pr_entry_nr = 0;
+ req->pr_bitmap_bh = NULL;
+ req->pr_desc_bh = NULL;
+}
+
+/**
+ * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
+ * @inode: inode of metadata file using this allocator
+ * @req: nilfs_palloc_req structure exchanged for the removal
+ */
+int nilfs_palloc_prepare_free_entry(struct inode *inode,
+ struct nilfs_palloc_req *req)
+{
+ struct buffer_head *desc_bh, *bitmap_bh;
+ unsigned long group, group_offset;
+ int ret;
+
+ group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
+ ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
+ if (ret < 0)
+ return ret;
+ ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
+ if (ret < 0) {
+ brelse(desc_bh);
+ return ret;
+ }
+
+ req->pr_desc_bh = desc_bh;
+ req->pr_bitmap_bh = bitmap_bh;
+ return 0;
+}
+
+/**
+ * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
+ * @inode: inode of metadata file using this allocator
+ * @req: nilfs_palloc_req structure exchanged for the removal
+ */
+void nilfs_palloc_abort_free_entry(struct inode *inode,
+ struct nilfs_palloc_req *req)
+{
+ brelse(req->pr_bitmap_bh);
+ brelse(req->pr_desc_bh);
+
+ req->pr_entry_nr = 0;
+ req->pr_bitmap_bh = NULL;
+ req->pr_desc_bh = NULL;
+}
+
+/**
+ * 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;
+}
+
+void nilfs_palloc_setup_cache(struct inode *inode,
+ struct nilfs_palloc_cache *cache)
+{
+ NILFS_MDT(inode)->mi_palloc_cache = cache;
+ spin_lock_init(&cache->lock);
+}
+
+void nilfs_palloc_clear_cache(struct inode *inode)
+{
+ struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
+
+ spin_lock(&cache->lock);
+ brelse(cache->prev_desc.bh);
+ brelse(cache->prev_bitmap.bh);
+ brelse(cache->prev_entry.bh);
+ cache->prev_desc.bh = NULL;
+ cache->prev_bitmap.bh = NULL;
+ cache->prev_entry.bh = NULL;
+ spin_unlock(&cache->lock);
+}
+
+void nilfs_palloc_destroy_cache(struct inode *inode)
+{
+ nilfs_palloc_clear_cache(inode);
+ NILFS_MDT(inode)->mi_palloc_cache = NULL;
+}