fs/nilfs2/alloc.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Persistent object (dat entry/disk inode) allocator/deallocator
   4  *
   5  * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   6  *
   7  * Originally written by Koji Sato.
   8  * Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
   9  */
  10
  11 #ifndef _NILFS_ALLOC_H
  12 #define _NILFS_ALLOC_H
  13
  14 #include <linux/types.h>
  15 #include <linux/buffer_head.h>
  16 #include <linux/fs.h>
  17
  18 /**
  19  * nilfs_palloc_entries_per_group - get the number of entries per group
  20  * @inode: inode of metadata file using this allocator
  21  *
  22  * The number of entries per group is defined by the number of bits
  23  * that a bitmap block can maintain.
  24  */
  25 static inline unsigned long
  26 nilfs_palloc_entries_per_group(const struct inode *inode)
  27 {
  28         return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
  29 }
  30
  31 int nilfs_palloc_init_blockgroup(struct inode *, unsigned int);
  32 int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
  33                                  struct buffer_head **);
  34 size_t nilfs_palloc_entry_offset(const struct inode *inode, __u64 nr,
  35                                  const struct buffer_head *bh);
  36
  37 int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);
  38
  39 /**
  40  * struct nilfs_palloc_req - persistent allocator request and reply
  41  * @pr_entry_nr: entry number (vblocknr or inode number)
  42  * @pr_desc_bh: buffer head of the buffer containing block group descriptors
  43  * @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
  44  * @pr_entry_bh: buffer head of the buffer containing translation entries
  45  */
  46 struct nilfs_palloc_req {
  47         __u64 pr_entry_nr;
  48         struct buffer_head *pr_desc_bh;
  49         struct buffer_head *pr_bitmap_bh;
  50         struct buffer_head *pr_entry_bh;
  51 };
  52
  53 int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
  54                                      struct nilfs_palloc_req *req, bool wrap);
  55 void nilfs_palloc_commit_alloc_entry(struct inode *,
  56                                      struct nilfs_palloc_req *);
  57 void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
  58 void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
  59 int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
  60 void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
  61 int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
  62
  63 #define nilfs_set_bit_atomic            ext2_set_bit_atomic
  64 #define nilfs_clear_bit_atomic          ext2_clear_bit_atomic
  65 #define nilfs_find_next_zero_bit        find_next_zero_bit_le
  66 #define nilfs_find_next_bit             find_next_bit_le
  67
  68 /**
  69  * struct nilfs_bh_assoc - block offset and buffer head association
  70  * @blkoff: block offset
  71  * @bh: buffer head
  72  */
  73 struct nilfs_bh_assoc {
  74         unsigned long blkoff;
  75         struct buffer_head *bh;
  76 };
  77
  78 /**
  79  * struct nilfs_palloc_cache - persistent object allocator cache
  80  * @lock: cache protecting lock
  81  * @prev_desc: blockgroup descriptors cache
  82  * @prev_bitmap: blockgroup bitmap cache
  83  * @prev_entry: translation entries cache
  84  */
  85 struct nilfs_palloc_cache {
  86         spinlock_t lock;
  87         struct nilfs_bh_assoc prev_desc;
  88         struct nilfs_bh_assoc prev_bitmap;
  89         struct nilfs_bh_assoc prev_entry;
  90 };
  91
  92 void nilfs_palloc_setup_cache(struct inode *inode,
  93                               struct nilfs_palloc_cache *cache);
  94 void nilfs_palloc_clear_cache(struct inode *inode);
  95 void nilfs_palloc_destroy_cache(struct inode *inode);
  96
  97 #endif  /* _NILFS_ALLOC_H */