diff options
author | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2009-04-06 19:01:29 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-07 08:31:13 -0700 |
commit | 5442680fd23abc01f29af585cc1a2f793bd74565 (patch) | |
tree | ecc3231149c4f0d422443cab2f4df60ba3a3ca03 /fs/nilfs2/alloc.c | |
parent | 5eb563f5f299a2ed488d9eb52acede45ccb14c7b (diff) | |
download | linux-5442680fd23abc01f29af585cc1a2f793bd74565.tar.gz linux-5442680fd23abc01f29af585cc1a2f793bd74565.tar.bz2 linux-5442680fd23abc01f29af585cc1a2f793bd74565.zip |
nilfs2: persistent object allocator
This adds common functions to allocate or deallocate entries with bitmaps
on a meta data file. This feature is used by the DAT and ifile.
Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/nilfs2/alloc.c')
-rw-r--r-- | fs/nilfs2/alloc.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c new file mode 100644 index 000000000000..d69e6ae59251 --- /dev/null +++ b/fs/nilfs2/alloc.c @@ -0,0 +1,504 @@ +/* + * alloc.c - NILFS dat/inode allocator + * + * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Original code was written by Koji Sato <koji@osrg.net>. + * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>, + * Amagai Yoshiji <amagai@osrg.net>. + */ + +#include <linux/types.h> +#include <linux/buffer_head.h> +#include <linux/fs.h> +#include <linux/bitops.h> +#include "mdt.h" +#include "alloc.h" + + +static inline unsigned long +nilfs_palloc_groups_per_desc_block(const struct inode *inode) +{ + return (1UL << inode->i_blkbits) / + sizeof(struct nilfs_palloc_group_desc); +} + +static inline unsigned long +nilfs_palloc_groups_count(const struct inode *inode) +{ + return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */)); +} + +int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned 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; +} + +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; +} + +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; +} + +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; +} + +static unsigned long +nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group, + const struct nilfs_palloc_group_desc *desc) +{ + unsigned long nfree; + + spin_lock(nilfs_mdt_bgl_lock(inode, group)); + nfree = le32_to_cpu(desc->pg_nfrees); + spin_unlock(nilfs_mdt_bgl_lock(inode, group)); + return nfree; +} + +static void +nilfs_palloc_group_desc_add_entries(struct inode *inode, + unsigned long group, + struct nilfs_palloc_group_desc *desc, + u32 n) +{ + spin_lock(nilfs_mdt_bgl_lock(inode, group)); + le32_add_cpu(&desc->pg_nfrees, n); + spin_unlock(nilfs_mdt_bgl_lock(inode, group)); +} + +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; +} + +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_desc_block(struct inode *inode, + unsigned long group, + int create, struct buffer_head **bhp) +{ + return nilfs_mdt_get_block(inode, + nilfs_palloc_desc_blkoff(inode, group), + create, nilfs_palloc_desc_block_init, bhp); +} + +static int nilfs_palloc_get_bitmap_block(struct inode *inode, + unsigned long group, + int create, struct buffer_head **bhp) +{ + return nilfs_mdt_get_block(inode, + nilfs_palloc_bitmap_blkoff(inode, group), + create, NULL, bhp); +} + +int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr, + int create, struct buffer_head **bhp) +{ + return nilfs_mdt_get_block(inode, nilfs_palloc_entry_blkoff(inode, nr), + create, NULL, bhp); +} + +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); +} + +static unsigned char * +nilfs_palloc_block_get_bitmap(const struct inode *inode, + const struct buffer_head *bh, void *kaddr) +{ + return (unsigned char *)(kaddr + bh_offset(bh)); +} + +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; +} + +static int nilfs_palloc_find_available_slot(struct inode *inode, + unsigned long group, + unsigned long target, + unsigned char *bitmap, + int bsize) /* size in bits */ +{ + int curr, pos, end, i; + + if (target > 0) { + end = (target + BITS_PER_LONG - 1) & ~(BITS_PER_LONG - 1); + if (end > bsize) + end = bsize; + pos = nilfs_find_next_zero_bit(bitmap, end, target); + if (pos < end && + !nilfs_set_bit_atomic( + nilfs_mdt_bgl_lock(inode, group), pos, bitmap)) + return pos; + } else + end = 0; + + for (i = 0, curr = end; + i < bsize; + i += BITS_PER_LONG, curr += BITS_PER_LONG) { + /* wrap around */ + if (curr >= bsize) + curr = 0; + while (*((unsigned long *)bitmap + curr / BITS_PER_LONG) + != ~0UL) { + end = curr + BITS_PER_LONG; + if (end > bsize) + end = bsize; + pos = nilfs_find_next_zero_bit(bitmap, end, curr); + if ((pos < end) && + !nilfs_set_bit_atomic( + nilfs_mdt_bgl_lock(inode, group), pos, + bitmap)) + return pos; + } + } + return -ENOSPC; +} + +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); +} + +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, groups_per_desc_block; + unsigned long i, j; + 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); + groups_per_desc_block = nilfs_palloc_groups_per_desc_block(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++) { + if (nilfs_palloc_group_desc_nfrees(inode, group, desc) + > 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 = nilfs_palloc_block_get_bitmap( + inode, bitmap_bh, bitmap_kaddr); + pos = nilfs_palloc_find_available_slot( + inode, group, group_offset, bitmap, + entries_per_group); + if (pos >= 0) { + /* found a free entry */ + nilfs_palloc_group_desc_add_entries( + inode, group, desc, -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; +} + +void nilfs_palloc_commit_alloc_entry(struct inode *inode, + struct nilfs_palloc_req *req) +{ + nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh); + nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh); + nilfs_mdt_mark_dirty(inode); + + brelse(req->pr_bitmap_bh); + brelse(req->pr_desc_bh); +} + +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; + + 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 = nilfs_palloc_block_get_bitmap(inode, req->pr_bitmap_bh, + bitmap_kaddr); + + if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group), + group_offset, bitmap)) + printk(KERN_WARNING "%s: entry number %llu already freed\n", + __func__, (unsigned long long)req->pr_entry_nr); + + nilfs_palloc_group_desc_add_entries(inode, group, desc, 1); + + kunmap(req->pr_bitmap_bh->b_page); + kunmap(req->pr_desc_bh->b_page); + + nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh); + nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh); + nilfs_mdt_mark_dirty(inode); + + brelse(req->pr_bitmap_bh); + brelse(req->pr_desc_bh); +} + +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; + + 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 = nilfs_palloc_block_get_bitmap(inode, req->pr_bitmap_bh, + bitmap_kaddr); + if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group), + group_offset, bitmap)) + printk(KERN_WARNING "%s: entry numer %llu already freed\n", + __func__, (unsigned long long)req->pr_entry_nr); + + nilfs_palloc_group_desc_add_entries(inode, group, desc, 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; +} + +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; +} + +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; +} + +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); +} + +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; + int i, j, n, ret; + + for (i = 0; i < nitems; i += n) { + 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; + } + desc_kaddr = kmap(desc_bh->b_page); + desc = nilfs_palloc_block_get_group_desc( + inode, group, desc_bh, desc_kaddr); + bitmap_kaddr = kmap(bitmap_bh->b_page); + bitmap = nilfs_palloc_block_get_bitmap( + inode, bitmap_bh, bitmap_kaddr); + for (j = i, n = 0; + (j < nitems) && nilfs_palloc_group_is_in(inode, group, + entry_nrs[j]); + j++, n++) { + nilfs_palloc_group(inode, entry_nrs[j], &group_offset); + if (!nilfs_clear_bit_atomic( + nilfs_mdt_bgl_lock(inode, group), + group_offset, bitmap)) { + printk(KERN_WARNING + "%s: entry number %llu already freed\n", + __func__, + (unsigned long long)entry_nrs[j]); + } + } + nilfs_palloc_group_desc_add_entries(inode, group, desc, n); + + kunmap(bitmap_bh->b_page); + kunmap(desc_bh->b_page); + + nilfs_mdt_mark_buffer_dirty(desc_bh); + nilfs_mdt_mark_buffer_dirty(bitmap_bh); + nilfs_mdt_mark_dirty(inode); + + brelse(bitmap_bh); + brelse(desc_bh); + } + return 0; +} |