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nilfs2: operations for the_nilfs core object
This adds functions on the_nilfs object, which keeps shared resources and states among a read/write mount and snapshots mounts going individually. the_nilfs is allocated per block device; it is created when user first mount a snapshot or a read/write mount on the device, then it is reused for successive mounts. It will be freed when all mount instances on the device are detached. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ryusuke Konishi
Linus Torvalds
parent
d25006523d
commit
8a9d2191e9
1 changed files with 524 additions and 0 deletions
524
fs/nilfs2/the_nilfs.c
Normal file
524
fs/nilfs2/the_nilfs.c
Normal file
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@ -0,0 +1,524 @@
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/*
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* the_nilfs.c - the_nilfs shared structure.
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*
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Written by Ryusuke Konishi <ryusuke@osrg.net>
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*
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*/
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#include <linux/buffer_head.h>
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/backing-dev.h>
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#include "nilfs.h"
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#include "segment.h"
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#include "alloc.h"
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#include "cpfile.h"
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#include "sufile.h"
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#include "dat.h"
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#include "seglist.h"
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#include "segbuf.h"
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void nilfs_set_last_segment(struct the_nilfs *nilfs,
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sector_t start_blocknr, u64 seq, __u64 cno)
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{
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spin_lock(&nilfs->ns_last_segment_lock);
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nilfs->ns_last_pseg = start_blocknr;
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nilfs->ns_last_seq = seq;
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nilfs->ns_last_cno = cno;
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spin_unlock(&nilfs->ns_last_segment_lock);
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}
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/**
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* alloc_nilfs - allocate the_nilfs structure
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* @bdev: block device to which the_nilfs is related
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*
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* alloc_nilfs() allocates memory for the_nilfs and
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* initializes its reference count and locks.
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*
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* Return Value: On success, pointer to the_nilfs is returned.
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* On error, NULL is returned.
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*/
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struct the_nilfs *alloc_nilfs(struct block_device *bdev)
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{
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struct the_nilfs *nilfs;
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nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
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if (!nilfs)
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return NULL;
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nilfs->ns_bdev = bdev;
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atomic_set(&nilfs->ns_count, 1);
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atomic_set(&nilfs->ns_writer_refcount, -1);
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atomic_set(&nilfs->ns_ndirtyblks, 0);
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init_rwsem(&nilfs->ns_sem);
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mutex_init(&nilfs->ns_writer_mutex);
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INIT_LIST_HEAD(&nilfs->ns_supers);
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spin_lock_init(&nilfs->ns_last_segment_lock);
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nilfs->ns_gc_inodes_h = NULL;
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INIT_LIST_HEAD(&nilfs->ns_used_segments);
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init_rwsem(&nilfs->ns_segctor_sem);
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init_waitqueue_head(&nilfs->ns_cleanerd_wq);
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return nilfs;
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}
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/**
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* put_nilfs - release a reference to the_nilfs
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* @nilfs: the_nilfs structure to be released
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*
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* put_nilfs() decrements a reference counter of the_nilfs.
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* If the reference count reaches zero, the_nilfs is freed.
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*/
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void put_nilfs(struct the_nilfs *nilfs)
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{
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if (!atomic_dec_and_test(&nilfs->ns_count))
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return;
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/*
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* Increment of ns_count never occur below because the caller
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* of get_nilfs() holds at least one reference to the_nilfs.
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* Thus its exclusion control is not required here.
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*/
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might_sleep();
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if (nilfs_loaded(nilfs)) {
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nilfs_dispose_used_segments(nilfs);
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nilfs_mdt_clear(nilfs->ns_sufile);
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nilfs_mdt_destroy(nilfs->ns_sufile);
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nilfs_mdt_clear(nilfs->ns_cpfile);
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nilfs_mdt_destroy(nilfs->ns_cpfile);
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nilfs_mdt_clear(nilfs->ns_dat);
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nilfs_mdt_destroy(nilfs->ns_dat);
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/* XXX: how and when to clear nilfs->ns_gc_dat? */
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nilfs_mdt_destroy(nilfs->ns_gc_dat);
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}
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if (nilfs_init(nilfs)) {
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nilfs_destroy_gccache(nilfs);
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brelse(nilfs->ns_sbh);
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}
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kfree(nilfs);
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}
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static int nilfs_load_super_root(struct the_nilfs *nilfs,
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struct nilfs_sb_info *sbi, sector_t sr_block)
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{
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struct buffer_head *bh_sr;
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struct nilfs_super_root *raw_sr;
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unsigned dat_entry_size, segment_usage_size, checkpoint_size;
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unsigned inode_size;
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int err;
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err = nilfs_read_super_root_block(sbi->s_super, sr_block, &bh_sr, 1);
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if (unlikely(err))
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return err;
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down_read(&nilfs->ns_sem);
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dat_entry_size = le16_to_cpu(nilfs->ns_sbp->s_dat_entry_size);
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checkpoint_size = le16_to_cpu(nilfs->ns_sbp->s_checkpoint_size);
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segment_usage_size = le16_to_cpu(nilfs->ns_sbp->s_segment_usage_size);
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up_read(&nilfs->ns_sem);
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inode_size = nilfs->ns_inode_size;
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err = -ENOMEM;
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nilfs->ns_dat = nilfs_mdt_new(
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nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
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if (unlikely(!nilfs->ns_dat))
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goto failed;
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nilfs->ns_gc_dat = nilfs_mdt_new(
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nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
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if (unlikely(!nilfs->ns_gc_dat))
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goto failed_dat;
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nilfs->ns_cpfile = nilfs_mdt_new(
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nilfs, NULL, NILFS_CPFILE_INO, NILFS_CPFILE_GFP);
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if (unlikely(!nilfs->ns_cpfile))
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goto failed_gc_dat;
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nilfs->ns_sufile = nilfs_mdt_new(
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nilfs, NULL, NILFS_SUFILE_INO, NILFS_SUFILE_GFP);
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if (unlikely(!nilfs->ns_sufile))
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goto failed_cpfile;
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err = nilfs_palloc_init_blockgroup(nilfs->ns_dat, dat_entry_size);
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if (unlikely(err))
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goto failed_sufile;
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err = nilfs_palloc_init_blockgroup(nilfs->ns_gc_dat, dat_entry_size);
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if (unlikely(err))
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goto failed_sufile;
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nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);
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nilfs_mdt_set_entry_size(nilfs->ns_cpfile, checkpoint_size,
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sizeof(struct nilfs_cpfile_header));
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nilfs_mdt_set_entry_size(nilfs->ns_sufile, segment_usage_size,
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sizeof(struct nilfs_sufile_header));
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err = nilfs_mdt_read_inode_direct(
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nilfs->ns_dat, bh_sr, NILFS_SR_DAT_OFFSET(inode_size));
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if (unlikely(err))
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goto failed_sufile;
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err = nilfs_mdt_read_inode_direct(
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nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(inode_size));
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if (unlikely(err))
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goto failed_sufile;
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err = nilfs_mdt_read_inode_direct(
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nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(inode_size));
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if (unlikely(err))
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goto failed_sufile;
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raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
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nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
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failed:
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brelse(bh_sr);
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return err;
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failed_sufile:
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nilfs_mdt_destroy(nilfs->ns_sufile);
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failed_cpfile:
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nilfs_mdt_destroy(nilfs->ns_cpfile);
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failed_gc_dat:
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nilfs_mdt_destroy(nilfs->ns_gc_dat);
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failed_dat:
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nilfs_mdt_destroy(nilfs->ns_dat);
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goto failed;
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}
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static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
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{
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memset(ri, 0, sizeof(*ri));
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INIT_LIST_HEAD(&ri->ri_used_segments);
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}
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static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
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{
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nilfs_dispose_segment_list(&ri->ri_used_segments);
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}
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/**
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* load_nilfs - load and recover the nilfs
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* @nilfs: the_nilfs structure to be released
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* @sbi: nilfs_sb_info used to recover past segment
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*
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* load_nilfs() searches and load the latest super root,
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* attaches the last segment, and does recovery if needed.
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* The caller must call this exclusively for simultaneous mounts.
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*/
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int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
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{
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struct nilfs_recovery_info ri;
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unsigned int s_flags = sbi->s_super->s_flags;
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int really_read_only = bdev_read_only(nilfs->ns_bdev);
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unsigned valid_fs;
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int err = 0;
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nilfs_init_recovery_info(&ri);
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down_write(&nilfs->ns_sem);
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valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
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up_write(&nilfs->ns_sem);
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if (!valid_fs && (s_flags & MS_RDONLY)) {
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printk(KERN_INFO "NILFS: INFO: recovery "
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"required for readonly filesystem.\n");
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if (really_read_only) {
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printk(KERN_ERR "NILFS: write access "
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"unavailable, cannot proceed.\n");
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err = -EROFS;
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goto failed;
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}
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printk(KERN_INFO "NILFS: write access will "
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"be enabled during recovery.\n");
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sbi->s_super->s_flags &= ~MS_RDONLY;
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}
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err = nilfs_search_super_root(nilfs, sbi, &ri);
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if (unlikely(err)) {
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printk(KERN_ERR "NILFS: error searching super root.\n");
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goto failed;
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}
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err = nilfs_load_super_root(nilfs, sbi, ri.ri_super_root);
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if (unlikely(err)) {
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printk(KERN_ERR "NILFS: error loading super root.\n");
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goto failed;
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}
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if (!valid_fs) {
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err = nilfs_recover_logical_segments(nilfs, sbi, &ri);
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if (unlikely(err)) {
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nilfs_mdt_destroy(nilfs->ns_cpfile);
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nilfs_mdt_destroy(nilfs->ns_sufile);
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nilfs_mdt_destroy(nilfs->ns_dat);
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goto failed;
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}
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if (ri.ri_need_recovery == NILFS_RECOVERY_SR_UPDATED) {
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down_write(&nilfs->ns_sem);
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nilfs_update_last_segment(sbi, 0);
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up_write(&nilfs->ns_sem);
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}
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}
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set_nilfs_loaded(nilfs);
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failed:
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nilfs_clear_recovery_info(&ri);
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sbi->s_super->s_flags = s_flags;
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return err;
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}
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static unsigned long long nilfs_max_size(unsigned int blkbits)
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{
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unsigned int max_bits;
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unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
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max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
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if (max_bits < 64)
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res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
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return res;
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}
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static int
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nilfs_store_disk_layout(struct the_nilfs *nilfs, struct super_block *sb,
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struct nilfs_super_block *sbp)
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{
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if (le32_to_cpu(sbp->s_rev_level) != NILFS_CURRENT_REV) {
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printk(KERN_ERR "NILFS: revision mismatch "
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"(superblock rev.=%d.%d, current rev.=%d.%d). "
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"Please check the version of mkfs.nilfs.\n",
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le32_to_cpu(sbp->s_rev_level),
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le16_to_cpu(sbp->s_minor_rev_level),
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NILFS_CURRENT_REV, NILFS_MINOR_REV);
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return -EINVAL;
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}
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nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
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nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
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nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
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if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
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printk(KERN_ERR "NILFS: too short segment. \n");
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return -EINVAL;
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}
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nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
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nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments);
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nilfs->ns_r_segments_percentage =
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le32_to_cpu(sbp->s_r_segments_percentage);
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nilfs->ns_nrsvsegs =
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max_t(unsigned long, NILFS_MIN_NRSVSEGS,
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DIV_ROUND_UP(nilfs->ns_nsegments *
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nilfs->ns_r_segments_percentage, 100));
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nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
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return 0;
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}
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/**
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* init_nilfs - initialize a NILFS instance.
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* @nilfs: the_nilfs structure
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* @sbi: nilfs_sb_info
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* @sb: super block
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* @data: mount options
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*
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* init_nilfs() performs common initialization per block device (e.g.
|
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* reading the super block, getting disk layout information, initializing
|
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* shared fields in the_nilfs). It takes on some portion of the jobs
|
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* typically done by a fill_super() routine. This division arises from
|
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* the nature that multiple NILFS instances may be simultaneously
|
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* mounted on a device.
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* For multiple mounts on the same device, only the first mount
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* invokes these tasks.
|
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*
|
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* Return Value: On success, 0 is returned. On error, a negative error
|
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* code is returned.
|
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*/
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int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data)
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{
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struct super_block *sb = sbi->s_super;
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struct buffer_head *sbh;
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struct nilfs_super_block *sbp;
|
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struct backing_dev_info *bdi;
|
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int blocksize;
|
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int err = 0;
|
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|
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down_write(&nilfs->ns_sem);
|
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if (nilfs_init(nilfs)) {
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/* Load values from existing the_nilfs */
|
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sbp = nilfs->ns_sbp;
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err = nilfs_store_magic_and_option(sb, sbp, data);
|
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if (err)
|
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goto out;
|
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|
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blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
|
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if (sb->s_blocksize != blocksize &&
|
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!sb_set_blocksize(sb, blocksize)) {
|
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printk(KERN_ERR "NILFS: blocksize %d unfit to device\n",
|
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blocksize);
|
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err = -EINVAL;
|
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}
|
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sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
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goto out;
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}
|
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|
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sbp = nilfs_load_super_block(sb, &sbh);
|
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if (!sbp) {
|
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err = -EINVAL;
|
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goto out;
|
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}
|
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err = nilfs_store_magic_and_option(sb, sbp, data);
|
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if (err)
|
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goto failed_sbh;
|
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|
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blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
|
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if (sb->s_blocksize != blocksize) {
|
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sbp = nilfs_reload_super_block(sb, &sbh, blocksize);
|
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if (!sbp) {
|
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err = -EINVAL;
|
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goto out;
|
||||
/* not failed_sbh; sbh is released automatically
|
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when reloading fails. */
|
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}
|
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}
|
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nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
|
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|
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err = nilfs_store_disk_layout(nilfs, sb, sbp);
|
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if (err)
|
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goto failed_sbh;
|
||||
|
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sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
|
||||
|
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nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
|
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nilfs->ns_sbh = sbh;
|
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nilfs->ns_sbp = sbp;
|
||||
|
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bdi = nilfs->ns_bdev->bd_inode_backing_dev_info;
|
||||
if (!bdi)
|
||||
bdi = nilfs->ns_bdev->bd_inode->i_mapping->backing_dev_info;
|
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nilfs->ns_bdi = bdi ? : &default_backing_dev_info;
|
||||
|
||||
/* Finding last segment */
|
||||
nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
|
||||
nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
|
||||
nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
|
||||
|
||||
nilfs->ns_seg_seq = nilfs->ns_last_seq;
|
||||
nilfs->ns_segnum =
|
||||
nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
|
||||
nilfs->ns_cno = nilfs->ns_last_cno + 1;
|
||||
if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
|
||||
printk(KERN_ERR "NILFS invalid last segment number.\n");
|
||||
err = -EINVAL;
|
||||
goto failed_sbh;
|
||||
}
|
||||
/* Dummy values */
|
||||
nilfs->ns_free_segments_count =
|
||||
nilfs->ns_nsegments - (nilfs->ns_segnum + 1);
|
||||
|
||||
/* Initialize gcinode cache */
|
||||
err = nilfs_init_gccache(nilfs);
|
||||
if (err)
|
||||
goto failed_sbh;
|
||||
|
||||
set_nilfs_init(nilfs);
|
||||
err = 0;
|
||||
out:
|
||||
up_write(&nilfs->ns_sem);
|
||||
return err;
|
||||
|
||||
failed_sbh:
|
||||
brelse(sbh);
|
||||
goto out;
|
||||
}
|
||||
|
||||
int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
|
||||
{
|
||||
struct inode *dat = nilfs_dat_inode(nilfs);
|
||||
unsigned long ncleansegs;
|
||||
int err;
|
||||
|
||||
down_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
|
||||
err = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile, &ncleansegs);
|
||||
up_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
|
||||
if (likely(!err))
|
||||
*nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
|
||||
return err;
|
||||
}
|
||||
|
||||
void nilfs_dispose_used_segments(struct the_nilfs *nilfs)
|
||||
{
|
||||
struct nilfs_segment_entry *ent, *n;
|
||||
|
||||
/* nilfs->sem must be locked by the caller. */
|
||||
if (!nilfs_loaded(nilfs))
|
||||
return;
|
||||
|
||||
list_for_each_entry_safe(ent, n, &nilfs->ns_used_segments, list) {
|
||||
list_del_init(&ent->list);
|
||||
nilfs_segment_usage_clear_volatile_active(ent->raw_su);
|
||||
nilfs_close_segment_entry(ent, nilfs->ns_sufile);
|
||||
nilfs_free_segment_entry(ent);
|
||||
}
|
||||
}
|
||||
|
||||
int nilfs_near_disk_full(struct the_nilfs *nilfs)
|
||||
{
|
||||
struct inode *sufile = nilfs->ns_sufile;
|
||||
unsigned long ncleansegs, nincsegs;
|
||||
int ret;
|
||||
|
||||
ret = nilfs_sufile_get_ncleansegs(sufile, &ncleansegs);
|
||||
if (likely(!ret)) {
|
||||
nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
|
||||
nilfs->ns_blocks_per_segment + 1;
|
||||
if (ncleansegs <= nilfs->ns_nrsvsegs + nincsegs)
|
||||
ret++;
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
|
||||
int snapshot_mount)
|
||||
{
|
||||
struct nilfs_sb_info *sbi;
|
||||
int ret = 0;
|
||||
|
||||
down_read(&nilfs->ns_sem);
|
||||
if (cno == 0 || cno > nilfs->ns_cno)
|
||||
goto out_unlock;
|
||||
|
||||
list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
|
||||
if (sbi->s_snapshot_cno == cno &&
|
||||
(!snapshot_mount || nilfs_test_opt(sbi, SNAPSHOT))) {
|
||||
/* exclude read-only mounts */
|
||||
ret++;
|
||||
break;
|
||||
}
|
||||
}
|
||||
/* for protecting recent checkpoints */
|
||||
if (cno >= nilfs_last_cno(nilfs))
|
||||
ret++;
|
||||
|
||||
out_unlock:
|
||||
up_read(&nilfs->ns_sem);
|
||||
return ret;
|
||||
}
|
||||
Loading…
Reference in a new issue