f11459ad7d
This stops allocating multiple super block instances for a device. All snapshots and a current mode mount (i.e. latest tree) will be controlled with nilfs_root objects that are kept within an sb instance. nilfs_get_sb() is rewritten so that it always has a root object for the latest tree and snapshots make additional root objects. The root dentry of the latest tree is binded to sb->s_root even if it isn't attached on a directory. Root dentries of snapshots or the latest tree are binded to mnt->mnt_root on which they are mounted. With this patch, nilfs_find_sbinfo() function, nilfs->ns_supers list, and nilfs->ns_current back pointer, are deleted. In addition, init_nilfs() and load_nilfs() are simplified since they will be called once for a device, not repeatedly called for mount points. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
93 lines
2.5 KiB
C
93 lines
2.5 KiB
C
/*
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* sb.h - NILFS on-memory super block 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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#ifndef _NILFS_SB
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#define _NILFS_SB
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#include <linux/types.h>
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#include <linux/fs.h>
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/*
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* Mount options
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*/
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struct nilfs_mount_options {
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unsigned long mount_opt;
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__u64 snapshot_cno;
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};
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struct the_nilfs;
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struct nilfs_sc_info;
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/*
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* NILFS super-block data in memory
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*/
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struct nilfs_sb_info {
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/* Mount options */
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unsigned long s_mount_opt;
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uid_t s_resuid;
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gid_t s_resgid;
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unsigned long s_interval; /* construction interval */
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unsigned long s_watermark; /* threshold of data amount
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for the segment construction */
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/* Fundamental members */
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struct super_block *s_super; /* reverse pointer to super_block */
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struct the_nilfs *s_nilfs;
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/* Segment constructor */
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struct list_head s_dirty_files; /* dirty files list */
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struct nilfs_sc_info *s_sc_info; /* segment constructor info */
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spinlock_t s_inode_lock; /* Lock for the nilfs inode.
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It covers s_dirty_files list */
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/* Inode allocator */
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spinlock_t s_next_gen_lock;
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u32 s_next_generation;
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};
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static inline struct nilfs_sb_info *NILFS_SB(struct super_block *sb)
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{
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return sb->s_fs_info;
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}
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static inline struct nilfs_sc_info *NILFS_SC(struct nilfs_sb_info *sbi)
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{
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return sbi->s_sc_info;
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}
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/*
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* Bit operations for the mount option
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*/
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#define nilfs_clear_opt(sbi, opt) \
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do { (sbi)->s_mount_opt &= ~NILFS_MOUNT_##opt; } while (0)
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#define nilfs_set_opt(sbi, opt) \
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do { (sbi)->s_mount_opt |= NILFS_MOUNT_##opt; } while (0)
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#define nilfs_test_opt(sbi, opt) ((sbi)->s_mount_opt & NILFS_MOUNT_##opt)
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#define nilfs_write_opt(sbi, mask, opt) \
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do { (sbi)->s_mount_opt = \
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(((sbi)->s_mount_opt & ~NILFS_MOUNT_##mask) | \
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NILFS_MOUNT_##opt); \
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} while (0)
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#endif /* _NILFS_SB */
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