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![Steven Whitehouse](/assets/img/avatar_default.png)
Since the start of GFS2, an "extra" inode has been used to store the metadata belonging to each inode. The only reason for using this inode was to have an extra address space, the other fields were unused. This means that the memory usage was rather inefficient. The reason for keeping each inode's metadata in a separate address space is that when glocks are requested on remote nodes, we need to be able to efficiently locate the data and metadata which relating to that glock (inode) in order to sync or sync and invalidate it (depending on the remotely requested lock mode). This patch adds a new type of glock, which has in addition to its normal fields, has an address space. This applies to all inode and rgrp glocks (but to no other glock types which remain as before). As a result, we no longer need to have the second inode. This results in three major improvements: 1. A saving of approx 25% of memory used in caching inodes 2. A removal of the circular dependency between inodes and glocks 3. No confusion between "normal" and "metadata" inodes in super.c Although the first of these is the more immediately apparent, the second is just as important as it now enables a number of clean ups at umount time. Those will be the subject of future patches. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
84 lines
2.5 KiB
C
84 lines
2.5 KiB
C
/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License version 2.
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*/
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#ifndef __DIO_DOT_H__
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#define __DIO_DOT_H__
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#include <linux/buffer_head.h>
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#include <linux/string.h>
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#include "incore.h"
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static inline void gfs2_buffer_clear(struct buffer_head *bh)
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{
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memset(bh->b_data, 0, bh->b_size);
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}
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static inline void gfs2_buffer_clear_tail(struct buffer_head *bh, int head)
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{
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BUG_ON(head > bh->b_size);
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memset(bh->b_data + head, 0, bh->b_size - head);
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}
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static inline void gfs2_buffer_copy_tail(struct buffer_head *to_bh,
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int to_head,
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struct buffer_head *from_bh,
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int from_head)
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{
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BUG_ON(from_head < to_head);
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memcpy(to_bh->b_data + to_head, from_bh->b_data + from_head,
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from_bh->b_size - from_head);
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memset(to_bh->b_data + to_bh->b_size + to_head - from_head,
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0, from_head - to_head);
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}
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extern const struct address_space_operations gfs2_meta_aops;
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static inline struct gfs2_sbd *gfs2_mapping2sbd(struct address_space *mapping)
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{
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struct inode *inode = mapping->host;
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if (mapping->a_ops == &gfs2_meta_aops)
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return (((struct gfs2_glock *)mapping) - 1)->gl_sbd;
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else
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return inode->i_sb->s_fs_info;
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}
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void gfs2_meta_sync(struct gfs2_glock *gl);
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struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno);
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int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno,
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int flags, struct buffer_head **bhp);
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int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh);
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struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create);
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void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
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int meta);
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void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr,
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int meta);
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void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
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int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
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int new, struct buffer_head **bhp);
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static inline int gfs2_meta_inode_buffer(struct gfs2_inode *ip,
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struct buffer_head **bhp)
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{
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return gfs2_meta_indirect_buffer(ip, 0, ip->i_no_addr, 0, bhp);
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}
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struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen);
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#define buffer_busy(bh) \
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((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned)))
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#define buffer_in_io(bh) \
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((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock)))
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#endif /* __DIO_DOT_H__ */
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