forked from luck/tmp_suning_uos_patched
7276b3b0c7
Fix a bug in the directory reading code, where we might have dereferenced a NULL pointer in case of OOM. Updated the directory code to use the new & improved version of gfs2_meta_ra() which now returns the first block that was being read. Previously it was releasing it requiring following code to grab the block again at each point it was called. Also turned off readahead on directory lookups since we are reading a hash table, and therefore reading the entries in order is very unlikely. Readahead is still used for all other calls to the directory reading function (e.g. when growing the hash table). Removed the DIO_START constant. Everywhere this was used, it was used to unconditionally start i/o aside from a couple of places, so I've removed it and made the couple of exceptions to this rule into separate functions. Also hunted through the other DIO flags and removed them as arguments from functions which were always called with the same combination of arguments. Updated gfs2_meta_indirect_buffer to be a bit more efficient and hopefully also be a bit easier to read. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
79 lines
2.5 KiB
C
79 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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struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp);
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void gfs2_aspace_put(struct inode *aspace);
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void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai);
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int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags);
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void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai);
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void gfs2_ail_empty_gl(struct gfs2_glock *gl);
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void gfs2_meta_inval(struct gfs2_glock *gl);
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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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void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
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int meta);
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void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh);
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void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
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struct gfs2_ail *ai);
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void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
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void gfs2_meta_cache_flush(struct gfs2_inode *ip);
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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_num.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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void gfs2_meta_syncfs(struct gfs2_sbd *sdp);
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#endif /* __DIO_DOT_H__ */
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