458 строки
10 KiB
C
458 строки
10 KiB
C
/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2008 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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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/completion.h>
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#include <linux/buffer_head.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/writeback.h>
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#include <linux/swap.h>
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#include <linux/delay.h>
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#include <linux/bio.h>
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#include <linux/gfs2_ondisk.h>
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#include "gfs2.h"
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#include "incore.h"
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#include "glock.h"
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#include "glops.h"
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#include "inode.h"
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#include "log.h"
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#include "lops.h"
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#include "meta_io.h"
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#include "rgrp.h"
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#include "trans.h"
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#include "util.h"
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static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
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{
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struct buffer_head *bh, *head;
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int nr_underway = 0;
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int write_op = REQ_META |
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(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
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BUG_ON(!PageLocked(page));
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BUG_ON(!page_has_buffers(page));
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head = page_buffers(page);
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bh = head;
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do {
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if (!buffer_mapped(bh))
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continue;
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/*
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* If it's a fully non-blocking write attempt and we cannot
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* lock the buffer then redirty the page. Note that this can
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* potentially cause a busy-wait loop from pdflush and kswapd
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* activity, but those code paths have their own higher-level
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* throttling.
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*/
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if (wbc->sync_mode != WB_SYNC_NONE) {
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lock_buffer(bh);
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} else if (!trylock_buffer(bh)) {
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redirty_page_for_writepage(wbc, page);
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continue;
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}
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if (test_clear_buffer_dirty(bh)) {
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mark_buffer_async_write(bh);
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} else {
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unlock_buffer(bh);
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}
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} while ((bh = bh->b_this_page) != head);
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/*
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* The page and its buffers are protected by PageWriteback(), so we can
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* drop the bh refcounts early.
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*/
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BUG_ON(PageWriteback(page));
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set_page_writeback(page);
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do {
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struct buffer_head *next = bh->b_this_page;
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if (buffer_async_write(bh)) {
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submit_bh(write_op, bh);
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nr_underway++;
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}
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bh = next;
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} while (bh != head);
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unlock_page(page);
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if (nr_underway == 0)
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end_page_writeback(page);
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return 0;
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}
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const struct address_space_operations gfs2_meta_aops = {
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.writepage = gfs2_aspace_writepage,
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.releasepage = gfs2_releasepage,
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};
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/**
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* gfs2_meta_sync - Sync all buffers associated with a glock
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* @gl: The glock
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*
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*/
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void gfs2_meta_sync(struct gfs2_glock *gl)
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{
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struct address_space *mapping = gfs2_glock2aspace(gl);
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int error;
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filemap_fdatawrite(mapping);
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error = filemap_fdatawait(mapping);
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if (error)
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gfs2_io_error(gl->gl_sbd);
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}
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/**
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* gfs2_getbuf - Get a buffer with a given address space
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* @gl: the glock
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* @blkno: the block number (filesystem scope)
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* @create: 1 if the buffer should be created
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*
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* Returns: the buffer
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*/
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struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
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{
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struct address_space *mapping = gfs2_glock2aspace(gl);
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struct gfs2_sbd *sdp = gl->gl_sbd;
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struct page *page;
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struct buffer_head *bh;
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unsigned int shift;
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unsigned long index;
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unsigned int bufnum;
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shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
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index = blkno >> shift; /* convert block to page */
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bufnum = blkno - (index << shift); /* block buf index within page */
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if (create) {
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for (;;) {
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page = grab_cache_page(mapping, index);
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if (page)
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break;
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yield();
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}
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} else {
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page = find_lock_page(mapping, index);
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if (!page)
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return NULL;
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}
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if (!page_has_buffers(page))
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create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
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/* Locate header for our buffer within our page */
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for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
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/* Do nothing */;
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get_bh(bh);
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if (!buffer_mapped(bh))
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map_bh(bh, sdp->sd_vfs, blkno);
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unlock_page(page);
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mark_page_accessed(page);
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page_cache_release(page);
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return bh;
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}
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static void meta_prep_new(struct buffer_head *bh)
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{
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struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
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lock_buffer(bh);
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clear_buffer_dirty(bh);
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set_buffer_uptodate(bh);
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unlock_buffer(bh);
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mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
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}
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/**
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* gfs2_meta_new - Get a block
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* @gl: The glock associated with this block
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* @blkno: The block number
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*
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* Returns: The buffer
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*/
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struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
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{
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struct buffer_head *bh;
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bh = gfs2_getbuf(gl, blkno, CREATE);
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meta_prep_new(bh);
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return bh;
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}
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/**
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* gfs2_meta_read - Read a block from disk
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* @gl: The glock covering the block
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* @blkno: The block number
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* @flags: flags
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* @bhp: the place where the buffer is returned (NULL on failure)
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*
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* Returns: errno
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*/
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int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
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struct buffer_head **bhp)
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{
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struct gfs2_sbd *sdp = gl->gl_sbd;
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struct buffer_head *bh;
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if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
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return -EIO;
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*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
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lock_buffer(bh);
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if (buffer_uptodate(bh)) {
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unlock_buffer(bh);
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return 0;
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}
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bh->b_end_io = end_buffer_read_sync;
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get_bh(bh);
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submit_bh(READ_SYNC | REQ_META, bh);
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if (!(flags & DIO_WAIT))
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return 0;
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wait_on_buffer(bh);
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if (unlikely(!buffer_uptodate(bh))) {
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struct gfs2_trans *tr = current->journal_info;
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if (tr && tr->tr_touched)
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gfs2_io_error_bh(sdp, bh);
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brelse(bh);
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return -EIO;
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}
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return 0;
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}
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/**
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* gfs2_meta_wait - Reread a block from disk
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* @sdp: the filesystem
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* @bh: The block to wait for
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*
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* Returns: errno
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*/
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int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
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{
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if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
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return -EIO;
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wait_on_buffer(bh);
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if (!buffer_uptodate(bh)) {
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struct gfs2_trans *tr = current->journal_info;
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if (tr && tr->tr_touched)
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gfs2_io_error_bh(sdp, bh);
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return -EIO;
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}
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if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
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return -EIO;
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return 0;
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}
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/**
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* gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
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* @gl: the glock the buffer belongs to
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* @bh: The buffer to be attached to
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* @meta: Flag to indicate whether its metadata or not
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*/
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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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{
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struct gfs2_bufdata *bd;
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if (meta)
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lock_page(bh->b_page);
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if (bh->b_private) {
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if (meta)
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unlock_page(bh->b_page);
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return;
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}
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bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
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bd->bd_bh = bh;
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bd->bd_gl = gl;
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INIT_LIST_HEAD(&bd->bd_list_tr);
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if (meta)
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lops_init_le(&bd->bd_le, &gfs2_buf_lops);
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else
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lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
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bh->b_private = bd;
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if (meta)
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unlock_page(bh->b_page);
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}
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void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
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{
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struct address_space *mapping = bh->b_page->mapping;
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struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
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struct gfs2_bufdata *bd = bh->b_private;
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if (test_clear_buffer_pinned(bh)) {
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atomic_dec(&sdp->sd_log_pinned);
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list_del_init(&bd->bd_le.le_list);
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if (meta) {
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gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
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sdp->sd_log_num_buf--;
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tr->tr_num_buf_rm++;
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} else {
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gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
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sdp->sd_log_num_databuf--;
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tr->tr_num_databuf_rm++;
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}
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tr->tr_touched = 1;
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brelse(bh);
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}
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if (bd) {
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spin_lock(&sdp->sd_ail_lock);
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if (bd->bd_ail) {
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gfs2_remove_from_ail(bd);
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bh->b_private = NULL;
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bd->bd_bh = NULL;
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bd->bd_blkno = bh->b_blocknr;
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gfs2_trans_add_revoke(sdp, bd);
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}
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spin_unlock(&sdp->sd_ail_lock);
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}
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clear_buffer_dirty(bh);
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clear_buffer_uptodate(bh);
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}
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/**
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* gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
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* @ip: the inode who owns the buffers
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* @bstart: the first buffer in the run
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* @blen: the number of buffers in the run
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*
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*/
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void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
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{
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struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
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struct buffer_head *bh;
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while (blen) {
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bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
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if (bh) {
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lock_buffer(bh);
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gfs2_log_lock(sdp);
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gfs2_remove_from_journal(bh, current->journal_info, 1);
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gfs2_log_unlock(sdp);
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unlock_buffer(bh);
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brelse(bh);
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}
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bstart++;
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blen--;
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}
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}
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/**
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* gfs2_meta_indirect_buffer - Get a metadata buffer
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* @ip: The GFS2 inode
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* @height: The level of this buf in the metadata (indir addr) tree (if any)
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* @num: The block number (device relative) of the buffer
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* @new: Non-zero if we may create a new buffer
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* @bhp: the buffer is returned here
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*
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* Returns: errno
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*/
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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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{
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struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
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struct gfs2_glock *gl = ip->i_gl;
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struct buffer_head *bh;
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int ret = 0;
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if (new) {
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BUG_ON(height == 0);
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bh = gfs2_meta_new(gl, num);
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gfs2_trans_add_bh(ip->i_gl, bh, 1);
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gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
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gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
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} else {
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u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
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ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
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if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
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brelse(bh);
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ret = -EIO;
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}
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}
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*bhp = bh;
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return ret;
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}
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/**
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* gfs2_meta_ra - start readahead on an extent of a file
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* @gl: the glock the blocks belong to
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* @dblock: the starting disk block
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* @extlen: the number of blocks in the extent
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*
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* returns: the first buffer in the extent
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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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{
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struct gfs2_sbd *sdp = gl->gl_sbd;
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struct buffer_head *first_bh, *bh;
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u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
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sdp->sd_sb.sb_bsize_shift;
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BUG_ON(!extlen);
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if (max_ra < 1)
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max_ra = 1;
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if (extlen > max_ra)
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extlen = max_ra;
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first_bh = gfs2_getbuf(gl, dblock, CREATE);
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if (buffer_uptodate(first_bh))
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goto out;
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if (!buffer_locked(first_bh))
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ll_rw_block(READ_SYNC | REQ_META, 1, &first_bh);
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dblock++;
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extlen--;
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while (extlen) {
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bh = gfs2_getbuf(gl, dblock, CREATE);
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if (!buffer_uptodate(bh) && !buffer_locked(bh))
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ll_rw_block(READA, 1, &bh);
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brelse(bh);
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dblock++;
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extlen--;
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if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
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goto out;
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}
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wait_on_buffer(first_bh);
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out:
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return first_bh;
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}
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