317 lines
8.8 KiB
C
317 lines
8.8 KiB
C
/*
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* truncate.c
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*
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* PURPOSE
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* Truncate handling routines for the OSTA-UDF(tm) filesystem.
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*
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* COPYRIGHT
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* This file is distributed under the terms of the GNU General Public
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* License (GPL). Copies of the GPL can be obtained from:
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* ftp://prep.ai.mit.edu/pub/gnu/GPL
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* Each contributing author retains all rights to their own work.
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*
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* (C) 1999-2004 Ben Fennema
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* (C) 1999 Stelias Computing Inc
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*
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* HISTORY
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*
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* 02/24/99 blf Created.
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*
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*/
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#include "udfdecl.h"
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/udf_fs.h>
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#include <linux/buffer_head.h>
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#include "udf_i.h"
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#include "udf_sb.h"
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static void extent_trunc(struct inode * inode, struct extent_position *epos,
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kernel_lb_addr eloc, int8_t etype, uint32_t elen, uint32_t nelen)
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{
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kernel_lb_addr neloc = { 0, 0 };
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int last_block = (elen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
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int first_block = (nelen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
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if (nelen)
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{
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if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
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{
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udf_free_blocks(inode->i_sb, inode, eloc, 0, last_block);
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etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
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}
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else
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neloc = eloc;
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nelen = (etype << 30) | nelen;
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}
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if (elen != nelen)
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{
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udf_write_aext(inode, epos, neloc, nelen, 0);
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if (last_block - first_block > 0)
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{
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if (etype == (EXT_RECORDED_ALLOCATED >> 30))
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mark_inode_dirty(inode);
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if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
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udf_free_blocks(inode->i_sb, inode, eloc, first_block, last_block - first_block);
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}
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}
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}
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/*
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* Truncate the last extent to match i_size. This function assumes
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* that preallocation extent is already truncated.
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*/
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void udf_truncate_tail_extent(struct inode *inode)
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{
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struct extent_position epos = { NULL, 0, {0, 0}};
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kernel_lb_addr eloc;
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uint32_t elen, nelen;
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uint64_t lbcount = 0;
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int8_t etype = -1, netype;
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int adsize;
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if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
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inode->i_size == UDF_I_LENEXTENTS(inode))
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return;
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/* Are we going to delete the file anyway? */
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if (inode->i_nlink == 0)
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return;
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if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
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adsize = sizeof(short_ad);
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else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
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adsize = sizeof(long_ad);
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else
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BUG();
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/* Find the last extent in the file */
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while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1)
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{
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etype = netype;
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lbcount += elen;
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if (lbcount > inode->i_size) {
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if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
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printk(KERN_WARNING
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"udf_truncate_tail_extent(): Too long "
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"extent after EOF in inode %u: i_size: "
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"%Ld lbcount: %Ld extent %u+%u\n",
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(unsigned)inode->i_ino,
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(long long)inode->i_size,
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(long long)lbcount,
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(unsigned)eloc.logicalBlockNum,
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(unsigned)elen);
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nelen = elen - (lbcount - inode->i_size);
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epos.offset -= adsize;
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extent_trunc(inode, &epos, eloc, etype, elen, nelen);
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epos.offset += adsize;
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if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
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printk(KERN_ERR "udf_truncate_tail_extent(): "
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"Extent after EOF in inode %u.\n",
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(unsigned)inode->i_ino);
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break;
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}
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}
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/* This inode entry is in-memory only and thus we don't have to mark
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* the inode dirty */
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UDF_I_LENEXTENTS(inode) = inode->i_size;
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brelse(epos.bh);
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}
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void udf_discard_prealloc(struct inode *inode)
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{
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struct extent_position epos = { NULL, 0, {0, 0}};
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kernel_lb_addr eloc;
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uint32_t elen;
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uint64_t lbcount = 0;
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int8_t etype = -1, netype;
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int adsize;
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if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
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inode->i_size == UDF_I_LENEXTENTS(inode))
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return;
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if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
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adsize = sizeof(short_ad);
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else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
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adsize = sizeof(long_ad);
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else
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adsize = 0;
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epos.block = UDF_I_LOCATION(inode);
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/* Find the last extent in the file */
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while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
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etype = netype;
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lbcount += elen;
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}
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if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
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epos.offset -= adsize;
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lbcount -= elen;
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extent_trunc(inode, &epos, eloc, etype, elen, 0);
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if (!epos.bh) {
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UDF_I_LENALLOC(inode) = epos.offset - udf_file_entry_alloc_offset(inode);
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mark_inode_dirty(inode);
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} else {
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struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data);
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aed->lengthAllocDescs = cpu_to_le32(epos.offset - sizeof(struct allocExtDesc));
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if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
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udf_update_tag(epos.bh->b_data, epos.offset);
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else
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udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc));
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mark_buffer_dirty_inode(epos.bh, inode);
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}
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}
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/* This inode entry is in-memory only and thus we don't have to mark
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* the inode dirty */
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UDF_I_LENEXTENTS(inode) = lbcount;
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brelse(epos.bh);
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}
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void udf_truncate_extents(struct inode * inode)
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{
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struct extent_position epos;
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kernel_lb_addr eloc, neloc = { 0, 0 };
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uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
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int8_t etype;
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struct super_block *sb = inode->i_sb;
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sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
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loff_t byte_offset;
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int adsize;
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if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
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adsize = sizeof(short_ad);
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else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
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adsize = sizeof(long_ad);
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else
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BUG();
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etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
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byte_offset = (offset << sb->s_blocksize_bits) + (inode->i_size & (sb->s_blocksize-1));
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if (etype != -1)
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{
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epos.offset -= adsize;
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extent_trunc(inode, &epos, eloc, etype, elen, byte_offset);
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epos.offset += adsize;
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if (byte_offset)
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lenalloc = epos.offset;
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else
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lenalloc = epos.offset - adsize;
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if (!epos.bh)
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lenalloc -= udf_file_entry_alloc_offset(inode);
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else
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lenalloc -= sizeof(struct allocExtDesc);
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while ((etype = udf_current_aext(inode, &epos, &eloc, &elen, 0)) != -1)
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{
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if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30))
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{
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udf_write_aext(inode, &epos, neloc, nelen, 0);
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if (indirect_ext_len)
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{
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/* We managed to free all extents in the
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* indirect extent - free it too */
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if (!epos.bh)
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BUG();
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udf_free_blocks(sb, inode, epos.block, 0, indirect_ext_len);
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}
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else
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{
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if (!epos.bh)
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{
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UDF_I_LENALLOC(inode) = lenalloc;
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mark_inode_dirty(inode);
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}
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else
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{
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struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data);
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aed->lengthAllocDescs = cpu_to_le32(lenalloc);
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if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(sb) >= 0x0201)
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udf_update_tag(epos.bh->b_data, lenalloc +
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sizeof(struct allocExtDesc));
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else
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udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc));
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mark_buffer_dirty_inode(epos.bh, inode);
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}
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}
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brelse(epos.bh);
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epos.offset = sizeof(struct allocExtDesc);
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epos.block = eloc;
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epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, eloc, 0));
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if (elen)
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indirect_ext_len = (elen +
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sb->s_blocksize - 1) >>
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sb->s_blocksize_bits;
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else
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indirect_ext_len = 1;
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}
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else
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{
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extent_trunc(inode, &epos, eloc, etype, elen, 0);
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epos.offset += adsize;
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}
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}
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if (indirect_ext_len)
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{
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if (!epos.bh)
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BUG();
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udf_free_blocks(sb, inode, epos.block, 0, indirect_ext_len);
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}
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else
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{
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if (!epos.bh)
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{
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UDF_I_LENALLOC(inode) = lenalloc;
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mark_inode_dirty(inode);
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}
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else
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{
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struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data);
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aed->lengthAllocDescs = cpu_to_le32(lenalloc);
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if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(sb) >= 0x0201)
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udf_update_tag(epos.bh->b_data, lenalloc +
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sizeof(struct allocExtDesc));
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else
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udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc));
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mark_buffer_dirty_inode(epos.bh, inode);
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}
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}
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}
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else if (inode->i_size)
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{
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if (byte_offset)
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{
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kernel_long_ad extent;
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/*
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* OK, there is not extent covering inode->i_size and
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* no extent above inode->i_size => truncate is
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* extending the file by 'offset' blocks.
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*/
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if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
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(epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
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/* File has no extents at all or has empty last
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* indirect extent! Create a fake extent... */
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extent.extLocation.logicalBlockNum = 0;
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extent.extLocation.partitionReferenceNum = 0;
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extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
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}
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else {
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epos.offset -= adsize;
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etype = udf_next_aext(inode, &epos,
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&extent.extLocation, &extent.extLength, 0);
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extent.extLength |= etype << 30;
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}
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udf_extend_file(inode, &epos, &extent, offset+((inode->i_size & (sb->s_blocksize-1)) != 0));
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}
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}
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UDF_I_LENEXTENTS(inode) = inode->i_size;
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brelse(epos.bh);
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}
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