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marcus.erl |
/*
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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,
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uint32_t nelen)
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{
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kernel_lb_addr neloc = {};
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int last_block = (elen + inode->i_sb->s_blocksize - 1) >>
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inode->i_sb->s_blocksize_bits;
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int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>
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inode->i_sb->s_blocksize_bits;
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if (nelen) {
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if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
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udf_free_blocks(inode->i_sb, inode, eloc, 0,
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last_block);
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etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
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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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udf_write_aext(inode, epos, neloc, nelen, 0);
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if (last_block - first_block > 0) {
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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,
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first_block,
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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 = {};
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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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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) =
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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 =
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(struct allocExtDesc *)(epos.bh->b_data);
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aed->lengthAllocDescs =
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cpu_to_le32(epos.offset -
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sizeof(struct allocExtDesc));
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if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
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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,
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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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| 180 |
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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 = {};
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| 184 |
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uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
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| 185 |
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int8_t etype;
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| 186 |
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struct super_block *sb = inode->i_sb;
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| 187 |
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sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
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| 188 |
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loff_t byte_offset;
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| 189 |
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int adsize;
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| 190 |
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| 191 |
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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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| 197 |
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| 198 |
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etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
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| 199 |
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byte_offset = (offset << sb->s_blocksize_bits) +
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| 200 |
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(inode->i_size & (sb->s_blocksize - 1));
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| 201 |
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if (etype != -1) {
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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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| 208 |
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lenalloc = epos.offset - adsize;
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| 209 |
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| 210 |
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if (!epos.bh)
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| 211 |
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lenalloc -= udf_file_entry_alloc_offset(inode);
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else
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| 213 |
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lenalloc -= sizeof(struct allocExtDesc);
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| 214 |
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| 215 |
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while ((etype = udf_current_aext(inode, &epos, &eloc, &elen, 0)) != -1) {
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| 216 |
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if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30)) {
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| 217 |
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udf_write_aext(inode, &epos, neloc, nelen, 0);
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| 218 |
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if (indirect_ext_len) {
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| 219 |
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/* We managed to free all extents in the
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| 220 |
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* indirect extent - free it too */
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| 221 |
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if (!epos.bh)
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| 222 |
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BUG();
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| 223 |
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udf_free_blocks(sb, inode, epos.block,
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| 224 |
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0, indirect_ext_len);
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| 225 |
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} else {
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| 226 |
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if (!epos.bh) {
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| 227 |
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UDF_I_LENALLOC(inode) = lenalloc;
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| 228 |
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mark_inode_dirty(inode);
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| 229 |
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} else {
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| 230 |
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struct allocExtDesc *aed =
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| 231 |
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(struct allocExtDesc *)(epos.bh->b_data);
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| 232 |
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aed->lengthAllocDescs =
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| 233 |
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cpu_to_le32(lenalloc);
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| 234 |
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if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) ||
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| 235 |
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UDF_SB_UDFREV(sb) >= 0x0201)
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| 236 |
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udf_update_tag(epos.bh->b_data,
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| 237 |
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lenalloc +
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| 238 |
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sizeof(struct allocExtDesc));
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| 239 |
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else
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| 240 |
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udf_update_tag(epos.bh->b_data,
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| 241 |
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sizeof(struct allocExtDesc));
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| 242 |
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mark_buffer_dirty_inode(epos.bh, inode);
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| 243 |
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}
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| 244 |
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}
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| 245 |
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brelse(epos.bh);
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| 246 |
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epos.offset = sizeof(struct allocExtDesc);
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| 247 |
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epos.block = eloc;
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| 248 |
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epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, eloc, 0));
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| 249 |
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if (elen)
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| 250 |
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indirect_ext_len = (elen + sb->s_blocksize -1) >>
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| 251 |
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sb->s_blocksize_bits;
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| 252 |
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else
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| 253 |
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indirect_ext_len = 1;
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| 254 |
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} else {
|
| 255 |
|
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extent_trunc(inode, &epos, eloc, etype, elen, 0);
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| 256 |
|
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epos.offset += adsize;
|
| 257 |
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}
|
| 258 |
|
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}
|
| 259 |
|
|
|
| 260 |
|
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if (indirect_ext_len) {
|
| 261 |
|
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if (!epos.bh)
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| 262 |
|
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BUG();
|
| 263 |
|
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udf_free_blocks(sb, inode, epos.block, 0,
|
| 264 |
|
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indirect_ext_len);
|
| 265 |
|
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} else {
|
| 266 |
|
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if (!epos.bh) {
|
| 267 |
|
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UDF_I_LENALLOC(inode) = lenalloc;
|
| 268 |
|
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mark_inode_dirty(inode);
|
| 269 |
|
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} else {
|
| 270 |
|
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struct allocExtDesc *aed =
|
| 271 |
|
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(struct allocExtDesc *)(epos.bh->b_data);
|
| 272 |
|
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aed->lengthAllocDescs = cpu_to_le32(lenalloc);
|
| 273 |
|
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if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) ||
|
| 274 |
|
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UDF_SB_UDFREV(sb) >= 0x0201)
|
| 275 |
|
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udf_update_tag(epos.bh->b_data,
|
| 276 |
|
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lenalloc + sizeof(struct allocExtDesc));
|
| 277 |
|
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else
|
| 278 |
|
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udf_update_tag(epos.bh->b_data,
|
| 279 |
|
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sizeof(struct allocExtDesc));
|
| 280 |
|
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mark_buffer_dirty_inode(epos.bh, inode);
|
| 281 |
|
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}
|
| 282 |
|
|
}
|
| 283 |
|
|
} else if (inode->i_size) {
|
| 284 |
|
|
if (byte_offset) {
|
| 285 |
|
|
kernel_long_ad extent;
|
| 286 |
|
|
|
| 287 |
|
|
/*
|
| 288 |
|
|
* OK, there is not extent covering inode->i_size and
|
| 289 |
|
|
* no extent above inode->i_size => truncate is
|
| 290 |
|
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* extending the file by 'offset' blocks.
|
| 291 |
|
|
*/
|
| 292 |
|
|
if ((!epos.bh &&
|
| 293 |
|
|
epos.offset == udf_file_entry_alloc_offset(inode)) ||
|
| 294 |
|
|
(epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
|
| 295 |
|
|
/* File has no extents at all or has empty last
|
| 296 |
|
|
* indirect extent! Create a fake extent... */
|
| 297 |
|
|
extent.extLocation.logicalBlockNum = 0;
|
| 298 |
|
|
extent.extLocation.partitionReferenceNum = 0;
|
| 299 |
|
|
extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
|
| 300 |
|
|
} else {
|
| 301 |
|
|
epos.offset -= adsize;
|
| 302 |
|
|
etype = udf_next_aext(inode, &epos,
|
| 303 |
|
|
&extent.extLocation,
|
| 304 |
|
|
&extent.extLength, 0);
|
| 305 |
|
|
extent.extLength |= etype << 30;
|
| 306 |
|
|
}
|
| 307 |
|
|
udf_extend_file(inode, &epos, &extent,
|
| 308 |
|
|
offset + ((inode->i_size & (sb->s_blocksize - 1)) != 0));
|
| 309 |
|
|
}
|
| 310 |
|
|
}
|
| 311 |
|
|
UDF_I_LENEXTENTS(inode) = inode->i_size;
|
| 312 |
|
|
|
| 313 |
|
|
brelse(epos.bh);
|
| 314 |
|
|
}
|
