/* * truncate.c * * PURPOSE * Truncate handling routines for the OSTA-UDF(tm) filesystem. * * COPYRIGHT * This file is distributed under the terms of the GNU General Public * License (GPL). Copies of the GPL can be obtained from: * ftp://prep.ai.mit.edu/pub/gnu/GPL * Each contributing author retains all rights to their own work. * * (C) 1999-2004 Ben Fennema * (C) 1999 Stelias Computing Inc * * HISTORY * * 02/24/99 blf Created. * */ #include "udfdecl.h" #include <linux/fs.h> #include <linux/mm.h> #include "udf_i.h" #include "udf_sb.h" static void extent_trunc(struct inode *inode, struct extent_position *epos, struct kernel_lb_addr *eloc, int8_t etype, uint32_t elen, uint32_t nelen) { struct kernel_lb_addr neloc = {}; int last_block = (elen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits; int first_block = (nelen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits; if (nelen) { if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) { udf_free_blocks(inode->i_sb, inode, eloc, 0, last_block); etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30); } else neloc = *eloc; nelen = (etype << 30) | nelen; } if (elen != nelen) { udf_write_aext(inode, epos, &neloc, nelen, 0); if (last_block > first_block) { if (etype == (EXT_RECORDED_ALLOCATED >> 30)) mark_inode_dirty(inode); if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) udf_free_blocks(inode->i_sb, inode, eloc, first_block, last_block - first_block); } } } /* * Truncate the last extent to match i_size. This function assumes * that preallocation extent is already truncated. */ void udf_truncate_tail_extent(struct inode *inode) { struct extent_position epos = {}; struct kernel_lb_addr eloc; uint32_t elen, nelen; uint64_t lbcount = 0; int8_t etype = -1, netype; int adsize; struct udf_inode_info *iinfo = UDF_I(inode); if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB || inode->i_size == iinfo->i_lenExtents) return; /* Are we going to delete the file anyway? */ if (inode->i_nlink == 0) return; if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(struct short_ad); else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); else BUG(); /* Find the last extent in the file */ while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) { etype = netype; lbcount += elen; if (lbcount > inode->i_size) { if (lbcount - inode->i_size >= inode->i_sb->s_blocksize) udf_warn(inode->i_sb, "Too long extent after EOF in inode %u: i_size: %lld lbcount: %lld extent %u+%u\n", (unsigned)inode->i_ino, (long long)inode->i_size, (long long)lbcount, (unsigned)eloc.logicalBlockNum, (unsigned)elen); nelen = elen - (lbcount - inode->i_size); epos.offset -= adsize; extent_trunc(inode, &epos, &eloc, etype, elen, nelen); epos.offset += adsize; if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1) udf_err(inode->i_sb, "Extent after EOF in inode %u\n", (unsigned)inode->i_ino); break; } } /* This inode entry is in-memory only and thus we don't have to mark * the inode dirty */ iinfo->i_lenExtents = inode->i_size; brelse(epos.bh); } void udf_discard_prealloc(struct inode *inode) { struct extent_position epos = { NULL, 0, {0, 0} }; struct kernel_lb_addr eloc; uint32_t elen; uint64_t lbcount = 0; int8_t etype = -1, netype; int adsize; struct udf_inode_info *iinfo = UDF_I(inode); if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB || inode->i_size == iinfo->i_lenExtents) return; if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(struct short_ad); else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); else adsize = 0; epos.block = iinfo->i_location; /* Find the last extent in the file */ while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) { etype = netype; lbcount += elen; } if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) { epos.offset -= adsize; lbcount -= elen; extent_trunc(inode, &epos, &eloc, etype, elen, 0); if (!epos.bh) { iinfo->i_lenAlloc = epos.offset - udf_file_entry_alloc_offset(inode); mark_inode_dirty(inode); } else { struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data); aed->lengthAllocDescs = cpu_to_le32(epos.offset - sizeof(struct allocExtDesc)); if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB(inode->i_sb)->s_udfrev >= 0x0201) udf_update_tag(epos.bh->b_data, epos.offset); else udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc)); mark_buffer_dirty_inode(epos.bh, inode); } } /* This inode entry is in-memory only and thus we don't have to mark * the inode dirty */ iinfo->i_lenExtents = lbcount; brelse(epos.bh); } static void udf_update_alloc_ext_desc(struct inode *inode, struct extent_position *epos, u32 lenalloc) { struct super_block *sb = inode->i_sb; struct udf_sb_info *sbi = UDF_SB(sb); struct allocExtDesc *aed = (struct allocExtDesc *) (epos->bh->b_data); int len = sizeof(struct allocExtDesc); aed->lengthAllocDescs = cpu_to_le32(lenalloc); if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || sbi->s_udfrev >= 0x0201) len += lenalloc; udf_update_tag(epos->bh->b_data, len); mark_buffer_dirty_inode(epos->bh, inode); } /* * Truncate extents of inode to inode->i_size. This function can be used only * for making file shorter. For making file longer, udf_extend_file() has to * be used. */ int udf_truncate_extents(struct inode *inode) { struct extent_position epos; struct kernel_lb_addr eloc, neloc = {}; uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc; int8_t etype; struct super_block *sb = inode->i_sb; sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset; loff_t byte_offset; int adsize; struct udf_inode_info *iinfo = UDF_I(inode); if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(struct short_ad); else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) adsize = sizeof(struct long_ad); else BUG(); etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset); byte_offset = (offset << sb->s_blocksize_bits) + (inode->i_size & (sb->s_blocksize - 1)); if (etype == -1) { /* We should extend the file? */ WARN_ON(byte_offset); return 0; } epos.offset -= adsize; extent_trunc(inode, &epos, &eloc, etype, elen, byte_offset); epos.offset += adsize; if (byte_offset) lenalloc = epos.offset; else lenalloc = epos.offset - adsize; if (!epos.bh) lenalloc -= udf_file_entry_alloc_offset(inode); else lenalloc -= sizeof(struct allocExtDesc); while ((etype = udf_current_aext(inode, &epos, &eloc, &elen, 0)) != -1) { if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30)) { udf_write_aext(inode, &epos, &neloc, nelen, 0); if (indirect_ext_len) { /* We managed to free all extents in the * indirect extent - free it too */ BUG_ON(!epos.bh); udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len); } else if (!epos.bh) { iinfo->i_lenAlloc = lenalloc; mark_inode_dirty(inode); } else udf_update_alloc_ext_desc(inode, &epos, lenalloc); brelse(epos.bh); epos.offset = sizeof(struct allocExtDesc); epos.block = eloc; epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, &eloc, 0)); /* Error reading indirect block? */ if (!epos.bh) return -EIO; if (elen) indirect_ext_len = (elen + sb->s_blocksize - 1) >> sb->s_blocksize_bits; else indirect_ext_len = 1; } else { extent_trunc(inode, &epos, &eloc, etype, elen, 0); epos.offset += adsize; } } if (indirect_ext_len) { BUG_ON(!epos.bh); udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len); } else if (!epos.bh) { iinfo->i_lenAlloc = lenalloc; mark_inode_dirty(inode); } else udf_update_alloc_ext_desc(inode, &epos, lenalloc); iinfo->i_lenExtents = inode->i_size; brelse(epos.bh); return 0; }