/* * 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 <linux/udf_fs.h> #include <linux/buffer_head.h> #include "udf_i.h" #include "udf_sb.h" static void extent_trunc(struct inode * inode, struct extent_position *epos, kernel_lb_addr eloc, int8_t etype, uint32_t elen, uint32_t nelen) { kernel_lb_addr neloc = { 0, 0 }; 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 > 0) { 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 = { NULL, 0, {0, 0}}; kernel_lb_addr eloc; uint32_t elen, nelen; uint64_t lbcount = 0; int8_t etype = -1, netype; int adsize; if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB || inode->i_size == UDF_I_LENEXTENTS(inode)) return; /* Are we going to delete the file anyway? */ if (inode->i_nlink == 0) return; if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(short_ad); else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG) adsize = sizeof(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) printk(KERN_WARNING "udf_truncate_tail_extent(): Too long " "extent after EOF in inode %u: i_size: " "%Ld lbcount: %Ld 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) printk(KERN_ERR "udf_truncate_tail_extent(): " "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 */ UDF_I_LENEXTENTS(inode) = inode->i_size; brelse(epos.bh); } void udf_discard_prealloc(struct inode *inode) { struct extent_position epos = { NULL, 0, {0, 0}}; kernel_lb_addr eloc; uint32_t elen; uint64_t lbcount = 0; int8_t etype = -1, netype; int adsize; if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB || inode->i_size == UDF_I_LENEXTENTS(inode)) return; if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(short_ad); else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG) adsize = sizeof(long_ad); else adsize = 0; epos.block = UDF_I_LOCATION(inode); /* 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) { UDF_I_LENALLOC(inode) = 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_UDFREV(inode->i_sb) >= 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 */ UDF_I_LENEXTENTS(inode) = lbcount; brelse(epos.bh); } void udf_truncate_extents(struct inode * inode) { struct extent_position epos; kernel_lb_addr eloc, neloc = { 0, 0 }; 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; if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT) adsize = sizeof(short_ad); else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG) adsize = sizeof(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) { 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 */ if (!epos.bh) BUG(); udf_free_blocks(sb, inode, epos.block, 0, indirect_ext_len); } else { if (!epos.bh) { UDF_I_LENALLOC(inode) = lenalloc; mark_inode_dirty(inode); } else { struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data); aed->lengthAllocDescs = cpu_to_le32(lenalloc); if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(sb) >= 0x0201) udf_update_tag(epos.bh->b_data, lenalloc + sizeof(struct allocExtDesc)); else udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc)); mark_buffer_dirty_inode(epos.bh, inode); } } brelse(epos.bh); epos.offset = sizeof(struct allocExtDesc); epos.block = eloc; epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, eloc, 0)); 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) { if (!epos.bh) BUG(); udf_free_blocks(sb, inode, epos.block, 0, indirect_ext_len); } else { if (!epos.bh) { UDF_I_LENALLOC(inode) = lenalloc; mark_inode_dirty(inode); } else { struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data); aed->lengthAllocDescs = cpu_to_le32(lenalloc); if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(sb) >= 0x0201) udf_update_tag(epos.bh->b_data, lenalloc + sizeof(struct allocExtDesc)); else udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc)); mark_buffer_dirty_inode(epos.bh, inode); } } } else if (inode->i_size) { if (byte_offset) { kernel_long_ad extent; /* * OK, there is not extent covering inode->i_size and * no extent above inode->i_size => truncate is * extending the file by 'offset' blocks. */ if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) || (epos.bh && epos.offset == sizeof(struct allocExtDesc))) { /* File has no extents at all or has empty last * indirect extent! Create a fake extent... */ extent.extLocation.logicalBlockNum = 0; extent.extLocation.partitionReferenceNum = 0; extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED; } else { epos.offset -= adsize; etype = udf_next_aext(inode, &epos, &extent.extLocation, &extent.extLength, 0); extent.extLength |= etype << 30; } udf_extend_file(inode, &epos, &extent, offset+((inode->i_size & (sb->s_blocksize-1)) != 0)); } } UDF_I_LENEXTENTS(inode) = inode->i_size; brelse(epos.bh); }