From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- fs/udf/truncate.c | 286 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 286 insertions(+) create mode 100644 fs/udf/truncate.c (limited to 'fs/udf/truncate.c') diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c new file mode 100644 index 000000000..42b8c5779 --- /dev/null +++ b/fs/udf/truncate.c @@ -0,0 +1,286 @@ +/* + * 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 +#include + +#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 > 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 = {}; + 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. + */ +void 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; + } + 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)); + 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); +} -- cgit v1.2.3-54-g00ecf