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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * truncate.c4 *5 * PURPOSE6 * Truncate handling routines for the OSTA-UDF(tm) filesystem.7 *8 * COPYRIGHT9 * (C) 1999-2004 Ben Fennema10 * (C) 1999 Stelias Computing Inc11 *12 * HISTORY13 *14 * 02/24/99 blf Created.15 *16 */17 18#include "udfdecl.h"19#include <linux/fs.h>20#include <linux/mm.h>21 22#include "udf_i.h"23#include "udf_sb.h"24 25static void extent_trunc(struct inode *inode, struct extent_position *epos,26 struct kernel_lb_addr *eloc, int8_t etype, uint32_t elen,27 uint32_t nelen)28{29 struct kernel_lb_addr neloc = {};30 int last_block = (elen + inode->i_sb->s_blocksize - 1) >>31 inode->i_sb->s_blocksize_bits;32 int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>33 inode->i_sb->s_blocksize_bits;34 35 if (nelen) {36 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {37 udf_free_blocks(inode->i_sb, inode, eloc, 0,38 last_block);39 etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);40 } else41 neloc = *eloc;42 nelen = (etype << 30) | nelen;43 }44 45 if (elen != nelen) {46 udf_write_aext(inode, epos, &neloc, nelen, 0);47 if (last_block > first_block) {48 if (etype == (EXT_RECORDED_ALLOCATED >> 30))49 mark_inode_dirty(inode);50 51 if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))52 udf_free_blocks(inode->i_sb, inode, eloc,53 first_block,54 last_block - first_block);55 }56 }57}58 59/*60 * Truncate the last extent to match i_size. This function assumes61 * that preallocation extent is already truncated.62 */63void udf_truncate_tail_extent(struct inode *inode)64{65 struct extent_position epos = {};66 struct kernel_lb_addr eloc;67 uint32_t elen, nelen;68 uint64_t lbcount = 0;69 int8_t etype = -1, netype;70 int adsize;71 struct udf_inode_info *iinfo = UDF_I(inode);72 int ret;73 74 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||75 inode->i_size == iinfo->i_lenExtents)76 return;77 /* Are we going to delete the file anyway? */78 if (inode->i_nlink == 0)79 return;80 81 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)82 adsize = sizeof(struct short_ad);83 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)84 adsize = sizeof(struct long_ad);85 else86 BUG();87 88 /* Find the last extent in the file */89 while (1) {90 ret = udf_next_aext(inode, &epos, &eloc, &elen, &netype, 1);91 if (ret <= 0)92 break;93 etype = netype;94 lbcount += elen;95 if (lbcount > inode->i_size) {96 if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)97 udf_warn(inode->i_sb,98 "Too long extent after EOF in inode %u: i_size: %lld lbcount: %lld extent %u+%u\n",99 (unsigned)inode->i_ino,100 (long long)inode->i_size,101 (long long)lbcount,102 (unsigned)eloc.logicalBlockNum,103 (unsigned)elen);104 nelen = elen - (lbcount - inode->i_size);105 epos.offset -= adsize;106 extent_trunc(inode, &epos, &eloc, etype, elen, nelen);107 epos.offset += adsize;108 if (udf_next_aext(inode, &epos, &eloc, &elen,109 &netype, 1) > 0)110 udf_err(inode->i_sb,111 "Extent after EOF in inode %u\n",112 (unsigned)inode->i_ino);113 break;114 }115 }116 /* This inode entry is in-memory only and thus we don't have to mark117 * the inode dirty */118 if (ret == 0)119 iinfo->i_lenExtents = inode->i_size;120 brelse(epos.bh);121}122 123void udf_discard_prealloc(struct inode *inode)124{125 struct extent_position epos = {};126 struct extent_position prev_epos = {};127 struct kernel_lb_addr eloc;128 uint32_t elen;129 uint64_t lbcount = 0;130 int8_t etype = -1;131 struct udf_inode_info *iinfo = UDF_I(inode);132 int bsize = i_blocksize(inode);133 int8_t tmpetype = -1;134 int ret;135 136 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||137 ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))138 return;139 140 epos.block = iinfo->i_location;141 142 /* Find the last extent in the file */143 while (1) {144 ret = udf_next_aext(inode, &epos, &eloc, &elen, &tmpetype, 0);145 if (ret < 0)146 goto out;147 if (ret == 0)148 break;149 brelse(prev_epos.bh);150 prev_epos = epos;151 if (prev_epos.bh)152 get_bh(prev_epos.bh);153 154 ret = udf_next_aext(inode, &epos, &eloc, &elen, &etype, 1);155 if (ret < 0)156 goto out;157 lbcount += elen;158 }159 160 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {161 lbcount -= elen;162 udf_delete_aext(inode, prev_epos);163 udf_free_blocks(inode->i_sb, inode, &eloc, 0,164 DIV_ROUND_UP(elen, bsize));165 }166 /* This inode entry is in-memory only and thus we don't have to mark167 * the inode dirty */168 iinfo->i_lenExtents = lbcount;169out:170 brelse(epos.bh);171 brelse(prev_epos.bh);172}173 174static void udf_update_alloc_ext_desc(struct inode *inode,175 struct extent_position *epos,176 u32 lenalloc)177{178 struct super_block *sb = inode->i_sb;179 struct udf_sb_info *sbi = UDF_SB(sb);180 181 struct allocExtDesc *aed = (struct allocExtDesc *) (epos->bh->b_data);182 int len = sizeof(struct allocExtDesc);183 184 aed->lengthAllocDescs = cpu_to_le32(lenalloc);185 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || sbi->s_udfrev >= 0x0201)186 len += lenalloc;187 188 udf_update_tag(epos->bh->b_data, len);189 mark_buffer_dirty_inode(epos->bh, inode);190}191 192/*193 * Truncate extents of inode to inode->i_size. This function can be used only194 * for making file shorter. For making file longer, udf_extend_file() has to195 * be used.196 */197int udf_truncate_extents(struct inode *inode)198{199 struct extent_position epos;200 struct kernel_lb_addr eloc, neloc = {};201 uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;202 int8_t etype;203 struct super_block *sb = inode->i_sb;204 sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;205 loff_t byte_offset;206 int adsize;207 struct udf_inode_info *iinfo = UDF_I(inode);208 int ret = 0;209 210 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)211 adsize = sizeof(struct short_ad);212 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)213 adsize = sizeof(struct long_ad);214 else215 BUG();216 217 ret = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset, &etype);218 if (ret < 0)219 return ret;220 byte_offset = (offset << sb->s_blocksize_bits) +221 (inode->i_size & (sb->s_blocksize - 1));222 if (ret == 0) {223 /* We should extend the file? */224 WARN_ON(byte_offset);225 return 0;226 }227 epos.offset -= adsize;228 extent_trunc(inode, &epos, &eloc, etype, elen, byte_offset);229 epos.offset += adsize;230 if (byte_offset)231 lenalloc = epos.offset;232 else233 lenalloc = epos.offset - adsize;234 235 if (!epos.bh)236 lenalloc -= udf_file_entry_alloc_offset(inode);237 else238 lenalloc -= sizeof(struct allocExtDesc);239 240 while ((ret = udf_current_aext(inode, &epos, &eloc,241 &elen, &etype, 0)) > 0) {242 if (etype == (EXT_NEXT_EXTENT_ALLOCDESCS >> 30)) {243 udf_write_aext(inode, &epos, &neloc, nelen, 0);244 if (indirect_ext_len) {245 /* We managed to free all extents in the246 * indirect extent - free it too */247 BUG_ON(!epos.bh);248 udf_free_blocks(sb, NULL, &epos.block,249 0, indirect_ext_len);250 } else if (!epos.bh) {251 iinfo->i_lenAlloc = lenalloc;252 mark_inode_dirty(inode);253 } else254 udf_update_alloc_ext_desc(inode,255 &epos, lenalloc);256 brelse(epos.bh);257 epos.offset = sizeof(struct allocExtDesc);258 epos.block = eloc;259 epos.bh = sb_bread(sb,260 udf_get_lb_pblock(sb, &eloc, 0));261 /* Error reading indirect block? */262 if (!epos.bh)263 return -EIO;264 if (elen)265 indirect_ext_len =266 (elen + sb->s_blocksize - 1) >>267 sb->s_blocksize_bits;268 else269 indirect_ext_len = 1;270 } else {271 extent_trunc(inode, &epos, &eloc, etype, elen, 0);272 epos.offset += adsize;273 }274 }275 276 if (ret < 0) {277 brelse(epos.bh);278 return ret;279 }280 281 if (indirect_ext_len) {282 BUG_ON(!epos.bh);283 udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len);284 } else if (!epos.bh) {285 iinfo->i_lenAlloc = lenalloc;286 mark_inode_dirty(inode);287 } else288 udf_update_alloc_ext_desc(inode, &epos, lenalloc);289 iinfo->i_lenExtents = inode->i_size;290 291 brelse(epos.bh);292 return 0;293}294