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-rw-r--r--fs/udf/truncate.c272
1 files changed, 272 insertions, 0 deletions
diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
new file mode 100644
index 000000000..036ebd892
--- /dev/null
+++ b/fs/udf/truncate.c
@@ -0,0 +1,272 @@
+/*
+ * 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 = {};
+ struct extent_position prev_epos = {};
+ struct kernel_lb_addr eloc;
+ uint32_t elen;
+ uint64_t lbcount = 0;
+ int8_t etype = -1, netype;
+ struct udf_inode_info *iinfo = UDF_I(inode);
+ int bsize = 1 << inode->i_blkbits;
+
+ if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
+ ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))
+ return;
+
+ epos.block = iinfo->i_location;
+
+ /* Find the last extent in the file */
+ while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 0)) != -1) {
+ brelse(prev_epos.bh);
+ prev_epos = epos;
+ if (prev_epos.bh)
+ get_bh(prev_epos.bh);
+
+ etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
+ lbcount += elen;
+ }
+ if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
+ lbcount -= elen;
+ udf_delete_aext(inode, prev_epos);
+ udf_free_blocks(inode->i_sb, inode, &eloc, 0,
+ DIV_ROUND_UP(elen, 1 << inode->i_blkbits));
+ }
+ /* 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);
+ brelse(prev_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_ALLOCDESCS >> 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;
+}
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