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-rw-r--r--fs/udf/truncate.c284
1 files changed, 284 insertions, 0 deletions
diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
new file mode 100644
index 0000000..7dc8a55
--- /dev/null
+++ b/fs/udf/truncate.c
@@ -0,0 +1,284 @@
+/*
+ * truncate.c
+ *
+ * PURPOSE
+ * Truncate handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * CONTACTS
+ * E-mail regarding any portion of the Linux UDF file system should be
+ * directed to the development team mailing list (run by majordomo):
+ * linux_udf@hpesjro.fc.hp.com
+ *
+ * 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, kernel_lb_addr bloc, int extoffset,
+ kernel_lb_addr eloc, int8_t etype, uint32_t elen, struct buffer_head *bh, 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, bloc, &extoffset, neloc, nelen, bh, 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);
+ }
+ }
+}
+
+void udf_discard_prealloc(struct inode * inode)
+{
+ kernel_lb_addr bloc, eloc;
+ uint32_t extoffset = 0, elen, nelen;
+ uint64_t lbcount = 0;
+ int8_t etype = -1, netype;
+ struct buffer_head *bh = NULL;
+ 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;
+
+ bloc = UDF_I_LOCATION(inode);
+
+ while ((netype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
+ {
+ etype = netype;
+ lbcount += elen;
+ if (lbcount > inode->i_size && lbcount - inode->i_size < inode->i_sb->s_blocksize)
+ {
+ nelen = elen - (lbcount - inode->i_size);
+ extent_trunc(inode, bloc, extoffset-adsize, eloc, etype, elen, bh, nelen);
+ lbcount = inode->i_size;
+ }
+ }
+ if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
+ {
+ extoffset -= adsize;
+ lbcount -= elen;
+ extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
+ if (!bh)
+ {
+ UDF_I_LENALLOC(inode) = extoffset - udf_file_entry_alloc_offset(inode);
+ mark_inode_dirty(inode);
+ }
+ else
+ {
+ struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
+ aed->lengthAllocDescs = cpu_to_le32(extoffset - sizeof(struct allocExtDesc));
+ if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
+ udf_update_tag(bh->b_data, extoffset);
+ else
+ udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
+ mark_buffer_dirty_inode(bh, inode);
+ }
+ }
+ UDF_I_LENEXTENTS(inode) = lbcount;
+
+ udf_release_data(bh);
+}
+
+void udf_truncate_extents(struct inode * inode)
+{
+ kernel_lb_addr bloc, eloc, neloc = { 0, 0 };
+ uint32_t extoffset, elen, offset, nelen = 0, lelen = 0, lenalloc;
+ int8_t etype;
+ int first_block = inode->i_size >> inode->i_sb->s_blocksize_bits;
+ struct buffer_head *bh = NULL;
+ 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
+ adsize = 0;
+
+ etype = inode_bmap(inode, first_block, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
+ offset += (inode->i_size & (inode->i_sb->s_blocksize - 1));
+ if (etype != -1)
+ {
+ extoffset -= adsize;
+ extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, offset);
+ extoffset += adsize;
+
+ if (offset)
+ lenalloc = extoffset;
+ else
+ lenalloc = extoffset - adsize;
+
+ if (!bh)
+ lenalloc -= udf_file_entry_alloc_offset(inode);
+ else
+ lenalloc -= sizeof(struct allocExtDesc);
+
+ while ((etype = udf_current_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 0)) != -1)
+ {
+ if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30))
+ {
+ udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 0);
+ extoffset = 0;
+ if (lelen)
+ {
+ if (!bh)
+ BUG();
+ else
+ memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
+ udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
+ }
+ else
+ {
+ if (!bh)
+ {
+ UDF_I_LENALLOC(inode) = lenalloc;
+ mark_inode_dirty(inode);
+ }
+ else
+ {
+ struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
+ aed->lengthAllocDescs = cpu_to_le32(lenalloc);
+ if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
+ udf_update_tag(bh->b_data, lenalloc +
+ sizeof(struct allocExtDesc));
+ else
+ udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
+ mark_buffer_dirty_inode(bh, inode);
+ }
+ }
+
+ udf_release_data(bh);
+ extoffset = sizeof(struct allocExtDesc);
+ bloc = eloc;
+ bh = udf_tread(inode->i_sb, udf_get_lb_pblock(inode->i_sb, bloc, 0));
+ if (elen)
+ lelen = (elen + inode->i_sb->s_blocksize - 1) >>
+ inode->i_sb->s_blocksize_bits;
+ else
+ lelen = 1;
+ }
+ else
+ {
+ extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
+ extoffset += adsize;
+ }
+ }
+
+ if (lelen)
+ {
+ if (!bh)
+ BUG();
+ else
+ memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
+ udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
+ }
+ else
+ {
+ if (!bh)
+ {
+ UDF_I_LENALLOC(inode) = lenalloc;
+ mark_inode_dirty(inode);
+ }
+ else
+ {
+ struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
+ aed->lengthAllocDescs = cpu_to_le32(lenalloc);
+ if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
+ udf_update_tag(bh->b_data, lenalloc +
+ sizeof(struct allocExtDesc));
+ else
+ udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
+ mark_buffer_dirty_inode(bh, inode);
+ }
+ }
+ }
+ else if (inode->i_size)
+ {
+ if (offset)
+ {
+ extoffset -= adsize;
+ etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
+ if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
+ {
+ extoffset -= adsize;
+ elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + offset);
+ udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
+ }
+ else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
+ {
+ kernel_lb_addr neloc = { 0, 0 };
+ extoffset -= adsize;
+ nelen = EXT_NOT_RECORDED_NOT_ALLOCATED |
+ ((elen + offset + inode->i_sb->s_blocksize - 1) &
+ ~(inode->i_sb->s_blocksize - 1));
+ udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
+ udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1);
+ }
+ else
+ {
+ if (elen & (inode->i_sb->s_blocksize - 1))
+ {
+ extoffset -= adsize;
+ elen = EXT_RECORDED_ALLOCATED |
+ ((elen + inode->i_sb->s_blocksize - 1) &
+ ~(inode->i_sb->s_blocksize - 1));
+ udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1);
+ }
+ memset(&eloc, 0x00, sizeof(kernel_lb_addr));
+ elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset;
+ udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
+ }
+ }
+ }
+ UDF_I_LENEXTENTS(inode) = inode->i_size;
+
+ udf_release_data(bh);
+}
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