summaryrefslogtreecommitdiffstats
path: root/fs/udf/dir.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--fs/udf/dir.c237
1 files changed, 237 insertions, 0 deletions
diff --git a/fs/udf/dir.c b/fs/udf/dir.c
new file mode 100644
index 000000000..d0f92a52e
--- /dev/null
+++ b/fs/udf/dir.c
@@ -0,0 +1,237 @@
+/*
+ * dir.c
+ *
+ * PURPOSE
+ * Directory 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) 1998-2004 Ben Fennema
+ *
+ * HISTORY
+ *
+ * 10/05/98 dgb Split directory operations into its own file
+ * Implemented directory reads via do_udf_readdir
+ * 10/06/98 Made directory operations work!
+ * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG
+ * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading
+ * across blocks.
+ * 12/12/98 Split out the lookup code to namei.c. bulk of directory
+ * code now in directory.c:udf_fileident_read.
+ */
+
+#include "udfdecl.h"
+
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/bio.h>
+#include <linux/iversion.h>
+
+#include "udf_i.h"
+#include "udf_sb.h"
+
+
+static int udf_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct inode *dir = file_inode(file);
+ struct udf_inode_info *iinfo = UDF_I(dir);
+ struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
+ struct fileIdentDesc *fi = NULL;
+ struct fileIdentDesc cfi;
+ udf_pblk_t block, iblock;
+ loff_t nf_pos, emit_pos = 0;
+ int flen;
+ unsigned char *fname = NULL, *copy_name = NULL;
+ unsigned char *nameptr;
+ uint16_t liu;
+ uint8_t lfi;
+ loff_t size = udf_ext0_offset(dir) + dir->i_size;
+ struct buffer_head *tmp, *bha[16];
+ struct kernel_lb_addr eloc;
+ uint32_t elen;
+ sector_t offset;
+ int i, num, ret = 0;
+ struct extent_position epos = { NULL, 0, {0, 0} };
+ struct super_block *sb = dir->i_sb;
+ bool pos_valid = false;
+
+ if (ctx->pos == 0) {
+ if (!dir_emit_dot(file, ctx))
+ return 0;
+ ctx->pos = 1;
+ }
+ nf_pos = (ctx->pos - 1) << 2;
+ if (nf_pos >= size)
+ goto out;
+
+ /*
+ * Something changed since last readdir (either lseek was called or dir
+ * changed)? We need to verify the position correctly points at the
+ * beginning of some dir entry so that the directory parsing code does
+ * not get confused. Since UDF does not have any reliable way of
+ * identifying beginning of dir entry (names are under user control),
+ * we need to scan the directory from the beginning.
+ */
+ if (!inode_eq_iversion(dir, file->f_version)) {
+ emit_pos = nf_pos;
+ nf_pos = 0;
+ } else {
+ pos_valid = true;
+ }
+
+ fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
+ if (!fname) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (nf_pos == 0)
+ nf_pos = udf_ext0_offset(dir);
+
+ fibh.soffset = fibh.eoffset = nf_pos & (sb->s_blocksize - 1);
+ if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
+ if (inode_bmap(dir, nf_pos >> sb->s_blocksize_bits,
+ &epos, &eloc, &elen, &offset)
+ != (EXT_RECORDED_ALLOCATED >> 30)) {
+ ret = -ENOENT;
+ goto out;
+ }
+ block = udf_get_lb_pblock(sb, &eloc, offset);
+ if ((++offset << sb->s_blocksize_bits) < elen) {
+ if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
+ epos.offset -= sizeof(struct short_ad);
+ else if (iinfo->i_alloc_type ==
+ ICBTAG_FLAG_AD_LONG)
+ epos.offset -= sizeof(struct long_ad);
+ } else {
+ offset = 0;
+ }
+
+ if (!(fibh.sbh = fibh.ebh = udf_tread(sb, block))) {
+ ret = -EIO;
+ goto out;
+ }
+
+ if (!(offset & ((16 >> (sb->s_blocksize_bits - 9)) - 1))) {
+ i = 16 >> (sb->s_blocksize_bits - 9);
+ if (i + offset > (elen >> sb->s_blocksize_bits))
+ i = (elen >> sb->s_blocksize_bits) - offset;
+ for (num = 0; i > 0; i--) {
+ block = udf_get_lb_pblock(sb, &eloc, offset + i);
+ tmp = udf_tgetblk(sb, block);
+ if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
+ bha[num++] = tmp;
+ else
+ brelse(tmp);
+ }
+ if (num) {
+ ll_rw_block(REQ_OP_READ, REQ_RAHEAD, num, bha);
+ for (i = 0; i < num; i++)
+ brelse(bha[i]);
+ }
+ }
+ }
+
+ while (nf_pos < size) {
+ struct kernel_lb_addr tloc;
+ loff_t cur_pos = nf_pos;
+
+ /* Update file position only if we got past the current one */
+ if (nf_pos >= emit_pos) {
+ ctx->pos = (nf_pos >> 2) + 1;
+ pos_valid = true;
+ }
+
+ fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
+ &elen, &offset);
+ if (!fi)
+ goto out;
+ /* Still not at offset where user asked us to read from? */
+ if (cur_pos < emit_pos)
+ continue;
+
+ liu = le16_to_cpu(cfi.lengthOfImpUse);
+ lfi = cfi.lengthFileIdent;
+
+ if (fibh.sbh == fibh.ebh) {
+ nameptr = fi->fileIdent + liu;
+ } else {
+ int poffset; /* Unpaded ending offset */
+
+ poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
+
+ if (poffset >= lfi) {
+ nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
+ } else {
+ if (!copy_name) {
+ copy_name = kmalloc(UDF_NAME_LEN,
+ GFP_NOFS);
+ if (!copy_name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ nameptr = copy_name;
+ memcpy(nameptr, fi->fileIdent + liu,
+ lfi - poffset);
+ memcpy(nameptr + lfi - poffset,
+ fibh.ebh->b_data, poffset);
+ }
+ }
+
+ if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
+ if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
+ continue;
+ }
+
+ if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
+ if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
+ continue;
+ }
+
+ if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
+ if (!dir_emit_dotdot(file, ctx))
+ goto out;
+ continue;
+ }
+
+ flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
+ if (flen < 0)
+ continue;
+
+ tloc = lelb_to_cpu(cfi.icb.extLocation);
+ iblock = udf_get_lb_pblock(sb, &tloc, 0);
+ if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN))
+ goto out;
+ } /* end while */
+
+ ctx->pos = (nf_pos >> 2) + 1;
+ pos_valid = true;
+
+out:
+ if (pos_valid)
+ file->f_version = inode_query_iversion(dir);
+ if (fibh.sbh != fibh.ebh)
+ brelse(fibh.ebh);
+ brelse(fibh.sbh);
+ brelse(epos.bh);
+ kfree(fname);
+ kfree(copy_name);
+
+ return ret;
+}
+
+/* readdir and lookup functions */
+const struct file_operations udf_dir_operations = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .iterate_shared = udf_readdir,
+ .unlocked_ioctl = udf_ioctl,
+ .fsync = generic_file_fsync,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 03:43:35 +0000