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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /fs/udf/dir.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/udf/dir.c')
-rw-r--r--fs/udf/dir.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/fs/udf/dir.c b/fs/udf/dir.c
new file mode 100644
index 0000000000..f6533f9385
--- /dev/null
+++ b/fs/udf/dir.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * dir.c
+ *
+ * PURPOSE
+ * Directory handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * COPYRIGHT
+ * (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);
+ loff_t nf_pos, emit_pos = 0;
+ int flen;
+ unsigned char *fname = NULL;
+ int ret = 0;
+ struct super_block *sb = dir->i_sb;
+ bool pos_valid = false;
+ struct udf_fileident_iter iter;
+
+ if (ctx->pos == 0) {
+ if (!dir_emit_dot(file, ctx))
+ return 0;
+ ctx->pos = 1;
+ }
+ nf_pos = (ctx->pos - 1) << 2;
+ if (nf_pos >= dir->i_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;
+ }
+
+ for (ret = udf_fiiter_init(&iter, dir, nf_pos);
+ !ret && iter.pos < dir->i_size;
+ ret = udf_fiiter_advance(&iter)) {
+ struct kernel_lb_addr tloc;
+ udf_pblk_t iblock;
+
+ /* Still not at offset where user asked us to read from? */
+ if (iter.pos < emit_pos)
+ continue;
+
+ /* Update file position only if we got past the current one */
+ pos_valid = true;
+ ctx->pos = (iter.pos >> 2) + 1;
+
+ if (iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
+ if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
+ continue;
+ }
+
+ if (iter.fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) {
+ if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
+ continue;
+ }
+
+ if (iter.fi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
+ if (!dir_emit_dotdot(file, ctx))
+ goto out_iter;
+ continue;
+ }
+
+ flen = udf_get_filename(sb, iter.name,
+ iter.fi.lengthFileIdent, fname, UDF_NAME_LEN);
+ if (flen < 0)
+ continue;
+
+ tloc = lelb_to_cpu(iter.fi.icb.extLocation);
+ iblock = udf_get_lb_pblock(sb, &tloc, 0);
+ if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN))
+ goto out_iter;
+ }
+
+ if (!ret) {
+ ctx->pos = (iter.pos >> 2) + 1;
+ pos_valid = true;
+ }
+out_iter:
+ udf_fiiter_release(&iter);
+out:
+ if (pos_valid)
+ file->f_version = inode_query_iversion(dir);
+ kfree(fname);
+
+ 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,
+};