1 files changed, 272 insertions, 0 deletions
diff --git a/fs/freevxfs/vxfs_lookup.c b/fs/freevxfs/vxfs_lookup.c
new file mode 100644
index 000000000..f04ba2ed1
--- /dev/null
+++ b/fs/freevxfs/vxfs_lookup.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2000-2001 Christoph Hellwig.
+ * Copyright (c) 2016 Krzysztof Blaszkowski
+ */
+
+/*
+ * Veritas filesystem driver - lookup and other directory related code.
+ */
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/kernel.h>
+#include <linux/pagemap.h>
+
+#include "vxfs.h"
+#include "vxfs_dir.h"
+#include "vxfs_inode.h"
+#include "vxfs_extern.h"
+
+/*
+ * Number of VxFS blocks per page.
+ */
+#define VXFS_BLOCK_PER_PAGE(sbp)  ((PAGE_SIZE / (sbp)->s_blocksize))
+
+
+static struct dentry *	vxfs_lookup(struct inode *, struct dentry *, unsigned int);
+static int		vxfs_readdir(struct file *, struct dir_context *);
+
+const struct inode_operations vxfs_dir_inode_ops = {
+	.lookup =		vxfs_lookup,
+};
+
+const struct file_operations vxfs_dir_operations = {
+	.llseek =		generic_file_llseek,
+	.read =			generic_read_dir,
+	.iterate_shared =	vxfs_readdir,
+};
+
+
+/**
+ * vxfs_find_entry - find a mathing directory entry for a dentry
+ * @ip:		directory inode
+ * @dp:		dentry for which we want to find a direct
+ * @ppp:	gets filled with the page the return value sits in
+ *
+ * Description:
+ *   vxfs_find_entry finds a &struct vxfs_direct for the VFS directory
+ *   cache entry @dp.  @ppp will be filled with the page the return
+ *   value resides in.
+ *
+ * Returns:
+ *   The wanted direct on success, else a NULL pointer.
+ */
+static struct vxfs_direct *
+vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp)
+{
+	u_long bsize = ip->i_sb->s_blocksize;
+	const char *name = dp->d_name.name;
+	int namelen = dp->d_name.len;
+	loff_t limit = VXFS_DIRROUND(ip->i_size);
+	struct vxfs_direct *de_exit = NULL;
+	loff_t pos = 0;
+	struct vxfs_sb_info *sbi = VXFS_SBI(ip->i_sb);
+
+	while (pos < limit) {
+		struct page *pp;
+		char *kaddr;
+		int pg_ofs = pos & ~PAGE_MASK;
+
+		pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
+		if (IS_ERR(pp))
+			return NULL;
+		kaddr = (char *)page_address(pp);
+
+		while (pg_ofs < PAGE_SIZE && pos < limit) {
+			struct vxfs_direct *de;
+
+			if ((pos & (bsize - 1)) < 4) {
+				struct vxfs_dirblk *dbp =
+					(struct vxfs_dirblk *)
+					 (kaddr + (pos & ~PAGE_MASK));
+				int overhead = VXFS_DIRBLKOV(sbi, dbp);
+
+				pos += overhead;
+				pg_ofs += overhead;
+			}
+			de = (struct vxfs_direct *)(kaddr + pg_ofs);
+
+			if (!de->d_reclen) {
+				pos += bsize - 1;
+				pos &= ~(bsize - 1);
+				break;
+			}
+
+			pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
+			pos += fs16_to_cpu(sbi, de->d_reclen);
+			if (!de->d_ino)
+				continue;
+
+			if (namelen != fs16_to_cpu(sbi, de->d_namelen))
+				continue;
+			if (!memcmp(name, de->d_name, namelen)) {
+				*ppp = pp;
+				de_exit = de;
+				break;
+			}
+		}
+		if (!de_exit)
+			vxfs_put_page(pp);
+		else
+			break;
+	}
+
+	return de_exit;
+}
+
+/**
+ * vxfs_inode_by_name - find inode number for dentry
+ * @dip:	directory to search in
+ * @dp:		dentry we search for
+ *
+ * Description:
+ *   vxfs_inode_by_name finds out the inode number of
+ *   the path component described by @dp in @dip.
+ *
+ * Returns:
+ *   The wanted inode number on success, else Zero.
+ */
+static ino_t
+vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
+{
+	struct vxfs_direct		*de;
+	struct page			*pp;
+	ino_t				ino = 0;
+
+	de = vxfs_find_entry(dip, dp, &pp);
+	if (de) {
+		ino = fs32_to_cpu(VXFS_SBI(dip->i_sb), de->d_ino);
+		kunmap(pp);
+		put_page(pp);
+	}
+	
+	return (ino);
+}
+
+/**
+ * vxfs_lookup - lookup pathname component
+ * @dip:	dir in which we lookup
+ * @dp:		dentry we lookup
+ * @flags:	lookup flags
+ *
+ * Description:
+ *   vxfs_lookup tries to lookup the pathname component described
+ *   by @dp in @dip.
+ *
+ * Returns:
+ *   A NULL-pointer on success, else a negative error code encoded
+ *   in the return pointer.
+ */
+static struct dentry *
+vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags)
+{
+	struct inode		*ip = NULL;
+	ino_t			ino;
+			 
+	if (dp->d_name.len > VXFS_NAMELEN)
+		return ERR_PTR(-ENAMETOOLONG);
+				 
+	ino = vxfs_inode_by_name(dip, dp);
+	if (ino)
+		ip = vxfs_iget(dip->i_sb, ino);
+	return d_splice_alias(ip, dp);
+}
+
+/**
+ * vxfs_readdir - read a directory
+ * @fp:		the directory to read
+ * @retp:	return buffer
+ * @filler:	filldir callback
+ *
+ * Description:
+ *   vxfs_readdir fills @retp with directory entries from @fp
+ *   using the VFS supplied callback @filler.
+ *
+ * Returns:
+ *   Zero.
+ */
+static int
+vxfs_readdir(struct file *fp, struct dir_context *ctx)
+{
+	struct inode		*ip = file_inode(fp);
+	struct super_block	*sbp = ip->i_sb;
+	u_long			bsize = sbp->s_blocksize;
+	loff_t			pos, limit;
+	struct vxfs_sb_info	*sbi = VXFS_SBI(sbp);
+
+	if (ctx->pos == 0) {
+		if (!dir_emit_dot(fp, ctx))
+			goto out;
+		ctx->pos++;
+	}
+	if (ctx->pos == 1) {
+		if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
+			goto out;
+		ctx->pos++;
+	}
+
+	limit = VXFS_DIRROUND(ip->i_size);
+	if (ctx->pos > limit)
+		goto out;
+
+	pos = ctx->pos & ~3L;
+
+	while (pos < limit) {
+		struct page *pp;
+		char *kaddr;
+		int pg_ofs = pos & ~PAGE_MASK;
+		int rc = 0;
+
+		pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
+		if (IS_ERR(pp))
+			return -ENOMEM;
+
+		kaddr = (char *)page_address(pp);
+
+		while (pg_ofs < PAGE_SIZE && pos < limit) {
+			struct vxfs_direct *de;
+
+			if ((pos & (bsize - 1)) < 4) {
+				struct vxfs_dirblk *dbp =
+					(struct vxfs_dirblk *)
+					 (kaddr + (pos & ~PAGE_MASK));
+				int overhead = VXFS_DIRBLKOV(sbi, dbp);
+
+				pos += overhead;
+				pg_ofs += overhead;
+			}
+			de = (struct vxfs_direct *)(kaddr + pg_ofs);
+
+			if (!de->d_reclen) {
+				pos += bsize - 1;
+				pos &= ~(bsize - 1);
+				break;
+			}
+
+			pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
+			pos += fs16_to_cpu(sbi, de->d_reclen);
+			if (!de->d_ino)
+				continue;
+
+			rc = dir_emit(ctx, de->d_name,
+					fs16_to_cpu(sbi, de->d_namelen),
+					fs32_to_cpu(sbi, de->d_ino),
+					DT_UNKNOWN);
+			if (!rc) {
+				/* the dir entry was not read, fix pos. */
+				pos -= fs16_to_cpu(sbi, de->d_reclen);
+				break;
+			}
+		}
+		vxfs_put_page(pp);
+		if (!rc)
+			break;
+	}
+
+	ctx->pos = pos | 2;
+
+out:
+	return 0;
+}