Initial import

1 files changed, 313 insertions, 0 deletions

diff --git a/fs/freevxfs/vxfs_lookup.c b/fs/freevxfs/vxfs_lookup.c
new file mode 100644
index 000000000..99c7f0a37
--- /dev/null
+++ b/fs/freevxfs/vxfs_lookup.c
@@ -0,0 +1,313 @@
+/*
+ * Copyright (c) 2000-2001 Christoph Hellwig.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL").
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * 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_CACHE_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 =		vxfs_readdir,
+};
+
+ 
+static inline u_long
+dir_pages(struct inode *inode)
+{
+	return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+}
+ 
+static inline u_long
+dir_blocks(struct inode *ip)
+{
+	u_long			bsize = ip->i_sb->s_blocksize;
+	return (ip->i_size + bsize - 1) & ~(bsize - 1);
+}
+
+/*
+ * NOTE! unlike strncmp, vxfs_match returns 1 for success, 0 for failure.
+ *
+ * len <= VXFS_NAMELEN and de != NULL are guaranteed by caller.
+ */
+static inline int
+vxfs_match(int len, const char * const name, struct vxfs_direct *de)
+{
+	if (len != de->d_namelen)
+		return 0;
+	if (!de->d_ino)
+		return 0;
+	return !memcmp(name, de->d_name, len);
+}
+
+static inline struct vxfs_direct *
+vxfs_next_entry(struct vxfs_direct *de)
+{
+	return ((struct vxfs_direct *)((char*)de + de->d_reclen));
+}
+
+/**
+ * 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				npages, page, nblocks, pblocks, block;
+	u_long				bsize = ip->i_sb->s_blocksize;
+	const char			*name = dp->d_name.name;
+	int				namelen = dp->d_name.len;
+
+	npages = dir_pages(ip);
+	nblocks = dir_blocks(ip);
+	pblocks = VXFS_BLOCK_PER_PAGE(ip->i_sb);
+	
+	for (page = 0; page < npages; page++) {
+		caddr_t			kaddr;
+		struct page		*pp;
+
+		pp = vxfs_get_page(ip->i_mapping, page);
+		if (IS_ERR(pp))
+			continue;
+		kaddr = (caddr_t)page_address(pp);
+
+		for (block = 0; block <= nblocks && block <= pblocks; block++) {
+			caddr_t			baddr, limit;
+			struct vxfs_dirblk	*dbp;
+			struct vxfs_direct	*de;
+
+			baddr = kaddr + (block * bsize);
+			limit = baddr + bsize - VXFS_DIRLEN(1);
+			
+			dbp = (struct vxfs_dirblk *)baddr;
+			de = (struct vxfs_direct *)(baddr + VXFS_DIRBLKOV(dbp));
+
+			for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) {
+				if (!de->d_reclen)
+					break;
+				if (!de->d_ino)
+					continue;
+				if (vxfs_match(namelen, name, de)) {
+					*ppp = pp;
+					return (de);
+				}
+			}
+		}
+		vxfs_put_page(pp);
+	}
+
+	return NULL;
+}
+
+/**
+ * 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 = de->d_ino;
+		kunmap(pp);
+		page_cache_release(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 an 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);
+		if (IS_ERR(ip))
+			return ERR_CAST(ip);
+	}
+	d_add(dp, ip);
+	return NULL;
+}
+
+/**
+ * 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;
+	u_long			page, npages, block, pblocks, nblocks, offset;
+	loff_t			pos;
+
+	if (ctx->pos == 0) {
+		if (!dir_emit_dot(fp, ctx))
+			return 0;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
+			return 0;
+		ctx->pos = 2;
+	}
+	pos = ctx->pos - 2;
+	
+	if (pos > VXFS_DIRROUND(ip->i_size))
+		return 0;
+
+	npages = dir_pages(ip);
+	nblocks = dir_blocks(ip);
+	pblocks = VXFS_BLOCK_PER_PAGE(sbp);
+
+	page = pos >> PAGE_CACHE_SHIFT;
+	offset = pos & ~PAGE_CACHE_MASK;
+	block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks;
+
+	for (; page < npages; page++, block = 0) {
+		char			*kaddr;
+		struct page		*pp;
+
+		pp = vxfs_get_page(ip->i_mapping, page);
+		if (IS_ERR(pp))
+			continue;
+		kaddr = (char *)page_address(pp);
+
+		for (; block <= nblocks && block <= pblocks; block++) {
+			char			*baddr, *limit;
+			struct vxfs_dirblk	*dbp;
+			struct vxfs_direct	*de;
+
+			baddr = kaddr + (block * bsize);
+			limit = baddr + bsize - VXFS_DIRLEN(1);
+	
+			dbp = (struct vxfs_dirblk *)baddr;
+			de = (struct vxfs_direct *)
+				(offset ?
+				 (kaddr + offset) :
+				 (baddr + VXFS_DIRBLKOV(dbp)));
+
+			for (; (char *)de <= limit; de = vxfs_next_entry(de)) {
+				if (!de->d_reclen)
+					break;
+				if (!de->d_ino)
+					continue;
+
+				offset = (char *)de - kaddr;
+				ctx->pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2;
+				if (!dir_emit(ctx, de->d_name, de->d_namelen,
+					de->d_ino, DT_UNKNOWN)) {
+					vxfs_put_page(pp);
+					return 0;
+				}
+			}
+			offset = 0;
+		}
+		vxfs_put_page(pp);
+		offset = 0;
+	}
+	ctx->pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2;
+	return 0;
+}