1 files changed, 119 insertions, 161 deletions

diff --git a/fs/freevxfs/vxfs_lookup.c b/fs/freevxfs/vxfs_lookup.c
index 25d4099a4aea..1b0bca8b4cc6 100644
--- a/fs/freevxfs/vxfs_lookup.c
+++ b/fs/freevxfs/vxfs_lookup.c
@@ -1,30 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * 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.
+ * Copyright (c) 2016 Krzysztof Blaszkowski
  */
 
 /*
@@ -45,7 +22,7 @@
 /*
  * Number of VxFS blocks per page.
  */
-#define VXFS_BLOCK_PER_PAGE(sbp)  ((PAGE_CACHE_SIZE / (sbp)->s_blocksize))
+#define VXFS_BLOCK_PER_PAGE(sbp)  ((PAGE_SIZE / (sbp)->s_blocksize))
 
 
 static struct dentry *	vxfs_lookup(struct inode *, struct dentry *, unsigned int);
@@ -58,43 +35,9 @@ const struct inode_operations vxfs_dir_inode_ops = {
 const struct file_operations vxfs_dir_operations = {
 	.llseek =		generic_file_llseek,
 	.read =			generic_read_dir,
-	.iterate =		vxfs_readdir,
+	.iterate_shared =	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
@@ -113,50 +56,64 @@ vxfs_next_entry(struct vxfs_direct *de)
 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;
+	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, page);
+		pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
 		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);
-				}
+			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;
 			}
 		}
-		vxfs_put_page(pp);
+		if (!de_exit)
+			vxfs_put_page(pp);
+		else
+			break;
 	}
 
-	return NULL;
+	return de_exit;
 }
 
 /**
@@ -180,9 +137,9 @@ vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
 
 	de = vxfs_find_entry(dip, dp, &pp);
 	if (de) {
-		ino = de->d_ino;
+		ino = fs32_to_cpu(VXFS_SBI(dip->i_sb), de->d_ino);
 		kunmap(pp);
-		page_cache_release(pp);
+		put_page(pp);
 	}
 	
 	return (ino);
@@ -192,14 +149,14 @@ vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
  * vxfs_lookup - lookup pathname component
  * @dip:	dir in which we lookup
  * @dp:		dentry we lookup
- * @nd:		lookup nameidata
+ * @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
+ *   A NULL-pointer on success, else a negative error code encoded
  *   in the return pointer.
  */
 static struct dentry *
@@ -212,20 +169,15 @@ vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags)
 		return ERR_PTR(-ENAMETOOLONG);
 				 
 	ino = vxfs_inode_by_name(dip, dp);
-	if (ino) {
+	if (ino)
 		ip = vxfs_iget(dip->i_sb, ino);
-		if (IS_ERR(ip))
-			return ERR_CAST(ip);
-	}
-	d_add(dp, ip);
-	return NULL;
+	return d_splice_alias(ip, dp);
 }
 
 /**
  * vxfs_readdir - read a directory
  * @fp:		the directory to read
- * @retp:	return buffer
- * @filler:	filldir callback
+ * @ctx:	dir_context for filldir/readdir
  *
  * Description:
  *   vxfs_readdir fills @retp with directory entries from @fp
@@ -240,74 +192,80 @@ 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;
+	loff_t			pos, limit;
+	struct vxfs_sb_info	*sbi = VXFS_SBI(sbp);
 
 	if (ctx->pos == 0) {
 		if (!dir_emit_dot(fp, ctx))
-			return 0;
-		ctx->pos = 1;
+			goto out;
+		ctx->pos++;
 	}
 	if (ctx->pos == 1) {
 		if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
-			return 0;
-		ctx->pos = 2;
+			goto out;
+		ctx->pos++;
 	}
-	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);
+	limit = VXFS_DIRROUND(ip->i_size);
+	if (ctx->pos > limit)
+		goto out;
 
-	page = pos >> PAGE_CACHE_SHIFT;
-	offset = pos & ~PAGE_CACHE_MASK;
-	block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks;
+	pos = ctx->pos & ~3L;
 
-	for (; page < npages; page++, block = 0) {
-		char			*kaddr;
-		struct page		*pp;
+	while (pos < limit) {
+		struct page *pp;
+		char *kaddr;
+		int pg_ofs = pos & ~PAGE_MASK;
+		int rc = 0;
 
-		pp = vxfs_get_page(ip->i_mapping, page);
+		pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
 		if (IS_ERR(pp))
-			continue;
+			return -ENOMEM;
+
 		kaddr = (char *)page_address(pp);
 
-		for (; block <= nblocks && block <= pblocks; block++) {
-			char			*baddr, *limit;
-			struct vxfs_dirblk	*dbp;
-			struct vxfs_direct	*de;
+		while (pg_ofs < PAGE_SIZE && pos < limit) {
+			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;
-				}
+			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;
 			}
-			offset = 0;
 		}
 		vxfs_put_page(pp);
-		offset = 0;
+		if (!rc)
+			break;
 	}
-	ctx->pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2;
+
+	ctx->pos = pos | 2;
+
+out:
 	return 0;
 }