fs/adfs: dir: add generic directory reading

Both directory formats code the mechanics of fetching the directory
buffers using their own implementations.  Consolidate these into one
implementation.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/adfs/adfs.h

@@ -170,6 +170,8 @@ int adfs_dir_copyfrom(void *dst, struct adfs_dir *dir, unsigned int offset,
 int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src,
 		    size_t len);
 void adfs_dir_relse(struct adfs_dir *dir);
+int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
+			  unsigned int size, struct adfs_dir *dir);
 void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj);
 extern int adfs_dir_update(struct super_block *sb, struct object_info *obj,
 			   int wait);

fs/adfs/dir.c

@@ -78,6 +78,55 @@ void adfs_dir_relse(struct adfs_dir *dir)
 	dir->sb = NULL;
 }
 
+int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
+			  unsigned int size, struct adfs_dir *dir)
+{
+	struct buffer_head **bhs;
+	unsigned int i, num;
+	int block;
+
+	num = ALIGN(size, sb->s_blocksize) >> sb->s_blocksize_bits;
+	if (num > ARRAY_SIZE(dir->bh)) {
+		/* We only allow one extension */
+		if (dir->bhs != dir->bh)
+			return -EINVAL;
+
+		bhs = kcalloc(num, sizeof(*bhs), GFP_KERNEL);
+		if (!bhs)
+			return -ENOMEM;
+
+		if (dir->nr_buffers)
+			memcpy(bhs, dir->bhs, dir->nr_buffers * sizeof(*bhs));
+
+		dir->bhs = bhs;
+	}
+
+	for (i = dir->nr_buffers; i < num; i++) {
+		block = __adfs_block_map(sb, indaddr, i);
+		if (!block) {
+			adfs_error(sb, "dir %06x has a hole at offset %u",
+				   indaddr, i);
+			goto error;
+		}
+
+		dir->bhs[i] = sb_bread(sb, block);
+		if (!dir->bhs[i]) {
+			adfs_error(sb,
+				   "dir %06x failed read at offset %u, mapped block 0x%08x",
+				   indaddr, i, block);
+			goto error;
+		}
+
+		dir->nr_buffers++;
+	}
+	return 0;
+
+error:
+	adfs_dir_relse(dir);
+
+	return -EIO;
+}
+
 static int adfs_dir_read(struct super_block *sb, u32 indaddr,
 			 unsigned int size, struct adfs_dir *dir)
 {

fs/adfs/dir_f.c

@@ -126,7 +126,7 @@ static int adfs_dir_read(struct super_block *sb, u32 indaddr,
 			 unsigned int size, struct adfs_dir *dir)
 {
 	const unsigned int blocksize_bits = sb->s_blocksize_bits;
-	int blk;
+	int ret;
 
 	/*
 	 * Directories which are not a multiple of 2048 bytes
@@ -135,24 +135,9 @@ static int adfs_dir_read(struct super_block *sb, u32 indaddr,
 	if (size & 2047)
 		goto bad_dir;
 
-	size >>= blocksize_bits;
-
-	for (blk = 0; blk < size; blk++) {
-		int phys;
-
-		phys = __adfs_block_map(sb, indaddr, blk);
-		if (!phys) {
-			adfs_error(sb, "dir %06x has a hole at offset %d",
-				   indaddr, blk);
-			goto release_buffers;
-		}
-
-		dir->bh[blk] = sb_bread(sb, phys);
-		if (!dir->bh[blk])
-			goto release_buffers;
-
-		dir->nr_buffers += 1;
-	}
+	ret = adfs_dir_read_buffers(sb, indaddr, size, dir);
+	if (ret)
+		return ret;
 
 	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
 	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
@@ -172,7 +157,6 @@ static int adfs_dir_read(struct super_block *sb, u32 indaddr,
 
 bad_dir:
 	adfs_error(sb, "dir %06x is corrupted", indaddr);
-release_buffers:
 	adfs_dir_relse(dir);
 
 	return -EIO;

fs/adfs/dir_fplus.c

@@ -4,87 +4,49 @@
  *
  *  Copyright (C) 1997-1999 Russell King
  */
-#include <linux/slab.h>
 #include "adfs.h"
 #include "dir_fplus.h"
 
-static int
-adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
+static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
+			   unsigned int size, struct adfs_dir *dir)
 {
 	struct adfs_bigdirheader *h;
 	struct adfs_bigdirtail *t;
-	unsigned long block;
-	unsigned int blk, size;
-	int ret = -EIO;
-
-	block = __adfs_block_map(sb, id, 0);
-	if (!block) {
-		adfs_error(sb, "dir object %X has a hole at offset 0", id);
-		goto out;
-	}
+	unsigned int dirsize;
+	int ret;
 
-	dir->bhs[0] = sb_bread(sb, block);
-	if (!dir->bhs[0])
-		goto out;
-	dir->nr_buffers += 1;
+	/* Read first buffer */
+	ret = adfs_dir_read_buffers(sb, indaddr, sb->s_blocksize, dir);
+	if (ret)
+		return ret;
 
 	h = (struct adfs_bigdirheader *)dir->bhs[0]->b_data;
-	size = le32_to_cpu(h->bigdirsize);
-	if (size != sz) {
+	dirsize = le32_to_cpu(h->bigdirsize);
+	if (dirsize != size) {
 		adfs_msg(sb, KERN_WARNING,
-			 "directory header size %X does not match directory size %X",
-			 size, sz);
+			 "dir %06x header size %X does not match directory size %X",
+			 indaddr, dirsize, size);
 	}
 
 	if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
 	    h->bigdirversion[2] != 0 || size & 2047 ||
 	    h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME)) {
-		adfs_error(sb, "dir %06x has malformed header", id);
+		adfs_error(sb, "dir %06x has malformed header", indaddr);
 		goto out;
 	}
 
-	size >>= sb->s_blocksize_bits;
-	if (size > ARRAY_SIZE(dir->bh)) {
-		/* this directory is too big for fixed bh set, must allocate */
-		struct buffer_head **bhs =
-			kcalloc(size, sizeof(struct buffer_head *),
-				GFP_KERNEL);
-		if (!bhs) {
-			adfs_msg(sb, KERN_ERR,
-				 "not enough memory for dir object %X (%d blocks)",
-				 id, size);
-			ret = -ENOMEM;
-			goto out;
-		}
-		dir->bhs = bhs;
-		/* copy over the pointer to the block that we've already read */
-		dir->bhs[0] = dir->bh[0];
-	}
-
-	for (blk = 1; blk < size; blk++) {
-		block = __adfs_block_map(sb, id, blk);
-		if (!block) {
-			adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
-			goto out;
-		}
-
-		dir->bhs[blk] = sb_bread(sb, block);
-		if (!dir->bhs[blk]) {
-			adfs_error(sb,	"dir object %x failed read for offset %d, mapped block %lX",
-				   id, blk, block);
-			goto out;
-		}
-
-		dir->nr_buffers += 1;
-	}
+	/* Read remaining buffers */
+	ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir);
+	if (ret)
+		return ret;
 
 	t = (struct adfs_bigdirtail *)
-		(dir->bhs[size - 1]->b_data + (sb->s_blocksize - 8));
+		(dir->bhs[dir->nr_buffers - 1]->b_data + (sb->s_blocksize - 8));
 
 	if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
 	    t->bigdirendmasseq != h->startmasseq ||
 	    t->reserved[0] != 0 || t->reserved[1] != 0) {
-		adfs_error(sb, "dir %06x has malformed tail", id);
+		adfs_error(sb, "dir %06x has malformed tail", indaddr);
 		goto out;
 	}