[PATCH v12 02/11] ext4: replace ext4_dir_entry with ext4_dir_entry_2

From: Artem Blagodarenko <[email protected]>

Replace remaining uses of struct ext4_dir_entry in namei.c
with struct ext4_dir_entry_2.

The code paths affected by this change already depend on the
filetype feature, so using struct ext4_dir_entry_2 is
appropriate and avoids mixing the two directory entry types
unnecessarily.

This change does not affect support for 16-bit rec_len.

Signed-off-by: Artem Blagodarenko <[email protected]>
Reviewed-by: Andreas Dilger <[email protected]>
---
 fs/ext4/ext4.h  |  6 ++----
 fs/ext4/namei.c | 38 +++++++++++++++++++-------------------
 2 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b37c136ea3ab..aa8a37566a38 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2472,10 +2472,8 @@ static inline int ext4_emergency_state(struct super_block *sb)
  * Structure of a directory entry
  */
 #define EXT4_NAME_LEN 255
-/*
- * Base length of the ext4 directory entry excluding the name length
- */
-#define EXT4_BASE_DIR_LEN (sizeof(struct ext4_dir_entry_2) - EXT4_NAME_LEN)
+/* offsetof avoids sizeof()+padding giving 9 instead of the correct on-disk 8 */
+#define EXT4_BASE_DIR_LEN offsetof(struct ext4_dir_entry_2, name)
 
 struct ext4_dir_entry {
 	__le32	inode;			/* Inode number */
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a283e285937a..c2f330c75c81 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -102,7 +102,7 @@ static struct buffer_head *ext4_append(handle_t *handle,
 }
 
 static int ext4_dx_csum_verify(struct inode *inode,
-			       struct ext4_dir_entry *dirent);
+			       struct ext4_dir_entry_2 *dirent);
 
 /*
  * Hints to ext4_read_dirblock regarding whether we expect a directory
@@ -128,7 +128,7 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 						unsigned int line)
 {
 	struct buffer_head *bh;
-	struct ext4_dir_entry *dirent;
+	struct ext4_dir_entry_2 *dirent;
 	int is_dx_block = 0;
 
 	if (block >= inode->i_size >> inode->i_blkbits) {
@@ -160,7 +160,7 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 	}
 	if (!bh)
 		return NULL;
-	dirent = (struct ext4_dir_entry *) bh->b_data;
+	dirent = (struct ext4_dir_entry_2 *) bh->b_data;
 	/* Determine whether or not we have an index block */
 	if (is_dx(inode)) {
 		if (block == 0)
@@ -317,13 +317,13 @@ static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
 
 #ifdef PARANOID
-	struct ext4_dir_entry *d, *top;
+	struct ext4_dir_entry_2 *d, *top;
 
-	d = (struct ext4_dir_entry *)bh->b_data;
-	top = (struct ext4_dir_entry *)(bh->b_data +
+	d = (struct ext4_dir_entry_2 *)bh->b_data;
+	top = (struct ext4_dir_entry_2 *)(bh->b_data +
 		(blocksize - sizeof(struct ext4_dir_entry_tail)));
 	while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize))
-		d = (struct ext4_dir_entry *)(((void *)d) +
+		d = (struct ext4_dir_entry_2 *)(((void *)d) +
 		    ext4_rec_len_from_disk(d->rec_len, blocksize));
 
 	if (d != top)
@@ -410,22 +410,22 @@ int ext4_handle_dirty_dirblock(handle_t *handle,
 }
 
 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
-					       struct ext4_dir_entry *dirent,
+					       struct ext4_dir_entry_2 *dirent,
 					       int *offset)
 {
-	struct ext4_dir_entry *dp;
+	struct ext4_dir_entry_2 *de;
 	struct dx_root_info *root;
 	int count_offset;
 	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
 	unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize);
 
 	if (rlen == blocksize)
-		count_offset = 8;
+		count_offset = sizeof(struct dx_node);
 	else if (rlen == 12) {
-		dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
-		if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 12)
+		de = (struct ext4_dir_entry_2 *)(((void *)dirent) + 12);
+		if (ext4_rec_len_from_disk(de->rec_len, blocksize) != blocksize - 12)
 			return NULL;
-		root = (struct dx_root_info *)(((void *)dp + 12));
+		root = (struct dx_root_info *)(((void *)de + 12));
 		if (root->reserved_zero ||
 		    root->info_length != sizeof(struct dx_root_info))
 			return NULL;
@@ -438,7 +438,7 @@ static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 	return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 }
 
-static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
+static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry_2 *dirent,
 			   int count_offset, int count, struct dx_tail *t)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
@@ -456,7 +456,7 @@ static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 }
 
 static int ext4_dx_csum_verify(struct inode *inode,
-			       struct ext4_dir_entry *dirent)
+			       struct ext4_dir_entry_2 *dirent)
 {
 	struct dx_countlimit *c;
 	struct dx_tail *t;
@@ -489,7 +489,7 @@ static int ext4_dx_csum_verify(struct inode *inode,
 	return 1;
 }
 
-static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
+static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry_2 *dirent)
 {
 	struct dx_countlimit *c;
 	struct dx_tail *t;
@@ -523,7 +523,7 @@ static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 					    struct inode *inode,
 					    struct buffer_head *bh)
 {
-	ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
+	ext4_dx_csum_set(inode, (struct ext4_dir_entry_2 *)bh->b_data);
 	return ext4_handle_dirty_metadata(handle, inode, bh);
 }
 
@@ -1496,7 +1496,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 }
 
 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
-			       struct ext4_dir_entry *de)
+			       struct ext4_dir_entry_2 *de)
 {
 	struct super_block *sb = dir->i_sb;
 
@@ -1627,7 +1627,7 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
 		}
 		if (!buffer_verified(bh) &&
 		    !is_dx_internal_node(dir, block,
-					 (struct ext4_dir_entry *)bh->b_data) &&
+					 (struct ext4_dir_entry_2 *)bh->b_data) &&
 		    !ext4_dirblock_csum_verify(dir, bh)) {
 			EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
 					     "checksumming directory "
-- 
2.43.7