Commit 528ee697 authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: put initial index value of a directory in a constant 



At btrfs_set_inode_index_count() we refer twice to the number 2 as the
initial index value for a directory (when it's empty), with a proper
comment explaining the reason for that value. In the next patch I'll
have to use that magic value in the directory logging code, so put
the value in a #define at btrfs_inode.h, to avoid hardcoding the
magic value again at tree-log.c.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent a450a4af

fs/btrfs/btrfs_inode.h

+10 −2
Original line number Diff line number Diff line
@@ -13,6 +13,13 @@ 
#include "ordered-data.h"

#include "delayed-inode.h"



/*

 * Since we search a directory based on f_pos (struct dir_context::pos) we have

 * to start at 2 since '.' and '..' have f_pos of 0 and 1 respectively, so

 * everybody else has to start at 2 (see btrfs_real_readdir() and dir_emit_dots()).

 */

#define BTRFS_DIR_START_INDEX 2



/*

 * ordered_data_close is set by truncate when a file that used

 * to have good data has been truncated to zero.  When it is set
@@ -173,8 +180,9 @@ struct btrfs_inode { 
	u64 disk_i_size;



	/*

	 * if this is a directory then index_cnt is the counter for the index

	 * number for new files that are created

	 * If this is a directory then index_cnt is the counter for the index

	 * number for new files that are created. For an empty directory, this

	 * must be initialized to BTRFS_DIR_START_INDEX.

	 */

	u64 index_cnt;

fs/btrfs/inode.c

+2 −8
Original line number Diff line number Diff line
@@ -5971,14 +5971,8 @@ static int btrfs_set_inode_index_count(struct btrfs_inode *inode) 
		goto out;

	ret = 0;



	/*

	 * MAGIC NUMBER EXPLANATION:

	 * since we search a directory based on f_pos we have to start at 2

	 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody

	 * else has to start at 2

	 */

	if (path->slots[0] == 0) {

		inode->index_cnt = 2;

		inode->index_cnt = BTRFS_DIR_START_INDEX;

		goto out;

	}
@@ -5989,7 +5983,7 @@ static int btrfs_set_inode_index_count(struct btrfs_inode *inode) 


	if (found_key.objectid != btrfs_ino(inode) ||

	    found_key.type != BTRFS_DIR_INDEX_KEY) {

		inode->index_cnt = 2;

		inode->index_cnt = BTRFS_DIR_START_INDEX;

		goto out;

	}