Commit 817202d9 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
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f2fs: readahead multi pages of directory for performance 



We have no so such readahead mechanism in ->iterate() path as the one in
->read() path, it cause low performance when we read large directory.
This patch add readahead in f2fs_readdir() for better performance.

Signed-off-by: default avatarChao Yu <chao2.yu@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
parent 5c1f9927

fs/f2fs/dir.c

+6 −0
Original line number Diff line number Diff line
@@ -637,11 +637,17 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx) 
	struct f2fs_dentry_block *dentry_blk = NULL;

	struct f2fs_dir_entry *de = NULL;

	struct page *dentry_page = NULL;

	struct file_ra_state *ra = &file->f_ra;

	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);

	unsigned char d_type = DT_UNKNOWN;



	bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);



	/* readahead for multi pages of dir */

	if (npages - n > 1 && !ra_has_index(ra, n))

		page_cache_sync_readahead(inode->i_mapping, ra, file, n,

				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));



	for (; n < npages; n++) {

		dentry_page = get_lock_data_page(inode, n);

		if (IS_ERR(dentry_page))

fs/f2fs/f2fs.h

+2 −0
Original line number Diff line number Diff line
@@ -182,6 +182,8 @@ enum { 


#define F2FS_LINK_MAX		32000	/* maximum link count per file */



#define MAX_DIR_RA_PAGES	4	/* maximum ra pages of dir */



/* for in-memory extent cache entry */

#define F2FS_MIN_EXTENT_LEN	16	/* minimum extent length */