Add annotation to let us know more clearly about space utilization information of regular dentry and inline dentry.
Signed-off-by: Chao Yu <[email protected]> --- include/linux/f2fs_fs.h | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index 920408a..25c6324 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -417,15 +417,25 @@ typedef __le32 f2fs_hash_t; #define GET_DENTRY_SLOTS(x) ((x + F2FS_SLOT_LEN - 1) >> F2FS_SLOT_LEN_BITS) -/* the number of dentry in a block */ -#define NR_DENTRY_IN_BLOCK 214 - /* MAX level for dir lookup */ #define MAX_DIR_HASH_DEPTH 63 /* MAX buckets in one level of dir */ #define MAX_DIR_BUCKETS (1 << ((MAX_DIR_HASH_DEPTH / 2) - 1)) +/* + * space utilization of regular dentry and inline dentry + * regular dentry inline dentry + * bitmap 1 * 27 = 27 1 * 23 = 23 + * reserved 1 * 3 = 3 1 * 7 = 7 + * dentry 11 * 214 = 2354 11 * 182 = 2002 + * filename 8 * 214 = 1712 8 * 182 = 1456 + * total 4096 3488 + * + * Note: there are more reserved space in inline dentry than in regular + * dentry, when converting inline dentry we should handle this carefully. + */ +#define NR_DENTRY_IN_BLOCK 214 /* the number of dentry in a block */ #define SIZE_OF_DIR_ENTRY 11 /* by byte */ #define SIZE_OF_DENTRY_BITMAP ((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \ BITS_PER_BYTE) -- 2.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
