Commit 61bc24ac authored by Al Viro's avatar Al Viro
Browse files

make sure that DNAME_INLINE_LEN is a multiple of word size 



... calling the number of words DNAME_INLINE_WORDS.

The next step will be to have a structure to hold inline name arrays
(both in dentry and in name_snapshot) and use that to alias the
existing arrays of unsigned char there.  That will allow both
full-structure copies and convenient word-by-word accesses.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 40384c84

fs/dcache.c

+1 −3
Original line number Diff line number Diff line
@@ -2748,9 +2748,7 @@ static void swap_names(struct dentry *dentry, struct dentry *target) 
			/*

			 * Both are internal.

			 */

			unsigned int i;

			BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long)));

			for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) {

			for (int i = 0; i < DNAME_INLINE_WORDS; i++) {

				swap(((long *) &dentry->d_iname)[i],

				     ((long *) &target->d_iname)[i]);

			}

include/linux/dcache.h

+5 −3
Original line number Diff line number Diff line
@@ -68,15 +68,17 @@ extern const struct qstr dotdot_name; 
 * large memory footprint increase).

 */

#ifdef CONFIG_64BIT

# define DNAME_INLINE_LEN 40 /* 192 bytes */

# define DNAME_INLINE_WORDS 5 /* 192 bytes */

#else

# ifdef CONFIG_SMP

#  define DNAME_INLINE_LEN 36 /* 128 bytes */

#  define DNAME_INLINE_WORDS 9 /* 128 bytes */

# else

#  define DNAME_INLINE_LEN 44 /* 128 bytes */

#  define DNAME_INLINE_WORDS 11 /* 128 bytes */

# endif

#endif



#define DNAME_INLINE_LEN (DNAME_INLINE_WORDS*sizeof(unsigned long))



#define d_lock	d_lockref.lock



struct dentry {