Commit 26cf46be authored May 13, 2011 by Linus Torvalds

vfs: micro-optimize acl_permission_check()



It's a hot function, and we're better off not mixing types in the mask
calculations.  The compiler just ends up mixing 16-bit and 32-bit
operations, for no good reason.

So do everything in 'unsigned int' rather than mixing 'unsigned int'
masking with a 'umode_t' (16-bit) mode variable.

This, together with the parent commit (47a150ed: "Cache user_ns in
struct cred") makes acl_permission_check() much nicer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 47a150ed

fs/namei.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -179,7 +179,7 @@ EXPORT_SYMBOL(putname);
		static int acl_permission_check(struct inode *inode, int mask, unsigned int flags,
		int (check_acl)(struct inode inode, int mask, unsigned int flags))
		{
		umode_t mode = inode->i_mode;
		unsigned int mode = inode->i_mode;

		mask &= MAY_READ \| MAY_WRITE \| MAY_EXEC;