f2fs: do not preallocate block unaligned to 4KB

Previously f2fs_preallocate_blocks() tries to allocate unaligned blocks.
In f2fs_write_begin(), however, prepare_write_begin() does not skip its
allocation due to (len != 4KB).
So, it needs locking node page twice unexpectedly.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

path: root/lockme.h

#ifndef LOCKME_H
#define LOCKME_H

#include <sys/mman.h>

#include "die.h"

static inline void xlockme(void)
{
	if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0)
		panic("Cannot lock pages!\n");
}

static inline void xunlockme(void)
{
	munlockall();
}

#endif /* LOCKME_H */