Fix _fat_bmap() locking
Fix _fat_bmap() locking

On swapon() path, it has already i_mutex. So, this uses i_alloc_sem
instead of it.

Signed-off-by: OGAWA Hirofumi <1dd685eef08048be95744a1b104ca593a93cc914@mail.parknet.co.jp>
Reported-by: Laurent GUERBY <f1b010126f61b5c59e7d5eb42c5c68f6105c5914@guerby.net>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas