tree de5b6fec7caec530f0dd72c9394a1a7d0b6f9878
parent 1e8b33328a5407b447ff80953655a47014a6dcb9
author Linus Torvalds <torvalds@linux-foundation.org> 1354220820 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1354221524 -0800

direct-io: don't read inode->i_blkbits multiple times

Since directio can work on a raw block device, and the block size of the
device can change under it, we need to do the same thing that
fs/buffer.c now does: read the block size a single time, using
ACCESS_ONCE().

Reading it multiple times can get different results, which will then
confuse the code because it actually encodes the i_blksize in
relationship to the underlying logical blocksize.

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