tree 554d8cf7254eb58210e98f2a1053f531f68f024b
parent 9489e9dcae718d5fde988e4a684a0f55b5f94d17
author Linus Torvalds <torvalds@linux-foundation.org> 1354213303 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1354214840 -0800

fs/buffer.c: make block-size be per-page and protected by the page lock

This makes the buffer size handling be a per-page thing, which allows us
to not have to worry about locking too much when changing the buffer
size.  If a page doesn't have buffers, we still need to read the block
size from the inode, but we can do that with ACCESS_ONCE(), so that even
if the size is changing, we get a consistent value.

This doesn't convert all functions - many of the buffer functions are
used purely by filesystems, which in turn results in the buffer size
being fixed at mount-time.  So they don't have the same consistency
issues that the raw device access can have.

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