mm: handle read faults under the VMA lock

mainline inclusion
from mainline-v6.7-rc1
commit 12214eba1992642eee5813a9cc9f626e5b2d1815
category: other
bugzilla: https://gitee.com/openeuler/kernel/issues/I8K7C7

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=12214eba1992642eee5813a9cc9f626e5b2d1815

--------------------------------

Most file-backed faults are already handled through ->map_pages(), but if
we need to do I/O we'll come this way.  Since filemap_fault() is now safe
to be called under the VMA lock, we can handle these faults under the VMA
lock now.

Link: https://lkml.kernel.org/r/20231006195318.4087158-6-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>