Commit 83f90f21 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Tong Tiangen
Browse files

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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarSuren Baghdasaryan <surenb@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
parent 78c346ca

mm/memory.c

+3 −4
Original line number Diff line number Diff line
@@ -4603,10 +4603,9 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf) 
			return ret;

	}



	if (vmf->flags & FAULT_FLAG_VMA_LOCK) {

		vma_end_read(vmf->vma);

		return VM_FAULT_RETRY;

	}

	ret = vmf_can_call_fault(vmf);

	if (ret)

		return ret;



	ret = __do_fault(vmf);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))