The patch titled
Subject: filemap-drop-the-mmap_sem-for-all-blocking-operations-fix
has been added to the -mm tree. Its filename is
filemap-drop-the-mmap_sem-for-all-blocking-operations-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/filemap-drop-the-mmap_sem-for-all-blocking-operations-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/filemap-drop-the-mmap_sem-for-all-blocking-operations-fix.patch
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------------------------------------------------------
From: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>
Subject: filemap-drop-the-mmap_sem-for-all-blocking-operations-fix
Here's a fixup for "filemap: drop the mmap_sem for all blocking operations".
do_sync_mmap_readahead() drops mmap_sem now, so by the time of
dereferencing vmf->vma for count_memcg_event_mm() the VMA can be gone.
Link: http://lkml.kernel.org/r/20181228235106.okk3oastsnpxusxs@kshutemo-mobl1
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/filemap.c~filemap-drop-the-mmap_sem-for-all-blocking-operations-fix
+++ a/mm/filemap.c
@@ -2553,10 +2553,10 @@ vm_fault_t filemap_fault(struct vm_fault
fpin = do_async_mmap_readahead(vmf, page);
} else if (!page) {
/* No page in the page cache at all */
- fpin = do_sync_mmap_readahead(vmf);
count_vm_event(PGMAJFAULT);
count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
ret = VM_FAULT_MAJOR;
+ fpin = do_sync_mmap_readahead(vmf);
retry_find:
page = pagecache_get_page(mapping, offset,
FGP_CREAT|FGP_FOR_MMAP,
_
Patches currently in -mm which might be from kirill@xxxxxxxxxxxxx are
filemap-drop-the-mmap_sem-for-all-blocking-operations-fix.patch
