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mm: unexport __get_user_pages_unlocked()

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Unexport the low-level __get_user_pages_unlocked() function and replaces
invocations with calls to more appropriate higher-level functions.

In hva_to_pfn_slow() we are able to replace __get_user_pages_unlocked()
with get_user_pages_unlocked() since we can now pass gup_flags.

In async_pf_execute() and process_vm_rw_single_vec() we need to pass
different tsk, mm arguments so get_user_pages_remote() is the sane
replacement in these cases (having added manual acquisition and release
of mmap_sem.)

Additionally get_user_pages_remote() reintroduces use of the FOLL_TOUCH
flag.  However, this flag was originally silently dropped by commit
1e9877902d ("mm/gup: Introduce get_user_pages_remote()"), so this
appears to have been unintentional and reintroducing it is therefore not
an issue.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20161027095141.2569-3-lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Lorenzo Stoakes
2016-12-14 15:06:55 -08:00
committed by Linus Torvalds
parent 5b56d49fc3
commit 8b7457ef9a
6 changed files with 25 additions and 21 deletions
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12
mm/process_vm_access.c
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@@ -88,7 +88,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
ssize_t rc = 0;
unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
/ sizeof(struct pages *);
unsigned int flags = FOLL_REMOTE;
unsigned int flags = 0;
/* Work out address and page range required */
if (len == 0)
@@ -100,15 +100,19 @@ static int process_vm_rw_single_vec(unsigned long addr,
while (!rc && nr_pages && iov_iter_count(iter)) {
int pages = min(nr_pages, max_pages_per_loop);
int locked = 1;
size_t bytes;
/*
* Get the pages we're interested in. We must
* add FOLL_REMOTE because task/mm might not
* access remotely because task/mm might not
* current/current->mm
*/
pages = __get_user_pages_unlocked(task, mm, pa, pages,
process_pages, flags);
down_read(&mm->mmap_sem);
pages = get_user_pages_remote(task, mm, pa, pages, flags,
process_pages, NULL, &locked);
if (locked)
up_read(&mm->mmap_sem);
if (pages <= 0)
return -EFAULT;