commit d8ed45c5dcd455fc5848d47f86883a1b872ac0d0
author Michel Lespinasse <walken@google.com> Mon Jun 08 21:33:25 2020 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Tue Jun 09 09:39:14 2020 -0700
tree f9270b32da5f3f7be73b086c99d3dfc29a13161a
parent 0adf65f53aae86aa86d8dccada02890545de8938

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/ipv4/tcp.c

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 15d47d5..1714fe2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1762,11 +1762,11 @@ static int tcp_zerocopy_receive(struct sock *sk,
 
 	sock_rps_record_flow(sk);
 
-	down_read(&current->mm->mmap_sem);
+	mmap_read_lock(current->mm);
 
 	vma = find_vma(current->mm, address);
 	if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops) {
-		up_read(&current->mm->mmap_sem);
+		mmap_read_unlock(current->mm);
 		return -EINVAL;
 	}
 	zc->length = min_t(unsigned long, zc->length, vma->vm_end - address);
@@ -1827,7 +1827,7 @@ static int tcp_zerocopy_receive(struct sock *sk,
 		frags++;
 	}
 out:
-	up_read(&current->mm->mmap_sem);
+	mmap_read_unlock(current->mm);
 	if (length) {
 		WRITE_ONCE(tp->copied_seq, seq);
 		tcp_rcv_space_adjust(sk);