mmap locking API: rename mmap_sem to mmap_lock

Rename the mmap_sem field to mmap_lock.  Any new uses of this lock should
now go through the new mmap locking api.  The mmap_lock is still
implemented as a rwsem, though this could change in the future.

[akpm@linux-foundation.org: fix it for mm-gup-might_lock_readmmap_sem-in-get_user_pages_fast.patch]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
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: Laurent Dufour <ldufour@linux.ibm.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/20200520052908.204642-11-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index 245545b..e9ce969 100644 (file)
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -74,8 +74,8 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
        mask = ((((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)
                | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT));
 
-       /* mmap_sem is performance critical.... */
-       prefetchw(&mm->mmap_sem);
+       /* mmap_lock is performance critical.... */
+       prefetchw(&mm->mmap_lock);
 
        /*
         * If we're in an interrupt or have no user context, we must not take the fault..

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8e7e4c2..c23bcd0 100644 (file)
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1359,7 +1359,7 @@ dotraplinkage void
 do_page_fault(struct pt_regs *regs, unsigned long hw_error_code,
                unsigned long address)
 {
-       prefetchw(&current->mm->mmap_sem);
+       prefetchw(&current->mm->mmap_lock);
        /*
         * KVM has two types of events that are, logically, interrupts, but
         * are unfortunately delivered using the #PF vector.  These events are

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index dc9ef30..701f399 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -661,7 +661,7 @@ static int etnaviv_gem_userptr_get_pages(struct etnaviv_gem_object *etnaviv_obj)
        struct etnaviv_gem_userptr *userptr = &etnaviv_obj->userptr;
        int ret, pinned = 0, npages = etnaviv_obj->base.size >> PAGE_SHIFT;
 
-       might_lock_read(&current->mm->mmap_sem);
+       might_lock_read(&current->mm->mmap_lock);
 
        if (userptr->mm != current->mm)
                return -EPERM;

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index ef6d3af..b6639b3 100644 (file)
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -440,7 +440,7 @@ struct mm_struct {
                spinlock_t page_table_lock; /* Protects page tables and some
                                             * counters
                                             */
-               struct rw_semaphore mmap_sem;
+               struct rw_semaphore mmap_lock;
 
                struct list_head mmlist; /* List of maybe swapped mm's. These
                                          * are globally strung together off

diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
index 43ef914..0707671 100644 (file)
--- a/include/linux/mmap_lock.h
+++ b/include/linux/mmap_lock.h
@@ -4,67 +4,67 @@
 #include <linux/mmdebug.h>
 
 #define MMAP_LOCK_INITIALIZER(name) \
-       .mmap_sem = __RWSEM_INITIALIZER((name).mmap_sem),
+       .mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),
 
 static inline void mmap_init_lock(struct mm_struct *mm)
 {
-       init_rwsem(&mm->mmap_sem);
+       init_rwsem(&mm->mmap_lock);
 }
 
 static inline void mmap_write_lock(struct mm_struct *mm)
 {
-       down_write(&mm->mmap_sem);
+       down_write(&mm->mmap_lock);
 }
 
 static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
 {
-       down_write_nested(&mm->mmap_sem, subclass);
+       down_write_nested(&mm->mmap_lock, subclass);
 }
 
 static inline int mmap_write_lock_killable(struct mm_struct *mm)
 {
-       return down_write_killable(&mm->mmap_sem);
+       return down_write_killable(&mm->mmap_lock);
 }
 
 static inline bool mmap_write_trylock(struct mm_struct *mm)
 {
-       return down_write_trylock(&mm->mmap_sem) != 0;
+       return down_write_trylock(&mm->mmap_lock) != 0;
 }
 
 static inline void mmap_write_unlock(struct mm_struct *mm)
 {
-       up_write(&mm->mmap_sem);
+       up_write(&mm->mmap_lock);
 }
 
 static inline void mmap_write_downgrade(struct mm_struct *mm)
 {
-       downgrade_write(&mm->mmap_sem);
+       downgrade_write(&mm->mmap_lock);
 }
 
 static inline void mmap_read_lock(struct mm_struct *mm)
 {
-       down_read(&mm->mmap_sem);
+       down_read(&mm->mmap_lock);
 }
 
 static inline int mmap_read_lock_killable(struct mm_struct *mm)
 {
-       return down_read_killable(&mm->mmap_sem);
+       return down_read_killable(&mm->mmap_lock);
 }
 
 static inline bool mmap_read_trylock(struct mm_struct *mm)
 {
-       return down_read_trylock(&mm->mmap_sem) != 0;
+       return down_read_trylock(&mm->mmap_lock) != 0;
 }
 
 static inline void mmap_read_unlock(struct mm_struct *mm)
 {
-       up_read(&mm->mmap_sem);
+       up_read(&mm->mmap_lock);
 }
 
 static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
 {
-       if (down_read_trylock(&mm->mmap_sem)) {
-               rwsem_release(&mm->mmap_sem.dep_map, _RET_IP_);
+       if (down_read_trylock(&mm->mmap_lock)) {
+               rwsem_release(&mm->mmap_lock.dep_map, _RET_IP_);
                return true;
        }
        return false;
@@ -72,19 +72,19 @@ static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
 
 static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
 {
-       up_read_non_owner(&mm->mmap_sem);
+       up_read_non_owner(&mm->mmap_lock);
 }
 
 static inline void mmap_assert_locked(struct mm_struct *mm)
 {
-       lockdep_assert_held(&mm->mmap_sem);
-       VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);
+       lockdep_assert_held(&mm->mmap_lock);
+       VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
 }
 
 static inline void mmap_assert_write_locked(struct mm_struct *mm)
 {
-       lockdep_assert_held_write(&mm->mmap_sem);
-       VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);
+       lockdep_assert_held_write(&mm->mmap_lock);
+       VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
 }
 
 #endif /* _LINUX_MMAP_LOCK_H */

diff --git a/mm/gup.c b/mm/gup.c
index 279739f..762fb9f 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2750,7 +2750,7 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages,
                return -EINVAL;
 
        if (!(gup_flags & FOLL_FAST_ONLY))
-               might_lock_read(&current->mm->mmap_sem);
+               might_lock_read(&current->mm->mmap_lock);
 
        start = untagged_addr(start) & PAGE_MASK;
        addr = start;

diff --git a/mm/memory.c b/mm/memory.c
index 533293f..823982a 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4804,7 +4804,7 @@ void __might_fault(const char *file, int line)
        __might_sleep(file, line, 0);
 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP)
        if (current->mm)
-               might_lock_read(&current->mm->mmap_sem);
+               might_lock_read(&current->mm->mmap_lock);
 #endif
 }
 EXPORT_SYMBOL(__might_fault);

diff --git a/mm/mmap.c b/mm/mmap.c
index 7ed7cfc..a28778d 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3474,7 +3474,7 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma)
                 * The LSB of head.next can't change from under us
                 * because we hold the mm_all_locks_mutex.
                 */
-               down_write_nest_lock(&anon_vma->root->rwsem, &mm->mmap_sem);
+               down_write_nest_lock(&anon_vma->root->rwsem, &mm->mmap_lock);
                /*
                 * We can safely modify head.next after taking the
                 * anon_vma->root->rwsem. If some other vma in this mm shares
@@ -3504,7 +3504,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping)
                 */
                if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags))
                        BUG();
-               down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_sem);
+               down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_lock);
        }
 }
 

diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 24eb9d1..2f348b6 100644 (file)
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -983,7 +983,7 @@ int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
        struct mmu_notifier_subscriptions *subscriptions;
        int ret;
 
-       might_lock(&mm->mmap_sem);
+       might_lock(&mm->mmap_lock);
 
        subscriptions = smp_load_acquire(&mm->notifier_subscriptions);
        if (!subscriptions || !subscriptions->has_itree) {