On Wed, Dec 18, 2019 at 08:53:05AM -0800, Linus Torvalds wrote:
> On Wed, Dec 18, 2019 at 6:59 AM Jason Gunthorpe <jgg@xxxxxxxxxxxx> wrote:
> Yes, global function names need to be unique, and if they aren't
> really core, they want some prefix that explains the context, because
> global functions are called from _outside_ the context that explains
> them.
Yes, in this thread I have mostly talked about changing the global
struct names, and for that mmn_ is the context explaining prefix.
> But if it's a "struct mmu_interval_notifier" pointer, and it's inside
> a file that is all about these pointers, it shouldn't be called
> "mmn_xyz". That's not a name. That's line noise.
>
> So call it a "notifier". Maybe even an "interval_notifier" if you
> don't mind the typing. Name it by something _descriptive_. And if you
> want.
>
> And "subscriptions" is a lovely name. What does the "mmn" buy you?
To be clear, I was proposing this as the struct name:
'struct mmu_notifier_mm' becomes 'struct mmn_subscriptions'
(and similar for other mmu_notifier_x* and mmu_x_notifier patterns)
>From there we now have a natural and readable local variable name like
'subscriptions' within mm/mmu_notifier.c
I've just started looking at this in detail, but it seems sticking
with 'mmu_notifier_' as the global prefix will avoid a fair amount of
churn. So lets not try to shorten it to mmn_ as the global prefix.
> Just to clarify: the names I really hated were the local variable
> names (and the argument names) that were all entirely within the
> context of mm/mmu_notifier.c. Calling something "mmn_mm" is a random
> jumble of letters that looks more like you're humming than you're
> speaking.
Yes, I understood - I've approached trying to have good names for the
variables via having good names for their struct's.
Below is what I'm suggesting for the first patch. I am intending a
patch series to make the naming better across mmu_notifier.h, this
would be the first.
Next patches would probably replace 'mn' with 'list_sub' (struct
mmu_notifier_subscription) and 'mni' with 'range_sub' (struct
mmu_notifier_range_subscription).
Thus we have code working on a 'list_sub/range_sub' and storing it in
a 'subscriptions'.
I think this is what you are looking for?
>From c656d0862dedcc2f5f4beda129a2ac51c892be7e Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Date: Wed, 18 Dec 2019 13:40:35 -0400
Subject: [PATCH] mm/mmu_notifier: Rename struct mmu_notifier_mm to
mmu_notifier_subscriptions
The name mmu_notifier_mm implies that the thing is a mm_struct pointer,
and is difficult to abbreviate. The struct is actually holding the
interval tree and hlist containing the notifiers subscribed to a mm.
Use 'subscriptions' as the variable name for this struct instead of the
really terrible and misleading 'mmn_mm'.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
---
include/linux/mm_types.h | 2 +-
include/linux/mmu_notifier.h | 18 +-
kernel/fork.c | 4 +-
mm/debug.c | 4 +-
mm/mmu_notifier.c | 322 ++++++++++++++++++-----------------
5 files changed, 182 insertions(+), 168 deletions(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 270aa8fd2800b4..e87bb864bdb29a 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -490,7 +490,7 @@ struct mm_struct {
/* store ref to file /proc/<pid>/exe symlink points to */
struct file __rcu *exe_file;
#ifdef CONFIG_MMU_NOTIFIER
- struct mmu_notifier_mm *mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *notifier_subscriptions;
#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
pgtable_t pmd_huge_pte; /* protected by page_table_lock */
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 9e6caa8ecd1938..a302925fbc6177 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -8,7 +8,7 @@
#include <linux/srcu.h>
#include <linux/interval_tree.h>
-struct mmu_notifier_mm;
+struct mmu_notifier_subscriptions;
struct mmu_notifier;
struct mmu_notifier_range;
struct mmu_interval_notifier;
@@ -265,7 +265,7 @@ struct mmu_notifier_range {
static inline int mm_has_notifiers(struct mm_struct *mm)
{
- return unlikely(mm->mmu_notifier_mm);
+ return unlikely(mm->notifier_subscriptions);
}
struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
@@ -364,7 +364,7 @@ static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *mni,
return READ_ONCE(mni->invalidate_seq) != seq;
}
-extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
+extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
extern void __mmu_notifier_release(struct mm_struct *mm);
extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
unsigned long start,
@@ -480,15 +480,15 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
__mmu_notifier_invalidate_range(mm, start, end);
}
-static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
{
- mm->mmu_notifier_mm = NULL;
+ mm->notifier_subscriptions = NULL;
}
-static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_mm_destroy(mm);
+ __mmu_notifier_subscriptions_destroy(mm);
}
@@ -692,11 +692,11 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
{
}
-static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
{
}
-static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
{
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 2508a4f238a3f3..047865086cdf74 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -692,7 +692,7 @@ void __mmdrop(struct mm_struct *mm)
WARN_ON_ONCE(mm == current->active_mm);
mm_free_pgd(mm);
destroy_context(mm);
- mmu_notifier_mm_destroy(mm);
+ mmu_notifier_subscriptions_destroy(mm);
check_mm(mm);
put_user_ns(mm->user_ns);
free_mm(mm);
@@ -1025,7 +1025,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
mm_init_aio(mm);
mm_init_owner(mm, p);
RCU_INIT_POINTER(mm->exe_file, NULL);
- mmu_notifier_mm_init(mm);
+ mmu_notifier_subscriptions_init(mm);
init_tlb_flush_pending(mm);
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
mm->pmd_huge_pte = NULL;
diff --git a/mm/debug.c b/mm/debug.c
index 0461df1207cb09..74ee73cf7079a5 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -153,7 +153,7 @@ void dump_mm(const struct mm_struct *mm)
#endif
"exe_file %px\n"
#ifdef CONFIG_MMU_NOTIFIER
- "mmu_notifier_mm %px\n"
+ "notifier_subscriptions %px\n"
#endif
#ifdef CONFIG_NUMA_BALANCING
"numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
@@ -185,7 +185,7 @@ void dump_mm(const struct mm_struct *mm)
#endif
mm->exe_file,
#ifdef CONFIG_MMU_NOTIFIER
- mm->mmu_notifier_mm,
+ mm->notifier_subscriptions,
#endif
#ifdef CONFIG_NUMA_BALANCING
mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index f76ea05b1cb011..02de878964a787 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -29,12 +29,12 @@ struct lockdep_map __mmu_notifier_invalidate_range_start_map = {
#endif
/*
- * The mmu notifier_mm structure is allocated and installed in
- * mm->mmu_notifier_mm inside the mm_take_all_locks() protected
+ * The mmu_notifier_subscriptions structure is allocated and installed in
+ * mm->notifier_subscriptions inside the mm_take_all_locks() protected
* critical section and it's released only when mm_count reaches zero
* in mmdrop().
*/
-struct mmu_notifier_mm {
+struct mmu_notifier_subscriptions {
/* all mmu notifiers registered in this mm are queued in this list */
struct hlist_head list;
bool has_itree;
@@ -75,7 +75,7 @@ struct mmu_notifier_mm {
* - some range on the mm_struct is being invalidated
* - the itree is allowed to change
*
- * Operations on mmu_notifier_mm->invalidate_seq (under spinlock):
+ * Operations on notifier_subscriptions->invalidate_seq (under spinlock):
* seq |= 1 # Begin writing
* seq++ # Release the writing state
* seq & 1 # True if a writer exists
@@ -83,32 +83,33 @@ struct mmu_notifier_mm {
* The later state avoids some expensive work on inv_end in the common case of
* no mni monitoring the VA.
*/
-static bool mn_itree_is_invalidating(struct mmu_notifier_mm *mmn_mm)
+static bool
+mn_itree_is_invalidating(struct mmu_notifier_subscriptions *subscriptions)
{
- lockdep_assert_held(&mmn_mm->lock);
- return mmn_mm->invalidate_seq & 1;
+ lockdep_assert_held(&subscriptions->lock);
+ return subscriptions->invalidate_seq & 1;
}
static struct mmu_interval_notifier *
-mn_itree_inv_start_range(struct mmu_notifier_mm *mmn_mm,
+mn_itree_inv_start_range(struct mmu_notifier_subscriptions *subscriptions,
const struct mmu_notifier_range *range,
unsigned long *seq)
{
struct interval_tree_node *node;
struct mmu_interval_notifier *res = NULL;
- spin_lock(&mmn_mm->lock);
- mmn_mm->active_invalidate_ranges++;
- node = interval_tree_iter_first(&mmn_mm->itree, range->start,
+ spin_lock(&subscriptions->lock);
+ subscriptions->active_invalidate_ranges++;
+ node = interval_tree_iter_first(&subscriptions->itree, range->start,
range->end - 1);
if (node) {
- mmn_mm->invalidate_seq |= 1;
+ subscriptions->invalidate_seq |= 1;
res = container_of(node, struct mmu_interval_notifier,
interval_tree);
}
- *seq = mmn_mm->invalidate_seq;
- spin_unlock(&mmn_mm->lock);
+ *seq = subscriptions->invalidate_seq;
+ spin_unlock(&subscriptions->lock);
return res;
}
@@ -125,20 +126,20 @@ mn_itree_inv_next(struct mmu_interval_notifier *mni,
return container_of(node, struct mmu_interval_notifier, interval_tree);
}
-static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
+static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
{
struct mmu_interval_notifier *mni;
struct hlist_node *next;
- spin_lock(&mmn_mm->lock);
- if (--mmn_mm->active_invalidate_ranges ||
- !mn_itree_is_invalidating(mmn_mm)) {
- spin_unlock(&mmn_mm->lock);
+ spin_lock(&subscriptions->lock);
+ if (--subscriptions->active_invalidate_ranges ||
+ !mn_itree_is_invalidating(subscriptions)) {
+ spin_unlock(&subscriptions->lock);
return;
}
/* Make invalidate_seq even */
- mmn_mm->invalidate_seq++;
+ subscriptions->invalidate_seq++;
/*
* The inv_end incorporates a deferred mechanism like rtnl_unlock().
@@ -146,19 +147,19 @@ static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
* they are progressed. This arrangement for tree updates is used to
* avoid using a blocking lock during invalidate_range_start.
*/
- hlist_for_each_entry_safe(mni, next, &mmn_mm->deferred_list,
+ hlist_for_each_entry_safe(mni, next, &subscriptions->deferred_list,
deferred_item) {
if (RB_EMPTY_NODE(&mni->interval_tree.rb))
interval_tree_insert(&mni->interval_tree,
- &mmn_mm->itree);
+ &subscriptions->itree);
else
interval_tree_remove(&mni->interval_tree,
- &mmn_mm->itree);
+ &subscriptions->itree);
hlist_del(&mni->deferred_item);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
- wake_up_all(&mmn_mm->wq);
+ wake_up_all(&subscriptions->wq);
}
/**
@@ -182,7 +183,8 @@ static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
*/
unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
{
- struct mmu_notifier_mm *mmn_mm = mni->mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mni->mm->notifier_subscriptions;
unsigned long seq;
bool is_invalidating;
@@ -190,17 +192,18 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
* If the mni has a different seq value under the user_lock than we
* started with then it has collided.
*
- * If the mni currently has the same seq value as the mmn_mm seq, then
- * it is currently between invalidate_start/end and is colliding.
+ * If the mni currently has the same seq value as the subscriptions
+ * seq, then it is currently between invalidate_start/end and is
+ * colliding.
*
* The locking looks broadly like this:
* mn_tree_invalidate_start(): mmu_interval_read_begin():
* spin_lock
* seq = READ_ONCE(mni->invalidate_seq);
- * seq == mmn_mm->invalidate_seq
+ * seq == subs->invalidate_seq
* spin_unlock
* spin_lock
- * seq = ++mmn_mm->invalidate_seq
+ * seq = ++subscriptions->invalidate_seq
* spin_unlock
* op->invalidate_range():
* user_lock
@@ -212,7 +215,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
*
* mn_itree_inv_end():
* spin_lock
- * seq = ++mmn_mm->invalidate_seq
+ * seq = ++subscriptions->invalidate_seq
* spin_unlock
*
* user_lock
@@ -224,24 +227,24 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
* eventual mmu_interval_read_retry(), which provides a barrier via the
* user_lock.
*/
- spin_lock(&mmn_mm->lock);
+ spin_lock(&subscriptions->lock);
/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
seq = READ_ONCE(mni->invalidate_seq);
- is_invalidating = seq == mmn_mm->invalidate_seq;
- spin_unlock(&mmn_mm->lock);
+ is_invalidating = seq == subscriptions->invalidate_seq;
+ spin_unlock(&subscriptions->lock);
/*
* mni->invalidate_seq must always be set to an odd value via
* mmu_interval_set_seq() using the provided cur_seq from
* mn_itree_inv_start_range(). This ensures that if seq does wrap we
* will always clear the below sleep in some reasonable time as
- * mmn_mm->invalidate_seq is even in the idle state.
+ * subscriptions->invalidate_seq is even in the idle state.
*/
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
if (is_invalidating)
- wait_event(mmn_mm->wq,
- READ_ONCE(mmn_mm->invalidate_seq) != seq);
+ wait_event(subscriptions->wq,
+ READ_ONCE(subscriptions->invalidate_seq) != seq);
/*
* Notice that mmu_interval_read_retry() can already be true at this
@@ -253,7 +256,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
}
EXPORT_SYMBOL_GPL(mmu_interval_read_begin);
-static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
+static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions,
struct mm_struct *mm)
{
struct mmu_notifier_range range = {
@@ -267,13 +270,13 @@ static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
unsigned long cur_seq;
bool ret;
- for (mni = mn_itree_inv_start_range(mmn_mm, &range, &cur_seq); mni;
- mni = mn_itree_inv_next(mni, &range)) {
+ for (mni = mn_itree_inv_start_range(subscriptions, &range, &cur_seq);
+ mni; mni = mn_itree_inv_next(mni, &range)) {
ret = mni->ops->invalidate(mni, &range, cur_seq);
WARN_ON(!ret);
}
- mn_itree_inv_end(mmn_mm);
+ mn_itree_inv_end(subscriptions);
}
/*
@@ -283,12 +286,12 @@ static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
* in parallel despite there being no task using this mm any more,
* through the vmas outside of the exit_mmap context, such as with
* vmtruncate. This serializes against mmu_notifier_unregister with
- * the mmu_notifier_mm->lock in addition to SRCU and it serializes
- * against the other mmu notifiers with SRCU. struct mmu_notifier_mm
+ * the notifier_subscriptions->lock in addition to SRCU and it serializes
+ * against the other mmu notifiers with SRCU. struct mmu_notifier_subscriptions
* can't go away from under us as exit_mmap holds an mm_count pin
* itself.
*/
-static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
+static void mn_hlist_release(struct mmu_notifier_subscriptions *subscriptions,
struct mm_struct *mm)
{
struct mmu_notifier *mn;
@@ -299,7 +302,7 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
* ->release returns.
*/
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist)
+ hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist)
/*
* If ->release runs before mmu_notifier_unregister it must be
* handled, as it's the only way for the driver to flush all
@@ -309,9 +312,9 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
if (mn->ops->release)
mn->ops->release(mn, mm);
- spin_lock(&mmn_mm->lock);
- while (unlikely(!hlist_empty(&mmn_mm->list))) {
- mn = hlist_entry(mmn_mm->list.first, struct mmu_notifier,
+ spin_lock(&subscriptions->lock);
+ while (unlikely(!hlist_empty(&subscriptions->list))) {
+ mn = hlist_entry(subscriptions->list.first, struct mmu_notifier,
hlist);
/*
* We arrived before mmu_notifier_unregister so
@@ -321,7 +324,7 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
*/
hlist_del_init_rcu(&mn->hlist);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
srcu_read_unlock(&srcu, id);
/*
@@ -330,21 +333,22 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
* until the ->release method returns, if it was invoked by
* mmu_notifier_unregister.
*
- * The mmu_notifier_mm can't go away from under us because one mm_count
- * is held by exit_mmap.
+ * The notifier_subscriptions can't go away from under us because
+ * one mm_count is held by exit_mmap.
*/
synchronize_srcu(&srcu);
}
void __mmu_notifier_release(struct mm_struct *mm)
{
- struct mmu_notifier_mm *mmn_mm = mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mm->notifier_subscriptions;
- if (mmn_mm->has_itree)
- mn_itree_release(mmn_mm, mm);
+ if (subscriptions->has_itree)
+ mn_itree_release(subscriptions, mm);
- if (!hlist_empty(&mmn_mm->list))
- mn_hlist_release(mmn_mm, mm);
+ if (!hlist_empty(&subscriptions->list))
+ mn_hlist_release(subscriptions, mm);
}
/*
@@ -360,7 +364,7 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->clear_flush_young)
young |= mn->ops->clear_flush_young(mn, mm, start, end);
}
@@ -377,7 +381,7 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->clear_young)
young |= mn->ops->clear_young(mn, mm, start, end);
}
@@ -393,7 +397,7 @@ int __mmu_notifier_test_young(struct mm_struct *mm,
int young = 0, id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->test_young) {
young = mn->ops->test_young(mn, mm, address);
if (young)
@@ -412,21 +416,22 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list,
+ hlist) {
if (mn->ops->change_pte)
mn->ops->change_pte(mn, mm, address, pte);
}
srcu_read_unlock(&srcu, id);
}
-static int mn_itree_invalidate(struct mmu_notifier_mm *mmn_mm,
+static int mn_itree_invalidate(struct mmu_notifier_subscriptions *subscriptions,
const struct mmu_notifier_range *range)
{
struct mmu_interval_notifier *mni;
unsigned long cur_seq;
- for (mni = mn_itree_inv_start_range(mmn_mm, range, &cur_seq); mni;
- mni = mn_itree_inv_next(mni, range)) {
+ for (mni = mn_itree_inv_start_range(subscriptions, range, &cur_seq);
+ mni; mni = mn_itree_inv_next(mni, range)) {
bool ret;
ret = mni->ops->invalidate(mni, range, cur_seq);
@@ -443,19 +448,20 @@ static int mn_itree_invalidate(struct mmu_notifier_mm *mmn_mm,
* On -EAGAIN the non-blocking caller is not allowed to call
* invalidate_range_end()
*/
- mn_itree_inv_end(mmn_mm);
+ mn_itree_inv_end(subscriptions);
return -EAGAIN;
}
-static int mn_hlist_invalidate_range_start(struct mmu_notifier_mm *mmn_mm,
- struct mmu_notifier_range *range)
+static int mn_hlist_invalidate_range_start(
+ struct mmu_notifier_subscriptions *subscriptions,
+ struct mmu_notifier_range *range)
{
struct mmu_notifier *mn;
int ret = 0;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) {
if (mn->ops->invalidate_range_start) {
int _ret;
@@ -481,28 +487,29 @@ static int mn_hlist_invalidate_range_start(struct mmu_notifier_mm *mmn_mm,
int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
{
- struct mmu_notifier_mm *mmn_mm = range->mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ range->mm->notifier_subscriptions;
int ret;
- if (mmn_mm->has_itree) {
- ret = mn_itree_invalidate(mmn_mm, range);
+ if (subscriptions->has_itree) {
+ ret = mn_itree_invalidate(subscriptions, range);
if (ret)
return ret;
}
- if (!hlist_empty(&mmn_mm->list))
- return mn_hlist_invalidate_range_start(mmn_mm, range);
+ if (!hlist_empty(&subscriptions->list))
+ return mn_hlist_invalidate_range_start(subscriptions, range);
return 0;
}
-static void mn_hlist_invalidate_end(struct mmu_notifier_mm *mmn_mm,
- struct mmu_notifier_range *range,
- bool only_end)
+static void
+mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
+ struct mmu_notifier_range *range, bool only_end)
{
struct mmu_notifier *mn;
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) {
/*
* Call invalidate_range here too to avoid the need for the
* subsystem of having to register an invalidate_range_end
@@ -534,14 +541,15 @@ static void mn_hlist_invalidate_end(struct mmu_notifier_mm *mmn_mm,
void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range,
bool only_end)
{
- struct mmu_notifier_mm *mmn_mm = range->mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ range->mm->notifier_subscriptions;
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
- if (mmn_mm->has_itree)
- mn_itree_inv_end(mmn_mm);
+ if (subscriptions->has_itree)
+ mn_itree_inv_end(subscriptions);
- if (!hlist_empty(&mmn_mm->list))
- mn_hlist_invalidate_end(mmn_mm, range, only_end);
+ if (!hlist_empty(&subscriptions->list))
+ mn_hlist_invalidate_end(subscriptions, range, only_end);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
}
@@ -552,7 +560,7 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm,
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) {
if (mn->ops->invalidate_range)
mn->ops->invalidate_range(mn, mm, start, end);
}
@@ -566,7 +574,7 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm,
*/
int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
{
- struct mmu_notifier_mm *mmu_notifier_mm = NULL;
+ struct mmu_notifier_subscriptions *subscriptions = NULL;
int ret;
lockdep_assert_held_write(&mm->mmap_sem);
@@ -579,23 +587,23 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
fs_reclaim_release(GFP_KERNEL);
}
- if (!mm->mmu_notifier_mm) {
+ if (!mm->notifier_subscriptions) {
/*
* kmalloc cannot be called under mm_take_all_locks(), but we
- * know that mm->mmu_notifier_mm can't change while we hold
- * the write side of the mmap_sem.
+ * know that mm->notifier_subscriptions can't change while we
+ * hold the write side of the mmap_sem.
*/
- mmu_notifier_mm =
- kzalloc(sizeof(struct mmu_notifier_mm), GFP_KERNEL);
- if (!mmu_notifier_mm)
+ subscriptions = kzalloc(
+ sizeof(struct mmu_notifier_subscriptions), GFP_KERNEL);
+ if (!subscriptions)
return -ENOMEM;
- INIT_HLIST_HEAD(&mmu_notifier_mm->list);
- spin_lock_init(&mmu_notifier_mm->lock);
- mmu_notifier_mm->invalidate_seq = 2;
- mmu_notifier_mm->itree = RB_ROOT_CACHED;
- init_waitqueue_head(&mmu_notifier_mm->wq);
- INIT_HLIST_HEAD(&mmu_notifier_mm->deferred_list);
+ INIT_HLIST_HEAD(&subscriptions->list);
+ spin_lock_init(&subscriptions->lock);
+ subscriptions->invalidate_seq = 2;
+ subscriptions->itree = RB_ROOT_CACHED;
+ init_waitqueue_head(&subscriptions->wq);
+ INIT_HLIST_HEAD(&subscriptions->deferred_list);
}
ret = mm_take_all_locks(mm);
@@ -610,15 +618,16 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
* We can't race against any other mmu notifier method either
* thanks to mm_take_all_locks().
*
- * release semantics on the initialization of the mmu_notifier_mm's
- * contents are provided for unlocked readers. acquire can only be
- * used while holding the mmgrab or mmget, and is safe because once
- * created the mmu_notififer_mm is not freed until the mm is
- * destroyed. As above, users holding the mmap_sem or one of the
+ * release semantics on the initialization of the
+ * mmu_notifier_subscriptions's contents are provided for unlocked
+ * readers. acquire can only be used while holding the mmgrab or
+ * mmget, and is safe because once created the
+ * mmu_notifier_subscriptions is not freed until the mm is destroyed.
+ * As above, users holding the mmap_sem or one of the
* mm_take_all_locks() do not need to use acquire semantics.
*/
- if (mmu_notifier_mm)
- smp_store_release(&mm->mmu_notifier_mm, mmu_notifier_mm);
+ if (subscriptions)
+ smp_store_release(&mm->notifier_subscriptions, subscriptions);
if (mn) {
/* Pairs with the mmdrop in mmu_notifier_unregister_* */
@@ -626,18 +635,19 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm)
mn->mm = mm;
mn->users = 1;
- spin_lock(&mm->mmu_notifier_mm->lock);
- hlist_add_head_rcu(&mn->hlist, &mm->mmu_notifier_mm->list);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_lock(&mm->notifier_subscriptions->lock);
+ hlist_add_head_rcu(&mn->hlist,
+ &mm->notifier_subscriptions->list);
+ spin_unlock(&mm->notifier_subscriptions->lock);
} else
- mm->mmu_notifier_mm->has_itree = true;
+ mm->notifier_subscriptions->has_itree = true;
mm_drop_all_locks(mm);
BUG_ON(atomic_read(&mm->mm_users) <= 0);
return 0;
out_clean:
- kfree(mmu_notifier_mm);
+ kfree(subscriptions);
return ret;
}
EXPORT_SYMBOL_GPL(__mmu_notifier_register);
@@ -677,8 +687,9 @@ find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops)
{
struct mmu_notifier *mn;
- spin_lock(&mm->mmu_notifier_mm->lock);
- hlist_for_each_entry_rcu (mn, &mm->mmu_notifier_mm->list, hlist) {
+ spin_lock(&mm->notifier_subscriptions->lock);
+ hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list,
+ hlist) {
if (mn->ops != ops)
continue;
@@ -686,10 +697,10 @@ find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops)
mn->users++;
else
mn = ERR_PTR(-EOVERFLOW);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
return mn;
}
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
return NULL;
}
@@ -718,7 +729,7 @@ struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
lockdep_assert_held_write(&mm->mmap_sem);
- if (mm->mmu_notifier_mm) {
+ if (mm->notifier_subscriptions) {
mn = find_get_mmu_notifier(mm, ops);
if (mn)
return mn;
@@ -739,11 +750,11 @@ struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
EXPORT_SYMBOL_GPL(mmu_notifier_get_locked);
/* this is called after the last mmu_notifier_unregister() returned */
-void __mmu_notifier_mm_destroy(struct mm_struct *mm)
+void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
{
- BUG_ON(!hlist_empty(&mm->mmu_notifier_mm->list));
- kfree(mm->mmu_notifier_mm);
- mm->mmu_notifier_mm = LIST_POISON1; /* debug */
+ BUG_ON(!hlist_empty(&mm->notifier_subscriptions->list));
+ kfree(mm->notifier_subscriptions);
+ mm->notifier_subscriptions = LIST_POISON1; /* debug */
}
/*
@@ -776,13 +787,13 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
mn->ops->release(mn, mm);
srcu_read_unlock(&srcu, id);
- spin_lock(&mm->mmu_notifier_mm->lock);
+ spin_lock(&mm->notifier_subscriptions->lock);
/*
* Can not use list_del_rcu() since __mmu_notifier_release
* can delete it before we hold the lock.
*/
hlist_del_init_rcu(&mn->hlist);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
}
/*
@@ -833,23 +844,23 @@ void mmu_notifier_put(struct mmu_notifier *mn)
{
struct mm_struct *mm = mn->mm;
- spin_lock(&mm->mmu_notifier_mm->lock);
+ spin_lock(&mm->notifier_subscriptions->lock);
if (WARN_ON(!mn->users) || --mn->users)
goto out_unlock;
hlist_del_init_rcu(&mn->hlist);
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
call_srcu(&srcu, &mn->rcu, mmu_notifier_free_rcu);
return;
out_unlock:
- spin_unlock(&mm->mmu_notifier_mm->lock);
+ spin_unlock(&mm->notifier_subscriptions->lock);
}
EXPORT_SYMBOL_GPL(mmu_notifier_put);
static int __mmu_interval_notifier_insert(
struct mmu_interval_notifier *mni, struct mm_struct *mm,
- struct mmu_notifier_mm *mmn_mm, unsigned long start,
+ struct mmu_notifier_subscriptions *subscriptions, unsigned long start,
unsigned long length, const struct mmu_interval_notifier_ops *ops)
{
mni->mm = mm;
@@ -884,29 +895,30 @@ static int __mmu_interval_notifier_insert(
* In all cases the value for the mni->invalidate_seq should be
* odd, see mmu_interval_read_begin()
*/
- spin_lock(&mmn_mm->lock);
- if (mmn_mm->active_invalidate_ranges) {
- if (mn_itree_is_invalidating(mmn_mm))
+ spin_lock(&subscriptions->lock);
+ if (subscriptions->active_invalidate_ranges) {
+ if (mn_itree_is_invalidating(subscriptions))
hlist_add_head(&mni->deferred_item,
- &mmn_mm->deferred_list);
+ &subscriptions->deferred_list);
else {
- mmn_mm->invalidate_seq |= 1;
+ subscriptions->invalidate_seq |= 1;
interval_tree_insert(&mni->interval_tree,
- &mmn_mm->itree);
+ &subscriptions->itree);
}
- mni->invalidate_seq = mmn_mm->invalidate_seq;
+ mni->invalidate_seq = subscriptions->invalidate_seq;
} else {
- WARN_ON(mn_itree_is_invalidating(mmn_mm));
+ WARN_ON(mn_itree_is_invalidating(subscriptions));
/*
* The starting seq for a mni not under invalidation should be
* odd, not equal to the current invalidate_seq and
* invalidate_seq should not 'wrap' to the new seq any time
* soon.
*/
- mni->invalidate_seq = mmn_mm->invalidate_seq - 1;
- interval_tree_insert(&mni->interval_tree, &mmn_mm->itree);
+ mni->invalidate_seq = subscriptions->invalidate_seq - 1;
+ interval_tree_insert(&mni->interval_tree,
+ &subscriptions->itree);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
return 0;
}
@@ -930,20 +942,20 @@ int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
unsigned long length,
const struct mmu_interval_notifier_ops *ops)
{
- struct mmu_notifier_mm *mmn_mm;
+ struct mmu_notifier_subscriptions *subscriptions;
int ret;
might_lock(&mm->mmap_sem);
- mmn_mm = smp_load_acquire(&mm->mmu_notifier_mm);
- if (!mmn_mm || !mmn_mm->has_itree) {
+ subscriptions = smp_load_acquire(&mm->notifier_subscriptions);
+ if (!subscriptions || !subscriptions->has_itree) {
ret = mmu_notifier_register(NULL, mm);
if (ret)
return ret;
- mmn_mm = mm->mmu_notifier_mm;
+ subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, mmn_mm, start, length,
- ops);
+ return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
+ length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert);
@@ -952,20 +964,20 @@ int mmu_interval_notifier_insert_locked(
unsigned long start, unsigned long length,
const struct mmu_interval_notifier_ops *ops)
{
- struct mmu_notifier_mm *mmn_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mm->notifier_subscriptions;
int ret;
lockdep_assert_held_write(&mm->mmap_sem);
- mmn_mm = mm->mmu_notifier_mm;
- if (!mmn_mm || !mmn_mm->has_itree) {
+ if (!subscriptions || !subscriptions->has_itree) {
ret = __mmu_notifier_register(NULL, mm);
if (ret)
return ret;
- mmn_mm = mm->mmu_notifier_mm;
+ subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, mmn_mm, start, length,
- ops);
+ return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
+ length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
@@ -982,13 +994,14 @@ EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
{
struct mm_struct *mm = mni->mm;
- struct mmu_notifier_mm *mmn_mm = mm->mmu_notifier_mm;
+ struct mmu_notifier_subscriptions *subscriptions =
+ mm->notifier_subscriptions;
unsigned long seq = 0;
might_sleep();
- spin_lock(&mmn_mm->lock);
- if (mn_itree_is_invalidating(mmn_mm)) {
+ spin_lock(&subscriptions->lock);
+ if (mn_itree_is_invalidating(subscriptions)) {
/*
* remove is being called after insert put this on the
* deferred list, but before the deferred list was processed.
@@ -997,14 +1010,15 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
hlist_del(&mni->deferred_item);
} else {
hlist_add_head(&mni->deferred_item,
- &mmn_mm->deferred_list);
- seq = mmn_mm->invalidate_seq;
+ &subscriptions->deferred_list);
+ seq = subscriptions->invalidate_seq;
}
} else {
WARN_ON(RB_EMPTY_NODE(&mni->interval_tree.rb));
- interval_tree_remove(&mni->interval_tree, &mmn_mm->itree);
+ interval_tree_remove(&mni->interval_tree,
+ &subscriptions->itree);
}
- spin_unlock(&mmn_mm->lock);
+ spin_unlock(&subscriptions->lock);
/*
* The possible sleep on progress in the invalidation requires the
@@ -1013,8 +1027,8 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
if (seq)
- wait_event(mmn_mm->wq,
- READ_ONCE(mmn_mm->invalidate_seq) != seq);
+ wait_event(subscriptions->wq,
+ READ_ONCE(subscriptions->invalidate_seq) != seq);
/* pairs with mmgrab in mmu_interval_notifier_insert() */
mmdrop(mm);
--
2.24.1
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