Merge tag 'staging-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging/IIO updates from Greg KH:
 "Here is the big staging/iio driver pull request for 5.1-rc1.

  Lots of good IIO driver updates and cleanups in here as always.
  Combined with the removal of the xgifb driver, we have a net "loss" of
  over 9000 lines in the pull request, always a nice thing.

  As the outreachy application process is currently happening, there are
  loads of tiny checkpatch cleanup fixes all over the staging tree,
  which accounts for the majority of the fixups"

* tag 'staging-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (341 commits)
  staging: mt7621-dma: remove license boilerplate text
  staging: mt7621-dma: add SPDX GPL-2.0+ license identifier
  Staging: ks7010: Replace typecast to int
  Staging: vt6655: Align a static function declaration
  staging: speakup: fix line over 80 characters.
  staging: mt7621-eth: Remove license boilerplate text
  staging: mt7621-eth: Add SPDX license identifier
  staging: ks7010: removed custom Michael MIC implementation.
  staging: rtl8192e: Fix space and suspect issue
  Staging: vt6655: Modify comment style of SPDX License Identifier
  Staging: vt6655: Modify comment style for SPDX-License-Identifier
  Staging: vt6655: Align a function declaration
  Staging: vt6655: Alignment of function declaration
  staging: rtl8712: Fix indentation issue
  staging: wilc1000: fix incorrent type in initializer
  staging: rtl8188eu: remove unused P2P_PRIVATE_IOCTL_SET_LEN
  staging: rtl8188eu: remove unused enum P2P_PROTO_WK_ID
  staging: rtl8723bs: Remove duplicated include from drv_types.h
  Staging: vt6655: Alignment should match open parenthesis
  staging: erofs: fix mis-acted TAIL merging behavior
  ...

1 files changed, 46 insertions, 24 deletions

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 90a8a9f1ac7d..74d497d39c5a 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -75,6 +75,9 @@ struct ashmem_range {
 /* LRU list of unpinned pages, protected by ashmem_mutex */
 static LIST_HEAD(ashmem_lru_list);
 
+static atomic_t ashmem_shrink_inflight = ATOMIC_INIT(0);
+static DECLARE_WAIT_QUEUE_HEAD(ashmem_shrink_wait);
+
 /*
  * long lru_count - The count of pages on our LRU list.
  *
@@ -126,7 +129,8 @@ static inline bool page_range_in_range(struct ashmem_range *range,
 		page_range_subsumes_range(range, start, end);
 }
 
-static inline bool range_before_page(struct ashmem_range *range, size_t page)
+static inline bool range_before_page(struct ashmem_range *range,
+				     size_t page)
 {
 	return range->pgend < page;
 }
@@ -168,19 +172,15 @@ static inline void lru_del(struct ashmem_range *range)
  * @end:	   The ending page (inclusive)
  *
  * This function is protected by ashmem_mutex.
- *
- * Return: 0 if successful, or -ENOMEM if there is an error
  */
-static int range_alloc(struct ashmem_area *asma,
-		       struct ashmem_range *prev_range, unsigned int purged,
-		       size_t start, size_t end)
+static void range_alloc(struct ashmem_area *asma,
+			struct ashmem_range *prev_range, unsigned int purged,
+			size_t start, size_t end,
+			struct ashmem_range **new_range)
 {
-	struct ashmem_range *range;
-
-	range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL);
-	if (!range)
-		return -ENOMEM;
+	struct ashmem_range *range = *new_range;
 
+	*new_range = NULL;
 	range->asma = asma;
 	range->pgstart = start;
 	range->pgend = end;
@@ -190,8 +190,6 @@ static int range_alloc(struct ashmem_area *asma,
 
 	if (range_on_lru(range))
 		lru_add(range);
-
-	return 0;
 }
 
 /**
@@ -438,7 +436,6 @@ out:
 static unsigned long
 ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
-	struct ashmem_range *range, *next;
 	unsigned long freed = 0;
 
 	/* We might recurse into filesystem code, so bail out if necessary */
@@ -448,21 +445,33 @@ ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 	if (!mutex_trylock(&ashmem_mutex))
 		return -1;
 
-	list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) {
+	while (!list_empty(&ashmem_lru_list)) {
+		struct ashmem_range *range =
+			list_first_entry(&ashmem_lru_list, typeof(*range), lru);
 		loff_t start = range->pgstart * PAGE_SIZE;
 		loff_t end = (range->pgend + 1) * PAGE_SIZE;
+		struct file *f = range->asma->file;
 
-		range->asma->file->f_op->fallocate(range->asma->file,
-				FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-				start, end - start);
+		get_file(f);
+		atomic_inc(&ashmem_shrink_inflight);
 		range->purged = ASHMEM_WAS_PURGED;
 		lru_del(range);
 
 		freed += range_size(range);
+		mutex_unlock(&ashmem_mutex);
+		f->f_op->fallocate(f,
+				   FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+				   start, end - start);
+		fput(f);
+		if (atomic_dec_and_test(&ashmem_shrink_inflight))
+			wake_up_all(&ashmem_shrink_wait);
+		if (!mutex_trylock(&ashmem_mutex))
+			goto out;
 		if (--sc->nr_to_scan <= 0)
 			break;
 	}
 	mutex_unlock(&ashmem_mutex);
+out:
 	return freed;
 }
 
@@ -582,7 +591,8 @@ static int get_name(struct ashmem_area *asma, void __user *name)
  *
  * Caller must hold ashmem_mutex.
  */
-static int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend)
+static int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend,
+		      struct ashmem_range **new_range)
 {
 	struct ashmem_range *range, *next;
 	int ret = ASHMEM_NOT_PURGED;
@@ -635,7 +645,7 @@ static int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend)
 			 * second half and adjust the first chunk's endpoint.
 			 */
 			range_alloc(asma, range, range->purged,
-				    pgend + 1, range->pgend);
+				    pgend + 1, range->pgend, new_range);
 			range_shrink(range, range->pgstart, pgstart - 1);
 			break;
 		}
@@ -649,7 +659,8 @@ static int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend)
  *
  * Caller must hold ashmem_mutex.
  */
-static int ashmem_unpin(struct ashmem_area *asma, size_t pgstart, size_t pgend)
+static int ashmem_unpin(struct ashmem_area *asma, size_t pgstart, size_t pgend,
+			struct ashmem_range **new_range)
 {
 	struct ashmem_range *range, *next;
 	unsigned int purged = ASHMEM_NOT_PURGED;
@@ -675,7 +686,8 @@ restart:
 		}
 	}
 
-	return range_alloc(asma, range, purged, pgstart, pgend);
+	range_alloc(asma, range, purged, pgstart, pgend, new_range);
+	return 0;
 }
 
 /*
@@ -708,11 +720,19 @@ static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd,
 	struct ashmem_pin pin;
 	size_t pgstart, pgend;
 	int ret = -EINVAL;
+	struct ashmem_range *range = NULL;
 
 	if (copy_from_user(&pin, p, sizeof(pin)))
 		return -EFAULT;
 
+	if (cmd == ASHMEM_PIN || cmd == ASHMEM_UNPIN) {
+		range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL);
+		if (!range)
+			return -ENOMEM;
+	}
+
 	mutex_lock(&ashmem_mutex);
+	wait_event(ashmem_shrink_wait, !atomic_read(&ashmem_shrink_inflight));
 
 	if (!asma->file)
 		goto out_unlock;
@@ -735,10 +755,10 @@ static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd,
 
 	switch (cmd) {
 	case ASHMEM_PIN:
-		ret = ashmem_pin(asma, pgstart, pgend);
+		ret = ashmem_pin(asma, pgstart, pgend, &range);
 		break;
 	case ASHMEM_UNPIN:
-		ret = ashmem_unpin(asma, pgstart, pgend);
+		ret = ashmem_unpin(asma, pgstart, pgend, &range);
 		break;
 	case ASHMEM_GET_PIN_STATUS:
 		ret = ashmem_get_pin_status(asma, pgstart, pgend);
@@ -747,6 +767,8 @@ static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd,
 
 out_unlock:
 	mutex_unlock(&ashmem_mutex);
+	if (range)
+		kmem_cache_free(ashmem_range_cachep, range);
 
 	return ret;
 }