Merge tag 'regmap-3.4' into regmap-stride

regmap: Last minute bug fix for 3.4

This is a last minute bug fix that was only just noticed since the code
path that's being exercised here is one that is fairly rarely used.  The
changelog for the change itself is extremely clear and the code itself
is obvious to inspection so should be pretty safe.

Conflicts:
	drivers/base/regmap/regmap.c (overlap between the fix and stride code)

1 files changed, 22 insertions, 6 deletions

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 8742fd013a9..eef311a58a6 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -51,6 +51,23 @@
 
 #define MAP_PAGE_ENTRIES	(PAGE_SIZE / sizeof(sector_t) - 1)
 
+/*
+ * Number of free pages that are not high.
+ */
+static inline unsigned long low_free_pages(void)
+{
+	return nr_free_pages() - nr_free_highpages();
+}
+
+/*
+ * Number of pages required to be kept free while writing the image. Always
+ * half of all available low pages before the writing starts.
+ */
+static inline unsigned long reqd_free_pages(void)
+{
+	return low_free_pages() / 2;
+}
+
 struct swap_map_page {
 	sector_t entries[MAP_PAGE_ENTRIES];
 	sector_t next_swap;
@@ -72,7 +89,7 @@ struct swap_map_handle {
 	sector_t cur_swap;
 	sector_t first_sector;
 	unsigned int k;
-	unsigned long nr_free_pages, written;
+	unsigned long reqd_free_pages;
 	u32 crc32;
 };
 
@@ -316,8 +333,7 @@ static int get_swap_writer(struct swap_map_handle *handle)
 		goto err_rel;
 	}
 	handle->k = 0;
-	handle->nr_free_pages = nr_free_pages() >> 1;
-	handle->written = 0;
+	handle->reqd_free_pages = reqd_free_pages();
 	handle->first_sector = handle->cur_swap;
 	return 0;
 err_rel:
@@ -352,11 +368,11 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
 		handle->cur_swap = offset;
 		handle->k = 0;
 	}
-	if (bio_chain && ++handle->written > handle->nr_free_pages) {
+	if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
 		error = hib_wait_on_bio_chain(bio_chain);
 		if (error)
 			goto out;
-		handle->written = 0;
+		handle->reqd_free_pages = reqd_free_pages();
 	}
  out:
 	return error;
@@ -618,7 +634,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
 	 * Adjust number of free pages after all allocations have been done.
 	 * We don't want to run out of pages when writing.
 	 */
-	handle->nr_free_pages = nr_free_pages() >> 1;
+	handle->reqd_free_pages = reqd_free_pages();
 
 	/*
 	 * Start the CRC32 thread.