1 files changed, 25 insertions, 56 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 170df856bdb9..0736a6a2e2f0 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -253,27 +253,6 @@ out:
 }
 
 /*
- * Kick the writeback threads then try to free up some ZONE_NORMAL memory.
- */
-static void free_more_memory(void)
-{
-	struct zoneref *z;
-	int nid;
-
-	wakeup_flusher_threads(1024, WB_REASON_FREE_MORE_MEM);
-	yield();
-
-	for_each_online_node(nid) {
-
-		z = first_zones_zonelist(node_zonelist(nid, GFP_NOFS),
-						gfp_zone(GFP_NOFS), NULL);
-		if (z->zone)
-			try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0,
-						GFP_NOFS, NULL);
-	}
-}
-
-/*
  * I/O completion handler for block_read_full_page() - pages
  * which come unlocked at the end of I/O.
  */
@@ -861,16 +840,19 @@ int remove_inode_buffers(struct inode *inode)
  * which may not fail from ordinary buffer allocations.
  */
 struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
-		int retry)
+		bool retry)
 {
 	struct buffer_head *bh, *head;
+	gfp_t gfp = GFP_NOFS;
 	long offset;
 
-try_again:
+	if (retry)
+		gfp |= __GFP_NOFAIL;
+
 	head = NULL;
 	offset = PAGE_SIZE;
 	while ((offset -= size) >= 0) {
-		bh = alloc_buffer_head(GFP_NOFS);
+		bh = alloc_buffer_head(gfp);
 		if (!bh)
 			goto no_grow;
 
@@ -896,23 +878,7 @@ no_grow:
 		} while (head);
 	}
 
-	/*
-	 * Return failure for non-async IO requests.  Async IO requests
-	 * are not allowed to fail, so we have to wait until buffer heads
-	 * become available.  But we don't want tasks sleeping with 
-	 * partially complete buffers, so all were released above.
-	 */
-	if (!retry)
-		return NULL;
-
-	/* We're _really_ low on memory. Now we just
-	 * wait for old buffer heads to become free due to
-	 * finishing IO.  Since this is an async request and
-	 * the reserve list is empty, we're sure there are 
-	 * async buffer heads in use.
-	 */
-	free_more_memory();
-	goto try_again;
+	return NULL;
 }
 EXPORT_SYMBOL_GPL(alloc_page_buffers);
 
@@ -1001,8 +967,6 @@ grow_dev_page(struct block_device *bdev, sector_t block,
 	gfp_mask |= __GFP_NOFAIL;
 
 	page = find_or_create_page(inode->i_mapping, index, gfp_mask);
-	if (!page)
-		return ret;
 
 	BUG_ON(!PageLocked(page));
 
@@ -1021,9 +985,7 @@ grow_dev_page(struct block_device *bdev, sector_t block,
 	/*
 	 * Allocate some buffers for this page
 	 */
-	bh = alloc_page_buffers(page, size, 0);
-	if (!bh)
-		goto failed;
+	bh = alloc_page_buffers(page, size, true);
 
 	/*
 	 * Link the page to the buffers and initialise them.  Take the
@@ -1103,8 +1065,6 @@ __getblk_slow(struct block_device *bdev, sector_t block,
 		ret = grow_buffers(bdev, block, size, gfp);
 		if (ret < 0)
 			return NULL;
-		if (ret == 0)
-			free_more_memory();
 	}
 }
 
@@ -1575,7 +1535,7 @@ void create_empty_buffers(struct page *page,
 {
 	struct buffer_head *bh, *head, *tail;
 
-	head = alloc_page_buffers(page, blocksize, 1);
+	head = alloc_page_buffers(page, blocksize, true);
 	bh = head;
 	do {
 		bh->b_state |= b_state;
@@ -1632,7 +1592,7 @@ void clean_bdev_aliases(struct block_device *bdev, sector_t block, sector_t len)
 	struct buffer_head *head;
 
 	end = (block + len - 1) >> (PAGE_SHIFT - bd_inode->i_blkbits);
-	pagevec_init(&pvec, 0);
+	pagevec_init(&pvec);
 	while (pagevec_lookup_range(&pvec, bd_mapping, &index, end)) {
 		count = pagevec_count(&pvec);
 		for (i = 0; i < count; i++) {
@@ -1692,7 +1652,8 @@ static struct buffer_head *create_page_buffers(struct page *page, struct inode *
 	BUG_ON(!PageLocked(page));
 
 	if (!page_has_buffers(page))
-		create_empty_buffers(page, 1 << ACCESS_ONCE(inode->i_blkbits), b_state);
+		create_empty_buffers(page, 1 << READ_ONCE(inode->i_blkbits),
+				     b_state);
 	return page_buffers(page);
 }
 
@@ -1978,8 +1939,8 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh,
 	case IOMAP_MAPPED:
 		if (offset >= i_size_read(inode))
 			set_buffer_new(bh);
-		bh->b_blocknr = (iomap->blkno >> (inode->i_blkbits - 9)) +
-				((offset - iomap->offset) >> inode->i_blkbits);
+		bh->b_blocknr = (iomap->addr + offset - iomap->offset) >>
+				inode->i_blkbits;
 		set_buffer_mapped(bh);
 		break;
 	}
@@ -2638,7 +2599,7 @@ int nobh_write_begin(struct address_space *mapping,
 	 * Be careful: the buffer linked list is a NULL terminated one, rather
 	 * than the circular one we're used to.
 	 */
-	head = alloc_page_buffers(page, blocksize, 0);
+	head = alloc_page_buffers(page, blocksize, false);
 	if (!head) {
 		ret = -ENOMEM;
 		goto out_release;
@@ -3055,8 +3016,16 @@ void guard_bio_eod(int op, struct bio *bio)
 	sector_t maxsector;
 	struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
 	unsigned truncated_bytes;
+	struct hd_struct *part;
+
+	rcu_read_lock();
+	part = __disk_get_part(bio->bi_disk, bio->bi_partno);
+	if (part)
+		maxsector = part_nr_sects_read(part);
+	else
+		maxsector = get_capacity(bio->bi_disk);
+	rcu_read_unlock();
 
-	maxsector = get_capacity(bio->bi_disk);
 	if (!maxsector)
 		return;
 
@@ -3545,7 +3514,7 @@ page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length,
 	if (length <= 0)
 		return -ENOENT;
 
-	pagevec_init(&pvec, 0);
+	pagevec_init(&pvec);
 
 	do {
 		unsigned nr_pages, i;