1 files changed, 39 insertions, 28 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 55f68422061d..ee34497500e1 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -28,6 +28,7 @@
 #include "compression.h"
 #include "delalloc-space.h"
 #include "reflink.h"
+#include "subpage.h"
 
 static struct kmem_cache *btrfs_inode_defrag_cachep;
 /*
@@ -398,7 +399,7 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
 		/*
 		 * Copy data from userspace to the current page
 		 */
-		copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
+		copied = copy_page_from_iter_atomic(page, offset, count, i);
 
 		/* Flush processor's dcache for this page */
 		flush_dcache_page(page);
@@ -412,20 +413,19 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
 		 * The rest of the btrfs_file_write code will fall
 		 * back to page at a time copies after we return 0.
 		 */
-		if (!PageUptodate(page) && copied < count)
-			copied = 0;
+		if (unlikely(copied < count)) {
+			if (!PageUptodate(page)) {
+				iov_iter_revert(i, copied);
+				copied = 0;
+			}
+			if (!copied)
+				break;
+		}
 
-		iov_iter_advance(i, copied);
 		write_bytes -= copied;
 		total_copied += copied;
-
-		/* Return to btrfs_file_write_iter to fault page */
-		if (unlikely(copied == 0))
-			break;
-
-		if (copied < PAGE_SIZE - offset) {
-			offset += copied;
-		} else {
+		offset += copied;
+		if (offset == PAGE_SIZE) {
 			pg++;
 			offset = 0;
 		}
@@ -482,6 +482,7 @@ int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
 	start_pos = round_down(pos, fs_info->sectorsize);
 	num_bytes = round_up(write_bytes + pos - start_pos,
 			     fs_info->sectorsize);
+	ASSERT(num_bytes <= U32_MAX);
 
 	end_of_last_block = start_pos + num_bytes - 1;
 
@@ -500,9 +501,10 @@ int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
 
 	for (i = 0; i < num_pages; i++) {
 		struct page *p = pages[i];
-		SetPageUptodate(p);
+
+		btrfs_page_clamp_set_uptodate(fs_info, p, start_pos, num_bytes);
 		ClearPageChecked(p);
-		set_page_dirty(p);
+		btrfs_page_clamp_set_dirty(fs_info, p, start_pos, num_bytes);
 	}
 
 	/*
@@ -2483,6 +2485,17 @@ static int btrfs_punch_hole_lock_range(struct inode *inode,
 				       const u64 lockend,
 				       struct extent_state **cached_state)
 {
+	/*
+	 * For subpage case, if the range is not at page boundary, we could
+	 * have pages at the leading/tailing part of the range.
+	 * This could lead to dead loop since filemap_range_has_page()
+	 * will always return true.
+	 * So here we need to do extra page alignment for
+	 * filemap_range_has_page().
+	 */
+	const u64 page_lockstart = round_up(lockstart, PAGE_SIZE);
+	const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE) - 1;
+
 	while (1) {
 		struct btrfs_ordered_extent *ordered;
 		int ret;
@@ -2503,7 +2516,7 @@ static int btrfs_punch_hole_lock_range(struct inode *inode,
 		    (ordered->file_offset + ordered->num_bytes <= lockstart ||
 		     ordered->file_offset > lockend)) &&
 		     !filemap_range_has_page(inode->i_mapping,
-					     lockstart, lockend)) {
+					     page_lockstart, page_lockend)) {
 			if (ordered)
 				btrfs_put_ordered_extent(ordered);
 			break;
@@ -3034,22 +3047,20 @@ struct falloc_range {
  */
 static int add_falloc_range(struct list_head *head, u64 start, u64 len)
 {
-	struct falloc_range *prev = NULL;
 	struct falloc_range *range = NULL;
 
-	if (list_empty(head))
-		goto insert;
-
-	/*
-	 * As fallocate iterate by bytenr order, we only need to check
-	 * the last range.
-	 */
-	prev = list_entry(head->prev, struct falloc_range, list);
-	if (prev->start + prev->len == start) {
-		prev->len += len;
-		return 0;
+	if (!list_empty(head)) {
+		/*
+		 * As fallocate iterates by bytenr order, we only need to check
+		 * the last range.
+		 */
+		range = list_last_entry(head, struct falloc_range, list);
+		if (range->start + range->len == start) {
+			range->len += len;
+			return 0;
+		}
 	}
-insert:
+
 	range = kmalloc(sizeof(*range), GFP_KERNEL);
 	if (!range)
 		return -ENOMEM;