Merge branch 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...

[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / file.c

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 72e73461c0643bbf128504c93a9c47dd377784aa..0f09526aa7d9d2017bb229eb4310f777c4b3b578 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1291,7 +1291,8 @@ out:
  * on error we return an unlocked page and the error value
  * on success we return a locked page and 0
  */
-static int prepare_uptodate_page(struct page *page, u64 pos,
+static int prepare_uptodate_page(struct inode *inode,
+                                struct page *page, u64 pos,
                                 bool force_uptodate)
 {
        int ret = 0;
@@ -1306,6 +1307,10 @@ static int prepare_uptodate_page(struct page *page, u64 pos,
                        unlock_page(page);
                        return -EIO;
                }
+               if (page->mapping != inode->i_mapping) {
+                       unlock_page(page);
+                       return -EAGAIN;
+               }
        }
        return 0;
 }
@@ -1324,6 +1329,7 @@ static noinline int prepare_pages(struct inode *inode, struct page **pages,
        int faili;
 
        for (i = 0; i < num_pages; i++) {
+again:
                pages[i] = find_or_create_page(inode->i_mapping, index + i,
                                               mask | __GFP_WRITE);
                if (!pages[i]) {
@@ -1333,13 +1339,17 @@ static noinline int prepare_pages(struct inode *inode, struct page **pages,
                }
 
                if (i == 0)
-                       err = prepare_uptodate_page(pages[i], pos,
+                       err = prepare_uptodate_page(inode, pages[i], pos,
                                                    force_uptodate);
-               if (i == num_pages - 1)
-                       err = prepare_uptodate_page(pages[i],
+               if (!err && i == num_pages - 1)
+                       err = prepare_uptodate_page(inode, pages[i],
                                                    pos + write_bytes, false);
                if (err) {
                        page_cache_release(pages[i]);
+                       if (err == -EAGAIN) {
+                               err = 0;
+                               goto again;
+                       }
                        faili = i - 1;
                        goto fail;
                }