Merge remote-tracking branches 'spi/fix/bcm63xx', 'spi/fix/doc', 'spi/fix/mediatek...

[firefly-linux-kernel-4.4.55.git] / fs / btrfs / file.c

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 977e715f0bf21a4ea8908700cfe4207dee1fe95d..72e73461c0643bbf128504c93a9c47dd377784aa 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1882,8 +1882,13 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
        struct btrfs_log_ctx ctx;
        int ret = 0;
        bool full_sync = 0;
-       const u64 len = end - start + 1;
+       u64 len;
 
+       /*
+        * The range length can be represented by u64, we have to do the typecasts
+        * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
+        */
+       len = (u64)end - (u64)start + 1;
        trace_btrfs_sync_file(file, datasync);
 
        /*
@@ -2071,8 +2076,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
                        }
                }
                if (!full_sync) {
-                       ret = btrfs_wait_ordered_range(inode, start,
-                                                      end - start + 1);
+                       ret = btrfs_wait_ordered_range(inode, start, len);
                        if (ret) {
                                btrfs_end_transaction(trans, root);
                                goto out;