1 files changed, 20 insertions, 3 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1a81cd66d63b..ac35ec58db55 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -37,9 +37,9 @@ static int ext4_release_file (struct inode * inode, struct file * filp)
         if ((filp->f_mode & FMODE_WRITE) &&
                         (atomic_read(&inode->i_writecount) == 1))
         {
-                mutex_lock(&EXT4_I(inode)->truncate_mutex);
+                down_write(&EXT4_I(inode)->i_data_sem);
                 ext4_discard_reservation(inode);
-                mutex_unlock(&EXT4_I(inode)->truncate_mutex);
+                up_write(&EXT4_I(inode)->i_data_sem);
         }
         if (is_dx(inode) && filp->private_data)
                 ext4_htree_free_dir_info(filp->private_data);
@@ -56,8 +56,25 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
         ssize_t ret;
         int err;
 
-        ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+        /*
+         * If we have encountered a bitmap-format file, the size limit
+         * is smaller than s_maxbytes, which is for extent-mapped files.
+         */
+
+        if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
+                struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+                size_t length = iov_length(iov, nr_segs);
 
+                if (pos > sbi->s_bitmap_maxbytes)
+                        return -EFBIG;
+
+                if (pos + length > sbi->s_bitmap_maxbytes) {
+                        nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
+                                              sbi->s_bitmap_maxbytes - pos);
+                }
+        }
+
+        ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
         /*
          * Skip flushing if there was an error, or if nothing was written.
          */