direct-io: clean up error paths of do_blockdev_direct_IO

In preparation to resort DIO checks, reduce code duplication of error
handling in do_blockdev_direct_IO.

Link: https://lore.kernel.org/r/20201008062620.2928326-2-krisman@collabora.com
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 1832998..6c11db1 100644 (file)
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1170,7 +1170,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
                        blkbits = blksize_bits(bdev_logical_block_size(bdev));
                blocksize_mask = (1 << blkbits) - 1;
                if (align & blocksize_mask)
-                       goto out;
+                       return -EINVAL;
        }
 
        /* watch out for a 0 len io from a tricksy fs */
@@ -1178,9 +1178,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
                return 0;
 
        dio = kmem_cache_alloc(dio_cache, GFP_KERNEL);
-       retval = -ENOMEM;
        if (!dio)
-               goto out;
+               return -ENOMEM;
        /*
         * Believe it or not, zeroing out the page array caused a .5%
         * performance regression in a database benchmark.  So, we take
@@ -1199,22 +1198,16 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 
                        retval = filemap_write_and_wait_range(mapping, offset,
                                                              end - 1);
-                       if (retval) {
-                               inode_unlock(inode);
-                               kmem_cache_free(dio_cache, dio);
-                               goto out;
-                       }
+                       if (retval)
+                               goto fail_dio;
                }
        }
 
        /* Once we sampled i_size check for reads beyond EOF */
        dio->i_size = i_size_read(inode);
        if (iov_iter_rw(iter) == READ && offset >= dio->i_size) {
-               if (dio->flags & DIO_LOCKING)
-                       inode_unlock(inode);
-               kmem_cache_free(dio_cache, dio);
                retval = 0;
-               goto out;
+               goto fail_dio;
        }
 
        /*
@@ -1258,14 +1251,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
                         */
                        retval = sb_init_dio_done_wq(dio->inode->i_sb);
                }
-               if (retval) {
-                       /*
-                        * We grab i_mutex only for reads so we don't have
-                        * to release it here
-                        */
-                       kmem_cache_free(dio_cache, dio);
-                       goto out;
-               }
+               if (retval)
+                       goto fail_dio;
        }
 
        /*
@@ -1368,7 +1355,13 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
        } else
                BUG_ON(retval != -EIOCBQUEUED);
 
-out:
+       return retval;
+
+fail_dio:
+       if (dio->flags & DIO_LOCKING && iov_iter_rw(iter) == READ)
+               inode_unlock(inode);
+
+       kmem_cache_free(dio_cache, dio);
        return retval;
 }