After a direct I/O request covering an uninitalized extent (i.e.,
created using the fallocate system call) or a hole in a file, ext4
will convert the uninitialized extent so it is marked as initialized
by calling ext4_convert_unwritten_extents(). This function returns
zero on success.
This return value was getting returned by ext4_direct_IO(); however
the file system's direct_IO function is supposed to return the number
of bytes read or written on a success. By returning zero, it confused
the direct I/O code into falling back to buffered I/O unnecessarily.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
*
* This function is called from the direct IO end io call back
* function, to convert the fallocated extents after IO is completed.
+ * Returns 0 on success.
*/
int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
loff_t len)
if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
ext4_free_io_end(iocb->private);
iocb->private = NULL;
- } else if (ret > 0)
+ } else if (ret > 0) {
+ int err;
/*
* for non AIO case, since the IO is already
* completed, we could do the convertion right here
*/
- ret = ext4_convert_unwritten_extents(inode,
- offset, ret);
+ err = ext4_convert_unwritten_extents(inode,
+ offset, ret);
+ if (err < 0)
+ ret = err;
+ }
return ret;
}