configfs fix for Linux 5.14

- fix to revert to the historic write behavior (Bart Van Assche)
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Merge tag 'configfs-5.14' of git://git.infradead.org/users/hch/configfs

Pull configfs fix from Christoph Hellwig:

 - fix to revert to the historic write behavior (Bart Van Assche)

* tag 'configfs-5.14' of git://git.infradead.org/users/hch/configfs:
  configfs: restore the kernel v5.13 text attribute write behavior
This commit is contained in:
Linus Torvalds 2021-08-14 06:22:42 -10:00
commit 118516e212

View file

@ -177,28 +177,22 @@ static ssize_t configfs_bin_read_iter(struct kiocb *iocb, struct iov_iter *to)
return retval;
}
/* Fill [buffer, buffer + pos) with data coming from @from. */
static int fill_write_buffer(struct configfs_buffer *buffer, loff_t pos,
/* Fill @buffer with data coming from @from. */
static int fill_write_buffer(struct configfs_buffer *buffer,
struct iov_iter *from)
{
loff_t to_copy;
int copied;
u8 *to;
if (!buffer->page)
buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0);
if (!buffer->page)
return -ENOMEM;
to_copy = SIMPLE_ATTR_SIZE - 1 - pos;
if (to_copy <= 0)
return 0;
to = buffer->page + pos;
copied = copy_from_iter(to, to_copy, from);
copied = copy_from_iter(buffer->page, SIMPLE_ATTR_SIZE - 1, from);
buffer->needs_read_fill = 1;
/* if buf is assumed to contain a string, terminate it by \0,
* so e.g. sscanf() can scan the string easily */
to[copied] = 0;
buffer->page[copied] = 0;
return copied ? : -EFAULT;
}
@ -227,10 +221,10 @@ static ssize_t configfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct configfs_buffer *buffer = file->private_data;
ssize_t len;
int len;
mutex_lock(&buffer->mutex);
len = fill_write_buffer(buffer, iocb->ki_pos, from);
len = fill_write_buffer(buffer, from);
if (len > 0)
len = flush_write_buffer(file, buffer, len);
if (len > 0)