From 769f52676756b8c5feb302d2d95af59577fc69ec Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Wed, 4 Aug 2021 21:35:01 -0700 Subject: [PATCH] configfs: restore the kernel v5.13 text attribute write behavior Instead of appending new text attribute data at the offset specified by the write() system call, only pass the newly written data to the .store() callback. Reported-by: Bodo Stroesser Tested-by: Bodo Stroesser Signed-off-by: Bart Van Assche Signed-off-by: Christoph Hellwig --- fs/configfs/file.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/fs/configfs/file.c b/fs/configfs/file.c index 5a0be9985bae..0ad32150611e 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -177,28 +177,22 @@ out: 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)