From b9c0622516b73170fa9abffece3079920b78ed6f Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 23 Oct 2013 21:44:53 +0800 Subject: [PATCH] sysfs: fix sysfs_write_file for bin file MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Before patch(sysfs: prepare path write for unified regular / bin file handling), when size of bin file is zero, writting still can continue, but this patch changes the behaviour. The worse thing is that firmware loader is broken by this patch, and user space application can't write to firmware bin file any more because both firmware loader and drivers can't know at advance how large the firmware file is and have to set its initialized size as zero. This patch fixes the problem and keeps behaviour of writting to bin as before. Reported-by: Lothar Waßmann Tested-by: Lothar Waßmann Acked-by: Tejun Heo Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 5d818df..c379597 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -275,11 +275,10 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf, { struct sysfs_open_file *of = sysfs_of(file); ssize_t len = min_t(size_t, count, PAGE_SIZE); + loff_t size = file_inode(file)->i_size; char *buf; - if (sysfs_is_bin(of->sd)) { - loff_t size = file_inode(file)->i_size; - + if (sysfs_is_bin(of->sd) && size) { if (size <= *ppos) return 0; len = min_t(ssize_t, len, size - *ppos); -- 2.7.4