From: Ming Lei Date: Wed, 23 Oct 2013 13:44:53 +0000 (+0800) Subject: sysfs: fix sysfs_write_file for bin file X-Git-Tag: KARO-TX6-2013-11-08~27 X-Git-Url: https://git.karo-electronics.de/?p=karo-tx-linux.git;a=commitdiff_plain;h=a0a4cbb171c223d60e080792b2e1e34dd529423e sysfs: fix sysfs_write_file for bin file 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 --- diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 5d818df7250b..c3795978b404 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);