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authorMing Lei <ming.lei@canonical.com>2013-10-23 21:44:53 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-25 05:46:27 +0100
commitb9c0622516b73170fa9abffece3079920b78ed6f (patch)
tree1e106a616c8ca1fda0f316b6207ff3612762c143
parent0cba7de7f6cdcf84c9b75d29041c475aedeb45c9 (diff)
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 <LW@karo-electronics.de> Tested-by: Lothar Waßmann <LW@karo-electronics.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/sysfs/file.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 5d818df7250..c3795978b40 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);