Implement ->proc_write_buf() so procfs copies in what is written before
it pins the entry. simple_transaction_get() was only used to get a copy
of what was written, so look at procfs' copy instead and drop the
transaction. A second write to the same file doesn't fail with -EBUSY
anymore. Writes larger than PAGE_SIZE - 1 bytes fail with -EINVAL from
procfs instead of -EFBIG from simple_transaction_get(), which refused a
few bytes less.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
fs/lockd/procfs.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/fs/lockd/procfs.c b/fs/lockd/procfs.c
index a01f08c8c2f3..47949bec7a09 100644
--- a/fs/lockd/procfs.c
+++ b/fs/lockd/procfs.c
@@ -18,21 +18,15 @@
* We only allow strings that start with 'Y', 'y', or '1'.
*/
static ssize_t
-nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
- loff_t *pos)
+nlm_end_grace_write(struct file *file, char *buf, size_t size, loff_t *pos)
{
- char *data;
struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
lockd_net_id);
if (size < 1)
return -EINVAL;
- data = simple_transaction_get(file, buf, size);
- if (IS_ERR(data))
- return PTR_ERR(data);
-
- switch(data[0]) {
+ switch(buf[0]) {
case 'Y':
case 'y':
case '1':@@ -61,10 +55,9 @@ nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
}
static const struct proc_ops lockd_end_grace_proc_ops = {
- .proc_write = nlm_end_grace_write,
+ .proc_write_buf = nlm_end_grace_write,
.proc_read = nlm_end_grace_read,
.proc_lseek = default_llseek,
- .proc_release = simple_transaction_release,
};
int __init
--
2.53.0