From fb51f97cc85e031277be1316b1e15b185c7965a3 Mon Sep 17 00:00:00 2001
From: Alessandro Rubini <rubini@gnudd.com>
Date: Mon, 29 Oct 2012 07:38:21 +0100
Subject: [PATCH] buffers/kmalloc: fix buffer-full check, as size may change
If the user changes the buffer size, this might make more space for a
sleeping writer. Similarly, the buffer may be fuller than the new
value after a change, so we check for ">= limit" and not "== limit".
This doesn't apply to the vmalloc buffer, that currently doesn't allow
a size change.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Federico Vaga <federico.vaga@gmail.com>
---
buffers/zio-buf-kmalloc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/buffers/zio-buf-kmalloc.c b/buffers/zio-buf-kmalloc.c
index ca952c3..52f50e7 100644
--- a/buffers/zio-buf-kmalloc.c
+++ b/buffers/zio-buf-kmalloc.c
@@ -48,6 +48,11 @@ static DEFINE_ZATTR_STD(ZBUF, zbk_std_zattr) = {
static int zbk_conf_set(struct device *dev, struct zio_attribute *zattr,
uint32_t usr_val)
{
+ struct zio_bi *bi = to_zio_bi(dev);
+
+ /* If somebody is sleeping for write and we increase the size... */
+ wake_up_interruptible(&bi->q);
+
return 0;
}
struct zio_sysfs_operations zbk_sysfs_ops = {
@@ -144,7 +149,7 @@ static int zbk_store_block(struct zio_bi *bi, struct zio_block *block)
/* add to the buffer instance or push to the trigger */
spin_lock(&bi->lock);
- if (zbki->nitem == bi->zattr_set.std_zattr[ZATTR_ZBUF_MAXLEN].value)
+ if (zbki->nitem >= bi->zattr_set.std_zattr[ZATTR_ZBUF_MAXLEN].value)
goto out_unlock;
list_add_tail(&item->list, &zbki->list);
if (!zbki->nitem) {
--
GitLab