@@ -372,7 +372,14 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh);
void wb_update_bandwidth(struct bdi_writeback *wb);
+
+/* Invoke balance dirty pages in async mode. */
+#define BDP_ASYNC 0x0001
+
void balance_dirty_pages_ratelimited(struct address_space *mapping);
+int balance_dirty_pages_ratelimited_flags(struct address_space *mapping,
+ unsigned int flags);
+
bool wb_over_bg_thresh(struct bdi_writeback *wb);
typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
@@ -1545,8 +1545,8 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
* If we're over `background_thresh' then the writeback threads are woken to
* perform some writeout.
*/
-static void balance_dirty_pages(struct bdi_writeback *wb,
- unsigned long pages_dirtied)
+static int balance_dirty_pages(struct bdi_writeback *wb,
+ unsigned long pages_dirtied, unsigned int flags)
{
struct dirty_throttle_control gdtc_stor = { GDTC_INIT(wb) };
struct dirty_throttle_control mdtc_stor = { MDTC_INIT(wb, &gdtc_stor) };
@@ -1566,6 +1566,7 @@ static void balance_dirty_pages(struct bdi_writeback *wb,
struct backing_dev_info *bdi = wb->bdi;
bool strictlimit = bdi->capabilities & BDI_CAP_STRICTLIMIT;
unsigned long start_time = jiffies;
+ int ret = 0;
for (;;) {
unsigned long now = jiffies;
@@ -1794,6 +1795,10 @@ static void balance_dirty_pages(struct bdi_writeback *wb,
period,
pause,
start_time);
+ if (flags & BDP_ASYNC) {
+ ret = -EAGAIN;
+ break;
+ }
__set_current_state(TASK_KILLABLE);
wb->dirty_sleep = now;
io_schedule_timeout(pause);
@@ -1825,6 +1830,7 @@ static void balance_dirty_pages(struct bdi_writeback *wb,
if (fatal_signal_pending(current))
break;
}
+ return ret;
}
static DEFINE_PER_CPU(int, bdp_ratelimits);
@@ -1845,28 +1851,18 @@ static DEFINE_PER_CPU(int, bdp_ratelimits);
*/
DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
-/**
- * balance_dirty_pages_ratelimited - balance dirty memory state
- * @mapping: address_space which was dirtied
- *
- * Processes which are dirtying memory should call in here once for each page
- * which was newly dirtied. The function will periodically check the system's
- * dirty state and will initiate writeback if needed.
- *
- * Once we're over the dirty memory limit we decrease the ratelimiting
- * by a lot, to prevent individual processes from overshooting the limit
- * by (ratelimit_pages) each.
- */
-void balance_dirty_pages_ratelimited(struct address_space *mapping)
+int balance_dirty_pages_ratelimited_flags(struct address_space *mapping,
+ unsigned int flags)
{
struct inode *inode = mapping->host;
struct backing_dev_info *bdi = inode_to_bdi(inode);
struct bdi_writeback *wb = NULL;
int ratelimit;
+ int ret = 0;
int *p;
if (!(bdi->capabilities & BDI_CAP_WRITEBACK))
- return;
+ return ret;
if (inode_cgwb_enabled(inode))
wb = wb_get_create_current(bdi, GFP_KERNEL);
@@ -1906,9 +1902,27 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping)
preempt_enable();
if (unlikely(current->nr_dirtied >= ratelimit))
- balance_dirty_pages(wb, current->nr_dirtied);
+ balance_dirty_pages(wb, current->nr_dirtied, flags);
wb_put(wb);
+ return ret;
+}
+
+/**
+ * balance_dirty_pages_ratelimited - balance dirty memory state
+ * @mapping: address_space which was dirtied
+ *
+ * Processes which are dirtying memory should call in here once for each page
+ * which was newly dirtied. The function will periodically check the system's
+ * dirty state and will initiate writeback if needed.
+ *
+ * Once we're over the dirty memory limit we decrease the ratelimiting
+ * by a lot, to prevent individual processes from overshooting the limit
+ * by (ratelimit_pages) each.
+ */
+void balance_dirty_pages_ratelimited(struct address_space *mapping)
+{
+ balance_dirty_pages_ratelimited_flags(mapping, 0);
}
EXPORT_SYMBOL(balance_dirty_pages_ratelimited);