summaryrefslogtreecommitdiff
path: root/include/linux/backing-dev.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/backing-dev.h')
-rw-r--r--include/linux/backing-dev.h24
1 files changed, 22 insertions, 2 deletions
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 94c93c9c5f66..00371734995c 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -20,26 +20,46 @@ enum bdi_state {
BDI_unused, /* Available bits start here */
};
+typedef int (congested_fn)(void *, int);
+
struct backing_dev_info {
unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */
unsigned long state; /* Always use atomic bitops on this */
int memory_backed; /* Cannot clean pages with writepage */
+ congested_fn *congested_fn; /* Function pointer if device is md/dm */
+ void *congested_data; /* Pointer to aux data for congested func */
+ void (*unplug_io_fn)(struct backing_dev_info *);
+ void *unplug_io_data;
};
extern struct backing_dev_info default_backing_dev_info;
+void default_unplug_io_fn(struct backing_dev_info *bdi);
int writeback_acquire(struct backing_dev_info *bdi);
int writeback_in_progress(struct backing_dev_info *bdi);
void writeback_release(struct backing_dev_info *bdi);
+static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits)
+{
+ if (bdi->congested_fn)
+ return bdi->congested_fn(bdi->congested_data, bdi_bits);
+ return (bdi->state & bdi_bits);
+}
+
static inline int bdi_read_congested(struct backing_dev_info *bdi)
{
- return test_bit(BDI_read_congested, &bdi->state);
+ return bdi_congested(bdi, 1 << BDI_read_congested);
}
static inline int bdi_write_congested(struct backing_dev_info *bdi)
{
- return test_bit(BDI_write_congested, &bdi->state);
+ return bdi_congested(bdi, 1 << BDI_write_congested);
+}
+
+static inline int bdi_rw_congested(struct backing_dev_info *bdi)
+{
+ return bdi_congested(bdi, (1 << BDI_read_congested)|
+ (1 << BDI_write_congested));
}
#endif /* _LINUX_BACKING_DEV_H */