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authorTejun Heo <tj@kernel.org>2015-05-23 00:13:32 +0300
committerJens Axboe <axboe@fb.com>2015-06-02 17:33:34 +0300
commit66114cad64bf76a155fec1f0fff0de771cf909d5 (patch)
tree58d7b8646add87cb40973961757a1c3598f3ee4c /include/linux/backing-dev-defs.h
parent4610007142823307d930ac890d822633a05ce08c (diff)
downloadlinux-66114cad64bf76a155fec1f0fff0de771cf909d5.tar.xz
writeback: separate out include/linux/backing-dev-defs.h
With the planned cgroup writeback support, backing-dev related declarations will be more widely used across block and cgroup; unfortunately, including backing-dev.h from include/linux/blkdev.h makes cyclic include dependency quite likely. This patch separates out backing-dev-defs.h which only has the essential definitions and updates blkdev.h to include it. c files which need access to more backing-dev details now include backing-dev.h directly. This takes backing-dev.h off the common include dependency chain making it a lot easier to use it across block and cgroup. v2: fs/fat build failure fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/backing-dev-defs.h')
-rw-r--r--include/linux/backing-dev-defs.h106
1 files changed, 106 insertions, 0 deletions
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
new file mode 100644
index 000000000000..aa18c4bd43c1
--- /dev/null
+++ b/include/linux/backing-dev-defs.h
@@ -0,0 +1,106 @@
+#ifndef __LINUX_BACKING_DEV_DEFS_H
+#define __LINUX_BACKING_DEV_DEFS_H
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/percpu_counter.h>
+#include <linux/flex_proportions.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+
+struct page;
+struct device;
+struct dentry;
+
+/*
+ * Bits in bdi_writeback.state
+ */
+enum wb_state {
+ WB_async_congested, /* The async (write) queue is getting full */
+ WB_sync_congested, /* The sync queue is getting full */
+ WB_registered, /* bdi_register() was done */
+ WB_writeback_running, /* Writeback is in progress */
+};
+
+typedef int (congested_fn)(void *, int);
+
+enum wb_stat_item {
+ WB_RECLAIMABLE,
+ WB_WRITEBACK,
+ WB_DIRTIED,
+ WB_WRITTEN,
+ NR_WB_STAT_ITEMS
+};
+
+#define WB_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
+
+struct bdi_writeback {
+ struct backing_dev_info *bdi; /* our parent bdi */
+
+ unsigned long state; /* Always use atomic bitops on this */
+ unsigned long last_old_flush; /* last old data flush */
+
+ struct list_head b_dirty; /* dirty inodes */
+ struct list_head b_io; /* parked for writeback */
+ struct list_head b_more_io; /* parked for more writeback */
+ struct list_head b_dirty_time; /* time stamps are dirty */
+ spinlock_t list_lock; /* protects the b_* lists */
+
+ struct percpu_counter stat[NR_WB_STAT_ITEMS];
+
+ unsigned long bw_time_stamp; /* last time write bw is updated */
+ unsigned long dirtied_stamp;
+ unsigned long written_stamp; /* pages written at bw_time_stamp */
+ unsigned long write_bandwidth; /* the estimated write bandwidth */
+ unsigned long avg_write_bandwidth; /* further smoothed write bw */
+
+ /*
+ * The base dirty throttle rate, re-calculated on every 200ms.
+ * All the bdi tasks' dirty rate will be curbed under it.
+ * @dirty_ratelimit tracks the estimated @balanced_dirty_ratelimit
+ * in small steps and is much more smooth/stable than the latter.
+ */
+ unsigned long dirty_ratelimit;
+ unsigned long balanced_dirty_ratelimit;
+
+ struct fprop_local_percpu completions;
+ int dirty_exceeded;
+
+ spinlock_t work_lock; /* protects work_list & dwork scheduling */
+ struct list_head work_list;
+ struct delayed_work dwork; /* work item used for writeback */
+};
+
+struct backing_dev_info {
+ struct list_head bdi_list;
+ unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */
+ unsigned int capabilities; /* Device capabilities */
+ congested_fn *congested_fn; /* Function pointer if device is md/dm */
+ void *congested_data; /* Pointer to aux data for congested func */
+
+ char *name;
+
+ unsigned int min_ratio;
+ unsigned int max_ratio, max_prop_frac;
+
+ struct bdi_writeback wb; /* default writeback info for this bdi */
+
+ struct device *dev;
+
+ struct timer_list laptop_mode_wb_timer;
+
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *debug_dir;
+ struct dentry *debug_stats;
+#endif
+};
+
+enum {
+ BLK_RW_ASYNC = 0,
+ BLK_RW_SYNC = 1,
+};
+
+void clear_bdi_congested(struct backing_dev_info *bdi, int sync);
+void set_bdi_congested(struct backing_dev_info *bdi, int sync);
+
+#endif /* __LINUX_BACKING_DEV_DEFS_H */