~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/backing-dev-defs.h

Version: ~ [ linux-5.3 ] ~ [ linux-5.2.15 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.73 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.144 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.193 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.193 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.73 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 #ifndef __LINUX_BACKING_DEV_DEFS_H
  2 #define __LINUX_BACKING_DEV_DEFS_H
  3 
  4 #include <linux/list.h>
  5 #include <linux/radix-tree.h>
  6 #include <linux/rbtree.h>
  7 #include <linux/spinlock.h>
  8 #include <linux/percpu_counter.h>
  9 #include <linux/percpu-refcount.h>
 10 #include <linux/flex_proportions.h>
 11 #include <linux/timer.h>
 12 #include <linux/workqueue.h>
 13 
 14 struct page;
 15 struct device;
 16 struct dentry;
 17 
 18 /*
 19  * Bits in bdi_writeback.state
 20  */
 21 enum wb_state {
 22         WB_registered,          /* bdi_register() was done */
 23         WB_writeback_running,   /* Writeback is in progress */
 24         WB_has_dirty_io,        /* Dirty inodes on ->b_{dirty|io|more_io} */
 25 };
 26 
 27 enum wb_congested_state {
 28         WB_async_congested,     /* The async (write) queue is getting full */
 29         WB_sync_congested,      /* The sync queue is getting full */
 30 };
 31 
 32 typedef int (congested_fn)(void *, int);
 33 
 34 enum wb_stat_item {
 35         WB_RECLAIMABLE,
 36         WB_WRITEBACK,
 37         WB_DIRTIED,
 38         WB_WRITTEN,
 39         NR_WB_STAT_ITEMS
 40 };
 41 
 42 #define WB_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
 43 
 44 /*
 45  * For cgroup writeback, multiple wb's may map to the same blkcg.  Those
 46  * wb's can operate mostly independently but should share the congested
 47  * state.  To facilitate such sharing, the congested state is tracked using
 48  * the following struct which is created on demand, indexed by blkcg ID on
 49  * its bdi, and refcounted.
 50  */
 51 struct bdi_writeback_congested {
 52         unsigned long state;            /* WB_[a]sync_congested flags */
 53         atomic_t refcnt;                /* nr of attached wb's and blkg */
 54 
 55 #ifdef CONFIG_CGROUP_WRITEBACK
 56         struct backing_dev_info *bdi;   /* the associated bdi */
 57         int blkcg_id;                   /* ID of the associated blkcg */
 58         struct rb_node rb_node;         /* on bdi->cgwb_congestion_tree */
 59 #endif
 60 };
 61 
 62 /*
 63  * Each wb (bdi_writeback) can perform writeback operations, is measured
 64  * and throttled, independently.  Without cgroup writeback, each bdi
 65  * (bdi_writeback) is served by its embedded bdi->wb.
 66  *
 67  * On the default hierarchy, blkcg implicitly enables memcg.  This allows
 68  * using memcg's page ownership for attributing writeback IOs, and every
 69  * memcg - blkcg combination can be served by its own wb by assigning a
 70  * dedicated wb to each memcg, which enables isolation across different
 71  * cgroups and propagation of IO back pressure down from the IO layer upto
 72  * the tasks which are generating the dirty pages to be written back.
 73  *
 74  * A cgroup wb is indexed on its bdi by the ID of the associated memcg,
 75  * refcounted with the number of inodes attached to it, and pins the memcg
 76  * and the corresponding blkcg.  As the corresponding blkcg for a memcg may
 77  * change as blkcg is disabled and enabled higher up in the hierarchy, a wb
 78  * is tested for blkcg after lookup and removed from index on mismatch so
 79  * that a new wb for the combination can be created.
 80  */
 81 struct bdi_writeback {
 82         struct backing_dev_info *bdi;   /* our parent bdi */
 83 
 84         unsigned long state;            /* Always use atomic bitops on this */
 85         unsigned long last_old_flush;   /* last old data flush */
 86 
 87         struct list_head b_dirty;       /* dirty inodes */
 88         struct list_head b_io;          /* parked for writeback */
 89         struct list_head b_more_io;     /* parked for more writeback */
 90         struct list_head b_dirty_time;  /* time stamps are dirty */
 91         spinlock_t list_lock;           /* protects the b_* lists */
 92 
 93         struct percpu_counter stat[NR_WB_STAT_ITEMS];
 94 
 95         struct bdi_writeback_congested *congested;
 96 
 97         unsigned long bw_time_stamp;    /* last time write bw is updated */
 98         unsigned long dirtied_stamp;
 99         unsigned long written_stamp;    /* pages written at bw_time_stamp */
100         unsigned long write_bandwidth;  /* the estimated write bandwidth */
101         unsigned long avg_write_bandwidth; /* further smoothed write bw, > 0 */
102 
103         /*
104          * The base dirty throttle rate, re-calculated on every 200ms.
105          * All the bdi tasks' dirty rate will be curbed under it.
106          * @dirty_ratelimit tracks the estimated @balanced_dirty_ratelimit
107          * in small steps and is much more smooth/stable than the latter.
108          */
109         unsigned long dirty_ratelimit;
110         unsigned long balanced_dirty_ratelimit;
111 
112         struct fprop_local_percpu completions;
113         int dirty_exceeded;
114 
115         spinlock_t work_lock;           /* protects work_list & dwork scheduling */
116         struct list_head work_list;
117         struct delayed_work dwork;      /* work item used for writeback */
118 
119         unsigned long dirty_sleep;      /* last wait */
120 
121         struct list_head bdi_node;      /* anchored at bdi->wb_list */
122 
123 #ifdef CONFIG_CGROUP_WRITEBACK
124         struct percpu_ref refcnt;       /* used only for !root wb's */
125         struct fprop_local_percpu memcg_completions;
126         struct cgroup_subsys_state *memcg_css; /* the associated memcg */
127         struct cgroup_subsys_state *blkcg_css; /* and blkcg */
128         struct list_head memcg_node;    /* anchored at memcg->cgwb_list */
129         struct list_head blkcg_node;    /* anchored at blkcg->cgwb_list */
130 
131         union {
132                 struct work_struct release_work;
133                 struct rcu_head rcu;
134         };
135 #endif
136 };
137 
138 struct backing_dev_info {
139         struct list_head bdi_list;
140         unsigned long ra_pages; /* max readahead in PAGE_SIZE units */
141         unsigned long io_pages; /* max allowed IO size */
142         congested_fn *congested_fn; /* Function pointer if device is md/dm */
143         void *congested_data;   /* Pointer to aux data for congested func */
144 
145         char *name;
146 
147         unsigned int capabilities; /* Device capabilities */
148         unsigned int min_ratio;
149         unsigned int max_ratio, max_prop_frac;
150 
151         /*
152          * Sum of avg_write_bw of wbs with dirty inodes.  > 0 if there are
153          * any dirty wbs, which is depended upon by bdi_has_dirty().
154          */
155         atomic_long_t tot_write_bandwidth;
156 
157         struct bdi_writeback wb;  /* the root writeback info for this bdi */
158         struct list_head wb_list; /* list of all wbs */
159 #ifdef CONFIG_CGROUP_WRITEBACK
160         struct radix_tree_root cgwb_tree; /* radix tree of active cgroup wbs */
161         struct rb_root cgwb_congested_tree; /* their congested states */
162         atomic_t usage_cnt; /* counts both cgwbs and cgwb_contested's */
163 #else
164         struct bdi_writeback_congested *wb_congested;
165 #endif
166         wait_queue_head_t wb_waitq;
167 
168         struct device *dev;
169         struct device *owner;
170 
171         struct timer_list laptop_mode_wb_timer;
172 
173 #ifdef CONFIG_DEBUG_FS
174         struct dentry *debug_dir;
175         struct dentry *debug_stats;
176 #endif
177 };
178 
179 enum {
180         BLK_RW_ASYNC    = 0,
181         BLK_RW_SYNC     = 1,
182 };
183 
184 void clear_wb_congested(struct bdi_writeback_congested *congested, int sync);
185 void set_wb_congested(struct bdi_writeback_congested *congested, int sync);
186 
187 static inline void clear_bdi_congested(struct backing_dev_info *bdi, int sync)
188 {
189         clear_wb_congested(bdi->wb.congested, sync);
190 }
191 
192 static inline void set_bdi_congested(struct backing_dev_info *bdi, int sync)
193 {
194         set_wb_congested(bdi->wb.congested, sync);
195 }
196 
197 #ifdef CONFIG_CGROUP_WRITEBACK
198 
199 /**
200  * wb_tryget - try to increment a wb's refcount
201  * @wb: bdi_writeback to get
202  */
203 static inline bool wb_tryget(struct bdi_writeback *wb)
204 {
205         if (wb != &wb->bdi->wb)
206                 return percpu_ref_tryget(&wb->refcnt);
207         return true;
208 }
209 
210 /**
211  * wb_get - increment a wb's refcount
212  * @wb: bdi_writeback to get
213  */
214 static inline void wb_get(struct bdi_writeback *wb)
215 {
216         if (wb != &wb->bdi->wb)
217                 percpu_ref_get(&wb->refcnt);
218 }
219 
220 /**
221  * wb_put - decrement a wb's refcount
222  * @wb: bdi_writeback to put
223  */
224 static inline void wb_put(struct bdi_writeback *wb)
225 {
226         if (wb != &wb->bdi->wb)
227                 percpu_ref_put(&wb->refcnt);
228 }
229 
230 /**
231  * wb_dying - is a wb dying?
232  * @wb: bdi_writeback of interest
233  *
234  * Returns whether @wb is unlinked and being drained.
235  */
236 static inline bool wb_dying(struct bdi_writeback *wb)
237 {
238         return percpu_ref_is_dying(&wb->refcnt);
239 }
240 
241 #else   /* CONFIG_CGROUP_WRITEBACK */
242 
243 static inline bool wb_tryget(struct bdi_writeback *wb)
244 {
245         return true;
246 }
247 
248 static inline void wb_get(struct bdi_writeback *wb)
249 {
250 }
251 
252 static inline void wb_put(struct bdi_writeback *wb)
253 {
254 }
255 
256 static inline bool wb_dying(struct bdi_writeback *wb)
257 {
258         return false;
259 }
260 
261 #endif  /* CONFIG_CGROUP_WRITEBACK */
262 
263 #endif  /* __LINUX_BACKING_DEV_DEFS_H */
264 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp