linux/include/linux/backing-dev.h at master · fabgithub/linux · GitHub

Repository navigation

History

359 lines (295 loc) · 10.1 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

* include/linux/backing-dev.h

* low-level device information and state which is propagated up through

* to high-level code.

#ifndef _LINUX_BACKING_DEV_H

#define _LINUX_BACKING_DEV_H

#include <linux/percpu_counter.h>

#include <linux/log2.h>

#include <linux/flex_proportions.h>

#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/sched.h>

#include <linux/timer.h>

#include <linux/writeback.h>

#include <linux/atomic.h>

#include <linux/sysctl.h>

#include <linux/workqueue.h>

struct page;

struct device;

struct dentry;

* Bits in backing_dev_info.state

enum bdi_state {

BDI_wb_alloc, /* Default embedded wb allocated */

BDI_async_congested, /* The async (write) queue is getting full */

BDI_sync_congested, /* The sync queue is getting full */

BDI_registered, /* bdi_register() was done */

BDI_writeback_running, /* Writeback is in progress */

BDI_unused, /* Available bits start here */

};

typedef int (congested_fn)(void *, int);

enum bdi_stat_item {

BDI_RECLAIMABLE,

BDI_WRITEBACK,

BDI_DIRTIED,

BDI_WRITTEN,

NR_BDI_STAT_ITEMS

};

#define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))

struct bdi_writeback {

struct backing_dev_info *bdi; /* our parent bdi */

unsigned int nr;

unsigned long last_old_flush; /* last old data flush */

struct delayed_work dwork; /* work item used for writeback */

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 */

spinlock_t list_lock; /* protects the b_* lists */

};

struct backing_dev_info {

struct list_head bdi_list;

unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */

unsigned long state; /* Always use atomic bitops on this */

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;

struct percpu_counter bdi_stat[NR_BDI_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;

unsigned int min_ratio;

unsigned int max_ratio, max_prop_frac;

struct bdi_writeback wb; /* default writeback info for this bdi */

spinlock_t wb_lock; /* protects work_list */

struct list_head work_list;

struct device *dev;

struct timer_list laptop_mode_wb_timer;

#ifdef CONFIG_DEBUG_FS

struct dentry *debug_dir;

struct dentry *debug_stats;

#endif

};

int bdi_init(struct backing_dev_info *bdi);

void bdi_destroy(struct backing_dev_info *bdi);

__printf(3, 4)

int bdi_register(struct backing_dev_info *bdi, struct device *parent,

const char *fmt, ...);

int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);

void bdi_unregister(struct backing_dev_info *bdi);

int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int);

void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,

enum wb_reason reason);

void bdi_start_background_writeback(struct backing_dev_info *bdi);

void bdi_writeback_workfn(struct work_struct *work);

int bdi_has_dirty_io(struct backing_dev_info *bdi);

void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi);

void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2);

extern spinlock_t bdi_lock;

extern struct list_head bdi_list;

extern struct workqueue_struct *bdi_wq;

static inline int wb_has_dirty_io(struct bdi_writeback *wb)

{

return !list_empty(&wb->b_dirty) ||

!list_empty(&wb->b_io) ||

!list_empty(&wb->b_more_io);

}

static inline void __add_bdi_stat(struct backing_dev_info *bdi,

enum bdi_stat_item item, s64 amount)

{

__percpu_counter_add(&bdi->bdi_stat[item], amount, BDI_STAT_BATCH);

}

static inline void __inc_bdi_stat(struct backing_dev_info *bdi,

enum bdi_stat_item item)

{

__add_bdi_stat(bdi, item, 1);

}

static inline void inc_bdi_stat(struct backing_dev_info *bdi,

enum bdi_stat_item item)

{

unsigned long flags;

local_irq_save(flags);

__inc_bdi_stat(bdi, item);

local_irq_restore(flags);

}

static inline void __dec_bdi_stat(struct backing_dev_info *bdi,

enum bdi_stat_item item)

{

__add_bdi_stat(bdi, item, -1);

}

static inline void dec_bdi_stat(struct backing_dev_info *bdi,

enum bdi_stat_item item)

{

unsigned long flags;

local_irq_save(flags);

__dec_bdi_stat(bdi, item);

local_irq_restore(flags);

}

static inline s64 bdi_stat(struct backing_dev_info *bdi,

enum bdi_stat_item item)

{

return percpu_counter_read_positive(&bdi->bdi_stat[item]);

}

static inline s64 __bdi_stat_sum(struct backing_dev_info *bdi,

enum bdi_stat_item item)

{

return percpu_counter_sum_positive(&bdi->bdi_stat[item]);

}

static inline s64 bdi_stat_sum(struct backing_dev_info *bdi,

enum bdi_stat_item item)

{

s64 sum;

unsigned long flags;

local_irq_save(flags);

sum = __bdi_stat_sum(bdi, item);

local_irq_restore(flags);

return sum;

}

extern void bdi_writeout_inc(struct backing_dev_info *bdi);

* maximal error of a stat counter.

static inline unsigned long bdi_stat_error(struct backing_dev_info *bdi)

{

#ifdef CONFIG_SMP

return nr_cpu_ids * BDI_STAT_BATCH;

#else

return 1;

#endif

}

int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);

int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);

* Flags in backing_dev_info::capability

* The first three flags control whether dirty pages will contribute to the

* VM's accounting and whether writepages() should be called for dirty pages

* (something that would not, for example, be appropriate for ramfs)

* WARNING: these flags are closely related and should not normally be

* used separately. The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these

* three flags into a single convenience macro.

* BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting

* BDI_CAP_NO_WRITEBACK: Don't write pages back

* BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages

* These flags let !MMU mmap() govern direct device mapping vs immediate

* copying more easily for MAP_PRIVATE, especially for ROM filesystems.

* BDI_CAP_MAP_COPY: Copy can be mapped (MAP_PRIVATE)

* BDI_CAP_MAP_DIRECT: Can be mapped directly (MAP_SHARED)

* BDI_CAP_READ_MAP: Can be mapped for reading

* BDI_CAP_WRITE_MAP: Can be mapped for writing

* BDI_CAP_EXEC_MAP: Can be mapped for execution

* BDI_CAP_SWAP_BACKED: Count shmem/tmpfs objects as swap-backed.

#define BDI_CAP_NO_ACCT_DIRTY 0x00000001

#define BDI_CAP_NO_WRITEBACK 0x00000002

#define BDI_CAP_MAP_COPY 0x00000004

#define BDI_CAP_MAP_DIRECT 0x00000008

#define BDI_CAP_READ_MAP 0x00000010

#define BDI_CAP_WRITE_MAP 0x00000020

#define BDI_CAP_EXEC_MAP 0x00000040

#define BDI_CAP_NO_ACCT_WB 0x00000080

#define BDI_CAP_SWAP_BACKED 0x00000100

#define BDI_CAP_STABLE_WRITES 0x00000200

#define BDI_CAP_VMFLAGS \

(BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP)

#define BDI_CAP_NO_ACCT_AND_WRITEBACK \

(BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)

#if defined(VM_MAYREAD) && \

(BDI_CAP_READ_MAP != VM_MAYREAD || \

BDI_CAP_WRITE_MAP != VM_MAYWRITE || \

BDI_CAP_EXEC_MAP != VM_MAYEXEC)

#error please change backing_dev_info::capabilities flags

#endif

extern struct backing_dev_info default_backing_dev_info;

extern struct backing_dev_info noop_backing_dev_info;

int writeback_in_progress(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 bdi_congested(bdi, 1 << BDI_sync_congested);

}

static inline int bdi_write_congested(struct backing_dev_info *bdi)

{

return bdi_congested(bdi, 1 << BDI_async_congested);

}

static inline int bdi_rw_congested(struct backing_dev_info *bdi)

{

return bdi_congested(bdi, (1 << BDI_sync_congested) |

(1 << BDI_async_congested));

}

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);

long congestion_wait(int sync, long timeout);

long wait_iff_congested(struct zone *zone, int sync, long timeout);

int pdflush_proc_obsolete(struct ctl_table *table, int write,

void __user *buffer, size_t *lenp, loff_t *ppos);

static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi)

{

return bdi->capabilities & BDI_CAP_STABLE_WRITES;

}

static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)

{

return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);

}

static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)

{

return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);

}

static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)

{

/* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */

return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |

BDI_CAP_NO_WRITEBACK));

}

static inline bool bdi_cap_swap_backed(struct backing_dev_info *bdi)

{

return bdi->capabilities & BDI_CAP_SWAP_BACKED;

}

static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)

{

return bdi_cap_writeback_dirty(mapping->backing_dev_info);

}

static inline bool mapping_cap_account_dirty(struct address_space *mapping)

{

return bdi_cap_account_dirty(mapping->backing_dev_info);

}

static inline bool mapping_cap_swap_backed(struct address_space *mapping)

{

return bdi_cap_swap_backed(mapping->backing_dev_info);

}

static inline int bdi_sched_wait(void *word)

{

schedule();

return 0;

}

#endif /* _LINUX_BACKING_DEV_H */

linux/include/linux/backing-dev.h at master · fabgithub/linux · GitHub

Repository navigation

Expand file tree

Breadcrumbs

backing-dev.h

Latest commit

History

Breadcrumbs

backing-dev.h

File metadata and controls