xref: /openbmc/linux/fs/ceph/super.h (revision 8a26af30)
1 #ifndef _FS_CEPH_SUPER_H
2 #define _FS_CEPH_SUPER_H
3 
4 #include <linux/ceph/ceph_debug.h>
5 
6 #include <asm/unaligned.h>
7 #include <linux/backing-dev.h>
8 #include <linux/completion.h>
9 #include <linux/exportfs.h>
10 #include <linux/fs.h>
11 #include <linux/mempool.h>
12 #include <linux/pagemap.h>
13 #include <linux/wait.h>
14 #include <linux/writeback.h>
15 #include <linux/slab.h>
16 #include <linux/posix_acl.h>
17 
18 #include <linux/ceph/libceph.h>
19 
20 #ifdef CONFIG_CEPH_FSCACHE
21 #include <linux/fscache.h>
22 #endif
23 
24 /* f_type in struct statfs */
25 #define CEPH_SUPER_MAGIC 0x00c36400
26 
27 /* large granularity for statfs utilization stats to facilitate
28  * large volume sizes on 32-bit machines. */
29 #define CEPH_BLOCK_SHIFT   22  /* 4 MB */
30 #define CEPH_BLOCK         (1 << CEPH_BLOCK_SHIFT)
31 
32 #define CEPH_MOUNT_OPT_DIRSTAT         (1<<4) /* `cat dirname` for stats */
33 #define CEPH_MOUNT_OPT_RBYTES          (1<<5) /* dir st_bytes = rbytes */
34 #define CEPH_MOUNT_OPT_NOASYNCREADDIR  (1<<7) /* no dcache readdir */
35 #define CEPH_MOUNT_OPT_INO32           (1<<8) /* 32 bit inos */
36 #define CEPH_MOUNT_OPT_DCACHE          (1<<9) /* use dcache for readdir etc */
37 #define CEPH_MOUNT_OPT_FSCACHE         (1<<10) /* use fscache */
38 
39 #define CEPH_MOUNT_OPT_DEFAULT    (CEPH_MOUNT_OPT_RBYTES)
40 
41 #define ceph_set_mount_opt(fsc, opt) \
42 	(fsc)->mount_options->flags |= CEPH_MOUNT_OPT_##opt;
43 #define ceph_test_mount_opt(fsc, opt) \
44 	(!!((fsc)->mount_options->flags & CEPH_MOUNT_OPT_##opt))
45 
46 #define CEPH_RSIZE_DEFAULT             0           /* max read size */
47 #define CEPH_RASIZE_DEFAULT            (8192*1024) /* readahead */
48 #define CEPH_MAX_READDIR_DEFAULT        1024
49 #define CEPH_MAX_READDIR_BYTES_DEFAULT  (512*1024)
50 #define CEPH_SNAPDIRNAME_DEFAULT        ".snap"
51 
52 struct ceph_mount_options {
53 	int flags;
54 	int sb_flags;
55 
56 	int wsize;            /* max write size */
57 	int rsize;            /* max read size */
58 	int rasize;           /* max readahead */
59 	int congestion_kb;    /* max writeback in flight */
60 	int caps_wanted_delay_min, caps_wanted_delay_max;
61 	int cap_release_safety;
62 	int max_readdir;       /* max readdir result (entires) */
63 	int max_readdir_bytes; /* max readdir result (bytes) */
64 
65 	/*
66 	 * everything above this point can be memcmp'd; everything below
67 	 * is handled in compare_mount_options()
68 	 */
69 
70 	char *snapdir_name;   /* default ".snap" */
71 };
72 
73 struct ceph_fs_client {
74 	struct super_block *sb;
75 
76 	struct ceph_mount_options *mount_options;
77 	struct ceph_client *client;
78 
79 	unsigned long mount_state;
80 	int min_caps;                  /* min caps i added */
81 
82 	struct ceph_mds_client *mdsc;
83 
84 	/* writeback */
85 	mempool_t *wb_pagevec_pool;
86 	struct workqueue_struct *wb_wq;
87 	struct workqueue_struct *pg_inv_wq;
88 	struct workqueue_struct *trunc_wq;
89 	atomic_long_t writeback_count;
90 
91 	struct backing_dev_info backing_dev_info;
92 
93 #ifdef CONFIG_DEBUG_FS
94 	struct dentry *debugfs_dentry_lru, *debugfs_caps;
95 	struct dentry *debugfs_congestion_kb;
96 	struct dentry *debugfs_bdi;
97 	struct dentry *debugfs_mdsc, *debugfs_mdsmap;
98 #endif
99 
100 #ifdef CONFIG_CEPH_FSCACHE
101 	struct fscache_cookie *fscache;
102 	struct workqueue_struct *revalidate_wq;
103 #endif
104 };
105 
106 
107 /*
108  * File i/o capability.  This tracks shared state with the metadata
109  * server that allows us to cache or writeback attributes or to read
110  * and write data.  For any given inode, we should have one or more
111  * capabilities, one issued by each metadata server, and our
112  * cumulative access is the OR of all issued capabilities.
113  *
114  * Each cap is referenced by the inode's i_caps rbtree and by per-mds
115  * session capability lists.
116  */
117 struct ceph_cap {
118 	struct ceph_inode_info *ci;
119 	struct rb_node ci_node;          /* per-ci cap tree */
120 	struct ceph_mds_session *session;
121 	struct list_head session_caps;   /* per-session caplist */
122 	int mds;
123 	u64 cap_id;       /* unique cap id (mds provided) */
124 	int issued;       /* latest, from the mds */
125 	int implemented;  /* implemented superset of issued (for revocation) */
126 	int mds_wanted;
127 	u32 seq, issue_seq, mseq;
128 	u32 cap_gen;      /* active/stale cycle */
129 	unsigned long last_used;
130 	struct list_head caps_item;
131 };
132 
133 #define CHECK_CAPS_NODELAY    1  /* do not delay any further */
134 #define CHECK_CAPS_AUTHONLY   2  /* only check auth cap */
135 #define CHECK_CAPS_FLUSH      4  /* flush any dirty caps */
136 
137 /*
138  * Snapped cap state that is pending flush to mds.  When a snapshot occurs,
139  * we first complete any in-process sync writes and writeback any dirty
140  * data before flushing the snapped state (tracked here) back to the MDS.
141  */
142 struct ceph_cap_snap {
143 	atomic_t nref;
144 	struct ceph_inode_info *ci;
145 	struct list_head ci_item, flushing_item;
146 
147 	u64 follows, flush_tid;
148 	int issued, dirty;
149 	struct ceph_snap_context *context;
150 
151 	umode_t mode;
152 	kuid_t uid;
153 	kgid_t gid;
154 
155 	struct ceph_buffer *xattr_blob;
156 	u64 xattr_version;
157 
158 	u64 size;
159 	struct timespec mtime, atime, ctime;
160 	u64 time_warp_seq;
161 	int writing;   /* a sync write is still in progress */
162 	int dirty_pages;     /* dirty pages awaiting writeback */
163 };
164 
165 static inline void ceph_put_cap_snap(struct ceph_cap_snap *capsnap)
166 {
167 	if (atomic_dec_and_test(&capsnap->nref)) {
168 		if (capsnap->xattr_blob)
169 			ceph_buffer_put(capsnap->xattr_blob);
170 		kfree(capsnap);
171 	}
172 }
173 
174 /*
175  * The frag tree describes how a directory is fragmented, potentially across
176  * multiple metadata servers.  It is also used to indicate points where
177  * metadata authority is delegated, and whether/where metadata is replicated.
178  *
179  * A _leaf_ frag will be present in the i_fragtree IFF there is
180  * delegation info.  That is, if mds >= 0 || ndist > 0.
181  */
182 #define CEPH_MAX_DIRFRAG_REP 4
183 
184 struct ceph_inode_frag {
185 	struct rb_node node;
186 
187 	/* fragtree state */
188 	u32 frag;
189 	int split_by;         /* i.e. 2^(split_by) children */
190 
191 	/* delegation and replication info */
192 	int mds;              /* -1 if same authority as parent */
193 	int ndist;            /* >0 if replicated */
194 	int dist[CEPH_MAX_DIRFRAG_REP];
195 };
196 
197 /*
198  * We cache inode xattrs as an encoded blob until they are first used,
199  * at which point we parse them into an rbtree.
200  */
201 struct ceph_inode_xattr {
202 	struct rb_node node;
203 
204 	const char *name;
205 	int name_len;
206 	const char *val;
207 	int val_len;
208 	int dirty;
209 
210 	int should_free_name;
211 	int should_free_val;
212 };
213 
214 /*
215  * Ceph dentry state
216  */
217 struct ceph_dentry_info {
218 	struct ceph_mds_session *lease_session;
219 	u32 lease_gen, lease_shared_gen;
220 	u32 lease_seq;
221 	unsigned long lease_renew_after, lease_renew_from;
222 	struct list_head lru;
223 	struct dentry *dentry;
224 	u64 time;
225 	u64 offset;
226 };
227 
228 struct ceph_inode_xattrs_info {
229 	/*
230 	 * (still encoded) xattr blob. we avoid the overhead of parsing
231 	 * this until someone actually calls getxattr, etc.
232 	 *
233 	 * blob->vec.iov_len == 4 implies there are no xattrs; blob ==
234 	 * NULL means we don't know.
235 	*/
236 	struct ceph_buffer *blob, *prealloc_blob;
237 
238 	struct rb_root index;
239 	bool dirty;
240 	int count;
241 	int names_size;
242 	int vals_size;
243 	u64 version, index_version;
244 };
245 
246 /*
247  * Ceph inode.
248  */
249 struct ceph_inode_info {
250 	struct ceph_vino i_vino;   /* ceph ino + snap */
251 
252 	spinlock_t i_ceph_lock;
253 
254 	u64 i_version;
255 	u32 i_time_warp_seq;
256 
257 	unsigned i_ceph_flags;
258 	atomic_t i_release_count;
259 	atomic_t i_complete_count;
260 
261 	struct ceph_dir_layout i_dir_layout;
262 	struct ceph_file_layout i_layout;
263 	char *i_symlink;
264 
265 	/* for dirs */
266 	struct timespec i_rctime;
267 	u64 i_rbytes, i_rfiles, i_rsubdirs;
268 	u64 i_files, i_subdirs;
269 
270 	struct rb_root i_fragtree;
271 	struct mutex i_fragtree_mutex;
272 
273 	struct ceph_inode_xattrs_info i_xattrs;
274 
275 	/* capabilities.  protected _both_ by i_ceph_lock and cap->session's
276 	 * s_mutex. */
277 	struct rb_root i_caps;           /* cap list */
278 	struct ceph_cap *i_auth_cap;     /* authoritative cap, if any */
279 	unsigned i_dirty_caps, i_flushing_caps;     /* mask of dirtied fields */
280 	struct list_head i_dirty_item, i_flushing_item;
281 	u64 i_cap_flush_seq;
282 	/* we need to track cap writeback on a per-cap-bit basis, to allow
283 	 * overlapping, pipelined cap flushes to the mds.  we can probably
284 	 * reduce the tid to 8 bits if we're concerned about inode size. */
285 	u16 i_cap_flush_last_tid, i_cap_flush_tid[CEPH_CAP_BITS];
286 	wait_queue_head_t i_cap_wq;      /* threads waiting on a capability */
287 	unsigned long i_hold_caps_min; /* jiffies */
288 	unsigned long i_hold_caps_max; /* jiffies */
289 	struct list_head i_cap_delay_list;  /* for delayed cap release to mds */
290 	struct ceph_cap_reservation i_cap_migration_resv;
291 	struct list_head i_cap_snaps;   /* snapped state pending flush to mds */
292 	struct ceph_snap_context *i_head_snapc;  /* set if wr_buffer_head > 0 or
293 						    dirty|flushing caps */
294 	unsigned i_snap_caps;           /* cap bits for snapped files */
295 
296 	int i_nr_by_mode[CEPH_FILE_MODE_NUM];  /* open file counts */
297 
298 	struct mutex i_truncate_mutex;
299 	u32 i_truncate_seq;        /* last truncate to smaller size */
300 	u64 i_truncate_size;       /*  and the size we last truncated down to */
301 	int i_truncate_pending;    /*  still need to call vmtruncate */
302 
303 	u64 i_max_size;            /* max file size authorized by mds */
304 	u64 i_reported_size; /* (max_)size reported to or requested of mds */
305 	u64 i_wanted_max_size;     /* offset we'd like to write too */
306 	u64 i_requested_max_size;  /* max_size we've requested */
307 
308 	/* held references to caps */
309 	int i_pin_ref;
310 	int i_rd_ref, i_rdcache_ref, i_wr_ref, i_wb_ref;
311 	int i_wrbuffer_ref, i_wrbuffer_ref_head;
312 	u32 i_shared_gen;       /* increment each time we get FILE_SHARED */
313 	u32 i_rdcache_gen;      /* incremented each time we get FILE_CACHE. */
314 	u32 i_rdcache_revoking; /* RDCACHE gen to async invalidate, if any */
315 
316 	struct list_head i_unsafe_writes; /* uncommitted sync writes */
317 	struct list_head i_unsafe_dirops; /* uncommitted mds dir ops */
318 	spinlock_t i_unsafe_lock;
319 
320 	struct ceph_snap_realm *i_snap_realm; /* snap realm (if caps) */
321 	int i_snap_realm_counter; /* snap realm (if caps) */
322 	struct list_head i_snap_realm_item;
323 	struct list_head i_snap_flush_item;
324 
325 	struct work_struct i_wb_work;  /* writeback work */
326 	struct work_struct i_pg_inv_work;  /* page invalidation work */
327 
328 	struct work_struct i_vmtruncate_work;
329 
330 #ifdef CONFIG_CEPH_FSCACHE
331 	struct fscache_cookie *fscache;
332 	u32 i_fscache_gen; /* sequence, for delayed fscache validate */
333 	struct work_struct i_revalidate_work;
334 #endif
335 	struct inode vfs_inode; /* at end */
336 };
337 
338 static inline struct ceph_inode_info *ceph_inode(struct inode *inode)
339 {
340 	return container_of(inode, struct ceph_inode_info, vfs_inode);
341 }
342 
343 static inline struct ceph_fs_client *ceph_inode_to_client(struct inode *inode)
344 {
345 	return (struct ceph_fs_client *)inode->i_sb->s_fs_info;
346 }
347 
348 static inline struct ceph_fs_client *ceph_sb_to_client(struct super_block *sb)
349 {
350 	return (struct ceph_fs_client *)sb->s_fs_info;
351 }
352 
353 static inline struct ceph_vino ceph_vino(struct inode *inode)
354 {
355 	return ceph_inode(inode)->i_vino;
356 }
357 
358 /*
359  * ino_t is <64 bits on many architectures, blech.
360  *
361  *               i_ino (kernel inode)   st_ino (userspace)
362  * i386          32                     32
363  * x86_64+ino32  64                     32
364  * x86_64        64                     64
365  */
366 static inline u32 ceph_ino_to_ino32(__u64 vino)
367 {
368 	u32 ino = vino & 0xffffffff;
369 	ino ^= vino >> 32;
370 	if (!ino)
371 		ino = 2;
372 	return ino;
373 }
374 
375 /*
376  * kernel i_ino value
377  */
378 static inline ino_t ceph_vino_to_ino(struct ceph_vino vino)
379 {
380 #if BITS_PER_LONG == 32
381 	return ceph_ino_to_ino32(vino.ino);
382 #else
383 	return (ino_t)vino.ino;
384 #endif
385 }
386 
387 /*
388  * user-visible ino (stat, filldir)
389  */
390 #if BITS_PER_LONG == 32
391 static inline ino_t ceph_translate_ino(struct super_block *sb, ino_t ino)
392 {
393 	return ino;
394 }
395 #else
396 static inline ino_t ceph_translate_ino(struct super_block *sb, ino_t ino)
397 {
398 	if (ceph_test_mount_opt(ceph_sb_to_client(sb), INO32))
399 		ino = ceph_ino_to_ino32(ino);
400 	return ino;
401 }
402 #endif
403 
404 
405 /* for printf-style formatting */
406 #define ceph_vinop(i) ceph_inode(i)->i_vino.ino, ceph_inode(i)->i_vino.snap
407 
408 static inline u64 ceph_ino(struct inode *inode)
409 {
410 	return ceph_inode(inode)->i_vino.ino;
411 }
412 static inline u64 ceph_snap(struct inode *inode)
413 {
414 	return ceph_inode(inode)->i_vino.snap;
415 }
416 
417 static inline int ceph_ino_compare(struct inode *inode, void *data)
418 {
419 	struct ceph_vino *pvino = (struct ceph_vino *)data;
420 	struct ceph_inode_info *ci = ceph_inode(inode);
421 	return ci->i_vino.ino == pvino->ino &&
422 		ci->i_vino.snap == pvino->snap;
423 }
424 
425 static inline struct inode *ceph_find_inode(struct super_block *sb,
426 					    struct ceph_vino vino)
427 {
428 	ino_t t = ceph_vino_to_ino(vino);
429 	return ilookup5(sb, t, ceph_ino_compare, &vino);
430 }
431 
432 
433 /*
434  * Ceph inode.
435  */
436 #define CEPH_I_NODELAY   4  /* do not delay cap release */
437 #define CEPH_I_FLUSH     8  /* do not delay flush of dirty metadata */
438 #define CEPH_I_NOFLUSH  16  /* do not flush dirty caps */
439 
440 static inline void __ceph_dir_set_complete(struct ceph_inode_info *ci,
441 					   int release_count)
442 {
443 	atomic_set(&ci->i_complete_count, release_count);
444 }
445 
446 static inline void __ceph_dir_clear_complete(struct ceph_inode_info *ci)
447 {
448 	atomic_inc(&ci->i_release_count);
449 }
450 
451 static inline bool __ceph_dir_is_complete(struct ceph_inode_info *ci)
452 {
453 	return atomic_read(&ci->i_complete_count) ==
454 		atomic_read(&ci->i_release_count);
455 }
456 
457 static inline void ceph_dir_clear_complete(struct inode *inode)
458 {
459 	__ceph_dir_clear_complete(ceph_inode(inode));
460 }
461 
462 static inline bool ceph_dir_is_complete(struct inode *inode)
463 {
464 	return __ceph_dir_is_complete(ceph_inode(inode));
465 }
466 
467 
468 /* find a specific frag @f */
469 extern struct ceph_inode_frag *__ceph_find_frag(struct ceph_inode_info *ci,
470 						u32 f);
471 
472 /*
473  * choose fragment for value @v.  copy frag content to pfrag, if leaf
474  * exists
475  */
476 extern u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
477 			    struct ceph_inode_frag *pfrag,
478 			    int *found);
479 
480 static inline struct ceph_dentry_info *ceph_dentry(struct dentry *dentry)
481 {
482 	return (struct ceph_dentry_info *)dentry->d_fsdata;
483 }
484 
485 static inline loff_t ceph_make_fpos(unsigned frag, unsigned off)
486 {
487 	return ((loff_t)frag << 32) | (loff_t)off;
488 }
489 
490 /*
491  * caps helpers
492  */
493 static inline bool __ceph_is_any_real_caps(struct ceph_inode_info *ci)
494 {
495 	return !RB_EMPTY_ROOT(&ci->i_caps);
496 }
497 
498 extern int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented);
499 extern int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int t);
500 extern int __ceph_caps_issued_other(struct ceph_inode_info *ci,
501 				    struct ceph_cap *cap);
502 
503 static inline int ceph_caps_issued(struct ceph_inode_info *ci)
504 {
505 	int issued;
506 	spin_lock(&ci->i_ceph_lock);
507 	issued = __ceph_caps_issued(ci, NULL);
508 	spin_unlock(&ci->i_ceph_lock);
509 	return issued;
510 }
511 
512 static inline int ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask,
513 					int touch)
514 {
515 	int r;
516 	spin_lock(&ci->i_ceph_lock);
517 	r = __ceph_caps_issued_mask(ci, mask, touch);
518 	spin_unlock(&ci->i_ceph_lock);
519 	return r;
520 }
521 
522 static inline int __ceph_caps_dirty(struct ceph_inode_info *ci)
523 {
524 	return ci->i_dirty_caps | ci->i_flushing_caps;
525 }
526 extern int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask);
527 
528 extern int __ceph_caps_revoking_other(struct ceph_inode_info *ci,
529 				      struct ceph_cap *ocap, int mask);
530 extern int ceph_caps_revoking(struct ceph_inode_info *ci, int mask);
531 extern int __ceph_caps_used(struct ceph_inode_info *ci);
532 
533 extern int __ceph_caps_file_wanted(struct ceph_inode_info *ci);
534 
535 /*
536  * wanted, by virtue of open file modes AND cap refs (buffered/cached data)
537  */
538 static inline int __ceph_caps_wanted(struct ceph_inode_info *ci)
539 {
540 	int w = __ceph_caps_file_wanted(ci) | __ceph_caps_used(ci);
541 	if (w & CEPH_CAP_FILE_BUFFER)
542 		w |= CEPH_CAP_FILE_EXCL;  /* we want EXCL if dirty data */
543 	return w;
544 }
545 
546 /* what the mds thinks we want */
547 extern int __ceph_caps_mds_wanted(struct ceph_inode_info *ci);
548 
549 extern void ceph_caps_init(struct ceph_mds_client *mdsc);
550 extern void ceph_caps_finalize(struct ceph_mds_client *mdsc);
551 extern void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta);
552 extern void ceph_reserve_caps(struct ceph_mds_client *mdsc,
553 			     struct ceph_cap_reservation *ctx, int need);
554 extern int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
555 			       struct ceph_cap_reservation *ctx);
556 extern void ceph_reservation_status(struct ceph_fs_client *client,
557 				    int *total, int *avail, int *used,
558 				    int *reserved, int *min);
559 
560 
561 
562 /*
563  * we keep buffered readdir results attached to file->private_data
564  */
565 #define CEPH_F_SYNC     1
566 #define CEPH_F_ATEND    2
567 
568 struct ceph_file_info {
569 	short fmode;     /* initialized on open */
570 	short flags;     /* CEPH_F_* */
571 
572 	/* readdir: position within the dir */
573 	u32 frag;
574 	struct ceph_mds_request *last_readdir;
575 
576 	/* readdir: position within a frag */
577 	unsigned offset;       /* offset of last chunk, adjusted for . and .. */
578 	unsigned next_offset;  /* offset of next chunk (last_name's + 1) */
579 	char *last_name;       /* last entry in previous chunk */
580 	struct dentry *dentry; /* next dentry (for dcache readdir) */
581 	int dir_release_count;
582 
583 	/* used for -o dirstat read() on directory thing */
584 	char *dir_info;
585 	int dir_info_len;
586 };
587 
588 
589 
590 /*
591  * A "snap realm" describes a subset of the file hierarchy sharing
592  * the same set of snapshots that apply to it.  The realms themselves
593  * are organized into a hierarchy, such that children inherit (some of)
594  * the snapshots of their parents.
595  *
596  * All inodes within the realm that have capabilities are linked into a
597  * per-realm list.
598  */
599 struct ceph_snap_realm {
600 	u64 ino;
601 	atomic_t nref;
602 	struct rb_node node;
603 
604 	u64 created, seq;
605 	u64 parent_ino;
606 	u64 parent_since;   /* snapid when our current parent became so */
607 
608 	u64 *prior_parent_snaps;      /* snaps inherited from any parents we */
609 	u32 num_prior_parent_snaps;   /*  had prior to parent_since */
610 	u64 *snaps;                   /* snaps specific to this realm */
611 	u32 num_snaps;
612 
613 	struct ceph_snap_realm *parent;
614 	struct list_head children;       /* list of child realms */
615 	struct list_head child_item;
616 
617 	struct list_head empty_item;     /* if i have ref==0 */
618 
619 	struct list_head dirty_item;     /* if realm needs new context */
620 
621 	/* the current set of snaps for this realm */
622 	struct ceph_snap_context *cached_context;
623 
624 	struct list_head inodes_with_caps;
625 	spinlock_t inodes_with_caps_lock;
626 };
627 
628 static inline int default_congestion_kb(void)
629 {
630 	int congestion_kb;
631 
632 	/*
633 	 * Copied from NFS
634 	 *
635 	 * congestion size, scale with available memory.
636 	 *
637 	 *  64MB:    8192k
638 	 * 128MB:   11585k
639 	 * 256MB:   16384k
640 	 * 512MB:   23170k
641 	 *   1GB:   32768k
642 	 *   2GB:   46340k
643 	 *   4GB:   65536k
644 	 *   8GB:   92681k
645 	 *  16GB:  131072k
646 	 *
647 	 * This allows larger machines to have larger/more transfers.
648 	 * Limit the default to 256M
649 	 */
650 	congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
651 	if (congestion_kb > 256*1024)
652 		congestion_kb = 256*1024;
653 
654 	return congestion_kb;
655 }
656 
657 
658 
659 /* snap.c */
660 struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc,
661 					       u64 ino);
662 extern void ceph_get_snap_realm(struct ceph_mds_client *mdsc,
663 				struct ceph_snap_realm *realm);
664 extern void ceph_put_snap_realm(struct ceph_mds_client *mdsc,
665 				struct ceph_snap_realm *realm);
666 extern int ceph_update_snap_trace(struct ceph_mds_client *m,
667 				  void *p, void *e, bool deletion);
668 extern void ceph_handle_snap(struct ceph_mds_client *mdsc,
669 			     struct ceph_mds_session *session,
670 			     struct ceph_msg *msg);
671 extern void ceph_queue_cap_snap(struct ceph_inode_info *ci);
672 extern int __ceph_finish_cap_snap(struct ceph_inode_info *ci,
673 				  struct ceph_cap_snap *capsnap);
674 extern void ceph_cleanup_empty_realms(struct ceph_mds_client *mdsc);
675 
676 /*
677  * a cap_snap is "pending" if it is still awaiting an in-progress
678  * sync write (that may/may not still update size, mtime, etc.).
679  */
680 static inline bool __ceph_have_pending_cap_snap(struct ceph_inode_info *ci)
681 {
682 	return !list_empty(&ci->i_cap_snaps) &&
683 		list_entry(ci->i_cap_snaps.prev, struct ceph_cap_snap,
684 			   ci_item)->writing;
685 }
686 
687 /* inode.c */
688 extern const struct inode_operations ceph_file_iops;
689 
690 extern struct inode *ceph_alloc_inode(struct super_block *sb);
691 extern void ceph_destroy_inode(struct inode *inode);
692 extern int ceph_drop_inode(struct inode *inode);
693 
694 extern struct inode *ceph_get_inode(struct super_block *sb,
695 				    struct ceph_vino vino);
696 extern struct inode *ceph_get_snapdir(struct inode *parent);
697 extern int ceph_fill_file_size(struct inode *inode, int issued,
698 			       u32 truncate_seq, u64 truncate_size, u64 size);
699 extern void ceph_fill_file_time(struct inode *inode, int issued,
700 				u64 time_warp_seq, struct timespec *ctime,
701 				struct timespec *mtime, struct timespec *atime);
702 extern int ceph_fill_trace(struct super_block *sb,
703 			   struct ceph_mds_request *req,
704 			   struct ceph_mds_session *session);
705 extern int ceph_readdir_prepopulate(struct ceph_mds_request *req,
706 				    struct ceph_mds_session *session);
707 
708 extern int ceph_inode_holds_cap(struct inode *inode, int mask);
709 
710 extern int ceph_inode_set_size(struct inode *inode, loff_t size);
711 extern void __ceph_do_pending_vmtruncate(struct inode *inode);
712 extern void ceph_queue_vmtruncate(struct inode *inode);
713 
714 extern void ceph_queue_invalidate(struct inode *inode);
715 extern void ceph_queue_writeback(struct inode *inode);
716 
717 extern int ceph_do_getattr(struct inode *inode, int mask);
718 extern int ceph_permission(struct inode *inode, int mask);
719 extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
720 extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
721 			struct kstat *stat);
722 
723 /* xattr.c */
724 extern int ceph_setxattr(struct dentry *, const char *, const void *,
725 			 size_t, int);
726 int __ceph_setxattr(struct dentry *, const char *, const void *, size_t, int);
727 ssize_t __ceph_getxattr(struct inode *, const char *, void *, size_t);
728 int __ceph_removexattr(struct dentry *, const char *);
729 extern ssize_t ceph_getxattr(struct dentry *, const char *, void *, size_t);
730 extern ssize_t ceph_listxattr(struct dentry *, char *, size_t);
731 extern int ceph_removexattr(struct dentry *, const char *);
732 extern void __ceph_build_xattrs_blob(struct ceph_inode_info *ci);
733 extern void __ceph_destroy_xattrs(struct ceph_inode_info *ci);
734 extern void __init ceph_xattr_init(void);
735 extern void ceph_xattr_exit(void);
736 
737 /* acl.c */
738 extern const struct xattr_handler *ceph_xattr_handlers[];
739 
740 #ifdef CONFIG_CEPH_FS_POSIX_ACL
741 
742 struct posix_acl *ceph_get_acl(struct inode *, int);
743 int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type);
744 int ceph_init_acl(struct dentry *, struct inode *, struct inode *);
745 
746 static inline void ceph_forget_all_cached_acls(struct inode *inode)
747 {
748        forget_all_cached_acls(inode);
749 }
750 
751 #else
752 
753 #define ceph_get_acl NULL
754 #define ceph_set_acl NULL
755 
756 static inline int ceph_init_acl(struct dentry *dentry, struct inode *inode,
757 				struct inode *dir)
758 {
759 	return 0;
760 }
761 
762 static inline int ceph_acl_chmod(struct dentry *dentry, struct inode *inode)
763 {
764 	return 0;
765 }
766 
767 static inline void ceph_forget_all_cached_acls(struct inode *inode)
768 {
769 }
770 
771 #endif
772 
773 /* caps.c */
774 extern const char *ceph_cap_string(int c);
775 extern void ceph_handle_caps(struct ceph_mds_session *session,
776 			     struct ceph_msg *msg);
777 extern struct ceph_cap *ceph_get_cap(struct ceph_mds_client *mdsc,
778 				     struct ceph_cap_reservation *ctx);
779 extern void ceph_add_cap(struct inode *inode,
780 			 struct ceph_mds_session *session, u64 cap_id,
781 			 int fmode, unsigned issued, unsigned wanted,
782 			 unsigned cap, unsigned seq, u64 realmino, int flags,
783 			 struct ceph_cap **new_cap);
784 extern void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release);
785 extern void ceph_put_cap(struct ceph_mds_client *mdsc,
786 			 struct ceph_cap *cap);
787 extern int ceph_is_any_caps(struct inode *inode);
788 
789 extern void __queue_cap_release(struct ceph_mds_session *session, u64 ino,
790 				u64 cap_id, u32 migrate_seq, u32 issue_seq);
791 extern void ceph_queue_caps_release(struct inode *inode);
792 extern int ceph_write_inode(struct inode *inode, struct writeback_control *wbc);
793 extern int ceph_fsync(struct file *file, loff_t start, loff_t end,
794 		      int datasync);
795 extern void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
796 				    struct ceph_mds_session *session);
797 extern struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci,
798 					     int mds);
799 extern int ceph_get_cap_mds(struct inode *inode);
800 extern void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps);
801 extern void ceph_put_cap_refs(struct ceph_inode_info *ci, int had);
802 extern void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
803 				       struct ceph_snap_context *snapc);
804 extern void __ceph_flush_snaps(struct ceph_inode_info *ci,
805 			       struct ceph_mds_session **psession,
806 			       int again);
807 extern void ceph_check_caps(struct ceph_inode_info *ci, int flags,
808 			    struct ceph_mds_session *session);
809 extern void ceph_check_delayed_caps(struct ceph_mds_client *mdsc);
810 extern void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc);
811 
812 extern int ceph_encode_inode_release(void **p, struct inode *inode,
813 				     int mds, int drop, int unless, int force);
814 extern int ceph_encode_dentry_release(void **p, struct dentry *dn,
815 				      int mds, int drop, int unless);
816 
817 extern int ceph_get_caps(struct ceph_inode_info *ci, int need, int want,
818 			 int *got, loff_t endoff);
819 
820 /* for counting open files by mode */
821 static inline void __ceph_get_fmode(struct ceph_inode_info *ci, int mode)
822 {
823 	ci->i_nr_by_mode[mode]++;
824 }
825 extern void ceph_put_fmode(struct ceph_inode_info *ci, int mode);
826 
827 /* addr.c */
828 extern const struct address_space_operations ceph_aops;
829 extern int ceph_mmap(struct file *file, struct vm_area_struct *vma);
830 
831 /* file.c */
832 extern const struct file_operations ceph_file_fops;
833 extern const struct address_space_operations ceph_aops;
834 
835 extern int ceph_open(struct inode *inode, struct file *file);
836 extern int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
837 			    struct file *file, unsigned flags, umode_t mode,
838 			    int *opened);
839 extern int ceph_release(struct inode *inode, struct file *filp);
840 
841 /* dir.c */
842 extern const struct file_operations ceph_dir_fops;
843 extern const struct inode_operations ceph_dir_iops;
844 extern const struct dentry_operations ceph_dentry_ops, ceph_snap_dentry_ops,
845 	ceph_snapdir_dentry_ops;
846 
847 extern int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry);
848 extern int ceph_handle_snapdir(struct ceph_mds_request *req,
849 			       struct dentry *dentry, int err);
850 extern struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
851 					 struct dentry *dentry, int err);
852 
853 extern void ceph_dentry_lru_add(struct dentry *dn);
854 extern void ceph_dentry_lru_touch(struct dentry *dn);
855 extern void ceph_dentry_lru_del(struct dentry *dn);
856 extern void ceph_invalidate_dentry_lease(struct dentry *dentry);
857 extern unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn);
858 extern struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry);
859 
860 /*
861  * our d_ops vary depending on whether the inode is live,
862  * snapshotted (read-only), or a virtual ".snap" directory.
863  */
864 int ceph_init_dentry(struct dentry *dentry);
865 
866 
867 /* ioctl.c */
868 extern long ceph_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
869 
870 /* export.c */
871 extern const struct export_operations ceph_export_ops;
872 
873 /* locks.c */
874 extern __init void ceph_flock_init(void);
875 extern int ceph_lock(struct file *file, int cmd, struct file_lock *fl);
876 extern int ceph_flock(struct file *file, int cmd, struct file_lock *fl);
877 extern void ceph_count_locks(struct inode *inode, int *p_num, int *f_num);
878 extern int ceph_encode_locks_to_buffer(struct inode *inode,
879 				       struct ceph_filelock *flocks,
880 				       int num_fcntl_locks,
881 				       int num_flock_locks);
882 extern int ceph_locks_to_pagelist(struct ceph_filelock *flocks,
883 				  struct ceph_pagelist *pagelist,
884 				  int num_fcntl_locks, int num_flock_locks);
885 extern int lock_to_ceph_filelock(struct file_lock *fl, struct ceph_filelock *c);
886 
887 /* debugfs.c */
888 extern int ceph_fs_debugfs_init(struct ceph_fs_client *client);
889 extern void ceph_fs_debugfs_cleanup(struct ceph_fs_client *client);
890 
891 #endif /* _FS_CEPH_SUPER_H */
892