xref: /openbmc/linux/fs/ceph/caps.c (revision ee6b272b)
1a8599bd8SSage Weil #include "ceph_debug.h"
2a8599bd8SSage Weil 
3a8599bd8SSage Weil #include <linux/fs.h>
4a8599bd8SSage Weil #include <linux/kernel.h>
5a8599bd8SSage Weil #include <linux/sched.h>
65a0e3ad6STejun Heo #include <linux/slab.h>
7a8599bd8SSage Weil #include <linux/vmalloc.h>
8a8599bd8SSage Weil #include <linux/wait.h>
9f1a3d572SStephen Rothwell #include <linux/writeback.h>
10a8599bd8SSage Weil 
11a8599bd8SSage Weil #include "super.h"
12a8599bd8SSage Weil #include "decode.h"
13a8599bd8SSage Weil #include "messenger.h"
14a8599bd8SSage Weil 
15a8599bd8SSage Weil /*
16a8599bd8SSage Weil  * Capability management
17a8599bd8SSage Weil  *
18a8599bd8SSage Weil  * The Ceph metadata servers control client access to inode metadata
19a8599bd8SSage Weil  * and file data by issuing capabilities, granting clients permission
20a8599bd8SSage Weil  * to read and/or write both inode field and file data to OSDs
21a8599bd8SSage Weil  * (storage nodes).  Each capability consists of a set of bits
22a8599bd8SSage Weil  * indicating which operations are allowed.
23a8599bd8SSage Weil  *
24a8599bd8SSage Weil  * If the client holds a *_SHARED cap, the client has a coherent value
25a8599bd8SSage Weil  * that can be safely read from the cached inode.
26a8599bd8SSage Weil  *
27a8599bd8SSage Weil  * In the case of a *_EXCL (exclusive) or FILE_WR capabilities, the
28a8599bd8SSage Weil  * client is allowed to change inode attributes (e.g., file size,
29a8599bd8SSage Weil  * mtime), note its dirty state in the ceph_cap, and asynchronously
30a8599bd8SSage Weil  * flush that metadata change to the MDS.
31a8599bd8SSage Weil  *
32a8599bd8SSage Weil  * In the event of a conflicting operation (perhaps by another
33a8599bd8SSage Weil  * client), the MDS will revoke the conflicting client capabilities.
34a8599bd8SSage Weil  *
35a8599bd8SSage Weil  * In order for a client to cache an inode, it must hold a capability
36a8599bd8SSage Weil  * with at least one MDS server.  When inodes are released, release
37a8599bd8SSage Weil  * notifications are batched and periodically sent en masse to the MDS
38a8599bd8SSage Weil  * cluster to release server state.
39a8599bd8SSage Weil  */
40a8599bd8SSage Weil 
41a8599bd8SSage Weil 
42a8599bd8SSage Weil /*
43a8599bd8SSage Weil  * Generate readable cap strings for debugging output.
44a8599bd8SSage Weil  */
45a8599bd8SSage Weil #define MAX_CAP_STR 20
46a8599bd8SSage Weil static char cap_str[MAX_CAP_STR][40];
47a8599bd8SSage Weil static DEFINE_SPINLOCK(cap_str_lock);
48a8599bd8SSage Weil static int last_cap_str;
49a8599bd8SSage Weil 
50a8599bd8SSage Weil static char *gcap_string(char *s, int c)
51a8599bd8SSage Weil {
52a8599bd8SSage Weil 	if (c & CEPH_CAP_GSHARED)
53a8599bd8SSage Weil 		*s++ = 's';
54a8599bd8SSage Weil 	if (c & CEPH_CAP_GEXCL)
55a8599bd8SSage Weil 		*s++ = 'x';
56a8599bd8SSage Weil 	if (c & CEPH_CAP_GCACHE)
57a8599bd8SSage Weil 		*s++ = 'c';
58a8599bd8SSage Weil 	if (c & CEPH_CAP_GRD)
59a8599bd8SSage Weil 		*s++ = 'r';
60a8599bd8SSage Weil 	if (c & CEPH_CAP_GWR)
61a8599bd8SSage Weil 		*s++ = 'w';
62a8599bd8SSage Weil 	if (c & CEPH_CAP_GBUFFER)
63a8599bd8SSage Weil 		*s++ = 'b';
64a8599bd8SSage Weil 	if (c & CEPH_CAP_GLAZYIO)
65a8599bd8SSage Weil 		*s++ = 'l';
66a8599bd8SSage Weil 	return s;
67a8599bd8SSage Weil }
68a8599bd8SSage Weil 
69a8599bd8SSage Weil const char *ceph_cap_string(int caps)
70a8599bd8SSage Weil {
71a8599bd8SSage Weil 	int i;
72a8599bd8SSage Weil 	char *s;
73a8599bd8SSage Weil 	int c;
74a8599bd8SSage Weil 
75a8599bd8SSage Weil 	spin_lock(&cap_str_lock);
76a8599bd8SSage Weil 	i = last_cap_str++;
77a8599bd8SSage Weil 	if (last_cap_str == MAX_CAP_STR)
78a8599bd8SSage Weil 		last_cap_str = 0;
79a8599bd8SSage Weil 	spin_unlock(&cap_str_lock);
80a8599bd8SSage Weil 
81a8599bd8SSage Weil 	s = cap_str[i];
82a8599bd8SSage Weil 
83a8599bd8SSage Weil 	if (caps & CEPH_CAP_PIN)
84a8599bd8SSage Weil 		*s++ = 'p';
85a8599bd8SSage Weil 
86a8599bd8SSage Weil 	c = (caps >> CEPH_CAP_SAUTH) & 3;
87a8599bd8SSage Weil 	if (c) {
88a8599bd8SSage Weil 		*s++ = 'A';
89a8599bd8SSage Weil 		s = gcap_string(s, c);
90a8599bd8SSage Weil 	}
91a8599bd8SSage Weil 
92a8599bd8SSage Weil 	c = (caps >> CEPH_CAP_SLINK) & 3;
93a8599bd8SSage Weil 	if (c) {
94a8599bd8SSage Weil 		*s++ = 'L';
95a8599bd8SSage Weil 		s = gcap_string(s, c);
96a8599bd8SSage Weil 	}
97a8599bd8SSage Weil 
98a8599bd8SSage Weil 	c = (caps >> CEPH_CAP_SXATTR) & 3;
99a8599bd8SSage Weil 	if (c) {
100a8599bd8SSage Weil 		*s++ = 'X';
101a8599bd8SSage Weil 		s = gcap_string(s, c);
102a8599bd8SSage Weil 	}
103a8599bd8SSage Weil 
104a8599bd8SSage Weil 	c = caps >> CEPH_CAP_SFILE;
105a8599bd8SSage Weil 	if (c) {
106a8599bd8SSage Weil 		*s++ = 'F';
107a8599bd8SSage Weil 		s = gcap_string(s, c);
108a8599bd8SSage Weil 	}
109a8599bd8SSage Weil 
110a8599bd8SSage Weil 	if (s == cap_str[i])
111a8599bd8SSage Weil 		*s++ = '-';
112a8599bd8SSage Weil 	*s = 0;
113a8599bd8SSage Weil 	return cap_str[i];
114a8599bd8SSage Weil }
115a8599bd8SSage Weil 
116a8599bd8SSage Weil /*
117a8599bd8SSage Weil  * Cap reservations
118a8599bd8SSage Weil  *
119a8599bd8SSage Weil  * Maintain a global pool of preallocated struct ceph_caps, referenced
120a8599bd8SSage Weil  * by struct ceph_caps_reservations.  This ensures that we preallocate
121a8599bd8SSage Weil  * memory needed to successfully process an MDS response.  (If an MDS
122a8599bd8SSage Weil  * sends us cap information and we fail to process it, we will have
123a8599bd8SSage Weil  * problems due to the client and MDS being out of sync.)
124a8599bd8SSage Weil  *
125a8599bd8SSage Weil  * Reservations are 'owned' by a ceph_cap_reservation context.
126a8599bd8SSage Weil  */
127a8599bd8SSage Weil static spinlock_t caps_list_lock;
128a8599bd8SSage Weil static struct list_head caps_list;  /* unused (reserved or unreserved) */
129a8599bd8SSage Weil static int caps_total_count;        /* total caps allocated */
130a8599bd8SSage Weil static int caps_use_count;          /* in use */
131a8599bd8SSage Weil static int caps_reserve_count;      /* unused, reserved */
132a8599bd8SSage Weil static int caps_avail_count;        /* unused, unreserved */
13385ccce43SSage Weil static int caps_min_count;          /* keep at least this many (unreserved) */
134a8599bd8SSage Weil 
135a8599bd8SSage Weil void __init ceph_caps_init(void)
136a8599bd8SSage Weil {
137a8599bd8SSage Weil 	INIT_LIST_HEAD(&caps_list);
138a8599bd8SSage Weil 	spin_lock_init(&caps_list_lock);
139a8599bd8SSage Weil }
140a8599bd8SSage Weil 
141a8599bd8SSage Weil void ceph_caps_finalize(void)
142a8599bd8SSage Weil {
143a8599bd8SSage Weil 	struct ceph_cap *cap;
144a8599bd8SSage Weil 
145a8599bd8SSage Weil 	spin_lock(&caps_list_lock);
146a8599bd8SSage Weil 	while (!list_empty(&caps_list)) {
147a8599bd8SSage Weil 		cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
148a8599bd8SSage Weil 		list_del(&cap->caps_item);
149a8599bd8SSage Weil 		kmem_cache_free(ceph_cap_cachep, cap);
150a8599bd8SSage Weil 	}
151a8599bd8SSage Weil 	caps_total_count = 0;
152a8599bd8SSage Weil 	caps_avail_count = 0;
153a8599bd8SSage Weil 	caps_use_count = 0;
154a8599bd8SSage Weil 	caps_reserve_count = 0;
15585ccce43SSage Weil 	caps_min_count = 0;
15685ccce43SSage Weil 	spin_unlock(&caps_list_lock);
15785ccce43SSage Weil }
15885ccce43SSage Weil 
15985ccce43SSage Weil void ceph_adjust_min_caps(int delta)
16085ccce43SSage Weil {
16185ccce43SSage Weil 	spin_lock(&caps_list_lock);
16285ccce43SSage Weil 	caps_min_count += delta;
16385ccce43SSage Weil 	BUG_ON(caps_min_count < 0);
164a8599bd8SSage Weil 	spin_unlock(&caps_list_lock);
165a8599bd8SSage Weil }
166a8599bd8SSage Weil 
167a8599bd8SSage Weil int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
168a8599bd8SSage Weil {
169a8599bd8SSage Weil 	int i;
170a8599bd8SSage Weil 	struct ceph_cap *cap;
171a8599bd8SSage Weil 	int have;
172a8599bd8SSage Weil 	int alloc = 0;
173a8599bd8SSage Weil 	LIST_HEAD(newcaps);
174a8599bd8SSage Weil 	int ret = 0;
175a8599bd8SSage Weil 
176a8599bd8SSage Weil 	dout("reserve caps ctx=%p need=%d\n", ctx, need);
177a8599bd8SSage Weil 
178a8599bd8SSage Weil 	/* first reserve any caps that are already allocated */
179a8599bd8SSage Weil 	spin_lock(&caps_list_lock);
180a8599bd8SSage Weil 	if (caps_avail_count >= need)
181a8599bd8SSage Weil 		have = need;
182a8599bd8SSage Weil 	else
183a8599bd8SSage Weil 		have = caps_avail_count;
184a8599bd8SSage Weil 	caps_avail_count -= have;
185a8599bd8SSage Weil 	caps_reserve_count += have;
186a8599bd8SSage Weil 	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
187a8599bd8SSage Weil 	       caps_avail_count);
188a8599bd8SSage Weil 	spin_unlock(&caps_list_lock);
189a8599bd8SSage Weil 
190a8599bd8SSage Weil 	for (i = have; i < need; i++) {
191a8599bd8SSage Weil 		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
192a8599bd8SSage Weil 		if (!cap) {
193a8599bd8SSage Weil 			ret = -ENOMEM;
194a8599bd8SSage Weil 			goto out_alloc_count;
195a8599bd8SSage Weil 		}
196a8599bd8SSage Weil 		list_add(&cap->caps_item, &newcaps);
197a8599bd8SSage Weil 		alloc++;
198a8599bd8SSage Weil 	}
199a8599bd8SSage Weil 	BUG_ON(have + alloc != need);
200a8599bd8SSage Weil 
201a8599bd8SSage Weil 	spin_lock(&caps_list_lock);
202a8599bd8SSage Weil 	caps_total_count += alloc;
203a8599bd8SSage Weil 	caps_reserve_count += alloc;
204a8599bd8SSage Weil 	list_splice(&newcaps, &caps_list);
205a8599bd8SSage Weil 
206a8599bd8SSage Weil 	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
207a8599bd8SSage Weil 	       caps_avail_count);
208a8599bd8SSage Weil 	spin_unlock(&caps_list_lock);
209a8599bd8SSage Weil 
210a8599bd8SSage Weil 	ctx->count = need;
211a8599bd8SSage Weil 	dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
212a8599bd8SSage Weil 	     ctx, caps_total_count, caps_use_count, caps_reserve_count,
213a8599bd8SSage Weil 	     caps_avail_count);
214a8599bd8SSage Weil 	return 0;
215a8599bd8SSage Weil 
216a8599bd8SSage Weil out_alloc_count:
217a8599bd8SSage Weil 	/* we didn't manage to reserve as much as we needed */
218a8599bd8SSage Weil 	pr_warning("reserve caps ctx=%p ENOMEM need=%d got=%d\n",
219a8599bd8SSage Weil 		   ctx, need, have);
220a8599bd8SSage Weil 	return ret;
221a8599bd8SSage Weil }
222a8599bd8SSage Weil 
223a8599bd8SSage Weil int ceph_unreserve_caps(struct ceph_cap_reservation *ctx)
224a8599bd8SSage Weil {
225a8599bd8SSage Weil 	dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
226a8599bd8SSage Weil 	if (ctx->count) {
227a8599bd8SSage Weil 		spin_lock(&caps_list_lock);
228a8599bd8SSage Weil 		BUG_ON(caps_reserve_count < ctx->count);
229a8599bd8SSage Weil 		caps_reserve_count -= ctx->count;
230a8599bd8SSage Weil 		caps_avail_count += ctx->count;
231a8599bd8SSage Weil 		ctx->count = 0;
232a8599bd8SSage Weil 		dout("unreserve caps %d = %d used + %d resv + %d avail\n",
233a8599bd8SSage Weil 		     caps_total_count, caps_use_count, caps_reserve_count,
234a8599bd8SSage Weil 		     caps_avail_count);
235a8599bd8SSage Weil 		BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
236a8599bd8SSage Weil 		       caps_avail_count);
237a8599bd8SSage Weil 		spin_unlock(&caps_list_lock);
238a8599bd8SSage Weil 	}
239a8599bd8SSage Weil 	return 0;
240a8599bd8SSage Weil }
241a8599bd8SSage Weil 
242a8599bd8SSage Weil static struct ceph_cap *get_cap(struct ceph_cap_reservation *ctx)
243a8599bd8SSage Weil {
244a8599bd8SSage Weil 	struct ceph_cap *cap = NULL;
245a8599bd8SSage Weil 
246a8599bd8SSage Weil 	/* temporary, until we do something about cap import/export */
247443b3760SSage Weil 	if (!ctx) {
248443b3760SSage Weil 		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
249443b3760SSage Weil 		if (cap) {
250443b3760SSage Weil 			caps_use_count++;
251443b3760SSage Weil 			caps_total_count++;
252443b3760SSage Weil 		}
253443b3760SSage Weil 		return cap;
254443b3760SSage Weil 	}
255a8599bd8SSage Weil 
256a8599bd8SSage Weil 	spin_lock(&caps_list_lock);
257a8599bd8SSage Weil 	dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
258a8599bd8SSage Weil 	     ctx, ctx->count, caps_total_count, caps_use_count,
259a8599bd8SSage Weil 	     caps_reserve_count, caps_avail_count);
260a8599bd8SSage Weil 	BUG_ON(!ctx->count);
261a8599bd8SSage Weil 	BUG_ON(ctx->count > caps_reserve_count);
262a8599bd8SSage Weil 	BUG_ON(list_empty(&caps_list));
263a8599bd8SSage Weil 
264a8599bd8SSage Weil 	ctx->count--;
265a8599bd8SSage Weil 	caps_reserve_count--;
266a8599bd8SSage Weil 	caps_use_count++;
267a8599bd8SSage Weil 
268a8599bd8SSage Weil 	cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
269a8599bd8SSage Weil 	list_del(&cap->caps_item);
270a8599bd8SSage Weil 
271a8599bd8SSage Weil 	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
272a8599bd8SSage Weil 	       caps_avail_count);
273a8599bd8SSage Weil 	spin_unlock(&caps_list_lock);
274a8599bd8SSage Weil 	return cap;
275a8599bd8SSage Weil }
276a8599bd8SSage Weil 
2777c1332b8SSage Weil void ceph_put_cap(struct ceph_cap *cap)
278a8599bd8SSage Weil {
279a8599bd8SSage Weil 	spin_lock(&caps_list_lock);
2807c1332b8SSage Weil 	dout("put_cap %p %d = %d used + %d resv + %d avail\n",
2817c1332b8SSage Weil 	     cap, caps_total_count, caps_use_count,
282a8599bd8SSage Weil 	     caps_reserve_count, caps_avail_count);
283a8599bd8SSage Weil 	caps_use_count--;
284a8599bd8SSage Weil 	/*
28585ccce43SSage Weil 	 * Keep some preallocated caps around (ceph_min_count), to
28685ccce43SSage Weil 	 * avoid lots of free/alloc churn.
287a8599bd8SSage Weil 	 */
28885ccce43SSage Weil 	if (caps_avail_count >= caps_reserve_count + caps_min_count) {
289a8599bd8SSage Weil 		caps_total_count--;
290a8599bd8SSage Weil 		kmem_cache_free(ceph_cap_cachep, cap);
291a8599bd8SSage Weil 	} else {
292a8599bd8SSage Weil 		caps_avail_count++;
293a8599bd8SSage Weil 		list_add(&cap->caps_item, &caps_list);
294a8599bd8SSage Weil 	}
295a8599bd8SSage Weil 
296a8599bd8SSage Weil 	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
297a8599bd8SSage Weil 	       caps_avail_count);
298a8599bd8SSage Weil 	spin_unlock(&caps_list_lock);
299a8599bd8SSage Weil }
300a8599bd8SSage Weil 
301a8599bd8SSage Weil void ceph_reservation_status(struct ceph_client *client,
30285ccce43SSage Weil 			     int *total, int *avail, int *used, int *reserved,
30385ccce43SSage Weil 			     int *min)
304a8599bd8SSage Weil {
305a8599bd8SSage Weil 	if (total)
306a8599bd8SSage Weil 		*total = caps_total_count;
307a8599bd8SSage Weil 	if (avail)
308a8599bd8SSage Weil 		*avail = caps_avail_count;
309a8599bd8SSage Weil 	if (used)
310a8599bd8SSage Weil 		*used = caps_use_count;
311a8599bd8SSage Weil 	if (reserved)
312a8599bd8SSage Weil 		*reserved = caps_reserve_count;
31385ccce43SSage Weil 	if (min)
31485ccce43SSage Weil 		*min = caps_min_count;
315a8599bd8SSage Weil }
316a8599bd8SSage Weil 
317a8599bd8SSage Weil /*
318a8599bd8SSage Weil  * Find ceph_cap for given mds, if any.
319a8599bd8SSage Weil  *
320a8599bd8SSage Weil  * Called with i_lock held.
321a8599bd8SSage Weil  */
322a8599bd8SSage Weil static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
323a8599bd8SSage Weil {
324a8599bd8SSage Weil 	struct ceph_cap *cap;
325a8599bd8SSage Weil 	struct rb_node *n = ci->i_caps.rb_node;
326a8599bd8SSage Weil 
327a8599bd8SSage Weil 	while (n) {
328a8599bd8SSage Weil 		cap = rb_entry(n, struct ceph_cap, ci_node);
329a8599bd8SSage Weil 		if (mds < cap->mds)
330a8599bd8SSage Weil 			n = n->rb_left;
331a8599bd8SSage Weil 		else if (mds > cap->mds)
332a8599bd8SSage Weil 			n = n->rb_right;
333a8599bd8SSage Weil 		else
334a8599bd8SSage Weil 			return cap;
335a8599bd8SSage Weil 	}
336a8599bd8SSage Weil 	return NULL;
337a8599bd8SSage Weil }
338a8599bd8SSage Weil 
339a8599bd8SSage Weil /*
34033caad32SSage Weil  * Return id of any MDS with a cap, preferably FILE_WR|BUFFER|EXCL, else -1.
341a8599bd8SSage Weil  */
342a8599bd8SSage Weil static int __ceph_get_cap_mds(struct ceph_inode_info *ci, u32 *mseq)
343a8599bd8SSage Weil {
344a8599bd8SSage Weil 	struct ceph_cap *cap;
345a8599bd8SSage Weil 	int mds = -1;
346a8599bd8SSage Weil 	struct rb_node *p;
347a8599bd8SSage Weil 
34833caad32SSage Weil 	/* prefer mds with WR|BUFFER|EXCL caps */
349a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
350a8599bd8SSage Weil 		cap = rb_entry(p, struct ceph_cap, ci_node);
351a8599bd8SSage Weil 		mds = cap->mds;
352a8599bd8SSage Weil 		if (mseq)
353a8599bd8SSage Weil 			*mseq = cap->mseq;
354a8599bd8SSage Weil 		if (cap->issued & (CEPH_CAP_FILE_WR |
355a8599bd8SSage Weil 				   CEPH_CAP_FILE_BUFFER |
356a8599bd8SSage Weil 				   CEPH_CAP_FILE_EXCL))
357a8599bd8SSage Weil 			break;
358a8599bd8SSage Weil 	}
359a8599bd8SSage Weil 	return mds;
360a8599bd8SSage Weil }
361a8599bd8SSage Weil 
362a8599bd8SSage Weil int ceph_get_cap_mds(struct inode *inode)
363a8599bd8SSage Weil {
364a8599bd8SSage Weil 	int mds;
365a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
366a8599bd8SSage Weil 	mds = __ceph_get_cap_mds(ceph_inode(inode), NULL);
367a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
368a8599bd8SSage Weil 	return mds;
369a8599bd8SSage Weil }
370a8599bd8SSage Weil 
371a8599bd8SSage Weil /*
372a8599bd8SSage Weil  * Called under i_lock.
373a8599bd8SSage Weil  */
374a8599bd8SSage Weil static void __insert_cap_node(struct ceph_inode_info *ci,
375a8599bd8SSage Weil 			      struct ceph_cap *new)
376a8599bd8SSage Weil {
377a8599bd8SSage Weil 	struct rb_node **p = &ci->i_caps.rb_node;
378a8599bd8SSage Weil 	struct rb_node *parent = NULL;
379a8599bd8SSage Weil 	struct ceph_cap *cap = NULL;
380a8599bd8SSage Weil 
381a8599bd8SSage Weil 	while (*p) {
382a8599bd8SSage Weil 		parent = *p;
383a8599bd8SSage Weil 		cap = rb_entry(parent, struct ceph_cap, ci_node);
384a8599bd8SSage Weil 		if (new->mds < cap->mds)
385a8599bd8SSage Weil 			p = &(*p)->rb_left;
386a8599bd8SSage Weil 		else if (new->mds > cap->mds)
387a8599bd8SSage Weil 			p = &(*p)->rb_right;
388a8599bd8SSage Weil 		else
389a8599bd8SSage Weil 			BUG();
390a8599bd8SSage Weil 	}
391a8599bd8SSage Weil 
392a8599bd8SSage Weil 	rb_link_node(&new->ci_node, parent, p);
393a8599bd8SSage Weil 	rb_insert_color(&new->ci_node, &ci->i_caps);
394a8599bd8SSage Weil }
395a8599bd8SSage Weil 
396a8599bd8SSage Weil /*
397a8599bd8SSage Weil  * (re)set cap hold timeouts, which control the delayed release
398a8599bd8SSage Weil  * of unused caps back to the MDS.  Should be called on cap use.
399a8599bd8SSage Weil  */
400a8599bd8SSage Weil static void __cap_set_timeouts(struct ceph_mds_client *mdsc,
401a8599bd8SSage Weil 			       struct ceph_inode_info *ci)
402a8599bd8SSage Weil {
4036b805185SSage Weil 	struct ceph_mount_args *ma = mdsc->client->mount_args;
404a8599bd8SSage Weil 
405a8599bd8SSage Weil 	ci->i_hold_caps_min = round_jiffies(jiffies +
406a8599bd8SSage Weil 					    ma->caps_wanted_delay_min * HZ);
407a8599bd8SSage Weil 	ci->i_hold_caps_max = round_jiffies(jiffies +
408a8599bd8SSage Weil 					    ma->caps_wanted_delay_max * HZ);
409a8599bd8SSage Weil 	dout("__cap_set_timeouts %p min %lu max %lu\n", &ci->vfs_inode,
410a8599bd8SSage Weil 	     ci->i_hold_caps_min - jiffies, ci->i_hold_caps_max - jiffies);
411a8599bd8SSage Weil }
412a8599bd8SSage Weil 
413a8599bd8SSage Weil /*
414a8599bd8SSage Weil  * (Re)queue cap at the end of the delayed cap release list.
415a8599bd8SSage Weil  *
416a8599bd8SSage Weil  * If I_FLUSH is set, leave the inode at the front of the list.
417a8599bd8SSage Weil  *
418a8599bd8SSage Weil  * Caller holds i_lock
419a8599bd8SSage Weil  *    -> we take mdsc->cap_delay_lock
420a8599bd8SSage Weil  */
421a8599bd8SSage Weil static void __cap_delay_requeue(struct ceph_mds_client *mdsc,
422a8599bd8SSage Weil 				struct ceph_inode_info *ci)
423a8599bd8SSage Weil {
424a8599bd8SSage Weil 	__cap_set_timeouts(mdsc, ci);
425a8599bd8SSage Weil 	dout("__cap_delay_requeue %p flags %d at %lu\n", &ci->vfs_inode,
426a8599bd8SSage Weil 	     ci->i_ceph_flags, ci->i_hold_caps_max);
427a8599bd8SSage Weil 	if (!mdsc->stopping) {
428a8599bd8SSage Weil 		spin_lock(&mdsc->cap_delay_lock);
429a8599bd8SSage Weil 		if (!list_empty(&ci->i_cap_delay_list)) {
430a8599bd8SSage Weil 			if (ci->i_ceph_flags & CEPH_I_FLUSH)
431a8599bd8SSage Weil 				goto no_change;
432a8599bd8SSage Weil 			list_del_init(&ci->i_cap_delay_list);
433a8599bd8SSage Weil 		}
434a8599bd8SSage Weil 		list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
435a8599bd8SSage Weil no_change:
436a8599bd8SSage Weil 		spin_unlock(&mdsc->cap_delay_lock);
437a8599bd8SSage Weil 	}
438a8599bd8SSage Weil }
439a8599bd8SSage Weil 
440a8599bd8SSage Weil /*
441a8599bd8SSage Weil  * Queue an inode for immediate writeback.  Mark inode with I_FLUSH,
442a8599bd8SSage Weil  * indicating we should send a cap message to flush dirty metadata
443a8599bd8SSage Weil  * asap, and move to the front of the delayed cap list.
444a8599bd8SSage Weil  */
445a8599bd8SSage Weil static void __cap_delay_requeue_front(struct ceph_mds_client *mdsc,
446a8599bd8SSage Weil 				      struct ceph_inode_info *ci)
447a8599bd8SSage Weil {
448a8599bd8SSage Weil 	dout("__cap_delay_requeue_front %p\n", &ci->vfs_inode);
449a8599bd8SSage Weil 	spin_lock(&mdsc->cap_delay_lock);
450a8599bd8SSage Weil 	ci->i_ceph_flags |= CEPH_I_FLUSH;
451a8599bd8SSage Weil 	if (!list_empty(&ci->i_cap_delay_list))
452a8599bd8SSage Weil 		list_del_init(&ci->i_cap_delay_list);
453a8599bd8SSage Weil 	list_add(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
454a8599bd8SSage Weil 	spin_unlock(&mdsc->cap_delay_lock);
455a8599bd8SSage Weil }
456a8599bd8SSage Weil 
457a8599bd8SSage Weil /*
458a8599bd8SSage Weil  * Cancel delayed work on cap.
459a8599bd8SSage Weil  *
460a8599bd8SSage Weil  * Caller must hold i_lock.
461a8599bd8SSage Weil  */
462a8599bd8SSage Weil static void __cap_delay_cancel(struct ceph_mds_client *mdsc,
463a8599bd8SSage Weil 			       struct ceph_inode_info *ci)
464a8599bd8SSage Weil {
465a8599bd8SSage Weil 	dout("__cap_delay_cancel %p\n", &ci->vfs_inode);
466a8599bd8SSage Weil 	if (list_empty(&ci->i_cap_delay_list))
467a8599bd8SSage Weil 		return;
468a8599bd8SSage Weil 	spin_lock(&mdsc->cap_delay_lock);
469a8599bd8SSage Weil 	list_del_init(&ci->i_cap_delay_list);
470a8599bd8SSage Weil 	spin_unlock(&mdsc->cap_delay_lock);
471a8599bd8SSage Weil }
472a8599bd8SSage Weil 
473a8599bd8SSage Weil /*
474a8599bd8SSage Weil  * Common issue checks for add_cap, handle_cap_grant.
475a8599bd8SSage Weil  */
476a8599bd8SSage Weil static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
477a8599bd8SSage Weil 			      unsigned issued)
478a8599bd8SSage Weil {
479a8599bd8SSage Weil 	unsigned had = __ceph_caps_issued(ci, NULL);
480a8599bd8SSage Weil 
481a8599bd8SSage Weil 	/*
482a8599bd8SSage Weil 	 * Each time we receive FILE_CACHE anew, we increment
483a8599bd8SSage Weil 	 * i_rdcache_gen.
484a8599bd8SSage Weil 	 */
4852962507cSSage Weil 	if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
4862962507cSSage Weil 	    (had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
487a8599bd8SSage Weil 		ci->i_rdcache_gen++;
488a8599bd8SSage Weil 
489a8599bd8SSage Weil 	/*
490a8599bd8SSage Weil 	 * if we are newly issued FILE_SHARED, clear I_COMPLETE; we
491a8599bd8SSage Weil 	 * don't know what happened to this directory while we didn't
492a8599bd8SSage Weil 	 * have the cap.
493a8599bd8SSage Weil 	 */
494a8599bd8SSage Weil 	if ((issued & CEPH_CAP_FILE_SHARED) &&
495a8599bd8SSage Weil 	    (had & CEPH_CAP_FILE_SHARED) == 0) {
496a8599bd8SSage Weil 		ci->i_shared_gen++;
497a8599bd8SSage Weil 		if (S_ISDIR(ci->vfs_inode.i_mode)) {
498a8599bd8SSage Weil 			dout(" marking %p NOT complete\n", &ci->vfs_inode);
499a8599bd8SSage Weil 			ci->i_ceph_flags &= ~CEPH_I_COMPLETE;
500a8599bd8SSage Weil 		}
501a8599bd8SSage Weil 	}
502a8599bd8SSage Weil }
503a8599bd8SSage Weil 
504a8599bd8SSage Weil /*
505a8599bd8SSage Weil  * Add a capability under the given MDS session.
506a8599bd8SSage Weil  *
507a8599bd8SSage Weil  * Caller should hold session snap_rwsem (read) and s_mutex.
508a8599bd8SSage Weil  *
509a8599bd8SSage Weil  * @fmode is the open file mode, if we are opening a file, otherwise
510a8599bd8SSage Weil  * it is < 0.  (This is so we can atomically add the cap and add an
511a8599bd8SSage Weil  * open file reference to it.)
512a8599bd8SSage Weil  */
513a8599bd8SSage Weil int ceph_add_cap(struct inode *inode,
514a8599bd8SSage Weil 		 struct ceph_mds_session *session, u64 cap_id,
515a8599bd8SSage Weil 		 int fmode, unsigned issued, unsigned wanted,
516a8599bd8SSage Weil 		 unsigned seq, unsigned mseq, u64 realmino, int flags,
517a8599bd8SSage Weil 		 struct ceph_cap_reservation *caps_reservation)
518a8599bd8SSage Weil {
519a8599bd8SSage Weil 	struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
520a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
521a8599bd8SSage Weil 	struct ceph_cap *new_cap = NULL;
522a8599bd8SSage Weil 	struct ceph_cap *cap;
523a8599bd8SSage Weil 	int mds = session->s_mds;
524a8599bd8SSage Weil 	int actual_wanted;
525a8599bd8SSage Weil 
526a8599bd8SSage Weil 	dout("add_cap %p mds%d cap %llx %s seq %d\n", inode,
527a8599bd8SSage Weil 	     session->s_mds, cap_id, ceph_cap_string(issued), seq);
528a8599bd8SSage Weil 
529a8599bd8SSage Weil 	/*
530a8599bd8SSage Weil 	 * If we are opening the file, include file mode wanted bits
531a8599bd8SSage Weil 	 * in wanted.
532a8599bd8SSage Weil 	 */
533a8599bd8SSage Weil 	if (fmode >= 0)
534a8599bd8SSage Weil 		wanted |= ceph_caps_for_mode(fmode);
535a8599bd8SSage Weil 
536a8599bd8SSage Weil retry:
537a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
538a8599bd8SSage Weil 	cap = __get_cap_for_mds(ci, mds);
539a8599bd8SSage Weil 	if (!cap) {
540a8599bd8SSage Weil 		if (new_cap) {
541a8599bd8SSage Weil 			cap = new_cap;
542a8599bd8SSage Weil 			new_cap = NULL;
543a8599bd8SSage Weil 		} else {
544a8599bd8SSage Weil 			spin_unlock(&inode->i_lock);
545a8599bd8SSage Weil 			new_cap = get_cap(caps_reservation);
546a8599bd8SSage Weil 			if (new_cap == NULL)
547a8599bd8SSage Weil 				return -ENOMEM;
548a8599bd8SSage Weil 			goto retry;
549a8599bd8SSage Weil 		}
550a8599bd8SSage Weil 
551a8599bd8SSage Weil 		cap->issued = 0;
552a8599bd8SSage Weil 		cap->implemented = 0;
553a8599bd8SSage Weil 		cap->mds = mds;
554a8599bd8SSage Weil 		cap->mds_wanted = 0;
555a8599bd8SSage Weil 
556a8599bd8SSage Weil 		cap->ci = ci;
557a8599bd8SSage Weil 		__insert_cap_node(ci, cap);
558a8599bd8SSage Weil 
559a8599bd8SSage Weil 		/* clear out old exporting info?  (i.e. on cap import) */
560a8599bd8SSage Weil 		if (ci->i_cap_exporting_mds == mds) {
561a8599bd8SSage Weil 			ci->i_cap_exporting_issued = 0;
562a8599bd8SSage Weil 			ci->i_cap_exporting_mseq = 0;
563a8599bd8SSage Weil 			ci->i_cap_exporting_mds = -1;
564a8599bd8SSage Weil 		}
565a8599bd8SSage Weil 
566a8599bd8SSage Weil 		/* add to session cap list */
567a8599bd8SSage Weil 		cap->session = session;
568a8599bd8SSage Weil 		spin_lock(&session->s_cap_lock);
569a8599bd8SSage Weil 		list_add_tail(&cap->session_caps, &session->s_caps);
570a8599bd8SSage Weil 		session->s_nr_caps++;
571a8599bd8SSage Weil 		spin_unlock(&session->s_cap_lock);
572a8599bd8SSage Weil 	}
573a8599bd8SSage Weil 
574a8599bd8SSage Weil 	if (!ci->i_snap_realm) {
575a8599bd8SSage Weil 		/*
576a8599bd8SSage Weil 		 * add this inode to the appropriate snap realm
577a8599bd8SSage Weil 		 */
578a8599bd8SSage Weil 		struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,
579a8599bd8SSage Weil 							       realmino);
580a8599bd8SSage Weil 		if (realm) {
581a8599bd8SSage Weil 			ceph_get_snap_realm(mdsc, realm);
582a8599bd8SSage Weil 			spin_lock(&realm->inodes_with_caps_lock);
583a8599bd8SSage Weil 			ci->i_snap_realm = realm;
584a8599bd8SSage Weil 			list_add(&ci->i_snap_realm_item,
585a8599bd8SSage Weil 				 &realm->inodes_with_caps);
586a8599bd8SSage Weil 			spin_unlock(&realm->inodes_with_caps_lock);
587a8599bd8SSage Weil 		} else {
588a8599bd8SSage Weil 			pr_err("ceph_add_cap: couldn't find snap realm %llx\n",
589a8599bd8SSage Weil 			       realmino);
590a8599bd8SSage Weil 		}
591a8599bd8SSage Weil 	}
592a8599bd8SSage Weil 
593a8599bd8SSage Weil 	__check_cap_issue(ci, cap, issued);
594a8599bd8SSage Weil 
595a8599bd8SSage Weil 	/*
596a8599bd8SSage Weil 	 * If we are issued caps we don't want, or the mds' wanted
597a8599bd8SSage Weil 	 * value appears to be off, queue a check so we'll release
598a8599bd8SSage Weil 	 * later and/or update the mds wanted value.
599a8599bd8SSage Weil 	 */
600a8599bd8SSage Weil 	actual_wanted = __ceph_caps_wanted(ci);
601a8599bd8SSage Weil 	if ((wanted & ~actual_wanted) ||
602a8599bd8SSage Weil 	    (issued & ~actual_wanted & CEPH_CAP_ANY_WR)) {
603a8599bd8SSage Weil 		dout(" issued %s, mds wanted %s, actual %s, queueing\n",
604a8599bd8SSage Weil 		     ceph_cap_string(issued), ceph_cap_string(wanted),
605a8599bd8SSage Weil 		     ceph_cap_string(actual_wanted));
606a8599bd8SSage Weil 		__cap_delay_requeue(mdsc, ci);
607a8599bd8SSage Weil 	}
608a8599bd8SSage Weil 
609a8599bd8SSage Weil 	if (flags & CEPH_CAP_FLAG_AUTH)
610a8599bd8SSage Weil 		ci->i_auth_cap = cap;
611a8599bd8SSage Weil 	else if (ci->i_auth_cap == cap)
612a8599bd8SSage Weil 		ci->i_auth_cap = NULL;
613a8599bd8SSage Weil 
614a8599bd8SSage Weil 	dout("add_cap inode %p (%llx.%llx) cap %p %s now %s seq %d mds%d\n",
615a8599bd8SSage Weil 	     inode, ceph_vinop(inode), cap, ceph_cap_string(issued),
616a8599bd8SSage Weil 	     ceph_cap_string(issued|cap->issued), seq, mds);
617a8599bd8SSage Weil 	cap->cap_id = cap_id;
618a8599bd8SSage Weil 	cap->issued = issued;
619a8599bd8SSage Weil 	cap->implemented |= issued;
620a8599bd8SSage Weil 	cap->mds_wanted |= wanted;
621a8599bd8SSage Weil 	cap->seq = seq;
622a8599bd8SSage Weil 	cap->issue_seq = seq;
623a8599bd8SSage Weil 	cap->mseq = mseq;
624685f9a5dSSage Weil 	cap->cap_gen = session->s_cap_gen;
625a8599bd8SSage Weil 
626a8599bd8SSage Weil 	if (fmode >= 0)
627a8599bd8SSage Weil 		__ceph_get_fmode(ci, fmode);
628a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
62903066f23SYehuda Sadeh 	wake_up_all(&ci->i_cap_wq);
630a8599bd8SSage Weil 	return 0;
631a8599bd8SSage Weil }
632a8599bd8SSage Weil 
633a8599bd8SSage Weil /*
634a8599bd8SSage Weil  * Return true if cap has not timed out and belongs to the current
635a8599bd8SSage Weil  * generation of the MDS session (i.e. has not gone 'stale' due to
636a8599bd8SSage Weil  * us losing touch with the mds).
637a8599bd8SSage Weil  */
638a8599bd8SSage Weil static int __cap_is_valid(struct ceph_cap *cap)
639a8599bd8SSage Weil {
640a8599bd8SSage Weil 	unsigned long ttl;
641cdac8303SSage Weil 	u32 gen;
642a8599bd8SSage Weil 
643a8599bd8SSage Weil 	spin_lock(&cap->session->s_cap_lock);
644a8599bd8SSage Weil 	gen = cap->session->s_cap_gen;
645a8599bd8SSage Weil 	ttl = cap->session->s_cap_ttl;
646a8599bd8SSage Weil 	spin_unlock(&cap->session->s_cap_lock);
647a8599bd8SSage Weil 
648685f9a5dSSage Weil 	if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {
649a8599bd8SSage Weil 		dout("__cap_is_valid %p cap %p issued %s "
650a8599bd8SSage Weil 		     "but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode,
651685f9a5dSSage Weil 		     cap, ceph_cap_string(cap->issued), cap->cap_gen, gen);
652a8599bd8SSage Weil 		return 0;
653a8599bd8SSage Weil 	}
654a8599bd8SSage Weil 
655a8599bd8SSage Weil 	return 1;
656a8599bd8SSage Weil }
657a8599bd8SSage Weil 
658a8599bd8SSage Weil /*
659a8599bd8SSage Weil  * Return set of valid cap bits issued to us.  Note that caps time
660a8599bd8SSage Weil  * out, and may be invalidated in bulk if the client session times out
661a8599bd8SSage Weil  * and session->s_cap_gen is bumped.
662a8599bd8SSage Weil  */
663a8599bd8SSage Weil int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
664a8599bd8SSage Weil {
6657af8f1e4SSage Weil 	int have = ci->i_snap_caps | ci->i_cap_exporting_issued;
666a8599bd8SSage Weil 	struct ceph_cap *cap;
667a8599bd8SSage Weil 	struct rb_node *p;
668a8599bd8SSage Weil 
669a8599bd8SSage Weil 	if (implemented)
670a8599bd8SSage Weil 		*implemented = 0;
671a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
672a8599bd8SSage Weil 		cap = rb_entry(p, struct ceph_cap, ci_node);
673a8599bd8SSage Weil 		if (!__cap_is_valid(cap))
674a8599bd8SSage Weil 			continue;
675a8599bd8SSage Weil 		dout("__ceph_caps_issued %p cap %p issued %s\n",
676a8599bd8SSage Weil 		     &ci->vfs_inode, cap, ceph_cap_string(cap->issued));
677a8599bd8SSage Weil 		have |= cap->issued;
678a8599bd8SSage Weil 		if (implemented)
679a8599bd8SSage Weil 			*implemented |= cap->implemented;
680a8599bd8SSage Weil 	}
681a8599bd8SSage Weil 	return have;
682a8599bd8SSage Weil }
683a8599bd8SSage Weil 
684a8599bd8SSage Weil /*
685a8599bd8SSage Weil  * Get cap bits issued by caps other than @ocap
686a8599bd8SSage Weil  */
687a8599bd8SSage Weil int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap)
688a8599bd8SSage Weil {
689a8599bd8SSage Weil 	int have = ci->i_snap_caps;
690a8599bd8SSage Weil 	struct ceph_cap *cap;
691a8599bd8SSage Weil 	struct rb_node *p;
692a8599bd8SSage Weil 
693a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
694a8599bd8SSage Weil 		cap = rb_entry(p, struct ceph_cap, ci_node);
695a8599bd8SSage Weil 		if (cap == ocap)
696a8599bd8SSage Weil 			continue;
697a8599bd8SSage Weil 		if (!__cap_is_valid(cap))
698a8599bd8SSage Weil 			continue;
699a8599bd8SSage Weil 		have |= cap->issued;
700a8599bd8SSage Weil 	}
701a8599bd8SSage Weil 	return have;
702a8599bd8SSage Weil }
703a8599bd8SSage Weil 
704a8599bd8SSage Weil /*
705a8599bd8SSage Weil  * Move a cap to the end of the LRU (oldest caps at list head, newest
706a8599bd8SSage Weil  * at list tail).
707a8599bd8SSage Weil  */
708a8599bd8SSage Weil static void __touch_cap(struct ceph_cap *cap)
709a8599bd8SSage Weil {
710a8599bd8SSage Weil 	struct ceph_mds_session *s = cap->session;
711a8599bd8SSage Weil 
7125dacf091SSage Weil 	spin_lock(&s->s_cap_lock);
7137c1332b8SSage Weil 	if (s->s_cap_iterator == NULL) {
714a8599bd8SSage Weil 		dout("__touch_cap %p cap %p mds%d\n", &cap->ci->vfs_inode, cap,
715a8599bd8SSage Weil 		     s->s_mds);
716a8599bd8SSage Weil 		list_move_tail(&cap->session_caps, &s->s_caps);
7175dacf091SSage Weil 	} else {
7185dacf091SSage Weil 		dout("__touch_cap %p cap %p mds%d NOP, iterating over caps\n",
7195dacf091SSage Weil 		     &cap->ci->vfs_inode, cap, s->s_mds);
7205dacf091SSage Weil 	}
721a8599bd8SSage Weil 	spin_unlock(&s->s_cap_lock);
722a8599bd8SSage Weil }
723a8599bd8SSage Weil 
724a8599bd8SSage Weil /*
725a8599bd8SSage Weil  * Check if we hold the given mask.  If so, move the cap(s) to the
726a8599bd8SSage Weil  * front of their respective LRUs.  (This is the preferred way for
727a8599bd8SSage Weil  * callers to check for caps they want.)
728a8599bd8SSage Weil  */
729a8599bd8SSage Weil int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int touch)
730a8599bd8SSage Weil {
731a8599bd8SSage Weil 	struct ceph_cap *cap;
732a8599bd8SSage Weil 	struct rb_node *p;
733a8599bd8SSage Weil 	int have = ci->i_snap_caps;
734a8599bd8SSage Weil 
735a8599bd8SSage Weil 	if ((have & mask) == mask) {
736a8599bd8SSage Weil 		dout("__ceph_caps_issued_mask %p snap issued %s"
737a8599bd8SSage Weil 		     " (mask %s)\n", &ci->vfs_inode,
738a8599bd8SSage Weil 		     ceph_cap_string(have),
739a8599bd8SSage Weil 		     ceph_cap_string(mask));
740a8599bd8SSage Weil 		return 1;
741a8599bd8SSage Weil 	}
742a8599bd8SSage Weil 
743a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
744a8599bd8SSage Weil 		cap = rb_entry(p, struct ceph_cap, ci_node);
745a8599bd8SSage Weil 		if (!__cap_is_valid(cap))
746a8599bd8SSage Weil 			continue;
747a8599bd8SSage Weil 		if ((cap->issued & mask) == mask) {
748a8599bd8SSage Weil 			dout("__ceph_caps_issued_mask %p cap %p issued %s"
749a8599bd8SSage Weil 			     " (mask %s)\n", &ci->vfs_inode, cap,
750a8599bd8SSage Weil 			     ceph_cap_string(cap->issued),
751a8599bd8SSage Weil 			     ceph_cap_string(mask));
752a8599bd8SSage Weil 			if (touch)
753a8599bd8SSage Weil 				__touch_cap(cap);
754a8599bd8SSage Weil 			return 1;
755a8599bd8SSage Weil 		}
756a8599bd8SSage Weil 
757a8599bd8SSage Weil 		/* does a combination of caps satisfy mask? */
758a8599bd8SSage Weil 		have |= cap->issued;
759a8599bd8SSage Weil 		if ((have & mask) == mask) {
760a8599bd8SSage Weil 			dout("__ceph_caps_issued_mask %p combo issued %s"
761a8599bd8SSage Weil 			     " (mask %s)\n", &ci->vfs_inode,
762a8599bd8SSage Weil 			     ceph_cap_string(cap->issued),
763a8599bd8SSage Weil 			     ceph_cap_string(mask));
764a8599bd8SSage Weil 			if (touch) {
765a8599bd8SSage Weil 				struct rb_node *q;
766a8599bd8SSage Weil 
767a8599bd8SSage Weil 				/* touch this + preceeding caps */
768a8599bd8SSage Weil 				__touch_cap(cap);
769a8599bd8SSage Weil 				for (q = rb_first(&ci->i_caps); q != p;
770a8599bd8SSage Weil 				     q = rb_next(q)) {
771a8599bd8SSage Weil 					cap = rb_entry(q, struct ceph_cap,
772a8599bd8SSage Weil 						       ci_node);
773a8599bd8SSage Weil 					if (!__cap_is_valid(cap))
774a8599bd8SSage Weil 						continue;
775a8599bd8SSage Weil 					__touch_cap(cap);
776a8599bd8SSage Weil 				}
777a8599bd8SSage Weil 			}
778a8599bd8SSage Weil 			return 1;
779a8599bd8SSage Weil 		}
780a8599bd8SSage Weil 	}
781a8599bd8SSage Weil 
782a8599bd8SSage Weil 	return 0;
783a8599bd8SSage Weil }
784a8599bd8SSage Weil 
785a8599bd8SSage Weil /*
786a8599bd8SSage Weil  * Return true if mask caps are currently being revoked by an MDS.
787a8599bd8SSage Weil  */
788a8599bd8SSage Weil int ceph_caps_revoking(struct ceph_inode_info *ci, int mask)
789a8599bd8SSage Weil {
790a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
791a8599bd8SSage Weil 	struct ceph_cap *cap;
792a8599bd8SSage Weil 	struct rb_node *p;
793a8599bd8SSage Weil 	int ret = 0;
794a8599bd8SSage Weil 
795a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
796a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
797a8599bd8SSage Weil 		cap = rb_entry(p, struct ceph_cap, ci_node);
798a8599bd8SSage Weil 		if (__cap_is_valid(cap) &&
799a8599bd8SSage Weil 		    (cap->implemented & ~cap->issued & mask)) {
800a8599bd8SSage Weil 			ret = 1;
801a8599bd8SSage Weil 			break;
802a8599bd8SSage Weil 		}
803a8599bd8SSage Weil 	}
804a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
805a8599bd8SSage Weil 	dout("ceph_caps_revoking %p %s = %d\n", inode,
806a8599bd8SSage Weil 	     ceph_cap_string(mask), ret);
807a8599bd8SSage Weil 	return ret;
808a8599bd8SSage Weil }
809a8599bd8SSage Weil 
810a8599bd8SSage Weil int __ceph_caps_used(struct ceph_inode_info *ci)
811a8599bd8SSage Weil {
812a8599bd8SSage Weil 	int used = 0;
813a8599bd8SSage Weil 	if (ci->i_pin_ref)
814a8599bd8SSage Weil 		used |= CEPH_CAP_PIN;
815a8599bd8SSage Weil 	if (ci->i_rd_ref)
816a8599bd8SSage Weil 		used |= CEPH_CAP_FILE_RD;
817a8599bd8SSage Weil 	if (ci->i_rdcache_ref || ci->i_rdcache_gen)
818a8599bd8SSage Weil 		used |= CEPH_CAP_FILE_CACHE;
819a8599bd8SSage Weil 	if (ci->i_wr_ref)
820a8599bd8SSage Weil 		used |= CEPH_CAP_FILE_WR;
821a8599bd8SSage Weil 	if (ci->i_wrbuffer_ref)
822a8599bd8SSage Weil 		used |= CEPH_CAP_FILE_BUFFER;
823a8599bd8SSage Weil 	return used;
824a8599bd8SSage Weil }
825a8599bd8SSage Weil 
826a8599bd8SSage Weil /*
827a8599bd8SSage Weil  * wanted, by virtue of open file modes
828a8599bd8SSage Weil  */
829a8599bd8SSage Weil int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
830a8599bd8SSage Weil {
831a8599bd8SSage Weil 	int want = 0;
832a8599bd8SSage Weil 	int mode;
83333caad32SSage Weil 	for (mode = 0; mode < CEPH_FILE_MODE_NUM; mode++)
834a8599bd8SSage Weil 		if (ci->i_nr_by_mode[mode])
835a8599bd8SSage Weil 			want |= ceph_caps_for_mode(mode);
836a8599bd8SSage Weil 	return want;
837a8599bd8SSage Weil }
838a8599bd8SSage Weil 
839a8599bd8SSage Weil /*
840a8599bd8SSage Weil  * Return caps we have registered with the MDS(s) as 'wanted'.
841a8599bd8SSage Weil  */
842a8599bd8SSage Weil int __ceph_caps_mds_wanted(struct ceph_inode_info *ci)
843a8599bd8SSage Weil {
844a8599bd8SSage Weil 	struct ceph_cap *cap;
845a8599bd8SSage Weil 	struct rb_node *p;
846a8599bd8SSage Weil 	int mds_wanted = 0;
847a8599bd8SSage Weil 
848a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
849a8599bd8SSage Weil 		cap = rb_entry(p, struct ceph_cap, ci_node);
850a8599bd8SSage Weil 		if (!__cap_is_valid(cap))
851a8599bd8SSage Weil 			continue;
852a8599bd8SSage Weil 		mds_wanted |= cap->mds_wanted;
853a8599bd8SSage Weil 	}
854a8599bd8SSage Weil 	return mds_wanted;
855a8599bd8SSage Weil }
856a8599bd8SSage Weil 
857a8599bd8SSage Weil /*
858a8599bd8SSage Weil  * called under i_lock
859a8599bd8SSage Weil  */
860a8599bd8SSage Weil static int __ceph_is_any_caps(struct ceph_inode_info *ci)
861a8599bd8SSage Weil {
862a8599bd8SSage Weil 	return !RB_EMPTY_ROOT(&ci->i_caps) || ci->i_cap_exporting_mds >= 0;
863a8599bd8SSage Weil }
864a8599bd8SSage Weil 
865a8599bd8SSage Weil /*
866f818a736SSage Weil  * Remove a cap.  Take steps to deal with a racing iterate_session_caps.
867f818a736SSage Weil  *
868a6369741SSage Weil  * caller should hold i_lock.
869a6369741SSage Weil  * caller will not hold session s_mutex if called from destroy_inode.
870a8599bd8SSage Weil  */
8717c1332b8SSage Weil void __ceph_remove_cap(struct ceph_cap *cap)
872a8599bd8SSage Weil {
873a8599bd8SSage Weil 	struct ceph_mds_session *session = cap->session;
874a8599bd8SSage Weil 	struct ceph_inode_info *ci = cap->ci;
875640ef79dSCheng Renquan 	struct ceph_mds_client *mdsc =
876640ef79dSCheng Renquan 		&ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
877f818a736SSage Weil 	int removed = 0;
878a8599bd8SSage Weil 
879a8599bd8SSage Weil 	dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
880a8599bd8SSage Weil 
8817c1332b8SSage Weil 	/* remove from session list */
8827c1332b8SSage Weil 	spin_lock(&session->s_cap_lock);
8837c1332b8SSage Weil 	if (session->s_cap_iterator == cap) {
8847c1332b8SSage Weil 		/* not yet, we are iterating over this very cap */
8857c1332b8SSage Weil 		dout("__ceph_remove_cap  delaying %p removal from session %p\n",
8867c1332b8SSage Weil 		     cap, cap->session);
8877c1332b8SSage Weil 	} else {
8887c1332b8SSage Weil 		list_del_init(&cap->session_caps);
8897c1332b8SSage Weil 		session->s_nr_caps--;
8907c1332b8SSage Weil 		cap->session = NULL;
891f818a736SSage Weil 		removed = 1;
8927c1332b8SSage Weil 	}
893f818a736SSage Weil 	/* protect backpointer with s_cap_lock: see iterate_session_caps */
894f818a736SSage Weil 	cap->ci = NULL;
8957c1332b8SSage Weil 	spin_unlock(&session->s_cap_lock);
8967c1332b8SSage Weil 
897f818a736SSage Weil 	/* remove from inode list */
898f818a736SSage Weil 	rb_erase(&cap->ci_node, &ci->i_caps);
899f818a736SSage Weil 	if (ci->i_auth_cap == cap)
900f818a736SSage Weil 		ci->i_auth_cap = NULL;
901f818a736SSage Weil 
902f818a736SSage Weil 	if (removed)
9037c1332b8SSage Weil 		ceph_put_cap(cap);
904a8599bd8SSage Weil 
905a8599bd8SSage Weil 	if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
906a8599bd8SSage Weil 		struct ceph_snap_realm *realm = ci->i_snap_realm;
907a8599bd8SSage Weil 		spin_lock(&realm->inodes_with_caps_lock);
908a8599bd8SSage Weil 		list_del_init(&ci->i_snap_realm_item);
909a8599bd8SSage Weil 		ci->i_snap_realm_counter++;
910a8599bd8SSage Weil 		ci->i_snap_realm = NULL;
911a8599bd8SSage Weil 		spin_unlock(&realm->inodes_with_caps_lock);
912a8599bd8SSage Weil 		ceph_put_snap_realm(mdsc, realm);
913a8599bd8SSage Weil 	}
914a8599bd8SSage Weil 	if (!__ceph_is_any_real_caps(ci))
915a8599bd8SSage Weil 		__cap_delay_cancel(mdsc, ci);
916a8599bd8SSage Weil }
917a8599bd8SSage Weil 
918a8599bd8SSage Weil /*
919a8599bd8SSage Weil  * Build and send a cap message to the given MDS.
920a8599bd8SSage Weil  *
921a8599bd8SSage Weil  * Caller should be holding s_mutex.
922a8599bd8SSage Weil  */
923a8599bd8SSage Weil static int send_cap_msg(struct ceph_mds_session *session,
924a8599bd8SSage Weil 			u64 ino, u64 cid, int op,
925a8599bd8SSage Weil 			int caps, int wanted, int dirty,
926a8599bd8SSage Weil 			u32 seq, u64 flush_tid, u32 issue_seq, u32 mseq,
927a8599bd8SSage Weil 			u64 size, u64 max_size,
928a8599bd8SSage Weil 			struct timespec *mtime, struct timespec *atime,
929a8599bd8SSage Weil 			u64 time_warp_seq,
930a8599bd8SSage Weil 			uid_t uid, gid_t gid, mode_t mode,
931a8599bd8SSage Weil 			u64 xattr_version,
932a8599bd8SSage Weil 			struct ceph_buffer *xattrs_buf,
933a8599bd8SSage Weil 			u64 follows)
934a8599bd8SSage Weil {
935a8599bd8SSage Weil 	struct ceph_mds_caps *fc;
936a8599bd8SSage Weil 	struct ceph_msg *msg;
937a8599bd8SSage Weil 
938a8599bd8SSage Weil 	dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
939a8599bd8SSage Weil 	     " seq %u/%u mseq %u follows %lld size %llu/%llu"
940a8599bd8SSage Weil 	     " xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(op),
941a8599bd8SSage Weil 	     cid, ino, ceph_cap_string(caps), ceph_cap_string(wanted),
942a8599bd8SSage Weil 	     ceph_cap_string(dirty),
943a8599bd8SSage Weil 	     seq, issue_seq, mseq, follows, size, max_size,
944a8599bd8SSage Weil 	     xattr_version, xattrs_buf ? (int)xattrs_buf->vec.iov_len : 0);
945a8599bd8SSage Weil 
94634d23762SYehuda Sadeh 	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), GFP_NOFS);
947a79832f2SSage Weil 	if (!msg)
948a79832f2SSage Weil 		return -ENOMEM;
949a8599bd8SSage Weil 
9506df058c0SSage Weil 	msg->hdr.tid = cpu_to_le64(flush_tid);
951a8599bd8SSage Weil 
9526df058c0SSage Weil 	fc = msg->front.iov_base;
953a8599bd8SSage Weil 	memset(fc, 0, sizeof(*fc));
954a8599bd8SSage Weil 
955a8599bd8SSage Weil 	fc->cap_id = cpu_to_le64(cid);
956a8599bd8SSage Weil 	fc->op = cpu_to_le32(op);
957a8599bd8SSage Weil 	fc->seq = cpu_to_le32(seq);
958a8599bd8SSage Weil 	fc->issue_seq = cpu_to_le32(issue_seq);
959a8599bd8SSage Weil 	fc->migrate_seq = cpu_to_le32(mseq);
960a8599bd8SSage Weil 	fc->caps = cpu_to_le32(caps);
961a8599bd8SSage Weil 	fc->wanted = cpu_to_le32(wanted);
962a8599bd8SSage Weil 	fc->dirty = cpu_to_le32(dirty);
963a8599bd8SSage Weil 	fc->ino = cpu_to_le64(ino);
964a8599bd8SSage Weil 	fc->snap_follows = cpu_to_le64(follows);
965a8599bd8SSage Weil 
966a8599bd8SSage Weil 	fc->size = cpu_to_le64(size);
967a8599bd8SSage Weil 	fc->max_size = cpu_to_le64(max_size);
968a8599bd8SSage Weil 	if (mtime)
969a8599bd8SSage Weil 		ceph_encode_timespec(&fc->mtime, mtime);
970a8599bd8SSage Weil 	if (atime)
971a8599bd8SSage Weil 		ceph_encode_timespec(&fc->atime, atime);
972a8599bd8SSage Weil 	fc->time_warp_seq = cpu_to_le32(time_warp_seq);
973a8599bd8SSage Weil 
974a8599bd8SSage Weil 	fc->uid = cpu_to_le32(uid);
975a8599bd8SSage Weil 	fc->gid = cpu_to_le32(gid);
976a8599bd8SSage Weil 	fc->mode = cpu_to_le32(mode);
977a8599bd8SSage Weil 
978a8599bd8SSage Weil 	fc->xattr_version = cpu_to_le64(xattr_version);
979a8599bd8SSage Weil 	if (xattrs_buf) {
980a8599bd8SSage Weil 		msg->middle = ceph_buffer_get(xattrs_buf);
981a8599bd8SSage Weil 		fc->xattr_len = cpu_to_le32(xattrs_buf->vec.iov_len);
982a8599bd8SSage Weil 		msg->hdr.middle_len = cpu_to_le32(xattrs_buf->vec.iov_len);
983a8599bd8SSage Weil 	}
984a8599bd8SSage Weil 
985a8599bd8SSage Weil 	ceph_con_send(&session->s_con, msg);
986a8599bd8SSage Weil 	return 0;
987a8599bd8SSage Weil }
988a8599bd8SSage Weil 
9893d7ded4dSSage Weil static void __queue_cap_release(struct ceph_mds_session *session,
9903d7ded4dSSage Weil 				u64 ino, u64 cap_id, u32 migrate_seq,
9913d7ded4dSSage Weil 				u32 issue_seq)
9923d7ded4dSSage Weil {
9933d7ded4dSSage Weil 	struct ceph_msg *msg;
9943d7ded4dSSage Weil 	struct ceph_mds_cap_release *head;
9953d7ded4dSSage Weil 	struct ceph_mds_cap_item *item;
9963d7ded4dSSage Weil 
9973d7ded4dSSage Weil 	spin_lock(&session->s_cap_lock);
9983d7ded4dSSage Weil 	BUG_ON(!session->s_num_cap_releases);
9993d7ded4dSSage Weil 	msg = list_first_entry(&session->s_cap_releases,
10003d7ded4dSSage Weil 			       struct ceph_msg, list_head);
10013d7ded4dSSage Weil 
10023d7ded4dSSage Weil 	dout(" adding %llx release to mds%d msg %p (%d left)\n",
10033d7ded4dSSage Weil 	     ino, session->s_mds, msg, session->s_num_cap_releases);
10043d7ded4dSSage Weil 
10053d7ded4dSSage Weil 	BUG_ON(msg->front.iov_len + sizeof(*item) > PAGE_CACHE_SIZE);
10063d7ded4dSSage Weil 	head = msg->front.iov_base;
10073d7ded4dSSage Weil 	head->num = cpu_to_le32(le32_to_cpu(head->num) + 1);
10083d7ded4dSSage Weil 	item = msg->front.iov_base + msg->front.iov_len;
10093d7ded4dSSage Weil 	item->ino = cpu_to_le64(ino);
10103d7ded4dSSage Weil 	item->cap_id = cpu_to_le64(cap_id);
10113d7ded4dSSage Weil 	item->migrate_seq = cpu_to_le32(migrate_seq);
10123d7ded4dSSage Weil 	item->seq = cpu_to_le32(issue_seq);
10133d7ded4dSSage Weil 
10143d7ded4dSSage Weil 	session->s_num_cap_releases--;
10153d7ded4dSSage Weil 
10163d7ded4dSSage Weil 	msg->front.iov_len += sizeof(*item);
10173d7ded4dSSage Weil 	if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
10183d7ded4dSSage Weil 		dout(" release msg %p full\n", msg);
10193d7ded4dSSage Weil 		list_move_tail(&msg->list_head, &session->s_cap_releases_done);
10203d7ded4dSSage Weil 	} else {
10213d7ded4dSSage Weil 		dout(" release msg %p at %d/%d (%d)\n", msg,
10223d7ded4dSSage Weil 		     (int)le32_to_cpu(head->num),
10233d7ded4dSSage Weil 		     (int)CEPH_CAPS_PER_RELEASE,
10243d7ded4dSSage Weil 		     (int)msg->front.iov_len);
10253d7ded4dSSage Weil 	}
10263d7ded4dSSage Weil 	spin_unlock(&session->s_cap_lock);
10273d7ded4dSSage Weil }
10283d7ded4dSSage Weil 
1029a8599bd8SSage Weil /*
1030a6369741SSage Weil  * Queue cap releases when an inode is dropped from our cache.  Since
1031a6369741SSage Weil  * inode is about to be destroyed, there is no need for i_lock.
1032a8599bd8SSage Weil  */
1033a8599bd8SSage Weil void ceph_queue_caps_release(struct inode *inode)
1034a8599bd8SSage Weil {
1035a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
1036a8599bd8SSage Weil 	struct rb_node *p;
1037a8599bd8SSage Weil 
1038a8599bd8SSage Weil 	p = rb_first(&ci->i_caps);
1039a8599bd8SSage Weil 	while (p) {
1040a8599bd8SSage Weil 		struct ceph_cap *cap = rb_entry(p, struct ceph_cap, ci_node);
1041a8599bd8SSage Weil 		struct ceph_mds_session *session = cap->session;
1042a8599bd8SSage Weil 
10433d7ded4dSSage Weil 		__queue_cap_release(session, ceph_ino(inode), cap->cap_id,
10443d7ded4dSSage Weil 				    cap->mseq, cap->issue_seq);
1045a8599bd8SSage Weil 		p = rb_next(p);
10467c1332b8SSage Weil 		__ceph_remove_cap(cap);
1047a8599bd8SSage Weil 	}
1048a8599bd8SSage Weil }
1049a8599bd8SSage Weil 
1050a8599bd8SSage Weil /*
1051a8599bd8SSage Weil  * Send a cap msg on the given inode.  Update our caps state, then
1052a8599bd8SSage Weil  * drop i_lock and send the message.
1053a8599bd8SSage Weil  *
1054a8599bd8SSage Weil  * Make note of max_size reported/requested from mds, revoked caps
1055a8599bd8SSage Weil  * that have now been implemented.
1056a8599bd8SSage Weil  *
1057a8599bd8SSage Weil  * Make half-hearted attempt ot to invalidate page cache if we are
1058a8599bd8SSage Weil  * dropping RDCACHE.  Note that this will leave behind locked pages
1059a8599bd8SSage Weil  * that we'll then need to deal with elsewhere.
1060a8599bd8SSage Weil  *
1061a8599bd8SSage Weil  * Return non-zero if delayed release, or we experienced an error
1062a8599bd8SSage Weil  * such that the caller should requeue + retry later.
1063a8599bd8SSage Weil  *
1064a8599bd8SSage Weil  * called with i_lock, then drops it.
1065a8599bd8SSage Weil  * caller should hold snap_rwsem (read), s_mutex.
1066a8599bd8SSage Weil  */
1067a8599bd8SSage Weil static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
1068a8599bd8SSage Weil 		      int op, int used, int want, int retain, int flushing,
1069a8599bd8SSage Weil 		      unsigned *pflush_tid)
1070a8599bd8SSage Weil 	__releases(cap->ci->vfs_inode->i_lock)
1071a8599bd8SSage Weil {
1072a8599bd8SSage Weil 	struct ceph_inode_info *ci = cap->ci;
1073a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
1074a8599bd8SSage Weil 	u64 cap_id = cap->cap_id;
107568c28323SSage Weil 	int held, revoking, dropping, keep;
1076a8599bd8SSage Weil 	u64 seq, issue_seq, mseq, time_warp_seq, follows;
1077a8599bd8SSage Weil 	u64 size, max_size;
1078a8599bd8SSage Weil 	struct timespec mtime, atime;
1079a8599bd8SSage Weil 	int wake = 0;
1080a8599bd8SSage Weil 	mode_t mode;
1081a8599bd8SSage Weil 	uid_t uid;
1082a8599bd8SSage Weil 	gid_t gid;
1083a8599bd8SSage Weil 	struct ceph_mds_session *session;
1084a8599bd8SSage Weil 	u64 xattr_version = 0;
1085a8599bd8SSage Weil 	int delayed = 0;
1086a8599bd8SSage Weil 	u64 flush_tid = 0;
1087a8599bd8SSage Weil 	int i;
1088a8599bd8SSage Weil 	int ret;
1089a8599bd8SSage Weil 
109068c28323SSage Weil 	held = cap->issued | cap->implemented;
109168c28323SSage Weil 	revoking = cap->implemented & ~cap->issued;
109268c28323SSage Weil 	retain &= ~revoking;
109368c28323SSage Weil 	dropping = cap->issued & ~retain;
109468c28323SSage Weil 
1095a8599bd8SSage Weil 	dout("__send_cap %p cap %p session %p %s -> %s (revoking %s)\n",
1096a8599bd8SSage Weil 	     inode, cap, cap->session,
1097a8599bd8SSage Weil 	     ceph_cap_string(held), ceph_cap_string(held & retain),
1098a8599bd8SSage Weil 	     ceph_cap_string(revoking));
1099a8599bd8SSage Weil 	BUG_ON((retain & CEPH_CAP_PIN) == 0);
1100a8599bd8SSage Weil 
1101a8599bd8SSage Weil 	session = cap->session;
1102a8599bd8SSage Weil 
1103a8599bd8SSage Weil 	/* don't release wanted unless we've waited a bit. */
1104a8599bd8SSage Weil 	if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1105a8599bd8SSage Weil 	    time_before(jiffies, ci->i_hold_caps_min)) {
1106a8599bd8SSage Weil 		dout(" delaying issued %s -> %s, wanted %s -> %s on send\n",
1107a8599bd8SSage Weil 		     ceph_cap_string(cap->issued),
1108a8599bd8SSage Weil 		     ceph_cap_string(cap->issued & retain),
1109a8599bd8SSage Weil 		     ceph_cap_string(cap->mds_wanted),
1110a8599bd8SSage Weil 		     ceph_cap_string(want));
1111a8599bd8SSage Weil 		want |= cap->mds_wanted;
1112a8599bd8SSage Weil 		retain |= cap->issued;
1113a8599bd8SSage Weil 		delayed = 1;
1114a8599bd8SSage Weil 	}
1115a8599bd8SSage Weil 	ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH);
1116a8599bd8SSage Weil 
1117a8599bd8SSage Weil 	cap->issued &= retain;  /* drop bits we don't want */
1118a8599bd8SSage Weil 	if (cap->implemented & ~cap->issued) {
1119a8599bd8SSage Weil 		/*
1120a8599bd8SSage Weil 		 * Wake up any waiters on wanted -> needed transition.
1121a8599bd8SSage Weil 		 * This is due to the weird transition from buffered
1122a8599bd8SSage Weil 		 * to sync IO... we need to flush dirty pages _before_
1123a8599bd8SSage Weil 		 * allowing sync writes to avoid reordering.
1124a8599bd8SSage Weil 		 */
1125a8599bd8SSage Weil 		wake = 1;
1126a8599bd8SSage Weil 	}
1127a8599bd8SSage Weil 	cap->implemented &= cap->issued | used;
1128a8599bd8SSage Weil 	cap->mds_wanted = want;
1129a8599bd8SSage Weil 
1130a8599bd8SSage Weil 	if (flushing) {
1131a8599bd8SSage Weil 		/*
1132a8599bd8SSage Weil 		 * assign a tid for flush operations so we can avoid
1133a8599bd8SSage Weil 		 * flush1 -> dirty1 -> flush2 -> flushack1 -> mark
1134a8599bd8SSage Weil 		 * clean type races.  track latest tid for every bit
1135a8599bd8SSage Weil 		 * so we can handle flush AxFw, flush Fw, and have the
1136a8599bd8SSage Weil 		 * first ack clean Ax.
1137a8599bd8SSage Weil 		 */
1138a8599bd8SSage Weil 		flush_tid = ++ci->i_cap_flush_last_tid;
1139a8599bd8SSage Weil 		if (pflush_tid)
1140a8599bd8SSage Weil 			*pflush_tid = flush_tid;
1141a8599bd8SSage Weil 		dout(" cap_flush_tid %d\n", (int)flush_tid);
1142a8599bd8SSage Weil 		for (i = 0; i < CEPH_CAP_BITS; i++)
1143a8599bd8SSage Weil 			if (flushing & (1 << i))
1144a8599bd8SSage Weil 				ci->i_cap_flush_tid[i] = flush_tid;
1145a8599bd8SSage Weil 	}
1146a8599bd8SSage Weil 
1147a8599bd8SSage Weil 	keep = cap->implemented;
1148a8599bd8SSage Weil 	seq = cap->seq;
1149a8599bd8SSage Weil 	issue_seq = cap->issue_seq;
1150a8599bd8SSage Weil 	mseq = cap->mseq;
1151a8599bd8SSage Weil 	size = inode->i_size;
1152a8599bd8SSage Weil 	ci->i_reported_size = size;
1153a8599bd8SSage Weil 	max_size = ci->i_wanted_max_size;
1154a8599bd8SSage Weil 	ci->i_requested_max_size = max_size;
1155a8599bd8SSage Weil 	mtime = inode->i_mtime;
1156a8599bd8SSage Weil 	atime = inode->i_atime;
1157a8599bd8SSage Weil 	time_warp_seq = ci->i_time_warp_seq;
1158a8599bd8SSage Weil 	follows = ci->i_snap_realm->cached_context->seq;
1159a8599bd8SSage Weil 	uid = inode->i_uid;
1160a8599bd8SSage Weil 	gid = inode->i_gid;
1161a8599bd8SSage Weil 	mode = inode->i_mode;
1162a8599bd8SSage Weil 
1163a8599bd8SSage Weil 	if (dropping & CEPH_CAP_XATTR_EXCL) {
1164a8599bd8SSage Weil 		__ceph_build_xattrs_blob(ci);
1165a8599bd8SSage Weil 		xattr_version = ci->i_xattrs.version + 1;
1166a8599bd8SSage Weil 	}
1167a8599bd8SSage Weil 
1168a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
1169a8599bd8SSage Weil 
1170a8599bd8SSage Weil 	ret = send_cap_msg(session, ceph_vino(inode).ino, cap_id,
1171a8599bd8SSage Weil 		op, keep, want, flushing, seq, flush_tid, issue_seq, mseq,
1172a8599bd8SSage Weil 		size, max_size, &mtime, &atime, time_warp_seq,
1173a8599bd8SSage Weil 		uid, gid, mode,
1174a8599bd8SSage Weil 		xattr_version,
1175a8599bd8SSage Weil 		(flushing & CEPH_CAP_XATTR_EXCL) ? ci->i_xattrs.blob : NULL,
1176a8599bd8SSage Weil 		follows);
1177a8599bd8SSage Weil 	if (ret < 0) {
1178a8599bd8SSage Weil 		dout("error sending cap msg, must requeue %p\n", inode);
1179a8599bd8SSage Weil 		delayed = 1;
1180a8599bd8SSage Weil 	}
1181a8599bd8SSage Weil 
1182a8599bd8SSage Weil 	if (wake)
118303066f23SYehuda Sadeh 		wake_up_all(&ci->i_cap_wq);
1184a8599bd8SSage Weil 
1185a8599bd8SSage Weil 	return delayed;
1186a8599bd8SSage Weil }
1187a8599bd8SSage Weil 
1188a8599bd8SSage Weil /*
1189a8599bd8SSage Weil  * When a snapshot is taken, clients accumulate dirty metadata on
1190a8599bd8SSage Weil  * inodes with capabilities in ceph_cap_snaps to describe the file
1191a8599bd8SSage Weil  * state at the time the snapshot was taken.  This must be flushed
1192a8599bd8SSage Weil  * asynchronously back to the MDS once sync writes complete and dirty
1193a8599bd8SSage Weil  * data is written out.
1194a8599bd8SSage Weil  *
1195a8599bd8SSage Weil  * Called under i_lock.  Takes s_mutex as needed.
1196a8599bd8SSage Weil  */
1197a8599bd8SSage Weil void __ceph_flush_snaps(struct ceph_inode_info *ci,
1198a8599bd8SSage Weil 			struct ceph_mds_session **psession)
1199a8599bd8SSage Weil {
1200a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
1201a8599bd8SSage Weil 	int mds;
1202a8599bd8SSage Weil 	struct ceph_cap_snap *capsnap;
1203a8599bd8SSage Weil 	u32 mseq;
1204a8599bd8SSage Weil 	struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
1205a8599bd8SSage Weil 	struct ceph_mds_session *session = NULL; /* if session != NULL, we hold
1206a8599bd8SSage Weil 						    session->s_mutex */
1207a8599bd8SSage Weil 	u64 next_follows = 0;  /* keep track of how far we've gotten through the
1208a8599bd8SSage Weil 			     i_cap_snaps list, and skip these entries next time
1209a8599bd8SSage Weil 			     around to avoid an infinite loop */
1210a8599bd8SSage Weil 
1211a8599bd8SSage Weil 	if (psession)
1212a8599bd8SSage Weil 		session = *psession;
1213a8599bd8SSage Weil 
1214a8599bd8SSage Weil 	dout("__flush_snaps %p\n", inode);
1215a8599bd8SSage Weil retry:
1216a8599bd8SSage Weil 	list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
1217a8599bd8SSage Weil 		/* avoid an infiniute loop after retry */
1218a8599bd8SSage Weil 		if (capsnap->follows < next_follows)
1219a8599bd8SSage Weil 			continue;
1220a8599bd8SSage Weil 		/*
1221a8599bd8SSage Weil 		 * we need to wait for sync writes to complete and for dirty
1222a8599bd8SSage Weil 		 * pages to be written out.
1223a8599bd8SSage Weil 		 */
1224a8599bd8SSage Weil 		if (capsnap->dirty_pages || capsnap->writing)
1225a8599bd8SSage Weil 			continue;
1226a8599bd8SSage Weil 
1227819ccbfaSSage Weil 		/*
1228819ccbfaSSage Weil 		 * if cap writeback already occurred, we should have dropped
1229819ccbfaSSage Weil 		 * the capsnap in ceph_put_wrbuffer_cap_refs.
1230819ccbfaSSage Weil 		 */
1231819ccbfaSSage Weil 		BUG_ON(capsnap->dirty == 0);
1232819ccbfaSSage Weil 
1233a8599bd8SSage Weil 		/* pick mds, take s_mutex */
1234a8599bd8SSage Weil 		mds = __ceph_get_cap_mds(ci, &mseq);
1235a8599bd8SSage Weil 		if (session && session->s_mds != mds) {
1236a8599bd8SSage Weil 			dout("oops, wrong session %p mutex\n", session);
1237a8599bd8SSage Weil 			mutex_unlock(&session->s_mutex);
1238a8599bd8SSage Weil 			ceph_put_mds_session(session);
1239a8599bd8SSage Weil 			session = NULL;
1240a8599bd8SSage Weil 		}
1241a8599bd8SSage Weil 		if (!session) {
1242a8599bd8SSage Weil 			spin_unlock(&inode->i_lock);
1243a8599bd8SSage Weil 			mutex_lock(&mdsc->mutex);
1244a8599bd8SSage Weil 			session = __ceph_lookup_mds_session(mdsc, mds);
1245a8599bd8SSage Weil 			mutex_unlock(&mdsc->mutex);
1246a8599bd8SSage Weil 			if (session) {
1247a8599bd8SSage Weil 				dout("inverting session/ino locks on %p\n",
1248a8599bd8SSage Weil 				     session);
1249a8599bd8SSage Weil 				mutex_lock(&session->s_mutex);
1250a8599bd8SSage Weil 			}
1251a8599bd8SSage Weil 			/*
1252a8599bd8SSage Weil 			 * if session == NULL, we raced against a cap
1253a8599bd8SSage Weil 			 * deletion.  retry, and we'll get a better
1254a8599bd8SSage Weil 			 * @mds value next time.
1255a8599bd8SSage Weil 			 */
1256a8599bd8SSage Weil 			spin_lock(&inode->i_lock);
1257a8599bd8SSage Weil 			goto retry;
1258a8599bd8SSage Weil 		}
1259a8599bd8SSage Weil 
1260a8599bd8SSage Weil 		capsnap->flush_tid = ++ci->i_cap_flush_last_tid;
1261a8599bd8SSage Weil 		atomic_inc(&capsnap->nref);
1262a8599bd8SSage Weil 		if (!list_empty(&capsnap->flushing_item))
1263a8599bd8SSage Weil 			list_del_init(&capsnap->flushing_item);
1264a8599bd8SSage Weil 		list_add_tail(&capsnap->flushing_item,
1265a8599bd8SSage Weil 			      &session->s_cap_snaps_flushing);
1266a8599bd8SSage Weil 		spin_unlock(&inode->i_lock);
1267a8599bd8SSage Weil 
1268a8599bd8SSage Weil 		dout("flush_snaps %p cap_snap %p follows %lld size %llu\n",
1269a8599bd8SSage Weil 		     inode, capsnap, next_follows, capsnap->size);
1270a8599bd8SSage Weil 		send_cap_msg(session, ceph_vino(inode).ino, 0,
1271a8599bd8SSage Weil 			     CEPH_CAP_OP_FLUSHSNAP, capsnap->issued, 0,
1272a8599bd8SSage Weil 			     capsnap->dirty, 0, capsnap->flush_tid, 0, mseq,
1273a8599bd8SSage Weil 			     capsnap->size, 0,
1274a8599bd8SSage Weil 			     &capsnap->mtime, &capsnap->atime,
1275a8599bd8SSage Weil 			     capsnap->time_warp_seq,
1276a8599bd8SSage Weil 			     capsnap->uid, capsnap->gid, capsnap->mode,
1277a8599bd8SSage Weil 			     0, NULL,
1278a8599bd8SSage Weil 			     capsnap->follows);
1279a8599bd8SSage Weil 
1280a8599bd8SSage Weil 		next_follows = capsnap->follows + 1;
1281a8599bd8SSage Weil 		ceph_put_cap_snap(capsnap);
1282a8599bd8SSage Weil 
1283a8599bd8SSage Weil 		spin_lock(&inode->i_lock);
1284a8599bd8SSage Weil 		goto retry;
1285a8599bd8SSage Weil 	}
1286a8599bd8SSage Weil 
1287a8599bd8SSage Weil 	/* we flushed them all; remove this inode from the queue */
1288a8599bd8SSage Weil 	spin_lock(&mdsc->snap_flush_lock);
1289a8599bd8SSage Weil 	list_del_init(&ci->i_snap_flush_item);
1290a8599bd8SSage Weil 	spin_unlock(&mdsc->snap_flush_lock);
1291a8599bd8SSage Weil 
1292a8599bd8SSage Weil 	if (psession)
1293a8599bd8SSage Weil 		*psession = session;
1294a8599bd8SSage Weil 	else if (session) {
1295a8599bd8SSage Weil 		mutex_unlock(&session->s_mutex);
1296a8599bd8SSage Weil 		ceph_put_mds_session(session);
1297a8599bd8SSage Weil 	}
1298a8599bd8SSage Weil }
1299a8599bd8SSage Weil 
1300a8599bd8SSage Weil static void ceph_flush_snaps(struct ceph_inode_info *ci)
1301a8599bd8SSage Weil {
1302a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
1303a8599bd8SSage Weil 
1304a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
1305a8599bd8SSage Weil 	__ceph_flush_snaps(ci, NULL);
1306a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
1307a8599bd8SSage Weil }
1308a8599bd8SSage Weil 
1309a8599bd8SSage Weil /*
131076e3b390SSage Weil  * Mark caps dirty.  If inode is newly dirty, add to the global dirty
131176e3b390SSage Weil  * list.
131276e3b390SSage Weil  */
131376e3b390SSage Weil void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
131476e3b390SSage Weil {
1315640ef79dSCheng Renquan 	struct ceph_mds_client *mdsc =
1316640ef79dSCheng Renquan 		&ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
131776e3b390SSage Weil 	struct inode *inode = &ci->vfs_inode;
131876e3b390SSage Weil 	int was = ci->i_dirty_caps;
131976e3b390SSage Weil 	int dirty = 0;
132076e3b390SSage Weil 
132176e3b390SSage Weil 	dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode,
132276e3b390SSage Weil 	     ceph_cap_string(mask), ceph_cap_string(was),
132376e3b390SSage Weil 	     ceph_cap_string(was | mask));
132476e3b390SSage Weil 	ci->i_dirty_caps |= mask;
132576e3b390SSage Weil 	if (was == 0) {
132676e3b390SSage Weil 		dout(" inode %p now dirty\n", &ci->vfs_inode);
132776e3b390SSage Weil 		BUG_ON(!list_empty(&ci->i_dirty_item));
132876e3b390SSage Weil 		spin_lock(&mdsc->cap_dirty_lock);
132976e3b390SSage Weil 		list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
133076e3b390SSage Weil 		spin_unlock(&mdsc->cap_dirty_lock);
133176e3b390SSage Weil 		if (ci->i_flushing_caps == 0) {
133276e3b390SSage Weil 			igrab(inode);
133376e3b390SSage Weil 			dirty |= I_DIRTY_SYNC;
133476e3b390SSage Weil 		}
133576e3b390SSage Weil 	}
133676e3b390SSage Weil 	BUG_ON(list_empty(&ci->i_dirty_item));
133776e3b390SSage Weil 	if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
133876e3b390SSage Weil 	    (mask & CEPH_CAP_FILE_BUFFER))
133976e3b390SSage Weil 		dirty |= I_DIRTY_DATASYNC;
134076e3b390SSage Weil 	if (dirty)
134176e3b390SSage Weil 		__mark_inode_dirty(inode, dirty);
134276e3b390SSage Weil 	__cap_delay_requeue(mdsc, ci);
134376e3b390SSage Weil }
134476e3b390SSage Weil 
134576e3b390SSage Weil /*
1346a8599bd8SSage Weil  * Add dirty inode to the flushing list.  Assigned a seq number so we
1347a8599bd8SSage Weil  * can wait for caps to flush without starving.
1348cdc35f96SSage Weil  *
1349cdc35f96SSage Weil  * Called under i_lock.
1350a8599bd8SSage Weil  */
1351cdc35f96SSage Weil static int __mark_caps_flushing(struct inode *inode,
1352a8599bd8SSage Weil 				 struct ceph_mds_session *session)
1353a8599bd8SSage Weil {
1354640ef79dSCheng Renquan 	struct ceph_mds_client *mdsc = &ceph_sb_to_client(inode->i_sb)->mdsc;
1355a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
1356cdc35f96SSage Weil 	int flushing;
1357a8599bd8SSage Weil 
1358cdc35f96SSage Weil 	BUG_ON(ci->i_dirty_caps == 0);
1359a8599bd8SSage Weil 	BUG_ON(list_empty(&ci->i_dirty_item));
1360cdc35f96SSage Weil 
1361cdc35f96SSage Weil 	flushing = ci->i_dirty_caps;
1362cdc35f96SSage Weil 	dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n",
1363cdc35f96SSage Weil 	     ceph_cap_string(flushing),
1364cdc35f96SSage Weil 	     ceph_cap_string(ci->i_flushing_caps),
1365cdc35f96SSage Weil 	     ceph_cap_string(ci->i_flushing_caps | flushing));
1366cdc35f96SSage Weil 	ci->i_flushing_caps |= flushing;
1367cdc35f96SSage Weil 	ci->i_dirty_caps = 0;
1368afcdaea3SSage Weil 	dout(" inode %p now !dirty\n", inode);
1369cdc35f96SSage Weil 
1370a8599bd8SSage Weil 	spin_lock(&mdsc->cap_dirty_lock);
1371cdc35f96SSage Weil 	list_del_init(&ci->i_dirty_item);
1372afcdaea3SSage Weil 
1373afcdaea3SSage Weil 	ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
1374afcdaea3SSage Weil 	if (list_empty(&ci->i_flushing_item)) {
1375a8599bd8SSage Weil 		list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1376a8599bd8SSage Weil 		mdsc->num_cap_flushing++;
1377afcdaea3SSage Weil 		dout(" inode %p now flushing seq %lld\n", inode,
1378afcdaea3SSage Weil 		     ci->i_cap_flush_seq);
1379afcdaea3SSage Weil 	} else {
1380afcdaea3SSage Weil 		list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1381afcdaea3SSage Weil 		dout(" inode %p now flushing (more) seq %lld\n", inode,
1382a8599bd8SSage Weil 		     ci->i_cap_flush_seq);
1383a8599bd8SSage Weil 	}
1384a8599bd8SSage Weil 	spin_unlock(&mdsc->cap_dirty_lock);
1385cdc35f96SSage Weil 
1386cdc35f96SSage Weil 	return flushing;
1387a8599bd8SSage Weil }
1388a8599bd8SSage Weil 
1389a8599bd8SSage Weil /*
13905ecad6fdSSage Weil  * try to invalidate mapping pages without blocking.
13915ecad6fdSSage Weil  */
13925ecad6fdSSage Weil static int mapping_is_empty(struct address_space *mapping)
13935ecad6fdSSage Weil {
13945ecad6fdSSage Weil 	struct page *page = find_get_page(mapping, 0);
13955ecad6fdSSage Weil 
13965ecad6fdSSage Weil 	if (!page)
13975ecad6fdSSage Weil 		return 1;
13985ecad6fdSSage Weil 
13995ecad6fdSSage Weil 	put_page(page);
14005ecad6fdSSage Weil 	return 0;
14015ecad6fdSSage Weil }
14025ecad6fdSSage Weil 
14035ecad6fdSSage Weil static int try_nonblocking_invalidate(struct inode *inode)
14045ecad6fdSSage Weil {
14055ecad6fdSSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
14065ecad6fdSSage Weil 	u32 invalidating_gen = ci->i_rdcache_gen;
14075ecad6fdSSage Weil 
14085ecad6fdSSage Weil 	spin_unlock(&inode->i_lock);
14095ecad6fdSSage Weil 	invalidate_mapping_pages(&inode->i_data, 0, -1);
14105ecad6fdSSage Weil 	spin_lock(&inode->i_lock);
14115ecad6fdSSage Weil 
14125ecad6fdSSage Weil 	if (mapping_is_empty(&inode->i_data) &&
14135ecad6fdSSage Weil 	    invalidating_gen == ci->i_rdcache_gen) {
14145ecad6fdSSage Weil 		/* success. */
14155ecad6fdSSage Weil 		dout("try_nonblocking_invalidate %p success\n", inode);
14165ecad6fdSSage Weil 		ci->i_rdcache_gen = 0;
14175ecad6fdSSage Weil 		ci->i_rdcache_revoking = 0;
14185ecad6fdSSage Weil 		return 0;
14195ecad6fdSSage Weil 	}
14205ecad6fdSSage Weil 	dout("try_nonblocking_invalidate %p failed\n", inode);
14215ecad6fdSSage Weil 	return -1;
14225ecad6fdSSage Weil }
14235ecad6fdSSage Weil 
14245ecad6fdSSage Weil /*
1425a8599bd8SSage Weil  * Swiss army knife function to examine currently used and wanted
1426a8599bd8SSage Weil  * versus held caps.  Release, flush, ack revoked caps to mds as
1427a8599bd8SSage Weil  * appropriate.
1428a8599bd8SSage Weil  *
1429a8599bd8SSage Weil  *  CHECK_CAPS_NODELAY - caller is delayed work and we should not delay
1430a8599bd8SSage Weil  *    cap release further.
1431a8599bd8SSage Weil  *  CHECK_CAPS_AUTHONLY - we should only check the auth cap
1432a8599bd8SSage Weil  *  CHECK_CAPS_FLUSH - we should flush any dirty caps immediately, without
1433a8599bd8SSage Weil  *    further delay.
1434a8599bd8SSage Weil  */
1435a8599bd8SSage Weil void ceph_check_caps(struct ceph_inode_info *ci, int flags,
1436a8599bd8SSage Weil 		     struct ceph_mds_session *session)
1437cdc2ce05SSage Weil 	__releases(session->s_mutex)
1438a8599bd8SSage Weil {
1439a8599bd8SSage Weil 	struct ceph_client *client = ceph_inode_to_client(&ci->vfs_inode);
1440a8599bd8SSage Weil 	struct ceph_mds_client *mdsc = &client->mdsc;
1441a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
1442a8599bd8SSage Weil 	struct ceph_cap *cap;
1443a8599bd8SSage Weil 	int file_wanted, used;
1444a8599bd8SSage Weil 	int took_snap_rwsem = 0;             /* true if mdsc->snap_rwsem held */
1445cbd03635SSage Weil 	int issued, implemented, want, retain, revoking, flushing = 0;
1446a8599bd8SSage Weil 	int mds = -1;   /* keep track of how far we've gone through i_caps list
1447a8599bd8SSage Weil 			   to avoid an infinite loop on retry */
1448a8599bd8SSage Weil 	struct rb_node *p;
1449a8599bd8SSage Weil 	int tried_invalidate = 0;
1450a8599bd8SSage Weil 	int delayed = 0, sent = 0, force_requeue = 0, num;
1451cbd03635SSage Weil 	int queue_invalidate = 0;
1452a8599bd8SSage Weil 	int is_delayed = flags & CHECK_CAPS_NODELAY;
1453a8599bd8SSage Weil 
1454a8599bd8SSage Weil 	/* if we are unmounting, flush any unused caps immediately. */
1455a8599bd8SSage Weil 	if (mdsc->stopping)
1456a8599bd8SSage Weil 		is_delayed = 1;
1457a8599bd8SSage Weil 
1458a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
1459a8599bd8SSage Weil 
1460a8599bd8SSage Weil 	if (ci->i_ceph_flags & CEPH_I_FLUSH)
1461a8599bd8SSage Weil 		flags |= CHECK_CAPS_FLUSH;
1462a8599bd8SSage Weil 
1463a8599bd8SSage Weil 	/* flush snaps first time around only */
1464a8599bd8SSage Weil 	if (!list_empty(&ci->i_cap_snaps))
1465a8599bd8SSage Weil 		__ceph_flush_snaps(ci, &session);
1466a8599bd8SSage Weil 	goto retry_locked;
1467a8599bd8SSage Weil retry:
1468a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
1469a8599bd8SSage Weil retry_locked:
1470a8599bd8SSage Weil 	file_wanted = __ceph_caps_file_wanted(ci);
1471a8599bd8SSage Weil 	used = __ceph_caps_used(ci);
1472a8599bd8SSage Weil 	want = file_wanted | used;
1473cbd03635SSage Weil 	issued = __ceph_caps_issued(ci, &implemented);
1474cbd03635SSage Weil 	revoking = implemented & ~issued;
1475a8599bd8SSage Weil 
1476a8599bd8SSage Weil 	retain = want | CEPH_CAP_PIN;
1477a8599bd8SSage Weil 	if (!mdsc->stopping && inode->i_nlink > 0) {
1478a8599bd8SSage Weil 		if (want) {
1479a8599bd8SSage Weil 			retain |= CEPH_CAP_ANY;       /* be greedy */
1480a8599bd8SSage Weil 		} else {
1481a8599bd8SSage Weil 			retain |= CEPH_CAP_ANY_SHARED;
1482a8599bd8SSage Weil 			/*
1483a8599bd8SSage Weil 			 * keep RD only if we didn't have the file open RW,
1484a8599bd8SSage Weil 			 * because then the mds would revoke it anyway to
1485a8599bd8SSage Weil 			 * journal max_size=0.
1486a8599bd8SSage Weil 			 */
1487a8599bd8SSage Weil 			if (ci->i_max_size == 0)
1488a8599bd8SSage Weil 				retain |= CEPH_CAP_ANY_RD;
1489a8599bd8SSage Weil 		}
1490a8599bd8SSage Weil 	}
1491a8599bd8SSage Weil 
1492a8599bd8SSage Weil 	dout("check_caps %p file_want %s used %s dirty %s flushing %s"
1493cbd03635SSage Weil 	     " issued %s revoking %s retain %s %s%s%s\n", inode,
1494a8599bd8SSage Weil 	     ceph_cap_string(file_wanted),
1495a8599bd8SSage Weil 	     ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps),
1496a8599bd8SSage Weil 	     ceph_cap_string(ci->i_flushing_caps),
1497cbd03635SSage Weil 	     ceph_cap_string(issued), ceph_cap_string(revoking),
1498a8599bd8SSage Weil 	     ceph_cap_string(retain),
1499a8599bd8SSage Weil 	     (flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "",
1500a8599bd8SSage Weil 	     (flags & CHECK_CAPS_NODELAY) ? " NODELAY" : "",
1501a8599bd8SSage Weil 	     (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "");
1502a8599bd8SSage Weil 
1503a8599bd8SSage Weil 	/*
1504a8599bd8SSage Weil 	 * If we no longer need to hold onto old our caps, and we may
1505a8599bd8SSage Weil 	 * have cached pages, but don't want them, then try to invalidate.
1506a8599bd8SSage Weil 	 * If we fail, it's because pages are locked.... try again later.
1507a8599bd8SSage Weil 	 */
1508a8599bd8SSage Weil 	if ((!is_delayed || mdsc->stopping) &&
1509a8599bd8SSage Weil 	    ci->i_wrbuffer_ref == 0 &&               /* no dirty pages... */
1510a8599bd8SSage Weil 	    ci->i_rdcache_gen &&                     /* may have cached pages */
1511cbd03635SSage Weil 	    (file_wanted == 0 ||                     /* no open files */
15122962507cSSage Weil 	     (revoking & (CEPH_CAP_FILE_CACHE|
15132962507cSSage Weil 			  CEPH_CAP_FILE_LAZYIO))) && /*  or revoking cache */
1514a8599bd8SSage Weil 	    !tried_invalidate) {
1515a8599bd8SSage Weil 		dout("check_caps trying to invalidate on %p\n", inode);
15165ecad6fdSSage Weil 		if (try_nonblocking_invalidate(inode) < 0) {
15172962507cSSage Weil 			if (revoking & (CEPH_CAP_FILE_CACHE|
15182962507cSSage Weil 					CEPH_CAP_FILE_LAZYIO)) {
1519cbd03635SSage Weil 				dout("check_caps queuing invalidate\n");
1520cbd03635SSage Weil 				queue_invalidate = 1;
1521cbd03635SSage Weil 				ci->i_rdcache_revoking = ci->i_rdcache_gen;
1522a8599bd8SSage Weil 			} else {
1523a8599bd8SSage Weil 				dout("check_caps failed to invalidate pages\n");
1524a8599bd8SSage Weil 				/* we failed to invalidate pages.  check these
1525a8599bd8SSage Weil 				   caps again later. */
1526a8599bd8SSage Weil 				force_requeue = 1;
1527a8599bd8SSage Weil 				__cap_set_timeouts(mdsc, ci);
1528a8599bd8SSage Weil 			}
15295ecad6fdSSage Weil 		}
1530a8599bd8SSage Weil 		tried_invalidate = 1;
1531a8599bd8SSage Weil 		goto retry_locked;
1532a8599bd8SSage Weil 	}
1533a8599bd8SSage Weil 
1534a8599bd8SSage Weil 	num = 0;
1535a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
1536a8599bd8SSage Weil 		cap = rb_entry(p, struct ceph_cap, ci_node);
1537a8599bd8SSage Weil 		num++;
1538a8599bd8SSage Weil 
1539a8599bd8SSage Weil 		/* avoid looping forever */
1540a8599bd8SSage Weil 		if (mds >= cap->mds ||
1541a8599bd8SSage Weil 		    ((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap))
1542a8599bd8SSage Weil 			continue;
1543a8599bd8SSage Weil 
1544a8599bd8SSage Weil 		/* NOTE: no side-effects allowed, until we take s_mutex */
1545a8599bd8SSage Weil 
1546a8599bd8SSage Weil 		revoking = cap->implemented & ~cap->issued;
1547a8599bd8SSage Weil 		if (revoking)
1548a8599bd8SSage Weil 			dout(" mds%d revoking %s\n", cap->mds,
1549a8599bd8SSage Weil 			     ceph_cap_string(revoking));
1550a8599bd8SSage Weil 
1551a8599bd8SSage Weil 		if (cap == ci->i_auth_cap &&
1552a8599bd8SSage Weil 		    (cap->issued & CEPH_CAP_FILE_WR)) {
1553a8599bd8SSage Weil 			/* request larger max_size from MDS? */
1554a8599bd8SSage Weil 			if (ci->i_wanted_max_size > ci->i_max_size &&
1555a8599bd8SSage Weil 			    ci->i_wanted_max_size > ci->i_requested_max_size) {
1556a8599bd8SSage Weil 				dout("requesting new max_size\n");
1557a8599bd8SSage Weil 				goto ack;
1558a8599bd8SSage Weil 			}
1559a8599bd8SSage Weil 
1560a8599bd8SSage Weil 			/* approaching file_max? */
1561a8599bd8SSage Weil 			if ((inode->i_size << 1) >= ci->i_max_size &&
1562a8599bd8SSage Weil 			    (ci->i_reported_size << 1) < ci->i_max_size) {
1563a8599bd8SSage Weil 				dout("i_size approaching max_size\n");
1564a8599bd8SSage Weil 				goto ack;
1565a8599bd8SSage Weil 			}
1566a8599bd8SSage Weil 		}
1567a8599bd8SSage Weil 		/* flush anything dirty? */
1568a8599bd8SSage Weil 		if (cap == ci->i_auth_cap && (flags & CHECK_CAPS_FLUSH) &&
1569a8599bd8SSage Weil 		    ci->i_dirty_caps) {
1570a8599bd8SSage Weil 			dout("flushing dirty caps\n");
1571a8599bd8SSage Weil 			goto ack;
1572a8599bd8SSage Weil 		}
1573a8599bd8SSage Weil 
1574a8599bd8SSage Weil 		/* completed revocation? going down and there are no caps? */
1575a8599bd8SSage Weil 		if (revoking && (revoking & used) == 0) {
1576a8599bd8SSage Weil 			dout("completed revocation of %s\n",
1577a8599bd8SSage Weil 			     ceph_cap_string(cap->implemented & ~cap->issued));
1578a8599bd8SSage Weil 			goto ack;
1579a8599bd8SSage Weil 		}
1580a8599bd8SSage Weil 
1581a8599bd8SSage Weil 		/* want more caps from mds? */
1582a8599bd8SSage Weil 		if (want & ~(cap->mds_wanted | cap->issued))
1583a8599bd8SSage Weil 			goto ack;
1584a8599bd8SSage Weil 
1585a8599bd8SSage Weil 		/* things we might delay */
1586a8599bd8SSage Weil 		if ((cap->issued & ~retain) == 0 &&
1587a8599bd8SSage Weil 		    cap->mds_wanted == want)
1588a8599bd8SSage Weil 			continue;     /* nope, all good */
1589a8599bd8SSage Weil 
1590a8599bd8SSage Weil 		if (is_delayed)
1591a8599bd8SSage Weil 			goto ack;
1592a8599bd8SSage Weil 
1593a8599bd8SSage Weil 		/* delay? */
1594a8599bd8SSage Weil 		if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1595a8599bd8SSage Weil 		    time_before(jiffies, ci->i_hold_caps_max)) {
1596a8599bd8SSage Weil 			dout(" delaying issued %s -> %s, wanted %s -> %s\n",
1597a8599bd8SSage Weil 			     ceph_cap_string(cap->issued),
1598a8599bd8SSage Weil 			     ceph_cap_string(cap->issued & retain),
1599a8599bd8SSage Weil 			     ceph_cap_string(cap->mds_wanted),
1600a8599bd8SSage Weil 			     ceph_cap_string(want));
1601a8599bd8SSage Weil 			delayed++;
1602a8599bd8SSage Weil 			continue;
1603a8599bd8SSage Weil 		}
1604a8599bd8SSage Weil 
1605a8599bd8SSage Weil ack:
1606e9964c10SSage Weil 		if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1607e9964c10SSage Weil 			dout(" skipping %p I_NOFLUSH set\n", inode);
1608e9964c10SSage Weil 			continue;
1609e9964c10SSage Weil 		}
1610e9964c10SSage Weil 
1611a8599bd8SSage Weil 		if (session && session != cap->session) {
1612a8599bd8SSage Weil 			dout("oops, wrong session %p mutex\n", session);
1613a8599bd8SSage Weil 			mutex_unlock(&session->s_mutex);
1614a8599bd8SSage Weil 			session = NULL;
1615a8599bd8SSage Weil 		}
1616a8599bd8SSage Weil 		if (!session) {
1617a8599bd8SSage Weil 			session = cap->session;
1618a8599bd8SSage Weil 			if (mutex_trylock(&session->s_mutex) == 0) {
1619a8599bd8SSage Weil 				dout("inverting session/ino locks on %p\n",
1620a8599bd8SSage Weil 				     session);
1621a8599bd8SSage Weil 				spin_unlock(&inode->i_lock);
1622a8599bd8SSage Weil 				if (took_snap_rwsem) {
1623a8599bd8SSage Weil 					up_read(&mdsc->snap_rwsem);
1624a8599bd8SSage Weil 					took_snap_rwsem = 0;
1625a8599bd8SSage Weil 				}
1626a8599bd8SSage Weil 				mutex_lock(&session->s_mutex);
1627a8599bd8SSage Weil 				goto retry;
1628a8599bd8SSage Weil 			}
1629a8599bd8SSage Weil 		}
1630a8599bd8SSage Weil 		/* take snap_rwsem after session mutex */
1631a8599bd8SSage Weil 		if (!took_snap_rwsem) {
1632a8599bd8SSage Weil 			if (down_read_trylock(&mdsc->snap_rwsem) == 0) {
1633a8599bd8SSage Weil 				dout("inverting snap/in locks on %p\n",
1634a8599bd8SSage Weil 				     inode);
1635a8599bd8SSage Weil 				spin_unlock(&inode->i_lock);
1636a8599bd8SSage Weil 				down_read(&mdsc->snap_rwsem);
1637a8599bd8SSage Weil 				took_snap_rwsem = 1;
1638a8599bd8SSage Weil 				goto retry;
1639a8599bd8SSage Weil 			}
1640a8599bd8SSage Weil 			took_snap_rwsem = 1;
1641a8599bd8SSage Weil 		}
1642a8599bd8SSage Weil 
1643cdc35f96SSage Weil 		if (cap == ci->i_auth_cap && ci->i_dirty_caps)
1644cdc35f96SSage Weil 			flushing = __mark_caps_flushing(inode, session);
1645a8599bd8SSage Weil 
1646a8599bd8SSage Weil 		mds = cap->mds;  /* remember mds, so we don't repeat */
1647a8599bd8SSage Weil 		sent++;
1648a8599bd8SSage Weil 
1649a8599bd8SSage Weil 		/* __send_cap drops i_lock */
1650a8599bd8SSage Weil 		delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, used, want,
1651a8599bd8SSage Weil 				      retain, flushing, NULL);
1652a8599bd8SSage Weil 		goto retry; /* retake i_lock and restart our cap scan. */
1653a8599bd8SSage Weil 	}
1654a8599bd8SSage Weil 
1655a8599bd8SSage Weil 	/*
1656a8599bd8SSage Weil 	 * Reschedule delayed caps release if we delayed anything,
1657a8599bd8SSage Weil 	 * otherwise cancel.
1658a8599bd8SSage Weil 	 */
1659a8599bd8SSage Weil 	if (delayed && is_delayed)
1660a8599bd8SSage Weil 		force_requeue = 1;   /* __send_cap delayed release; requeue */
1661a8599bd8SSage Weil 	if (!delayed && !is_delayed)
1662a8599bd8SSage Weil 		__cap_delay_cancel(mdsc, ci);
1663a8599bd8SSage Weil 	else if (!is_delayed || force_requeue)
1664a8599bd8SSage Weil 		__cap_delay_requeue(mdsc, ci);
1665a8599bd8SSage Weil 
1666a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
1667a8599bd8SSage Weil 
1668cbd03635SSage Weil 	if (queue_invalidate)
16693c6f6b79SSage Weil 		ceph_queue_invalidate(inode);
1670cbd03635SSage Weil 
1671cdc2ce05SSage Weil 	if (session)
1672a8599bd8SSage Weil 		mutex_unlock(&session->s_mutex);
1673a8599bd8SSage Weil 	if (took_snap_rwsem)
1674a8599bd8SSage Weil 		up_read(&mdsc->snap_rwsem);
1675a8599bd8SSage Weil }
1676a8599bd8SSage Weil 
1677a8599bd8SSage Weil /*
1678a8599bd8SSage Weil  * Try to flush dirty caps back to the auth mds.
1679a8599bd8SSage Weil  */
1680a8599bd8SSage Weil static int try_flush_caps(struct inode *inode, struct ceph_mds_session *session,
1681a8599bd8SSage Weil 			  unsigned *flush_tid)
1682a8599bd8SSage Weil {
1683640ef79dSCheng Renquan 	struct ceph_mds_client *mdsc = &ceph_sb_to_client(inode->i_sb)->mdsc;
1684a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
1685a8599bd8SSage Weil 	int unlock_session = session ? 0 : 1;
1686a8599bd8SSage Weil 	int flushing = 0;
1687a8599bd8SSage Weil 
1688a8599bd8SSage Weil retry:
1689a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
1690e9964c10SSage Weil 	if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1691e9964c10SSage Weil 		dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode);
1692e9964c10SSage Weil 		goto out;
1693e9964c10SSage Weil 	}
1694a8599bd8SSage Weil 	if (ci->i_dirty_caps && ci->i_auth_cap) {
1695a8599bd8SSage Weil 		struct ceph_cap *cap = ci->i_auth_cap;
1696a8599bd8SSage Weil 		int used = __ceph_caps_used(ci);
1697a8599bd8SSage Weil 		int want = __ceph_caps_wanted(ci);
1698a8599bd8SSage Weil 		int delayed;
1699a8599bd8SSage Weil 
1700a8599bd8SSage Weil 		if (!session) {
1701a8599bd8SSage Weil 			spin_unlock(&inode->i_lock);
1702a8599bd8SSage Weil 			session = cap->session;
1703a8599bd8SSage Weil 			mutex_lock(&session->s_mutex);
1704a8599bd8SSage Weil 			goto retry;
1705a8599bd8SSage Weil 		}
1706a8599bd8SSage Weil 		BUG_ON(session != cap->session);
1707a8599bd8SSage Weil 		if (cap->session->s_state < CEPH_MDS_SESSION_OPEN)
1708a8599bd8SSage Weil 			goto out;
1709a8599bd8SSage Weil 
1710cdc35f96SSage Weil 		flushing = __mark_caps_flushing(inode, session);
1711a8599bd8SSage Weil 
1712a8599bd8SSage Weil 		/* __send_cap drops i_lock */
1713a8599bd8SSage Weil 		delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, used, want,
1714a8599bd8SSage Weil 				     cap->issued | cap->implemented, flushing,
1715a8599bd8SSage Weil 				     flush_tid);
1716a8599bd8SSage Weil 		if (!delayed)
1717a8599bd8SSage Weil 			goto out_unlocked;
1718a8599bd8SSage Weil 
1719a8599bd8SSage Weil 		spin_lock(&inode->i_lock);
1720a8599bd8SSage Weil 		__cap_delay_requeue(mdsc, ci);
1721a8599bd8SSage Weil 	}
1722a8599bd8SSage Weil out:
1723a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
1724a8599bd8SSage Weil out_unlocked:
1725a8599bd8SSage Weil 	if (session && unlock_session)
1726a8599bd8SSage Weil 		mutex_unlock(&session->s_mutex);
1727a8599bd8SSage Weil 	return flushing;
1728a8599bd8SSage Weil }
1729a8599bd8SSage Weil 
1730a8599bd8SSage Weil /*
1731a8599bd8SSage Weil  * Return true if we've flushed caps through the given flush_tid.
1732a8599bd8SSage Weil  */
1733a8599bd8SSage Weil static int caps_are_flushed(struct inode *inode, unsigned tid)
1734a8599bd8SSage Weil {
1735a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
1736a5ee751cSDan Carpenter 	int i, ret = 1;
1737a8599bd8SSage Weil 
1738a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
1739a8599bd8SSage Weil 	for (i = 0; i < CEPH_CAP_BITS; i++)
1740a8599bd8SSage Weil 		if ((ci->i_flushing_caps & (1 << i)) &&
1741a8599bd8SSage Weil 		    ci->i_cap_flush_tid[i] <= tid) {
1742a8599bd8SSage Weil 			/* still flushing this bit */
1743a8599bd8SSage Weil 			ret = 0;
1744a8599bd8SSage Weil 			break;
1745a8599bd8SSage Weil 		}
1746a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
1747a8599bd8SSage Weil 	return ret;
1748a8599bd8SSage Weil }
1749a8599bd8SSage Weil 
1750a8599bd8SSage Weil /*
1751a8599bd8SSage Weil  * Wait on any unsafe replies for the given inode.  First wait on the
1752a8599bd8SSage Weil  * newest request, and make that the upper bound.  Then, if there are
1753a8599bd8SSage Weil  * more requests, keep waiting on the oldest as long as it is still older
1754a8599bd8SSage Weil  * than the original request.
1755a8599bd8SSage Weil  */
1756a8599bd8SSage Weil static void sync_write_wait(struct inode *inode)
1757a8599bd8SSage Weil {
1758a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
1759a8599bd8SSage Weil 	struct list_head *head = &ci->i_unsafe_writes;
1760a8599bd8SSage Weil 	struct ceph_osd_request *req;
1761a8599bd8SSage Weil 	u64 last_tid;
1762a8599bd8SSage Weil 
1763a8599bd8SSage Weil 	spin_lock(&ci->i_unsafe_lock);
1764a8599bd8SSage Weil 	if (list_empty(head))
1765a8599bd8SSage Weil 		goto out;
1766a8599bd8SSage Weil 
1767a8599bd8SSage Weil 	/* set upper bound as _last_ entry in chain */
1768a8599bd8SSage Weil 	req = list_entry(head->prev, struct ceph_osd_request,
1769a8599bd8SSage Weil 			 r_unsafe_item);
1770a8599bd8SSage Weil 	last_tid = req->r_tid;
1771a8599bd8SSage Weil 
1772a8599bd8SSage Weil 	do {
1773a8599bd8SSage Weil 		ceph_osdc_get_request(req);
1774a8599bd8SSage Weil 		spin_unlock(&ci->i_unsafe_lock);
1775a8599bd8SSage Weil 		dout("sync_write_wait on tid %llu (until %llu)\n",
1776a8599bd8SSage Weil 		     req->r_tid, last_tid);
1777a8599bd8SSage Weil 		wait_for_completion(&req->r_safe_completion);
1778a8599bd8SSage Weil 		spin_lock(&ci->i_unsafe_lock);
1779a8599bd8SSage Weil 		ceph_osdc_put_request(req);
1780a8599bd8SSage Weil 
1781a8599bd8SSage Weil 		/*
1782a8599bd8SSage Weil 		 * from here on look at first entry in chain, since we
1783a8599bd8SSage Weil 		 * only want to wait for anything older than last_tid
1784a8599bd8SSage Weil 		 */
1785a8599bd8SSage Weil 		if (list_empty(head))
1786a8599bd8SSage Weil 			break;
1787a8599bd8SSage Weil 		req = list_entry(head->next, struct ceph_osd_request,
1788a8599bd8SSage Weil 				 r_unsafe_item);
1789a8599bd8SSage Weil 	} while (req->r_tid < last_tid);
1790a8599bd8SSage Weil out:
1791a8599bd8SSage Weil 	spin_unlock(&ci->i_unsafe_lock);
1792a8599bd8SSage Weil }
1793a8599bd8SSage Weil 
17947ea80859SChristoph Hellwig int ceph_fsync(struct file *file, int datasync)
1795a8599bd8SSage Weil {
17967ea80859SChristoph Hellwig 	struct inode *inode = file->f_mapping->host;
1797a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
1798a8599bd8SSage Weil 	unsigned flush_tid;
1799a8599bd8SSage Weil 	int ret;
1800a8599bd8SSage Weil 	int dirty;
1801a8599bd8SSage Weil 
1802a8599bd8SSage Weil 	dout("fsync %p%s\n", inode, datasync ? " datasync" : "");
1803a8599bd8SSage Weil 	sync_write_wait(inode);
1804a8599bd8SSage Weil 
1805a8599bd8SSage Weil 	ret = filemap_write_and_wait(inode->i_mapping);
1806a8599bd8SSage Weil 	if (ret < 0)
1807a8599bd8SSage Weil 		return ret;
1808a8599bd8SSage Weil 
1809a8599bd8SSage Weil 	dirty = try_flush_caps(inode, NULL, &flush_tid);
1810a8599bd8SSage Weil 	dout("fsync dirty caps are %s\n", ceph_cap_string(dirty));
1811a8599bd8SSage Weil 
1812a8599bd8SSage Weil 	/*
1813a8599bd8SSage Weil 	 * only wait on non-file metadata writeback (the mds
1814a8599bd8SSage Weil 	 * can recover size and mtime, so we don't need to
1815a8599bd8SSage Weil 	 * wait for that)
1816a8599bd8SSage Weil 	 */
1817a8599bd8SSage Weil 	if (!datasync && (dirty & ~CEPH_CAP_ANY_FILE_WR)) {
1818a8599bd8SSage Weil 		dout("fsync waiting for flush_tid %u\n", flush_tid);
1819a8599bd8SSage Weil 		ret = wait_event_interruptible(ci->i_cap_wq,
1820a8599bd8SSage Weil 				       caps_are_flushed(inode, flush_tid));
1821a8599bd8SSage Weil 	}
1822a8599bd8SSage Weil 
1823a8599bd8SSage Weil 	dout("fsync %p%s done\n", inode, datasync ? " datasync" : "");
1824a8599bd8SSage Weil 	return ret;
1825a8599bd8SSage Weil }
1826a8599bd8SSage Weil 
1827a8599bd8SSage Weil /*
1828a8599bd8SSage Weil  * Flush any dirty caps back to the mds.  If we aren't asked to wait,
1829a8599bd8SSage Weil  * queue inode for flush but don't do so immediately, because we can
1830a8599bd8SSage Weil  * get by with fewer MDS messages if we wait for data writeback to
1831a8599bd8SSage Weil  * complete first.
1832a8599bd8SSage Weil  */
1833f1a3d572SStephen Rothwell int ceph_write_inode(struct inode *inode, struct writeback_control *wbc)
1834a8599bd8SSage Weil {
1835a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
1836a8599bd8SSage Weil 	unsigned flush_tid;
1837a8599bd8SSage Weil 	int err = 0;
1838a8599bd8SSage Weil 	int dirty;
1839f1a3d572SStephen Rothwell 	int wait = wbc->sync_mode == WB_SYNC_ALL;
1840a8599bd8SSage Weil 
1841a8599bd8SSage Weil 	dout("write_inode %p wait=%d\n", inode, wait);
1842a8599bd8SSage Weil 	if (wait) {
1843a8599bd8SSage Weil 		dirty = try_flush_caps(inode, NULL, &flush_tid);
1844a8599bd8SSage Weil 		if (dirty)
1845a8599bd8SSage Weil 			err = wait_event_interruptible(ci->i_cap_wq,
1846a8599bd8SSage Weil 				       caps_are_flushed(inode, flush_tid));
1847a8599bd8SSage Weil 	} else {
1848640ef79dSCheng Renquan 		struct ceph_mds_client *mdsc =
1849640ef79dSCheng Renquan 			&ceph_sb_to_client(inode->i_sb)->mdsc;
1850a8599bd8SSage Weil 
1851a8599bd8SSage Weil 		spin_lock(&inode->i_lock);
1852a8599bd8SSage Weil 		if (__ceph_caps_dirty(ci))
1853a8599bd8SSage Weil 			__cap_delay_requeue_front(mdsc, ci);
1854a8599bd8SSage Weil 		spin_unlock(&inode->i_lock);
1855a8599bd8SSage Weil 	}
1856a8599bd8SSage Weil 	return err;
1857a8599bd8SSage Weil }
1858a8599bd8SSage Weil 
1859a8599bd8SSage Weil /*
1860a8599bd8SSage Weil  * After a recovering MDS goes active, we need to resend any caps
1861a8599bd8SSage Weil  * we were flushing.
1862a8599bd8SSage Weil  *
1863a8599bd8SSage Weil  * Caller holds session->s_mutex.
1864a8599bd8SSage Weil  */
1865a8599bd8SSage Weil static void kick_flushing_capsnaps(struct ceph_mds_client *mdsc,
1866a8599bd8SSage Weil 				   struct ceph_mds_session *session)
1867a8599bd8SSage Weil {
1868a8599bd8SSage Weil 	struct ceph_cap_snap *capsnap;
1869a8599bd8SSage Weil 
1870a8599bd8SSage Weil 	dout("kick_flushing_capsnaps mds%d\n", session->s_mds);
1871a8599bd8SSage Weil 	list_for_each_entry(capsnap, &session->s_cap_snaps_flushing,
1872a8599bd8SSage Weil 			    flushing_item) {
1873a8599bd8SSage Weil 		struct ceph_inode_info *ci = capsnap->ci;
1874a8599bd8SSage Weil 		struct inode *inode = &ci->vfs_inode;
1875a8599bd8SSage Weil 		struct ceph_cap *cap;
1876a8599bd8SSage Weil 
1877a8599bd8SSage Weil 		spin_lock(&inode->i_lock);
1878a8599bd8SSage Weil 		cap = ci->i_auth_cap;
1879a8599bd8SSage Weil 		if (cap && cap->session == session) {
1880a8599bd8SSage Weil 			dout("kick_flushing_caps %p cap %p capsnap %p\n", inode,
1881a8599bd8SSage Weil 			     cap, capsnap);
1882a8599bd8SSage Weil 			__ceph_flush_snaps(ci, &session);
1883a8599bd8SSage Weil 		} else {
1884a8599bd8SSage Weil 			pr_err("%p auth cap %p not mds%d ???\n", inode,
1885a8599bd8SSage Weil 			       cap, session->s_mds);
1886a8599bd8SSage Weil 		}
18870b0c06d1SSage Weil 		spin_unlock(&inode->i_lock);
1888a8599bd8SSage Weil 	}
1889a8599bd8SSage Weil }
1890a8599bd8SSage Weil 
1891a8599bd8SSage Weil void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
1892a8599bd8SSage Weil 			     struct ceph_mds_session *session)
1893a8599bd8SSage Weil {
1894a8599bd8SSage Weil 	struct ceph_inode_info *ci;
1895a8599bd8SSage Weil 
1896a8599bd8SSage Weil 	kick_flushing_capsnaps(mdsc, session);
1897a8599bd8SSage Weil 
1898a8599bd8SSage Weil 	dout("kick_flushing_caps mds%d\n", session->s_mds);
1899a8599bd8SSage Weil 	list_for_each_entry(ci, &session->s_cap_flushing, i_flushing_item) {
1900a8599bd8SSage Weil 		struct inode *inode = &ci->vfs_inode;
1901a8599bd8SSage Weil 		struct ceph_cap *cap;
1902a8599bd8SSage Weil 		int delayed = 0;
1903a8599bd8SSage Weil 
1904a8599bd8SSage Weil 		spin_lock(&inode->i_lock);
1905a8599bd8SSage Weil 		cap = ci->i_auth_cap;
1906a8599bd8SSage Weil 		if (cap && cap->session == session) {
1907a8599bd8SSage Weil 			dout("kick_flushing_caps %p cap %p %s\n", inode,
1908a8599bd8SSage Weil 			     cap, ceph_cap_string(ci->i_flushing_caps));
1909a8599bd8SSage Weil 			delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
1910a8599bd8SSage Weil 					     __ceph_caps_used(ci),
1911a8599bd8SSage Weil 					     __ceph_caps_wanted(ci),
1912a8599bd8SSage Weil 					     cap->issued | cap->implemented,
1913a8599bd8SSage Weil 					     ci->i_flushing_caps, NULL);
1914a8599bd8SSage Weil 			if (delayed) {
1915a8599bd8SSage Weil 				spin_lock(&inode->i_lock);
1916a8599bd8SSage Weil 				__cap_delay_requeue(mdsc, ci);
1917a8599bd8SSage Weil 				spin_unlock(&inode->i_lock);
1918a8599bd8SSage Weil 			}
1919a8599bd8SSage Weil 		} else {
1920a8599bd8SSage Weil 			pr_err("%p auth cap %p not mds%d ???\n", inode,
1921a8599bd8SSage Weil 			       cap, session->s_mds);
1922a8599bd8SSage Weil 			spin_unlock(&inode->i_lock);
1923a8599bd8SSage Weil 		}
1924a8599bd8SSage Weil 	}
1925a8599bd8SSage Weil }
1926a8599bd8SSage Weil 
1927a8599bd8SSage Weil 
1928a8599bd8SSage Weil /*
1929a8599bd8SSage Weil  * Take references to capabilities we hold, so that we don't release
1930a8599bd8SSage Weil  * them to the MDS prematurely.
1931a8599bd8SSage Weil  *
1932a8599bd8SSage Weil  * Protected by i_lock.
1933a8599bd8SSage Weil  */
1934a8599bd8SSage Weil static void __take_cap_refs(struct ceph_inode_info *ci, int got)
1935a8599bd8SSage Weil {
1936a8599bd8SSage Weil 	if (got & CEPH_CAP_PIN)
1937a8599bd8SSage Weil 		ci->i_pin_ref++;
1938a8599bd8SSage Weil 	if (got & CEPH_CAP_FILE_RD)
1939a8599bd8SSage Weil 		ci->i_rd_ref++;
1940a8599bd8SSage Weil 	if (got & CEPH_CAP_FILE_CACHE)
1941a8599bd8SSage Weil 		ci->i_rdcache_ref++;
1942a8599bd8SSage Weil 	if (got & CEPH_CAP_FILE_WR)
1943a8599bd8SSage Weil 		ci->i_wr_ref++;
1944a8599bd8SSage Weil 	if (got & CEPH_CAP_FILE_BUFFER) {
1945a8599bd8SSage Weil 		if (ci->i_wrbuffer_ref == 0)
1946a8599bd8SSage Weil 			igrab(&ci->vfs_inode);
1947a8599bd8SSage Weil 		ci->i_wrbuffer_ref++;
1948a8599bd8SSage Weil 		dout("__take_cap_refs %p wrbuffer %d -> %d (?)\n",
1949a8599bd8SSage Weil 		     &ci->vfs_inode, ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref);
1950a8599bd8SSage Weil 	}
1951a8599bd8SSage Weil }
1952a8599bd8SSage Weil 
1953a8599bd8SSage Weil /*
1954a8599bd8SSage Weil  * Try to grab cap references.  Specify those refs we @want, and the
1955a8599bd8SSage Weil  * minimal set we @need.  Also include the larger offset we are writing
1956a8599bd8SSage Weil  * to (when applicable), and check against max_size here as well.
1957a8599bd8SSage Weil  * Note that caller is responsible for ensuring max_size increases are
1958a8599bd8SSage Weil  * requested from the MDS.
1959a8599bd8SSage Weil  */
1960a8599bd8SSage Weil static int try_get_cap_refs(struct ceph_inode_info *ci, int need, int want,
1961a8599bd8SSage Weil 			    int *got, loff_t endoff, int *check_max, int *err)
1962a8599bd8SSage Weil {
1963a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
1964a8599bd8SSage Weil 	int ret = 0;
1965a8599bd8SSage Weil 	int have, implemented;
1966195d3ce2SSage Weil 	int file_wanted;
1967a8599bd8SSage Weil 
1968a8599bd8SSage Weil 	dout("get_cap_refs %p need %s want %s\n", inode,
1969a8599bd8SSage Weil 	     ceph_cap_string(need), ceph_cap_string(want));
1970a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
1971a8599bd8SSage Weil 
1972195d3ce2SSage Weil 	/* make sure file is actually open */
1973195d3ce2SSage Weil 	file_wanted = __ceph_caps_file_wanted(ci);
1974195d3ce2SSage Weil 	if ((file_wanted & need) == 0) {
1975195d3ce2SSage Weil 		dout("try_get_cap_refs need %s file_wanted %s, EBADF\n",
1976195d3ce2SSage Weil 		     ceph_cap_string(need), ceph_cap_string(file_wanted));
1977a8599bd8SSage Weil 		*err = -EBADF;
1978a8599bd8SSage Weil 		ret = 1;
1979a8599bd8SSage Weil 		goto out;
1980a8599bd8SSage Weil 	}
1981a8599bd8SSage Weil 
1982a8599bd8SSage Weil 	if (need & CEPH_CAP_FILE_WR) {
1983a8599bd8SSage Weil 		if (endoff >= 0 && endoff > (loff_t)ci->i_max_size) {
1984a8599bd8SSage Weil 			dout("get_cap_refs %p endoff %llu > maxsize %llu\n",
1985a8599bd8SSage Weil 			     inode, endoff, ci->i_max_size);
1986a8599bd8SSage Weil 			if (endoff > ci->i_wanted_max_size) {
1987a8599bd8SSage Weil 				*check_max = 1;
1988a8599bd8SSage Weil 				ret = 1;
1989a8599bd8SSage Weil 			}
1990a8599bd8SSage Weil 			goto out;
1991a8599bd8SSage Weil 		}
1992a8599bd8SSage Weil 		/*
1993a8599bd8SSage Weil 		 * If a sync write is in progress, we must wait, so that we
1994a8599bd8SSage Weil 		 * can get a final snapshot value for size+mtime.
1995a8599bd8SSage Weil 		 */
1996a8599bd8SSage Weil 		if (__ceph_have_pending_cap_snap(ci)) {
1997a8599bd8SSage Weil 			dout("get_cap_refs %p cap_snap_pending\n", inode);
1998a8599bd8SSage Weil 			goto out;
1999a8599bd8SSage Weil 		}
2000a8599bd8SSage Weil 	}
2001a8599bd8SSage Weil 	have = __ceph_caps_issued(ci, &implemented);
2002a8599bd8SSage Weil 
2003a8599bd8SSage Weil 	/*
2004a8599bd8SSage Weil 	 * disallow writes while a truncate is pending
2005a8599bd8SSage Weil 	 */
2006a8599bd8SSage Weil 	if (ci->i_truncate_pending)
2007a8599bd8SSage Weil 		have &= ~CEPH_CAP_FILE_WR;
2008a8599bd8SSage Weil 
2009a8599bd8SSage Weil 	if ((have & need) == need) {
2010a8599bd8SSage Weil 		/*
2011a8599bd8SSage Weil 		 * Look at (implemented & ~have & not) so that we keep waiting
2012a8599bd8SSage Weil 		 * on transition from wanted -> needed caps.  This is needed
2013a8599bd8SSage Weil 		 * for WRBUFFER|WR -> WR to avoid a new WR sync write from
2014a8599bd8SSage Weil 		 * going before a prior buffered writeback happens.
2015a8599bd8SSage Weil 		 */
2016a8599bd8SSage Weil 		int not = want & ~(have & need);
2017a8599bd8SSage Weil 		int revoking = implemented & ~have;
2018a8599bd8SSage Weil 		dout("get_cap_refs %p have %s but not %s (revoking %s)\n",
2019a8599bd8SSage Weil 		     inode, ceph_cap_string(have), ceph_cap_string(not),
2020a8599bd8SSage Weil 		     ceph_cap_string(revoking));
2021a8599bd8SSage Weil 		if ((revoking & not) == 0) {
2022a8599bd8SSage Weil 			*got = need | (have & want);
2023a8599bd8SSage Weil 			__take_cap_refs(ci, *got);
2024a8599bd8SSage Weil 			ret = 1;
2025a8599bd8SSage Weil 		}
2026a8599bd8SSage Weil 	} else {
2027a8599bd8SSage Weil 		dout("get_cap_refs %p have %s needed %s\n", inode,
2028a8599bd8SSage Weil 		     ceph_cap_string(have), ceph_cap_string(need));
2029a8599bd8SSage Weil 	}
2030a8599bd8SSage Weil out:
2031a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2032a8599bd8SSage Weil 	dout("get_cap_refs %p ret %d got %s\n", inode,
2033a8599bd8SSage Weil 	     ret, ceph_cap_string(*got));
2034a8599bd8SSage Weil 	return ret;
2035a8599bd8SSage Weil }
2036a8599bd8SSage Weil 
2037a8599bd8SSage Weil /*
2038a8599bd8SSage Weil  * Check the offset we are writing up to against our current
2039a8599bd8SSage Weil  * max_size.  If necessary, tell the MDS we want to write to
2040a8599bd8SSage Weil  * a larger offset.
2041a8599bd8SSage Weil  */
2042a8599bd8SSage Weil static void check_max_size(struct inode *inode, loff_t endoff)
2043a8599bd8SSage Weil {
2044a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2045a8599bd8SSage Weil 	int check = 0;
2046a8599bd8SSage Weil 
2047a8599bd8SSage Weil 	/* do we need to explicitly request a larger max_size? */
2048a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2049a8599bd8SSage Weil 	if ((endoff >= ci->i_max_size ||
2050a8599bd8SSage Weil 	     endoff > (inode->i_size << 1)) &&
2051a8599bd8SSage Weil 	    endoff > ci->i_wanted_max_size) {
2052a8599bd8SSage Weil 		dout("write %p at large endoff %llu, req max_size\n",
2053a8599bd8SSage Weil 		     inode, endoff);
2054a8599bd8SSage Weil 		ci->i_wanted_max_size = endoff;
2055a8599bd8SSage Weil 		check = 1;
2056a8599bd8SSage Weil 	}
2057a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2058a8599bd8SSage Weil 	if (check)
2059a8599bd8SSage Weil 		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
2060a8599bd8SSage Weil }
2061a8599bd8SSage Weil 
2062a8599bd8SSage Weil /*
2063a8599bd8SSage Weil  * Wait for caps, and take cap references.  If we can't get a WR cap
2064a8599bd8SSage Weil  * due to a small max_size, make sure we check_max_size (and possibly
2065a8599bd8SSage Weil  * ask the mds) so we don't get hung up indefinitely.
2066a8599bd8SSage Weil  */
2067a8599bd8SSage Weil int ceph_get_caps(struct ceph_inode_info *ci, int need, int want, int *got,
2068a8599bd8SSage Weil 		  loff_t endoff)
2069a8599bd8SSage Weil {
2070a8599bd8SSage Weil 	int check_max, ret, err;
2071a8599bd8SSage Weil 
2072a8599bd8SSage Weil retry:
2073a8599bd8SSage Weil 	if (endoff > 0)
2074a8599bd8SSage Weil 		check_max_size(&ci->vfs_inode, endoff);
2075a8599bd8SSage Weil 	check_max = 0;
2076a8599bd8SSage Weil 	err = 0;
2077a8599bd8SSage Weil 	ret = wait_event_interruptible(ci->i_cap_wq,
2078a8599bd8SSage Weil 				       try_get_cap_refs(ci, need, want,
2079a8599bd8SSage Weil 							got, endoff,
2080a8599bd8SSage Weil 							&check_max, &err));
2081a8599bd8SSage Weil 	if (err)
2082a8599bd8SSage Weil 		ret = err;
2083a8599bd8SSage Weil 	if (check_max)
2084a8599bd8SSage Weil 		goto retry;
2085a8599bd8SSage Weil 	return ret;
2086a8599bd8SSage Weil }
2087a8599bd8SSage Weil 
2088a8599bd8SSage Weil /*
2089a8599bd8SSage Weil  * Take cap refs.  Caller must already know we hold at least one ref
2090a8599bd8SSage Weil  * on the caps in question or we don't know this is safe.
2091a8599bd8SSage Weil  */
2092a8599bd8SSage Weil void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps)
2093a8599bd8SSage Weil {
2094a8599bd8SSage Weil 	spin_lock(&ci->vfs_inode.i_lock);
2095a8599bd8SSage Weil 	__take_cap_refs(ci, caps);
2096a8599bd8SSage Weil 	spin_unlock(&ci->vfs_inode.i_lock);
2097a8599bd8SSage Weil }
2098a8599bd8SSage Weil 
2099a8599bd8SSage Weil /*
2100a8599bd8SSage Weil  * Release cap refs.
2101a8599bd8SSage Weil  *
2102a8599bd8SSage Weil  * If we released the last ref on any given cap, call ceph_check_caps
2103a8599bd8SSage Weil  * to release (or schedule a release).
2104a8599bd8SSage Weil  *
2105a8599bd8SSage Weil  * If we are releasing a WR cap (from a sync write), finalize any affected
2106a8599bd8SSage Weil  * cap_snap, and wake up any waiters.
2107a8599bd8SSage Weil  */
2108a8599bd8SSage Weil void ceph_put_cap_refs(struct ceph_inode_info *ci, int had)
2109a8599bd8SSage Weil {
2110a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
2111a8599bd8SSage Weil 	int last = 0, put = 0, flushsnaps = 0, wake = 0;
2112a8599bd8SSage Weil 	struct ceph_cap_snap *capsnap;
2113a8599bd8SSage Weil 
2114a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2115a8599bd8SSage Weil 	if (had & CEPH_CAP_PIN)
2116a8599bd8SSage Weil 		--ci->i_pin_ref;
2117a8599bd8SSage Weil 	if (had & CEPH_CAP_FILE_RD)
2118a8599bd8SSage Weil 		if (--ci->i_rd_ref == 0)
2119a8599bd8SSage Weil 			last++;
2120a8599bd8SSage Weil 	if (had & CEPH_CAP_FILE_CACHE)
2121a8599bd8SSage Weil 		if (--ci->i_rdcache_ref == 0)
2122a8599bd8SSage Weil 			last++;
2123a8599bd8SSage Weil 	if (had & CEPH_CAP_FILE_BUFFER) {
2124a8599bd8SSage Weil 		if (--ci->i_wrbuffer_ref == 0) {
2125a8599bd8SSage Weil 			last++;
2126a8599bd8SSage Weil 			put++;
2127a8599bd8SSage Weil 		}
2128a8599bd8SSage Weil 		dout("put_cap_refs %p wrbuffer %d -> %d (?)\n",
2129a8599bd8SSage Weil 		     inode, ci->i_wrbuffer_ref+1, ci->i_wrbuffer_ref);
2130a8599bd8SSage Weil 	}
2131a8599bd8SSage Weil 	if (had & CEPH_CAP_FILE_WR)
2132a8599bd8SSage Weil 		if (--ci->i_wr_ref == 0) {
2133a8599bd8SSage Weil 			last++;
2134a8599bd8SSage Weil 			if (!list_empty(&ci->i_cap_snaps)) {
2135a8599bd8SSage Weil 				capsnap = list_first_entry(&ci->i_cap_snaps,
2136a8599bd8SSage Weil 						     struct ceph_cap_snap,
2137a8599bd8SSage Weil 						     ci_item);
2138a8599bd8SSage Weil 				if (capsnap->writing) {
2139a8599bd8SSage Weil 					capsnap->writing = 0;
2140a8599bd8SSage Weil 					flushsnaps =
2141a8599bd8SSage Weil 						__ceph_finish_cap_snap(ci,
2142a8599bd8SSage Weil 								       capsnap);
2143a8599bd8SSage Weil 					wake = 1;
2144a8599bd8SSage Weil 				}
2145a8599bd8SSage Weil 			}
2146a8599bd8SSage Weil 		}
2147a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2148a8599bd8SSage Weil 
2149819ccbfaSSage Weil 	dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had),
2150819ccbfaSSage Weil 	     last ? " last" : "", put ? " put" : "");
2151a8599bd8SSage Weil 
2152a8599bd8SSage Weil 	if (last && !flushsnaps)
2153a8599bd8SSage Weil 		ceph_check_caps(ci, 0, NULL);
2154a8599bd8SSage Weil 	else if (flushsnaps)
2155a8599bd8SSage Weil 		ceph_flush_snaps(ci);
2156a8599bd8SSage Weil 	if (wake)
215703066f23SYehuda Sadeh 		wake_up_all(&ci->i_cap_wq);
2158a8599bd8SSage Weil 	if (put)
2159a8599bd8SSage Weil 		iput(inode);
2160a8599bd8SSage Weil }
2161a8599bd8SSage Weil 
2162a8599bd8SSage Weil /*
2163a8599bd8SSage Weil  * Release @nr WRBUFFER refs on dirty pages for the given @snapc snap
2164a8599bd8SSage Weil  * context.  Adjust per-snap dirty page accounting as appropriate.
2165a8599bd8SSage Weil  * Once all dirty data for a cap_snap is flushed, flush snapped file
2166a8599bd8SSage Weil  * metadata back to the MDS.  If we dropped the last ref, call
2167a8599bd8SSage Weil  * ceph_check_caps.
2168a8599bd8SSage Weil  */
2169a8599bd8SSage Weil void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
2170a8599bd8SSage Weil 				struct ceph_snap_context *snapc)
2171a8599bd8SSage Weil {
2172a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
2173a8599bd8SSage Weil 	int last = 0;
2174819ccbfaSSage Weil 	int complete_capsnap = 0;
2175819ccbfaSSage Weil 	int drop_capsnap = 0;
2176a8599bd8SSage Weil 	int found = 0;
2177a8599bd8SSage Weil 	struct ceph_cap_snap *capsnap = NULL;
2178a8599bd8SSage Weil 
2179a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2180a8599bd8SSage Weil 	ci->i_wrbuffer_ref -= nr;
2181a8599bd8SSage Weil 	last = !ci->i_wrbuffer_ref;
2182a8599bd8SSage Weil 
2183a8599bd8SSage Weil 	if (ci->i_head_snapc == snapc) {
2184a8599bd8SSage Weil 		ci->i_wrbuffer_ref_head -= nr;
2185a8599bd8SSage Weil 		if (!ci->i_wrbuffer_ref_head) {
2186a8599bd8SSage Weil 			ceph_put_snap_context(ci->i_head_snapc);
2187a8599bd8SSage Weil 			ci->i_head_snapc = NULL;
2188a8599bd8SSage Weil 		}
2189a8599bd8SSage Weil 		dout("put_wrbuffer_cap_refs on %p head %d/%d -> %d/%d %s\n",
2190a8599bd8SSage Weil 		     inode,
2191a8599bd8SSage Weil 		     ci->i_wrbuffer_ref+nr, ci->i_wrbuffer_ref_head+nr,
2192a8599bd8SSage Weil 		     ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
2193a8599bd8SSage Weil 		     last ? " LAST" : "");
2194a8599bd8SSage Weil 	} else {
2195a8599bd8SSage Weil 		list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
2196a8599bd8SSage Weil 			if (capsnap->context == snapc) {
2197a8599bd8SSage Weil 				found = 1;
2198a8599bd8SSage Weil 				break;
2199a8599bd8SSage Weil 			}
2200a8599bd8SSage Weil 		}
2201a8599bd8SSage Weil 		BUG_ON(!found);
2202819ccbfaSSage Weil 		capsnap->dirty_pages -= nr;
2203819ccbfaSSage Weil 		if (capsnap->dirty_pages == 0) {
2204819ccbfaSSage Weil 			complete_capsnap = 1;
2205819ccbfaSSage Weil 			if (capsnap->dirty == 0)
2206819ccbfaSSage Weil 				/* cap writeback completed before we created
2207819ccbfaSSage Weil 				 * the cap_snap; no FLUSHSNAP is needed */
2208819ccbfaSSage Weil 				drop_capsnap = 1;
2209819ccbfaSSage Weil 		}
2210a8599bd8SSage Weil 		dout("put_wrbuffer_cap_refs on %p cap_snap %p "
2211819ccbfaSSage Weil 		     " snap %lld %d/%d -> %d/%d %s%s%s\n",
2212a8599bd8SSage Weil 		     inode, capsnap, capsnap->context->seq,
2213a8599bd8SSage Weil 		     ci->i_wrbuffer_ref+nr, capsnap->dirty_pages + nr,
2214a8599bd8SSage Weil 		     ci->i_wrbuffer_ref, capsnap->dirty_pages,
2215a8599bd8SSage Weil 		     last ? " (wrbuffer last)" : "",
2216819ccbfaSSage Weil 		     complete_capsnap ? " (complete capsnap)" : "",
2217819ccbfaSSage Weil 		     drop_capsnap ? " (drop capsnap)" : "");
2218819ccbfaSSage Weil 		if (drop_capsnap) {
2219819ccbfaSSage Weil 			ceph_put_snap_context(capsnap->context);
2220819ccbfaSSage Weil 			list_del(&capsnap->ci_item);
2221819ccbfaSSage Weil 			list_del(&capsnap->flushing_item);
2222819ccbfaSSage Weil 			ceph_put_cap_snap(capsnap);
2223819ccbfaSSage Weil 		}
2224a8599bd8SSage Weil 	}
2225a8599bd8SSage Weil 
2226a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2227a8599bd8SSage Weil 
2228a8599bd8SSage Weil 	if (last) {
2229a8599bd8SSage Weil 		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
2230a8599bd8SSage Weil 		iput(inode);
2231819ccbfaSSage Weil 	} else if (complete_capsnap) {
2232a8599bd8SSage Weil 		ceph_flush_snaps(ci);
223303066f23SYehuda Sadeh 		wake_up_all(&ci->i_cap_wq);
2234a8599bd8SSage Weil 	}
2235819ccbfaSSage Weil 	if (drop_capsnap)
2236819ccbfaSSage Weil 		iput(inode);
2237a8599bd8SSage Weil }
2238a8599bd8SSage Weil 
2239a8599bd8SSage Weil /*
2240a8599bd8SSage Weil  * Handle a cap GRANT message from the MDS.  (Note that a GRANT may
2241a8599bd8SSage Weil  * actually be a revocation if it specifies a smaller cap set.)
2242a8599bd8SSage Weil  *
224315637c8bSSage Weil  * caller holds s_mutex and i_lock, we drop both.
224415637c8bSSage Weil  *
2245a8599bd8SSage Weil  * return value:
2246a8599bd8SSage Weil  *  0 - ok
2247a8599bd8SSage Weil  *  1 - check_caps on auth cap only (writeback)
2248a8599bd8SSage Weil  *  2 - check_caps (ack revoke)
2249a8599bd8SSage Weil  */
225015637c8bSSage Weil static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
2251a8599bd8SSage Weil 			     struct ceph_mds_session *session,
2252a8599bd8SSage Weil 			     struct ceph_cap *cap,
2253a8599bd8SSage Weil 			     struct ceph_buffer *xattr_buf)
2254a8599bd8SSage Weil 	__releases(inode->i_lock)
225515637c8bSSage Weil 	__releases(session->s_mutex)
2256a8599bd8SSage Weil {
2257a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2258a8599bd8SSage Weil 	int mds = session->s_mds;
2259a8599bd8SSage Weil 	int seq = le32_to_cpu(grant->seq);
2260a8599bd8SSage Weil 	int newcaps = le32_to_cpu(grant->caps);
2261a8599bd8SSage Weil 	int issued, implemented, used, wanted, dirty;
2262a8599bd8SSage Weil 	u64 size = le64_to_cpu(grant->size);
2263a8599bd8SSage Weil 	u64 max_size = le64_to_cpu(grant->max_size);
2264a8599bd8SSage Weil 	struct timespec mtime, atime, ctime;
226515637c8bSSage Weil 	int check_caps = 0;
2266a8599bd8SSage Weil 	int wake = 0;
2267a8599bd8SSage Weil 	int writeback = 0;
2268a8599bd8SSage Weil 	int revoked_rdcache = 0;
22693c6f6b79SSage Weil 	int queue_invalidate = 0;
2270a8599bd8SSage Weil 
2271a8599bd8SSage Weil 	dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
2272a8599bd8SSage Weil 	     inode, cap, mds, seq, ceph_cap_string(newcaps));
2273a8599bd8SSage Weil 	dout(" size %llu max_size %llu, i_size %llu\n", size, max_size,
2274a8599bd8SSage Weil 		inode->i_size);
2275a8599bd8SSage Weil 
2276a8599bd8SSage Weil 	/*
2277a8599bd8SSage Weil 	 * If CACHE is being revoked, and we have no dirty buffers,
2278a8599bd8SSage Weil 	 * try to invalidate (once).  (If there are dirty buffers, we
2279a8599bd8SSage Weil 	 * will invalidate _after_ writeback.)
2280a8599bd8SSage Weil 	 */
22812962507cSSage Weil 	if (((cap->issued & ~newcaps) & (CEPH_CAP_FILE_CACHE|
22822962507cSSage Weil 					 CEPH_CAP_FILE_LAZYIO)) &&
2283bcd2cbd1SYehuda Sadeh 	    !ci->i_wrbuffer_ref) {
22845ecad6fdSSage Weil 		if (try_nonblocking_invalidate(inode) == 0) {
22855ecad6fdSSage Weil 			revoked_rdcache = 1;
22865ecad6fdSSage Weil 		} else {
2287a8599bd8SSage Weil 			/* there were locked pages.. invalidate later
2288a8599bd8SSage Weil 			   in a separate thread. */
2289a8599bd8SSage Weil 			if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
22903c6f6b79SSage Weil 				queue_invalidate = 1;
2291a8599bd8SSage Weil 				ci->i_rdcache_revoking = ci->i_rdcache_gen;
2292a8599bd8SSage Weil 			}
2293a8599bd8SSage Weil 		}
2294a8599bd8SSage Weil 	}
2295a8599bd8SSage Weil 
2296a8599bd8SSage Weil 	/* side effects now are allowed */
2297a8599bd8SSage Weil 
2298a8599bd8SSage Weil 	issued = __ceph_caps_issued(ci, &implemented);
2299a8599bd8SSage Weil 	issued |= implemented | __ceph_caps_dirty(ci);
2300a8599bd8SSage Weil 
2301685f9a5dSSage Weil 	cap->cap_gen = session->s_cap_gen;
2302a8599bd8SSage Weil 
2303a8599bd8SSage Weil 	__check_cap_issue(ci, cap, newcaps);
2304a8599bd8SSage Weil 
2305a8599bd8SSage Weil 	if ((issued & CEPH_CAP_AUTH_EXCL) == 0) {
2306a8599bd8SSage Weil 		inode->i_mode = le32_to_cpu(grant->mode);
2307a8599bd8SSage Weil 		inode->i_uid = le32_to_cpu(grant->uid);
2308a8599bd8SSage Weil 		inode->i_gid = le32_to_cpu(grant->gid);
2309a8599bd8SSage Weil 		dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode,
2310a8599bd8SSage Weil 		     inode->i_uid, inode->i_gid);
2311a8599bd8SSage Weil 	}
2312a8599bd8SSage Weil 
2313a8599bd8SSage Weil 	if ((issued & CEPH_CAP_LINK_EXCL) == 0)
2314a8599bd8SSage Weil 		inode->i_nlink = le32_to_cpu(grant->nlink);
2315a8599bd8SSage Weil 
2316a8599bd8SSage Weil 	if ((issued & CEPH_CAP_XATTR_EXCL) == 0 && grant->xattr_len) {
2317a8599bd8SSage Weil 		int len = le32_to_cpu(grant->xattr_len);
2318a8599bd8SSage Weil 		u64 version = le64_to_cpu(grant->xattr_version);
2319a8599bd8SSage Weil 
2320a8599bd8SSage Weil 		if (version > ci->i_xattrs.version) {
2321a8599bd8SSage Weil 			dout(" got new xattrs v%llu on %p len %d\n",
2322a8599bd8SSage Weil 			     version, inode, len);
2323a8599bd8SSage Weil 			if (ci->i_xattrs.blob)
2324a8599bd8SSage Weil 				ceph_buffer_put(ci->i_xattrs.blob);
2325a8599bd8SSage Weil 			ci->i_xattrs.blob = ceph_buffer_get(xattr_buf);
2326a8599bd8SSage Weil 			ci->i_xattrs.version = version;
2327a8599bd8SSage Weil 		}
2328a8599bd8SSage Weil 	}
2329a8599bd8SSage Weil 
2330a8599bd8SSage Weil 	/* size/ctime/mtime/atime? */
2331a8599bd8SSage Weil 	ceph_fill_file_size(inode, issued,
2332a8599bd8SSage Weil 			    le32_to_cpu(grant->truncate_seq),
2333a8599bd8SSage Weil 			    le64_to_cpu(grant->truncate_size), size);
2334a8599bd8SSage Weil 	ceph_decode_timespec(&mtime, &grant->mtime);
2335a8599bd8SSage Weil 	ceph_decode_timespec(&atime, &grant->atime);
2336a8599bd8SSage Weil 	ceph_decode_timespec(&ctime, &grant->ctime);
2337a8599bd8SSage Weil 	ceph_fill_file_time(inode, issued,
2338a8599bd8SSage Weil 			    le32_to_cpu(grant->time_warp_seq), &ctime, &mtime,
2339a8599bd8SSage Weil 			    &atime);
2340a8599bd8SSage Weil 
2341a8599bd8SSage Weil 	/* max size increase? */
2342a8599bd8SSage Weil 	if (max_size != ci->i_max_size) {
2343a8599bd8SSage Weil 		dout("max_size %lld -> %llu\n", ci->i_max_size, max_size);
2344a8599bd8SSage Weil 		ci->i_max_size = max_size;
2345a8599bd8SSage Weil 		if (max_size >= ci->i_wanted_max_size) {
2346a8599bd8SSage Weil 			ci->i_wanted_max_size = 0;  /* reset */
2347a8599bd8SSage Weil 			ci->i_requested_max_size = 0;
2348a8599bd8SSage Weil 		}
2349a8599bd8SSage Weil 		wake = 1;
2350a8599bd8SSage Weil 	}
2351a8599bd8SSage Weil 
2352a8599bd8SSage Weil 	/* check cap bits */
2353a8599bd8SSage Weil 	wanted = __ceph_caps_wanted(ci);
2354a8599bd8SSage Weil 	used = __ceph_caps_used(ci);
2355a8599bd8SSage Weil 	dirty = __ceph_caps_dirty(ci);
2356a8599bd8SSage Weil 	dout(" my wanted = %s, used = %s, dirty %s\n",
2357a8599bd8SSage Weil 	     ceph_cap_string(wanted),
2358a8599bd8SSage Weil 	     ceph_cap_string(used),
2359a8599bd8SSage Weil 	     ceph_cap_string(dirty));
2360a8599bd8SSage Weil 	if (wanted != le32_to_cpu(grant->wanted)) {
2361a8599bd8SSage Weil 		dout("mds wanted %s -> %s\n",
2362a8599bd8SSage Weil 		     ceph_cap_string(le32_to_cpu(grant->wanted)),
2363a8599bd8SSage Weil 		     ceph_cap_string(wanted));
2364a8599bd8SSage Weil 		grant->wanted = cpu_to_le32(wanted);
2365a8599bd8SSage Weil 	}
2366a8599bd8SSage Weil 
2367a8599bd8SSage Weil 	cap->seq = seq;
2368a8599bd8SSage Weil 
2369a8599bd8SSage Weil 	/* file layout may have changed */
2370a8599bd8SSage Weil 	ci->i_layout = grant->layout;
2371a8599bd8SSage Weil 
2372a8599bd8SSage Weil 	/* revocation, grant, or no-op? */
2373a8599bd8SSage Weil 	if (cap->issued & ~newcaps) {
2374a8599bd8SSage Weil 		dout("revocation: %s -> %s\n", ceph_cap_string(cap->issued),
2375a8599bd8SSage Weil 		     ceph_cap_string(newcaps));
2376a8599bd8SSage Weil 		if ((used & ~newcaps) & CEPH_CAP_FILE_BUFFER)
2377a8599bd8SSage Weil 			writeback = 1; /* will delay ack */
2378a8599bd8SSage Weil 		else if (dirty & ~newcaps)
237915637c8bSSage Weil 			check_caps = 1;  /* initiate writeback in check_caps */
23802962507cSSage Weil 		else if (((used & ~newcaps) & (CEPH_CAP_FILE_CACHE|
23812962507cSSage Weil 					       CEPH_CAP_FILE_LAZYIO)) == 0 ||
2382a8599bd8SSage Weil 			   revoked_rdcache)
238315637c8bSSage Weil 			check_caps = 2;     /* send revoke ack in check_caps */
2384a8599bd8SSage Weil 		cap->issued = newcaps;
2385978097c9SSage Weil 		cap->implemented |= newcaps;
2386a8599bd8SSage Weil 	} else if (cap->issued == newcaps) {
2387a8599bd8SSage Weil 		dout("caps unchanged: %s -> %s\n",
2388a8599bd8SSage Weil 		     ceph_cap_string(cap->issued), ceph_cap_string(newcaps));
2389a8599bd8SSage Weil 	} else {
2390a8599bd8SSage Weil 		dout("grant: %s -> %s\n", ceph_cap_string(cap->issued),
2391a8599bd8SSage Weil 		     ceph_cap_string(newcaps));
2392a8599bd8SSage Weil 		cap->issued = newcaps;
2393a8599bd8SSage Weil 		cap->implemented |= newcaps; /* add bits only, to
2394a8599bd8SSage Weil 					      * avoid stepping on a
2395a8599bd8SSage Weil 					      * pending revocation */
2396a8599bd8SSage Weil 		wake = 1;
2397a8599bd8SSage Weil 	}
2398978097c9SSage Weil 	BUG_ON(cap->issued & ~cap->implemented);
2399a8599bd8SSage Weil 
2400a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
24013c6f6b79SSage Weil 	if (writeback)
2402a8599bd8SSage Weil 		/*
2403a8599bd8SSage Weil 		 * queue inode for writeback: we can't actually call
2404a8599bd8SSage Weil 		 * filemap_write_and_wait, etc. from message handler
2405a8599bd8SSage Weil 		 * context.
2406a8599bd8SSage Weil 		 */
24073c6f6b79SSage Weil 		ceph_queue_writeback(inode);
24083c6f6b79SSage Weil 	if (queue_invalidate)
24093c6f6b79SSage Weil 		ceph_queue_invalidate(inode);
2410a8599bd8SSage Weil 	if (wake)
241103066f23SYehuda Sadeh 		wake_up_all(&ci->i_cap_wq);
241215637c8bSSage Weil 
241315637c8bSSage Weil 	if (check_caps == 1)
241415637c8bSSage Weil 		ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
241515637c8bSSage Weil 				session);
241615637c8bSSage Weil 	else if (check_caps == 2)
241715637c8bSSage Weil 		ceph_check_caps(ci, CHECK_CAPS_NODELAY, session);
241815637c8bSSage Weil 	else
241915637c8bSSage Weil 		mutex_unlock(&session->s_mutex);
2420a8599bd8SSage Weil }
2421a8599bd8SSage Weil 
2422a8599bd8SSage Weil /*
2423a8599bd8SSage Weil  * Handle FLUSH_ACK from MDS, indicating that metadata we sent to the
2424a8599bd8SSage Weil  * MDS has been safely committed.
2425a8599bd8SSage Weil  */
24266df058c0SSage Weil static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
2427a8599bd8SSage Weil 				 struct ceph_mds_caps *m,
2428a8599bd8SSage Weil 				 struct ceph_mds_session *session,
2429a8599bd8SSage Weil 				 struct ceph_cap *cap)
2430a8599bd8SSage Weil 	__releases(inode->i_lock)
2431a8599bd8SSage Weil {
2432a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2433640ef79dSCheng Renquan 	struct ceph_mds_client *mdsc = &ceph_sb_to_client(inode->i_sb)->mdsc;
2434a8599bd8SSage Weil 	unsigned seq = le32_to_cpu(m->seq);
2435a8599bd8SSage Weil 	int dirty = le32_to_cpu(m->dirty);
2436a8599bd8SSage Weil 	int cleaned = 0;
2437afcdaea3SSage Weil 	int drop = 0;
2438a8599bd8SSage Weil 	int i;
2439a8599bd8SSage Weil 
2440a8599bd8SSage Weil 	for (i = 0; i < CEPH_CAP_BITS; i++)
2441a8599bd8SSage Weil 		if ((dirty & (1 << i)) &&
2442a8599bd8SSage Weil 		    flush_tid == ci->i_cap_flush_tid[i])
2443a8599bd8SSage Weil 			cleaned |= 1 << i;
2444a8599bd8SSage Weil 
2445a8599bd8SSage Weil 	dout("handle_cap_flush_ack inode %p mds%d seq %d on %s cleaned %s,"
2446a8599bd8SSage Weil 	     " flushing %s -> %s\n",
2447a8599bd8SSage Weil 	     inode, session->s_mds, seq, ceph_cap_string(dirty),
2448a8599bd8SSage Weil 	     ceph_cap_string(cleaned), ceph_cap_string(ci->i_flushing_caps),
2449a8599bd8SSage Weil 	     ceph_cap_string(ci->i_flushing_caps & ~cleaned));
2450a8599bd8SSage Weil 
2451a8599bd8SSage Weil 	if (ci->i_flushing_caps == (ci->i_flushing_caps & ~cleaned))
2452a8599bd8SSage Weil 		goto out;
2453a8599bd8SSage Weil 
2454a8599bd8SSage Weil 	ci->i_flushing_caps &= ~cleaned;
2455a8599bd8SSage Weil 
2456a8599bd8SSage Weil 	spin_lock(&mdsc->cap_dirty_lock);
2457a8599bd8SSage Weil 	if (ci->i_flushing_caps == 0) {
2458a8599bd8SSage Weil 		list_del_init(&ci->i_flushing_item);
2459a8599bd8SSage Weil 		if (!list_empty(&session->s_cap_flushing))
2460a8599bd8SSage Weil 			dout(" mds%d still flushing cap on %p\n",
2461a8599bd8SSage Weil 			     session->s_mds,
2462a8599bd8SSage Weil 			     &list_entry(session->s_cap_flushing.next,
2463a8599bd8SSage Weil 					 struct ceph_inode_info,
2464a8599bd8SSage Weil 					 i_flushing_item)->vfs_inode);
2465a8599bd8SSage Weil 		mdsc->num_cap_flushing--;
246603066f23SYehuda Sadeh 		wake_up_all(&mdsc->cap_flushing_wq);
2467a8599bd8SSage Weil 		dout(" inode %p now !flushing\n", inode);
2468afcdaea3SSage Weil 
2469afcdaea3SSage Weil 		if (ci->i_dirty_caps == 0) {
2470a8599bd8SSage Weil 			dout(" inode %p now clean\n", inode);
2471afcdaea3SSage Weil 			BUG_ON(!list_empty(&ci->i_dirty_item));
2472afcdaea3SSage Weil 			drop = 1;
247376e3b390SSage Weil 		} else {
247476e3b390SSage Weil 			BUG_ON(list_empty(&ci->i_dirty_item));
2475afcdaea3SSage Weil 		}
2476a8599bd8SSage Weil 	}
2477a8599bd8SSage Weil 	spin_unlock(&mdsc->cap_dirty_lock);
247803066f23SYehuda Sadeh 	wake_up_all(&ci->i_cap_wq);
2479a8599bd8SSage Weil 
2480a8599bd8SSage Weil out:
2481a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2482afcdaea3SSage Weil 	if (drop)
2483a8599bd8SSage Weil 		iput(inode);
2484a8599bd8SSage Weil }
2485a8599bd8SSage Weil 
2486a8599bd8SSage Weil /*
2487a8599bd8SSage Weil  * Handle FLUSHSNAP_ACK.  MDS has flushed snap data to disk and we can
2488a8599bd8SSage Weil  * throw away our cap_snap.
2489a8599bd8SSage Weil  *
2490a8599bd8SSage Weil  * Caller hold s_mutex.
2491a8599bd8SSage Weil  */
24926df058c0SSage Weil static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid,
2493a8599bd8SSage Weil 				     struct ceph_mds_caps *m,
2494a8599bd8SSage Weil 				     struct ceph_mds_session *session)
2495a8599bd8SSage Weil {
2496a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2497a8599bd8SSage Weil 	u64 follows = le64_to_cpu(m->snap_follows);
2498a8599bd8SSage Weil 	struct ceph_cap_snap *capsnap;
2499a8599bd8SSage Weil 	int drop = 0;
2500a8599bd8SSage Weil 
2501a8599bd8SSage Weil 	dout("handle_cap_flushsnap_ack inode %p ci %p mds%d follows %lld\n",
2502a8599bd8SSage Weil 	     inode, ci, session->s_mds, follows);
2503a8599bd8SSage Weil 
2504a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2505a8599bd8SSage Weil 	list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
2506a8599bd8SSage Weil 		if (capsnap->follows == follows) {
2507a8599bd8SSage Weil 			if (capsnap->flush_tid != flush_tid) {
2508a8599bd8SSage Weil 				dout(" cap_snap %p follows %lld tid %lld !="
2509a8599bd8SSage Weil 				     " %lld\n", capsnap, follows,
2510a8599bd8SSage Weil 				     flush_tid, capsnap->flush_tid);
2511a8599bd8SSage Weil 				break;
2512a8599bd8SSage Weil 			}
2513a8599bd8SSage Weil 			WARN_ON(capsnap->dirty_pages || capsnap->writing);
2514819ccbfaSSage Weil 			dout(" removing %p cap_snap %p follows %lld\n",
2515819ccbfaSSage Weil 			     inode, capsnap, follows);
2516a8599bd8SSage Weil 			ceph_put_snap_context(capsnap->context);
2517a8599bd8SSage Weil 			list_del(&capsnap->ci_item);
2518a8599bd8SSage Weil 			list_del(&capsnap->flushing_item);
2519a8599bd8SSage Weil 			ceph_put_cap_snap(capsnap);
2520a8599bd8SSage Weil 			drop = 1;
2521a8599bd8SSage Weil 			break;
2522a8599bd8SSage Weil 		} else {
2523a8599bd8SSage Weil 			dout(" skipping cap_snap %p follows %lld\n",
2524a8599bd8SSage Weil 			     capsnap, capsnap->follows);
2525a8599bd8SSage Weil 		}
2526a8599bd8SSage Weil 	}
2527a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2528a8599bd8SSage Weil 	if (drop)
2529a8599bd8SSage Weil 		iput(inode);
2530a8599bd8SSage Weil }
2531a8599bd8SSage Weil 
2532a8599bd8SSage Weil /*
2533a8599bd8SSage Weil  * Handle TRUNC from MDS, indicating file truncation.
2534a8599bd8SSage Weil  *
2535a8599bd8SSage Weil  * caller hold s_mutex.
2536a8599bd8SSage Weil  */
2537a8599bd8SSage Weil static void handle_cap_trunc(struct inode *inode,
2538a8599bd8SSage Weil 			     struct ceph_mds_caps *trunc,
2539a8599bd8SSage Weil 			     struct ceph_mds_session *session)
2540a8599bd8SSage Weil 	__releases(inode->i_lock)
2541a8599bd8SSage Weil {
2542a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2543a8599bd8SSage Weil 	int mds = session->s_mds;
2544a8599bd8SSage Weil 	int seq = le32_to_cpu(trunc->seq);
2545a8599bd8SSage Weil 	u32 truncate_seq = le32_to_cpu(trunc->truncate_seq);
2546a8599bd8SSage Weil 	u64 truncate_size = le64_to_cpu(trunc->truncate_size);
2547a8599bd8SSage Weil 	u64 size = le64_to_cpu(trunc->size);
2548a8599bd8SSage Weil 	int implemented = 0;
2549a8599bd8SSage Weil 	int dirty = __ceph_caps_dirty(ci);
2550a8599bd8SSage Weil 	int issued = __ceph_caps_issued(ceph_inode(inode), &implemented);
2551a8599bd8SSage Weil 	int queue_trunc = 0;
2552a8599bd8SSage Weil 
2553a8599bd8SSage Weil 	issued |= implemented | dirty;
2554a8599bd8SSage Weil 
2555a8599bd8SSage Weil 	dout("handle_cap_trunc inode %p mds%d seq %d to %lld seq %d\n",
2556a8599bd8SSage Weil 	     inode, mds, seq, truncate_size, truncate_seq);
2557a8599bd8SSage Weil 	queue_trunc = ceph_fill_file_size(inode, issued,
2558a8599bd8SSage Weil 					  truncate_seq, truncate_size, size);
2559a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2560a8599bd8SSage Weil 
2561a8599bd8SSage Weil 	if (queue_trunc)
25623c6f6b79SSage Weil 		ceph_queue_vmtruncate(inode);
2563a8599bd8SSage Weil }
2564a8599bd8SSage Weil 
2565a8599bd8SSage Weil /*
2566a8599bd8SSage Weil  * Handle EXPORT from MDS.  Cap is being migrated _from_ this mds to a
2567a8599bd8SSage Weil  * different one.  If we are the most recent migration we've seen (as
2568a8599bd8SSage Weil  * indicated by mseq), make note of the migrating cap bits for the
2569a8599bd8SSage Weil  * duration (until we see the corresponding IMPORT).
2570a8599bd8SSage Weil  *
2571a8599bd8SSage Weil  * caller holds s_mutex
2572a8599bd8SSage Weil  */
2573a8599bd8SSage Weil static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
2574a8599bd8SSage Weil 			      struct ceph_mds_session *session)
2575a8599bd8SSage Weil {
2576a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2577a8599bd8SSage Weil 	int mds = session->s_mds;
2578a8599bd8SSage Weil 	unsigned mseq = le32_to_cpu(ex->migrate_seq);
2579a8599bd8SSage Weil 	struct ceph_cap *cap = NULL, *t;
2580a8599bd8SSage Weil 	struct rb_node *p;
2581a8599bd8SSage Weil 	int remember = 1;
2582a8599bd8SSage Weil 
2583a8599bd8SSage Weil 	dout("handle_cap_export inode %p ci %p mds%d mseq %d\n",
2584a8599bd8SSage Weil 	     inode, ci, mds, mseq);
2585a8599bd8SSage Weil 
2586a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2587a8599bd8SSage Weil 
2588a8599bd8SSage Weil 	/* make sure we haven't seen a higher mseq */
2589a8599bd8SSage Weil 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
2590a8599bd8SSage Weil 		t = rb_entry(p, struct ceph_cap, ci_node);
2591a8599bd8SSage Weil 		if (ceph_seq_cmp(t->mseq, mseq) > 0) {
2592a8599bd8SSage Weil 			dout(" higher mseq on cap from mds%d\n",
2593a8599bd8SSage Weil 			     t->session->s_mds);
2594a8599bd8SSage Weil 			remember = 0;
2595a8599bd8SSage Weil 		}
2596a8599bd8SSage Weil 		if (t->session->s_mds == mds)
2597a8599bd8SSage Weil 			cap = t;
2598a8599bd8SSage Weil 	}
2599a8599bd8SSage Weil 
2600a8599bd8SSage Weil 	if (cap) {
2601a8599bd8SSage Weil 		if (remember) {
2602a8599bd8SSage Weil 			/* make note */
2603a8599bd8SSage Weil 			ci->i_cap_exporting_mds = mds;
2604a8599bd8SSage Weil 			ci->i_cap_exporting_mseq = mseq;
2605a8599bd8SSage Weil 			ci->i_cap_exporting_issued = cap->issued;
2606a8599bd8SSage Weil 		}
26077c1332b8SSage Weil 		__ceph_remove_cap(cap);
2608a8599bd8SSage Weil 	}
26094ea0043aSSage Weil 	/* else, we already released it */
2610a8599bd8SSage Weil 
2611a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2612a8599bd8SSage Weil }
2613a8599bd8SSage Weil 
2614a8599bd8SSage Weil /*
2615a8599bd8SSage Weil  * Handle cap IMPORT.  If there are temp bits from an older EXPORT,
2616a8599bd8SSage Weil  * clean them up.
2617a8599bd8SSage Weil  *
2618a8599bd8SSage Weil  * caller holds s_mutex.
2619a8599bd8SSage Weil  */
2620a8599bd8SSage Weil static void handle_cap_import(struct ceph_mds_client *mdsc,
2621a8599bd8SSage Weil 			      struct inode *inode, struct ceph_mds_caps *im,
2622a8599bd8SSage Weil 			      struct ceph_mds_session *session,
2623a8599bd8SSage Weil 			      void *snaptrace, int snaptrace_len)
2624a8599bd8SSage Weil {
2625a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2626a8599bd8SSage Weil 	int mds = session->s_mds;
2627a8599bd8SSage Weil 	unsigned issued = le32_to_cpu(im->caps);
2628a8599bd8SSage Weil 	unsigned wanted = le32_to_cpu(im->wanted);
2629a8599bd8SSage Weil 	unsigned seq = le32_to_cpu(im->seq);
2630a8599bd8SSage Weil 	unsigned mseq = le32_to_cpu(im->migrate_seq);
2631a8599bd8SSage Weil 	u64 realmino = le64_to_cpu(im->realm);
2632a8599bd8SSage Weil 	u64 cap_id = le64_to_cpu(im->cap_id);
2633a8599bd8SSage Weil 
2634a8599bd8SSage Weil 	if (ci->i_cap_exporting_mds >= 0 &&
2635a8599bd8SSage Weil 	    ceph_seq_cmp(ci->i_cap_exporting_mseq, mseq) < 0) {
2636a8599bd8SSage Weil 		dout("handle_cap_import inode %p ci %p mds%d mseq %d"
2637a8599bd8SSage Weil 		     " - cleared exporting from mds%d\n",
2638a8599bd8SSage Weil 		     inode, ci, mds, mseq,
2639a8599bd8SSage Weil 		     ci->i_cap_exporting_mds);
2640a8599bd8SSage Weil 		ci->i_cap_exporting_issued = 0;
2641a8599bd8SSage Weil 		ci->i_cap_exporting_mseq = 0;
2642a8599bd8SSage Weil 		ci->i_cap_exporting_mds = -1;
2643a8599bd8SSage Weil 	} else {
2644a8599bd8SSage Weil 		dout("handle_cap_import inode %p ci %p mds%d mseq %d\n",
2645a8599bd8SSage Weil 		     inode, ci, mds, mseq);
2646a8599bd8SSage Weil 	}
2647a8599bd8SSage Weil 
2648a8599bd8SSage Weil 	down_write(&mdsc->snap_rwsem);
2649a8599bd8SSage Weil 	ceph_update_snap_trace(mdsc, snaptrace, snaptrace+snaptrace_len,
2650a8599bd8SSage Weil 			       false);
2651a8599bd8SSage Weil 	downgrade_write(&mdsc->snap_rwsem);
2652a8599bd8SSage Weil 	ceph_add_cap(inode, session, cap_id, -1,
2653a8599bd8SSage Weil 		     issued, wanted, seq, mseq, realmino, CEPH_CAP_FLAG_AUTH,
2654a8599bd8SSage Weil 		     NULL /* no caps context */);
2655a8599bd8SSage Weil 	try_flush_caps(inode, session, NULL);
2656a8599bd8SSage Weil 	up_read(&mdsc->snap_rwsem);
2657a8599bd8SSage Weil }
2658a8599bd8SSage Weil 
2659a8599bd8SSage Weil /*
2660a8599bd8SSage Weil  * Handle a caps message from the MDS.
2661a8599bd8SSage Weil  *
2662a8599bd8SSage Weil  * Identify the appropriate session, inode, and call the right handler
2663a8599bd8SSage Weil  * based on the cap op.
2664a8599bd8SSage Weil  */
2665a8599bd8SSage Weil void ceph_handle_caps(struct ceph_mds_session *session,
2666a8599bd8SSage Weil 		      struct ceph_msg *msg)
2667a8599bd8SSage Weil {
2668a8599bd8SSage Weil 	struct ceph_mds_client *mdsc = session->s_mdsc;
2669a8599bd8SSage Weil 	struct super_block *sb = mdsc->client->sb;
2670a8599bd8SSage Weil 	struct inode *inode;
2671a8599bd8SSage Weil 	struct ceph_cap *cap;
2672a8599bd8SSage Weil 	struct ceph_mds_caps *h;
26732600d2ddSSage Weil 	int mds = session->s_mds;
2674a8599bd8SSage Weil 	int op;
26753d7ded4dSSage Weil 	u32 seq, mseq;
2676a8599bd8SSage Weil 	struct ceph_vino vino;
2677a8599bd8SSage Weil 	u64 cap_id;
2678a8599bd8SSage Weil 	u64 size, max_size;
26796df058c0SSage Weil 	u64 tid;
268070edb55bSSage Weil 	void *snaptrace;
2681a8599bd8SSage Weil 
2682a8599bd8SSage Weil 	dout("handle_caps from mds%d\n", mds);
2683a8599bd8SSage Weil 
2684a8599bd8SSage Weil 	/* decode */
26856df058c0SSage Weil 	tid = le64_to_cpu(msg->hdr.tid);
2686a8599bd8SSage Weil 	if (msg->front.iov_len < sizeof(*h))
2687a8599bd8SSage Weil 		goto bad;
2688a8599bd8SSage Weil 	h = msg->front.iov_base;
268970edb55bSSage Weil 	snaptrace = h + 1;
2690a8599bd8SSage Weil 	op = le32_to_cpu(h->op);
2691a8599bd8SSage Weil 	vino.ino = le64_to_cpu(h->ino);
2692a8599bd8SSage Weil 	vino.snap = CEPH_NOSNAP;
2693a8599bd8SSage Weil 	cap_id = le64_to_cpu(h->cap_id);
2694a8599bd8SSage Weil 	seq = le32_to_cpu(h->seq);
26953d7ded4dSSage Weil 	mseq = le32_to_cpu(h->migrate_seq);
2696a8599bd8SSage Weil 	size = le64_to_cpu(h->size);
2697a8599bd8SSage Weil 	max_size = le64_to_cpu(h->max_size);
2698a8599bd8SSage Weil 
2699a8599bd8SSage Weil 	mutex_lock(&session->s_mutex);
2700a8599bd8SSage Weil 	session->s_seq++;
2701a8599bd8SSage Weil 	dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
2702a8599bd8SSage Weil 	     (unsigned)seq);
2703a8599bd8SSage Weil 
2704a8599bd8SSage Weil 	/* lookup ino */
2705a8599bd8SSage Weil 	inode = ceph_find_inode(sb, vino);
2706a8599bd8SSage Weil 	dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino,
2707a8599bd8SSage Weil 	     vino.snap, inode);
2708a8599bd8SSage Weil 	if (!inode) {
2709a8599bd8SSage Weil 		dout(" i don't have ino %llx\n", vino.ino);
27103d7ded4dSSage Weil 
27113d7ded4dSSage Weil 		if (op == CEPH_CAP_OP_IMPORT)
27123d7ded4dSSage Weil 			__queue_cap_release(session, vino.ino, cap_id,
27133d7ded4dSSage Weil 					    mseq, seq);
27143d7ded4dSSage Weil 
27153d7ded4dSSage Weil 		/*
27163d7ded4dSSage Weil 		 * send any full release message to try to move things
27173d7ded4dSSage Weil 		 * along for the mds (who clearly thinks we still have this
27183d7ded4dSSage Weil 		 * cap).
27193d7ded4dSSage Weil 		 */
2720ee6b272bSSage Weil 		ceph_add_cap_releases(mdsc, session);
27213d7ded4dSSage Weil 		ceph_send_cap_releases(mdsc, session);
2722a8599bd8SSage Weil 		goto done;
2723a8599bd8SSage Weil 	}
2724a8599bd8SSage Weil 
2725a8599bd8SSage Weil 	/* these will work even if we don't have a cap yet */
2726a8599bd8SSage Weil 	switch (op) {
2727a8599bd8SSage Weil 	case CEPH_CAP_OP_FLUSHSNAP_ACK:
27286df058c0SSage Weil 		handle_cap_flushsnap_ack(inode, tid, h, session);
2729a8599bd8SSage Weil 		goto done;
2730a8599bd8SSage Weil 
2731a8599bd8SSage Weil 	case CEPH_CAP_OP_EXPORT:
2732a8599bd8SSage Weil 		handle_cap_export(inode, h, session);
2733a8599bd8SSage Weil 		goto done;
2734a8599bd8SSage Weil 
2735a8599bd8SSage Weil 	case CEPH_CAP_OP_IMPORT:
2736a8599bd8SSage Weil 		handle_cap_import(mdsc, inode, h, session,
273770edb55bSSage Weil 				  snaptrace, le32_to_cpu(h->snap_trace_len));
273815637c8bSSage Weil 		ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY,
273915637c8bSSage Weil 				session);
274015637c8bSSage Weil 		goto done_unlocked;
2741a8599bd8SSage Weil 	}
2742a8599bd8SSage Weil 
2743a8599bd8SSage Weil 	/* the rest require a cap */
2744a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2745a8599bd8SSage Weil 	cap = __get_cap_for_mds(ceph_inode(inode), mds);
2746a8599bd8SSage Weil 	if (!cap) {
27479dbd412fSSage Weil 		dout(" no cap on %p ino %llx.%llx from mds%d\n",
2748a8599bd8SSage Weil 		     inode, ceph_ino(inode), ceph_snap(inode), mds);
2749a8599bd8SSage Weil 		spin_unlock(&inode->i_lock);
2750a8599bd8SSage Weil 		goto done;
2751a8599bd8SSage Weil 	}
2752a8599bd8SSage Weil 
2753a8599bd8SSage Weil 	/* note that each of these drops i_lock for us */
2754a8599bd8SSage Weil 	switch (op) {
2755a8599bd8SSage Weil 	case CEPH_CAP_OP_REVOKE:
2756a8599bd8SSage Weil 	case CEPH_CAP_OP_GRANT:
275715637c8bSSage Weil 		handle_cap_grant(inode, h, session, cap, msg->middle);
275815637c8bSSage Weil 		goto done_unlocked;
2759a8599bd8SSage Weil 
2760a8599bd8SSage Weil 	case CEPH_CAP_OP_FLUSH_ACK:
27616df058c0SSage Weil 		handle_cap_flush_ack(inode, tid, h, session, cap);
2762a8599bd8SSage Weil 		break;
2763a8599bd8SSage Weil 
2764a8599bd8SSage Weil 	case CEPH_CAP_OP_TRUNC:
2765a8599bd8SSage Weil 		handle_cap_trunc(inode, h, session);
2766a8599bd8SSage Weil 		break;
2767a8599bd8SSage Weil 
2768a8599bd8SSage Weil 	default:
2769a8599bd8SSage Weil 		spin_unlock(&inode->i_lock);
2770a8599bd8SSage Weil 		pr_err("ceph_handle_caps: unknown cap op %d %s\n", op,
2771a8599bd8SSage Weil 		       ceph_cap_op_name(op));
2772a8599bd8SSage Weil 	}
2773a8599bd8SSage Weil 
2774a8599bd8SSage Weil done:
2775a8599bd8SSage Weil 	mutex_unlock(&session->s_mutex);
277615637c8bSSage Weil done_unlocked:
2777a8599bd8SSage Weil 	if (inode)
2778a8599bd8SSage Weil 		iput(inode);
2779a8599bd8SSage Weil 	return;
2780a8599bd8SSage Weil 
2781a8599bd8SSage Weil bad:
2782a8599bd8SSage Weil 	pr_err("ceph_handle_caps: corrupt message\n");
27839ec7cab1SSage Weil 	ceph_msg_dump(msg);
2784a8599bd8SSage Weil 	return;
2785a8599bd8SSage Weil }
2786a8599bd8SSage Weil 
2787a8599bd8SSage Weil /*
2788a8599bd8SSage Weil  * Delayed work handler to process end of delayed cap release LRU list.
2789a8599bd8SSage Weil  */
2790afcdaea3SSage Weil void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
2791a8599bd8SSage Weil {
2792a8599bd8SSage Weil 	struct ceph_inode_info *ci;
2793a8599bd8SSage Weil 	int flags = CHECK_CAPS_NODELAY;
2794a8599bd8SSage Weil 
2795a8599bd8SSage Weil 	dout("check_delayed_caps\n");
2796a8599bd8SSage Weil 	while (1) {
2797a8599bd8SSage Weil 		spin_lock(&mdsc->cap_delay_lock);
2798a8599bd8SSage Weil 		if (list_empty(&mdsc->cap_delay_list))
2799a8599bd8SSage Weil 			break;
2800a8599bd8SSage Weil 		ci = list_first_entry(&mdsc->cap_delay_list,
2801a8599bd8SSage Weil 				      struct ceph_inode_info,
2802a8599bd8SSage Weil 				      i_cap_delay_list);
2803a8599bd8SSage Weil 		if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 &&
2804a8599bd8SSage Weil 		    time_before(jiffies, ci->i_hold_caps_max))
2805a8599bd8SSage Weil 			break;
2806a8599bd8SSage Weil 		list_del_init(&ci->i_cap_delay_list);
2807a8599bd8SSage Weil 		spin_unlock(&mdsc->cap_delay_lock);
2808a8599bd8SSage Weil 		dout("check_delayed_caps on %p\n", &ci->vfs_inode);
2809a8599bd8SSage Weil 		ceph_check_caps(ci, flags, NULL);
2810a8599bd8SSage Weil 	}
2811a8599bd8SSage Weil 	spin_unlock(&mdsc->cap_delay_lock);
2812a8599bd8SSage Weil }
2813a8599bd8SSage Weil 
2814a8599bd8SSage Weil /*
2815afcdaea3SSage Weil  * Flush all dirty caps to the mds
2816afcdaea3SSage Weil  */
2817afcdaea3SSage Weil void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
2818afcdaea3SSage Weil {
2819e9964c10SSage Weil 	struct ceph_inode_info *ci, *nci = NULL;
2820e9964c10SSage Weil 	struct inode *inode, *ninode = NULL;
2821e9964c10SSage Weil 	struct list_head *p, *n;
2822afcdaea3SSage Weil 
2823afcdaea3SSage Weil 	dout("flush_dirty_caps\n");
2824afcdaea3SSage Weil 	spin_lock(&mdsc->cap_dirty_lock);
2825e9964c10SSage Weil 	list_for_each_safe(p, n, &mdsc->cap_dirty) {
2826e9964c10SSage Weil 		if (nci) {
2827e9964c10SSage Weil 			ci = nci;
2828e9964c10SSage Weil 			inode = ninode;
2829e9964c10SSage Weil 			ci->i_ceph_flags &= ~CEPH_I_NOFLUSH;
2830e9964c10SSage Weil 			dout("flush_dirty_caps inode %p (was next inode)\n",
2831e9964c10SSage Weil 			     inode);
2832e9964c10SSage Weil 		} else {
2833e9964c10SSage Weil 			ci = list_entry(p, struct ceph_inode_info,
2834afcdaea3SSage Weil 					i_dirty_item);
2835afcdaea3SSage Weil 			inode = igrab(&ci->vfs_inode);
2836e9964c10SSage Weil 			BUG_ON(!inode);
2837e9964c10SSage Weil 			dout("flush_dirty_caps inode %p\n", inode);
2838e9964c10SSage Weil 		}
2839e9964c10SSage Weil 		if (n != &mdsc->cap_dirty) {
2840e9964c10SSage Weil 			nci = list_entry(n, struct ceph_inode_info,
2841e9964c10SSage Weil 					 i_dirty_item);
2842e9964c10SSage Weil 			ninode = igrab(&nci->vfs_inode);
2843e9964c10SSage Weil 			BUG_ON(!ninode);
2844e9964c10SSage Weil 			nci->i_ceph_flags |= CEPH_I_NOFLUSH;
2845e9964c10SSage Weil 			dout("flush_dirty_caps next inode %p, noflush\n",
2846e9964c10SSage Weil 			     ninode);
2847e9964c10SSage Weil 		} else {
2848e9964c10SSage Weil 			nci = NULL;
2849e9964c10SSage Weil 			ninode = NULL;
2850e9964c10SSage Weil 		}
2851afcdaea3SSage Weil 		spin_unlock(&mdsc->cap_dirty_lock);
2852afcdaea3SSage Weil 		if (inode) {
2853afcdaea3SSage Weil 			ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH,
2854afcdaea3SSage Weil 					NULL);
2855afcdaea3SSage Weil 			iput(inode);
2856afcdaea3SSage Weil 		}
2857afcdaea3SSage Weil 		spin_lock(&mdsc->cap_dirty_lock);
2858afcdaea3SSage Weil 	}
2859afcdaea3SSage Weil 	spin_unlock(&mdsc->cap_dirty_lock);
2860afcdaea3SSage Weil }
2861afcdaea3SSage Weil 
2862afcdaea3SSage Weil /*
2863a8599bd8SSage Weil  * Drop open file reference.  If we were the last open file,
2864a8599bd8SSage Weil  * we may need to release capabilities to the MDS (or schedule
2865a8599bd8SSage Weil  * their delayed release).
2866a8599bd8SSage Weil  */
2867a8599bd8SSage Weil void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
2868a8599bd8SSage Weil {
2869a8599bd8SSage Weil 	struct inode *inode = &ci->vfs_inode;
2870a8599bd8SSage Weil 	int last = 0;
2871a8599bd8SSage Weil 
2872a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2873a8599bd8SSage Weil 	dout("put_fmode %p fmode %d %d -> %d\n", inode, fmode,
2874a8599bd8SSage Weil 	     ci->i_nr_by_mode[fmode], ci->i_nr_by_mode[fmode]-1);
2875a8599bd8SSage Weil 	BUG_ON(ci->i_nr_by_mode[fmode] == 0);
2876a8599bd8SSage Weil 	if (--ci->i_nr_by_mode[fmode] == 0)
2877a8599bd8SSage Weil 		last++;
2878a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2879a8599bd8SSage Weil 
2880a8599bd8SSage Weil 	if (last && ci->i_vino.snap == CEPH_NOSNAP)
2881a8599bd8SSage Weil 		ceph_check_caps(ci, 0, NULL);
2882a8599bd8SSage Weil }
2883a8599bd8SSage Weil 
2884a8599bd8SSage Weil /*
2885a8599bd8SSage Weil  * Helpers for embedding cap and dentry lease releases into mds
2886a8599bd8SSage Weil  * requests.
2887a8599bd8SSage Weil  *
2888a8599bd8SSage Weil  * @force is used by dentry_release (below) to force inclusion of a
2889a8599bd8SSage Weil  * record for the directory inode, even when there aren't any caps to
2890a8599bd8SSage Weil  * drop.
2891a8599bd8SSage Weil  */
2892a8599bd8SSage Weil int ceph_encode_inode_release(void **p, struct inode *inode,
2893a8599bd8SSage Weil 			      int mds, int drop, int unless, int force)
2894a8599bd8SSage Weil {
2895a8599bd8SSage Weil 	struct ceph_inode_info *ci = ceph_inode(inode);
2896a8599bd8SSage Weil 	struct ceph_cap *cap;
2897a8599bd8SSage Weil 	struct ceph_mds_request_release *rel = *p;
2898ec97f88bSSage Weil 	int used, dirty;
2899a8599bd8SSage Weil 	int ret = 0;
2900a8599bd8SSage Weil 
2901a8599bd8SSage Weil 	spin_lock(&inode->i_lock);
2902916623daSSage Weil 	used = __ceph_caps_used(ci);
2903ec97f88bSSage Weil 	dirty = __ceph_caps_dirty(ci);
2904916623daSSage Weil 
2905ec97f88bSSage Weil 	dout("encode_inode_release %p mds%d used|dirty %s drop %s unless %s\n",
2906ec97f88bSSage Weil 	     inode, mds, ceph_cap_string(used|dirty), ceph_cap_string(drop),
2907916623daSSage Weil 	     ceph_cap_string(unless));
2908916623daSSage Weil 
2909ec97f88bSSage Weil 	/* only drop unused, clean caps */
2910ec97f88bSSage Weil 	drop &= ~(used | dirty);
2911916623daSSage Weil 
2912a8599bd8SSage Weil 	cap = __get_cap_for_mds(ci, mds);
2913a8599bd8SSage Weil 	if (cap && __cap_is_valid(cap)) {
2914a8599bd8SSage Weil 		if (force ||
2915a8599bd8SSage Weil 		    ((cap->issued & drop) &&
2916a8599bd8SSage Weil 		     (cap->issued & unless) == 0)) {
2917a8599bd8SSage Weil 			if ((cap->issued & drop) &&
2918a8599bd8SSage Weil 			    (cap->issued & unless) == 0) {
2919a8599bd8SSage Weil 				dout("encode_inode_release %p cap %p %s -> "
2920a8599bd8SSage Weil 				     "%s\n", inode, cap,
2921a8599bd8SSage Weil 				     ceph_cap_string(cap->issued),
2922a8599bd8SSage Weil 				     ceph_cap_string(cap->issued & ~drop));
2923a8599bd8SSage Weil 				cap->issued &= ~drop;
2924a8599bd8SSage Weil 				cap->implemented &= ~drop;
2925a8599bd8SSage Weil 				if (ci->i_ceph_flags & CEPH_I_NODELAY) {
2926a8599bd8SSage Weil 					int wanted = __ceph_caps_wanted(ci);
2927a8599bd8SSage Weil 					dout("  wanted %s -> %s (act %s)\n",
2928a8599bd8SSage Weil 					     ceph_cap_string(cap->mds_wanted),
2929a8599bd8SSage Weil 					     ceph_cap_string(cap->mds_wanted &
2930a8599bd8SSage Weil 							     ~wanted),
2931a8599bd8SSage Weil 					     ceph_cap_string(wanted));
2932a8599bd8SSage Weil 					cap->mds_wanted &= wanted;
2933a8599bd8SSage Weil 				}
2934a8599bd8SSage Weil 			} else {
2935a8599bd8SSage Weil 				dout("encode_inode_release %p cap %p %s"
2936a8599bd8SSage Weil 				     " (force)\n", inode, cap,
2937a8599bd8SSage Weil 				     ceph_cap_string(cap->issued));
2938a8599bd8SSage Weil 			}
2939a8599bd8SSage Weil 
2940a8599bd8SSage Weil 			rel->ino = cpu_to_le64(ceph_ino(inode));
2941a8599bd8SSage Weil 			rel->cap_id = cpu_to_le64(cap->cap_id);
2942a8599bd8SSage Weil 			rel->seq = cpu_to_le32(cap->seq);
2943a8599bd8SSage Weil 			rel->issue_seq = cpu_to_le32(cap->issue_seq),
2944a8599bd8SSage Weil 			rel->mseq = cpu_to_le32(cap->mseq);
2945a8599bd8SSage Weil 			rel->caps = cpu_to_le32(cap->issued);
2946a8599bd8SSage Weil 			rel->wanted = cpu_to_le32(cap->mds_wanted);
2947a8599bd8SSage Weil 			rel->dname_len = 0;
2948a8599bd8SSage Weil 			rel->dname_seq = 0;
2949a8599bd8SSage Weil 			*p += sizeof(*rel);
2950a8599bd8SSage Weil 			ret = 1;
2951a8599bd8SSage Weil 		} else {
2952a8599bd8SSage Weil 			dout("encode_inode_release %p cap %p %s\n",
2953a8599bd8SSage Weil 			     inode, cap, ceph_cap_string(cap->issued));
2954a8599bd8SSage Weil 		}
2955a8599bd8SSage Weil 	}
2956a8599bd8SSage Weil 	spin_unlock(&inode->i_lock);
2957a8599bd8SSage Weil 	return ret;
2958a8599bd8SSage Weil }
2959a8599bd8SSage Weil 
2960a8599bd8SSage Weil int ceph_encode_dentry_release(void **p, struct dentry *dentry,
2961a8599bd8SSage Weil 			       int mds, int drop, int unless)
2962a8599bd8SSage Weil {
2963a8599bd8SSage Weil 	struct inode *dir = dentry->d_parent->d_inode;
2964a8599bd8SSage Weil 	struct ceph_mds_request_release *rel = *p;
2965a8599bd8SSage Weil 	struct ceph_dentry_info *di = ceph_dentry(dentry);
2966a8599bd8SSage Weil 	int force = 0;
2967a8599bd8SSage Weil 	int ret;
2968a8599bd8SSage Weil 
2969a8599bd8SSage Weil 	/*
2970a8599bd8SSage Weil 	 * force an record for the directory caps if we have a dentry lease.
2971a8599bd8SSage Weil 	 * this is racy (can't take i_lock and d_lock together), but it
2972a8599bd8SSage Weil 	 * doesn't have to be perfect; the mds will revoke anything we don't
2973a8599bd8SSage Weil 	 * release.
2974a8599bd8SSage Weil 	 */
2975a8599bd8SSage Weil 	spin_lock(&dentry->d_lock);
2976a8599bd8SSage Weil 	if (di->lease_session && di->lease_session->s_mds == mds)
2977a8599bd8SSage Weil 		force = 1;
2978a8599bd8SSage Weil 	spin_unlock(&dentry->d_lock);
2979a8599bd8SSage Weil 
2980a8599bd8SSage Weil 	ret = ceph_encode_inode_release(p, dir, mds, drop, unless, force);
2981a8599bd8SSage Weil 
2982a8599bd8SSage Weil 	spin_lock(&dentry->d_lock);
2983a8599bd8SSage Weil 	if (ret && di->lease_session && di->lease_session->s_mds == mds) {
2984a8599bd8SSage Weil 		dout("encode_dentry_release %p mds%d seq %d\n",
2985a8599bd8SSage Weil 		     dentry, mds, (int)di->lease_seq);
2986a8599bd8SSage Weil 		rel->dname_len = cpu_to_le32(dentry->d_name.len);
2987a8599bd8SSage Weil 		memcpy(*p, dentry->d_name.name, dentry->d_name.len);
2988a8599bd8SSage Weil 		*p += dentry->d_name.len;
2989a8599bd8SSage Weil 		rel->dname_seq = cpu_to_le32(di->lease_seq);
29901dadcce3SSage Weil 		__ceph_mdsc_drop_dentry_lease(dentry);
2991a8599bd8SSage Weil 	}
2992a8599bd8SSage Weil 	spin_unlock(&dentry->d_lock);
2993a8599bd8SSage Weil 	return ret;
2994a8599bd8SSage Weil }
2995