1// SPDX-License-Identifier: GPL-2.0
2/*
3 * quota.c - CephFS quota
4 *
5 * Copyright (C) 2017-2018 SUSE
6 */
7
8#include <linux/statfs.h>
9
10#include "super.h"
11#include "mds_client.h"
12
13void ceph_adjust_quota_realms_count(struct inode *inode, bool inc)
14{
15 struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(sb: inode->i_sb);
16 if (inc)
17 atomic64_inc(v: &mdsc->quotarealms_count);
18 else
19 atomic64_dec(v: &mdsc->quotarealms_count);
20}
21
22static inline bool ceph_has_realms_with_quotas(struct inode *inode)
23{
24 struct super_block *sb = inode->i_sb;
25 struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(sb);
26 struct inode *root = d_inode(dentry: sb->s_root);
27
28 if (atomic64_read(v: &mdsc->quotarealms_count) > 0)
29 return true;
30 /* if root is the real CephFS root, we don't have quota realms */
31 if (root && ceph_ino(inode: root) == CEPH_INO_ROOT)
32 return false;
33 /* MDS stray dirs have no quota realms */
34 if (ceph_vino_is_reserved(vino: ceph_inode(inode)->i_vino))
35 return false;
36 /* otherwise, we can't know for sure */
37 return true;
38}
39
40void ceph_handle_quota(struct ceph_mds_client *mdsc,
41 struct ceph_mds_session *session,
42 struct ceph_msg *msg)
43{
44 struct super_block *sb = mdsc->fsc->sb;
45 struct ceph_mds_quota *h = msg->front.iov_base;
46 struct ceph_client *cl = mdsc->fsc->client;
47 struct ceph_vino vino;
48 struct inode *inode;
49 struct ceph_inode_info *ci;
50
51 if (!ceph_inc_mds_stopping_blocker(mdsc, session))
52 return;
53
54 if (msg->front.iov_len < sizeof(*h)) {
55 pr_err_client(cl, "corrupt message mds%d len %d\n",
56 session->s_mds, (int)msg->front.iov_len);
57 ceph_msg_dump(msg);
58 goto out;
59 }
60
61 /* lookup inode */
62 vino.ino = le64_to_cpu(h->ino);
63 vino.snap = CEPH_NOSNAP;
64 inode = ceph_find_inode(sb, vino);
65 if (!inode) {
66 pr_warn_client(cl, "failed to find inode %llx\n", vino.ino);
67 goto out;
68 }
69 ci = ceph_inode(inode);
70
71 spin_lock(lock: &ci->i_ceph_lock);
72 ci->i_rbytes = le64_to_cpu(h->rbytes);
73 ci->i_rfiles = le64_to_cpu(h->rfiles);
74 ci->i_rsubdirs = le64_to_cpu(h->rsubdirs);
75 __ceph_update_quota(ci, le64_to_cpu(h->max_bytes),
76 le64_to_cpu(h->max_files));
77 spin_unlock(lock: &ci->i_ceph_lock);
78
79 iput(inode);
80out:
81 ceph_dec_mds_stopping_blocker(mdsc);
82}
83
84static struct ceph_quotarealm_inode *
85find_quotarealm_inode(struct ceph_mds_client *mdsc, u64 ino)
86{
87 struct ceph_quotarealm_inode *qri = NULL;
88 struct rb_node **node, *parent = NULL;
89 struct ceph_client *cl = mdsc->fsc->client;
90
91 mutex_lock(&mdsc->quotarealms_inodes_mutex);
92 node = &(mdsc->quotarealms_inodes.rb_node);
93 while (*node) {
94 parent = *node;
95 qri = container_of(*node, struct ceph_quotarealm_inode, node);
96
97 if (ino < qri->ino)
98 node = &((*node)->rb_left);
99 else if (ino > qri->ino)
100 node = &((*node)->rb_right);
101 else
102 break;
103 }
104 if (!qri || (qri->ino != ino)) {
105 /* Not found, create a new one and insert it */
106 qri = kmalloc(size: sizeof(*qri), GFP_KERNEL);
107 if (qri) {
108 qri->ino = ino;
109 qri->inode = NULL;
110 qri->timeout = 0;
111 mutex_init(&qri->mutex);
112 rb_link_node(node: &qri->node, parent, rb_link: node);
113 rb_insert_color(&qri->node, &mdsc->quotarealms_inodes);
114 } else
115 pr_warn_client(cl, "Failed to alloc quotarealms_inode\n");
116 }
117 mutex_unlock(lock: &mdsc->quotarealms_inodes_mutex);
118
119 return qri;
120}
121
122/*
123 * This function will try to lookup a realm inode which isn't visible in the
124 * filesystem mountpoint. A list of these kind of inodes (not visible) is
125 * maintained in the mdsc and freed only when the filesystem is umounted.
126 *
127 * Note that these inodes are kept in this list even if the lookup fails, which
128 * allows to prevent useless lookup requests.
129 */
130static struct inode *lookup_quotarealm_inode(struct ceph_mds_client *mdsc,
131 struct super_block *sb,
132 struct ceph_snap_realm *realm)
133{
134 struct ceph_client *cl = mdsc->fsc->client;
135 struct ceph_quotarealm_inode *qri;
136 struct inode *in;
137
138 qri = find_quotarealm_inode(mdsc, ino: realm->ino);
139 if (!qri)
140 return NULL;
141
142 mutex_lock(&qri->mutex);
143 if (qri->inode && ceph_is_any_caps(inode: qri->inode)) {
144 /* A request has already returned the inode */
145 mutex_unlock(lock: &qri->mutex);
146 return qri->inode;
147 }
148 /* Check if this inode lookup has failed recently */
149 if (qri->timeout &&
150 time_before_eq(jiffies, qri->timeout)) {
151 mutex_unlock(lock: &qri->mutex);
152 return NULL;
153 }
154 if (qri->inode) {
155 /* get caps */
156 int ret = __ceph_do_getattr(inode: qri->inode, NULL,
157 CEPH_STAT_CAP_INODE, force: true);
158 if (ret >= 0)
159 in = qri->inode;
160 else
161 in = ERR_PTR(error: ret);
162 } else {
163 in = ceph_lookup_inode(sb, ino: realm->ino);
164 }
165
166 if (IS_ERR(ptr: in)) {
167 doutc(cl, "Can't lookup inode %llx (err: %ld)\n", realm->ino,
168 PTR_ERR(in));
169 qri->timeout = jiffies + msecs_to_jiffies(m: 60 * 1000); /* XXX */
170 } else {
171 qri->timeout = 0;
172 qri->inode = in;
173 }
174 mutex_unlock(lock: &qri->mutex);
175
176 return in;
177}
178
179void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc)
180{
181 struct ceph_quotarealm_inode *qri;
182 struct rb_node *node;
183
184 /*
185 * It should now be safe to clean quotarealms_inode tree without holding
186 * mdsc->quotarealms_inodes_mutex...
187 */
188 mutex_lock(&mdsc->quotarealms_inodes_mutex);
189 while (!RB_EMPTY_ROOT(&mdsc->quotarealms_inodes)) {
190 node = rb_first(&mdsc->quotarealms_inodes);
191 qri = rb_entry(node, struct ceph_quotarealm_inode, node);
192 rb_erase(node, &mdsc->quotarealms_inodes);
193 iput(qri->inode);
194 kfree(objp: qri);
195 }
196 mutex_unlock(lock: &mdsc->quotarealms_inodes_mutex);
197}
198
199/*
200 * This function walks through the snaprealm for an inode and set the
201 * realmp with the first snaprealm that has quotas set (max_files,
202 * max_bytes, or any, depending on the 'which_quota' argument). If the root is
203 * reached, set the realmp with the root ceph_snap_realm instead.
204 *
205 * Note that the caller is responsible for calling ceph_put_snap_realm() on the
206 * returned realm.
207 *
208 * Callers of this function need to hold mdsc->snap_rwsem. However, if there's
209 * a need to do an inode lookup, this rwsem will be temporarily dropped. Hence
210 * the 'retry' argument: if rwsem needs to be dropped and 'retry' is 'false'
211 * this function will return -EAGAIN; otherwise, the snaprealms walk-through
212 * will be restarted.
213 */
214static int get_quota_realm(struct ceph_mds_client *mdsc, struct inode *inode,
215 enum quota_get_realm which_quota,
216 struct ceph_snap_realm **realmp, bool retry)
217{
218 struct ceph_client *cl = mdsc->fsc->client;
219 struct ceph_inode_info *ci = NULL;
220 struct ceph_snap_realm *realm, *next;
221 struct inode *in;
222 bool has_quota;
223
224 if (realmp)
225 *realmp = NULL;
226 if (ceph_snap(inode) != CEPH_NOSNAP)
227 return 0;
228
229restart:
230 realm = ceph_inode(inode)->i_snap_realm;
231 if (realm)
232 ceph_get_snap_realm(mdsc, realm);
233 else
234 pr_err_ratelimited_client(cl,
235 "%p %llx.%llx null i_snap_realm\n",
236 inode, ceph_vinop(inode));
237 while (realm) {
238 bool has_inode;
239
240 spin_lock(lock: &realm->inodes_with_caps_lock);
241 has_inode = realm->inode;
242 in = has_inode ? igrab(realm->inode) : NULL;
243 spin_unlock(lock: &realm->inodes_with_caps_lock);
244 if (has_inode && !in)
245 break;
246 if (!in) {
247 up_read(sem: &mdsc->snap_rwsem);
248 in = lookup_quotarealm_inode(mdsc, sb: inode->i_sb, realm);
249 down_read(sem: &mdsc->snap_rwsem);
250 if (IS_ERR_OR_NULL(ptr: in))
251 break;
252 ceph_put_snap_realm(mdsc, realm);
253 if (!retry)
254 return -EAGAIN;
255 goto restart;
256 }
257
258 ci = ceph_inode(inode: in);
259 has_quota = __ceph_has_quota(ci, which: which_quota);
260 iput(in);
261
262 next = realm->parent;
263 if (has_quota || !next) {
264 if (realmp)
265 *realmp = realm;
266 return 0;
267 }
268
269 ceph_get_snap_realm(mdsc, realm: next);
270 ceph_put_snap_realm(mdsc, realm);
271 realm = next;
272 }
273 if (realm)
274 ceph_put_snap_realm(mdsc, realm);
275
276 return 0;
277}
278
279bool ceph_quota_is_same_realm(struct inode *old, struct inode *new)
280{
281 struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(sb: old->i_sb);
282 struct ceph_snap_realm *old_realm, *new_realm;
283 bool is_same;
284 int ret;
285
286restart:
287 /*
288 * We need to lookup 2 quota realms atomically, i.e. with snap_rwsem.
289 * However, get_quota_realm may drop it temporarily. By setting the
290 * 'retry' parameter to 'false', we'll get -EAGAIN if the rwsem was
291 * dropped and we can then restart the whole operation.
292 */
293 down_read(sem: &mdsc->snap_rwsem);
294 get_quota_realm(mdsc, inode: old, which_quota: QUOTA_GET_ANY, realmp: &old_realm, retry: true);
295 ret = get_quota_realm(mdsc, inode: new, which_quota: QUOTA_GET_ANY, realmp: &new_realm, retry: false);
296 if (ret == -EAGAIN) {
297 up_read(sem: &mdsc->snap_rwsem);
298 if (old_realm)
299 ceph_put_snap_realm(mdsc, realm: old_realm);
300 goto restart;
301 }
302 is_same = (old_realm == new_realm);
303 up_read(sem: &mdsc->snap_rwsem);
304
305 if (old_realm)
306 ceph_put_snap_realm(mdsc, realm: old_realm);
307 if (new_realm)
308 ceph_put_snap_realm(mdsc, realm: new_realm);
309
310 return is_same;
311}
312
313enum quota_check_op {
314 QUOTA_CHECK_MAX_FILES_OP, /* check quota max_files limit */
315 QUOTA_CHECK_MAX_BYTES_OP, /* check quota max_files limit */
316 QUOTA_CHECK_MAX_BYTES_APPROACHING_OP /* check if quota max_files
317 limit is approaching */
318};
319
320/*
321 * check_quota_exceeded() will walk up the snaprealm hierarchy and, for each
322 * realm, it will execute quota check operation defined by the 'op' parameter.
323 * The snaprealm walk is interrupted if the quota check detects that the quota
324 * is exceeded or if the root inode is reached.
325 */
326static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op,
327 loff_t delta)
328{
329 struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(sb: inode->i_sb);
330 struct ceph_client *cl = mdsc->fsc->client;
331 struct ceph_inode_info *ci;
332 struct ceph_snap_realm *realm, *next;
333 struct inode *in;
334 u64 max, rvalue;
335 bool exceeded = false;
336
337 if (ceph_snap(inode) != CEPH_NOSNAP)
338 return false;
339
340 down_read(sem: &mdsc->snap_rwsem);
341restart:
342 realm = ceph_inode(inode)->i_snap_realm;
343 if (realm)
344 ceph_get_snap_realm(mdsc, realm);
345 else
346 pr_err_ratelimited_client(cl,
347 "%p %llx.%llx null i_snap_realm\n",
348 inode, ceph_vinop(inode));
349 while (realm) {
350 bool has_inode;
351
352 spin_lock(lock: &realm->inodes_with_caps_lock);
353 has_inode = realm->inode;
354 in = has_inode ? igrab(realm->inode) : NULL;
355 spin_unlock(lock: &realm->inodes_with_caps_lock);
356 if (has_inode && !in)
357 break;
358 if (!in) {
359 up_read(sem: &mdsc->snap_rwsem);
360 in = lookup_quotarealm_inode(mdsc, sb: inode->i_sb, realm);
361 down_read(sem: &mdsc->snap_rwsem);
362 if (IS_ERR_OR_NULL(ptr: in))
363 break;
364 ceph_put_snap_realm(mdsc, realm);
365 goto restart;
366 }
367 ci = ceph_inode(inode: in);
368 spin_lock(lock: &ci->i_ceph_lock);
369 if (op == QUOTA_CHECK_MAX_FILES_OP) {
370 max = ci->i_max_files;
371 rvalue = ci->i_rfiles + ci->i_rsubdirs;
372 } else {
373 max = ci->i_max_bytes;
374 rvalue = ci->i_rbytes;
375 }
376 spin_unlock(lock: &ci->i_ceph_lock);
377 switch (op) {
378 case QUOTA_CHECK_MAX_FILES_OP:
379 case QUOTA_CHECK_MAX_BYTES_OP:
380 exceeded = (max && (rvalue + delta > max));
381 break;
382 case QUOTA_CHECK_MAX_BYTES_APPROACHING_OP:
383 if (max) {
384 if (rvalue >= max)
385 exceeded = true;
386 else {
387 /*
388 * when we're writing more that 1/16th
389 * of the available space
390 */
391 exceeded =
392 (((max - rvalue) >> 4) < delta);
393 }
394 }
395 break;
396 default:
397 /* Shouldn't happen */
398 pr_warn_client(cl, "Invalid quota check op (%d)\n", op);
399 exceeded = true; /* Just break the loop */
400 }
401 iput(in);
402
403 next = realm->parent;
404 if (exceeded || !next)
405 break;
406 ceph_get_snap_realm(mdsc, realm: next);
407 ceph_put_snap_realm(mdsc, realm);
408 realm = next;
409 }
410 if (realm)
411 ceph_put_snap_realm(mdsc, realm);
412 up_read(sem: &mdsc->snap_rwsem);
413
414 return exceeded;
415}
416
417/*
418 * ceph_quota_is_max_files_exceeded - check if we can create a new file
419 * @inode: directory where a new file is being created
420 *
421 * This functions returns true is max_files quota allows a new file to be
422 * created. It is necessary to walk through the snaprealm hierarchy (until the
423 * FS root) to check all realms with quotas set.
424 */
425bool ceph_quota_is_max_files_exceeded(struct inode *inode)
426{
427 if (!ceph_has_realms_with_quotas(inode))
428 return false;
429
430 WARN_ON(!S_ISDIR(inode->i_mode));
431
432 return check_quota_exceeded(inode, op: QUOTA_CHECK_MAX_FILES_OP, delta: 1);
433}
434
435/*
436 * ceph_quota_is_max_bytes_exceeded - check if we can write to a file
437 * @inode: inode being written
438 * @newsize: new size if write succeeds
439 *
440 * This functions returns true is max_bytes quota allows a file size to reach
441 * @newsize; it returns false otherwise.
442 */
443bool ceph_quota_is_max_bytes_exceeded(struct inode *inode, loff_t newsize)
444{
445 loff_t size = i_size_read(inode);
446
447 if (!ceph_has_realms_with_quotas(inode))
448 return false;
449
450 /* return immediately if we're decreasing file size */
451 if (newsize <= size)
452 return false;
453
454 return check_quota_exceeded(inode, op: QUOTA_CHECK_MAX_BYTES_OP, delta: (newsize - size));
455}
456
457/*
458 * ceph_quota_is_max_bytes_approaching - check if we're reaching max_bytes
459 * @inode: inode being written
460 * @newsize: new size if write succeeds
461 *
462 * This function returns true if the new file size @newsize will be consuming
463 * more than 1/16th of the available quota space; it returns false otherwise.
464 */
465bool ceph_quota_is_max_bytes_approaching(struct inode *inode, loff_t newsize)
466{
467 loff_t size = ceph_inode(inode)->i_reported_size;
468
469 if (!ceph_has_realms_with_quotas(inode))
470 return false;
471
472 /* return immediately if we're decreasing file size */
473 if (newsize <= size)
474 return false;
475
476 return check_quota_exceeded(inode, op: QUOTA_CHECK_MAX_BYTES_APPROACHING_OP,
477 delta: (newsize - size));
478}
479
480/*
481 * ceph_quota_update_statfs - if root has quota update statfs with quota status
482 * @fsc: filesystem client instance
483 * @buf: statfs to update
484 *
485 * If the mounted filesystem root has max_bytes quota set, update the filesystem
486 * statistics with the quota status.
487 *
488 * This function returns true if the stats have been updated, false otherwise.
489 */
490bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf)
491{
492 struct ceph_mds_client *mdsc = fsc->mdsc;
493 struct ceph_inode_info *ci;
494 struct ceph_snap_realm *realm;
495 struct inode *in;
496 u64 total = 0, used, free;
497 bool is_updated = false;
498
499 down_read(sem: &mdsc->snap_rwsem);
500 get_quota_realm(mdsc, inode: d_inode(dentry: fsc->sb->s_root), which_quota: QUOTA_GET_MAX_BYTES,
501 realmp: &realm, retry: true);
502 up_read(sem: &mdsc->snap_rwsem);
503 if (!realm)
504 return false;
505
506 spin_lock(lock: &realm->inodes_with_caps_lock);
507 in = realm->inode ? igrab(realm->inode) : NULL;
508 spin_unlock(lock: &realm->inodes_with_caps_lock);
509 if (in) {
510 ci = ceph_inode(inode: in);
511 spin_lock(lock: &ci->i_ceph_lock);
512 if (ci->i_max_bytes) {
513 total = ci->i_max_bytes >> CEPH_BLOCK_SHIFT;
514 used = ci->i_rbytes >> CEPH_BLOCK_SHIFT;
515 /* For quota size less than 4MB, use 4KB block size */
516 if (!total) {
517 total = ci->i_max_bytes >> CEPH_4K_BLOCK_SHIFT;
518 used = ci->i_rbytes >> CEPH_4K_BLOCK_SHIFT;
519 buf->f_frsize = 1 << CEPH_4K_BLOCK_SHIFT;
520 }
521 /* It is possible for a quota to be exceeded.
522 * Report 'zero' in that case
523 */
524 free = total > used ? total - used : 0;
525 /* For quota size less than 4KB, report the
526 * total=used=4KB,free=0 when quota is full
527 * and total=free=4KB, used=0 otherwise */
528 if (!total) {
529 total = 1;
530 free = ci->i_max_bytes > ci->i_rbytes ? 1 : 0;
531 buf->f_frsize = 1 << CEPH_4K_BLOCK_SHIFT;
532 }
533 }
534 spin_unlock(lock: &ci->i_ceph_lock);
535 if (total) {
536 buf->f_blocks = total;
537 buf->f_bfree = free;
538 buf->f_bavail = free;
539 is_updated = true;
540 }
541 iput(in);
542 }
543 ceph_put_snap_realm(mdsc, realm);
544
545 return is_updated;
546}
547
548

source code of linux/fs/ceph/quota.c