1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * quota.c - CephFS quota 4 * 5 * Copyright (C) 2017-2018 SUSE 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2 10 * of the License, or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include <linux/statfs.h> 22 23 #include "super.h" 24 #include "mds_client.h" 25 26 void ceph_adjust_quota_realms_count(struct inode *inode, bool inc) 27 { 28 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; 29 if (inc) 30 atomic64_inc(&mdsc->quotarealms_count); 31 else 32 atomic64_dec(&mdsc->quotarealms_count); 33 } 34 35 static inline bool ceph_has_realms_with_quotas(struct inode *inode) 36 { 37 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; 38 return atomic64_read(&mdsc->quotarealms_count) > 0; 39 } 40 41 void ceph_handle_quota(struct ceph_mds_client *mdsc, 42 struct ceph_mds_session *session, 43 struct ceph_msg *msg) 44 { 45 struct super_block *sb = mdsc->fsc->sb; 46 struct ceph_mds_quota *h = msg->front.iov_base; 47 struct ceph_vino vino; 48 struct inode *inode; 49 struct ceph_inode_info *ci; 50 51 if (msg->front.iov_len < sizeof(*h)) { 52 pr_err("%s corrupt message mds%d len %d\n", __func__, 53 session->s_mds, (int)msg->front.iov_len); 54 ceph_msg_dump(msg); 55 return; 56 } 57 58 /* increment msg sequence number */ 59 mutex_lock(&session->s_mutex); 60 session->s_seq++; 61 mutex_unlock(&session->s_mutex); 62 63 /* lookup inode */ 64 vino.ino = le64_to_cpu(h->ino); 65 vino.snap = CEPH_NOSNAP; 66 inode = ceph_find_inode(sb, vino); 67 if (!inode) { 68 pr_warn("Failed to find inode %llu\n", vino.ino); 69 return; 70 } 71 ci = ceph_inode(inode); 72 73 spin_lock(&ci->i_ceph_lock); 74 ci->i_rbytes = le64_to_cpu(h->rbytes); 75 ci->i_rfiles = le64_to_cpu(h->rfiles); 76 ci->i_rsubdirs = le64_to_cpu(h->rsubdirs); 77 __ceph_update_quota(ci, le64_to_cpu(h->max_bytes), 78 le64_to_cpu(h->max_files)); 79 spin_unlock(&ci->i_ceph_lock); 80 81 iput(inode); 82 } 83 84 /* 85 * This function walks through the snaprealm for an inode and returns the 86 * ceph_snap_realm for the first snaprealm that has quotas set (either max_files 87 * or max_bytes). If the root is reached, return the root ceph_snap_realm 88 * instead. 89 * 90 * Note that the caller is responsible for calling ceph_put_snap_realm() on the 91 * returned realm. 92 */ 93 static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc, 94 struct inode *inode) 95 { 96 struct ceph_inode_info *ci = NULL; 97 struct ceph_snap_realm *realm, *next; 98 struct inode *in; 99 bool has_quota; 100 101 if (ceph_snap(inode) != CEPH_NOSNAP) 102 return NULL; 103 104 realm = ceph_inode(inode)->i_snap_realm; 105 if (realm) 106 ceph_get_snap_realm(mdsc, realm); 107 else 108 pr_err_ratelimited("get_quota_realm: ino (%llx.%llx) " 109 "null i_snap_realm\n", ceph_vinop(inode)); 110 while (realm) { 111 spin_lock(&realm->inodes_with_caps_lock); 112 in = realm->inode ? igrab(realm->inode) : NULL; 113 spin_unlock(&realm->inodes_with_caps_lock); 114 if (!in) 115 break; 116 117 ci = ceph_inode(in); 118 has_quota = __ceph_has_any_quota(ci); 119 iput(in); 120 121 next = realm->parent; 122 if (has_quota || !next) 123 return realm; 124 125 ceph_get_snap_realm(mdsc, next); 126 ceph_put_snap_realm(mdsc, realm); 127 realm = next; 128 } 129 if (realm) 130 ceph_put_snap_realm(mdsc, realm); 131 132 return NULL; 133 } 134 135 bool ceph_quota_is_same_realm(struct inode *old, struct inode *new) 136 { 137 struct ceph_mds_client *mdsc = ceph_inode_to_client(old)->mdsc; 138 struct ceph_snap_realm *old_realm, *new_realm; 139 bool is_same; 140 141 down_read(&mdsc->snap_rwsem); 142 old_realm = get_quota_realm(mdsc, old); 143 new_realm = get_quota_realm(mdsc, new); 144 is_same = (old_realm == new_realm); 145 up_read(&mdsc->snap_rwsem); 146 147 if (old_realm) 148 ceph_put_snap_realm(mdsc, old_realm); 149 if (new_realm) 150 ceph_put_snap_realm(mdsc, new_realm); 151 152 return is_same; 153 } 154 155 enum quota_check_op { 156 QUOTA_CHECK_MAX_FILES_OP, /* check quota max_files limit */ 157 QUOTA_CHECK_MAX_BYTES_OP, /* check quota max_files limit */ 158 QUOTA_CHECK_MAX_BYTES_APPROACHING_OP /* check if quota max_files 159 limit is approaching */ 160 }; 161 162 /* 163 * check_quota_exceeded() will walk up the snaprealm hierarchy and, for each 164 * realm, it will execute quota check operation defined by the 'op' parameter. 165 * The snaprealm walk is interrupted if the quota check detects that the quota 166 * is exceeded or if the root inode is reached. 167 */ 168 static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op, 169 loff_t delta) 170 { 171 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; 172 struct ceph_inode_info *ci; 173 struct ceph_snap_realm *realm, *next; 174 struct inode *in; 175 u64 max, rvalue; 176 bool exceeded = false; 177 178 if (ceph_snap(inode) != CEPH_NOSNAP) 179 return false; 180 181 down_read(&mdsc->snap_rwsem); 182 realm = ceph_inode(inode)->i_snap_realm; 183 if (realm) 184 ceph_get_snap_realm(mdsc, realm); 185 else 186 pr_err_ratelimited("check_quota_exceeded: ino (%llx.%llx) " 187 "null i_snap_realm\n", ceph_vinop(inode)); 188 while (realm) { 189 spin_lock(&realm->inodes_with_caps_lock); 190 in = realm->inode ? igrab(realm->inode) : NULL; 191 spin_unlock(&realm->inodes_with_caps_lock); 192 if (!in) 193 break; 194 195 ci = ceph_inode(in); 196 spin_lock(&ci->i_ceph_lock); 197 if (op == QUOTA_CHECK_MAX_FILES_OP) { 198 max = ci->i_max_files; 199 rvalue = ci->i_rfiles + ci->i_rsubdirs; 200 } else { 201 max = ci->i_max_bytes; 202 rvalue = ci->i_rbytes; 203 } 204 spin_unlock(&ci->i_ceph_lock); 205 switch (op) { 206 case QUOTA_CHECK_MAX_FILES_OP: 207 exceeded = (max && (rvalue >= max)); 208 break; 209 case QUOTA_CHECK_MAX_BYTES_OP: 210 exceeded = (max && (rvalue + delta > max)); 211 break; 212 case QUOTA_CHECK_MAX_BYTES_APPROACHING_OP: 213 if (max) { 214 if (rvalue >= max) 215 exceeded = true; 216 else { 217 /* 218 * when we're writing more that 1/16th 219 * of the available space 220 */ 221 exceeded = 222 (((max - rvalue) >> 4) < delta); 223 } 224 } 225 break; 226 default: 227 /* Shouldn't happen */ 228 pr_warn("Invalid quota check op (%d)\n", op); 229 exceeded = true; /* Just break the loop */ 230 } 231 iput(in); 232 233 next = realm->parent; 234 if (exceeded || !next) 235 break; 236 ceph_get_snap_realm(mdsc, next); 237 ceph_put_snap_realm(mdsc, realm); 238 realm = next; 239 } 240 ceph_put_snap_realm(mdsc, realm); 241 up_read(&mdsc->snap_rwsem); 242 243 return exceeded; 244 } 245 246 /* 247 * ceph_quota_is_max_files_exceeded - check if we can create a new file 248 * @inode: directory where a new file is being created 249 * 250 * This functions returns true is max_files quota allows a new file to be 251 * created. It is necessary to walk through the snaprealm hierarchy (until the 252 * FS root) to check all realms with quotas set. 253 */ 254 bool ceph_quota_is_max_files_exceeded(struct inode *inode) 255 { 256 if (!ceph_has_realms_with_quotas(inode)) 257 return false; 258 259 WARN_ON(!S_ISDIR(inode->i_mode)); 260 261 return check_quota_exceeded(inode, QUOTA_CHECK_MAX_FILES_OP, 0); 262 } 263 264 /* 265 * ceph_quota_is_max_bytes_exceeded - check if we can write to a file 266 * @inode: inode being written 267 * @newsize: new size if write succeeds 268 * 269 * This functions returns true is max_bytes quota allows a file size to reach 270 * @newsize; it returns false otherwise. 271 */ 272 bool ceph_quota_is_max_bytes_exceeded(struct inode *inode, loff_t newsize) 273 { 274 loff_t size = i_size_read(inode); 275 276 if (!ceph_has_realms_with_quotas(inode)) 277 return false; 278 279 /* return immediately if we're decreasing file size */ 280 if (newsize <= size) 281 return false; 282 283 return check_quota_exceeded(inode, QUOTA_CHECK_MAX_BYTES_OP, (newsize - size)); 284 } 285 286 /* 287 * ceph_quota_is_max_bytes_approaching - check if we're reaching max_bytes 288 * @inode: inode being written 289 * @newsize: new size if write succeeds 290 * 291 * This function returns true if the new file size @newsize will be consuming 292 * more than 1/16th of the available quota space; it returns false otherwise. 293 */ 294 bool ceph_quota_is_max_bytes_approaching(struct inode *inode, loff_t newsize) 295 { 296 loff_t size = ceph_inode(inode)->i_reported_size; 297 298 if (!ceph_has_realms_with_quotas(inode)) 299 return false; 300 301 /* return immediately if we're decreasing file size */ 302 if (newsize <= size) 303 return false; 304 305 return check_quota_exceeded(inode, QUOTA_CHECK_MAX_BYTES_APPROACHING_OP, 306 (newsize - size)); 307 } 308 309 /* 310 * ceph_quota_update_statfs - if root has quota update statfs with quota status 311 * @fsc: filesystem client instance 312 * @buf: statfs to update 313 * 314 * If the mounted filesystem root has max_bytes quota set, update the filesystem 315 * statistics with the quota status. 316 * 317 * This function returns true if the stats have been updated, false otherwise. 318 */ 319 bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf) 320 { 321 struct ceph_mds_client *mdsc = fsc->mdsc; 322 struct ceph_inode_info *ci; 323 struct ceph_snap_realm *realm; 324 struct inode *in; 325 u64 total = 0, used, free; 326 bool is_updated = false; 327 328 down_read(&mdsc->snap_rwsem); 329 realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root)); 330 up_read(&mdsc->snap_rwsem); 331 if (!realm) 332 return false; 333 334 spin_lock(&realm->inodes_with_caps_lock); 335 in = realm->inode ? igrab(realm->inode) : NULL; 336 spin_unlock(&realm->inodes_with_caps_lock); 337 if (in) { 338 ci = ceph_inode(in); 339 spin_lock(&ci->i_ceph_lock); 340 if (ci->i_max_bytes) { 341 total = ci->i_max_bytes >> CEPH_BLOCK_SHIFT; 342 used = ci->i_rbytes >> CEPH_BLOCK_SHIFT; 343 /* It is possible for a quota to be exceeded. 344 * Report 'zero' in that case 345 */ 346 free = total > used ? total - used : 0; 347 } 348 spin_unlock(&ci->i_ceph_lock); 349 if (total) { 350 buf->f_blocks = total; 351 buf->f_bfree = free; 352 buf->f_bavail = free; 353 is_updated = true; 354 } 355 iput(in); 356 } 357 ceph_put_snap_realm(mdsc, realm); 358 359 return is_updated; 360 } 361 362