1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Ceph cache definitions. 4 * 5 * Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved. 6 * Written by Milosz Tanski (milosz@adfin.com) 7 */ 8 9 #include <linux/ceph/ceph_debug.h> 10 11 #include <linux/fs_context.h> 12 #include "super.h" 13 #include "cache.h" 14 15 struct ceph_aux_inode { 16 u64 version; 17 u64 mtime_sec; 18 u64 mtime_nsec; 19 }; 20 21 struct fscache_netfs ceph_cache_netfs = { 22 .name = "ceph", 23 .version = 0, 24 }; 25 26 static DEFINE_MUTEX(ceph_fscache_lock); 27 static LIST_HEAD(ceph_fscache_list); 28 29 struct ceph_fscache_entry { 30 struct list_head list; 31 struct fscache_cookie *fscache; 32 size_t uniq_len; 33 /* The following members must be last */ 34 struct ceph_fsid fsid; 35 char uniquifier[]; 36 }; 37 38 static const struct fscache_cookie_def ceph_fscache_fsid_object_def = { 39 .name = "CEPH.fsid", 40 .type = FSCACHE_COOKIE_TYPE_INDEX, 41 }; 42 43 int __init ceph_fscache_register(void) 44 { 45 return fscache_register_netfs(&ceph_cache_netfs); 46 } 47 48 void ceph_fscache_unregister(void) 49 { 50 fscache_unregister_netfs(&ceph_cache_netfs); 51 } 52 53 int ceph_fscache_register_fs(struct ceph_fs_client* fsc, struct fs_context *fc) 54 { 55 const struct ceph_fsid *fsid = &fsc->client->fsid; 56 const char *fscache_uniq = fsc->mount_options->fscache_uniq; 57 size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0; 58 struct ceph_fscache_entry *ent; 59 int err = 0; 60 61 mutex_lock(&ceph_fscache_lock); 62 list_for_each_entry(ent, &ceph_fscache_list, list) { 63 if (memcmp(&ent->fsid, fsid, sizeof(*fsid))) 64 continue; 65 if (ent->uniq_len != uniq_len) 66 continue; 67 if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len)) 68 continue; 69 70 errorfc(fc, "fscache cookie already registered for fsid %pU, use fsc=<uniquifier> option", 71 fsid); 72 err = -EBUSY; 73 goto out_unlock; 74 } 75 76 ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL); 77 if (!ent) { 78 err = -ENOMEM; 79 goto out_unlock; 80 } 81 82 memcpy(&ent->fsid, fsid, sizeof(*fsid)); 83 if (uniq_len > 0) { 84 memcpy(&ent->uniquifier, fscache_uniq, uniq_len); 85 ent->uniq_len = uniq_len; 86 } 87 88 fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index, 89 &ceph_fscache_fsid_object_def, 90 &ent->fsid, sizeof(ent->fsid) + uniq_len, 91 NULL, 0, 92 fsc, 0, true); 93 94 if (fsc->fscache) { 95 ent->fscache = fsc->fscache; 96 list_add_tail(&ent->list, &ceph_fscache_list); 97 } else { 98 kfree(ent); 99 errorfc(fc, "unable to register fscache cookie for fsid %pU", 100 fsid); 101 /* all other fs ignore this error */ 102 } 103 out_unlock: 104 mutex_unlock(&ceph_fscache_lock); 105 return err; 106 } 107 108 static enum fscache_checkaux ceph_fscache_inode_check_aux( 109 void *cookie_netfs_data, const void *data, uint16_t dlen, 110 loff_t object_size) 111 { 112 struct ceph_aux_inode aux; 113 struct ceph_inode_info* ci = cookie_netfs_data; 114 struct inode* inode = &ci->vfs_inode; 115 116 if (dlen != sizeof(aux) || 117 i_size_read(inode) != object_size) 118 return FSCACHE_CHECKAUX_OBSOLETE; 119 120 memset(&aux, 0, sizeof(aux)); 121 aux.version = ci->i_version; 122 aux.mtime_sec = inode->i_mtime.tv_sec; 123 aux.mtime_nsec = inode->i_mtime.tv_nsec; 124 125 if (memcmp(data, &aux, sizeof(aux)) != 0) 126 return FSCACHE_CHECKAUX_OBSOLETE; 127 128 dout("ceph inode 0x%p cached okay\n", ci); 129 return FSCACHE_CHECKAUX_OKAY; 130 } 131 132 static const struct fscache_cookie_def ceph_fscache_inode_object_def = { 133 .name = "CEPH.inode", 134 .type = FSCACHE_COOKIE_TYPE_DATAFILE, 135 .check_aux = ceph_fscache_inode_check_aux, 136 }; 137 138 void ceph_fscache_register_inode_cookie(struct inode *inode) 139 { 140 struct ceph_inode_info *ci = ceph_inode(inode); 141 struct ceph_fs_client *fsc = ceph_inode_to_client(inode); 142 struct ceph_aux_inode aux; 143 144 /* No caching for filesystem */ 145 if (!fsc->fscache) 146 return; 147 148 /* Only cache for regular files that are read only */ 149 if (!S_ISREG(inode->i_mode)) 150 return; 151 152 inode_lock_nested(inode, I_MUTEX_CHILD); 153 if (!ci->fscache) { 154 memset(&aux, 0, sizeof(aux)); 155 aux.version = ci->i_version; 156 aux.mtime_sec = inode->i_mtime.tv_sec; 157 aux.mtime_nsec = inode->i_mtime.tv_nsec; 158 ci->fscache = fscache_acquire_cookie(fsc->fscache, 159 &ceph_fscache_inode_object_def, 160 &ci->i_vino, sizeof(ci->i_vino), 161 &aux, sizeof(aux), 162 ci, i_size_read(inode), false); 163 } 164 inode_unlock(inode); 165 } 166 167 void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci) 168 { 169 struct fscache_cookie* cookie; 170 171 if ((cookie = ci->fscache) == NULL) 172 return; 173 174 ci->fscache = NULL; 175 176 fscache_relinquish_cookie(cookie, &ci->i_vino, false); 177 } 178 179 static bool ceph_fscache_can_enable(void *data) 180 { 181 struct inode *inode = data; 182 return !inode_is_open_for_write(inode); 183 } 184 185 void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp) 186 { 187 struct ceph_inode_info *ci = ceph_inode(inode); 188 189 if (!fscache_cookie_valid(ci->fscache)) 190 return; 191 192 if (inode_is_open_for_write(inode)) { 193 dout("fscache_file_set_cookie %p %p disabling cache\n", 194 inode, filp); 195 fscache_disable_cookie(ci->fscache, &ci->i_vino, false); 196 } else { 197 fscache_enable_cookie(ci->fscache, &ci->i_vino, i_size_read(inode), 198 ceph_fscache_can_enable, inode); 199 if (fscache_cookie_enabled(ci->fscache)) { 200 dout("fscache_file_set_cookie %p %p enabling cache\n", 201 inode, filp); 202 } 203 } 204 } 205 206 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc) 207 { 208 if (fscache_cookie_valid(fsc->fscache)) { 209 struct ceph_fscache_entry *ent; 210 bool found = false; 211 212 mutex_lock(&ceph_fscache_lock); 213 list_for_each_entry(ent, &ceph_fscache_list, list) { 214 if (ent->fscache == fsc->fscache) { 215 list_del(&ent->list); 216 kfree(ent); 217 found = true; 218 break; 219 } 220 } 221 WARN_ON_ONCE(!found); 222 mutex_unlock(&ceph_fscache_lock); 223 224 __fscache_relinquish_cookie(fsc->fscache, NULL, false); 225 } 226 fsc->fscache = NULL; 227 } 228