11bd9c4e4SDavid Howells // SPDX-License-Identifier: GPL-2.0-or-later 21bd9c4e4SDavid Howells /* CacheFiles path walking and related routines 31bd9c4e4SDavid Howells * 41bd9c4e4SDavid Howells * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. 51bd9c4e4SDavid Howells * Written by David Howells (dhowells@redhat.com) 61bd9c4e4SDavid Howells */ 71bd9c4e4SDavid Howells 81bd9c4e4SDavid Howells #include <linux/fs.h> 932759f7dSDavid Howells #include <linux/namei.h> 101bd9c4e4SDavid Howells #include "internal.h" 111bd9c4e4SDavid Howells 121bd9c4e4SDavid Howells /* 131bd9c4e4SDavid Howells * Mark the backing file as being a cache file if it's not already in use. The 141bd9c4e4SDavid Howells * mark tells the culling request command that it's not allowed to cull the 151bd9c4e4SDavid Howells * file or directory. The caller must hold the inode lock. 161bd9c4e4SDavid Howells */ 171bd9c4e4SDavid Howells static bool __cachefiles_mark_inode_in_use(struct cachefiles_object *object, 181bd9c4e4SDavid Howells struct dentry *dentry) 191bd9c4e4SDavid Howells { 201bd9c4e4SDavid Howells struct inode *inode = d_backing_inode(dentry); 211bd9c4e4SDavid Howells bool can_use = false; 221bd9c4e4SDavid Howells 231bd9c4e4SDavid Howells if (!(inode->i_flags & S_KERNEL_FILE)) { 241bd9c4e4SDavid Howells inode->i_flags |= S_KERNEL_FILE; 251bd9c4e4SDavid Howells trace_cachefiles_mark_active(object, inode); 261bd9c4e4SDavid Howells can_use = true; 271bd9c4e4SDavid Howells } else { 28b64a3314SDavid Howells trace_cachefiles_mark_failed(object, inode); 29b64a3314SDavid Howells pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n", 30b64a3314SDavid Howells dentry, inode->i_ino); 311bd9c4e4SDavid Howells } 321bd9c4e4SDavid Howells 331bd9c4e4SDavid Howells return can_use; 341bd9c4e4SDavid Howells } 351bd9c4e4SDavid Howells 36169379eaSDavid Howells static bool cachefiles_mark_inode_in_use(struct cachefiles_object *object, 37169379eaSDavid Howells struct dentry *dentry) 38169379eaSDavid Howells { 39169379eaSDavid Howells struct inode *inode = d_backing_inode(dentry); 40169379eaSDavid Howells bool can_use; 41169379eaSDavid Howells 42169379eaSDavid Howells inode_lock(inode); 43169379eaSDavid Howells can_use = __cachefiles_mark_inode_in_use(object, dentry); 44169379eaSDavid Howells inode_unlock(inode); 45169379eaSDavid Howells return can_use; 46169379eaSDavid Howells } 47169379eaSDavid Howells 481bd9c4e4SDavid Howells /* 491bd9c4e4SDavid Howells * Unmark a backing inode. The caller must hold the inode lock. 501bd9c4e4SDavid Howells */ 511bd9c4e4SDavid Howells static void __cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 521bd9c4e4SDavid Howells struct dentry *dentry) 531bd9c4e4SDavid Howells { 541bd9c4e4SDavid Howells struct inode *inode = d_backing_inode(dentry); 551bd9c4e4SDavid Howells 561bd9c4e4SDavid Howells inode->i_flags &= ~S_KERNEL_FILE; 571bd9c4e4SDavid Howells trace_cachefiles_mark_inactive(object, inode); 581bd9c4e4SDavid Howells } 5932759f7dSDavid Howells 60*ea5dc046SJeffle Xu static void cachefiles_do_unmark_inode_in_use(struct cachefiles_object *object, 61*ea5dc046SJeffle Xu struct dentry *dentry) 62*ea5dc046SJeffle Xu { 63*ea5dc046SJeffle Xu struct inode *inode = d_backing_inode(dentry); 64*ea5dc046SJeffle Xu 65*ea5dc046SJeffle Xu inode_lock(inode); 66*ea5dc046SJeffle Xu __cachefiles_unmark_inode_in_use(object, dentry); 67*ea5dc046SJeffle Xu inode_unlock(inode); 68*ea5dc046SJeffle Xu } 69*ea5dc046SJeffle Xu 7032759f7dSDavid Howells /* 71169379eaSDavid Howells * Unmark a backing inode and tell cachefilesd that there's something that can 72169379eaSDavid Howells * be culled. 73169379eaSDavid Howells */ 74169379eaSDavid Howells void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 75169379eaSDavid Howells struct file *file) 76169379eaSDavid Howells { 77169379eaSDavid Howells struct cachefiles_cache *cache = object->volume->cache; 78169379eaSDavid Howells struct inode *inode = file_inode(file); 79169379eaSDavid Howells 80169379eaSDavid Howells if (inode) { 81*ea5dc046SJeffle Xu cachefiles_do_unmark_inode_in_use(object, file->f_path.dentry); 82169379eaSDavid Howells 83169379eaSDavid Howells if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) { 84169379eaSDavid Howells atomic_long_add(inode->i_blocks, &cache->b_released); 85169379eaSDavid Howells if (atomic_inc_return(&cache->f_released)) 86169379eaSDavid Howells cachefiles_state_changed(cache); 87169379eaSDavid Howells } 88169379eaSDavid Howells } 89169379eaSDavid Howells } 90169379eaSDavid Howells 91169379eaSDavid Howells /* 9232759f7dSDavid Howells * get a subdirectory 9332759f7dSDavid Howells */ 9432759f7dSDavid Howells struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 9532759f7dSDavid Howells struct dentry *dir, 9632759f7dSDavid Howells const char *dirname, 9732759f7dSDavid Howells bool *_is_new) 9832759f7dSDavid Howells { 9932759f7dSDavid Howells struct dentry *subdir; 10032759f7dSDavid Howells struct path path; 10132759f7dSDavid Howells int ret; 10232759f7dSDavid Howells 10332759f7dSDavid Howells _enter(",,%s", dirname); 10432759f7dSDavid Howells 10532759f7dSDavid Howells /* search the current directory for the element name */ 10632759f7dSDavid Howells inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); 10732759f7dSDavid Howells 10832759f7dSDavid Howells retry: 10932759f7dSDavid Howells ret = cachefiles_inject_read_error(); 11032759f7dSDavid Howells if (ret == 0) 11132759f7dSDavid Howells subdir = lookup_one_len(dirname, dir, strlen(dirname)); 11232759f7dSDavid Howells else 11332759f7dSDavid Howells subdir = ERR_PTR(ret); 1148c39b8bcSDavid Howells trace_cachefiles_lookup(NULL, dir, subdir); 11532759f7dSDavid Howells if (IS_ERR(subdir)) { 11632759f7dSDavid Howells trace_cachefiles_vfs_error(NULL, d_backing_inode(dir), 11732759f7dSDavid Howells PTR_ERR(subdir), 11832759f7dSDavid Howells cachefiles_trace_lookup_error); 11932759f7dSDavid Howells if (PTR_ERR(subdir) == -ENOMEM) 12032759f7dSDavid Howells goto nomem_d_alloc; 12132759f7dSDavid Howells goto lookup_error; 12232759f7dSDavid Howells } 12332759f7dSDavid Howells 12432759f7dSDavid Howells _debug("subdir -> %pd %s", 12532759f7dSDavid Howells subdir, d_backing_inode(subdir) ? "positive" : "negative"); 12632759f7dSDavid Howells 12732759f7dSDavid Howells /* we need to create the subdir if it doesn't exist yet */ 12832759f7dSDavid Howells if (d_is_negative(subdir)) { 1293929eca7SDavid Howells ret = cachefiles_has_space(cache, 1, 0, 1303929eca7SDavid Howells cachefiles_has_space_for_create); 13132759f7dSDavid Howells if (ret < 0) 13232759f7dSDavid Howells goto mkdir_error; 13332759f7dSDavid Howells 13432759f7dSDavid Howells _debug("attempt mkdir"); 13532759f7dSDavid Howells 13632759f7dSDavid Howells path.mnt = cache->mnt; 13732759f7dSDavid Howells path.dentry = dir; 13832759f7dSDavid Howells ret = security_path_mkdir(&path, subdir, 0700); 13932759f7dSDavid Howells if (ret < 0) 14032759f7dSDavid Howells goto mkdir_error; 14132759f7dSDavid Howells ret = cachefiles_inject_write_error(); 14232759f7dSDavid Howells if (ret == 0) 14332759f7dSDavid Howells ret = vfs_mkdir(&init_user_ns, d_inode(dir), subdir, 0700); 14432759f7dSDavid Howells if (ret < 0) { 14532759f7dSDavid Howells trace_cachefiles_vfs_error(NULL, d_inode(dir), ret, 14632759f7dSDavid Howells cachefiles_trace_mkdir_error); 14732759f7dSDavid Howells goto mkdir_error; 14832759f7dSDavid Howells } 1498c39b8bcSDavid Howells trace_cachefiles_mkdir(dir, subdir); 15032759f7dSDavid Howells 15132759f7dSDavid Howells if (unlikely(d_unhashed(subdir))) { 15232759f7dSDavid Howells cachefiles_put_directory(subdir); 15332759f7dSDavid Howells goto retry; 15432759f7dSDavid Howells } 15532759f7dSDavid Howells ASSERT(d_backing_inode(subdir)); 15632759f7dSDavid Howells 15732759f7dSDavid Howells _debug("mkdir -> %pd{ino=%lu}", 15832759f7dSDavid Howells subdir, d_backing_inode(subdir)->i_ino); 15932759f7dSDavid Howells if (_is_new) 16032759f7dSDavid Howells *_is_new = true; 16132759f7dSDavid Howells } 16232759f7dSDavid Howells 16332759f7dSDavid Howells /* Tell rmdir() it's not allowed to delete the subdir */ 16432759f7dSDavid Howells inode_lock(d_inode(subdir)); 16532759f7dSDavid Howells inode_unlock(d_inode(dir)); 16632759f7dSDavid Howells 16732759f7dSDavid Howells if (!__cachefiles_mark_inode_in_use(NULL, subdir)) 16832759f7dSDavid Howells goto mark_error; 16932759f7dSDavid Howells 17032759f7dSDavid Howells inode_unlock(d_inode(subdir)); 17132759f7dSDavid Howells 17232759f7dSDavid Howells /* we need to make sure the subdir is a directory */ 17332759f7dSDavid Howells ASSERT(d_backing_inode(subdir)); 17432759f7dSDavid Howells 17532759f7dSDavid Howells if (!d_can_lookup(subdir)) { 17632759f7dSDavid Howells pr_err("%s is not a directory\n", dirname); 17732759f7dSDavid Howells ret = -EIO; 17832759f7dSDavid Howells goto check_error; 17932759f7dSDavid Howells } 18032759f7dSDavid Howells 18132759f7dSDavid Howells ret = -EPERM; 18232759f7dSDavid Howells if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) || 18332759f7dSDavid Howells !d_backing_inode(subdir)->i_op->lookup || 18432759f7dSDavid Howells !d_backing_inode(subdir)->i_op->mkdir || 18532759f7dSDavid Howells !d_backing_inode(subdir)->i_op->rename || 18632759f7dSDavid Howells !d_backing_inode(subdir)->i_op->rmdir || 18732759f7dSDavid Howells !d_backing_inode(subdir)->i_op->unlink) 18832759f7dSDavid Howells goto check_error; 18932759f7dSDavid Howells 19032759f7dSDavid Howells _leave(" = [%lu]", d_backing_inode(subdir)->i_ino); 19132759f7dSDavid Howells return subdir; 19232759f7dSDavid Howells 19332759f7dSDavid Howells check_error: 19432759f7dSDavid Howells cachefiles_put_directory(subdir); 19532759f7dSDavid Howells _leave(" = %d [check]", ret); 19632759f7dSDavid Howells return ERR_PTR(ret); 19732759f7dSDavid Howells 19832759f7dSDavid Howells mark_error: 19932759f7dSDavid Howells inode_unlock(d_inode(subdir)); 20032759f7dSDavid Howells dput(subdir); 20132759f7dSDavid Howells return ERR_PTR(-EBUSY); 20232759f7dSDavid Howells 20332759f7dSDavid Howells mkdir_error: 20432759f7dSDavid Howells inode_unlock(d_inode(dir)); 20532759f7dSDavid Howells dput(subdir); 20632759f7dSDavid Howells pr_err("mkdir %s failed with error %d\n", dirname, ret); 20732759f7dSDavid Howells return ERR_PTR(ret); 20832759f7dSDavid Howells 20932759f7dSDavid Howells lookup_error: 21032759f7dSDavid Howells inode_unlock(d_inode(dir)); 21132759f7dSDavid Howells ret = PTR_ERR(subdir); 21232759f7dSDavid Howells pr_err("Lookup %s failed with error %d\n", dirname, ret); 21332759f7dSDavid Howells return ERR_PTR(ret); 21432759f7dSDavid Howells 21532759f7dSDavid Howells nomem_d_alloc: 21632759f7dSDavid Howells inode_unlock(d_inode(dir)); 21732759f7dSDavid Howells _leave(" = -ENOMEM"); 21832759f7dSDavid Howells return ERR_PTR(-ENOMEM); 21932759f7dSDavid Howells } 22032759f7dSDavid Howells 22132759f7dSDavid Howells /* 22232759f7dSDavid Howells * Put a subdirectory. 22332759f7dSDavid Howells */ 22432759f7dSDavid Howells void cachefiles_put_directory(struct dentry *dir) 22532759f7dSDavid Howells { 22632759f7dSDavid Howells if (dir) { 22732759f7dSDavid Howells inode_lock(dir->d_inode); 22832759f7dSDavid Howells __cachefiles_unmark_inode_in_use(NULL, dir); 22932759f7dSDavid Howells inode_unlock(dir->d_inode); 23032759f7dSDavid Howells dput(dir); 23132759f7dSDavid Howells } 23232759f7dSDavid Howells } 23307a90e97SDavid Howells 23407a90e97SDavid Howells /* 23507a90e97SDavid Howells * Remove a regular file from the cache. 23607a90e97SDavid Howells */ 23707a90e97SDavid Howells static int cachefiles_unlink(struct cachefiles_cache *cache, 23807a90e97SDavid Howells struct cachefiles_object *object, 23907a90e97SDavid Howells struct dentry *dir, struct dentry *dentry, 24007a90e97SDavid Howells enum fscache_why_object_killed why) 24107a90e97SDavid Howells { 24207a90e97SDavid Howells struct path path = { 24307a90e97SDavid Howells .mnt = cache->mnt, 24407a90e97SDavid Howells .dentry = dir, 24507a90e97SDavid Howells }; 24607a90e97SDavid Howells int ret; 24707a90e97SDavid Howells 2488c39b8bcSDavid Howells trace_cachefiles_unlink(object, d_inode(dentry)->i_ino, why); 24907a90e97SDavid Howells ret = security_path_unlink(&path, dentry); 25007a90e97SDavid Howells if (ret < 0) { 25107a90e97SDavid Howells cachefiles_io_error(cache, "Unlink security error"); 25207a90e97SDavid Howells return ret; 25307a90e97SDavid Howells } 25407a90e97SDavid Howells 25507a90e97SDavid Howells ret = cachefiles_inject_remove_error(); 25607a90e97SDavid Howells if (ret == 0) { 25707a90e97SDavid Howells ret = vfs_unlink(&init_user_ns, d_backing_inode(dir), dentry, NULL); 25807a90e97SDavid Howells if (ret == -EIO) 25907a90e97SDavid Howells cachefiles_io_error(cache, "Unlink failed"); 26007a90e97SDavid Howells } 26107a90e97SDavid Howells if (ret != 0) 26207a90e97SDavid Howells trace_cachefiles_vfs_error(object, d_backing_inode(dir), ret, 26307a90e97SDavid Howells cachefiles_trace_unlink_error); 26407a90e97SDavid Howells return ret; 26507a90e97SDavid Howells } 26607a90e97SDavid Howells 26707a90e97SDavid Howells /* 26807a90e97SDavid Howells * Delete an object representation from the cache 26907a90e97SDavid Howells * - File backed objects are unlinked 27007a90e97SDavid Howells * - Directory backed objects are stuffed into the graveyard for userspace to 27107a90e97SDavid Howells * delete 27207a90e97SDavid Howells */ 27307a90e97SDavid Howells int cachefiles_bury_object(struct cachefiles_cache *cache, 27407a90e97SDavid Howells struct cachefiles_object *object, 27507a90e97SDavid Howells struct dentry *dir, 27607a90e97SDavid Howells struct dentry *rep, 27707a90e97SDavid Howells enum fscache_why_object_killed why) 27807a90e97SDavid Howells { 27907a90e97SDavid Howells struct dentry *grave, *trap; 28007a90e97SDavid Howells struct path path, path_to_graveyard; 28107a90e97SDavid Howells char nbuffer[8 + 8 + 1]; 28207a90e97SDavid Howells int ret; 28307a90e97SDavid Howells 28407a90e97SDavid Howells _enter(",'%pd','%pd'", dir, rep); 28507a90e97SDavid Howells 28607a90e97SDavid Howells if (rep->d_parent != dir) { 28707a90e97SDavid Howells inode_unlock(d_inode(dir)); 28807a90e97SDavid Howells _leave(" = -ESTALE"); 28907a90e97SDavid Howells return -ESTALE; 29007a90e97SDavid Howells } 29107a90e97SDavid Howells 29207a90e97SDavid Howells /* non-directories can just be unlinked */ 29307a90e97SDavid Howells if (!d_is_dir(rep)) { 29407a90e97SDavid Howells dget(rep); /* Stop the dentry being negated if it's only pinned 29507a90e97SDavid Howells * by a file struct. 29607a90e97SDavid Howells */ 29707a90e97SDavid Howells ret = cachefiles_unlink(cache, object, dir, rep, why); 29807a90e97SDavid Howells dput(rep); 29907a90e97SDavid Howells 30007a90e97SDavid Howells inode_unlock(d_inode(dir)); 30107a90e97SDavid Howells _leave(" = %d", ret); 30207a90e97SDavid Howells return ret; 30307a90e97SDavid Howells } 30407a90e97SDavid Howells 30507a90e97SDavid Howells /* directories have to be moved to the graveyard */ 30607a90e97SDavid Howells _debug("move stale object to graveyard"); 30707a90e97SDavid Howells inode_unlock(d_inode(dir)); 30807a90e97SDavid Howells 30907a90e97SDavid Howells try_again: 31007a90e97SDavid Howells /* first step is to make up a grave dentry in the graveyard */ 31107a90e97SDavid Howells sprintf(nbuffer, "%08x%08x", 31207a90e97SDavid Howells (uint32_t) ktime_get_real_seconds(), 31307a90e97SDavid Howells (uint32_t) atomic_inc_return(&cache->gravecounter)); 31407a90e97SDavid Howells 31507a90e97SDavid Howells /* do the multiway lock magic */ 31607a90e97SDavid Howells trap = lock_rename(cache->graveyard, dir); 31707a90e97SDavid Howells 31807a90e97SDavid Howells /* do some checks before getting the grave dentry */ 31907a90e97SDavid Howells if (rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) { 32007a90e97SDavid Howells /* the entry was probably culled when we dropped the parent dir 32107a90e97SDavid Howells * lock */ 32207a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 32307a90e97SDavid Howells _leave(" = 0 [culled?]"); 32407a90e97SDavid Howells return 0; 32507a90e97SDavid Howells } 32607a90e97SDavid Howells 32707a90e97SDavid Howells if (!d_can_lookup(cache->graveyard)) { 32807a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 32907a90e97SDavid Howells cachefiles_io_error(cache, "Graveyard no longer a directory"); 33007a90e97SDavid Howells return -EIO; 33107a90e97SDavid Howells } 33207a90e97SDavid Howells 33307a90e97SDavid Howells if (trap == rep) { 33407a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 33507a90e97SDavid Howells cachefiles_io_error(cache, "May not make directory loop"); 33607a90e97SDavid Howells return -EIO; 33707a90e97SDavid Howells } 33807a90e97SDavid Howells 33907a90e97SDavid Howells if (d_mountpoint(rep)) { 34007a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 34107a90e97SDavid Howells cachefiles_io_error(cache, "Mountpoint in cache"); 34207a90e97SDavid Howells return -EIO; 34307a90e97SDavid Howells } 34407a90e97SDavid Howells 34507a90e97SDavid Howells grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer)); 34607a90e97SDavid Howells if (IS_ERR(grave)) { 34707a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 34807a90e97SDavid Howells trace_cachefiles_vfs_error(object, d_inode(cache->graveyard), 34907a90e97SDavid Howells PTR_ERR(grave), 35007a90e97SDavid Howells cachefiles_trace_lookup_error); 35107a90e97SDavid Howells 35207a90e97SDavid Howells if (PTR_ERR(grave) == -ENOMEM) { 35307a90e97SDavid Howells _leave(" = -ENOMEM"); 35407a90e97SDavid Howells return -ENOMEM; 35507a90e97SDavid Howells } 35607a90e97SDavid Howells 35707a90e97SDavid Howells cachefiles_io_error(cache, "Lookup error %ld", PTR_ERR(grave)); 35807a90e97SDavid Howells return -EIO; 35907a90e97SDavid Howells } 36007a90e97SDavid Howells 36107a90e97SDavid Howells if (d_is_positive(grave)) { 36207a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 36307a90e97SDavid Howells dput(grave); 36407a90e97SDavid Howells grave = NULL; 36507a90e97SDavid Howells cond_resched(); 36607a90e97SDavid Howells goto try_again; 36707a90e97SDavid Howells } 36807a90e97SDavid Howells 36907a90e97SDavid Howells if (d_mountpoint(grave)) { 37007a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 37107a90e97SDavid Howells dput(grave); 37207a90e97SDavid Howells cachefiles_io_error(cache, "Mountpoint in graveyard"); 37307a90e97SDavid Howells return -EIO; 37407a90e97SDavid Howells } 37507a90e97SDavid Howells 37607a90e97SDavid Howells /* target should not be an ancestor of source */ 37707a90e97SDavid Howells if (trap == grave) { 37807a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 37907a90e97SDavid Howells dput(grave); 38007a90e97SDavid Howells cachefiles_io_error(cache, "May not make directory loop"); 38107a90e97SDavid Howells return -EIO; 38207a90e97SDavid Howells } 38307a90e97SDavid Howells 38407a90e97SDavid Howells /* attempt the rename */ 38507a90e97SDavid Howells path.mnt = cache->mnt; 38607a90e97SDavid Howells path.dentry = dir; 38707a90e97SDavid Howells path_to_graveyard.mnt = cache->mnt; 38807a90e97SDavid Howells path_to_graveyard.dentry = cache->graveyard; 38907a90e97SDavid Howells ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0); 39007a90e97SDavid Howells if (ret < 0) { 39107a90e97SDavid Howells cachefiles_io_error(cache, "Rename security error %d", ret); 39207a90e97SDavid Howells } else { 39307a90e97SDavid Howells struct renamedata rd = { 39407a90e97SDavid Howells .old_mnt_userns = &init_user_ns, 39507a90e97SDavid Howells .old_dir = d_inode(dir), 39607a90e97SDavid Howells .old_dentry = rep, 39707a90e97SDavid Howells .new_mnt_userns = &init_user_ns, 39807a90e97SDavid Howells .new_dir = d_inode(cache->graveyard), 39907a90e97SDavid Howells .new_dentry = grave, 40007a90e97SDavid Howells }; 4018c39b8bcSDavid Howells trace_cachefiles_rename(object, d_inode(rep)->i_ino, why); 40207a90e97SDavid Howells ret = cachefiles_inject_read_error(); 40307a90e97SDavid Howells if (ret == 0) 40407a90e97SDavid Howells ret = vfs_rename(&rd); 40507a90e97SDavid Howells if (ret != 0) 40607a90e97SDavid Howells trace_cachefiles_vfs_error(object, d_inode(dir), ret, 40707a90e97SDavid Howells cachefiles_trace_rename_error); 40807a90e97SDavid Howells if (ret != 0 && ret != -ENOMEM) 40907a90e97SDavid Howells cachefiles_io_error(cache, 41007a90e97SDavid Howells "Rename failed with error %d", ret); 41107a90e97SDavid Howells } 41207a90e97SDavid Howells 41307a90e97SDavid Howells __cachefiles_unmark_inode_in_use(object, rep); 41407a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 41507a90e97SDavid Howells dput(grave); 41607a90e97SDavid Howells _leave(" = 0"); 41707a90e97SDavid Howells return 0; 41807a90e97SDavid Howells } 41907a90e97SDavid Howells 42007a90e97SDavid Howells /* 4211f08c925SDavid Howells * Delete a cache file. 4221f08c925SDavid Howells */ 4231f08c925SDavid Howells int cachefiles_delete_object(struct cachefiles_object *object, 4241f08c925SDavid Howells enum fscache_why_object_killed why) 4251f08c925SDavid Howells { 4261f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 4271f08c925SDavid Howells struct dentry *dentry = object->file->f_path.dentry; 4281f08c925SDavid Howells struct dentry *fan = volume->fanout[(u8)object->cookie->key_hash]; 4291f08c925SDavid Howells int ret; 4301f08c925SDavid Howells 4311f08c925SDavid Howells _enter(",OBJ%x{%pD}", object->debug_id, object->file); 4321f08c925SDavid Howells 4331f08c925SDavid Howells /* Stop the dentry being negated if it's only pinned by a file struct. */ 4341f08c925SDavid Howells dget(dentry); 4351f08c925SDavid Howells 4361f08c925SDavid Howells inode_lock_nested(d_backing_inode(fan), I_MUTEX_PARENT); 4371f08c925SDavid Howells ret = cachefiles_unlink(volume->cache, object, fan, dentry, why); 4381f08c925SDavid Howells inode_unlock(d_backing_inode(fan)); 4391f08c925SDavid Howells dput(dentry); 4401f08c925SDavid Howells return ret; 4411f08c925SDavid Howells } 4421f08c925SDavid Howells 4431f08c925SDavid Howells /* 4441f08c925SDavid Howells * Create a temporary file and leave it unattached and un-xattr'd until the 4451f08c925SDavid Howells * time comes to discard the object from memory. 4461f08c925SDavid Howells */ 4471f08c925SDavid Howells struct file *cachefiles_create_tmpfile(struct cachefiles_object *object) 4481f08c925SDavid Howells { 4491f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 4501f08c925SDavid Howells struct cachefiles_cache *cache = volume->cache; 4511f08c925SDavid Howells const struct cred *saved_cred; 4521f08c925SDavid Howells struct dentry *fan = volume->fanout[(u8)object->cookie->key_hash]; 4531f08c925SDavid Howells struct file *file; 4541f08c925SDavid Howells struct path path; 4551f08c925SDavid Howells uint64_t ni_size = object->cookie->object_size; 4561f08c925SDavid Howells long ret; 4571f08c925SDavid Howells 4581f08c925SDavid Howells ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE); 4591f08c925SDavid Howells 4601f08c925SDavid Howells cachefiles_begin_secure(cache, &saved_cred); 4611f08c925SDavid Howells 4621f08c925SDavid Howells path.mnt = cache->mnt; 4631f08c925SDavid Howells ret = cachefiles_inject_write_error(); 4641f08c925SDavid Howells if (ret == 0) 4651f08c925SDavid Howells path.dentry = vfs_tmpfile(&init_user_ns, fan, S_IFREG, O_RDWR); 4661f08c925SDavid Howells else 4671f08c925SDavid Howells path.dentry = ERR_PTR(ret); 4681f08c925SDavid Howells if (IS_ERR(path.dentry)) { 4691f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(path.dentry), 4701f08c925SDavid Howells cachefiles_trace_tmpfile_error); 4711f08c925SDavid Howells if (PTR_ERR(path.dentry) == -EIO) 4721f08c925SDavid Howells cachefiles_io_error_obj(object, "Failed to create tmpfile"); 4731f08c925SDavid Howells file = ERR_CAST(path.dentry); 4741f08c925SDavid Howells goto out; 4751f08c925SDavid Howells } 4761f08c925SDavid Howells 4771f08c925SDavid Howells trace_cachefiles_tmpfile(object, d_backing_inode(path.dentry)); 4781f08c925SDavid Howells 4791f08c925SDavid Howells if (!cachefiles_mark_inode_in_use(object, path.dentry)) { 4801f08c925SDavid Howells file = ERR_PTR(-EBUSY); 4811f08c925SDavid Howells goto out_dput; 4821f08c925SDavid Howells } 4831f08c925SDavid Howells 4841f08c925SDavid Howells if (ni_size > 0) { 4851f08c925SDavid Howells trace_cachefiles_trunc(object, d_backing_inode(path.dentry), 0, ni_size, 4861f08c925SDavid Howells cachefiles_trunc_expand_tmpfile); 4871f08c925SDavid Howells ret = cachefiles_inject_write_error(); 4881f08c925SDavid Howells if (ret == 0) 4891f08c925SDavid Howells ret = vfs_truncate(&path, ni_size); 4901f08c925SDavid Howells if (ret < 0) { 4911f08c925SDavid Howells trace_cachefiles_vfs_error( 4921f08c925SDavid Howells object, d_backing_inode(path.dentry), ret, 4931f08c925SDavid Howells cachefiles_trace_trunc_error); 4941f08c925SDavid Howells file = ERR_PTR(ret); 495*ea5dc046SJeffle Xu goto out_unuse; 4961f08c925SDavid Howells } 4971f08c925SDavid Howells } 4981f08c925SDavid Howells 4991f08c925SDavid Howells file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT, 5001f08c925SDavid Howells d_backing_inode(path.dentry), cache->cache_cred); 5011f08c925SDavid Howells if (IS_ERR(file)) { 5021f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_backing_inode(path.dentry), 5031f08c925SDavid Howells PTR_ERR(file), 5041f08c925SDavid Howells cachefiles_trace_open_error); 505*ea5dc046SJeffle Xu goto out_unuse; 5061f08c925SDavid Howells } 5071f08c925SDavid Howells if (unlikely(!file->f_op->read_iter) || 5081f08c925SDavid Howells unlikely(!file->f_op->write_iter)) { 5091f08c925SDavid Howells fput(file); 5101f08c925SDavid Howells pr_notice("Cache does not support read_iter and write_iter\n"); 5111f08c925SDavid Howells file = ERR_PTR(-EINVAL); 512*ea5dc046SJeffle Xu goto out_unuse; 5131f08c925SDavid Howells } 5141f08c925SDavid Howells 515*ea5dc046SJeffle Xu goto out_dput; 516*ea5dc046SJeffle Xu 517*ea5dc046SJeffle Xu out_unuse: 518*ea5dc046SJeffle Xu cachefiles_do_unmark_inode_in_use(object, path.dentry); 5191f08c925SDavid Howells out_dput: 5201f08c925SDavid Howells dput(path.dentry); 5211f08c925SDavid Howells out: 5221f08c925SDavid Howells cachefiles_end_secure(cache, saved_cred); 5231f08c925SDavid Howells return file; 5241f08c925SDavid Howells } 5251f08c925SDavid Howells 5261f08c925SDavid Howells /* 5271f08c925SDavid Howells * Create a new file. 5281f08c925SDavid Howells */ 5291f08c925SDavid Howells static bool cachefiles_create_file(struct cachefiles_object *object) 5301f08c925SDavid Howells { 5311f08c925SDavid Howells struct file *file; 5321f08c925SDavid Howells int ret; 5331f08c925SDavid Howells 5343929eca7SDavid Howells ret = cachefiles_has_space(object->volume->cache, 1, 0, 5353929eca7SDavid Howells cachefiles_has_space_for_create); 5361f08c925SDavid Howells if (ret < 0) 5371f08c925SDavid Howells return false; 5381f08c925SDavid Howells 5391f08c925SDavid Howells file = cachefiles_create_tmpfile(object); 5401f08c925SDavid Howells if (IS_ERR(file)) 5411f08c925SDavid Howells return false; 5421f08c925SDavid Howells 5431f08c925SDavid Howells set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags); 5441f08c925SDavid Howells set_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags); 5451f08c925SDavid Howells _debug("create -> %pD{ino=%lu}", file, file_inode(file)->i_ino); 5461f08c925SDavid Howells object->file = file; 5471f08c925SDavid Howells return true; 5481f08c925SDavid Howells } 5491f08c925SDavid Howells 5501f08c925SDavid Howells /* 5511f08c925SDavid Howells * Open an existing file, checking its attributes and replacing it if it is 5521f08c925SDavid Howells * stale. 5531f08c925SDavid Howells */ 5541f08c925SDavid Howells static bool cachefiles_open_file(struct cachefiles_object *object, 5551f08c925SDavid Howells struct dentry *dentry) 5561f08c925SDavid Howells { 5571f08c925SDavid Howells struct cachefiles_cache *cache = object->volume->cache; 5581f08c925SDavid Howells struct file *file; 5591f08c925SDavid Howells struct path path; 5601f08c925SDavid Howells int ret; 5611f08c925SDavid Howells 5621f08c925SDavid Howells _enter("%pd", dentry); 5631f08c925SDavid Howells 5641f08c925SDavid Howells if (!cachefiles_mark_inode_in_use(object, dentry)) 5651f08c925SDavid Howells return false; 5661f08c925SDavid Howells 5671f08c925SDavid Howells /* We need to open a file interface onto a data file now as we can't do 5681f08c925SDavid Howells * it on demand because writeback called from do_exit() sees 5691f08c925SDavid Howells * current->fs == NULL - which breaks d_path() called from ext4 open. 5701f08c925SDavid Howells */ 5711f08c925SDavid Howells path.mnt = cache->mnt; 5721f08c925SDavid Howells path.dentry = dentry; 5731f08c925SDavid Howells file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT, 5741f08c925SDavid Howells d_backing_inode(dentry), cache->cache_cred); 5751f08c925SDavid Howells if (IS_ERR(file)) { 5761f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_backing_inode(dentry), 5771f08c925SDavid Howells PTR_ERR(file), 5781f08c925SDavid Howells cachefiles_trace_open_error); 5791f08c925SDavid Howells goto error; 5801f08c925SDavid Howells } 5811f08c925SDavid Howells 5821f08c925SDavid Howells if (unlikely(!file->f_op->read_iter) || 5831f08c925SDavid Howells unlikely(!file->f_op->write_iter)) { 5841f08c925SDavid Howells pr_notice("Cache does not support read_iter and write_iter\n"); 5851f08c925SDavid Howells goto error_fput; 5861f08c925SDavid Howells } 5871f08c925SDavid Howells _debug("file -> %pd positive", dentry); 5881f08c925SDavid Howells 5891f08c925SDavid Howells ret = cachefiles_check_auxdata(object, file); 5901f08c925SDavid Howells if (ret < 0) 5911f08c925SDavid Howells goto check_failed; 5921f08c925SDavid Howells 5931f08c925SDavid Howells object->file = file; 5941f08c925SDavid Howells 5951f08c925SDavid Howells /* Always update the atime on an object we've just looked up (this is 5961f08c925SDavid Howells * used to keep track of culling, and atimes are only updated by read, 5971f08c925SDavid Howells * write and readdir but not lookup or open). 5981f08c925SDavid Howells */ 5991f08c925SDavid Howells touch_atime(&file->f_path); 6001f08c925SDavid Howells dput(dentry); 6011f08c925SDavid Howells return true; 6021f08c925SDavid Howells 6031f08c925SDavid Howells check_failed: 6041f08c925SDavid Howells fscache_cookie_lookup_negative(object->cookie); 6051f08c925SDavid Howells cachefiles_unmark_inode_in_use(object, file); 6061f08c925SDavid Howells fput(file); 6071f08c925SDavid Howells dput(dentry); 608*ea5dc046SJeffle Xu if (ret == -ESTALE) 6091f08c925SDavid Howells return cachefiles_create_file(object); 610*ea5dc046SJeffle Xu return false; 611*ea5dc046SJeffle Xu 6121f08c925SDavid Howells error_fput: 6131f08c925SDavid Howells fput(file); 6141f08c925SDavid Howells error: 615*ea5dc046SJeffle Xu cachefiles_do_unmark_inode_in_use(object, dentry); 6161f08c925SDavid Howells dput(dentry); 6171f08c925SDavid Howells return false; 6181f08c925SDavid Howells } 6191f08c925SDavid Howells 6201f08c925SDavid Howells /* 6211f08c925SDavid Howells * walk from the parent object to the child object through the backing 6221f08c925SDavid Howells * filesystem, creating directories as we go 6231f08c925SDavid Howells */ 6241f08c925SDavid Howells bool cachefiles_look_up_object(struct cachefiles_object *object) 6251f08c925SDavid Howells { 6261f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 6271f08c925SDavid Howells struct dentry *dentry, *fan = volume->fanout[(u8)object->cookie->key_hash]; 6281f08c925SDavid Howells int ret; 6291f08c925SDavid Howells 6301f08c925SDavid Howells _enter("OBJ%x,%s,", object->debug_id, object->d_name); 6311f08c925SDavid Howells 6321f08c925SDavid Howells /* Look up path "cache/vol/fanout/file". */ 6331f08c925SDavid Howells ret = cachefiles_inject_read_error(); 6341f08c925SDavid Howells if (ret == 0) 6351f08c925SDavid Howells dentry = lookup_positive_unlocked(object->d_name, fan, 6361f08c925SDavid Howells object->d_name_len); 6371f08c925SDavid Howells else 6381f08c925SDavid Howells dentry = ERR_PTR(ret); 6398c39b8bcSDavid Howells trace_cachefiles_lookup(object, fan, dentry); 6401f08c925SDavid Howells if (IS_ERR(dentry)) { 6411f08c925SDavid Howells if (dentry == ERR_PTR(-ENOENT)) 6421f08c925SDavid Howells goto new_file; 6431f08c925SDavid Howells if (dentry == ERR_PTR(-EIO)) 6441f08c925SDavid Howells cachefiles_io_error_obj(object, "Lookup failed"); 6451f08c925SDavid Howells return false; 6461f08c925SDavid Howells } 6471f08c925SDavid Howells 6481f08c925SDavid Howells if (!d_is_reg(dentry)) { 6491f08c925SDavid Howells pr_err("%pd is not a file\n", dentry); 6501f08c925SDavid Howells inode_lock_nested(d_inode(fan), I_MUTEX_PARENT); 6511f08c925SDavid Howells ret = cachefiles_bury_object(volume->cache, object, fan, dentry, 6521f08c925SDavid Howells FSCACHE_OBJECT_IS_WEIRD); 6531f08c925SDavid Howells dput(dentry); 6541f08c925SDavid Howells if (ret < 0) 6551f08c925SDavid Howells return false; 6561f08c925SDavid Howells goto new_file; 6571f08c925SDavid Howells } 6581f08c925SDavid Howells 6591f08c925SDavid Howells if (!cachefiles_open_file(object, dentry)) 6601f08c925SDavid Howells return false; 6611f08c925SDavid Howells 6621f08c925SDavid Howells _leave(" = t [%lu]", file_inode(object->file)->i_ino); 6631f08c925SDavid Howells return true; 6641f08c925SDavid Howells 6651f08c925SDavid Howells new_file: 6661f08c925SDavid Howells fscache_cookie_lookup_negative(object->cookie); 6671f08c925SDavid Howells return cachefiles_create_file(object); 6681f08c925SDavid Howells } 6691f08c925SDavid Howells 6701f08c925SDavid Howells /* 6711f08c925SDavid Howells * Attempt to link a temporary file into its rightful place in the cache. 6721f08c925SDavid Howells */ 6731f08c925SDavid Howells bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, 6741f08c925SDavid Howells struct cachefiles_object *object) 6751f08c925SDavid Howells { 6761f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 6771f08c925SDavid Howells struct dentry *dentry, *fan = volume->fanout[(u8)object->cookie->key_hash]; 6781f08c925SDavid Howells bool success = false; 6791f08c925SDavid Howells int ret; 6801f08c925SDavid Howells 6811f08c925SDavid Howells _enter(",%pD", object->file); 6821f08c925SDavid Howells 6831f08c925SDavid Howells inode_lock_nested(d_inode(fan), I_MUTEX_PARENT); 6841f08c925SDavid Howells ret = cachefiles_inject_read_error(); 6851f08c925SDavid Howells if (ret == 0) 6861f08c925SDavid Howells dentry = lookup_one_len(object->d_name, fan, object->d_name_len); 6871f08c925SDavid Howells else 6881f08c925SDavid Howells dentry = ERR_PTR(ret); 6891f08c925SDavid Howells if (IS_ERR(dentry)) { 6901f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry), 6911f08c925SDavid Howells cachefiles_trace_lookup_error); 6921f08c925SDavid Howells _debug("lookup fail %ld", PTR_ERR(dentry)); 6931f08c925SDavid Howells goto out_unlock; 6941f08c925SDavid Howells } 6951f08c925SDavid Howells 6961f08c925SDavid Howells if (!d_is_negative(dentry)) { 6971f08c925SDavid Howells if (d_backing_inode(dentry) == file_inode(object->file)) { 6981f08c925SDavid Howells success = true; 6991f08c925SDavid Howells goto out_dput; 7001f08c925SDavid Howells } 7011f08c925SDavid Howells 7021f08c925SDavid Howells ret = cachefiles_unlink(volume->cache, object, fan, dentry, 7031f08c925SDavid Howells FSCACHE_OBJECT_IS_STALE); 7041f08c925SDavid Howells if (ret < 0) 7051f08c925SDavid Howells goto out_dput; 7061f08c925SDavid Howells 7071f08c925SDavid Howells dput(dentry); 7081f08c925SDavid Howells ret = cachefiles_inject_read_error(); 7091f08c925SDavid Howells if (ret == 0) 7101f08c925SDavid Howells dentry = lookup_one_len(object->d_name, fan, object->d_name_len); 7111f08c925SDavid Howells else 7121f08c925SDavid Howells dentry = ERR_PTR(ret); 7131f08c925SDavid Howells if (IS_ERR(dentry)) { 7141f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry), 7151f08c925SDavid Howells cachefiles_trace_lookup_error); 7161f08c925SDavid Howells _debug("lookup fail %ld", PTR_ERR(dentry)); 7171f08c925SDavid Howells goto out_unlock; 7181f08c925SDavid Howells } 7191f08c925SDavid Howells } 7201f08c925SDavid Howells 7211f08c925SDavid Howells ret = cachefiles_inject_read_error(); 7221f08c925SDavid Howells if (ret == 0) 7231f08c925SDavid Howells ret = vfs_link(object->file->f_path.dentry, &init_user_ns, 7241f08c925SDavid Howells d_inode(fan), dentry, NULL); 7251f08c925SDavid Howells if (ret < 0) { 7261f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_inode(fan), ret, 7271f08c925SDavid Howells cachefiles_trace_link_error); 7281f08c925SDavid Howells _debug("link fail %d", ret); 7291f08c925SDavid Howells } else { 7301f08c925SDavid Howells trace_cachefiles_link(object, file_inode(object->file)); 7311f08c925SDavid Howells spin_lock(&object->lock); 7321f08c925SDavid Howells /* TODO: Do we want to switch the file pointer to the new dentry? */ 7331f08c925SDavid Howells clear_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags); 7341f08c925SDavid Howells spin_unlock(&object->lock); 7351f08c925SDavid Howells success = true; 7361f08c925SDavid Howells } 7371f08c925SDavid Howells 7381f08c925SDavid Howells out_dput: 7391f08c925SDavid Howells dput(dentry); 7401f08c925SDavid Howells out_unlock: 7411f08c925SDavid Howells inode_unlock(d_inode(fan)); 7421f08c925SDavid Howells _leave(" = %u", success); 7431f08c925SDavid Howells return success; 7441f08c925SDavid Howells } 7451f08c925SDavid Howells 7461f08c925SDavid Howells /* 74707a90e97SDavid Howells * Look up an inode to be checked or culled. Return -EBUSY if the inode is 74807a90e97SDavid Howells * marked in use. 74907a90e97SDavid Howells */ 75007a90e97SDavid Howells static struct dentry *cachefiles_lookup_for_cull(struct cachefiles_cache *cache, 75107a90e97SDavid Howells struct dentry *dir, 75207a90e97SDavid Howells char *filename) 75307a90e97SDavid Howells { 75407a90e97SDavid Howells struct dentry *victim; 75507a90e97SDavid Howells int ret = -ENOENT; 75607a90e97SDavid Howells 75707a90e97SDavid Howells inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); 75807a90e97SDavid Howells 75907a90e97SDavid Howells victim = lookup_one_len(filename, dir, strlen(filename)); 76007a90e97SDavid Howells if (IS_ERR(victim)) 76107a90e97SDavid Howells goto lookup_error; 76207a90e97SDavid Howells if (d_is_negative(victim)) 76307a90e97SDavid Howells goto lookup_put; 76407a90e97SDavid Howells if (d_inode(victim)->i_flags & S_KERNEL_FILE) 76507a90e97SDavid Howells goto lookup_busy; 76607a90e97SDavid Howells return victim; 76707a90e97SDavid Howells 76807a90e97SDavid Howells lookup_busy: 76907a90e97SDavid Howells ret = -EBUSY; 77007a90e97SDavid Howells lookup_put: 77107a90e97SDavid Howells inode_unlock(d_inode(dir)); 77207a90e97SDavid Howells dput(victim); 77307a90e97SDavid Howells return ERR_PTR(ret); 77407a90e97SDavid Howells 77507a90e97SDavid Howells lookup_error: 77607a90e97SDavid Howells inode_unlock(d_inode(dir)); 77707a90e97SDavid Howells ret = PTR_ERR(victim); 77807a90e97SDavid Howells if (ret == -ENOENT) 77907a90e97SDavid Howells return ERR_PTR(-ESTALE); /* Probably got retired by the netfs */ 78007a90e97SDavid Howells 78107a90e97SDavid Howells if (ret == -EIO) { 78207a90e97SDavid Howells cachefiles_io_error(cache, "Lookup failed"); 78307a90e97SDavid Howells } else if (ret != -ENOMEM) { 78407a90e97SDavid Howells pr_err("Internal error: %d\n", ret); 78507a90e97SDavid Howells ret = -EIO; 78607a90e97SDavid Howells } 78707a90e97SDavid Howells 78807a90e97SDavid Howells return ERR_PTR(ret); 78907a90e97SDavid Howells } 79007a90e97SDavid Howells 79107a90e97SDavid Howells /* 79207a90e97SDavid Howells * Cull an object if it's not in use 79307a90e97SDavid Howells * - called only by cache manager daemon 79407a90e97SDavid Howells */ 79507a90e97SDavid Howells int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 79607a90e97SDavid Howells char *filename) 79707a90e97SDavid Howells { 79807a90e97SDavid Howells struct dentry *victim; 79907a90e97SDavid Howells struct inode *inode; 80007a90e97SDavid Howells int ret; 80107a90e97SDavid Howells 80207a90e97SDavid Howells _enter(",%pd/,%s", dir, filename); 80307a90e97SDavid Howells 80407a90e97SDavid Howells victim = cachefiles_lookup_for_cull(cache, dir, filename); 80507a90e97SDavid Howells if (IS_ERR(victim)) 80607a90e97SDavid Howells return PTR_ERR(victim); 80707a90e97SDavid Howells 80807a90e97SDavid Howells /* check to see if someone is using this object */ 80907a90e97SDavid Howells inode = d_inode(victim); 81007a90e97SDavid Howells inode_lock(inode); 81107a90e97SDavid Howells if (inode->i_flags & S_KERNEL_FILE) { 81207a90e97SDavid Howells ret = -EBUSY; 81307a90e97SDavid Howells } else { 81407a90e97SDavid Howells /* Stop the cache from picking it back up */ 81507a90e97SDavid Howells inode->i_flags |= S_KERNEL_FILE; 81607a90e97SDavid Howells ret = 0; 81707a90e97SDavid Howells } 81807a90e97SDavid Howells inode_unlock(inode); 81907a90e97SDavid Howells if (ret < 0) 82007a90e97SDavid Howells goto error_unlock; 82107a90e97SDavid Howells 82207a90e97SDavid Howells ret = cachefiles_bury_object(cache, NULL, dir, victim, 82307a90e97SDavid Howells FSCACHE_OBJECT_WAS_CULLED); 82407a90e97SDavid Howells if (ret < 0) 82507a90e97SDavid Howells goto error; 82607a90e97SDavid Howells 8279f08ebc3SDavid Howells fscache_count_culled(); 82807a90e97SDavid Howells dput(victim); 82907a90e97SDavid Howells _leave(" = 0"); 83007a90e97SDavid Howells return 0; 83107a90e97SDavid Howells 83207a90e97SDavid Howells error_unlock: 83307a90e97SDavid Howells inode_unlock(d_inode(dir)); 83407a90e97SDavid Howells error: 83507a90e97SDavid Howells dput(victim); 83607a90e97SDavid Howells if (ret == -ENOENT) 83707a90e97SDavid Howells return -ESTALE; /* Probably got retired by the netfs */ 83807a90e97SDavid Howells 83907a90e97SDavid Howells if (ret != -ENOMEM) { 84007a90e97SDavid Howells pr_err("Internal error: %d\n", ret); 84107a90e97SDavid Howells ret = -EIO; 84207a90e97SDavid Howells } 84307a90e97SDavid Howells 84407a90e97SDavid Howells _leave(" = %d", ret); 84507a90e97SDavid Howells return ret; 84607a90e97SDavid Howells } 84707a90e97SDavid Howells 84807a90e97SDavid Howells /* 84907a90e97SDavid Howells * Find out if an object is in use or not 85007a90e97SDavid Howells * - called only by cache manager daemon 85107a90e97SDavid Howells * - returns -EBUSY or 0 to indicate whether an object is in use or not 85207a90e97SDavid Howells */ 85307a90e97SDavid Howells int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir, 85407a90e97SDavid Howells char *filename) 85507a90e97SDavid Howells { 85607a90e97SDavid Howells struct dentry *victim; 85707a90e97SDavid Howells int ret = 0; 85807a90e97SDavid Howells 85907a90e97SDavid Howells victim = cachefiles_lookup_for_cull(cache, dir, filename); 86007a90e97SDavid Howells if (IS_ERR(victim)) 86107a90e97SDavid Howells return PTR_ERR(victim); 86207a90e97SDavid Howells 86307a90e97SDavid Howells inode_unlock(d_inode(dir)); 86407a90e97SDavid Howells dput(victim); 86507a90e97SDavid Howells return ret; 86607a90e97SDavid Howells } 867