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, 1808d7a6fbSMiklos Szeredi struct inode *inode) 191bd9c4e4SDavid Howells { 201bd9c4e4SDavid Howells bool can_use = false; 211bd9c4e4SDavid Howells 221bd9c4e4SDavid Howells if (!(inode->i_flags & S_KERNEL_FILE)) { 231bd9c4e4SDavid Howells inode->i_flags |= S_KERNEL_FILE; 241bd9c4e4SDavid Howells trace_cachefiles_mark_active(object, inode); 251bd9c4e4SDavid Howells can_use = true; 261bd9c4e4SDavid Howells } else { 27b64a3314SDavid Howells trace_cachefiles_mark_failed(object, inode); 281bd9c4e4SDavid Howells } 291bd9c4e4SDavid Howells 301bd9c4e4SDavid Howells return can_use; 311bd9c4e4SDavid Howells } 321bd9c4e4SDavid Howells 33169379eaSDavid Howells static bool cachefiles_mark_inode_in_use(struct cachefiles_object *object, 3408d7a6fbSMiklos Szeredi struct inode *inode) 35169379eaSDavid Howells { 36169379eaSDavid Howells bool can_use; 37169379eaSDavid Howells 38169379eaSDavid Howells inode_lock(inode); 3908d7a6fbSMiklos Szeredi can_use = __cachefiles_mark_inode_in_use(object, inode); 40169379eaSDavid Howells inode_unlock(inode); 41169379eaSDavid Howells return can_use; 42169379eaSDavid Howells } 43169379eaSDavid Howells 441bd9c4e4SDavid Howells /* 451bd9c4e4SDavid Howells * Unmark a backing inode. The caller must hold the inode lock. 461bd9c4e4SDavid Howells */ 471bd9c4e4SDavid Howells static void __cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 4808d7a6fbSMiklos Szeredi struct inode *inode) 491bd9c4e4SDavid Howells { 501bd9c4e4SDavid Howells inode->i_flags &= ~S_KERNEL_FILE; 511bd9c4e4SDavid Howells trace_cachefiles_mark_inactive(object, inode); 521bd9c4e4SDavid Howells } 5332759f7dSDavid Howells 54ea5dc046SJeffle Xu static void cachefiles_do_unmark_inode_in_use(struct cachefiles_object *object, 5508d7a6fbSMiklos Szeredi struct inode *inode) 56ea5dc046SJeffle Xu { 57ea5dc046SJeffle Xu inode_lock(inode); 5808d7a6fbSMiklos Szeredi __cachefiles_unmark_inode_in_use(object, inode); 59ea5dc046SJeffle Xu inode_unlock(inode); 60ea5dc046SJeffle Xu } 61ea5dc046SJeffle Xu 6232759f7dSDavid Howells /* 63169379eaSDavid Howells * Unmark a backing inode and tell cachefilesd that there's something that can 64169379eaSDavid Howells * be culled. 65169379eaSDavid Howells */ 66169379eaSDavid Howells void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 67169379eaSDavid Howells struct file *file) 68169379eaSDavid Howells { 69169379eaSDavid Howells struct cachefiles_cache *cache = object->volume->cache; 70169379eaSDavid Howells struct inode *inode = file_inode(file); 71169379eaSDavid Howells 7208d7a6fbSMiklos Szeredi cachefiles_do_unmark_inode_in_use(object, inode); 73169379eaSDavid Howells 74169379eaSDavid Howells if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) { 75169379eaSDavid Howells atomic_long_add(inode->i_blocks, &cache->b_released); 76169379eaSDavid Howells if (atomic_inc_return(&cache->f_released)) 77169379eaSDavid Howells cachefiles_state_changed(cache); 78169379eaSDavid Howells } 79169379eaSDavid Howells } 80169379eaSDavid Howells 81169379eaSDavid Howells /* 8232759f7dSDavid Howells * get a subdirectory 8332759f7dSDavid Howells */ 8432759f7dSDavid Howells struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 8532759f7dSDavid Howells struct dentry *dir, 8632759f7dSDavid Howells const char *dirname, 8732759f7dSDavid Howells bool *_is_new) 8832759f7dSDavid Howells { 8932759f7dSDavid Howells struct dentry *subdir; 9032759f7dSDavid Howells struct path path; 9132759f7dSDavid Howells int ret; 9232759f7dSDavid Howells 9332759f7dSDavid Howells _enter(",,%s", dirname); 9432759f7dSDavid Howells 9532759f7dSDavid Howells /* search the current directory for the element name */ 9632759f7dSDavid Howells inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); 9732759f7dSDavid Howells 9832759f7dSDavid Howells retry: 9932759f7dSDavid Howells ret = cachefiles_inject_read_error(); 10032759f7dSDavid Howells if (ret == 0) 10132759f7dSDavid Howells subdir = lookup_one_len(dirname, dir, strlen(dirname)); 10232759f7dSDavid Howells else 10332759f7dSDavid Howells subdir = ERR_PTR(ret); 1048c39b8bcSDavid Howells trace_cachefiles_lookup(NULL, dir, subdir); 10532759f7dSDavid Howells if (IS_ERR(subdir)) { 10632759f7dSDavid Howells trace_cachefiles_vfs_error(NULL, d_backing_inode(dir), 10732759f7dSDavid Howells PTR_ERR(subdir), 10832759f7dSDavid Howells cachefiles_trace_lookup_error); 10932759f7dSDavid Howells if (PTR_ERR(subdir) == -ENOMEM) 11032759f7dSDavid Howells goto nomem_d_alloc; 11132759f7dSDavid Howells goto lookup_error; 11232759f7dSDavid Howells } 11332759f7dSDavid Howells 11432759f7dSDavid Howells _debug("subdir -> %pd %s", 11532759f7dSDavid Howells subdir, d_backing_inode(subdir) ? "positive" : "negative"); 11632759f7dSDavid Howells 11732759f7dSDavid Howells /* we need to create the subdir if it doesn't exist yet */ 11832759f7dSDavid Howells if (d_is_negative(subdir)) { 1193929eca7SDavid Howells ret = cachefiles_has_space(cache, 1, 0, 1203929eca7SDavid Howells cachefiles_has_space_for_create); 12132759f7dSDavid Howells if (ret < 0) 12232759f7dSDavid Howells goto mkdir_error; 12332759f7dSDavid Howells 12432759f7dSDavid Howells _debug("attempt mkdir"); 12532759f7dSDavid Howells 12632759f7dSDavid Howells path.mnt = cache->mnt; 12732759f7dSDavid Howells path.dentry = dir; 12832759f7dSDavid Howells ret = security_path_mkdir(&path, subdir, 0700); 12932759f7dSDavid Howells if (ret < 0) 13032759f7dSDavid Howells goto mkdir_error; 13132759f7dSDavid Howells ret = cachefiles_inject_write_error(); 13232759f7dSDavid Howells if (ret == 0) 133abf08576SChristian Brauner ret = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700); 13432759f7dSDavid Howells if (ret < 0) { 13532759f7dSDavid Howells trace_cachefiles_vfs_error(NULL, d_inode(dir), ret, 13632759f7dSDavid Howells cachefiles_trace_mkdir_error); 13732759f7dSDavid Howells goto mkdir_error; 13832759f7dSDavid Howells } 1398c39b8bcSDavid Howells trace_cachefiles_mkdir(dir, subdir); 14032759f7dSDavid Howells 14132759f7dSDavid Howells if (unlikely(d_unhashed(subdir))) { 14232759f7dSDavid Howells cachefiles_put_directory(subdir); 14332759f7dSDavid Howells goto retry; 14432759f7dSDavid Howells } 14532759f7dSDavid Howells ASSERT(d_backing_inode(subdir)); 14632759f7dSDavid Howells 14732759f7dSDavid Howells _debug("mkdir -> %pd{ino=%lu}", 14832759f7dSDavid Howells subdir, d_backing_inode(subdir)->i_ino); 14932759f7dSDavid Howells if (_is_new) 15032759f7dSDavid Howells *_is_new = true; 15132759f7dSDavid Howells } 15232759f7dSDavid Howells 15332759f7dSDavid Howells /* Tell rmdir() it's not allowed to delete the subdir */ 15432759f7dSDavid Howells inode_lock(d_inode(subdir)); 15532759f7dSDavid Howells inode_unlock(d_inode(dir)); 15632759f7dSDavid Howells 15708d7a6fbSMiklos Szeredi if (!__cachefiles_mark_inode_in_use(NULL, d_inode(subdir))) { 15808d7a6fbSMiklos Szeredi pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n", 15908d7a6fbSMiklos Szeredi subdir, d_inode(subdir)->i_ino); 16032759f7dSDavid Howells goto mark_error; 16108d7a6fbSMiklos Szeredi } 16232759f7dSDavid Howells 16332759f7dSDavid Howells inode_unlock(d_inode(subdir)); 16432759f7dSDavid Howells 16532759f7dSDavid Howells /* we need to make sure the subdir is a directory */ 16632759f7dSDavid Howells ASSERT(d_backing_inode(subdir)); 16732759f7dSDavid Howells 16832759f7dSDavid Howells if (!d_can_lookup(subdir)) { 16932759f7dSDavid Howells pr_err("%s is not a directory\n", dirname); 17032759f7dSDavid Howells ret = -EIO; 17132759f7dSDavid Howells goto check_error; 17232759f7dSDavid Howells } 17332759f7dSDavid Howells 17432759f7dSDavid Howells ret = -EPERM; 17532759f7dSDavid Howells if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) || 17632759f7dSDavid Howells !d_backing_inode(subdir)->i_op->lookup || 17732759f7dSDavid Howells !d_backing_inode(subdir)->i_op->mkdir || 17832759f7dSDavid Howells !d_backing_inode(subdir)->i_op->rename || 17932759f7dSDavid Howells !d_backing_inode(subdir)->i_op->rmdir || 18032759f7dSDavid Howells !d_backing_inode(subdir)->i_op->unlink) 18132759f7dSDavid Howells goto check_error; 18232759f7dSDavid Howells 18332759f7dSDavid Howells _leave(" = [%lu]", d_backing_inode(subdir)->i_ino); 18432759f7dSDavid Howells return subdir; 18532759f7dSDavid Howells 18632759f7dSDavid Howells check_error: 18732759f7dSDavid Howells cachefiles_put_directory(subdir); 18832759f7dSDavid Howells _leave(" = %d [check]", ret); 18932759f7dSDavid Howells return ERR_PTR(ret); 19032759f7dSDavid Howells 19132759f7dSDavid Howells mark_error: 19232759f7dSDavid Howells inode_unlock(d_inode(subdir)); 19332759f7dSDavid Howells dput(subdir); 19432759f7dSDavid Howells return ERR_PTR(-EBUSY); 19532759f7dSDavid Howells 19632759f7dSDavid Howells mkdir_error: 19732759f7dSDavid Howells inode_unlock(d_inode(dir)); 19832759f7dSDavid Howells dput(subdir); 19932759f7dSDavid Howells pr_err("mkdir %s failed with error %d\n", dirname, ret); 20032759f7dSDavid Howells return ERR_PTR(ret); 20132759f7dSDavid Howells 20232759f7dSDavid Howells lookup_error: 20332759f7dSDavid Howells inode_unlock(d_inode(dir)); 20432759f7dSDavid Howells ret = PTR_ERR(subdir); 20532759f7dSDavid Howells pr_err("Lookup %s failed with error %d\n", dirname, ret); 20632759f7dSDavid Howells return ERR_PTR(ret); 20732759f7dSDavid Howells 20832759f7dSDavid Howells nomem_d_alloc: 20932759f7dSDavid Howells inode_unlock(d_inode(dir)); 21032759f7dSDavid Howells _leave(" = -ENOMEM"); 21132759f7dSDavid Howells return ERR_PTR(-ENOMEM); 21232759f7dSDavid Howells } 21332759f7dSDavid Howells 21432759f7dSDavid Howells /* 21532759f7dSDavid Howells * Put a subdirectory. 21632759f7dSDavid Howells */ 21732759f7dSDavid Howells void cachefiles_put_directory(struct dentry *dir) 21832759f7dSDavid Howells { 21932759f7dSDavid Howells if (dir) { 22008d7a6fbSMiklos Szeredi cachefiles_do_unmark_inode_in_use(NULL, d_inode(dir)); 22132759f7dSDavid Howells dput(dir); 22232759f7dSDavid Howells } 22332759f7dSDavid Howells } 22407a90e97SDavid Howells 22507a90e97SDavid Howells /* 22607a90e97SDavid Howells * Remove a regular file from the cache. 22707a90e97SDavid Howells */ 22807a90e97SDavid Howells static int cachefiles_unlink(struct cachefiles_cache *cache, 22907a90e97SDavid Howells struct cachefiles_object *object, 23007a90e97SDavid Howells struct dentry *dir, struct dentry *dentry, 23107a90e97SDavid Howells enum fscache_why_object_killed why) 23207a90e97SDavid Howells { 23307a90e97SDavid Howells struct path path = { 23407a90e97SDavid Howells .mnt = cache->mnt, 23507a90e97SDavid Howells .dentry = dir, 23607a90e97SDavid Howells }; 23707a90e97SDavid Howells int ret; 23807a90e97SDavid Howells 2398c39b8bcSDavid Howells trace_cachefiles_unlink(object, d_inode(dentry)->i_ino, why); 24007a90e97SDavid Howells ret = security_path_unlink(&path, dentry); 24107a90e97SDavid Howells if (ret < 0) { 24207a90e97SDavid Howells cachefiles_io_error(cache, "Unlink security error"); 24307a90e97SDavid Howells return ret; 24407a90e97SDavid Howells } 24507a90e97SDavid Howells 24607a90e97SDavid Howells ret = cachefiles_inject_remove_error(); 24707a90e97SDavid Howells if (ret == 0) { 248abf08576SChristian Brauner ret = vfs_unlink(&nop_mnt_idmap, d_backing_inode(dir), dentry, NULL); 24907a90e97SDavid Howells if (ret == -EIO) 25007a90e97SDavid Howells cachefiles_io_error(cache, "Unlink failed"); 25107a90e97SDavid Howells } 25207a90e97SDavid Howells if (ret != 0) 25307a90e97SDavid Howells trace_cachefiles_vfs_error(object, d_backing_inode(dir), ret, 25407a90e97SDavid Howells cachefiles_trace_unlink_error); 25507a90e97SDavid Howells return ret; 25607a90e97SDavid Howells } 25707a90e97SDavid Howells 25807a90e97SDavid Howells /* 25907a90e97SDavid Howells * Delete an object representation from the cache 26007a90e97SDavid Howells * - File backed objects are unlinked 26107a90e97SDavid Howells * - Directory backed objects are stuffed into the graveyard for userspace to 26207a90e97SDavid Howells * delete 26307a90e97SDavid Howells */ 26407a90e97SDavid Howells int cachefiles_bury_object(struct cachefiles_cache *cache, 26507a90e97SDavid Howells struct cachefiles_object *object, 26607a90e97SDavid Howells struct dentry *dir, 26707a90e97SDavid Howells struct dentry *rep, 26807a90e97SDavid Howells enum fscache_why_object_killed why) 26907a90e97SDavid Howells { 27007a90e97SDavid Howells struct dentry *grave, *trap; 27107a90e97SDavid Howells struct path path, path_to_graveyard; 27207a90e97SDavid Howells char nbuffer[8 + 8 + 1]; 27307a90e97SDavid Howells int ret; 27407a90e97SDavid Howells 27507a90e97SDavid Howells _enter(",'%pd','%pd'", dir, rep); 27607a90e97SDavid Howells 27707a90e97SDavid Howells if (rep->d_parent != dir) { 27807a90e97SDavid Howells inode_unlock(d_inode(dir)); 27907a90e97SDavid Howells _leave(" = -ESTALE"); 28007a90e97SDavid Howells return -ESTALE; 28107a90e97SDavid Howells } 28207a90e97SDavid Howells 28307a90e97SDavid Howells /* non-directories can just be unlinked */ 28407a90e97SDavid Howells if (!d_is_dir(rep)) { 28507a90e97SDavid Howells dget(rep); /* Stop the dentry being negated if it's only pinned 28607a90e97SDavid Howells * by a file struct. 28707a90e97SDavid Howells */ 28807a90e97SDavid Howells ret = cachefiles_unlink(cache, object, dir, rep, why); 28907a90e97SDavid Howells dput(rep); 29007a90e97SDavid Howells 29107a90e97SDavid Howells inode_unlock(d_inode(dir)); 29207a90e97SDavid Howells _leave(" = %d", ret); 29307a90e97SDavid Howells return ret; 29407a90e97SDavid Howells } 29507a90e97SDavid Howells 29607a90e97SDavid Howells /* directories have to be moved to the graveyard */ 29707a90e97SDavid Howells _debug("move stale object to graveyard"); 29807a90e97SDavid Howells inode_unlock(d_inode(dir)); 29907a90e97SDavid Howells 30007a90e97SDavid Howells try_again: 30107a90e97SDavid Howells /* first step is to make up a grave dentry in the graveyard */ 30207a90e97SDavid Howells sprintf(nbuffer, "%08x%08x", 30307a90e97SDavid Howells (uint32_t) ktime_get_real_seconds(), 30407a90e97SDavid Howells (uint32_t) atomic_inc_return(&cache->gravecounter)); 30507a90e97SDavid Howells 30607a90e97SDavid Howells /* do the multiway lock magic */ 30707a90e97SDavid Howells trap = lock_rename(cache->graveyard, dir); 30807a90e97SDavid Howells 30907a90e97SDavid Howells /* do some checks before getting the grave dentry */ 31007a90e97SDavid Howells if (rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) { 31107a90e97SDavid Howells /* the entry was probably culled when we dropped the parent dir 31207a90e97SDavid Howells * lock */ 31307a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 31407a90e97SDavid Howells _leave(" = 0 [culled?]"); 31507a90e97SDavid Howells return 0; 31607a90e97SDavid Howells } 31707a90e97SDavid Howells 31807a90e97SDavid Howells if (!d_can_lookup(cache->graveyard)) { 31907a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 32007a90e97SDavid Howells cachefiles_io_error(cache, "Graveyard no longer a directory"); 32107a90e97SDavid Howells return -EIO; 32207a90e97SDavid Howells } 32307a90e97SDavid Howells 32407a90e97SDavid Howells if (trap == rep) { 32507a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 32607a90e97SDavid Howells cachefiles_io_error(cache, "May not make directory loop"); 32707a90e97SDavid Howells return -EIO; 32807a90e97SDavid Howells } 32907a90e97SDavid Howells 33007a90e97SDavid Howells if (d_mountpoint(rep)) { 33107a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 33207a90e97SDavid Howells cachefiles_io_error(cache, "Mountpoint in cache"); 33307a90e97SDavid Howells return -EIO; 33407a90e97SDavid Howells } 33507a90e97SDavid Howells 33607a90e97SDavid Howells grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer)); 33707a90e97SDavid Howells if (IS_ERR(grave)) { 33807a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 33907a90e97SDavid Howells trace_cachefiles_vfs_error(object, d_inode(cache->graveyard), 34007a90e97SDavid Howells PTR_ERR(grave), 34107a90e97SDavid Howells cachefiles_trace_lookup_error); 34207a90e97SDavid Howells 34307a90e97SDavid Howells if (PTR_ERR(grave) == -ENOMEM) { 34407a90e97SDavid Howells _leave(" = -ENOMEM"); 34507a90e97SDavid Howells return -ENOMEM; 34607a90e97SDavid Howells } 34707a90e97SDavid Howells 34807a90e97SDavid Howells cachefiles_io_error(cache, "Lookup error %ld", PTR_ERR(grave)); 34907a90e97SDavid Howells return -EIO; 35007a90e97SDavid Howells } 35107a90e97SDavid Howells 35207a90e97SDavid Howells if (d_is_positive(grave)) { 35307a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 35407a90e97SDavid Howells dput(grave); 35507a90e97SDavid Howells grave = NULL; 35607a90e97SDavid Howells cond_resched(); 35707a90e97SDavid Howells goto try_again; 35807a90e97SDavid Howells } 35907a90e97SDavid Howells 36007a90e97SDavid Howells if (d_mountpoint(grave)) { 36107a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 36207a90e97SDavid Howells dput(grave); 36307a90e97SDavid Howells cachefiles_io_error(cache, "Mountpoint in graveyard"); 36407a90e97SDavid Howells return -EIO; 36507a90e97SDavid Howells } 36607a90e97SDavid Howells 36707a90e97SDavid Howells /* target should not be an ancestor of source */ 36807a90e97SDavid Howells if (trap == grave) { 36907a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 37007a90e97SDavid Howells dput(grave); 37107a90e97SDavid Howells cachefiles_io_error(cache, "May not make directory loop"); 37207a90e97SDavid Howells return -EIO; 37307a90e97SDavid Howells } 37407a90e97SDavid Howells 37507a90e97SDavid Howells /* attempt the rename */ 37607a90e97SDavid Howells path.mnt = cache->mnt; 37707a90e97SDavid Howells path.dentry = dir; 37807a90e97SDavid Howells path_to_graveyard.mnt = cache->mnt; 37907a90e97SDavid Howells path_to_graveyard.dentry = cache->graveyard; 38007a90e97SDavid Howells ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0); 38107a90e97SDavid Howells if (ret < 0) { 38207a90e97SDavid Howells cachefiles_io_error(cache, "Rename security error %d", ret); 38307a90e97SDavid Howells } else { 38407a90e97SDavid Howells struct renamedata rd = { 385abf08576SChristian Brauner .old_mnt_idmap = &nop_mnt_idmap, 38607a90e97SDavid Howells .old_dir = d_inode(dir), 38707a90e97SDavid Howells .old_dentry = rep, 388abf08576SChristian Brauner .new_mnt_idmap = &nop_mnt_idmap, 38907a90e97SDavid Howells .new_dir = d_inode(cache->graveyard), 39007a90e97SDavid Howells .new_dentry = grave, 39107a90e97SDavid Howells }; 3928c39b8bcSDavid Howells trace_cachefiles_rename(object, d_inode(rep)->i_ino, why); 39307a90e97SDavid Howells ret = cachefiles_inject_read_error(); 39407a90e97SDavid Howells if (ret == 0) 39507a90e97SDavid Howells ret = vfs_rename(&rd); 39607a90e97SDavid Howells if (ret != 0) 39707a90e97SDavid Howells trace_cachefiles_vfs_error(object, d_inode(dir), ret, 39807a90e97SDavid Howells cachefiles_trace_rename_error); 39907a90e97SDavid Howells if (ret != 0 && ret != -ENOMEM) 40007a90e97SDavid Howells cachefiles_io_error(cache, 40107a90e97SDavid Howells "Rename failed with error %d", ret); 40207a90e97SDavid Howells } 40307a90e97SDavid Howells 40408d7a6fbSMiklos Szeredi __cachefiles_unmark_inode_in_use(object, d_inode(rep)); 40507a90e97SDavid Howells unlock_rename(cache->graveyard, dir); 40607a90e97SDavid Howells dput(grave); 40707a90e97SDavid Howells _leave(" = 0"); 40807a90e97SDavid Howells return 0; 40907a90e97SDavid Howells } 41007a90e97SDavid Howells 41107a90e97SDavid Howells /* 4121f08c925SDavid Howells * Delete a cache file. 4131f08c925SDavid Howells */ 4141f08c925SDavid Howells int cachefiles_delete_object(struct cachefiles_object *object, 4151f08c925SDavid Howells enum fscache_why_object_killed why) 4161f08c925SDavid Howells { 4171f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 4181f08c925SDavid Howells struct dentry *dentry = object->file->f_path.dentry; 4191f08c925SDavid Howells struct dentry *fan = volume->fanout[(u8)object->cookie->key_hash]; 4201f08c925SDavid Howells int ret; 4211f08c925SDavid Howells 4221f08c925SDavid Howells _enter(",OBJ%x{%pD}", object->debug_id, object->file); 4231f08c925SDavid Howells 4241f08c925SDavid Howells /* Stop the dentry being negated if it's only pinned by a file struct. */ 4251f08c925SDavid Howells dget(dentry); 4261f08c925SDavid Howells 4271f08c925SDavid Howells inode_lock_nested(d_backing_inode(fan), I_MUTEX_PARENT); 4281f08c925SDavid Howells ret = cachefiles_unlink(volume->cache, object, fan, dentry, why); 4291f08c925SDavid Howells inode_unlock(d_backing_inode(fan)); 4301f08c925SDavid Howells dput(dentry); 4311f08c925SDavid Howells return ret; 4321f08c925SDavid Howells } 4331f08c925SDavid Howells 4341f08c925SDavid Howells /* 4351f08c925SDavid Howells * Create a temporary file and leave it unattached and un-xattr'd until the 4361f08c925SDavid Howells * time comes to discard the object from memory. 4371f08c925SDavid Howells */ 4381f08c925SDavid Howells struct file *cachefiles_create_tmpfile(struct cachefiles_object *object) 4391f08c925SDavid Howells { 4401f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 4411f08c925SDavid Howells struct cachefiles_cache *cache = volume->cache; 4421f08c925SDavid Howells const struct cred *saved_cred; 4431f08c925SDavid Howells struct dentry *fan = volume->fanout[(u8)object->cookie->key_hash]; 4441f08c925SDavid Howells struct file *file; 44524a81759SMiklos Szeredi const struct path parentpath = { .mnt = cache->mnt, .dentry = fan }; 446c8383054SJeffle Xu uint64_t ni_size; 4471f08c925SDavid Howells long ret; 4481f08c925SDavid Howells 4491f08c925SDavid Howells 4501f08c925SDavid Howells cachefiles_begin_secure(cache, &saved_cred); 4511f08c925SDavid Howells 4521f08c925SDavid Howells ret = cachefiles_inject_write_error(); 45338017d44SMiklos Szeredi if (ret == 0) { 454*d56e0ddbSAmir Goldstein file = kernel_tmpfile_open(&nop_mnt_idmap, &parentpath, S_IFREG, 45524a81759SMiklos Szeredi O_RDWR | O_LARGEFILE | O_DIRECT, 45624a81759SMiklos Szeredi cache->cache_cred); 45724a81759SMiklos Szeredi ret = PTR_ERR_OR_ZERO(file); 45838017d44SMiklos Szeredi } 45938017d44SMiklos Szeredi if (ret) { 46038017d44SMiklos Szeredi trace_cachefiles_vfs_error(object, d_inode(fan), ret, 4611f08c925SDavid Howells cachefiles_trace_tmpfile_error); 46238017d44SMiklos Szeredi if (ret == -EIO) 4631f08c925SDavid Howells cachefiles_io_error_obj(object, "Failed to create tmpfile"); 46438017d44SMiklos Szeredi goto err; 4651f08c925SDavid Howells } 4661f08c925SDavid Howells 46724a81759SMiklos Szeredi trace_cachefiles_tmpfile(object, file_inode(file)); 4681f08c925SDavid Howells 46908d7a6fbSMiklos Szeredi /* This is a newly created file with no other possible user */ 47024a81759SMiklos Szeredi if (!cachefiles_mark_inode_in_use(object, file_inode(file))) 47108d7a6fbSMiklos Szeredi WARN_ON(1); 4721f08c925SDavid Howells 473c8383054SJeffle Xu ret = cachefiles_ondemand_init_object(object); 47438017d44SMiklos Szeredi if (ret < 0) 47538017d44SMiklos Szeredi goto err_unuse; 476c8383054SJeffle Xu 477c8383054SJeffle Xu ni_size = object->cookie->object_size; 478c8383054SJeffle Xu ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE); 479c8383054SJeffle Xu 4801f08c925SDavid Howells if (ni_size > 0) { 48124a81759SMiklos Szeredi trace_cachefiles_trunc(object, file_inode(file), 0, ni_size, 4821f08c925SDavid Howells cachefiles_trunc_expand_tmpfile); 4831f08c925SDavid Howells ret = cachefiles_inject_write_error(); 4841f08c925SDavid Howells if (ret == 0) 48524a81759SMiklos Szeredi ret = vfs_truncate(&file->f_path, ni_size); 4861f08c925SDavid Howells if (ret < 0) { 4871f08c925SDavid Howells trace_cachefiles_vfs_error( 48824a81759SMiklos Szeredi object, file_inode(file), ret, 4891f08c925SDavid Howells cachefiles_trace_trunc_error); 49038017d44SMiklos Szeredi goto err_unuse; 4911f08c925SDavid Howells } 4921f08c925SDavid Howells } 4931f08c925SDavid Howells 49438017d44SMiklos Szeredi ret = -EINVAL; 4951f08c925SDavid Howells if (unlikely(!file->f_op->read_iter) || 4961f08c925SDavid Howells unlikely(!file->f_op->write_iter)) { 4971f08c925SDavid Howells fput(file); 4981f08c925SDavid Howells pr_notice("Cache does not support read_iter and write_iter\n"); 49938017d44SMiklos Szeredi goto err_unuse; 5001f08c925SDavid Howells } 5011f08c925SDavid Howells out: 5021f08c925SDavid Howells cachefiles_end_secure(cache, saved_cred); 5031f08c925SDavid Howells return file; 50438017d44SMiklos Szeredi 50538017d44SMiklos Szeredi err_unuse: 50624a81759SMiklos Szeredi cachefiles_do_unmark_inode_in_use(object, file_inode(file)); 50724a81759SMiklos Szeredi fput(file); 50838017d44SMiklos Szeredi err: 50938017d44SMiklos Szeredi file = ERR_PTR(ret); 51038017d44SMiklos Szeredi goto out; 5111f08c925SDavid Howells } 5121f08c925SDavid Howells 5131f08c925SDavid Howells /* 5141f08c925SDavid Howells * Create a new file. 5151f08c925SDavid Howells */ 5161f08c925SDavid Howells static bool cachefiles_create_file(struct cachefiles_object *object) 5171f08c925SDavid Howells { 5181f08c925SDavid Howells struct file *file; 5191f08c925SDavid Howells int ret; 5201f08c925SDavid Howells 5213929eca7SDavid Howells ret = cachefiles_has_space(object->volume->cache, 1, 0, 5223929eca7SDavid Howells cachefiles_has_space_for_create); 5231f08c925SDavid Howells if (ret < 0) 5241f08c925SDavid Howells return false; 5251f08c925SDavid Howells 5261f08c925SDavid Howells file = cachefiles_create_tmpfile(object); 5271f08c925SDavid Howells if (IS_ERR(file)) 5281f08c925SDavid Howells return false; 5291f08c925SDavid Howells 5301f08c925SDavid Howells set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags); 5311f08c925SDavid Howells set_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags); 5321f08c925SDavid Howells _debug("create -> %pD{ino=%lu}", file, file_inode(file)->i_ino); 5331f08c925SDavid Howells object->file = file; 5341f08c925SDavid Howells return true; 5351f08c925SDavid Howells } 5361f08c925SDavid Howells 5371f08c925SDavid Howells /* 5381f08c925SDavid Howells * Open an existing file, checking its attributes and replacing it if it is 5391f08c925SDavid Howells * stale. 5401f08c925SDavid Howells */ 5411f08c925SDavid Howells static bool cachefiles_open_file(struct cachefiles_object *object, 5421f08c925SDavid Howells struct dentry *dentry) 5431f08c925SDavid Howells { 5441f08c925SDavid Howells struct cachefiles_cache *cache = object->volume->cache; 5451f08c925SDavid Howells struct file *file; 5461f08c925SDavid Howells struct path path; 5471f08c925SDavid Howells int ret; 5481f08c925SDavid Howells 5491f08c925SDavid Howells _enter("%pd", dentry); 5501f08c925SDavid Howells 55108d7a6fbSMiklos Szeredi if (!cachefiles_mark_inode_in_use(object, d_inode(dentry))) { 55208d7a6fbSMiklos Szeredi pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n", 55308d7a6fbSMiklos Szeredi dentry, d_inode(dentry)->i_ino); 5541f08c925SDavid Howells return false; 55508d7a6fbSMiklos Szeredi } 5561f08c925SDavid Howells 5571f08c925SDavid Howells /* We need to open a file interface onto a data file now as we can't do 5581f08c925SDavid Howells * it on demand because writeback called from do_exit() sees 5591f08c925SDavid Howells * current->fs == NULL - which breaks d_path() called from ext4 open. 5601f08c925SDavid Howells */ 5611f08c925SDavid Howells path.mnt = cache->mnt; 5621f08c925SDavid Howells path.dentry = dentry; 5631f08c925SDavid Howells file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT, 5641f08c925SDavid Howells d_backing_inode(dentry), cache->cache_cred); 5651f08c925SDavid Howells if (IS_ERR(file)) { 5661f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_backing_inode(dentry), 5671f08c925SDavid Howells PTR_ERR(file), 5681f08c925SDavid Howells cachefiles_trace_open_error); 5691f08c925SDavid Howells goto error; 5701f08c925SDavid Howells } 5711f08c925SDavid Howells 5721f08c925SDavid Howells if (unlikely(!file->f_op->read_iter) || 5731f08c925SDavid Howells unlikely(!file->f_op->write_iter)) { 5741f08c925SDavid Howells pr_notice("Cache does not support read_iter and write_iter\n"); 5751f08c925SDavid Howells goto error_fput; 5761f08c925SDavid Howells } 5771f08c925SDavid Howells _debug("file -> %pd positive", dentry); 5781f08c925SDavid Howells 579c8383054SJeffle Xu ret = cachefiles_ondemand_init_object(object); 580c8383054SJeffle Xu if (ret < 0) 581c8383054SJeffle Xu goto error_fput; 582c8383054SJeffle Xu 5831f08c925SDavid Howells ret = cachefiles_check_auxdata(object, file); 5841f08c925SDavid Howells if (ret < 0) 5851f08c925SDavid Howells goto check_failed; 5861f08c925SDavid Howells 5871f08c925SDavid Howells object->file = file; 5881f08c925SDavid Howells 5891f08c925SDavid Howells /* Always update the atime on an object we've just looked up (this is 5901f08c925SDavid Howells * used to keep track of culling, and atimes are only updated by read, 5911f08c925SDavid Howells * write and readdir but not lookup or open). 5921f08c925SDavid Howells */ 5931f08c925SDavid Howells touch_atime(&file->f_path); 5941f08c925SDavid Howells dput(dentry); 5951f08c925SDavid Howells return true; 5961f08c925SDavid Howells 5971f08c925SDavid Howells check_failed: 5981f08c925SDavid Howells fscache_cookie_lookup_negative(object->cookie); 5991f08c925SDavid Howells cachefiles_unmark_inode_in_use(object, file); 6001f08c925SDavid Howells fput(file); 6011f08c925SDavid Howells dput(dentry); 602ea5dc046SJeffle Xu if (ret == -ESTALE) 6031f08c925SDavid Howells return cachefiles_create_file(object); 604ea5dc046SJeffle Xu return false; 605ea5dc046SJeffle Xu 6061f08c925SDavid Howells error_fput: 6071f08c925SDavid Howells fput(file); 6081f08c925SDavid Howells error: 60908d7a6fbSMiklos Szeredi cachefiles_do_unmark_inode_in_use(object, d_inode(dentry)); 6101f08c925SDavid Howells dput(dentry); 6111f08c925SDavid Howells return false; 6121f08c925SDavid Howells } 6131f08c925SDavid Howells 6141f08c925SDavid Howells /* 6151f08c925SDavid Howells * walk from the parent object to the child object through the backing 6161f08c925SDavid Howells * filesystem, creating directories as we go 6171f08c925SDavid Howells */ 6181f08c925SDavid Howells bool cachefiles_look_up_object(struct cachefiles_object *object) 6191f08c925SDavid Howells { 6201f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 6211f08c925SDavid Howells struct dentry *dentry, *fan = volume->fanout[(u8)object->cookie->key_hash]; 6221f08c925SDavid Howells int ret; 6231f08c925SDavid Howells 6241f08c925SDavid Howells _enter("OBJ%x,%s,", object->debug_id, object->d_name); 6251f08c925SDavid Howells 6261f08c925SDavid Howells /* Look up path "cache/vol/fanout/file". */ 6271f08c925SDavid Howells ret = cachefiles_inject_read_error(); 6281f08c925SDavid Howells if (ret == 0) 6291f08c925SDavid Howells dentry = lookup_positive_unlocked(object->d_name, fan, 6301f08c925SDavid Howells object->d_name_len); 6311f08c925SDavid Howells else 6321f08c925SDavid Howells dentry = ERR_PTR(ret); 6338c39b8bcSDavid Howells trace_cachefiles_lookup(object, fan, dentry); 6341f08c925SDavid Howells if (IS_ERR(dentry)) { 6351f08c925SDavid Howells if (dentry == ERR_PTR(-ENOENT)) 6361f08c925SDavid Howells goto new_file; 6371f08c925SDavid Howells if (dentry == ERR_PTR(-EIO)) 6381f08c925SDavid Howells cachefiles_io_error_obj(object, "Lookup failed"); 6391f08c925SDavid Howells return false; 6401f08c925SDavid Howells } 6411f08c925SDavid Howells 6421f08c925SDavid Howells if (!d_is_reg(dentry)) { 6431f08c925SDavid Howells pr_err("%pd is not a file\n", dentry); 6441f08c925SDavid Howells inode_lock_nested(d_inode(fan), I_MUTEX_PARENT); 6451f08c925SDavid Howells ret = cachefiles_bury_object(volume->cache, object, fan, dentry, 6461f08c925SDavid Howells FSCACHE_OBJECT_IS_WEIRD); 6471f08c925SDavid Howells dput(dentry); 6481f08c925SDavid Howells if (ret < 0) 6491f08c925SDavid Howells return false; 6501f08c925SDavid Howells goto new_file; 6511f08c925SDavid Howells } 6521f08c925SDavid Howells 6531f08c925SDavid Howells if (!cachefiles_open_file(object, dentry)) 6541f08c925SDavid Howells return false; 6551f08c925SDavid Howells 6561f08c925SDavid Howells _leave(" = t [%lu]", file_inode(object->file)->i_ino); 6571f08c925SDavid Howells return true; 6581f08c925SDavid Howells 6591f08c925SDavid Howells new_file: 6601f08c925SDavid Howells fscache_cookie_lookup_negative(object->cookie); 6611f08c925SDavid Howells return cachefiles_create_file(object); 6621f08c925SDavid Howells } 6631f08c925SDavid Howells 6641f08c925SDavid Howells /* 6651f08c925SDavid Howells * Attempt to link a temporary file into its rightful place in the cache. 6661f08c925SDavid Howells */ 6671f08c925SDavid Howells bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, 6681f08c925SDavid Howells struct cachefiles_object *object) 6691f08c925SDavid Howells { 6701f08c925SDavid Howells struct cachefiles_volume *volume = object->volume; 6711f08c925SDavid Howells struct dentry *dentry, *fan = volume->fanout[(u8)object->cookie->key_hash]; 6721f08c925SDavid Howells bool success = false; 6731f08c925SDavid Howells int ret; 6741f08c925SDavid Howells 6751f08c925SDavid Howells _enter(",%pD", object->file); 6761f08c925SDavid Howells 6771f08c925SDavid Howells inode_lock_nested(d_inode(fan), I_MUTEX_PARENT); 6781f08c925SDavid Howells ret = cachefiles_inject_read_error(); 6791f08c925SDavid Howells if (ret == 0) 6801f08c925SDavid Howells dentry = lookup_one_len(object->d_name, fan, object->d_name_len); 6811f08c925SDavid Howells else 6821f08c925SDavid Howells dentry = ERR_PTR(ret); 6831f08c925SDavid Howells if (IS_ERR(dentry)) { 6841f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry), 6851f08c925SDavid Howells cachefiles_trace_lookup_error); 6861f08c925SDavid Howells _debug("lookup fail %ld", PTR_ERR(dentry)); 6871f08c925SDavid Howells goto out_unlock; 6881f08c925SDavid Howells } 6891f08c925SDavid Howells 6901f08c925SDavid Howells if (!d_is_negative(dentry)) { 6911f08c925SDavid Howells if (d_backing_inode(dentry) == file_inode(object->file)) { 6921f08c925SDavid Howells success = true; 6931f08c925SDavid Howells goto out_dput; 6941f08c925SDavid Howells } 6951f08c925SDavid Howells 6961f08c925SDavid Howells ret = cachefiles_unlink(volume->cache, object, fan, dentry, 6971f08c925SDavid Howells FSCACHE_OBJECT_IS_STALE); 6981f08c925SDavid Howells if (ret < 0) 6991f08c925SDavid Howells goto out_dput; 7001f08c925SDavid Howells 7011f08c925SDavid Howells dput(dentry); 7021f08c925SDavid Howells ret = cachefiles_inject_read_error(); 7031f08c925SDavid Howells if (ret == 0) 7041f08c925SDavid Howells dentry = lookup_one_len(object->d_name, fan, object->d_name_len); 7051f08c925SDavid Howells else 7061f08c925SDavid Howells dentry = ERR_PTR(ret); 7071f08c925SDavid Howells if (IS_ERR(dentry)) { 7081f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry), 7091f08c925SDavid Howells cachefiles_trace_lookup_error); 7101f08c925SDavid Howells _debug("lookup fail %ld", PTR_ERR(dentry)); 7111f08c925SDavid Howells goto out_unlock; 7121f08c925SDavid Howells } 7131f08c925SDavid Howells } 7141f08c925SDavid Howells 7151f08c925SDavid Howells ret = cachefiles_inject_read_error(); 7161f08c925SDavid Howells if (ret == 0) 717abf08576SChristian Brauner ret = vfs_link(object->file->f_path.dentry, &nop_mnt_idmap, 7181f08c925SDavid Howells d_inode(fan), dentry, NULL); 7191f08c925SDavid Howells if (ret < 0) { 7201f08c925SDavid Howells trace_cachefiles_vfs_error(object, d_inode(fan), ret, 7211f08c925SDavid Howells cachefiles_trace_link_error); 7221f08c925SDavid Howells _debug("link fail %d", ret); 7231f08c925SDavid Howells } else { 7241f08c925SDavid Howells trace_cachefiles_link(object, file_inode(object->file)); 7251f08c925SDavid Howells spin_lock(&object->lock); 7261f08c925SDavid Howells /* TODO: Do we want to switch the file pointer to the new dentry? */ 7271f08c925SDavid Howells clear_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags); 7281f08c925SDavid Howells spin_unlock(&object->lock); 7291f08c925SDavid Howells success = true; 7301f08c925SDavid Howells } 7311f08c925SDavid Howells 7321f08c925SDavid Howells out_dput: 7331f08c925SDavid Howells dput(dentry); 7341f08c925SDavid Howells out_unlock: 7351f08c925SDavid Howells inode_unlock(d_inode(fan)); 7361f08c925SDavid Howells _leave(" = %u", success); 7371f08c925SDavid Howells return success; 7381f08c925SDavid Howells } 7391f08c925SDavid Howells 7401f08c925SDavid Howells /* 74107a90e97SDavid Howells * Look up an inode to be checked or culled. Return -EBUSY if the inode is 74207a90e97SDavid Howells * marked in use. 74307a90e97SDavid Howells */ 74407a90e97SDavid Howells static struct dentry *cachefiles_lookup_for_cull(struct cachefiles_cache *cache, 74507a90e97SDavid Howells struct dentry *dir, 74607a90e97SDavid Howells char *filename) 74707a90e97SDavid Howells { 74807a90e97SDavid Howells struct dentry *victim; 74907a90e97SDavid Howells int ret = -ENOENT; 75007a90e97SDavid Howells 75107a90e97SDavid Howells inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); 75207a90e97SDavid Howells 75307a90e97SDavid Howells victim = lookup_one_len(filename, dir, strlen(filename)); 75407a90e97SDavid Howells if (IS_ERR(victim)) 75507a90e97SDavid Howells goto lookup_error; 75607a90e97SDavid Howells if (d_is_negative(victim)) 75707a90e97SDavid Howells goto lookup_put; 75807a90e97SDavid Howells if (d_inode(victim)->i_flags & S_KERNEL_FILE) 75907a90e97SDavid Howells goto lookup_busy; 76007a90e97SDavid Howells return victim; 76107a90e97SDavid Howells 76207a90e97SDavid Howells lookup_busy: 76307a90e97SDavid Howells ret = -EBUSY; 76407a90e97SDavid Howells lookup_put: 76507a90e97SDavid Howells inode_unlock(d_inode(dir)); 76607a90e97SDavid Howells dput(victim); 76707a90e97SDavid Howells return ERR_PTR(ret); 76807a90e97SDavid Howells 76907a90e97SDavid Howells lookup_error: 77007a90e97SDavid Howells inode_unlock(d_inode(dir)); 77107a90e97SDavid Howells ret = PTR_ERR(victim); 77207a90e97SDavid Howells if (ret == -ENOENT) 77307a90e97SDavid Howells return ERR_PTR(-ESTALE); /* Probably got retired by the netfs */ 77407a90e97SDavid Howells 77507a90e97SDavid Howells if (ret == -EIO) { 77607a90e97SDavid Howells cachefiles_io_error(cache, "Lookup failed"); 77707a90e97SDavid Howells } else if (ret != -ENOMEM) { 77807a90e97SDavid Howells pr_err("Internal error: %d\n", ret); 77907a90e97SDavid Howells ret = -EIO; 78007a90e97SDavid Howells } 78107a90e97SDavid Howells 78207a90e97SDavid Howells return ERR_PTR(ret); 78307a90e97SDavid Howells } 78407a90e97SDavid Howells 78507a90e97SDavid Howells /* 78607a90e97SDavid Howells * Cull an object if it's not in use 78707a90e97SDavid Howells * - called only by cache manager daemon 78807a90e97SDavid Howells */ 78907a90e97SDavid Howells int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 79007a90e97SDavid Howells char *filename) 79107a90e97SDavid Howells { 79207a90e97SDavid Howells struct dentry *victim; 79307a90e97SDavid Howells struct inode *inode; 79407a90e97SDavid Howells int ret; 79507a90e97SDavid Howells 79607a90e97SDavid Howells _enter(",%pd/,%s", dir, filename); 79707a90e97SDavid Howells 79807a90e97SDavid Howells victim = cachefiles_lookup_for_cull(cache, dir, filename); 79907a90e97SDavid Howells if (IS_ERR(victim)) 80007a90e97SDavid Howells return PTR_ERR(victim); 80107a90e97SDavid Howells 80207a90e97SDavid Howells /* check to see if someone is using this object */ 80307a90e97SDavid Howells inode = d_inode(victim); 80407a90e97SDavid Howells inode_lock(inode); 80507a90e97SDavid Howells if (inode->i_flags & S_KERNEL_FILE) { 80607a90e97SDavid Howells ret = -EBUSY; 80707a90e97SDavid Howells } else { 80807a90e97SDavid Howells /* Stop the cache from picking it back up */ 80907a90e97SDavid Howells inode->i_flags |= S_KERNEL_FILE; 81007a90e97SDavid Howells ret = 0; 81107a90e97SDavid Howells } 81207a90e97SDavid Howells inode_unlock(inode); 81307a90e97SDavid Howells if (ret < 0) 81407a90e97SDavid Howells goto error_unlock; 81507a90e97SDavid Howells 81607a90e97SDavid Howells ret = cachefiles_bury_object(cache, NULL, dir, victim, 81707a90e97SDavid Howells FSCACHE_OBJECT_WAS_CULLED); 81807a90e97SDavid Howells if (ret < 0) 81907a90e97SDavid Howells goto error; 82007a90e97SDavid Howells 8219f08ebc3SDavid Howells fscache_count_culled(); 82207a90e97SDavid Howells dput(victim); 82307a90e97SDavid Howells _leave(" = 0"); 82407a90e97SDavid Howells return 0; 82507a90e97SDavid Howells 82607a90e97SDavid Howells error_unlock: 82707a90e97SDavid Howells inode_unlock(d_inode(dir)); 82807a90e97SDavid Howells error: 82907a90e97SDavid Howells dput(victim); 83007a90e97SDavid Howells if (ret == -ENOENT) 83107a90e97SDavid Howells return -ESTALE; /* Probably got retired by the netfs */ 83207a90e97SDavid Howells 83307a90e97SDavid Howells if (ret != -ENOMEM) { 83407a90e97SDavid Howells pr_err("Internal error: %d\n", ret); 83507a90e97SDavid Howells ret = -EIO; 83607a90e97SDavid Howells } 83707a90e97SDavid Howells 83807a90e97SDavid Howells _leave(" = %d", ret); 83907a90e97SDavid Howells return ret; 84007a90e97SDavid Howells } 84107a90e97SDavid Howells 84207a90e97SDavid Howells /* 84307a90e97SDavid Howells * Find out if an object is in use or not 84407a90e97SDavid Howells * - called only by cache manager daemon 84507a90e97SDavid Howells * - returns -EBUSY or 0 to indicate whether an object is in use or not 84607a90e97SDavid Howells */ 84707a90e97SDavid Howells int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir, 84807a90e97SDavid Howells char *filename) 84907a90e97SDavid Howells { 85007a90e97SDavid Howells struct dentry *victim; 85107a90e97SDavid Howells int ret = 0; 85207a90e97SDavid Howells 85307a90e97SDavid Howells victim = cachefiles_lookup_for_cull(cache, dir, filename); 85407a90e97SDavid Howells if (IS_ERR(victim)) 85507a90e97SDavid Howells return PTR_ERR(victim); 85607a90e97SDavid Howells 85707a90e97SDavid Howells inode_unlock(d_inode(dir)); 85807a90e97SDavid Howells dput(victim); 85907a90e97SDavid Howells return ret; 86007a90e97SDavid Howells } 861