diff options
Diffstat (limited to 'fs/cachefiles/interface.c')
| -rw-r--r-- | fs/cachefiles/interface.c | 747 |
1 files changed, 310 insertions, 437 deletions
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index da28ac1fa225..51c968cd00a6 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -1,572 +1,445 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* FS-Cache interface to CacheFiles * - * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. * Written by David Howells ([email protected]) */ #include <linux/slab.h> #include <linux/mount.h> +#include <linux/xattr.h> +#include <linux/file.h> +#include <linux/falloc.h> +#include <trace/events/fscache.h> #include "internal.h" -struct cachefiles_lookup_data { - struct cachefiles_xattr *auxdata; /* auxiliary data */ - char *key; /* key path */ -}; - -static int cachefiles_attr_changed(struct fscache_object *_object); +static atomic_t cachefiles_object_debug_id; /* - * allocate an object record for a cookie lookup and prepare the lookup data + * Allocate a cache object record. */ -static struct fscache_object *cachefiles_alloc_object( - struct fscache_cache *_cache, - struct fscache_cookie *cookie) +static +struct cachefiles_object *cachefiles_alloc_object(struct fscache_cookie *cookie) { - struct cachefiles_lookup_data *lookup_data; + struct fscache_volume *vcookie = cookie->volume; + struct cachefiles_volume *volume = vcookie->cache_priv; struct cachefiles_object *object; - struct cachefiles_cache *cache; - struct cachefiles_xattr *auxdata; - unsigned keylen, auxlen; - void *buffer, *p; - char *key; - cache = container_of(_cache, struct cachefiles_cache, cache); + _enter("{%s},%x,", vcookie->key, cookie->debug_id); - _enter("{%s},%x,", cache->cache.identifier, cookie->debug_id); - - lookup_data = kmalloc(sizeof(*lookup_data), cachefiles_gfp); - if (!lookup_data) - goto nomem_lookup_data; - - /* create a new object record and a temporary leaf image */ - object = kmem_cache_alloc(cachefiles_object_jar, cachefiles_gfp); + object = kmem_cache_zalloc(cachefiles_object_jar, GFP_KERNEL); if (!object) - goto nomem_object; - - ASSERTCMP(object->backer, ==, NULL); + return NULL; - BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)); - atomic_set(&object->usage, 1); + refcount_set(&object->ref, 1); - fscache_object_init(&object->fscache, cookie, &cache->cache); + spin_lock_init(&object->lock); + INIT_LIST_HEAD(&object->cache_link); + object->volume = volume; + object->debug_id = atomic_inc_return(&cachefiles_object_debug_id); + object->cookie = fscache_get_cookie(cookie, fscache_cookie_get_attach_object); - object->type = cookie->def->type; - - /* get hold of the raw key - * - stick the length on the front and leave space on the back for the - * encoder - */ - buffer = kmalloc((2 + 512) + 3, cachefiles_gfp); - if (!buffer) - goto nomem_buffer; - - keylen = cookie->key_len; - if (keylen <= sizeof(cookie->inline_key)) - p = cookie->inline_key; - else - p = cookie->key; - memcpy(buffer + 2, p, keylen); - - *(uint16_t *)buffer = keylen; - ((char *)buffer)[keylen + 2] = 0; - ((char *)buffer)[keylen + 3] = 0; - ((char *)buffer)[keylen + 4] = 0; - - /* turn the raw key into something that can work with as a filename */ - key = cachefiles_cook_key(buffer, keylen + 2, object->type); - if (!key) - goto nomem_key; - - /* get hold of the auxiliary data and prepend the object type */ - auxdata = buffer; - auxlen = cookie->aux_len; - if (auxlen) { - if (auxlen <= sizeof(cookie->inline_aux)) - p = cookie->inline_aux; - else - p = cookie->aux; - memcpy(auxdata->data, p, auxlen); - } - - auxdata->len = auxlen + 1; - auxdata->type = cookie->type; - - lookup_data->auxdata = auxdata; - lookup_data->key = key; - object->lookup_data = lookup_data; - - _leave(" = %x [%p]", object->fscache.debug_id, lookup_data); - return &object->fscache; - -nomem_key: - kfree(buffer); -nomem_buffer: - BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)); - kmem_cache_free(cachefiles_object_jar, object); - fscache_object_destroyed(&cache->cache); -nomem_object: - kfree(lookup_data); -nomem_lookup_data: - _leave(" = -ENOMEM"); - return ERR_PTR(-ENOMEM); + fscache_count_object(vcookie->cache); + trace_cachefiles_ref(object->debug_id, cookie->debug_id, 1, + cachefiles_obj_new); + return object; } /* - * attempt to look up the nominated node in this cache - * - return -ETIMEDOUT to be scheduled again + * Note that an object has been seen. */ -static int cachefiles_lookup_object(struct fscache_object *_object) +void cachefiles_see_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why) { - struct cachefiles_lookup_data *lookup_data; - struct cachefiles_object *parent, *object; - struct cachefiles_cache *cache; - const struct cred *saved_cred; - int ret; - - _enter("{OBJ%x}", _object->debug_id); - - cache = container_of(_object->cache, struct cachefiles_cache, cache); - parent = container_of(_object->parent, - struct cachefiles_object, fscache); - object = container_of(_object, struct cachefiles_object, fscache); - lookup_data = object->lookup_data; - - ASSERTCMP(lookup_data, !=, NULL); - - /* look up the key, creating any missing bits */ - cachefiles_begin_secure(cache, &saved_cred); - ret = cachefiles_walk_to_object(parent, object, - lookup_data->key, - lookup_data->auxdata); - cachefiles_end_secure(cache, saved_cred); - - /* polish off by setting the attributes of non-index files */ - if (ret == 0 && - object->fscache.cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) - cachefiles_attr_changed(&object->fscache); - - if (ret < 0 && ret != -ETIMEDOUT) { - if (ret != -ENOBUFS) - pr_warn("Lookup failed error %d\n", ret); - fscache_object_lookup_error(&object->fscache); - } - - _leave(" [%d]", ret); - return ret; + trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, + refcount_read(&object->ref), why); } /* - * indication of lookup completion + * Increment the usage count on an object; */ -static void cachefiles_lookup_complete(struct fscache_object *_object) +struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why) { - struct cachefiles_object *object; - - object = container_of(_object, struct cachefiles_object, fscache); - - _enter("{OBJ%x,%p}", object->fscache.debug_id, object->lookup_data); + int r; - if (object->lookup_data) { - kfree(object->lookup_data->key); - kfree(object->lookup_data->auxdata); - kfree(object->lookup_data); - object->lookup_data = NULL; - } + __refcount_inc(&object->ref, &r); + trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, r, why); + return object; } /* - * increment the usage count on an inode object (may fail if unmounting) + * dispose of a reference to an object */ -static -struct fscache_object *cachefiles_grab_object(struct fscache_object *_object, - enum fscache_obj_ref_trace why) +void cachefiles_put_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why) { - struct cachefiles_object *object = - container_of(_object, struct cachefiles_object, fscache); - int u; + unsigned int object_debug_id = object->debug_id; + unsigned int cookie_debug_id = object->cookie->debug_id; + struct fscache_cache *cache; + bool done; + int r; + + done = __refcount_dec_and_test(&object->ref, &r); + trace_cachefiles_ref(object_debug_id, cookie_debug_id, r, why); + if (done) { + _debug("- kill object OBJ%x", object_debug_id); + + ASSERTCMP(object->file, ==, NULL); - _enter("{OBJ%x,%d}", _object->debug_id, atomic_read(&object->usage)); + kfree(object->d_name); -#ifdef CACHEFILES_DEBUG_SLAB - ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000); -#endif + cache = object->volume->cache->cache; + fscache_put_cookie(object->cookie, fscache_cookie_put_object); + object->cookie = NULL; + kmem_cache_free(cachefiles_object_jar, object); + fscache_uncount_object(cache); + } - u = atomic_inc_return(&object->usage); - trace_cachefiles_ref(object, _object->cookie, - (enum cachefiles_obj_ref_trace)why, u); - return &object->fscache; + _leave(""); } /* - * update the auxiliary data for an object object on disk + * Adjust the size of a cache file if necessary to match the DIO size. We keep + * the EOF marker a multiple of DIO blocks so that we don't fall back to doing + * non-DIO for a partial block straddling the EOF, but we also have to be + * careful of someone expanding the file and accidentally accreting the + * padding. */ -static void cachefiles_update_object(struct fscache_object *_object) +static int cachefiles_adjust_size(struct cachefiles_object *object) { - struct cachefiles_object *object; - struct cachefiles_xattr *auxdata; - struct cachefiles_cache *cache; - struct fscache_cookie *cookie; - const struct cred *saved_cred; - const void *aux; - unsigned auxlen; + struct iattr newattrs; + struct file *file = object->file; + uint64_t ni_size; + loff_t oi_size; + int ret; - _enter("{OBJ%x}", _object->debug_id); + ni_size = object->cookie->object_size; + ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE); - object = container_of(_object, struct cachefiles_object, fscache); - cache = container_of(object->fscache.cache, struct cachefiles_cache, - cache); + _enter("{OBJ%x},[%llu]", + object->debug_id, (unsigned long long) ni_size); - if (!fscache_use_cookie(_object)) { - _leave(" [relinq]"); - return; - } + if (!file) + return -ENOBUFS; - cookie = object->fscache.cookie; - auxlen = cookie->aux_len; + oi_size = i_size_read(file_inode(file)); + if (oi_size == ni_size) + return 0; - if (!auxlen) { - fscache_unuse_cookie(_object); - _leave(" [no aux]"); - return; - } + inode_lock(file_inode(file)); - auxdata = kmalloc(2 + auxlen + 3, cachefiles_gfp); - if (!auxdata) { - fscache_unuse_cookie(_object); - _leave(" [nomem]"); - return; + /* if there's an extension to a partial page at the end of the backing + * file, we need to discard the partial page so that we pick up new + * data after it */ + if (oi_size & ~PAGE_MASK && ni_size > oi_size) { + _debug("discard tail %llx", oi_size); + newattrs.ia_valid = ATTR_SIZE; + newattrs.ia_size = oi_size & PAGE_MASK; + ret = cachefiles_inject_remove_error(); + if (ret == 0) + ret = notify_change(&init_user_ns, file->f_path.dentry, + &newattrs, NULL); + if (ret < 0) + goto truncate_failed; } - aux = (auxlen <= sizeof(cookie->inline_aux)) ? - cookie->inline_aux : cookie->aux; + newattrs.ia_valid = ATTR_SIZE; + newattrs.ia_size = ni_size; + ret = cachefiles_inject_write_error(); + if (ret == 0) + ret = notify_change(&init_user_ns, file->f_path.dentry, + &newattrs, NULL); - memcpy(auxdata->data, aux, auxlen); - fscache_unuse_cookie(_object); +truncate_failed: + inode_unlock(file_inode(file)); - auxdata->len = auxlen + 1; - auxdata->type = cookie->type; + if (ret < 0) + trace_cachefiles_io_error(NULL, file_inode(file), ret, + cachefiles_trace_notify_change_error); + if (ret == -EIO) { + cachefiles_io_error_obj(object, "Size set failed"); + ret = -ENOBUFS; + } - cachefiles_begin_secure(cache, &saved_cred); - cachefiles_update_object_xattr(object, auxdata); - cachefiles_end_secure(cache, saved_cred); - kfree(auxdata); - _leave(""); + _leave(" = %d", ret); + return ret; } /* - * discard the resources pinned by an object and effect retirement if - * requested + * Attempt to look up the nominated node in this cache */ -static void cachefiles_drop_object(struct fscache_object *_object) +static bool cachefiles_lookup_cookie(struct fscache_cookie *cookie) { struct cachefiles_object *object; - struct cachefiles_cache *cache; + struct cachefiles_cache *cache = cookie->volume->cache->cache_priv; const struct cred *saved_cred; - struct inode *inode; - blkcnt_t i_blocks = 0; + bool success; - ASSERT(_object); + object = cachefiles_alloc_object(cookie); + if (!object) + goto fail; - object = container_of(_object, struct cachefiles_object, fscache); + _enter("{OBJ%x}", object->debug_id); - _enter("{OBJ%x,%d}", - object->fscache.debug_id, atomic_read(&object->usage)); + if (!cachefiles_cook_key(object)) + goto fail_put; - cache = container_of(object->fscache.cache, - struct cachefiles_cache, cache); + cookie->cache_priv = object; -#ifdef CACHEFILES_DEBUG_SLAB - ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000); -#endif + cachefiles_begin_secure(cache, &saved_cred); - /* We need to tidy the object up if we did in fact manage to open it. - * It's possible for us to get here before the object is fully - * initialised if the parent goes away or the object gets retired - * before we set it up. - */ - if (object->dentry) { - /* delete retired objects */ - if (test_bit(FSCACHE_OBJECT_RETIRED, &object->fscache.flags) && - _object != cache->cache.fsdef - ) { - _debug("- retire object OBJ%x", object->fscache.debug_id); - inode = d_backing_inode(object->dentry); - if (inode) - i_blocks = inode->i_blocks; - - cachefiles_begin_secure(cache, &saved_cred); - cachefiles_delete_object(cache, object); - cachefiles_end_secure(cache, saved_cred); - } + success = cachefiles_look_up_object(object); + if (!success) + goto fail_withdraw; - /* close the filesystem stuff attached to the object */ - if (object->backer != object->dentry) - dput(object->backer); - object->backer = NULL; - } + cachefiles_see_object(object, cachefiles_obj_see_lookup_cookie); + + spin_lock(&cache->object_list_lock); + list_add(&object->cache_link, &cache->object_list); + spin_unlock(&cache->object_list_lock); + cachefiles_adjust_size(object); - /* note that the object is now inactive */ - if (test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) - cachefiles_mark_object_inactive(cache, object, i_blocks); + cachefiles_end_secure(cache, saved_cred); + _leave(" = t"); + return true; - dput(object->dentry); - object->dentry = NULL; +fail_withdraw: + cachefiles_end_secure(cache, saved_cred); + cachefiles_see_object(object, cachefiles_obj_see_lookup_failed); + fscache_caching_failed(cookie); + _debug("failed c=%08x o=%08x", cookie->debug_id, object->debug_id); + /* The caller holds an access count on the cookie, so we need them to + * drop it before we can withdraw the object. + */ + return false; - _leave(""); +fail_put: + cachefiles_put_object(object, cachefiles_obj_put_alloc_fail); +fail: + return false; } /* - * dispose of a reference to an object + * Shorten the backing object to discard any dirty data and free up + * any unused granules. */ -void cachefiles_put_object(struct fscache_object *_object, - enum fscache_obj_ref_trace why) +static bool cachefiles_shorten_object(struct cachefiles_object *object, + struct file *file, loff_t new_size) { - struct cachefiles_object *object; - struct fscache_cache *cache; - int u; - - ASSERT(_object); - - object = container_of(_object, struct cachefiles_object, fscache); - - _enter("{OBJ%x,%d}", - object->fscache.debug_id, atomic_read(&object->usage)); - -#ifdef CACHEFILES_DEBUG_SLAB - ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000); -#endif - - ASSERTIFCMP(object->fscache.parent, - object->fscache.parent->n_children, >, 0); - - u = atomic_dec_return(&object->usage); - trace_cachefiles_ref(object, _object->cookie, - (enum cachefiles_obj_ref_trace)why, u); - ASSERTCMP(u, !=, -1); - if (u == 0) { - _debug("- kill object OBJ%x", object->fscache.debug_id); + struct cachefiles_cache *cache = object->volume->cache; + struct inode *inode = file_inode(file); + loff_t i_size, dio_size; + int ret; - ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)); - ASSERTCMP(object->fscache.parent, ==, NULL); - ASSERTCMP(object->backer, ==, NULL); - ASSERTCMP(object->dentry, ==, NULL); - ASSERTCMP(object->fscache.n_ops, ==, 0); - ASSERTCMP(object->fscache.n_children, ==, 0); + dio_size = round_up(new_size, CACHEFILES_DIO_BLOCK_SIZE); + i_size = i_size_read(inode); + + trace_cachefiles_trunc(object, inode, i_size, dio_size, + cachefiles_trunc_shrink); + ret = cachefiles_inject_remove_error(); + if (ret == 0) + ret = vfs_truncate(&file->f_path, dio_size); + if (ret < 0) { + trace_cachefiles_io_error(object, file_inode(file), ret, + cachefiles_trace_trunc_error); + cachefiles_io_error_obj(object, "Trunc-to-size failed %d", ret); + cachefiles_remove_object_xattr(cache, object, file->f_path.dentry); + return false; + } - if (object->lookup_data) { - kfree(object->lookup_data->key); - kfree(object->lookup_data->auxdata); - kfree(object->lookup_data); - object->lookup_data = NULL; + if (new_size < dio_size) { + trace_cachefiles_trunc(object, inode, dio_size, new_size, + cachefiles_trunc_dio_adjust); + ret = cachefiles_inject_write_error(); + if (ret == 0) + ret = vfs_fallocate(file, FALLOC_FL_ZERO_RANGE, + new_size, dio_size); + if (ret < 0) { + trace_cachefiles_io_error(object, file_inode(file), ret, + cachefiles_trace_fallocate_error); + cachefiles_io_error_obj(object, "Trunc-to-dio-size failed %d", ret); + cachefiles_remove_object_xattr(cache, object, file->f_path.dentry); + return false; } - - cache = object->fscache.cache; - fscache_object_destroy(&object->fscache); - kmem_cache_free(cachefiles_object_jar, object); - fscache_object_destroyed(cache); } - _leave(""); + return true; } /* - * sync a cache + * Resize the backing object. */ -static void cachefiles_sync_cache(struct fscache_cache *_cache) +static void cachefiles_resize_cookie(struct netfs_cache_resources *cres, + loff_t new_size) { - struct cachefiles_cache *cache; + struct cachefiles_object *object = cachefiles_cres_object(cres); + struct cachefiles_cache *cache = object->volume->cache; + struct fscache_cookie *cookie = object->cookie; const struct cred *saved_cred; - int ret; + struct file *file = cachefiles_cres_file(cres); + loff_t old_size = cookie->object_size; - _enter("%s", _cache->tag->name); + _enter("%llu->%llu", old_size, new_size); - cache = container_of(_cache, struct cachefiles_cache, cache); - - /* make sure all pages pinned by operations on behalf of the netfs are - * written to disc */ - cachefiles_begin_secure(cache, &saved_cred); - down_read(&cache->mnt->mnt_sb->s_umount); - ret = sync_filesystem(cache->mnt->mnt_sb); - up_read(&cache->mnt->mnt_sb->s_umount); - cachefiles_end_secure(cache, saved_cred); + if (new_size < old_size) { + cachefiles_begin_secure(cache, &saved_cred); + cachefiles_shorten_object(object, file, new_size); + cachefiles_end_secure(cache, saved_cred); + object->cookie->object_size = new_size; + return; + } - if (ret == -EIO) - cachefiles_io_error(cache, - "Attempt to sync backing fs superblock" - " returned error %d", - ret); + /* The file is being expanded. We don't need to do anything + * particularly. cookie->initial_size doesn't change and so the point + * at which we have to download before doesn't change. + */ + cookie->object_size = new_size; } /* - * check if the backing cache is updated to FS-Cache - * - called by FS-Cache when evaluates if need to invalidate the cache + * Commit changes to the object as we drop it. */ -static int cachefiles_check_consistency(struct fscache_operation *op) +static void cachefiles_commit_object(struct cachefiles_object *object, + struct cachefiles_cache *cache) { - struct cachefiles_object *object; - struct cachefiles_cache *cache; - const struct cred *saved_cred; - int ret; + bool update = false; - _enter("{OBJ%x}", op->object->debug_id); + if (test_and_clear_bit(FSCACHE_COOKIE_LOCAL_WRITE, &object->cookie->flags)) + update = true; + if (test_and_clear_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags)) + update = true; + if (update) + cachefiles_set_object_xattr(object); - object = container_of(op->object, struct cachefiles_object, fscache); - cache = container_of(object->fscache.cache, - struct cachefiles_cache, cache); + if (test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) + cachefiles_commit_tmpfile(cache, object); +} - cachefiles_begin_secure(cache, &saved_cred); - ret = cachefiles_check_auxdata(object); - cachefiles_end_secure(cache, saved_cred); +/* + * Finalise and object and close the VFS structs that we have. + */ +static void cachefiles_clean_up_object(struct cachefiles_object *object, + struct cachefiles_cache *cache) +{ + if (test_bit(FSCACHE_COOKIE_RETIRED, &object->cookie->flags)) { + if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) { + cachefiles_see_object(object, cachefiles_obj_see_clean_delete); + _debug("- inval object OBJ%x", object->debug_id); + cachefiles_delete_object(object, FSCACHE_OBJECT_WAS_RETIRED); + } else { + cachefiles_see_object(object, cachefiles_obj_see_clean_drop_tmp); + _debug("- inval object OBJ%x tmpfile", object->debug_id); + } + } else { + cachefiles_see_object(object, cachefiles_obj_see_clean_commit); + cachefiles_commit_object(object, cache); + } - _leave(" = %d", ret); - return ret; + cachefiles_unmark_inode_in_use(object, object->file); + if (object->file) { + fput(object->file); + object->file = NULL; + } } /* - * notification the attributes on an object have changed - * - called with reads/writes excluded by FS-Cache + * Withdraw caching for a cookie. */ -static int cachefiles_attr_changed(struct fscache_object *_object) +static void cachefiles_withdraw_cookie(struct fscache_cookie *cookie) { - struct cachefiles_object *object; - struct cachefiles_cache *cache; + struct cachefiles_object *object = cookie->cache_priv; + struct cachefiles_cache *cache = object->volume->cache; const struct cred *saved_cred; - struct iattr newattrs; - uint64_t ni_size; - loff_t oi_size; - int ret; - - ni_size = _object->store_limit_l; - - _enter("{OBJ%x},[%llu]", - _object->debug_id, (unsigned long long) ni_size); - - object = container_of(_object, struct cachefiles_object, fscache); - cache = container_of(object->fscache.cache, - struct cachefiles_cache, cache); - - if (ni_size == object->i_size) - return 0; - - if (!object->backer) - return -ENOBUFS; - ASSERT(d_is_reg(object->backer)); + _enter("o=%x", object->debug_id); + cachefiles_see_object(object, cachefiles_obj_see_withdraw_cookie); - fscache_set_store_limit(&object->fscache, ni_size); - - oi_size = i_size_read(d_backing_inode(object->backer)); - if (oi_size == ni_size) - return 0; - - cachefiles_begin_secure(cache, &saved_cred); - inode_lock(d_inode(object->backer)); - - /* if there's an extension to a partial page at the end of the backing - * file, we need to discard the partial page so that we pick up new - * data after it */ - if (oi_size & ~PAGE_MASK && ni_size > oi_size) { - _debug("discard tail %llx", oi_size); - newattrs.ia_valid = ATTR_SIZE; - newattrs.ia_size = oi_size & PAGE_MASK; - ret = notify_change(&init_user_ns, object->backer, &newattrs, NULL); - if (ret < 0) - goto truncate_failed; + if (!list_empty(&object->cache_link)) { + spin_lock(&cache->object_list_lock); + cachefiles_see_object(object, cachefiles_obj_see_withdrawal); + list_del_init(&object->cache_link); + spin_unlock(&cache->object_list_lock); } - newattrs.ia_valid = ATTR_SIZE; - newattrs.ia_size = ni_size; - ret = notify_change(&init_user_ns, object->backer, &newattrs, NULL); - -truncate_failed: - inode_unlock(d_inode(object->backer)); - cachefiles_end_secure(cache, saved_cred); - - if (ret == -EIO) { - fscache_set_store_limit(&object->fscache, 0); - cachefiles_io_error_obj(object, "Size set failed"); - ret = -ENOBUFS; + if (object->file) { + cachefiles_begin_secure(cache, &saved_cred); + cachefiles_clean_up_object(object, cache); + cachefiles_end_secure(cache, saved_cred); } - _leave(" = %d", ret); - return ret; + cookie->cache_priv = NULL; + cachefiles_put_object(object, cachefiles_obj_put_detach); } /* - * Invalidate an object + * Invalidate the storage associated with a cookie. */ -static void cachefiles_invalidate_object(struct fscache_operation *op) +static bool cachefiles_invalidate_cookie(struct fscache_cookie *cookie) { - struct cachefiles_object *object; - struct cachefiles_cache *cache; - const struct cred *saved_cred; - struct path path; - uint64_t ni_size; - int ret; + struct cachefiles_object *object = cookie->cache_priv; + struct file *new_file, *old_file; + bool old_tmpfile; - object = container_of(op->object, struct cachefiles_object, fscache); - cache = container_of(object->fscache.cache, - struct cachefiles_cache, cache); + _enter("o=%x,[%llu]", object->debug_id, object->cookie->object_size); - ni_size = op->object->store_limit_l; + old_tmpfile = test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags); - _enter("{OBJ%x},[%llu]", - op->object->debug_id, (unsigned long long)ni_size); + if (!object->file) { + fscache_resume_after_invalidation(cookie); + _leave(" = t [light]"); + return true; + } - if (object->backer) { - ASSERT(d_is_reg(object->backer)); + new_file = cachefiles_create_tmpfile(object); + if (IS_ERR(new_file)) + goto failed; - fscache_set_store_limit(&object->fscache, ni_size); + /* Substitute the VFS target */ + _debug("sub"); + spin_lock(&object->lock); - path.dentry = object->backer; - path.mnt = cache->mnt; + old_file = object->file; + object->file = new_file; + object->content_info = CACHEFILES_CONTENT_NO_DATA; + set_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags); + set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags); - cachefiles_begin_secure(cache, &saved_cred); - ret = vfs_truncate(&path, 0); - if (ret == 0) - ret = vfs_truncate(&path, ni_size); - cachefiles_end_secure(cache, saved_cred); + spin_unlock(&object->lock); + _debug("subbed"); + + /* Allow I/O to take place again */ + fscache_resume_after_invalidation(cookie); + + if (old_file) { + if (!old_tmpfile) { + struct cachefiles_volume *volume = object->volume; + struct dentry *fan = volume->fanout[(u8)cookie->key_hash]; - if (ret != 0) { - fscache_set_store_limit(&object->fscache, 0); - if (ret == -EIO) - cachefiles_io_error_obj(object, - "Invalidate failed"); + inode_lock_nested(d_inode(fan), I_MUTEX_PARENT); + cachefiles_bury_object(volume->cache, object, fan, + old_file->f_path.dentry, + FSCACHE_OBJECT_INVALIDATED); } + fput(old_file); } - fscache_op_complete(op, true); - _leave(""); -} + _leave(" = t"); + return true; -/* - * dissociate a cache from all the pages it was backing - */ -static void cachefiles_dissociate_pages(struct fscache_cache *cache) -{ - _enter(""); +failed: + _leave(" = f"); + return false; } const struct fscache_cache_ops cachefiles_cache_ops = { .name = "cachefiles", - .alloc_object = cachefiles_alloc_object, - .lookup_object = cachefiles_lookup_object, - .lookup_complete = cachefiles_lookup_complete, - .grab_object = cachefiles_grab_object, - .update_object = cachefiles_update_object, - .invalidate_object = cachefiles_invalidate_object, - .drop_object = cachefiles_drop_object, - .put_object = cachefiles_put_object, - .sync_cache = cachefiles_sync_cache, - .attr_changed = cachefiles_attr_changed, - .read_or_alloc_page = cachefiles_read_or_alloc_page, - .read_or_alloc_pages = cachefiles_read_or_alloc_pages, - .allocate_page = cachefiles_allocate_page, - .allocate_pages = cachefiles_allocate_pages, - .write_page = cachefiles_write_page, - .uncache_page = cachefiles_uncache_page, - .dissociate_pages = cachefiles_dissociate_pages, - .check_consistency = cachefiles_check_consistency, - .begin_read_operation = cachefiles_begin_read_operation, + .acquire_volume = cachefiles_acquire_volume, + .free_volume = cachefiles_free_volume, + .lookup_cookie = cachefiles_lookup_cookie, + .withdraw_cookie = cachefiles_withdraw_cookie, + .invalidate_cookie = cachefiles_invalidate_cookie, + .begin_operation = cachefiles_begin_operation, + .resize_cookie = cachefiles_resize_cookie, + .prepare_to_write = cachefiles_prepare_to_write, }; 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