diff options
| -rw-r--r-- | fs/cachefiles/interface.c | 26 | ||||
| -rw-r--r-- | fs/cachefiles/internal.h | 1 | ||||
| -rw-r--r-- | fs/cachefiles/xattr.c | 36 |
3 files changed, 63 insertions, 0 deletions
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index d4c1206af9fc..43eb5592cdea 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -378,6 +378,31 @@ static void cachefiles_sync_cache(struct fscache_cache *_cache) } /* + * check if the backing cache is updated to FS-Cache + * - called by FS-Cache when evaluates if need to invalidate the cache + */ +static bool cachefiles_check_consistency(struct fscache_operation *op) +{ + struct cachefiles_object *object; + struct cachefiles_cache *cache; + const struct cred *saved_cred; + int ret; + + _enter("{OBJ%x}", op->object->debug_id); + + object = container_of(op->object, struct cachefiles_object, fscache); + cache = container_of(object->fscache.cache, + struct cachefiles_cache, cache); + + cachefiles_begin_secure(cache, &saved_cred); + ret = cachefiles_check_auxdata(object); + cachefiles_end_secure(cache, saved_cred); + + _leave(" = %d", ret); + return ret; +} + +/* * notification the attributes on an object have changed * - called with reads/writes excluded by FS-Cache */ @@ -522,4 +547,5 @@ const struct fscache_cache_ops cachefiles_cache_ops = { .write_page = cachefiles_write_page, .uncache_page = cachefiles_uncache_page, .dissociate_pages = cachefiles_dissociate_pages, + .check_consistency = cachefiles_check_consistency, }; diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index 49382519907a..5349473df1b1 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -235,6 +235,7 @@ extern int cachefiles_set_object_xattr(struct cachefiles_object *object, struct cachefiles_xattr *auxdata); extern int cachefiles_update_object_xattr(struct cachefiles_object *object, struct cachefiles_xattr *auxdata); +extern int cachefiles_check_auxdata(struct cachefiles_object *object); extern int cachefiles_check_object_xattr(struct cachefiles_object *object, struct cachefiles_xattr *auxdata); extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c index 2476e5162609..34c88b83e39f 100644 --- a/fs/cachefiles/xattr.c +++ b/fs/cachefiles/xattr.c @@ -157,6 +157,42 @@ int cachefiles_update_object_xattr(struct cachefiles_object *object, } /* + * check the consistency between the backing cache and the FS-Cache cookie + */ +int cachefiles_check_auxdata(struct cachefiles_object *object) +{ + struct cachefiles_xattr *auxbuf; + struct dentry *dentry = object->dentry; + unsigned int dlen; + int ret; + + ASSERT(dentry); + ASSERT(dentry->d_inode); + ASSERT(object->fscache.cookie->def->check_aux); + + auxbuf = kmalloc(sizeof(struct cachefiles_xattr) + 512, GFP_KERNEL); + if (!auxbuf) + return -ENOMEM; + + auxbuf->len = vfs_getxattr(dentry, cachefiles_xattr_cache, + &auxbuf->type, 512 + 1); + if (auxbuf->len < 1) + return -ESTALE; + + if (auxbuf->type != object->fscache.cookie->def->type) + return -ESTALE; + + dlen = auxbuf->len - 1; + ret = fscache_check_aux(&object->fscache, &auxbuf->data, dlen); + + kfree(auxbuf); + if (ret != FSCACHE_CHECKAUX_OKAY) + return -ESTALE; + + return 0; +} + +/* * check the state xattr on a cache file * - return -ESTALE if the object should be deleted */ |