diff options
| -rw-r--r-- | fs/cachefiles/Kconfig | 12 | ||||
| -rw-r--r-- | fs/cachefiles/Makefile | 1 | ||||
| -rw-r--r-- | fs/cachefiles/daemon.c | 81 | ||||
| -rw-r--r-- | fs/cachefiles/internal.h | 51 | ||||
| -rw-r--r-- | fs/cachefiles/namei.c | 16 | ||||
| -rw-r--r-- | fs/cachefiles/ondemand.c | 378 | ||||
| -rw-r--r-- | include/linux/fscache.h | 1 | ||||
| -rw-r--r-- | include/trace/events/cachefiles.h | 2 | ||||
| -rw-r--r-- | include/uapi/linux/cachefiles.h | 50 |
9 files changed, 577 insertions, 15 deletions
diff --git a/fs/cachefiles/Kconfig b/fs/cachefiles/Kconfig index 719faeeda168..8df715640a48 100644 --- a/fs/cachefiles/Kconfig +++ b/fs/cachefiles/Kconfig @@ -26,3 +26,15 @@ config CACHEFILES_ERROR_INJECTION help This permits error injection to be enabled in cachefiles whilst a cache is in service. + +config CACHEFILES_ONDEMAND + bool "Support for on-demand read" + depends on CACHEFILES + default n + help + This permits userspace to enable the cachefiles on-demand read mode. + In this mode, when a cache miss occurs, responsibility for fetching + the data lies with the cachefiles backend instead of with the netfs + and is delegated to userspace. + + If unsure, say N. diff --git a/fs/cachefiles/Makefile b/fs/cachefiles/Makefile index 16d811f1a2fa..c37a7a9af10b 100644 --- a/fs/cachefiles/Makefile +++ b/fs/cachefiles/Makefile @@ -16,5 +16,6 @@ cachefiles-y := \ xattr.o cachefiles-$(CONFIG_CACHEFILES_ERROR_INJECTION) += error_inject.o +cachefiles-$(CONFIG_CACHEFILES_ONDEMAND) += ondemand.o obj-$(CONFIG_CACHEFILES) := cachefiles.o diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c index 7ac04ee2c0a0..d5417da7f792 100644 --- a/fs/cachefiles/daemon.c +++ b/fs/cachefiles/daemon.c @@ -75,6 +75,9 @@ static const struct cachefiles_daemon_cmd cachefiles_daemon_cmds[] = { { "inuse", cachefiles_daemon_inuse }, { "secctx", cachefiles_daemon_secctx }, { "tag", cachefiles_daemon_tag }, +#ifdef CONFIG_CACHEFILES_ONDEMAND + { "copen", cachefiles_ondemand_copen }, +#endif { "", NULL } }; @@ -108,6 +111,8 @@ static int cachefiles_daemon_open(struct inode *inode, struct file *file) INIT_LIST_HEAD(&cache->volumes); INIT_LIST_HEAD(&cache->object_list); spin_lock_init(&cache->object_list_lock); + xa_init_flags(&cache->reqs, XA_FLAGS_ALLOC); + xa_init_flags(&cache->ondemand_ids, XA_FLAGS_ALLOC1); /* set default caching limits * - limit at 1% free space and/or free files @@ -126,6 +131,39 @@ static int cachefiles_daemon_open(struct inode *inode, struct file *file) return 0; } +static void cachefiles_flush_reqs(struct cachefiles_cache *cache) +{ + struct xarray *xa = &cache->reqs; + struct cachefiles_req *req; + unsigned long index; + + /* + * Make sure the following two operations won't be reordered. + * 1) set CACHEFILES_DEAD bit + * 2) flush requests in the xarray + * Otherwise the request may be enqueued after xarray has been + * flushed, leaving the orphan request never being completed. + * + * CPU 1 CPU 2 + * ===== ===== + * flush requests in the xarray + * test CACHEFILES_DEAD bit + * enqueue the request + * set CACHEFILES_DEAD bit + */ + smp_mb(); + + xa_lock(xa); + xa_for_each(xa, index, req) { + req->error = -EIO; + complete(&req->done); + } + xa_unlock(xa); + + xa_destroy(&cache->reqs); + xa_destroy(&cache->ondemand_ids); +} + /* * Release a cache. */ @@ -139,6 +177,8 @@ static int cachefiles_daemon_release(struct inode *inode, struct file *file) set_bit(CACHEFILES_DEAD, &cache->flags); + if (cachefiles_in_ondemand_mode(cache)) + cachefiles_flush_reqs(cache); cachefiles_daemon_unbind(cache); /* clean up the control file interface */ @@ -152,23 +192,14 @@ static int cachefiles_daemon_release(struct inode *inode, struct file *file) return 0; } -/* - * Read the cache state. - */ -static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer, - size_t buflen, loff_t *pos) +static ssize_t cachefiles_do_daemon_read(struct cachefiles_cache *cache, + char __user *_buffer, size_t buflen) { - struct cachefiles_cache *cache = file->private_data; unsigned long long b_released; unsigned f_released; char buffer[256]; int n; - //_enter(",,%zu,", buflen); - - if (!test_bit(CACHEFILES_READY, &cache->flags)) - return 0; - /* check how much space the cache has */ cachefiles_has_space(cache, 0, 0, cachefiles_has_space_check); @@ -207,6 +238,25 @@ static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer, } /* + * Read the cache state. + */ +static ssize_t cachefiles_daemon_read(struct file *file, char __user *_buffer, + size_t buflen, loff_t *pos) +{ + struct cachefiles_cache *cache = file->private_data; + + //_enter(",,%zu,", buflen); + + if (!test_bit(CACHEFILES_READY, &cache->flags)) + return 0; + + if (cachefiles_in_ondemand_mode(cache)) + return cachefiles_ondemand_daemon_read(cache, _buffer, buflen); + else + return cachefiles_do_daemon_read(cache, _buffer, buflen); +} + +/* * Take a command from cachefilesd, parse it and act on it. */ static ssize_t cachefiles_daemon_write(struct file *file, @@ -297,8 +347,13 @@ static __poll_t cachefiles_daemon_poll(struct file *file, poll_wait(file, &cache->daemon_pollwq, poll); mask = 0; - if (test_bit(CACHEFILES_STATE_CHANGED, &cache->flags)) - mask |= EPOLLIN; + if (cachefiles_in_ondemand_mode(cache)) { + if (!xa_empty(&cache->reqs)) + mask |= EPOLLIN; + } else { + if (test_bit(CACHEFILES_STATE_CHANGED, &cache->flags)) + mask |= EPOLLIN; + } if (test_bit(CACHEFILES_CULLING, &cache->flags)) mask |= EPOLLOUT; diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index e80673d0ab97..4f5150a96849 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -15,6 +15,8 @@ #include <linux/fscache-cache.h> #include <linux/cred.h> #include <linux/security.h> +#include <linux/xarray.h> +#include <linux/cachefiles.h> #define CACHEFILES_DIO_BLOCK_SIZE 4096 @@ -58,8 +60,13 @@ struct cachefiles_object { enum cachefiles_content content_info:8; /* Info about content presence */ unsigned long flags; #define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */ +#ifdef CONFIG_CACHEFILES_ONDEMAND + int ondemand_id; +#endif }; +#define CACHEFILES_ONDEMAND_ID_CLOSED -1 + /* * Cache files cache definition */ @@ -98,11 +105,30 @@ struct cachefiles_cache { #define CACHEFILES_DEAD 1 /* T if cache dead */ #define CACHEFILES_CULLING 2 /* T if cull engaged */ #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ +#define CACHEFILES_ONDEMAND_MODE 4 /* T if in on-demand read mode */ char *rootdirname; /* name of cache root directory */ char *secctx; /* LSM security context */ char *tag; /* cache binding tag */ + struct xarray reqs; /* xarray of pending on-demand requests */ + struct xarray ondemand_ids; /* xarray for ondemand_id allocation */ + u32 ondemand_id_next; }; +static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache) +{ + return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) && + test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags); +} + +struct cachefiles_req { + struct cachefiles_object *object; + struct completion done; + int error; + struct cachefiles_msg msg; +}; + +#define CACHEFILES_REQ_NEW XA_MARK_1 + #include <trace/events/cachefiles.h> static inline @@ -251,6 +277,31 @@ extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, struct cachefiles_object *object); /* + * ondemand.c + */ +#ifdef CONFIG_CACHEFILES_ONDEMAND +extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, + char __user *_buffer, size_t buflen); + +extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache, + char *args); + +extern int cachefiles_ondemand_init_object(struct cachefiles_object *object); + +#else +static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, + char __user *_buffer, size_t buflen) +{ + return -EOPNOTSUPP; +} + +static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object) +{ + return 0; +} +#endif + +/* * security.c */ extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index ca9f3e4ec4b3..facf2ebe464b 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -452,10 +452,9 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object) struct dentry *fan = volume->fanout[(u8)object->cookie->key_hash]; struct file *file; struct path path; - uint64_t ni_size = object->cookie->object_size; + uint64_t ni_size; long ret; - ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE); cachefiles_begin_secure(cache, &saved_cred); @@ -481,6 +480,15 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object) goto out_dput; } + ret = cachefiles_ondemand_init_object(object); + if (ret < 0) { + file = ERR_PTR(ret); + goto out_unuse; + } + + ni_size = object->cookie->object_size; + ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE); + if (ni_size > 0) { trace_cachefiles_trunc(object, d_backing_inode(path.dentry), 0, ni_size, cachefiles_trunc_expand_tmpfile); @@ -586,6 +594,10 @@ static bool cachefiles_open_file(struct cachefiles_object *object, } _debug("file -> %pd positive", dentry); + ret = cachefiles_ondemand_init_object(object); + if (ret < 0) + goto error_fput; + ret = cachefiles_check_auxdata(object, file); if (ret < 0) goto check_failed; diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c new file mode 100644 index 000000000000..64fc312b16d3 --- /dev/null +++ b/fs/cachefiles/ondemand.c @@ -0,0 +1,378 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <linux/fdtable.h> +#include <linux/anon_inodes.h> +#include <linux/uio.h> +#include "internal.h" + +static int cachefiles_ondemand_fd_release(struct inode *inode, + struct file *file) +{ + struct cachefiles_object *object = file->private_data; + struct cachefiles_cache *cache = object->volume->cache; + int object_id = object->ondemand_id; + + object->ondemand_id = CACHEFILES_ONDEMAND_ID_CLOSED; + xa_erase(&cache->ondemand_ids, object_id); + cachefiles_put_object(object, cachefiles_obj_put_ondemand_fd); + return 0; +} + +static ssize_t cachefiles_ondemand_fd_write_iter(struct kiocb *kiocb, + struct iov_iter *iter) +{ + struct cachefiles_object *object = kiocb->ki_filp->private_data; + struct cachefiles_cache *cache = object->volume->cache; + struct file *file = object->file; + size_t len = iter->count; + loff_t pos = kiocb->ki_pos; + const struct cred *saved_cred; + int ret; + + if (!file) + return -ENOBUFS; + + cachefiles_begin_secure(cache, &saved_cred); + ret = __cachefiles_prepare_write(object, file, &pos, &len, true); + cachefiles_end_secure(cache, saved_cred); + if (ret < 0) + return ret; + + ret = __cachefiles_write(object, file, pos, iter, NULL, NULL); + if (!ret) + ret = len; + + return ret; +} + +static loff_t cachefiles_ondemand_fd_llseek(struct file *filp, loff_t pos, + int whence) +{ + struct cachefiles_object *object = filp->private_data; + struct file *file = object->file; + + if (!file) + return -ENOBUFS; + + return vfs_llseek(file, pos, whence); +} + +static const struct file_operations cachefiles_ondemand_fd_fops = { + .owner = THIS_MODULE, + .release = cachefiles_ondemand_fd_release, + .write_iter = cachefiles_ondemand_fd_write_iter, + .llseek = cachefiles_ondemand_fd_llseek, +}; + +/* + * OPEN request Completion (copen) + * - command: "copen <id>,<cache_size>" + * <cache_size> indicates the object size if >=0, error code if negative + */ +int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args) +{ + struct cachefiles_req *req; + struct fscache_cookie *cookie; + char *pid, *psize; + unsigned long id; + long size; + int ret; + + if (!test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags)) + return -EOPNOTSUPP; + + if (!*args) { + pr_err("Empty id specified\n"); + return -EINVAL; + } + + pid = args; + psize = strchr(args, ','); + if (!psize) { + pr_err("Cache size is not specified\n"); + return -EINVAL; + } + + *psize = 0; + psize++; + + ret = kstrtoul(pid, 0, &id); + if (ret) + return ret; + + req = xa_erase(&cache->reqs, id); + if (!req) + return -EINVAL; + + /* fail OPEN request if copen format is invalid */ + ret = kstrtol(psize, 0, &size); + if (ret) { + req->error = ret; + goto out; + } + + /* fail OPEN request if daemon reports an error */ + if (size < 0) { + if (!IS_ERR_VALUE(size)) + size = -EINVAL; + req->error = size; + goto out; + } + + cookie = req->object->cookie; + cookie->object_size = size; + if (size) + clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags); + else + set_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags); + +out: + complete(&req->done); + return ret; +} + +static int cachefiles_ondemand_get_fd(struct cachefiles_req *req) +{ + struct cachefiles_object *object; + struct cachefiles_cache *cache; + struct cachefiles_open *load; + struct file *file; + u32 object_id; + int ret, fd; + + object = cachefiles_grab_object(req->object, + cachefiles_obj_get_ondemand_fd); + cache = object->volume->cache; + + ret = xa_alloc_cyclic(&cache->ondemand_ids, &object_id, NULL, + XA_LIMIT(1, INT_MAX), + &cache->ondemand_id_next, GFP_KERNEL); + if (ret < 0) + goto err; + + fd = get_unused_fd_flags(O_WRONLY); + if (fd < 0) { + ret = fd; + goto err_free_id; + } + + file = anon_inode_getfile("[cachefiles]", &cachefiles_ondemand_fd_fops, + object, O_WRONLY); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto err_put_fd; + } + + file->f_mode |= FMODE_PWRITE | FMODE_LSEEK; + fd_install(fd, file); + + load = (void *)req->msg.data; + load->fd = fd; + req->msg.object_id = object_id; + object->ondemand_id = object_id; + return 0; + +err_put_fd: + put_unused_fd(fd); +err_free_id: + xa_erase(&cache->ondemand_ids, object_id); +err: + cachefiles_put_object(object, cachefiles_obj_put_ondemand_fd); + return ret; +} + +ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, + char __user *_buffer, size_t buflen) +{ + struct cachefiles_req *req; + struct cachefiles_msg *msg; + unsigned long id = 0; + size_t n; + int ret = 0; + XA_STATE(xas, &cache->reqs, 0); + + /* + * Search for a request that has not ever been processed, to prevent + * requests from being processed repeatedly. + */ + xa_lock(&cache->reqs); + req = xas_find_marked(&xas, UINT_MAX, CACHEFILES_REQ_NEW); + if (!req) { + xa_unlock(&cache->reqs); + return 0; + } + + msg = &req->msg; + n = msg->len; + + if (n > buflen) { + xa_unlock(&cache->reqs); + return -EMSGSIZE; + } + + xas_clear_mark(&xas, CACHEFILES_REQ_NEW); + xa_unlock(&cache->reqs); + + id = xas.xa_index; + msg->msg_id = id; + + if (msg->opcode == CACHEFILES_OP_OPEN) { + ret = cachefiles_ondemand_get_fd(req); + if (ret) + goto error; + } + + if (copy_to_user(_buffer, msg, n) != 0) { + ret = -EFAULT; + goto err_put_fd; + } + + return n; + +err_put_fd: + if (msg->opcode == CACHEFILES_OP_OPEN) + close_fd(((struct cachefiles_open *)msg->data)->fd); +error: + xa_erase(&cache->reqs, id); + req->error = ret; + complete(&req->done); + return ret; +} + +typedef int (*init_req_fn)(struct cachefiles_req *req, void *private); + +static int cachefiles_ondemand_send_req(struct cachefiles_object *object, + enum cachefiles_opcode opcode, + size_t data_len, + init_req_fn init_req, + void *private) +{ + struct cachefiles_cache *cache = object->volume->cache; + struct cachefiles_req *req; + XA_STATE(xas, &cache->reqs, 0); + int ret; + + if (!test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags)) + return 0; + + if (test_bit(CACHEFILES_DEAD, &cache->flags)) + return -EIO; + + req = kzalloc(sizeof(*req) + data_len, GFP_KERNEL); + if (!req) + return -ENOMEM; + + req->object = object; + init_completion(&req->done); + req->msg.opcode = opcode; + req->msg.len = sizeof(struct cachefiles_msg) + data_len; + + ret = init_req(req, private); + if (ret) + goto out; + + do { + /* + * Stop enqueuing the request when daemon is dying. The + * following two operations need to be atomic as a whole. + * 1) check cache state, and + * 2) enqueue request if cache is alive. + * Otherwise the request may be enqueued after xarray has been + * flushed, leaving the orphan request never being completed. + * + * CPU 1 CPU 2 + * ===== ===== + * test CACHEFILES_DEAD bit + * set CACHEFILES_DEAD bit + * flush requests in the xarray + * enqueue the request + */ + xas_lock(&xas); + + if (test_bit(CACHEFILES_DEAD, &cache->flags)) { + xas_unlock(&xas); + ret = -EIO; + goto out; + } + + /* coupled with the barrier in cachefiles_flush_reqs() */ + smp_mb(); + + xas.xa_index = 0; + xas_find_marked(&xas, UINT_MAX, XA_FREE_MARK); + if (xas.xa_node == XAS_RESTART) + xas_set_err(&xas, -EBUSY); + xas_store(&xas, req); + xas_clear_mark(&xas, XA_FREE_MARK); + xas_set_mark(&xas, CACHEFILES_REQ_NEW); + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); + + ret = xas_error(&xas); + if (ret) + goto out; + + wake_up_all(&cache->daemon_pollwq); + wait_for_completion(&req->done); + ret = req->error; +out: + kfree(req); + return ret; +} + +static int cachefiles_ondemand_init_open_req(struct cachefiles_req *req, + void *private) +{ + struct cachefiles_object *object = req->object; + struct fscache_cookie *cookie = object->cookie; + struct fscache_volume *volume = object->volume->vcookie; + struct cachefiles_open *load = (void *)req->msg.data; + size_t volume_key_size, cookie_key_size; + void *volume_key, *cookie_key; + + /* + * Volume key is a NUL-terminated string. key[0] stores strlen() of the + * string, followed by the content of the string (excluding '\0'). + */ + volume_key_size = volume->key[0] + 1; + volume_key = volume->key + 1; + + /* Cookie key is binary data, which is netfs specific. */ + cookie_key_size = cookie->key_len; + cookie_key = fscache_get_key(cookie); + + if (!(object->cookie->advice & FSCACHE_ADV_WANT_CACHE_SIZE)) { + pr_err("WANT_CACHE_SIZE is needed for on-demand mode\n"); + return -EINVAL; + } + + load->volume_key_size = volume_key_size; + load->cookie_key_size = cookie_key_size; + memcpy(load->data, volume_key, volume_key_size); + memcpy(load->data + volume_key_size, cookie_key, cookie_key_size); + + return 0; +} + +int cachefiles_ondemand_init_object(struct cachefiles_object *object) +{ + struct fscache_cookie *cookie = object->cookie; + struct fscache_volume *volume = object->volume->vcookie; + size_t volume_key_size, cookie_key_size, data_len; + + /* + * CacheFiles will firstly check the cache file under the root cache + * directory. If the coherency check failed, it will fallback to + * creating a new tmpfile as the cache file. Reuse the previously + * allocated object ID if any. + */ + if (object->ondemand_id > 0) + return 0; + + volume_key_size = volume->key[0] + 1; + cookie_key_size = cookie->key_len; + data_len = sizeof(struct cachefiles_open) + + volume_key_size + cookie_key_size; + + return cachefiles_ondemand_send_req(object, CACHEFILES_OP_OPEN, + data_len, cachefiles_ondemand_init_open_req, NULL); +} diff --git a/include/linux/fscache.h b/include/linux/fscache.h index e25539072463..72585c9729a2 100644 --- a/include/linux/fscache.h +++ b/include/linux/fscache.h @@ -39,6 +39,7 @@ struct fscache_cookie; #define FSCACHE_ADV_SINGLE_CHUNK 0x01 /* The object is a single chunk of data */ #define FSCACHE_ADV_WRITE_CACHE 0x00 /* Do cache if written to locally */ #define FSCACHE_ADV_WRITE_NOCACHE 0x02 /* Don't cache if written to locally */ +#define FSCACHE_ADV_WANT_CACHE_SIZE 0x04 /* Retrieve cache size at runtime */ #define FSCACHE_INVAL_DIO_WRITE 0x01 /* Invalidate due to DIO write */ diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h index 311c14a20e70..93df9391bd7f 100644 --- a/include/trace/events/cachefiles.h +++ b/include/trace/events/cachefiles.h @@ -31,6 +31,8 @@ enum cachefiles_obj_ref_trace { cachefiles_obj_see_lookup_failed, cachefiles_obj_see_withdraw_cookie, cachefiles_obj_see_withdrawal, + cachefiles_obj_get_ondemand_fd, + cachefiles_obj_put_ondemand_fd, }; enum fscache_why_object_killed { diff --git a/include/uapi/linux/cachefiles.h b/include/uapi/linux/cachefiles.h new file mode 100644 index 000000000000..521f2fe4fe9c --- /dev/null +++ b/include/uapi/linux/cachefiles.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _LINUX_CACHEFILES_H +#define _LINUX_CACHEFILES_H + +#include <linux/types.h> + +/* + * Fscache ensures that the maximum length of cookie key is 255. The volume key + * is controlled by netfs, and generally no bigger than 255. + */ +#define CACHEFILES_MSG_MAX_SIZE 1024 + +enum cachefiles_opcode { + CACHEFILES_OP_OPEN, +}; + +/* + * Message Header + * + * @msg_id a unique ID identifying this message + * @opcode message type, CACHEFILE_OP_* + * @len message length, including message header and following data + * @object_id a unique ID identifying a cache file + * @data message type specific payload + */ +struct cachefiles_msg { + __u32 msg_id; + __u32 opcode; + __u32 len; + __u32 object_id; + __u8 data[]; +}; + +/* + * @data contains the volume_key followed directly by the cookie_key. volume_key + * is a NUL-terminated string; @volume_key_size indicates the size of the volume + * key in bytes. cookie_key is binary data, which is netfs specific; + * @cookie_key_size indicates the size of the cookie key in bytes. + * + * @fd identifies an anon_fd referring to the cache file. + */ +struct cachefiles_open { + __u32 volume_key_size; + __u32 cookie_key_size; + __u32 fd; + __u32 flags; + __u8 data[]; +}; + +#endif |