Offering: HULK hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB5UKT
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Now every time the daemon reads an open request, it requests a new anon fd and ondemand_id. With the introduction of "restore", it is possible to read the same open request more than once, and therefore have multiple anon fd's for the same object. To avoid this, allocate a new anon fd only if no anon fd has been allocated (ondemand_id == 0) or if the previously allocated anon fd has been closed (ondemand_id == -1).
Signed-off-by: Baokun Li libaokun1@huawei.com --- fs/cachefiles/ondemand.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index c15433196a88..2cbe8a1b953f 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -22,10 +22,15 @@ static int cachefiles_ondemand_fd_release(struct inode *inode, struct cachefiles_cache *cache; void **slot; struct radix_tree_iter iter; - struct cachefiles_ondemand_info *info = object->private; - int object_id = info->ondemand_id; + struct cachefiles_ondemand_info *info; + int object_id; struct cachefiles_req *req;
+ if (!object) + return 0; + + info = object->private; + object_id = info->ondemand_id; cache = container_of(object->fscache.cache, struct cachefiles_cache, cache);
@@ -273,16 +278,27 @@ static int cachefiles_ondemand_get_fd(struct cachefiles_req *req) goto err_put_fd; }
+ spin_lock(&object->private->lock); + if (object->private->ondemand_id > 0) { + spin_unlock(&object->private->lock); + ret = -EEXIST; + file->private_data = NULL; + goto err_put_file; + } + file->f_mode |= FMODE_PWRITE | FMODE_LSEEK; fd_install(fd, file);
load = (void *)req->msg.data; load->fd = fd; object->private->ondemand_id = object_id; + spin_unlock(&object->private->lock);
cachefiles_get_unbind_pincount(cache); return 0;
+err_put_file: + fput(file); err_put_fd: put_unused_fd(fd); err_free_id: @@ -290,6 +306,12 @@ static int cachefiles_ondemand_get_fd(struct cachefiles_req *req) idr_remove(&cache->ondemand_ids, object_id); xa_unlock(&cache->ondemand_ids.idr_rt); err: + spin_lock(&req->object->private->lock); + /* Avoid marking an opened object as closed. */ + if (ret && object->private->ondemand_id <= 0) + cachefiles_ondemand_set_object_close(req->object); + spin_unlock(&req->object->private->lock); + object->fscache.cache->ops->put_object(&object->fscache, cachefiles_obj_put_ondemand_fd); return ret; @@ -381,10 +403,8 @@ ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
if (msg->opcode == CACHEFILES_OP_OPEN) { ret = cachefiles_ondemand_get_fd(req); - if (ret) { - cachefiles_ondemand_set_object_close(req->object); + if (ret) goto out; - } }
msg->msg_id = id;