From 40ac7ab2d02176f8a70e37b88e41637ed97b304b Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 10 Sep 2019 15:04:08 +0200 Subject: [PATCH] fuse: simplify 'nofail' request Instead of complex games with a reserved request, just use __GFP_NOFAIL. Both calers (flush, readdir) guarantee that connection was already initialized, so no need to wait for fc->initialized. Also remove unneeded clearing of FR_BACKGROUND flag. Signed-off-by: Miklos Szeredi --- fs/fuse/dev.c | 64 ++++---------------------------------------------------- fs/fuse/file.c | 2 +- fs/fuse/fuse_i.h | 8 +------ fs/fuse/inode.c | 1 - 4 files changed, 6 insertions(+), 69 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index e865c6b..7833aee 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -243,52 +243,6 @@ struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc, EXPORT_SYMBOL_GPL(fuse_get_req_for_background); /* - * Return request in fuse_file->reserved_req. However that may - * currently be in use. If that is the case, wait for it to become - * available. - */ -static struct fuse_req *get_reserved_req(struct fuse_conn *fc, - struct file *file) -{ - struct fuse_req *req = NULL; - struct fuse_inode *fi = get_fuse_inode(file_inode(file)); - struct fuse_file *ff = file->private_data; - - do { - wait_event(fc->reserved_req_waitq, ff->reserved_req); - spin_lock(&fi->lock); - if (ff->reserved_req) { - req = ff->reserved_req; - ff->reserved_req = NULL; - req->stolen_file = get_file(file); - } - spin_unlock(&fi->lock); - } while (!req); - - return req; -} - -/* - * Put stolen request back into fuse_file->reserved_req - */ -static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req) -{ - struct file *file = req->stolen_file; - struct fuse_inode *fi = get_fuse_inode(file_inode(file)); - struct fuse_file *ff = file->private_data; - - WARN_ON(req->max_pages); - spin_lock(&fi->lock); - memset(req, 0, sizeof(*req)); - fuse_request_init(req, NULL, NULL, 0); - BUG_ON(ff->reserved_req); - ff->reserved_req = req; - wake_up_all(&fc->reserved_req_waitq); - spin_unlock(&fi->lock); - fput(file); -} - -/* * Gets a requests for a file operation, always succeeds * * This is used for sending the FLUSH request, which must get to @@ -301,25 +255,18 @@ static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req) * filesystem should not have it's own file open. If deadlock is * intentional, it can still be broken by "aborting" the filesystem. */ -struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, - struct file *file) +struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc) { struct fuse_req *req; atomic_inc(&fc->num_waiting); - wait_event(fc->blocked_waitq, fc->initialized); - /* Matches smp_wmb() in fuse_set_initialized() */ - smp_rmb(); - req = fuse_request_alloc(0); - if (!req) - req = get_reserved_req(fc, file); + req = __fuse_request_alloc(0, GFP_KERNEL | __GFP_NOFAIL); req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid()); req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid()); req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); __set_bit(FR_WAITING, &req->flags); - __clear_bit(FR_BACKGROUND, &req->flags); return req; } @@ -342,10 +289,7 @@ void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req) fuse_drop_waiting(fc); } - if (req->stolen_file) - put_reserved_req(fc, req); - else - fuse_request_free(req); + fuse_request_free(req); } } EXPORT_SYMBOL_GPL(fuse_put_request); @@ -719,7 +663,7 @@ void fuse_force_forget(struct file *file, u64 nodeid) memset(&inarg, 0, sizeof(inarg)); inarg.nlookup = 1; - req = fuse_get_req_nofail_nopages(fc, file); + req = fuse_get_req_nofail_nopages(fc); req->in.h.opcode = FUSE_FORGET; req->in.h.nodeid = nodeid; req->in.numargs = 1; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 1f90722..7d12c1d 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -432,7 +432,7 @@ static int fuse_flush(struct file *file, fl_owner_t id) if (err) return err; - req = fuse_get_req_nofail_nopages(fc, file); + req = fuse_get_req_nofail_nopages(fc); memset(&inarg, 0, sizeof(inarg)); inarg.fh = ff->fh; inarg.lock_owner = fuse_lock_owner_id(fc, id); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index a89362e..dd19939 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -435,8 +435,6 @@ struct fuse_req { /** Request completion callback */ void (*end)(struct fuse_conn *, struct fuse_req *); - /** Request is stolen from fuse_file->reserved_req */ - struct file *stolen_file; }; struct fuse_iqueue { @@ -580,9 +578,6 @@ struct fuse_conn { /** waitq for blocked connection */ wait_queue_head_t blocked_waitq; - /** waitq for reserved requests */ - wait_queue_head_t reserved_req_waitq; - /** Connection established, cleared on umount, connection abort and device release */ unsigned connected; @@ -927,8 +922,7 @@ void __fuse_get_request(struct fuse_req *req); /** * Gets a requests for a file operation, always succeeds */ -struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, - struct file *file); +struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc); /** * Decrement reference count of a request. If count goes to zero free diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 4eaea0b..2b9cc19 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -617,7 +617,6 @@ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns) refcount_set(&fc->count, 1); atomic_set(&fc->dev_count, 1); init_waitqueue_head(&fc->blocked_waitq); - init_waitqueue_head(&fc->reserved_req_waitq); fuse_iqueue_init(&fc->iq); INIT_LIST_HEAD(&fc->bg_queue); INIT_LIST_HEAD(&fc->entry); -- 2.7.4