From: Vivek Goyal <vgoyal@redhat.com>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
miklos@szeredi.hu
Cc: virtio-fs@redhat.com, vgoyal@redhat.com, stefanha@redhat.com,
dgilbert@redhat.com
Subject: [PATCH 10/13] fuse: Separate fuse device allocation and installation in fuse_conn
Date: Wed, 21 Aug 2019 13:37:39 -0400 [thread overview]
Message-ID: <20190821173742.24574-11-vgoyal@redhat.com> (raw)
In-Reply-To: <20190821173742.24574-1-vgoyal@redhat.com>
As of now fuse_dev_alloc() both allocates a fuse device and installs it
in fuse_conn list. fuse_dev_alloc() can fail if fuse_device allocation
fails.
virtio-fs needs to initialize multiple fuse devices (one per virtio
queue). It initializes one fuse device as part of call to
fuse_fill_super_common() and rest of the devices are allocated and
installed after that.
But, we can't affort to fail after calling fuse_fill_super_common() as
we don't have a way to undo all the actions done by fuse_fill_super_common().
So to avoid failures after the call to fuse_fill_super_common(),
pre-allocate all fuse devices early and install them into fuse connection
later.
This patch provides two separate helpers for fuse device allocation and
fuse device installation in fuse_conn.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
fs/fuse/cuse.c | 2 +-
fs/fuse/dev.c | 2 +-
fs/fuse/fuse_i.h | 4 +++-
fs/fuse/inode.c | 25 ++++++++++++++++++++-----
4 files changed, 25 insertions(+), 8 deletions(-)
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index 7bdab6521469..04727540bdbb 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -506,7 +506,7 @@ static int cuse_channel_open(struct inode *inode, struct file *file)
*/
fuse_conn_init(&cc->fc, file->f_cred->user_ns, &fuse_dev_fiq_ops, NULL);
- fud = fuse_dev_alloc(&cc->fc);
+ fud = fuse_dev_alloc_install(&cc->fc);
if (!fud) {
kfree(cc);
return -ENOMEM;
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index fa6794e96811..556e44fa6b20 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -2319,7 +2319,7 @@ static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
if (new->private_data)
return -EINVAL;
- fud = fuse_dev_alloc(fc);
+ fud = fuse_dev_alloc_install(fc);
if (!fud)
return -ENOMEM;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 70c1bde06293..605217552350 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1060,7 +1060,9 @@ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
*/
void fuse_conn_put(struct fuse_conn *fc);
-struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
+struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
+struct fuse_dev *fuse_dev_alloc(void);
+void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
void fuse_dev_free(struct fuse_dev *fud);
void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 226af184a402..0df885d6fa00 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1024,8 +1024,7 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
return 0;
}
-struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
-{
+struct fuse_dev *fuse_dev_alloc(void) {
struct fuse_dev *fud;
struct list_head *pq;
@@ -1040,16 +1039,32 @@ struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
}
fud->pq.processing = pq;
- fud->fc = fuse_conn_get(fc);
fuse_pqueue_init(&fud->pq);
+ return fud;
+}
+EXPORT_SYMBOL_GPL(fuse_dev_alloc);
+
+void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) {
+ fud->fc = fuse_conn_get(fc);
spin_lock(&fc->lock);
list_add_tail(&fud->entry, &fc->devices);
spin_unlock(&fc->lock);
+}
+EXPORT_SYMBOL_GPL(fuse_dev_install);
+struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc)
+{
+ struct fuse_dev *fud;
+
+ fud = fuse_dev_alloc();
+ if (!fud)
+ return NULL;
+
+ fuse_dev_install(fud, fc);
return fud;
}
-EXPORT_SYMBOL_GPL(fuse_dev_alloc);
+EXPORT_SYMBOL_GPL(fuse_dev_alloc_install);
void fuse_dev_free(struct fuse_dev *fud)
{
@@ -1119,7 +1134,7 @@ int fuse_fill_super_common(struct super_block *sb,
mount_data->fiq_priv);
fc->release = fuse_free_conn;
- fud = fuse_dev_alloc(fc);
+ fud = fuse_dev_alloc_install(fc);
if (!fud)
goto err_put_conn;
--
2.20.1
next prev parent reply other threads:[~2019-08-21 17:39 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 17:37 [PATCH v3 00/13] virtio-fs: shared file system for virtual machines Vivek Goyal
2019-08-21 17:37 ` [PATCH 01/13] fuse: delete dentry if timeout is zero Vivek Goyal
2019-08-21 17:37 ` [PATCH 02/13] fuse: Use default_file_splice_read for direct IO Vivek Goyal
2019-08-28 7:45 ` Miklos Szeredi
2019-08-28 12:27 ` Vivek Goyal
2019-08-21 17:37 ` [PATCH 03/13] fuse: export fuse_end_request() Vivek Goyal
2019-08-21 17:37 ` [PATCH 04/13] fuse: export fuse_len_args() Vivek Goyal
2019-08-21 17:37 ` [PATCH 05/13] fuse: Export fuse_send_init_request() Vivek Goyal
2019-08-21 17:37 ` [PATCH 06/13] fuse: export fuse_get_unique() Vivek Goyal
2019-08-21 17:37 ` [PATCH 07/13] Export fuse_dequeue_forget() function Vivek Goyal
2019-08-21 17:37 ` [PATCH 08/13] fuse: extract fuse_fill_super_common() Vivek Goyal
2019-08-21 17:37 ` [PATCH 09/13] fuse: add fuse_iqueue_ops callbacks Vivek Goyal
2019-08-21 17:37 ` Vivek Goyal [this message]
2019-08-21 17:37 ` [PATCH 11/13] virtio_fs: add skeleton virtio_fs.ko module Vivek Goyal
2019-08-21 17:37 ` [PATCH 12/13] virtio-fs: Do not provide abort interface in fusectl Vivek Goyal
2019-08-21 17:37 ` [PATCH 13/13] init/do_mounts.c: add virtio_fs root fs support Vivek Goyal
2019-08-29 9:28 ` [PATCH v3 00/13] virtio-fs: shared file system for virtual machines Miklos Szeredi
2019-08-29 11:58 ` Vivek Goyal
2019-08-29 12:35 ` Stefan Hajnoczi
2019-08-29 13:29 ` Vivek Goyal
2019-08-29 13:41 ` Miklos Szeredi
2019-08-29 14:31 ` Vivek Goyal
2019-08-29 14:47 ` Miklos Szeredi
2019-08-29 16:01 ` Vivek Goyal
2019-08-31 5:46 ` Miklos Szeredi
2019-09-03 8:05 ` Miklos Szeredi
2019-09-03 8:31 ` Michael S. Tsirkin
2019-09-03 9:17 ` Miklos Szeredi
2019-09-04 15:54 ` Stefan Hajnoczi
2019-09-03 14:07 ` Vivek Goyal
2019-09-03 14:12 ` Michael S. Tsirkin
2019-09-03 14:18 ` Vivek Goyal
2019-09-03 17:15 ` Michael S. Tsirkin
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