Backport from ml:
commit cc080e9e9be16ccf26135d366d7d2b65209f1d56
Author: Miklos Szeredi <[email protected]>
Date: Wed Jul 1 16:26:08 2015 +0200
fuse: introduce per-instance fuse_dev structure
Allow fuse device clones to refer to be distinguished. This patch just
adds the infrastructure by associating a separate "struct fuse_dev" with
each clone.
Signed-off-by: Miklos Szeredi <[email protected]>
Reviewed-by: Ashish Samant <[email protected]>
Signed-off-by: Maxim Patlasov <[email protected]>
---
fs/fuse/cuse.c | 14 ++++++++---
fs/fuse/dev.c | 70 ++++++++++++++++++++++++++++++++----------------------
fs/fuse/fuse_i.h | 17 +++++++++++++
fs/fuse/inode.c | 47 ++++++++++++++++++++++++++++++++++--
4 files changed, 114 insertions(+), 34 deletions(-)
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index 474be9c..9935d02 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -494,6 +494,7 @@ static void cuse_fc_release(struct fuse_conn *fc)
*/
static int cuse_channel_open(struct inode *inode, struct file *file)
{
+ struct fuse_dev *fud;
struct cuse_conn *cc;
int rc;
@@ -504,16 +505,22 @@ static int cuse_channel_open(struct inode *inode, struct
file *file)
fuse_conn_init(&cc->fc);
+ fud = fuse_dev_alloc(&cc->fc);
+ if (!fud) {
+ kfree(cc);
+ return -ENOMEM;
+ }
+
INIT_LIST_HEAD(&cc->list);
cc->fc.release = cuse_fc_release;
cc->fc.initialized = 1;
rc = cuse_send_init(cc);
if (rc) {
- fuse_conn_put(&cc->fc);
+ fuse_dev_free(fud);
return rc;
}
- file->private_data = &cc->fc; /* channel owns base reference to cc */
+ file->private_data = fud;
return 0;
}
@@ -531,7 +538,8 @@ static int cuse_channel_open(struct inode *inode, struct
file *file)
*/
static int cuse_channel_release(struct inode *inode, struct file *file)
{
- struct cuse_conn *cc = fc_to_cc(file->private_data);
+ struct fuse_dev *fud = file->private_data;
+ struct cuse_conn *cc = fc_to_cc(fud->fc);
int rc;
/* remove from the conntbl, no more access from this point on */
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index c2aac08..71d2841 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -27,13 +27,13 @@ MODULE_ALIAS("devname:fuse");
static struct kmem_cache *fuse_req_cachep;
extern struct workqueue_struct *fuse_fput_wq;
-static struct fuse_conn *fuse_get_conn(struct file *file)
+static struct fuse_dev *fuse_get_dev(struct file *file)
{
/*
* Lockless access is OK, because file->private data is set
* once during mount and is valid until the file is released.
*/
- return file->private_data;
+ return ACCESS_ONCE(file->private_data);
}
static void fuse_request_init(struct fuse_req *req, struct page **pages,
@@ -1304,13 +1304,14 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const
struct iovec *iov,
{
struct fuse_copy_state cs;
struct file *file = iocb->ki_filp;
- struct fuse_conn *fc = fuse_get_conn(file);
- if (!fc)
+ struct fuse_dev *fud = fuse_get_dev(file);
+
+ if (!fud)
return -EPERM;
fuse_copy_init(&cs, 1, iov, nr_segs);
- return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
+ return fuse_dev_do_read(fud->fc, file, &cs, iov_length(iov, nr_segs));
}
static int fuse_dev_pipe_buf_steal(struct pipe_inode_info *pipe,
@@ -1338,8 +1339,9 @@ static ssize_t fuse_dev_splice_read(struct file *in,
loff_t *ppos,
int do_wakeup = 0;
struct pipe_buffer *bufs;
struct fuse_copy_state cs;
- struct fuse_conn *fc = fuse_get_conn(in);
- if (!fc)
+ struct fuse_dev *fud = fuse_get_dev(in);
+
+ if (!fud)
return -EPERM;
bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
@@ -1349,7 +1351,7 @@ static ssize_t fuse_dev_splice_read(struct file *in,
loff_t *ppos,
fuse_copy_init(&cs, 1, NULL, 0);
cs.pipebufs = bufs;
cs.pipe = pipe;
- ret = fuse_dev_do_read(fc, in, &cs, len);
+ ret = fuse_dev_do_read(fud->fc, in, &cs, len);
if (ret < 0)
goto out;
@@ -1953,13 +1955,14 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const
struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct fuse_copy_state cs;
- struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
- if (!fc)
+ struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
+
+ if (!fud)
return -EPERM;
fuse_copy_init(&cs, 0, iov, nr_segs);
- return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
+ return fuse_dev_do_write(fud->fc, &cs, iov_length(iov, nr_segs));
}
static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
@@ -1970,12 +1973,12 @@ static ssize_t fuse_dev_splice_write(struct
pipe_inode_info *pipe,
unsigned idx;
struct pipe_buffer *bufs;
struct fuse_copy_state cs;
- struct fuse_conn *fc;
+ struct fuse_dev *fud;
size_t rem;
ssize_t ret;
- fc = fuse_get_conn(out);
- if (!fc)
+ fud = fuse_get_dev(out);
+ if (!fud)
return -EPERM;
bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
@@ -2029,7 +2032,7 @@ static ssize_t fuse_dev_splice_write(struct
pipe_inode_info *pipe,
if (flags & SPLICE_F_MOVE)
cs.move_pages = 1;
- ret = fuse_dev_do_write(fc, &cs, len);
+ ret = fuse_dev_do_write(fud->fc, &cs, len);
for (idx = 0; idx < nbuf; idx++) {
struct pipe_buffer *buf = &bufs[idx];
@@ -2044,11 +2047,12 @@ static unsigned fuse_dev_poll(struct file *file,
poll_table *wait)
{
unsigned mask = POLLOUT | POLLWRNORM;
struct fuse_iqueue *fiq;
- struct fuse_conn *fc = fuse_get_conn(file);
- if (!fc)
+ struct fuse_dev *fud = fuse_get_dev(file);
+
+ if (!fud)
return POLLERR;
- fiq = &fc->iq;
+ fiq = &fud->fc->iq;
poll_wait(file, &fiq->waitq, wait);
spin_lock(&fiq->waitq.lock);
@@ -2170,12 +2174,15 @@ EXPORT_SYMBOL_GPL(fuse_abort_conn);
int fuse_dev_release(struct inode *inode, struct file *file)
{
- struct fuse_conn *fc = fuse_get_conn(file);
- if (fc) {
+ struct fuse_dev *fud = fuse_get_dev(file);
+
+ if (fud) {
+ struct fuse_conn *fc = fud->fc;
+
WARN_ON(!list_empty(&fc->pq.io));
WARN_ON(fc->iq.fasync != NULL);
fuse_abort_conn(fc);
- fuse_conn_put(fc);
+ fuse_dev_free(fud);
}
return 0;
@@ -2184,20 +2191,27 @@ EXPORT_SYMBOL_GPL(fuse_dev_release);
static int fuse_dev_fasync(int fd, struct file *file, int on)
{
- struct fuse_conn *fc = fuse_get_conn(file);
- if (!fc)
+ struct fuse_dev *fud = fuse_get_dev(file);
+
+ if (!fud)
return -EPERM;
/* No locking - fasync_helper does its own locking */
- return fasync_helper(fd, file, on, &fc->iq.fasync);
+ return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
}
static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
{
+ struct fuse_dev *fud;
+
if (new->private_data)
return -EINVAL;
- new->private_data = fuse_conn_get(fc);
+ fud = fuse_dev_alloc(fc);
+ if (!fud)
+ return -ENOMEM;
+
+ new->private_data = fud;
return 0;
}
@@ -2216,11 +2230,11 @@ static long fuse_dev_ioctl(struct file *file, unsigned
int cmd,
err = -EINVAL;
if (old) {
- struct fuse_conn *fc = fuse_get_conn(old);
+ struct fuse_dev *fud = fuse_get_dev(old);
- if (fc) {
+ if (fud) {
mutex_lock(&fuse_mutex);
- err = fuse_device_clone(fc, file);
+ err = fuse_device_clone(fud->fc, file);
mutex_unlock(&fuse_mutex);
}
fput(old);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index ab3c1d3..128d6f2 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -451,6 +451,17 @@ struct fuse_pqueue {
};
/**
+ * Fuse device instance
+ */
+struct fuse_dev {
+ /** Fuse connection for this device */
+ struct fuse_conn *fc;
+
+ /** list entry on fc->devices */
+ struct list_head entry;
+};
+
+/**
* A Fuse connection.
*
* This structure is created, when the filesystem is mounted, and is
@@ -668,6 +679,9 @@ struct fuse_conn {
struct rw_semaphore killsb;
struct list_head conn_files;
+
+ /** List of device instances belonging to this connection */
+ struct list_head devices;
};
static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
@@ -888,6 +902,9 @@ void fuse_conn_init(struct fuse_conn *fc);
*/
void fuse_conn_put(struct fuse_conn *fc);
+struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
+void fuse_dev_free(struct fuse_dev *fud);
+
/**
* Add connection to control filesystem
*/
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index c9bbd56..a40461d 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -720,6 +720,7 @@ void fuse_conn_init(struct fuse_conn *fc)
INIT_LIST_HEAD(&fc->bg_queue);
INIT_LIST_HEAD(&fc->entry);
INIT_LIST_HEAD(&fc->conn_files);
+ INIT_LIST_HEAD(&fc->devices);
atomic_set(&fc->num_waiting, 0);
fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
@@ -1062,6 +1063,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct
fuse_req *req)
static void fuse_free_conn(struct fuse_conn *fc)
{
+ WARN_ON(!list_empty(&fc->devices));
kfree(fc);
}
@@ -1113,8 +1115,41 @@ 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 *fud;
+
+ fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
+ if (fud) {
+ fud->fc = fuse_conn_get(fc);
+
+ spin_lock(&fc->lock);
+ list_add_tail(&fud->entry, &fc->devices);
+ spin_unlock(&fc->lock);
+ }
+
+ return fud;
+}
+EXPORT_SYMBOL_GPL(fuse_dev_alloc);
+
+void fuse_dev_free(struct fuse_dev *fud)
+{
+ struct fuse_conn *fc = fud->fc;
+
+ if (fc) {
+ spin_lock(&fc->lock);
+ list_del(&fud->entry);
+ spin_unlock(&fc->lock);
+
+ fuse_conn_put(fc);
+ }
+ kfree(fud);
+}
+EXPORT_SYMBOL_GPL(fuse_dev_free);
+
static int fuse_fill_super(struct super_block *sb, void *data, int silent)
{
+ struct fuse_dev *fud;
struct fuse_conn *fc;
struct inode *root;
struct fuse_mount_data d;
@@ -1166,11 +1201,15 @@ static int fuse_fill_super(struct super_block *sb, void
*data, int silent)
fuse_conn_init(fc);
fc->release = fuse_free_conn;
+ fud = fuse_dev_alloc(fc);
+ if (!fud)
+ goto err_put_conn;
+
fc->dev = sb->s_dev;
fc->sb = sb;
err = fuse_bdi_init(fc, sb);
if (err)
- goto err_put_conn;
+ goto err_dev_free;
sb->s_bdi = &fc->bdi;
@@ -1192,7 +1231,7 @@ static int fuse_fill_super(struct super_block *sb, void
*data, int silent)
root = fuse_get_root_inode(sb, d.rootmode);
root_dentry = d_make_root(root);
if (!root_dentry)
- goto err_put_conn;
+ goto err_dev_free;
/* only now - we want root dentry with NULL ->d_op */
sb->s_d_op = &fuse_dentry_operations;
@@ -1218,7 +1257,7 @@ static int fuse_fill_super(struct super_block *sb, void
*data, int silent)
list_add_tail(&fc->entry, &fuse_conn_list);
sb->s_root = root_dentry;
- file->private_data = fuse_conn_get(fc);
+ file->private_data = fud;
mutex_unlock(&fuse_mutex);
/*
* atomic_dec_and_test() in fput() provides the necessary
@@ -1237,6 +1276,8 @@ static int fuse_fill_super(struct super_block *sb, void
*data, int silent)
fuse_request_free(init_req);
err_put_root:
dput(root_dentry);
+ err_dev_free:
+ fuse_dev_free(fud);
err_put_conn:
fuse_bdi_destroy(fc);
fuse_conn_put(fc);
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