fuse: make fuse_direct_io() aware about AIO
The patch implements passing "struct fuse_io_priv *io" down the stack up to
fuse_send_read/write where it is used to submit request asynchronously.
io->async==0 designates synchronous processing.
Non-trivial part of the patch is changes in fuse_direct_io(): resources
like fuse requests and user pages cannot be released immediately in async
case.
Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index c59c097..b3aaf7b 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -92,8 +92,9 @@
{
loff_t pos = 0;
struct iovec iov = { .iov_base = buf, .iov_len = count };
+ struct fuse_io_priv io = { .async = 0, .file = file };
- return fuse_direct_io(file, &iov, 1, count, &pos, 0);
+ return fuse_direct_io(&io, &iov, 1, count, &pos, 0);
}
static ssize_t cuse_write(struct file *file, const char __user *buf,
@@ -101,12 +102,13 @@
{
loff_t pos = 0;
struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
+ struct fuse_io_priv io = { .async = 0, .file = file };
/*
* No locking or generic_write_checks(), the server is
* responsible for locking and sanity checks.
*/
- return fuse_direct_io(file, &iov, 1, count, &pos, 1);
+ return fuse_direct_io(&io, &iov, 1, count, &pos, 1);
}
static int cuse_open(struct inode *inode, struct file *file)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index be5c7e1..07bdb14 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -111,7 +111,7 @@
sigprocmask(SIG_SETMASK, oldset, NULL);
}
-static void __fuse_get_request(struct fuse_req *req)
+void __fuse_get_request(struct fuse_req *req)
{
atomic_inc(&req->count);
}
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 4002889..e207dcd 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -593,14 +593,16 @@
req->io = io;
req->end = fuse_aio_complete_req;
+ __fuse_get_request(req);
fuse_request_send_background(fc, req);
return num_bytes;
}
-static size_t fuse_send_read(struct fuse_req *req, struct file *file,
+static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
loff_t pos, size_t count, fl_owner_t owner)
{
+ struct file *file = io->file;
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
@@ -611,6 +613,10 @@
inarg->read_flags |= FUSE_READ_LOCKOWNER;
inarg->lock_owner = fuse_lock_owner_id(fc, owner);
}
+
+ if (io->async)
+ return fuse_async_req_send(fc, req, count, io);
+
fuse_request_send(fc, req);
return req->out.args[0].size;
}
@@ -631,6 +637,7 @@
static int fuse_readpage(struct file *file, struct page *page)
{
+ struct fuse_io_priv io = { .async = 0, .file = file };
struct inode *inode = page->mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req;
@@ -663,7 +670,7 @@
req->num_pages = 1;
req->pages[0] = page;
req->page_descs[0].length = count;
- num_read = fuse_send_read(req, file, pos, count, NULL);
+ num_read = fuse_send_read(req, &io, pos, count, NULL);
err = req->out.h.error;
fuse_put_request(fc, req);
@@ -873,9 +880,10 @@
req->out.args[0].value = outarg;
}
-static size_t fuse_send_write(struct fuse_req *req, struct file *file,
+static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
loff_t pos, size_t count, fl_owner_t owner)
{
+ struct file *file = io->file;
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
struct fuse_write_in *inarg = &req->misc.write.in;
@@ -886,6 +894,10 @@
inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
inarg->lock_owner = fuse_lock_owner_id(fc, owner);
}
+
+ if (io->async)
+ return fuse_async_req_send(fc, req, count, io);
+
fuse_request_send(fc, req);
return req->misc.write.out.size;
}
@@ -909,11 +921,12 @@
size_t res;
unsigned offset;
unsigned i;
+ struct fuse_io_priv io = { .async = 0, .file = file };
for (i = 0; i < req->num_pages; i++)
fuse_wait_on_page_writeback(inode, req->pages[i]->index);
- res = fuse_send_write(req, file, pos, count, NULL);
+ res = fuse_send_write(req, &io, pos, count, NULL);
offset = req->page_descs[0].offset;
count = res;
@@ -1251,10 +1264,11 @@
return min(npages, FUSE_MAX_PAGES_PER_REQ);
}
-ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
+ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
unsigned long nr_segs, size_t count, loff_t *ppos,
int write)
{
+ struct file *file = io->file;
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
size_t nmax = write ? fc->max_write : fc->max_read;
@@ -1280,11 +1294,12 @@
}
if (write)
- nres = fuse_send_write(req, file, pos, nbytes, owner);
+ nres = fuse_send_write(req, io, pos, nbytes, owner);
else
- nres = fuse_send_read(req, file, pos, nbytes, owner);
+ nres = fuse_send_read(req, io, pos, nbytes, owner);
- fuse_release_user_pages(req, !write);
+ if (!io->async)
+ fuse_release_user_pages(req, !write);
if (req->out.h.error) {
if (!res)
res = req->out.h.error;
@@ -1314,16 +1329,18 @@
}
EXPORT_SYMBOL_GPL(fuse_direct_io);
-static ssize_t __fuse_direct_read(struct file *file, const struct iovec *iov,
+static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
+ const struct iovec *iov,
unsigned long nr_segs, loff_t *ppos)
{
ssize_t res;
+ struct file *file = io->file;
struct inode *inode = file_inode(file);
if (is_bad_inode(inode))
return -EIO;
- res = fuse_direct_io(file, iov, nr_segs, iov_length(iov, nr_segs),
+ res = fuse_direct_io(io, iov, nr_segs, iov_length(iov, nr_segs),
ppos, 0);
fuse_invalidate_attr(inode);
@@ -1334,21 +1351,24 @@
static ssize_t fuse_direct_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
+ struct fuse_io_priv io = { .async = 0, .file = file };
struct iovec iov = { .iov_base = buf, .iov_len = count };
- return __fuse_direct_read(file, &iov, 1, ppos);
+ return __fuse_direct_read(&io, &iov, 1, ppos);
}
-static ssize_t __fuse_direct_write(struct file *file, const struct iovec *iov,
+static ssize_t __fuse_direct_write(struct fuse_io_priv *io,
+ const struct iovec *iov,
unsigned long nr_segs, loff_t *ppos)
{
+ struct file *file = io->file;
struct inode *inode = file_inode(file);
size_t count = iov_length(iov, nr_segs);
ssize_t res;
res = generic_write_checks(file, ppos, &count, 0);
if (!res) {
- res = fuse_direct_io(file, iov, nr_segs, count, ppos, 1);
- if (res > 0)
+ res = fuse_direct_io(io, iov, nr_segs, count, ppos, 1);
+ if (!io->async && res > 0)
fuse_write_update_size(inode, *ppos);
}
@@ -1363,13 +1383,14 @@
struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
struct inode *inode = file_inode(file);
ssize_t res;
+ struct fuse_io_priv io = { .async = 0, .file = file };
if (is_bad_inode(inode))
return -EIO;
/* Don't allow parallel writes to the same file */
mutex_lock(&inode->i_mutex);
- res = __fuse_direct_write(file, &iov, 1, ppos);
+ res = __fuse_direct_write(&io, &iov, 1, ppos);
mutex_unlock(&inode->i_mutex);
return res;
@@ -2339,14 +2360,23 @@
ssize_t ret = 0;
struct file *file = NULL;
loff_t pos = 0;
+ struct fuse_io_priv *io;
file = iocb->ki_filp;
pos = offset;
+ io = kzalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
+ if (!io)
+ return -ENOMEM;
+
+ io->file = file;
+
if (rw == WRITE)
- ret = __fuse_direct_write(file, iov, nr_segs, &pos);
+ ret = __fuse_direct_write(io, iov, nr_segs, &pos);
else
- ret = __fuse_direct_read(file, iov, nr_segs, &pos);
+ ret = __fuse_direct_read(io, iov, nr_segs, &pos);
+
+ kfree(io);
return ret;
}
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index aea0724..337169a 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -732,6 +732,11 @@
struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
unsigned npages);
+/*
+ * Increment reference count on request
+ */
+void __fuse_get_request(struct fuse_req *req);
+
/**
* Get a request, may fail with -ENOMEM,
* useful for callers who doesn't use req->pages[]
@@ -846,7 +851,7 @@
int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
bool isdir);
-ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
+ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
unsigned long nr_segs, size_t count, loff_t *ppos,
int write);
long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,