[Devel] [PATCH 3/6] fuse: make fuse_direct_io() aware about AIO
Maxim V. Patlasov
MPatlasov at parallels.com
Fri Dec 14 07:20:51 PST 2012
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 at parallels.com>
---
fs/fuse/cuse.c | 6 +++--
fs/fuse/file.c | 69 +++++++++++++++++++++++++++++++++++++++---------------
fs/fuse/fuse_i.h | 2 +-
3 files changed, 55 insertions(+), 22 deletions(-)
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index 65ce10a..d890901 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -92,8 +92,9 @@ static ssize_t cuse_read(struct file *file, char __user *buf, size_t count,
{
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 @@ static ssize_t cuse_write(struct file *file, const char __user *buf,
{
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/file.c b/fs/fuse/file.c
index 8dd931f..6c2ca8a 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -595,9 +595,10 @@ static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *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;
@@ -608,6 +609,10 @@ static size_t fuse_send_read(struct fuse_req *req, struct file *file,
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;
}
@@ -628,6 +633,7 @@ static void fuse_read_update_size(struct inode *inode, loff_t size,
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;
@@ -660,7 +666,7 @@ static int fuse_readpage(struct file *file, struct page *page)
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);
@@ -862,9 +868,10 @@ static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
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;
@@ -875,6 +882,10 @@ static size_t fuse_send_write(struct fuse_req *req, struct file *file,
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;
}
@@ -898,11 +909,12 @@ static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
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;
@@ -1240,10 +1252,11 @@ static inline int fuse_iter_npages(const struct iov_iter *ii_p)
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;
@@ -1264,16 +1277,20 @@ ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
size_t nbytes = min(count, nmax);
int err = fuse_get_user_pages(req, &ii, &nbytes, write);
if (err) {
+ if (io->async)
+ fuse_put_request(fc, req);
+
res = err;
break;
}
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;
@@ -1288,13 +1305,14 @@ ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
if (nres != nbytes)
break;
if (count) {
- fuse_put_request(fc, req);
+ if (!io->async)
+ fuse_put_request(fc, req);
req = fuse_get_req(fc, fuse_iter_npages(&ii));
if (IS_ERR(req))
break;
}
}
- if (!IS_ERR(req))
+ if (!IS_ERR(req) && !io->async)
fuse_put_request(fc, req);
if (res > 0)
*ppos = pos;
@@ -1303,16 +1321,17 @@ ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
}
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->f_path.dentry->d_inode;
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);
@@ -1323,21 +1342,23 @@ static ssize_t __fuse_direct_read(struct file *file, const struct iovec *iov,
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->f_path.dentry->d_inode;
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);
}
@@ -1352,13 +1373,14 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
struct inode *inode = file->f_path.dentry->d_inode;
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;
@@ -2326,14 +2348,23 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
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 e0a5b65..91b5192 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -828,7 +828,7 @@ int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
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,
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