[Devel] [PATCH 3/6] fuse: make fuse_direct_io() aware about AIO
Maxim V. Patlasov
MPatlasov at parallels.com
Sun Dec 9 23:41:57 PST 2012
The patch implements passing "struct kiocb *async" down the stack up to
fuse_send_read/write where it is used to submit request asynchronously.
async==NULL 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 | 4 ++--
fs/fuse/file.c | 58 ++++++++++++++++++++++++++++++++++++------------------
fs/fuse/fuse_i.h | 2 +-
3 files changed, 42 insertions(+), 22 deletions(-)
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index 65ce10a..beb99e9 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -93,7 +93,7 @@ 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 };
- return fuse_direct_io(file, &iov, 1, count, &pos, 0);
+ return fuse_direct_io(file, &iov, 1, count, &pos, 0, NULL);
}
static ssize_t cuse_write(struct file *file, const char __user *buf,
@@ -106,7 +106,7 @@ static ssize_t cuse_write(struct file *file, const char __user *buf,
* 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(file, &iov, 1, count, &pos, 1, NULL);
}
static int cuse_open(struct inode *inode, struct file *file)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 634f54a..c585158 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -598,7 +598,8 @@ static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
}
static size_t fuse_send_read(struct fuse_req *req, struct file *file,
- loff_t pos, size_t count, fl_owner_t owner)
+ loff_t pos, size_t count, fl_owner_t owner,
+ struct kiocb *async)
{
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
@@ -610,6 +611,10 @@ 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 (async)
+ return fuse_async_req_send(fc, req, count, async);
+
fuse_request_send(fc, req);
return req->out.args[0].size;
}
@@ -662,7 +667,7 @@ 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, file, pos, count, NULL, NULL);
err = req->out.h.error;
fuse_put_request(fc, req);
@@ -865,7 +870,8 @@ static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
}
static size_t fuse_send_write(struct fuse_req *req, struct file *file,
- loff_t pos, size_t count, fl_owner_t owner)
+ loff_t pos, size_t count, fl_owner_t owner,
+ struct kiocb *async)
{
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
@@ -877,6 +883,10 @@ 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 (async)
+ return fuse_async_req_send(fc, req, count, async);
+
fuse_request_send(fc, req);
return req->misc.write.out.size;
}
@@ -904,7 +914,7 @@ static size_t fuse_send_write_pages(struct fuse_req *req, struct 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, file, pos, count, NULL, NULL);
offset = req->page_descs[0].offset;
count = res;
@@ -1244,7 +1254,7 @@ static inline int fuse_iter_npages(const struct iov_iter *ii_p)
ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
unsigned long nr_segs, size_t count, loff_t *ppos,
- int write)
+ int write, struct kiocb *async)
{
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = ff->fc;
@@ -1266,16 +1276,22 @@ 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 (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, file, pos, nbytes, owner,
+ async);
else
- nres = fuse_send_read(req, file, pos, nbytes, owner);
+ nres = fuse_send_read(req, file, pos, nbytes, owner,
+ async);
- fuse_release_user_pages(req, !write);
+ if (!async)
+ fuse_release_user_pages(req, !write);
if (req->out.h.error) {
if (!res)
res = req->out.h.error;
@@ -1290,13 +1306,14 @@ ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
if (nres != nbytes)
break;
if (count) {
- fuse_put_request(fc, req);
+ if (!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) && !async)
fuse_put_request(fc, req);
if (res > 0)
*ppos = pos;
@@ -1306,7 +1323,8 @@ 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,
- unsigned long nr_segs, loff_t *ppos)
+ unsigned long nr_segs, loff_t *ppos,
+ struct kiocb *async)
{
ssize_t res;
struct inode *inode = file->f_path.dentry->d_inode;
@@ -1315,7 +1333,7 @@ static ssize_t __fuse_direct_read(struct file *file, const struct iovec *iov,
return -EIO;
res = fuse_direct_io(file, iov, nr_segs, iov_length(iov, nr_segs),
- ppos, 0);
+ ppos, 0, async);
fuse_invalidate_attr(inode);
@@ -1326,11 +1344,12 @@ static ssize_t fuse_direct_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct iovec iov = { .iov_base = buf, .iov_len = count };
- return __fuse_direct_read(file, &iov, 1, ppos);
+ return __fuse_direct_read(file, &iov, 1, ppos, NULL);
}
static ssize_t __fuse_direct_write(struct file *file, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
+ unsigned long nr_segs, loff_t *ppos,
+ struct kiocb *async)
{
struct inode *inode = file->f_path.dentry->d_inode;
size_t count = iov_length(iov, nr_segs);
@@ -1338,8 +1357,9 @@ static ssize_t __fuse_direct_write(struct file *file, const struct iovec *iov,
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(file, iov, nr_segs, count, ppos, 1,
+ async);
+ if (!async && res > 0)
fuse_write_update_size(inode, *ppos);
}
@@ -1360,7 +1380,7 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
/* 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(file, &iov, 1, ppos, NULL);
mutex_unlock(&inode->i_mutex);
return res;
@@ -2333,9 +2353,9 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
pos = offset;
if (rw == WRITE)
- ret = __fuse_direct_write(file, iov, nr_segs, &pos);
+ ret = __fuse_direct_write(file, iov, nr_segs, &pos, NULL);
else
- ret = __fuse_direct_read(file, iov, nr_segs, &pos);
+ ret = __fuse_direct_read(file, iov, nr_segs, &pos, NULL);
return ret;
}
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 618d48a..173c959 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -828,7 +828,7 @@ 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,
unsigned long nr_segs, size_t count, loff_t *ppos,
- int write);
+ int write, struct kiocb *async);
long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
unsigned int flags);
long fuse_ioctl_common(struct file *file, unsigned int cmd,
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