Obvious leak, which cannot detected unless you try to unload
fuse module. Found accidentally searching for reasons why
fuse_dev_find_request take 7% of cpu in profiles.
Also, make it in more optimal way, fget() is too expensive and
well seen on profiles, there is lighter way relying on rcu protection.
Signed-off-by: Alexey Kuznetsov <kuz...@virtuozzo.com>
Acked-by:: Liu Kui <kui....@virtuozzo.com>
---
fs/fuse/dev.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index f5594e4..1db40f0 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -19,6 +19,7 @@
#include <linux/slab.h>
#include <linux/pipe_fs_i.h>
#include <linux/swap.h>
+#include <linux/fdtable.h>
#include <linux/splice.h>
#include <linux/sched.h>
@@ -2678,16 +2679,29 @@ int fuse_dev_release(struct inode *inode, struct file
*file)
struct fuse_req *fuse_dev_find_request(int fd, u64 unique)
{
- struct file *f = fget(fd);
- struct fuse_dev *fud = fuse_get_dev(f);
- struct fuse_pqueue *fpq = &fud->pq;
+ struct file * file;
+ struct fuse_dev *fud;
+ struct fuse_pqueue *fpq;
struct fuse_req *req = NULL;
+ rcu_read_lock();
+ file = files_lookup_fd_rcu(current->files, fd);
+ if (!file)
+ goto out;
+
+ if (file->f_op != &fuse_dev_operations)
+ goto out;
+
+ fud = fuse_get_dev(file);
+ fpq = &fud->pq;
+
spin_lock(&fpq->lock);
if (fpq->connected)
req = request_find(&fud->pq, unique);
spin_unlock(&fpq->lock);
+out:
+ rcu_read_unlock();
return req;
}
EXPORT_SYMBOL_GPL(fuse_dev_find_request);
--
1.8.3.1
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