fuse: convert release to simple api

Since we cannot reserve the request structure up-front, make sure that the
request allocation doesn't fail using __GFP_NOFAIL.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

2 files changed, 42 insertions, 41 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 399b89b29bb4..56ed45ef3058 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -53,6 +53,12 @@ static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
         return fuse_simple_request(fc, &args);
 }
 
+struct fuse_release_args {
+        struct fuse_args args;
+        struct fuse_release_in inarg;
+        struct inode *inode;
+};
+
 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
 {
         struct fuse_file *ff;
@@ -62,8 +68,8 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
                 return NULL;
 
         ff->fc = fc;
-        ff->reserved_req = fuse_request_alloc(0);
-        if (unlikely(!ff->reserved_req)) {
+        ff->release_args = kzalloc(sizeof(*ff->release_args), GFP_KERNEL);
+        if (!ff->release_args) {
                 kfree(ff);
                 return NULL;
         }
@@ -81,7 +87,7 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
 
 void fuse_file_free(struct fuse_file *ff)
 {
-        fuse_request_free(ff->reserved_req);
+        kfree(ff->release_args);
         mutex_destroy(&ff->readdir.lock);
         kfree(ff);
 }
@@ -92,34 +98,31 @@ static struct fuse_file *fuse_file_get(struct fuse_file *ff)
         return ff;
 }
 
-static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
+static void fuse_release_end(struct fuse_conn *fc, struct fuse_args *args,
+                             int error)
 {
-        iput(req->misc.release.inode);
+        struct fuse_release_args *ra = container_of(args, typeof(*ra), args);
+
+        iput(ra->inode);
+        kfree(ra);
 }
 
 static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir)
 {
         if (refcount_dec_and_test(&ff->count)) {
-                struct fuse_req *req = ff->reserved_req;
+                struct fuse_args *args = &ff->release_args->args;
 
                 if (isdir ? ff->fc->no_opendir : ff->fc->no_open) {
-                        /*
-                         * Drop the release request when client does not
-                         * implement 'open'
-                         */
-                        __clear_bit(FR_BACKGROUND, &req->flags);
-                        iput(req->misc.release.inode);
-                        fuse_put_request(ff->fc, req);
+                        /* Do nothing when client does not implement 'open' */
+                        fuse_release_end(ff->fc, args, 0);
                 } else if (sync) {
-                        __set_bit(FR_FORCE, &req->flags);
-                        __clear_bit(FR_BACKGROUND, &req->flags);
-                        fuse_request_send(ff->fc, req);
-                        iput(req->misc.release.inode);
-                        fuse_put_request(ff->fc, req);
+                        fuse_simple_request(ff->fc, args);
+                        fuse_release_end(ff->fc, args, 0);
                 } else {
-                        req->end = fuse_release_end;
-                        __set_bit(FR_BACKGROUND, &req->flags);
-                        fuse_request_send_background(ff->fc, req);
+                        args->end = fuse_release_end;
+                        if (fuse_simple_background(ff->fc, args,
+                                                   GFP_KERNEL | __GFP_NOFAIL))
+                                fuse_release_end(ff->fc, args, -ENOTCONN);
                 }
                 kfree(ff);
         }
@@ -239,8 +242,7 @@ static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
                                  int flags, int opcode)
 {
         struct fuse_conn *fc = ff->fc;
-        struct fuse_req *req = ff->reserved_req;
-        struct fuse_release_in *inarg = &req->misc.release.in;
+        struct fuse_release_args *ra = ff->release_args;
 
         /* Inode is NULL on error path of fuse_create_open() */
         if (likely(fi)) {
@@ -255,32 +257,33 @@ static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
 
         wake_up_interruptible_all(&ff->poll_wait);
 
-        inarg->fh = ff->fh;
-        inarg->flags = flags;
-        req->in.h.opcode = opcode;
-        req->in.h.nodeid = ff->nodeid;
-        req->in.numargs = 1;
-        req->in.args[0].size = sizeof(struct fuse_release_in);
-        req->in.args[0].value = inarg;
+        ra->inarg.fh = ff->fh;
+        ra->inarg.flags = flags;
+        ra->args.in_numargs = 1;
+        ra->args.in_args[0].size = sizeof(struct fuse_release_in);
+        ra->args.in_args[0].value = &ra->inarg;
+        ra->args.opcode = opcode;
+        ra->args.nodeid = ff->nodeid;
+        ra->args.force = true;
+        ra->args.nocreds = true;
 }
 
 void fuse_release_common(struct file *file, bool isdir)
 {
         struct fuse_inode *fi = get_fuse_inode(file_inode(file));
         struct fuse_file *ff = file->private_data;
-        struct fuse_req *req = ff->reserved_req;
+        struct fuse_release_args *ra = ff->release_args;
         int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
 
         fuse_prepare_release(fi, ff, file->f_flags, opcode);
 
         if (ff->flock) {
-                struct fuse_release_in *inarg = &req->misc.release.in;
-                inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
-                inarg->lock_owner = fuse_lock_owner_id(ff->fc,
-                                                       (fl_owner_t) file);
+                ra->inarg.release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
+                ra->inarg.lock_owner = fuse_lock_owner_id(ff->fc,
+                                                          (fl_owner_t) file);
         }
         /* Hold inode until release is finished */
-        req->misc.release.inode = igrab(file_inode(file));
+        ra->inode = igrab(file_inode(file));
 
         /*
          * Normally this will send the RELEASE request, however if
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index a9d707bf2e69..a055a45361ef 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -164,17 +164,15 @@ enum {
 };
 
 struct fuse_conn;
+struct fuse_release_args;
 
 /** FUSE specific file data */
 struct fuse_file {
         /** Fuse connection for this file */
         struct fuse_conn *fc;
 
-        /*
-         * Request reserved for flush and release.
-         * Modified under relative fuse_inode::lock.
-         */
-        struct fuse_req *reserved_req;
+        /* Argument space reserved for release */
+        struct fuse_release_args *release_args;
 
         /** Kernel file handle guaranteed to be unique */
         u64 kh;