fuse: introduce fuse_simple_request() helper

The following pattern is repeated many times:

	req = fuse_get_req_nopages(fc);
	/* Initialize req->(in|out).args */
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(req);

Create a new replacement helper:

	/* Initialize args */
	err = fuse_simple_request(fc, &args);

In addition to reducing the code size, this will ease moving from the
complex arg-based to a simpler page-based I/O on the fuse device.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

1 files changed, 72 insertions, 117 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 2d4ae68943bb..e8729ac30762 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -24,30 +24,22 @@ static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
                           int opcode, struct fuse_open_out *outargp)
 {
         struct fuse_open_in inarg;
-        struct fuse_req *req;
-        int err;
-
-        req = fuse_get_req_nopages(fc);
-        if (IS_ERR(req))
-                return PTR_ERR(req);
+        FUSE_ARGS(args);
 
         memset(&inarg, 0, sizeof(inarg));
         inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
         if (!fc->atomic_o_trunc)
                 inarg.flags &= ~O_TRUNC;
-        req->in.h.opcode = opcode;
-        req->in.h.nodeid = nodeid;
-        req->in.numargs = 1;
-        req->in.args[0].size = sizeof(inarg);
-        req->in.args[0].value = &inarg;
-        req->out.numargs = 1;
-        req->out.args[0].size = sizeof(*outargp);
-        req->out.args[0].value = outargp;
-        fuse_request_send(fc, req);
-        err = req->out.h.error;
-        fuse_put_request(fc, req);
+        args.in.h.opcode = opcode;
+        args.in.h.nodeid = nodeid;
+        args.in.numargs = 1;
+        args.in.args[0].size = sizeof(inarg);
+        args.in.args[0].value = &inarg;
+        args.out.numargs = 1;
+        args.out.args[0].size = sizeof(*outargp);
+        args.out.args[0].value = outargp;
 
-        return err;
+        return fuse_simple_request(fc, &args);
 }
 
 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
@@ -451,7 +443,7 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
         struct inode *inode = file->f_mapping->host;
         struct fuse_conn *fc = get_fuse_conn(inode);
         struct fuse_file *ff = file->private_data;
-        struct fuse_req *req;
+        FUSE_ARGS(args);
         struct fuse_fsync_in inarg;
         int err;
 
@@ -477,23 +469,15 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
         if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
                 goto out;
 
-        req = fuse_get_req_nopages(fc);
-        if (IS_ERR(req)) {
-                err = PTR_ERR(req);
-                goto out;
-        }
-
         memset(&inarg, 0, sizeof(inarg));
         inarg.fh = ff->fh;
         inarg.fsync_flags = datasync ? 1 : 0;
-        req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
-        req->in.h.nodeid = get_node_id(inode);
-        req->in.numargs = 1;
-        req->in.args[0].size = sizeof(inarg);
-        req->in.args[0].value = &inarg;
-        fuse_request_send(fc, req);
-        err = req->out.h.error;
-        fuse_put_request(fc, req);
+        args.in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
+        args.in.h.nodeid = get_node_id(inode);
+        args.in.numargs = 1;
+        args.in.args[0].size = sizeof(inarg);
+        args.in.args[0].value = &inarg;
+        err = fuse_simple_request(fc, &args);
         if (err == -ENOSYS) {
                 if (isdir)
                         fc->no_fsyncdir = 1;
@@ -2127,49 +2111,44 @@ static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
         return 0;
 }
 
-static void fuse_lk_fill(struct fuse_req *req, struct file *file,
+static void fuse_lk_fill(struct fuse_args *args, struct file *file,
                          const struct file_lock *fl, int opcode, pid_t pid,
-                         int flock)
+                         int flock, struct fuse_lk_in *inarg)
 {
         struct inode *inode = file_inode(file);
         struct fuse_conn *fc = get_fuse_conn(inode);
         struct fuse_file *ff = file->private_data;
-        struct fuse_lk_in *arg = &req->misc.lk_in;
-
-        arg->fh = ff->fh;
-        arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
-        arg->lk.start = fl->fl_start;
-        arg->lk.end = fl->fl_end;
-        arg->lk.type = fl->fl_type;
-        arg->lk.pid = pid;
+
+        memset(inarg, 0, sizeof(*inarg));
+        inarg->fh = ff->fh;
+        inarg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
+        inarg->lk.start = fl->fl_start;
+        inarg->lk.end = fl->fl_end;
+        inarg->lk.type = fl->fl_type;
+        inarg->lk.pid = pid;
         if (flock)
-                arg->lk_flags |= FUSE_LK_FLOCK;
-        req->in.h.opcode = opcode;
-        req->in.h.nodeid = get_node_id(inode);
-        req->in.numargs = 1;
-        req->in.args[0].size = sizeof(*arg);
-        req->in.args[0].value = arg;
+                inarg->lk_flags |= FUSE_LK_FLOCK;
+        args->in.h.opcode = opcode;
+        args->in.h.nodeid = get_node_id(inode);
+        args->in.numargs = 1;
+        args->in.args[0].size = sizeof(*inarg);
+        args->in.args[0].value = inarg;
 }
 
 static int fuse_getlk(struct file *file, struct file_lock *fl)
 {
         struct inode *inode = file_inode(file);
         struct fuse_conn *fc = get_fuse_conn(inode);
-        struct fuse_req *req;
+        FUSE_ARGS(args);
+        struct fuse_lk_in inarg;
         struct fuse_lk_out outarg;
         int err;
 
-        req = fuse_get_req_nopages(fc);
-        if (IS_ERR(req))
-                return PTR_ERR(req);
-
-        fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
-        req->out.numargs = 1;
-        req->out.args[0].size = sizeof(outarg);
-        req->out.args[0].value = &outarg;
-        fuse_request_send(fc, req);
-        err = req->out.h.error;
-        fuse_put_request(fc, req);
+        fuse_lk_fill(&args, file, fl, FUSE_GETLK, 0, 0, &inarg);
+        args.out.numargs = 1;
+        args.out.args[0].size = sizeof(outarg);
+        args.out.args[0].value = &outarg;
+        err = fuse_simple_request(fc, &args);
         if (!err)
                 err = convert_fuse_file_lock(&outarg.lk, fl);
 
@@ -2180,7 +2159,8 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 {
         struct inode *inode = file_inode(file);
         struct fuse_conn *fc = get_fuse_conn(inode);
-        struct fuse_req *req;
+        FUSE_ARGS(args);
+        struct fuse_lk_in inarg;
         int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
         pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
         int err;
@@ -2194,17 +2174,13 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
         if (fl->fl_flags & FL_CLOSE)
                 return 0;
 
-        req = fuse_get_req_nopages(fc);
-        if (IS_ERR(req))
-                return PTR_ERR(req);
+        fuse_lk_fill(&args, file, fl, opcode, pid, flock, &inarg);
+        err = fuse_simple_request(fc, &args);
 
-        fuse_lk_fill(req, file, fl, opcode, pid, flock);
-        fuse_request_send(fc, req);
-        err = req->out.h.error;
         /* locking is restartable */
         if (err == -EINTR)
                 err = -ERESTARTSYS;
-        fuse_put_request(fc, req);
+
         return err;
 }
 
@@ -2254,7 +2230,7 @@ static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
 {
         struct inode *inode = mapping->host;
         struct fuse_conn *fc = get_fuse_conn(inode);
-        struct fuse_req *req;
+        FUSE_ARGS(args);
         struct fuse_bmap_in inarg;
         struct fuse_bmap_out outarg;
         int err;
@@ -2262,24 +2238,18 @@ static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
         if (!inode->i_sb->s_bdev || fc->no_bmap)
                 return 0;
 
-        req = fuse_get_req_nopages(fc);
-        if (IS_ERR(req))
-                return 0;
-
         memset(&inarg, 0, sizeof(inarg));
         inarg.block = block;
         inarg.blocksize = inode->i_sb->s_blocksize;
-        req->in.h.opcode = FUSE_BMAP;
-        req->in.h.nodeid = get_node_id(inode);
-        req->in.numargs = 1;
-        req->in.args[0].size = sizeof(inarg);
-        req->in.args[0].value = &inarg;
-        req->out.numargs = 1;
-        req->out.args[0].size = sizeof(outarg);
-        req->out.args[0].value = &outarg;
-        fuse_request_send(fc, req);
-        err = req->out.h.error;
-        fuse_put_request(fc, req);
+        args.in.h.opcode = FUSE_BMAP;
+        args.in.h.nodeid = get_node_id(inode);
+        args.in.numargs = 1;
+        args.in.args[0].size = sizeof(inarg);
+        args.in.args[0].value = &inarg;
+        args.out.numargs = 1;
+        args.out.args[0].size = sizeof(outarg);
+        args.out.args[0].value = &outarg;
+        err = fuse_simple_request(fc, &args);
         if (err == -ENOSYS)
                 fc->no_bmap = 1;
 
@@ -2747,7 +2717,7 @@ unsigned fuse_file_poll(struct file *file, poll_table *wait)
         struct fuse_conn *fc = ff->fc;
         struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
         struct fuse_poll_out outarg;
-        struct fuse_req *req;
+        FUSE_ARGS(args);
         int err;
 
         if (fc->no_poll)
@@ -2765,21 +2735,15 @@ unsigned fuse_file_poll(struct file *file, poll_table *wait)
                 fuse_register_polled_file(fc, ff);
         }
 
-        req = fuse_get_req_nopages(fc);
-        if (IS_ERR(req))
-                return POLLERR;
-
-        req->in.h.opcode = FUSE_POLL;
-        req->in.h.nodeid = ff->nodeid;
-        req->in.numargs = 1;
-        req->in.args[0].size = sizeof(inarg);
-        req->in.args[0].value = &inarg;
-        req->out.numargs = 1;
-        req->out.args[0].size = sizeof(outarg);
-        req->out.args[0].value = &outarg;
-        fuse_request_send(fc, req);
-        err = req->out.h.error;
-        fuse_put_request(fc, req);
+        args.in.h.opcode = FUSE_POLL;
+        args.in.h.nodeid = ff->nodeid;
+        args.in.numargs = 1;
+        args.in.args[0].size = sizeof(inarg);
+        args.in.args[0].value = &inarg;
+        args.out.numargs = 1;
+        args.out.args[0].size = sizeof(outarg);
+        args.out.args[0].value = &outarg;
+        err = fuse_simple_request(fc, &args);
 
         if (!err)
                 return outarg.revents;
@@ -2923,7 +2887,7 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
         struct inode *inode = file->f_inode;
         struct fuse_inode *fi = get_fuse_inode(inode);
         struct fuse_conn *fc = ff->fc;
-        struct fuse_req *req;
+        FUSE_ARGS(args);
         struct fuse_fallocate_in inarg = {
                 .fh = ff->fh,
                 .offset = offset,
@@ -2956,25 +2920,16 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
         if (!(mode & FALLOC_FL_KEEP_SIZE))
                 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
 
-        req = fuse_get_req_nopages(fc);
-        if (IS_ERR(req)) {
-                err = PTR_ERR(req);
-                goto out;
-        }
-
-        req->in.h.opcode = FUSE_FALLOCATE;
-        req->in.h.nodeid = ff->nodeid;
-        req->in.numargs = 1;
-        req->in.args[0].size = sizeof(inarg);
-        req->in.args[0].value = &inarg;
-        fuse_request_send(fc, req);
-        err = req->out.h.error;
+        args.in.h.opcode = FUSE_FALLOCATE;
+        args.in.h.nodeid = ff->nodeid;
+        args.in.numargs = 1;
+        args.in.args[0].size = sizeof(inarg);
+        args.in.args[0].value = &inarg;
+        err = fuse_simple_request(fc, &args);
         if (err == -ENOSYS) {
                 fc->no_fallocate = 1;
                 err = -EOPNOTSUPP;
         }
-        fuse_put_request(fc, req);
-
         if (err)
                 goto out;