fuse: implement i_op->atomic_open()
Add an ->atomic_open implementation which replaces the atomic open+create
operation implemented via ->create. No functionality is changed.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index f7543f7..e42442f 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -369,8 +369,9 @@
* If the filesystem doesn't support this, then fall back to separate
* 'mknod' + 'open' requests.
*/
-static int fuse_create_open(struct inode *dir, struct dentry *entry,
- umode_t mode, struct nameidata *nd)
+static struct file *fuse_create_open(struct inode *dir, struct dentry *entry,
+ struct opendata *od, unsigned flags,
+ umode_t mode)
{
int err;
struct inode *inode;
@@ -382,14 +383,11 @@
struct fuse_entry_out outentry;
struct fuse_file *ff;
struct file *file;
- int flags = nd->intent.open.flags;
-
- if (fc->no_create)
- return -ENOSYS;
forget = fuse_alloc_forget();
+ err = -ENOMEM;
if (!forget)
- return -ENOMEM;
+ goto out_err;
req = fuse_get_req(fc);
err = PTR_ERR(req);
@@ -428,11 +426,8 @@
req->out.args[1].value = &outopen;
fuse_request_send(fc, req);
err = req->out.h.error;
- if (err) {
- if (err == -ENOSYS)
- fc->no_create = 1;
+ if (err)
goto out_free_ff;
- }
err = -EIO;
if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
@@ -448,28 +443,78 @@
flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
fuse_sync_release(ff, flags);
fuse_queue_forget(fc, forget, outentry.nodeid, 1);
- return -ENOMEM;
+ err = -ENOMEM;
+ goto out_err;
}
kfree(forget);
d_instantiate(entry, inode);
fuse_change_entry_timeout(entry, &outentry);
fuse_invalidate_attr(dir);
- file = lookup_instantiate_filp(nd, entry, generic_file_open);
+ file = finish_open(od, entry, generic_file_open);
if (IS_ERR(file)) {
fuse_sync_release(ff, flags);
- return PTR_ERR(file);
+ } else {
+ file->private_data = fuse_file_get(ff);
+ fuse_finish_open(inode, file);
}
- file->private_data = fuse_file_get(ff);
- fuse_finish_open(inode, file);
- return 0;
+ return file;
- out_free_ff:
+out_free_ff:
fuse_file_free(ff);
- out_put_request:
+out_put_request:
fuse_put_request(fc, req);
- out_put_forget_req:
+out_put_forget_req:
kfree(forget);
- return err;
+out_err:
+ return ERR_PTR(err);
+}
+
+static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);
+static struct file *fuse_atomic_open(struct inode *dir, struct dentry *entry,
+ struct opendata *od, unsigned flags,
+ umode_t mode, bool *created)
+{
+ int err;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ struct file *file;
+ struct dentry *res = NULL;
+
+ if (d_unhashed(entry)) {
+ res = fuse_lookup(dir, entry, NULL);
+ if (IS_ERR(res))
+ return ERR_CAST(res);
+
+ if (res)
+ entry = res;
+ }
+
+ if (!(flags & O_CREAT) || entry->d_inode)
+ goto no_open;
+
+ /* Only creates */
+ *created = true;
+
+ if (fc->no_create)
+ goto mknod;
+
+ file = fuse_create_open(dir, entry, od, flags, mode);
+ if (PTR_ERR(file) == -ENOSYS) {
+ fc->no_create = 1;
+ goto mknod;
+ }
+out_dput:
+ dput(res);
+ return file;
+
+mknod:
+ err = fuse_mknod(dir, entry, mode, 0);
+ if (err) {
+ file = ERR_PTR(err);
+ goto out_dput;
+ }
+no_open:
+ finish_no_open(od, res);
+ return NULL;
}
/*
@@ -573,12 +618,6 @@
static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
struct nameidata *nd)
{
- if (nd) {
- int err = fuse_create_open(dir, entry, mode, nd);
- if (err != -ENOSYS)
- return err;
- /* Fall back on mknod */
- }
return fuse_mknod(dir, entry, mode, 0);
}
@@ -1646,6 +1685,7 @@
.link = fuse_link,
.setattr = fuse_setattr,
.create = fuse_create,
+ .atomic_open = fuse_atomic_open,
.mknod = fuse_mknod,
.permission = fuse_permission,
.getattr = fuse_getattr,