[PATCH] FUSE: atomic create+open

[safe/jmp/linux-2.6] / fs / fuse / dir.c

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 4bc1afc..83be119 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -13,6 +13,7 @@
 #include <linux/gfp.h>
 #include <linux/sched.h>
 #include <linux/namei.h>
+#include <linux/mount.h>
 
 static inline unsigned long time_to_jiffies(unsigned long sec,
                                            unsigned long nsec)
@@ -134,6 +135,101 @@ static void fuse_invalidate_entry(struct dentry *entry)
        entry->d_time = jiffies - 1;
 }
 
+static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
+                           struct nameidata *nd)
+{
+       int err;
+       struct inode *inode;
+       struct fuse_conn *fc = get_fuse_conn(dir);
+       struct fuse_req *req;
+       struct fuse_open_in inarg;
+       struct fuse_open_out outopen;
+       struct fuse_entry_out outentry;
+       struct fuse_inode *fi;
+       struct fuse_file *ff;
+       struct file *file;
+       int flags = nd->intent.open.flags - 1;
+
+       err = -ENOSYS;
+       if (fc->no_create)
+               goto out;
+
+       err = -ENAMETOOLONG;
+       if (entry->d_name.len > FUSE_NAME_MAX)
+               goto out;
+
+       err = -EINTR;
+       req = fuse_get_request(fc);
+       if (!req)
+               goto out;
+
+       ff = fuse_file_alloc();
+       if (!ff)
+               goto out_put_request;
+
+       flags &= ~O_NOCTTY;
+       memset(&inarg, 0, sizeof(inarg));
+       inarg.flags = flags;
+       inarg.mode = mode;
+       req->in.h.opcode = FUSE_CREATE;
+       req->in.h.nodeid = get_node_id(dir);
+       req->inode = dir;
+       req->in.numargs = 2;
+       req->in.args[0].size = sizeof(inarg);
+       req->in.args[0].value = &inarg;
+       req->in.args[1].size = entry->d_name.len + 1;
+       req->in.args[1].value = entry->d_name.name;
+       req->out.numargs = 2;
+       req->out.args[0].size = sizeof(outentry);
+       req->out.args[0].value = &outentry;
+       req->out.args[1].size = sizeof(outopen);
+       req->out.args[1].value = &outopen;
+       request_send(fc, req);
+       err = req->out.h.error;
+       if (err) {
+               if (err == -ENOSYS)
+                       fc->no_create = 1;
+               goto out_free_ff;
+       }
+
+       err = -EIO;
+       if (!S_ISREG(outentry.attr.mode))
+               goto out_free_ff;
+
+       inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
+                         &outentry.attr);
+       err = -ENOMEM;
+       if (!inode) {
+               flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
+               ff->fh = outopen.fh;
+               fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0);
+               goto out_put_request;
+       }
+       fuse_put_request(fc, req);
+       entry->d_time = time_to_jiffies(outentry.entry_valid,
+                                       outentry.entry_valid_nsec);
+       fi = get_fuse_inode(inode);
+       fi->i_time = time_to_jiffies(outentry.attr_valid,
+                                    outentry.attr_valid_nsec);
+
+       d_instantiate(entry, inode);
+       file = lookup_instantiate_filp(nd, entry, generic_file_open);
+       if (IS_ERR(file)) {
+               ff->fh = outopen.fh;
+               fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0);
+               return PTR_ERR(file);
+       }
+       fuse_finish_open(inode, file, ff, &outopen);
+       return 0;
+
+ out_free_ff:
+       fuse_file_free(ff);
+ out_put_request:
+       fuse_put_request(fc, req);
+ out:
+       return err;
+}
+
 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
                            struct inode *dir, struct dentry *entry,
                            int mode)
@@ -208,6 +304,12 @@ static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
 static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
                       struct nameidata *nd)
 {
+       if (nd && (nd->flags & LOOKUP_CREATE)) {
+               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);
 }
 
@@ -767,7 +869,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
                                  struct nameidata *nd)
 {
        struct inode *inode;
-       int err = fuse_lookup_iget(dir, entry, &inode);
+       int err;
+
+       err = fuse_lookup_iget(dir, entry, &inode);
        if (err)
                return ERR_PTR(err);
        if (inode && S_ISDIR(inode->i_mode)) {