ceph: implement i_op->atomic_open()

Add an ->atomic_open implementation which replaces the atomic lookup+open+create
operation implemented via ->lookup and ->create operations.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index c4b7832c38b56f6d0a92e2f69e969492a7568831..75df600ec9b43b17d919f3a66cf3dcd36c735ff5 100644 (file)
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -594,14 +594,6 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
        if (err < 0)
                return ERR_PTR(err);
 
-       /* open (but not create!) intent? */
-       if (nd &&
-           (nd->flags & LOOKUP_OPEN) &&
-           !(nd->intent.open.flags & O_CREAT)) {
-               int mode = nd->intent.open.create_mode & ~current->fs->umask;
-               return ceph_lookup_open(dir, dentry, nd, mode);
-       }
-
        /* can we conclude ENOENT locally? */
        if (dentry->d_inode == NULL) {
                struct ceph_inode_info *ci = ceph_inode(dir);
@@ -642,6 +634,47 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
        return dentry;
 }
 
+struct file *ceph_atomic_open(struct inode *dir, struct dentry *dentry,
+                             struct opendata *od, unsigned flags, umode_t mode,
+                             bool *created)
+{
+       int err;
+       struct dentry *res = NULL;
+       struct file *filp;
+
+       if (!(flags & O_CREAT)) {
+               if (dentry->d_name.len > NAME_MAX)
+                       return ERR_PTR(-ENAMETOOLONG);
+
+               err = ceph_init_dentry(dentry);
+               if (err < 0)
+                       return ERR_PTR(err);
+
+               return ceph_lookup_open(dir, dentry, od, flags, mode);
+       }
+
+       if (d_unhashed(dentry)) {
+               res = ceph_lookup(dir, dentry, NULL);
+               if (IS_ERR(res))
+                       return ERR_CAST(res);
+
+               if (res)
+                       dentry = res;
+       }
+
+       /* We don't deal with positive dentries here */
+       if (dentry->d_inode) {
+               finish_no_open(od, res);
+               return NULL;
+       }
+
+       *created = true;
+       filp = ceph_lookup_open(dir, dentry, od, flags, mode);
+       dput(res);
+
+       return filp;
+}
+
 /*
  * If we do a create but get no trace back from the MDS, follow up with
  * a lookup (the VFS expects us to link up the provided dentry).
@@ -702,23 +735,7 @@ static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
                       struct nameidata *nd)
 {
-       dout("create in dir %p dentry %p name '%.*s'\n",
-            dir, dentry, dentry->d_name.len, dentry->d_name.name);
-
-       if (ceph_snap(dir) != CEPH_NOSNAP)
-               return -EROFS;
-
-       if (nd) {
-               BUG_ON((nd->flags & LOOKUP_OPEN) == 0);
-               dentry = ceph_lookup_open(dir, dentry, nd, mode);
-               /* hrm, what should i do here if we get aliased? */
-               if (IS_ERR(dentry))
-                       return PTR_ERR(dentry);
-               return 0;
-       }
-
-       /* fall back to mknod */
-       return ceph_mknod(dir, dentry, (mode & ~S_IFMT) | S_IFREG, 0);
+       return ceph_mknod(dir, dentry, mode, 0);
 }
 
 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
@@ -1357,6 +1374,7 @@ const struct inode_operations ceph_dir_iops = {
        .rmdir = ceph_unlink,
        .rename = ceph_rename,
        .create = ceph_create,
+       .atomic_open = ceph_atomic_open,
 };
 
 const struct dentry_operations ceph_dentry_ops = {

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 4bf9773e6a36935aaf131a5211f8d6f0e3cf77d9..e34dc22e75a9b0a5e2ac56d2470cecb8b48e1087 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -213,21 +213,15 @@ out:
  * may_open() fails, the struct *file gets cleaned up (i.e.
  * ceph_release gets called).  So fear not!
  */
-/*
- * flags
- *  path_lookup_open   -> LOOKUP_OPEN
- *  path_lookup_create -> LOOKUP_OPEN|LOOKUP_CREATE
- */
-struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
-                               struct nameidata *nd, int mode)
+struct file *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
+                             struct opendata *od, unsigned flags, umode_t mode)
 {
        struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
        struct ceph_mds_client *mdsc = fsc->mdsc;
-       struct file *file;
+       struct file *file = NULL;
        struct ceph_mds_request *req;
        struct dentry *ret;
        int err;
-       int flags = nd->intent.open.flags;
 
        dout("ceph_lookup_open dentry %p '%.*s' flags %d mode 0%o\n",
             dentry, dentry->d_name.len, dentry->d_name.name, flags, mode);
@@ -253,14 +247,19 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
                err = ceph_handle_notrace_create(dir, dentry);
        if (err)
                goto out;
-       file = lookup_instantiate_filp(nd, req->r_dentry, ceph_open);
+       file = finish_open(od, req->r_dentry, ceph_open);
        if (IS_ERR(file))
                err = PTR_ERR(file);
 out:
        ret = ceph_finish_lookup(req, dentry, err);
        ceph_mdsc_put_request(req);
        dout("ceph_lookup_open result=%p\n", ret);
-       return ret;
+
+       if (IS_ERR(ret))
+               return ERR_CAST(ret);
+
+       dput(ret);
+       return err ? ERR_PTR(err) : file;
 }
 
 int ceph_release(struct inode *inode, struct file *file)

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 8471db98b62c8b28578a596e822ddd357aac7168..e61e54673e561b4c52b02f9e035cf80af7024a68 100644 (file)
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -806,8 +806,9 @@ extern int ceph_copy_from_page_vector(struct page **pages,
                                    loff_t off, size_t len);
 extern struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags);
 extern int ceph_open(struct inode *inode, struct file *file);
-extern struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
-                                      struct nameidata *nd, int mode);
+extern struct file *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
+                                    struct opendata *od, unsigned flags,
+                                    umode_t mode);
 extern int ceph_release(struct inode *inode, struct file *filp);
 
 /* dir.c */