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>

1 files changed, 43 insertions, 25 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index c4b7832c38b5..75df600ec9b4 100644
--- 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 = {