ceph: preallocate inode for ops that may create one

When creating a new inode, we need to determine the crypto context
before we can transmit the RPC. The fscrypt API has a routine for getting
a crypto context before a create occurs, but it requires an inode.

Change the ceph code to preallocate an inode in advance of a create of
any sort (open(), mknod(), symlink(), etc). Move the existing code that
generates the ACL and SELinux blobs into this routine since that's
mostly common across all the different codepaths.

In most cases, we just want to allow ceph_fill_trace to use that inode
after the reply comes in, so add a new field to the MDS request for it
(r_new_inode).

The async create codepath is a bit different though. In that case, we
want to hash the inode in advance of the RPC so that it can be used
before the reply comes in. If the call subsequently fails with
-EJUKEBOX, then just put the references and clean up the as_ctx. Note
that with this change, we now need to regenerate the as_ctx when this
occurs, but it's quite rare for it to happen.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index b9cad57ce606..eb621bb276bd 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -999,6 +999,7 @@ static inline bool __ceph_have_pending_cap_snap(struct ceph_inode_info *ci)
 /* inode.c */
 struct ceph_mds_reply_info_in;
 struct ceph_mds_reply_dirfrag;
+struct ceph_acl_sec_ctx;
 
 extern const struct inode_operations ceph_file_iops;
 
@@ -1006,8 +1007,14 @@ extern struct inode *ceph_alloc_inode(struct super_block *sb);
 extern void ceph_evict_inode(struct inode *inode);
 extern void ceph_free_inode(struct inode *inode);
 
+struct inode *ceph_new_inode(struct inode *dir, struct dentry *dentry,
+			     umode_t *mode, struct ceph_acl_sec_ctx *as_ctx);
+void ceph_as_ctx_to_req(struct ceph_mds_request *req,
+			struct ceph_acl_sec_ctx *as_ctx);
+
 extern struct inode *ceph_get_inode(struct super_block *sb,
-				    struct ceph_vino vino);
+				    struct ceph_vino vino,
+				    struct inode *newino);
 extern struct inode *ceph_get_snapdir(struct inode *parent);
 extern int ceph_fill_file_size(struct inode *inode, int issued,
 			       u32 truncate_seq, u64 truncate_size, u64 size);