NFSD: Refactor NFSv4 OPEN(CREATE)
[sfrench/cifs-2.6.git] / fs / nfsd / nfs4proc.c
index b207c76a873f3a86ca095c035505b4e07f82f61a..99c0485a29e9feef7515bba4046479455c45442a 100644 (file)
@@ -37,6 +37,8 @@
 #include <linux/falloc.h>
 #include <linux/slab.h>
 #include <linux/kthread.h>
+#include <linux/namei.h>
+
 #include <linux/sunrpc/addr.h>
 #include <linux/nfs_ssc.h>
 
@@ -235,6 +237,154 @@ static void nfsd4_set_open_owner_reply_cache(struct nfsd4_compound_state *cstate
                        &resfh->fh_handle);
 }
 
+static inline bool nfsd4_create_is_exclusive(int createmode)
+{
+       return createmode == NFS4_CREATE_EXCLUSIVE ||
+               createmode == NFS4_CREATE_EXCLUSIVE4_1;
+}
+
+/*
+ * Implement NFSv4's unchecked, guarded, and exclusive create
+ * semantics for regular files. Open state for this new file is
+ * subsequently fabricated in nfsd4_process_open2().
+ *
+ * Upon return, caller must release @fhp and @resfhp.
+ */
+static __be32
+nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
+                 struct svc_fh *resfhp, struct nfsd4_open *open)
+{
+       struct iattr *iap = &open->op_iattr;
+       struct dentry *parent, *child;
+       __u32 v_mtime, v_atime;
+       struct inode *inode;
+       __be32 status;
+       int host_err;
+
+       if (isdotent(open->op_fname, open->op_fnamelen))
+               return nfserr_exist;
+       if (!(iap->ia_valid & ATTR_MODE))
+               iap->ia_mode = 0;
+
+       status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+       if (status != nfs_ok)
+               return status;
+       parent = fhp->fh_dentry;
+       inode = d_inode(parent);
+
+       host_err = fh_want_write(fhp);
+       if (host_err)
+               return nfserrno(host_err);
+
+       fh_lock_nested(fhp, I_MUTEX_PARENT);
+
+       child = lookup_one_len(open->op_fname, parent, open->op_fnamelen);
+       if (IS_ERR(child)) {
+               status = nfserrno(PTR_ERR(child));
+               goto out;
+       }
+
+       if (d_really_is_negative(child)) {
+               status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+               if (status != nfs_ok)
+                       goto out;
+       }
+
+       status = fh_compose(resfhp, fhp->fh_export, child, fhp);
+       if (status != nfs_ok)
+               goto out;
+
+       v_mtime = 0;
+       v_atime = 0;
+       if (nfsd4_create_is_exclusive(open->op_createmode)) {
+               u32 *verifier = (u32 *)open->op_verf.data;
+
+               /*
+                * Solaris 7 gets confused (bugid 4218508) if these have
+                * the high bit set, as do xfs filesystems without the
+                * "bigtime" feature. So just clear the high bits. If this
+                * is ever changed to use different attrs for storing the
+                * verifier, then do_open_lookup() will also need to be
+                * fixed accordingly.
+                */
+               v_mtime = verifier[0] & 0x7fffffff;
+               v_atime = verifier[1] & 0x7fffffff;
+       }
+
+       if (d_really_is_positive(child)) {
+               status = nfs_ok;
+
+               switch (open->op_createmode) {
+               case NFS4_CREATE_UNCHECKED:
+                       if (!d_is_reg(child))
+                               break;
+
+                       /*
+                        * In NFSv4, we don't want to truncate the file
+                        * now. This would be wrong if the OPEN fails for
+                        * some other reason. Furthermore, if the size is
+                        * nonzero, we should ignore it according to spec!
+                        */
+                       open->op_truncate = (iap->ia_valid & ATTR_SIZE) &&
+                                               !iap->ia_size;
+                       break;
+               case NFS4_CREATE_GUARDED:
+                       status = nfserr_exist;
+                       break;
+               case NFS4_CREATE_EXCLUSIVE:
+                       if (d_inode(child)->i_mtime.tv_sec == v_mtime &&
+                           d_inode(child)->i_atime.tv_sec == v_atime &&
+                           d_inode(child)->i_size == 0) {
+                               open->op_created = true;
+                               break;          /* subtle */
+                       }
+                       status = nfserr_exist;
+                       break;
+               case NFS4_CREATE_EXCLUSIVE4_1:
+                       if (d_inode(child)->i_mtime.tv_sec == v_mtime &&
+                           d_inode(child)->i_atime.tv_sec == v_atime &&
+                           d_inode(child)->i_size == 0) {
+                               open->op_created = true;
+                               goto set_attr;  /* subtle */
+                       }
+                       status = nfserr_exist;
+               }
+               goto out;
+       }
+
+       if (!IS_POSIXACL(inode))
+               iap->ia_mode &= ~current_umask();
+
+       host_err = vfs_create(&init_user_ns, inode, child, iap->ia_mode, true);
+       if (host_err < 0) {
+               status = nfserrno(host_err);
+               goto out;
+       }
+       open->op_created = true;
+
+       /* A newly created file already has a file size of zero. */
+       if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
+               iap->ia_valid &= ~ATTR_SIZE;
+       if (nfsd4_create_is_exclusive(open->op_createmode)) {
+               iap->ia_valid = ATTR_MTIME | ATTR_ATIME |
+                               ATTR_MTIME_SET|ATTR_ATIME_SET;
+               iap->ia_mtime.tv_sec = v_mtime;
+               iap->ia_atime.tv_sec = v_atime;
+               iap->ia_mtime.tv_nsec = 0;
+               iap->ia_atime.tv_nsec = 0;
+       }
+
+set_attr:
+       status = nfsd_create_setattr(rqstp, fhp, resfhp, iap);
+
+out:
+       fh_unlock(fhp);
+       if (child && !IS_ERR(child))
+               dput(child);
+       fh_drop_write(fhp);
+       return status;
+}
+
 static __be32
 do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh **resfh)
 {
@@ -264,16 +414,8 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
                 * yes          | yes    | GUARDED4        | GUARDED4
                 */
 
-               /*
-                * Note: create modes (UNCHECKED,GUARDED...) are the same
-                * in NFSv4 as in v3 except EXCLUSIVE4_1.
-                */
                current->fs->umask = open->op_umask;
-               status = do_nfsd_create(rqstp, current_fh, open->op_fname,
-                                       open->op_fnamelen, &open->op_iattr,
-                                       *resfh, open->op_createmode,
-                                       (u32 *)open->op_verf.data,
-                                       &open->op_truncate, &open->op_created);
+               status = nfsd4_create_file(rqstp, current_fh, *resfh, open);
                current->fs->umask = 0;
 
                if (!status && open->op_label.len)
@@ -284,7 +426,7 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
                 * use the returned bitmask to indicate which attributes
                 * we used to store the verifier:
                 */
-               if (nfsd_create_is_exclusive(open->op_createmode) && status == 0)
+               if (nfsd4_create_is_exclusive(open->op_createmode) && status == 0)
                        open->op_bmval[1] |= (FATTR4_WORD1_TIME_ACCESS |
                                                FATTR4_WORD1_TIME_MODIFY);
        } else