nfsd: add support for the umask attribute

Clients can set the umask attribute when creating files to cause the
server to apply it always except when inheriting permissions from the
parent directory.  That way, the new files will end up with the same
permissions as files created locally.

See https://tools.ietf.org/html/draft-ietf-nfsv4-umask-02 for more
details.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index e901cf124e9f6fa53abecd2e0e2f5d33bed6263f..74a6e573e061afa73fba49d8c65a09b7d470229d 100644 (file)
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -102,6 +102,9 @@ check_attr_support(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                return nfserr_attrnotsupp;
        if (writable && !bmval_is_subset(bmval, writable))
                return nfserr_inval;
+       if (writable && (bmval[2] & FATTR4_WORD2_MODE_UMASK) &&
+                       (bmval[1] & FATTR4_WORD1_MODE))
+               return nfserr_inval;
        return nfs_ok;
 }
 

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 281739e1d4771333e8717526289af110bfff3b12..79edde4577b29457767a3cb85c1714350184513d 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -33,6 +33,7 @@
  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <linux/fs_struct.h>
 #include <linux/file.h>
 #include <linux/slab.h>
 #include <linux/namei.h>
@@ -299,7 +300,7 @@ nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
 static __be32
 nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
                   struct iattr *iattr, struct nfs4_acl **acl,
-                  struct xdr_netobj *label)
+                  struct xdr_netobj *label, int *umask)
 {
        int expected_len, len = 0;
        u32 dummy32;
@@ -457,6 +458,17 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
                        return nfserr_jukebox;
        }
 #endif
+       if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
+               if (!umask)
+                       goto xdr_error;
+               READ_BUF(8);
+               len += 8;
+               dummy32 = be32_to_cpup(p++);
+               iattr->ia_mode = dummy32 & (S_IFMT | S_IALLUGO);
+               dummy32 = be32_to_cpup(p++);
+               *umask = dummy32 & S_IRWXUGO;
+               iattr->ia_valid |= ATTR_MODE;
+       }
        if (len != expected_len)
                goto xdr_error;
 
@@ -651,7 +663,8 @@ nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create
                return status;
 
        status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr,
-                                   &create->cr_acl, &create->cr_label);
+                                   &create->cr_acl, &create->cr_label,
+                                   &current->fs->umask);
        if (status)
                goto out;
 
@@ -896,13 +909,15 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
        case NFS4_OPEN_NOCREATE:
                break;
        case NFS4_OPEN_CREATE:
+               current->fs->umask = 0;
                READ_BUF(4);
                open->op_createmode = be32_to_cpup(p++);
                switch (open->op_createmode) {
                case NFS4_CREATE_UNCHECKED:
                case NFS4_CREATE_GUARDED:
                        status = nfsd4_decode_fattr(argp, open->op_bmval,
-                               &open->op_iattr, &open->op_acl, &open->op_label);
+                               &open->op_iattr, &open->op_acl, &open->op_label,
+                               &current->fs->umask);
                        if (status)
                                goto out;
                        break;
@@ -916,7 +931,8 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
                        READ_BUF(NFS4_VERIFIER_SIZE);
                        COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
                        status = nfsd4_decode_fattr(argp, open->op_bmval,
-                               &open->op_iattr, &open->op_acl, &open->op_label);
+                               &open->op_iattr, &open->op_acl, &open->op_label,
+                               &current->fs->umask);
                        if (status)
                                goto out;
                        break;
@@ -1153,7 +1169,7 @@ nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *seta
        if (status)
                return status;
        return nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr,
-                                 &setattr->sa_acl, &setattr->sa_label);
+                                 &setattr->sa_acl, &setattr->sa_label, NULL);
 }
 
 static __be32

diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 7155239b2908fa1aa598e8aad80132368ccdd1ab..d74c8c44dc3536ffdd6a93b0cd340121233e5a95 100644 (file)
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -359,6 +359,7 @@ void                nfsd_lockd_shutdown(void);
 
 #define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
        (NFSD4_1_SUPPORTED_ATTRS_WORD2 | \
+       FATTR4_WORD2_MODE_UMASK | \
        NFSD4_2_SECURITY_ATTRS)
 
 extern u32 nfsd_suppattrs[3][3];
@@ -390,10 +391,14 @@ static inline bool nfsd_attrs_supported(u32 minorversion, u32 *bmval)
        (FATTR4_WORD1_MODE | FATTR4_WORD1_OWNER | FATTR4_WORD1_OWNER_GROUP \
        | FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET)
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-#define NFSD_WRITEABLE_ATTRS_WORD2 FATTR4_WORD2_SECURITY_LABEL
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL \
+       FATTR4_WORD2_SECURITY_LABEL
 #else
-#define NFSD_WRITEABLE_ATTRS_WORD2 0
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL 0
 #endif
+#define NFSD_WRITEABLE_ATTRS_WORD2 \
+       (FATTR4_WORD2_MODE_UMASK \
+       | MAYBE_FATTR4_WORD2_SECURITY_LABEL)
 
 #define NFSD_SUPPATTR_EXCLCREAT_WORD0 \
        NFSD_WRITEABLE_ATTRS_WORD0

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index a2b65fc56dd662ee39a9023d322b5a6131cc8d8c..e6bfd96734c006587bd1709d0df48818c2065789 100644 (file)
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -661,8 +661,8 @@ nfsd(void *vrqstp)
        mutex_lock(&nfsd_mutex);
 
        /* At this point, the thread shares current->fs
-        * with the init process. We need to create files with a
-        * umask of 0 instead of init's umask. */
+        * with the init process. We need to create files with the
+        * umask as defined by the client instead of init's umask. */
        if (unshare_fs_struct() < 0) {
                printk("Unable to start nfsd thread: out of memory\n");
                goto out;

diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 9094faf0699d61b7b07bc5b9b0d0e9f76dc67742..bca536341d1ae51781981906f069a96f612cf52f 100644 (file)
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -440,6 +440,7 @@ enum lock_type4 {
 #define FATTR4_WORD2_MDSTHRESHOLD       (1UL << 4)
 #define FATTR4_WORD2_CLONE_BLKSIZE     (1UL << 13)
 #define FATTR4_WORD2_SECURITY_LABEL     (1UL << 16)
+#define FATTR4_WORD2_MODE_UMASK                (1UL << 17)
 
 /* MDS threshold bitmap bits */
 #define THRESHOLD_RD                    (1UL << 0)