[PATCH v5 5/7] NFSv4: Add O_DENY* open flags support

[Pavel Shilovsky <piastry@etersoft.ru>]

by passing these flags to NFSv4 open request. Also make it return
-EBUSY on share conflicts with other opens.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
---
 fs/nfs/internal.h  |  3 ++-
 fs/nfs/nfs4proc.c  |  4 +++-
 fs/nfs/nfs4super.c |  9 ++++++---
 fs/nfs/nfs4xdr.c   | 21 +++++++++++++++++----
 fs/nfs/super.c     |  7 +++++--
 5 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index f0e6c7d..c770830 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -6,7 +6,8 @@
 #include <linux/mount.h>
 #include <linux/security.h>
 
-#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
+#define NFS_MS_MASK (MS_RDONLY | MS_NOSUID | MS_NODEV | MS_NOEXEC | \
+		     MS_SYNCHRONOUS | MS_SHARELOCK)
 
 struct nfs_string;
 
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 3cb5e77..5d44763 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -100,7 +100,7 @@ static int nfs4_map_errors(int err)
 	case -NFS4ERR_BADNAME:
 		return -EINVAL;
 	case -NFS4ERR_SHARE_DENIED:
-		return -EACCES;
+		return -EBUSY;
 	case -NFS4ERR_MINOR_VERS_MISMATCH:
 		return -EPROTONOSUPPORT;
 	case -NFS4ERR_ACCESS:
@@ -793,6 +793,8 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
 	atomic_inc(&sp->so_count);
 	p->o_arg.fh = NFS_FH(dir);
 	p->o_arg.open_flags = flags;
+	if (!IS_SHARELOCK(dir))
+		p->o_arg.open_flags &= ~(O_DENYREAD | O_DENYWRITE);
 	p->o_arg.fmode = fmode & (FMODE_READ|FMODE_WRITE);
 	/* don't put an ACCESS op in OPEN compound if O_EXCL, because ACCESS
 	 * will return permission denied for all bits until close */
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index 84d2e9e..ca791cd 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -28,7 +28,8 @@ static struct file_system_type nfs4_remote_fs_type = {
 	.name		= "nfs4",
 	.mount		= nfs4_remote_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE | FS_REVAL_DOT |
+			  FS_BINARY_MOUNTDATA | FS_DOES_SHARELOCK,
 };
 
 static struct file_system_type nfs4_remote_referral_fs_type = {
@@ -36,7 +37,8 @@ static struct file_system_type nfs4_remote_referral_fs_type = {
 	.name		= "nfs4",
 	.mount		= nfs4_remote_referral_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE | FS_REVAL_DOT |
+			  FS_BINARY_MOUNTDATA | FS_DOES_SHARELOCK,
 };
 
 struct file_system_type nfs4_referral_fs_type = {
@@ -44,7 +46,8 @@ struct file_system_type nfs4_referral_fs_type = {
 	.name		= "nfs4",
 	.mount		= nfs4_referral_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE | FS_REVAL_DOT |
+			  FS_BINARY_MOUNTDATA | FS_DOES_SHARELOCK,
 };
 
 static const struct super_operations nfs4_sops = {
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 26b1439..8fe0221 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1325,7 +1325,8 @@ static void encode_lookup(struct xdr_stream *xdr, const struct qstr *name, struc
 	encode_string(xdr, name->len, name->name);
 }
 
-static void encode_share_access(struct xdr_stream *xdr, fmode_t fmode)
+static void encode_share_access(struct xdr_stream *xdr, fmode_t fmode,
+				int open_flags)
 {
 	__be32 *p;
 
@@ -1343,7 +1344,19 @@ static void encode_share_access(struct xdr_stream *xdr, fmode_t fmode)
 	default:
 		*p++ = cpu_to_be32(0);
 	}
-	*p = cpu_to_be32(0);		/* for linux, share_deny = 0 always */
+	switch (open_flags & (O_DENYREAD|O_DENYWRITE)) {
+	case O_DENYREAD:
+		*p = cpu_to_be32(NFS4_SHARE_DENY_READ);
+		break;
+	case O_DENYWRITE:
+		*p = cpu_to_be32(NFS4_SHARE_DENY_WRITE);
+		break;
+	case O_DENYREAD|O_DENYWRITE:
+		*p = cpu_to_be32(NFS4_SHARE_DENY_BOTH);
+		break;
+	default:
+		*p = cpu_to_be32(0);
+	}
 }
 
 static inline void encode_openhdr(struct xdr_stream *xdr, const struct nfs_openargs *arg)
@@ -1354,7 +1367,7 @@ static inline void encode_openhdr(struct xdr_stream *xdr, const struct nfs_opena
  * owner 4 = 32
  */
 	encode_nfs4_seqid(xdr, arg->seqid);
-	encode_share_access(xdr, arg->fmode);
+	encode_share_access(xdr, arg->fmode, arg->open_flags);
 	p = reserve_space(xdr, 36);
 	p = xdr_encode_hyper(p, arg->clientid);
 	*p++ = cpu_to_be32(24);
@@ -1491,7 +1504,7 @@ static void encode_open_downgrade(struct xdr_stream *xdr, const struct nfs_close
 	encode_op_hdr(xdr, OP_OPEN_DOWNGRADE, decode_open_downgrade_maxsz, hdr);
 	encode_nfs4_stateid(xdr, arg->stateid);
 	encode_nfs4_seqid(xdr, arg->seqid);
-	encode_share_access(xdr, arg->fmode);
+	encode_share_access(xdr, arg->fmode, 0);
 }
 
 static void
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index b056b16..cf9db61 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -331,7 +331,8 @@ struct file_system_type nfs4_fs_type = {
 	.name		= "nfs4",
 	.mount		= nfs_fs_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE | FS_REVAL_DOT |
+			  FS_BINARY_MOUNTDATA | FS_DOES_SHARELOCK,
 };
 EXPORT_SYMBOL_GPL(nfs4_fs_type);
 
@@ -2589,6 +2590,8 @@ nfs_xdev_mount(struct file_system_type *fs_type, int flags,
 	struct nfs_server *server;
 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
+	/* save sharelock option */
+	int sharelock = data->sb->s_flags & MS_SHARELOCK;
 
 	dprintk("--> nfs_xdev_mount()\n");
 
@@ -2600,7 +2603,7 @@ nfs_xdev_mount(struct file_system_type *fs_type, int flags,
 	if (IS_ERR(server))
 		mntroot = ERR_CAST(server);
 	else
-		mntroot = nfs_fs_mount_common(server, flags,
+		mntroot = nfs_fs_mount_common(server, flags | sharelock,
 				dev_name, &mount_info, nfs_mod);
 
 	dprintk("<-- nfs_xdev_mount() = %ld\n",
-- 
1.8.1.5