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Subject[095/244] fs/9p: Add OS dependent open flags in 9p protocol
3.0-stable review patch.  If anyone has any objections, please let us know.

------------------

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

commit f88657ce3f9713a0c62101dffb0e972a979e77b9 upstream.

Some of the flags are OS/arch dependent we add a 9p
protocol value which maps to asm-generic/fcntl.h values in Linux
Based on the original patch from Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>

[extra comments from author as to why this needs to go to stable:

Earlier for different operation such as open we used the values of open
flag as defined by the OS. But some of these flags such as O_DIRECT are
arch dependent. So if we have the 9p client and server running on
different architectures, we end up with client sending client
architecture value of these open flag and server will try to map these
values to what its architecture states. For ex: O_DIRECT on a x86 client
maps to

#define O_DIRECT 00040000

Where as on sparc server it will maps to

#define O_DIRECT 0x100000

Hence we need to map these open flags to OS/arch independent flag
values. Getting these changes to an early version of kernel ensures us
that we work with different combination of client and server. We should
ideally backport this patch to all possible kernel version.]

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/9p/v9fs_vfs.h | 2 +
fs/9p/vfs_file.c | 2 -
fs/9p/vfs_inode_dotl.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++-
include/net/9p/9p.h | 24 +++++++++++++++++++++
4 files changed, 81 insertions(+), 2 deletions(-)

--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -82,4 +82,6 @@ static inline void v9fs_invalidate_inode
v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
return;
}
+
+int v9fs_open_to_dotl_flags(int flags);
#endif
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -65,7 +65,7 @@ int v9fs_file_open(struct inode *inode,
v9inode = V9FS_I(inode);
v9ses = v9fs_inode2v9ses(inode);
if (v9fs_proto_dotl(v9ses))
- omode = file->f_flags;
+ omode = v9fs_open_to_dotl_flags(file->f_flags);
else
omode = v9fs_uflags2omode(file->f_flags,
v9fs_proto_dotu(v9ses));
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -191,6 +191,58 @@ v9fs_inode_from_fid_dotl(struct v9fs_ses
return inode;
}

+struct dotl_openflag_map {
+ int open_flag;
+ int dotl_flag;
+};
+
+static int v9fs_mapped_dotl_flags(int flags)
+{
+ int i;
+ int rflags = 0;
+ struct dotl_openflag_map dotl_oflag_map[] = {
+ { O_CREAT, P9_DOTL_CREATE },
+ { O_EXCL, P9_DOTL_EXCL },
+ { O_NOCTTY, P9_DOTL_NOCTTY },
+ { O_TRUNC, P9_DOTL_TRUNC },
+ { O_APPEND, P9_DOTL_APPEND },
+ { O_NONBLOCK, P9_DOTL_NONBLOCK },
+ { O_DSYNC, P9_DOTL_DSYNC },
+ { FASYNC, P9_DOTL_FASYNC },
+ { O_DIRECT, P9_DOTL_DIRECT },
+ { O_LARGEFILE, P9_DOTL_LARGEFILE },
+ { O_DIRECTORY, P9_DOTL_DIRECTORY },
+ { O_NOFOLLOW, P9_DOTL_NOFOLLOW },
+ { O_NOATIME, P9_DOTL_NOATIME },
+ { O_CLOEXEC, P9_DOTL_CLOEXEC },
+ { O_SYNC, P9_DOTL_SYNC},
+ };
+ for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) {
+ if (flags & dotl_oflag_map[i].open_flag)
+ rflags |= dotl_oflag_map[i].dotl_flag;
+ }
+ return rflags;
+}
+
+/**
+ * v9fs_open_to_dotl_flags- convert Linux specific open flags to
+ * plan 9 open flag.
+ * @flags: flags to convert
+ */
+int v9fs_open_to_dotl_flags(int flags)
+{
+ int rflags = 0;
+
+ /*
+ * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY
+ * and P9_DOTL_NOACCESS
+ */
+ rflags |= flags & O_ACCMODE;
+ rflags |= v9fs_mapped_dotl_flags(flags);
+
+ return rflags;
+}
+
/**
* v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
* @dir: directory inode that is being created
@@ -259,7 +311,8 @@ v9fs_vfs_create_dotl(struct inode *dir,
"Failed to get acl values in creat %d\n", err);
goto error;
}
- err = p9_client_create_dotl(ofid, name, flags, mode, gid, &qid);
+ err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
+ mode, gid, &qid);
if (err < 0) {
P9_DPRINTK(P9_DEBUG_VFS,
"p9_client_open_dotl failed in creat %d\n",
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -278,6 +278,30 @@ enum p9_perm_t {
P9_DMSETVTX = 0x00010000,
};

+/* 9p2000.L open flags */
+#define P9_DOTL_RDONLY 00000000
+#define P9_DOTL_WRONLY 00000001
+#define P9_DOTL_RDWR 00000002
+#define P9_DOTL_NOACCESS 00000003
+#define P9_DOTL_CREATE 00000100
+#define P9_DOTL_EXCL 00000200
+#define P9_DOTL_NOCTTY 00000400
+#define P9_DOTL_TRUNC 00001000
+#define P9_DOTL_APPEND 00002000
+#define P9_DOTL_NONBLOCK 00004000
+#define P9_DOTL_DSYNC 00010000
+#define P9_DOTL_FASYNC 00020000
+#define P9_DOTL_DIRECT 00040000
+#define P9_DOTL_LARGEFILE 00100000
+#define P9_DOTL_DIRECTORY 00200000
+#define P9_DOTL_NOFOLLOW 00400000
+#define P9_DOTL_NOATIME 01000000
+#define P9_DOTL_CLOEXEC 02000000
+#define P9_DOTL_SYNC 04000000
+
+/* 9p2000.L at flags */
+#define P9_DOTL_AT_REMOVEDIR 0x200
+
/**
* enum p9_qid_t - QID types
* @P9_QTDIR: directory



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