[Qemu-devel] [RFC PATCH -V1 4/4] hw/9pfs: Add open flag to fid

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

We use this flag when we reopen the file. We need
to track open flag because if the open request have
flags like O_SYNC, we want to open the file with same flag
in host too

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 hw/9pfs/virtio-9p.c |   57 ++++++++++++++++++++++++++++++++++++++++++---------
 hw/9pfs/virtio-9p.h |    1 +
 2 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 1518e00..cbdf705 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -22,6 +22,8 @@
 int debug_9p_pdu;
 static void v9fs_reclaim_fd(V9fsState *s);
 
+#define PASS_OPEN_FLAG (O_SYNC | O_DSYNC | O_RSYNC |  \
+                        O_EXCL)
 enum {
     Oread   = 0x00,
     Owrite  = 0x01,
@@ -68,6 +70,24 @@ static int omode_to_uflags(int8_t mode)
     return ret;
 }
 
+static int get_dotl_openflags(int oflags)
+{
+    int flags;
+    /*
+     * Since we can share the fd between multiple fids,
+     * open the file in read write mode
+     */
+    flags = O_RDWR;
+    /*
+     * If the client asked for any of the below flags we
+     * should open the file with same open flag
+     */
+    if (oflags & PASS_OPEN_FLAG) {
+        flags =  oflags & PASS_OPEN_FLAG;
+    }
+    return flags;
+}
+
 void cred_init(FsCred *credp)
 {
     credp->fc_uid = -1;
@@ -452,9 +472,9 @@ static V9fsFidState *lookup_fid(V9fsState *s, int32_t fid)
              * descriptors.
              */
             if (f->fsmap.fid_type == P9_FID_FILE) {
-                /* FIXME!! should we remember the open flags ?*/
                 if (f->fsmap.fs.fd == -1) {
-                    f->fsmap.fs.fd = v9fs_do_open(s, &f->fsmap.path, O_RDWR);
+                    f->fsmap.fs.fd = v9fs_do_open(s, &f->fsmap.path,
+                                                  f->fsmap.open_flags);
                 }
             }
             /*
@@ -1811,14 +1831,19 @@ static void v9fs_open_post_lstat(V9fsState *s, V9fsOpenState *vs, int err)
         v9fs_open_post_opendir(s, vs, err);
     } else {
         if (s->proto_version == V9FS_PROTO_2000L) {
-            flags = vs->mode;
-            flags &= ~(O_NOCTTY | O_ASYNC | O_CREAT);
-            /* Ignore direct disk access hint until the server supports it. */
-            flags &= ~O_DIRECT;
+            flags = get_dotl_openflags(vs->mode);
         } else {
             flags = omode_to_uflags(vs->mode);
         }
         vs->fidp->fsmap.fs.fd = v9fs_do_open(s, &vs->fidp->fsmap.path, flags);
+        vs->fidp->fsmap.open_flags = flags;
+        if (flags & O_EXCL) {
+            /*
+             * We let the host file system do O_EXCL check
+             * We should not reclaim such fd
+             */
+            vs->fidp->fsmap.flags  |= FID_NON_RECLAIMABLE;
+        }
         v9fs_open_post_open(s, vs, err);
     }
     return;
@@ -1937,11 +1962,22 @@ static void v9fs_lcreate(V9fsState *s, V9fsPDU *pdu)
     v9fs_string_sprintf(&vs->fullname, "%s/%s", vs->fidp->fsmap.path.data,
              vs->name.data);
 
-    /* Ignore direct disk access hint until the server supports it. */
-    flags &= ~O_DIRECT;
-
+    flags = get_dotl_openflags(flags);
     vs->fidp->fsmap.fs.fd = v9fs_do_open2(s, vs->fullname.data, vs->fidp->uid,
-            gid, flags, mode);
+                                          gid, flags, mode);
+    /*
+     * We don't want to recreate the in reclaim path. So remove
+     * create flag
+     */
+    flags &= ~O_CREAT;
+    vs->fidp->fsmap.open_flags = flags;
+    if (flags & O_EXCL) {
+        /*
+         * We let the host file system do O_EXCL check
+         * We should not reclaim such fd
+         */
+        vs->fidp->fsmap.flags  |= FID_NON_RECLAIMABLE;
+    }
     v9fs_lcreate_post_do_open2(s, vs, err);
     return;
 
@@ -2653,6 +2689,7 @@ static void v9fs_create_post_lstat(V9fsState *s, V9fsCreateState *vs, int err)
                                               -1,
                                               omode_to_uflags(vs->mode)|O_CREAT,
                                               vs->perm);
+        vs->fidp->fsmap.open_flags = omode_to_uflags(vs->mode);
         v9fs_create_post_open2(s, vs, err);
     }
 
diff --git a/hw/9pfs/virtio-9p.h b/hw/9pfs/virtio-9p.h
index b2cd24b..c3cb75e 100644
--- a/hw/9pfs/virtio-9p.h
+++ b/hw/9pfs/virtio-9p.h
@@ -196,6 +196,7 @@ typedef struct V9fsfidmap {
         DIR *dir;
         V9fsXattr xattr;
     } fs;
+    int open_flags;
     int fid_type;
     V9fsString path;
     int flags;
-- 
1.7.1