[PATCH 48/52] virtio-fs: pass version table pointer to fuse

[Vivek Goyal]

From: Miklos Szeredi <mszer...@redhat.com>

Signed-off-by: Miklos Szeredi <mszer...@redhat.com>
---
 fs/fuse/fuse_i.h    | 12 ++++++++++++
 fs/fuse/inode.c     | 10 ++++++++++
 fs/fuse/virtio_fs.c |  2 ++
 3 files changed, 24 insertions(+)

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 30c7b4b56200..8a2604606d51 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -100,6 +100,12 @@ struct fuse_mount_data {
 
        /* fuse_dev pointer to fill in, should contain NULL on entry */
        void **fudptr;
+
+       /* version table length in bytes */
+       size_t vertab_len;
+
+       /* version table kernel address */
+       void *vertab_kaddr;
 };
 
 /* One forget request */
@@ -898,6 +904,12 @@ struct fuse_conn {
        struct list_head free_ranges;
 
        unsigned long nr_ranges;
+
+       /** Size of version table */
+       uint64_t version_table_size;
+
+       /** Shared version entry for each active inode */
+       s64 *version_table;
 };
 
 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 4d2d623e607f..1ab4df442390 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -52,6 +52,7 @@ MODULE_PARM_DESC(max_user_congthresh,
  "unprivileged user can set");
 
 #define FUSE_SUPER_MAGIC 0x65735546
+#define VERSION_TABLE_MAGIC 0x7265566465726853
 
 #define FUSE_DEFAULT_BLKSIZE 512
 
@@ -1215,6 +1216,15 @@ int fuse_fill_super_common(struct super_block *sb,
        fuse_conn_init(fc, sb->s_user_ns, mount_data->dax_dev,
                        mount_data->fiq_ops, mount_data->fiq_priv);
        fc->release = fuse_free_conn;
+       fc->version_table_size = mount_data->vertab_len / sizeof(s64);
+       fc->version_table = mount_data->vertab_kaddr;
+
+       if (fc->version_table[0] != VERSION_TABLE_MAGIC) {
+               pr_warn("bad version table magic: 0x%16llx\n",
+                       fc->version_table[0]);
+               fc->version_table_size = 0;
+               fc->version_table = NULL;
+       }
 
        if (mount_data->dax_dev) {
                err = fuse_dax_mem_range_init(fc, mount_data->dax_dev);
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 7d5b23455639..88b00055589b 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -1246,6 +1246,8 @@ static int virtio_fs_fill_super(struct super_block *sb, 
void *data,
        d.fiq_priv = fs;
        d.fudptr = (void **)&fs->vqs[2].fud;
        d.destroy = true; /* Send destroy request on unmount */
+       d.vertab_len = fs->vertab_len;
+       d.vertab_kaddr = fs->vertab_kaddr;
        err = fuse_fill_super_common(sb, &d);
 
        if (err < 0)
-- 
2.13.6