Fuse client needs to send additional information to file server when
it calls SETXATTR(system.posix_acl_access). Right now there is no extra
space in fuse_setxattr_in. So introduce a v2 of the structure which has
more space in it and can be used to send extra flags.

"struct fuse_setxattr_in_v2" is only used if file server opts-in for it using
flag FUSE_SETXATTR_V2 during feature negotiations.

Signed-off-by: Vivek Goyal <vgo...@redhat.com>
---
 fs/fuse/acl.c             |  2 +-
 fs/fuse/fuse_i.h          |  5 ++++-
 fs/fuse/inode.c           |  4 +++-
 fs/fuse/xattr.c           | 21 +++++++++++++++------
 include/uapi/linux/fuse.h | 10 ++++++++++
 5 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c
index e9c0f916349d..d31260a139d4 100644
--- a/fs/fuse/acl.c
+++ b/fs/fuse/acl.c
@@ -94,7 +94,7 @@ int fuse_set_acl(struct user_namespace *mnt_userns, struct 
inode *inode,
                        return ret;
                }
 
-               ret = fuse_setxattr(inode, name, value, size, 0);
+               ret = fuse_setxattr(inode, name, value, size, 0, 0);
                kfree(value);
        } else {
                ret = fuse_removexattr(inode, name);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 63d97a15ffde..d00bf0b9a38c 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -668,6 +668,9 @@ struct fuse_conn {
        /** Is setxattr not implemented by fs? */
        unsigned no_setxattr:1;
 
+       /** Does file server support setxattr_v2 */
+       unsigned setxattr_v2:1;
+
        /** Is getxattr not implemented by fs? */
        unsigned no_getxattr:1;
 
@@ -1170,7 +1173,7 @@ void fuse_unlock_inode(struct inode *inode, bool locked);
 bool fuse_lock_inode(struct inode *inode);
 
 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
-                 size_t size, int flags);
+                 size_t size, int flags, unsigned extra_flags);
 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
                      size_t size);
 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index b0e18b470e91..1c726df13f80 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1052,6 +1052,8 @@ static void process_init_reply(struct fuse_mount *fm, 
struct fuse_args *args,
                                fc->handle_killpriv_v2 = 1;
                                fm->sb->s_flags |= SB_NOSEC;
                        }
+                       if (arg->flags & FUSE_SETXATTR_V2)
+                               fc->setxattr_v2 = 1;
                } else {
                        ra_pages = fc->max_read / PAGE_SIZE;
                        fc->no_lock = 1;
@@ -1095,7 +1097,7 @@ void fuse_send_init(struct fuse_mount *fm)
                FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
                FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS |
                FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA |
-               FUSE_HANDLE_KILLPRIV_V2;
+               FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_V2;
 #ifdef CONFIG_FUSE_DAX
        if (fm->fc->dax)
                ia->in.flags |= FUSE_MAP_ALIGNMENT;
diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c
index 1a7d7ace54e1..f2aae72653dc 100644
--- a/fs/fuse/xattr.c
+++ b/fs/fuse/xattr.c
@@ -12,24 +12,33 @@
 #include <linux/posix_acl_xattr.h>
 
 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
-                 size_t size, int flags)
+                 size_t size, int flags, unsigned extra_flags)
 {
        struct fuse_mount *fm = get_fuse_mount(inode);
        FUSE_ARGS(args);
        struct fuse_setxattr_in inarg;
+       struct fuse_setxattr_in_v2 inarg_v2;
+       bool setxattr_v2 = fm->fc->setxattr_v2;
        int err;
 
        if (fm->fc->no_setxattr)
                return -EOPNOTSUPP;
 
        memset(&inarg, 0, sizeof(inarg));
-       inarg.size = size;
-       inarg.flags = flags;
+       memset(&inarg_v2, 0, sizeof(inarg_v2));
+       if (setxattr_v2) {
+               inarg_v2.size = size;
+               inarg_v2.flags = flags;
+               inarg_v2.setxattr_flags = extra_flags;
+       } else {
+               inarg.size = size;
+               inarg.flags = flags;
+       }
        args.opcode = FUSE_SETXATTR;
        args.nodeid = get_node_id(inode);
        args.in_numargs = 3;
-       args.in_args[0].size = sizeof(inarg);
-       args.in_args[0].value = &inarg;
+       args.in_args[0].size = setxattr_v2 ? sizeof(inarg_v2) : sizeof(inarg);
+       args.in_args[0].value = setxattr_v2 ? &inarg_v2 : (void *)&inarg;
        args.in_args[1].size = strlen(name) + 1;
        args.in_args[1].value = name;
        args.in_args[2].size = size;
@@ -199,7 +208,7 @@ static int fuse_xattr_set(const struct xattr_handler 
*handler,
        if (!value)
                return fuse_removexattr(inode, name);
 
-       return fuse_setxattr(inode, name, value, size, flags);
+       return fuse_setxattr(inode, name, value, size, flags, 0);
 }
 
 static bool no_xattr_list(struct dentry *dentry)
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index 54442612c48b..1bb555c1c117 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -179,6 +179,7 @@
  *  7.33
  *  - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID
  *  - add FUSE_OPEN_KILL_SUIDGID
+ *  - add FUSE_SETXATTR_V2
  */
 
 #ifndef _LINUX_FUSE_H
@@ -330,6 +331,7 @@ struct fuse_file_lock {
  *                     does not have CAP_FSETID. Additionally upon
  *                     write/truncate sgid is killed only if file has group
  *                     execute permission. (Same as Linux VFS behavior).
+ * FUSE_SETXATTR_V2:   Does file server support V2 of struct fuse_setxattr_in
  */
 #define FUSE_ASYNC_READ                (1 << 0)
 #define FUSE_POSIX_LOCKS       (1 << 1)
@@ -360,6 +362,7 @@ struct fuse_file_lock {
 #define FUSE_MAP_ALIGNMENT     (1 << 26)
 #define FUSE_SUBMOUNTS         (1 << 27)
 #define FUSE_HANDLE_KILLPRIV_V2        (1 << 28)
+#define FUSE_SETXATTR_V2       (1 << 29)
 
 /**
  * CUSE INIT request/reply flags
@@ -686,6 +689,13 @@ struct fuse_setxattr_in {
        uint32_t        flags;
 };
 
+struct fuse_setxattr_in_v2 {
+       uint32_t        size;
+       uint32_t        flags;
+       uint32_t        setxattr_flags;
+       uint32_t        padding;
+};
+
 struct fuse_getxattr_in {
        uint32_t        size;
        uint32_t        padding;
-- 
2.25.4

Reply via email to