fuse: Use generic xattr ops

In preparation for posix acl support, rework fuse to use xattr handlers and
the generic setxattr/getxattr/listxattr callbacks.  Split the xattr code
out into it's own file, and promote symbols to module-global scope as
needed.

Functionally these changes have no impact, as fuse still uses a single
handler for all xattrs which uses the old callbacks.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile
index e95eeb4..448aa27 100644 (file)
--- a/fs/fuse/Makefile
+++ b/fs/fuse/Makefile
@@ -5,4 +5,4 @@
 obj-$(CONFIG_FUSE_FS) += fuse.o
 obj-$(CONFIG_CUSE) += cuse.o
 
-fuse-objs := dev.o dir.o file.o inode.o control.o
+fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index b87c9bc..7490db1 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <linux/namei.h>
 #include <linux/slab.h>
+#include <linux/xattr.h>
 
 static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx)
 {
@@ -634,7 +635,7 @@ static int fuse_symlink(struct inode *dir, struct dentry *entry,
        return create_new_entry(fc, &args, dir, entry, S_IFLNK);
 }
 
-static inline void fuse_update_ctime(struct inode *inode)
+void fuse_update_ctime(struct inode *inode)
 {
        if (!IS_NOCMTIME(inode)) {
                inode->i_ctime = current_fs_time(inode->i_sb);
@@ -1724,171 +1725,6 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
        return fuse_update_attributes(inode, stat, NULL, NULL);
 }
 
-static int fuse_setxattr(struct dentry *unused, struct inode *inode,
-                        const char *name, const void *value,
-                        size_t size, int flags)
-{
-       struct fuse_conn *fc = get_fuse_conn(inode);
-       FUSE_ARGS(args);
-       struct fuse_setxattr_in inarg;
-       int err;
-
-       if (fc->no_setxattr)
-               return -EOPNOTSUPP;
-
-       memset(&inarg, 0, sizeof(inarg));
-       inarg.size = size;
-       inarg.flags = flags;
-       args.in.h.opcode = FUSE_SETXATTR;
-       args.in.h.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[1].size = strlen(name) + 1;
-       args.in.args[1].value = name;
-       args.in.args[2].size = size;
-       args.in.args[2].value = value;
-       err = fuse_simple_request(fc, &args);
-       if (err == -ENOSYS) {
-               fc->no_setxattr = 1;
-               err = -EOPNOTSUPP;
-       }
-       if (!err) {
-               fuse_invalidate_attr(inode);
-               fuse_update_ctime(inode);
-       }
-       return err;
-}
-
-static ssize_t fuse_getxattr(struct dentry *entry, struct inode *inode,
-                            const char *name, void *value, size_t size)
-{
-       struct fuse_conn *fc = get_fuse_conn(inode);
-       FUSE_ARGS(args);
-       struct fuse_getxattr_in inarg;
-       struct fuse_getxattr_out outarg;
-       ssize_t ret;
-
-       if (fc->no_getxattr)
-               return -EOPNOTSUPP;
-
-       memset(&inarg, 0, sizeof(inarg));
-       inarg.size = size;
-       args.in.h.opcode = FUSE_GETXATTR;
-       args.in.h.nodeid = get_node_id(inode);
-       args.in.numargs = 2;
-       args.in.args[0].size = sizeof(inarg);
-       args.in.args[0].value = &inarg;
-       args.in.args[1].size = strlen(name) + 1;
-       args.in.args[1].value = name;
-       /* This is really two different operations rolled into one */
-       args.out.numargs = 1;
-       if (size) {
-               args.out.argvar = 1;
-               args.out.args[0].size = size;
-               args.out.args[0].value = value;
-       } else {
-               args.out.args[0].size = sizeof(outarg);
-               args.out.args[0].value = &outarg;
-       }
-       ret = fuse_simple_request(fc, &args);
-       if (!ret && !size)
-               ret = outarg.size;
-       if (ret == -ENOSYS) {
-               fc->no_getxattr = 1;
-               ret = -EOPNOTSUPP;
-       }
-       return ret;
-}
-
-static int fuse_verify_xattr_list(char *list, size_t size)
-{
-       size_t origsize = size;
-
-       while (size) {
-               size_t thislen = strnlen(list, size);
-
-               if (!thislen || thislen == size)
-                       return -EIO;
-
-               size -= thislen + 1;
-               list += thislen + 1;
-       }
-
-       return origsize;
-}
-
-static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
-{
-       struct inode *inode = d_inode(entry);
-       struct fuse_conn *fc = get_fuse_conn(inode);
-       FUSE_ARGS(args);
-       struct fuse_getxattr_in inarg;
-       struct fuse_getxattr_out outarg;
-       ssize_t ret;
-
-       if (!fuse_allow_current_process(fc))
-               return -EACCES;
-
-       if (fc->no_listxattr)
-               return -EOPNOTSUPP;
-
-       memset(&inarg, 0, sizeof(inarg));
-       inarg.size = size;
-       args.in.h.opcode = FUSE_LISTXATTR;
-       args.in.h.nodeid = get_node_id(inode);
-       args.in.numargs = 1;
-       args.in.args[0].size = sizeof(inarg);
-       args.in.args[0].value = &inarg;
-       /* This is really two different operations rolled into one */
-       args.out.numargs = 1;
-       if (size) {
-               args.out.argvar = 1;
-               args.out.args[0].size = size;
-               args.out.args[0].value = list;
-       } else {
-               args.out.args[0].size = sizeof(outarg);
-               args.out.args[0].value = &outarg;
-       }
-       ret = fuse_simple_request(fc, &args);
-       if (!ret && !size)
-               ret = outarg.size;
-       if (ret > 0 && size)
-               ret = fuse_verify_xattr_list(list, ret);
-       if (ret == -ENOSYS) {
-               fc->no_listxattr = 1;
-               ret = -EOPNOTSUPP;
-       }
-       return ret;
-}
-
-static int fuse_removexattr(struct dentry *entry, const char *name)
-{
-       struct inode *inode = d_inode(entry);
-       struct fuse_conn *fc = get_fuse_conn(inode);
-       FUSE_ARGS(args);
-       int err;
-
-       if (fc->no_removexattr)
-               return -EOPNOTSUPP;
-
-       args.in.h.opcode = FUSE_REMOVEXATTR;
-       args.in.h.nodeid = get_node_id(inode);
-       args.in.numargs = 1;
-       args.in.args[0].size = strlen(name) + 1;
-       args.in.args[0].value = name;
-       err = fuse_simple_request(fc, &args);
-       if (err == -ENOSYS) {
-               fc->no_removexattr = 1;
-               err = -EOPNOTSUPP;
-       }
-       if (!err) {
-               fuse_invalidate_attr(inode);
-               fuse_update_ctime(inode);
-       }
-       return err;
-}
-
 static const struct inode_operations fuse_dir_inode_operations = {
        .lookup         = fuse_lookup,
        .mkdir          = fuse_mkdir,
@@ -1903,10 +1739,10 @@ static const struct inode_operations fuse_dir_inode_operations = {
        .mknod          = fuse_mknod,
        .permission     = fuse_permission,
        .getattr        = fuse_getattr,
-       .setxattr       = fuse_setxattr,
-       .getxattr       = fuse_getxattr,
+       .setxattr       = generic_setxattr,
+       .getxattr       = generic_getxattr,
        .listxattr      = fuse_listxattr,
-       .removexattr    = fuse_removexattr,
+       .removexattr    = generic_removexattr,
 };
 
 static const struct file_operations fuse_dir_operations = {
@@ -1924,10 +1760,10 @@ static const struct inode_operations fuse_common_inode_operations = {
        .setattr        = fuse_setattr,
        .permission     = fuse_permission,
        .getattr        = fuse_getattr,
-       .setxattr       = fuse_setxattr,
-       .getxattr       = fuse_getxattr,
+       .setxattr       = generic_setxattr,
+       .getxattr       = generic_getxattr,
        .listxattr      = fuse_listxattr,
-       .removexattr    = fuse_removexattr,
+       .removexattr    = generic_removexattr,
 };
 
 static const struct inode_operations fuse_symlink_inode_operations = {
@@ -1935,10 +1771,10 @@ static const struct inode_operations fuse_symlink_inode_operations = {
        .get_link       = fuse_get_link,
        .readlink       = generic_readlink,
        .getattr        = fuse_getattr,
-       .setxattr       = fuse_setxattr,
-       .getxattr       = fuse_getxattr,
+       .setxattr       = generic_setxattr,
+       .getxattr       = generic_getxattr,
        .listxattr      = fuse_listxattr,
-       .removexattr    = fuse_removexattr,
+       .removexattr    = generic_removexattr,
 };
 
 void fuse_init_common(struct inode *inode)

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index d98d8cc..6db54d0 100644 (file)
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -902,6 +902,8 @@ int fuse_allow_current_process(struct fuse_conn *fc);
 
 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
 
+void fuse_update_ctime(struct inode *inode);
+
 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
                           struct file *file, bool *refreshed);
 
@@ -966,4 +968,7 @@ void fuse_set_initialized(struct fuse_conn *fc);
 void fuse_unlock_inode(struct inode *inode);
 void fuse_lock_inode(struct inode *inode);
 
+ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
+extern const struct xattr_handler *fuse_xattr_handlers[];
+
 #endif /* _FS_FUSE_I_H */

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 4e05b51..1e535f3 100644 (file)
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1071,6 +1071,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
        }
        sb->s_magic = FUSE_SUPER_MAGIC;
        sb->s_op = &fuse_super_operations;
+       sb->s_xattr = fuse_xattr_handlers;
        sb->s_maxbytes = MAX_LFS_FILESIZE;
        sb->s_time_gran = 1;
        sb->s_export_op = &fuse_export_operations;

diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c
new file mode 100644 (file)
index 0000000..e22980f
--- /dev/null
+++ b/fs/fuse/xattr.c
@@ -0,0 +1,203 @@
+/*
+ * FUSE: Filesystem in Userspace
+ * Copyright (C) 2001-2016  Miklos Szeredi <miklos@szeredi.hu>
+ *
+ * This program can be distributed under the terms of the GNU GPL.
+ * See the file COPYING.
+ */
+
+#include "fuse_i.h"
+
+#include <linux/xattr.h>
+
+static int fuse_setxattr(struct inode *inode, const char *name,
+                        const void *value, size_t size, int flags)
+{
+       struct fuse_conn *fc = get_fuse_conn(inode);
+       FUSE_ARGS(args);
+       struct fuse_setxattr_in inarg;
+       int err;
+
+       if (fc->no_setxattr)
+               return -EOPNOTSUPP;
+
+       memset(&inarg, 0, sizeof(inarg));
+       inarg.size = size;
+       inarg.flags = flags;
+       args.in.h.opcode = FUSE_SETXATTR;
+       args.in.h.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[1].size = strlen(name) + 1;
+       args.in.args[1].value = name;
+       args.in.args[2].size = size;
+       args.in.args[2].value = value;
+       err = fuse_simple_request(fc, &args);
+       if (err == -ENOSYS) {
+               fc->no_setxattr = 1;
+               err = -EOPNOTSUPP;
+       }
+       if (!err) {
+               fuse_invalidate_attr(inode);
+               fuse_update_ctime(inode);
+       }
+       return err;
+}
+
+static ssize_t fuse_getxattr(struct inode *inode, const char *name,
+                            void *value, size_t size)
+{
+       struct fuse_conn *fc = get_fuse_conn(inode);
+       FUSE_ARGS(args);
+       struct fuse_getxattr_in inarg;
+       struct fuse_getxattr_out outarg;
+       ssize_t ret;
+
+       if (fc->no_getxattr)
+               return -EOPNOTSUPP;
+
+       memset(&inarg, 0, sizeof(inarg));
+       inarg.size = size;
+       args.in.h.opcode = FUSE_GETXATTR;
+       args.in.h.nodeid = get_node_id(inode);
+       args.in.numargs = 2;
+       args.in.args[0].size = sizeof(inarg);
+       args.in.args[0].value = &inarg;
+       args.in.args[1].size = strlen(name) + 1;
+       args.in.args[1].value = name;
+       /* This is really two different operations rolled into one */
+       args.out.numargs = 1;
+       if (size) {
+               args.out.argvar = 1;
+               args.out.args[0].size = size;
+               args.out.args[0].value = value;
+       } else {
+               args.out.args[0].size = sizeof(outarg);
+               args.out.args[0].value = &outarg;
+       }
+       ret = fuse_simple_request(fc, &args);
+       if (!ret && !size)
+               ret = outarg.size;
+       if (ret == -ENOSYS) {
+               fc->no_getxattr = 1;
+               ret = -EOPNOTSUPP;
+       }
+       return ret;
+}
+
+static int fuse_verify_xattr_list(char *list, size_t size)
+{
+       size_t origsize = size;
+
+       while (size) {
+               size_t thislen = strnlen(list, size);
+
+               if (!thislen || thislen == size)
+                       return -EIO;
+
+               size -= thislen + 1;
+               list += thislen + 1;
+       }
+
+       return origsize;
+}
+
+ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
+{
+       struct inode *inode = d_inode(entry);
+       struct fuse_conn *fc = get_fuse_conn(inode);
+       FUSE_ARGS(args);
+       struct fuse_getxattr_in inarg;
+       struct fuse_getxattr_out outarg;
+       ssize_t ret;
+
+       if (!fuse_allow_current_process(fc))
+               return -EACCES;
+
+       if (fc->no_listxattr)
+               return -EOPNOTSUPP;
+
+       memset(&inarg, 0, sizeof(inarg));
+       inarg.size = size;
+       args.in.h.opcode = FUSE_LISTXATTR;
+       args.in.h.nodeid = get_node_id(inode);
+       args.in.numargs = 1;
+       args.in.args[0].size = sizeof(inarg);
+       args.in.args[0].value = &inarg;
+       /* This is really two different operations rolled into one */
+       args.out.numargs = 1;
+       if (size) {
+               args.out.argvar = 1;
+               args.out.args[0].size = size;
+               args.out.args[0].value = list;
+       } else {
+               args.out.args[0].size = sizeof(outarg);
+               args.out.args[0].value = &outarg;
+       }
+       ret = fuse_simple_request(fc, &args);
+       if (!ret && !size)
+               ret = outarg.size;
+       if (ret > 0 && size)
+               ret = fuse_verify_xattr_list(list, ret);
+       if (ret == -ENOSYS) {
+               fc->no_listxattr = 1;
+               ret = -EOPNOTSUPP;
+       }
+       return ret;
+}
+
+static int fuse_removexattr(struct inode *inode, const char *name)
+{
+       struct fuse_conn *fc = get_fuse_conn(inode);
+       FUSE_ARGS(args);
+       int err;
+
+       if (fc->no_removexattr)
+               return -EOPNOTSUPP;
+
+       args.in.h.opcode = FUSE_REMOVEXATTR;
+       args.in.h.nodeid = get_node_id(inode);
+       args.in.numargs = 1;
+       args.in.args[0].size = strlen(name) + 1;
+       args.in.args[0].value = name;
+       err = fuse_simple_request(fc, &args);
+       if (err == -ENOSYS) {
+               fc->no_removexattr = 1;
+               err = -EOPNOTSUPP;
+       }
+       if (!err) {
+               fuse_invalidate_attr(inode);
+               fuse_update_ctime(inode);
+       }
+       return err;
+}
+
+static int fuse_xattr_get(const struct xattr_handler *handler,
+                        struct dentry *dentry, struct inode *inode,
+                        const char *name, void *value, size_t size)
+{
+       return fuse_getxattr(inode, name, value, size);
+}
+
+static int fuse_xattr_set(const struct xattr_handler *handler,
+                         struct dentry *dentry, struct inode *inode,
+                         const char *name, const void *value, size_t size,
+                         int flags)
+{
+       if (!value)
+               return fuse_removexattr(inode, name);
+
+       return fuse_setxattr(inode, name, value, size, flags);
+}
+
+static const struct xattr_handler fuse_xattr_handler = {
+       .prefix = "",
+       .get    = fuse_xattr_get,
+       .set    = fuse_xattr_set,
+};
+
+const struct xattr_handler *fuse_xattr_handlers[] = {
+       &fuse_xattr_handler,
+       NULL
+};