On Thu, 21 Mar 2019 11:47:57 +0000 David Howells <[email protected]> wrote:
Very weak change log (none!). What is this fs_context, and why does it need to change? Each patch should hold its own as a stand alone, as git history shows a patch not a series, and the cover letters will get lost over time. -- Steve > Signed-off-by: David Howells <[email protected]> > cc: Steven Rostedt <[email protected]> > cc: Greg Kroah-Hartman <[email protected]> > --- > > fs/tracefs/inode.c | 180 > ++++++++++++++++++++++++---------------------------- > 1 file changed, 83 insertions(+), 97 deletions(-) > > diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c > index 7098c49f3693..7ba64f38931f 100644 > --- a/fs/tracefs/inode.c > +++ b/fs/tracefs/inode.c > @@ -16,12 +16,13 @@ > #include <linux/module.h> > #include <linux/fs.h> > #include <linux/mount.h> > +#include <linux/fs_context.h> > +#include <linux/fs_parser.h> > #include <linux/kobject.h> > #include <linux/namei.h> > #include <linux/tracefs.h> > #include <linux/fsnotify.h> > #include <linux/seq_file.h> > -#include <linux/parser.h> > #include <linux/magic.h> > #include <linux/slab.h> > > @@ -138,73 +139,62 @@ static struct inode *tracefs_get_inode(struct > super_block *sb) > return inode; > } > > -struct tracefs_mount_opts { > +struct tracefs_fs_info { > kuid_t uid; > kgid_t gid; > umode_t mode; > }; > > enum { > - Opt_uid, > Opt_gid, > Opt_mode, > - Opt_err > + Opt_uid, > }; > > -static const match_table_t tokens = { > - {Opt_uid, "uid=%u"}, > - {Opt_gid, "gid=%u"}, > - {Opt_mode, "mode=%o"}, > - {Opt_err, NULL} > +static const struct fs_parameter_spec tracefs_param_specs[] = { > + fsparam_u32 ("gid", Opt_gid), > + fsparam_u32oct ("mode", Opt_mode), > + fsparam_u32 ("uid", Opt_uid), > + {} > }; > > -struct tracefs_fs_info { > - struct tracefs_mount_opts mount_opts; > +static const struct fs_parameter_description tracefs_fs_parameters = { > + .name = "tracefs", > + .specs = tracefs_param_specs, > }; > > -static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts) > +static int tracefs_parse_param(struct fs_context *fc, struct fs_parameter > *param) > { > - substring_t args[MAX_OPT_ARGS]; > - int option; > - int token; > + struct tracefs_fs_info *opts = fc->s_fs_info; > + struct fs_parse_result result; > kuid_t uid; > kgid_t gid; > - char *p; > - > - opts->mode = TRACEFS_DEFAULT_MODE; > - > - while ((p = strsep(&data, ",")) != NULL) { > - if (!*p) > - continue; > - > - token = match_token(p, tokens, args); > - switch (token) { > - case Opt_uid: > - if (match_int(&args[0], &option)) > - return -EINVAL; > - uid = make_kuid(current_user_ns(), option); > - if (!uid_valid(uid)) > - return -EINVAL; > - opts->uid = uid; > - break; > - case Opt_gid: > - if (match_int(&args[0], &option)) > - return -EINVAL; > - gid = make_kgid(current_user_ns(), option); > - if (!gid_valid(gid)) > - return -EINVAL; > - opts->gid = gid; > - break; > - case Opt_mode: > - if (match_octal(&args[0], &option)) > - return -EINVAL; > - opts->mode = option & S_IALLUGO; > - break; > + int opt; > + > + opt = fs_parse(fc, &tracefs_fs_parameters, param, &result); > + if (opt < 0) > + return opt; > + > + switch (opt) { > + case Opt_uid: > + uid = make_kuid(current_user_ns(), result.uint_32); > + if (!uid_valid(uid)) > + return invalf(fc, "Unknown uid"); > + opts->uid = uid; > + break; > + case Opt_gid: > + gid = make_kgid(current_user_ns(), result.uint_32); > + if (!gid_valid(gid)) > + return invalf(fc, "Unknown gid"); > + opts->gid = gid; > + break; > + case Opt_mode: > + opts->mode = result.uint_32 & S_IALLUGO; > + break; > /* > * We might like to report bad mount options here; > * but traditionally tracefs has ignored all mount options > */ > - } > } > > return 0; > @@ -214,100 +204,96 @@ static int tracefs_apply_options(struct super_block > *sb) > { > struct tracefs_fs_info *fsi = sb->s_fs_info; > struct inode *inode = sb->s_root->d_inode; > - struct tracefs_mount_opts *opts = &fsi->mount_opts; > > inode->i_mode &= ~S_IALLUGO; > - inode->i_mode |= opts->mode; > + inode->i_mode |= fsi->mode; > > - inode->i_uid = opts->uid; > - inode->i_gid = opts->gid; > + inode->i_uid = fsi->uid; > + inode->i_gid = fsi->gid; > > return 0; > } > > -static int tracefs_remount(struct super_block *sb, int *flags, char *data) > +static int tracefs_reconfigure(struct fs_context *fc) > { > - int err; > - struct tracefs_fs_info *fsi = sb->s_fs_info; > + struct super_block *sb = fc->root->d_sb; > > sync_filesystem(sb); > - err = tracefs_parse_options(data, &fsi->mount_opts); > - if (err) > - goto fail; > - > - tracefs_apply_options(sb); > - > -fail: > - return err; > + return tracefs_apply_options(sb); > } > > static int tracefs_show_options(struct seq_file *m, struct dentry *root) > { > struct tracefs_fs_info *fsi = root->d_sb->s_fs_info; > - struct tracefs_mount_opts *opts = &fsi->mount_opts; > > - if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) > + if (!uid_eq(fsi->uid, GLOBAL_ROOT_UID)) > seq_printf(m, ",uid=%u", > - from_kuid_munged(&init_user_ns, opts->uid)); > - if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) > + from_kuid_munged(&init_user_ns, fsi->uid)); > + if (!gid_eq(fsi->gid, GLOBAL_ROOT_GID)) > seq_printf(m, ",gid=%u", > - from_kgid_munged(&init_user_ns, opts->gid)); > - if (opts->mode != TRACEFS_DEFAULT_MODE) > - seq_printf(m, ",mode=%o", opts->mode); > + from_kgid_munged(&init_user_ns, fsi->gid)); > + if (fsi->mode != TRACEFS_DEFAULT_MODE) > + seq_printf(m, ",mode=%o", fsi->mode); > > return 0; > } > > static const struct super_operations tracefs_super_operations = { > .statfs = simple_statfs, > - .remount_fs = tracefs_remount, > .show_options = tracefs_show_options, > }; > > -static int trace_fill_super(struct super_block *sb, void *data, int silent) > +static int tracefs_fill_super(struct super_block *sb, struct fs_context *fc) > { > static const struct tree_descr trace_files[] = {{""}}; > - struct tracefs_fs_info *fsi; > int err; > > - fsi = kzalloc(sizeof(struct tracefs_fs_info), GFP_KERNEL); > - sb->s_fs_info = fsi; > - if (!fsi) { > - err = -ENOMEM; > - goto fail; > - } > - > - err = tracefs_parse_options(data, &fsi->mount_opts); > + err = simple_fill_super(sb, TRACEFS_MAGIC, trace_files); > if (err) > - goto fail; > - > - err = simple_fill_super(sb, TRACEFS_MAGIC, trace_files); > - if (err) > - goto fail; > + return err; > > sb->s_op = &tracefs_super_operations; > + return tracefs_apply_options(sb); > +} > > - tracefs_apply_options(sb); > - > - return 0; > +static int tracefs_get_tree(struct fs_context *fc) > +{ > + return vfs_get_super(fc, vfs_get_single_reconf_super, > + tracefs_fill_super); > +} > > -fail: > - kfree(fsi); > - sb->s_fs_info = NULL; > - return err; > +static void tracefs_free_fc(struct fs_context *fc) > +{ > + kfree(fc->s_fs_info); > } > > -static struct dentry *trace_mount(struct file_system_type *fs_type, > - int flags, const char *dev_name, > - void *data) > +static const struct fs_context_operations tracefs_context_ops = { > + .free = tracefs_free_fc, > + .parse_param = tracefs_parse_param, > + .get_tree = tracefs_get_tree, > + .reconfigure = tracefs_reconfigure, > +}; > + > +static int tracefs_init_fs_context(struct fs_context *fc) > { > - return mount_single(fs_type, flags, data, trace_fill_super); > + struct tracefs_fs_info *fsi; > + > + fsi = kzalloc(sizeof(struct tracefs_fs_info), GFP_KERNEL); > + if (!fsi) > + return -ENOMEM; > + > + fsi->mode = TRACEFS_DEFAULT_MODE; > + > + fc->s_fs_info = fsi; > + fc->ops = &tracefs_context_ops; > + return 0; > } > > static struct file_system_type trace_fs_type = { > .owner = THIS_MODULE, > .name = "tracefs", > - .mount = trace_mount, > + .init_fs_context = tracefs_init_fs_context, > + .parameters = &tracefs_fs_parameters, > .kill_sb = kill_litter_super, > }; > MODULE_ALIAS_FS("tracefs");
