| Message ID | 20230605-fs-overlayfs-mount_api-v3-2-730d9646b27d@kernel.org (mailing list archive) |
|---|---|
| State | Under Review |
| Headers | show |
| Series | ovl: port to new mount api & updated layer parsing | expand |
On Tue, Jun 13, 2023 at 5:49 PM Christian Brauner <brauner@kernel.org> wrote: > > We recently ported util-linux to the new mount api. Now the mount(8) > tool will by default use the new mount api. While trying hard to fall > back to the old mount api gracefully there are still cases where we run > into issues that are difficult to handle nicely. > > Now with mount(8) and libmount supporting the new mount api I expect an > increase in the number of bug reports and issues we're going to see with > filesystems that don't yet support the new mount api. So it's time we > rectify this. > > Signed-off-by: Christian Brauner <brauner@kernel.org> > --- > fs/overlayfs/ovl_entry.h | 2 +- > fs/overlayfs/super.c | 557 ++++++++++++++++++++++++++--------------------- > 2 files changed, 305 insertions(+), 254 deletions(-) > > diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h > index e5207c4bf5b8..c72433c06006 100644 > --- a/fs/overlayfs/ovl_entry.h > +++ b/fs/overlayfs/ovl_entry.h > @@ -12,7 +12,7 @@ struct ovl_config { > bool default_permissions; > bool redirect_dir; > bool redirect_follow; > - const char *redirect_mode; > + unsigned redirect_mode; I have a separate patch to get rid of redirect_dir and redirect_follow leaving only redirect_mode enum. I've already rebased your patches over this change in my branch. https://github.com/amir73il/linux/commits/fs-overlayfs-mount_api > bool index; > bool uuid; > bool nfs_export; > diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c > index d9be5d318e1b..3392dc5d2082 100644 > --- a/fs/overlayfs/super.c > +++ b/fs/overlayfs/super.c > @@ -16,6 +16,8 @@ > #include <linux/posix_acl_xattr.h> > #include <linux/exportfs.h> > #include <linux/file.h> > +#include <linux/fs_context.h> > +#include <linux/fs_parser.h> > #include "overlayfs.h" > > MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); > @@ -59,6 +61,79 @@ module_param_named(metacopy, ovl_metacopy_def, bool, 0644); > MODULE_PARM_DESC(metacopy, > "Default to on or off for the metadata only copy up feature"); > > +enum { > + Opt_lowerdir, > + Opt_upperdir, > + Opt_workdir, > + Opt_default_permissions, > + Opt_redirect_dir, > + Opt_index, > + Opt_uuid, > + Opt_nfs_export, > + Opt_userxattr, > + Opt_xino, > + Opt_metacopy, > + Opt_volatile, > +}; Renaming all those enums to lower case creates unneeded churn. I undid that in my branch, so now the mount api porting patch is a lot smaller. > + > +static const struct constant_table ovl_parameter_bool[] = { > + { "on", true }, > + { "off", false }, > + {} > +}; > + > +static const struct constant_table ovl_parameter_xino[] = { > + { "on", OVL_XINO_ON }, > + { "off", OVL_XINO_OFF }, > + { "auto", OVL_XINO_AUTO }, > + {} > +}; > + > +enum { > + OVL_REDIRECT_DIR_ON, > + OVL_REDIRECT_DIR_OFF, > + OVL_REDIRECT_DIR_FOLLOW, > + OVL_REDIRECT_DIR_NOFOLLOW, > +}; > + > +static const struct constant_table ovl_parameter_redirect_dir[] = { > + { "on", OVL_REDIRECT_DIR_ON }, > + { "off", OVL_REDIRECT_DIR_OFF }, > + { "follow", OVL_REDIRECT_DIR_FOLLOW }, > + { "nofollow", OVL_REDIRECT_DIR_NOFOLLOW }, > + {} > +}; > + > +static const char *ovl_redirect_mode(struct ovl_config *config) > +{ > + return ovl_parameter_redirect_dir[config->redirect_mode].name; > +} > + > +static const struct fs_parameter_spec ovl_parameter_spec[] = { > + fsparam_string("lowerdir", Opt_lowerdir), > + fsparam_string("upperdir", Opt_upperdir), > + fsparam_string("workdir", Opt_workdir), > + fsparam_flag("default_permissions", Opt_default_permissions), > + fsparam_enum("redirect_dir", Opt_redirect_dir, ovl_parameter_redirect_dir), > + fsparam_enum("index", Opt_index, ovl_parameter_bool), > + fsparam_enum("uuid", Opt_uuid, ovl_parameter_bool), > + fsparam_enum("nfs_export", Opt_nfs_export, ovl_parameter_bool), > + fsparam_flag("userxattr", Opt_userxattr), > + fsparam_enum("xino", Opt_xino, ovl_parameter_xino), > + fsparam_enum("metacopy", Opt_metacopy, ovl_parameter_bool), > + fsparam_flag("volatile", Opt_volatile), > + {} > +}; > + > +#define OVL_METACOPY_SET BIT(0) > +#define OVL_REDIRECT_SET BIT(1) > +#define OVL_NFS_EXPORT_SET BIT(2) > +#define OVL_INDEX_SET BIT(3) > + > +struct ovl_fs_context { > + u8 set; > +}; > + > static struct dentry *ovl_d_real(struct dentry *dentry, > const struct inode *inode) > { > @@ -243,7 +318,6 @@ static void ovl_free_fs(struct ovl_fs *ofs) > kfree(ofs->config.lowerdir); > kfree(ofs->config.upperdir); > kfree(ofs->config.workdir); > - kfree(ofs->config.redirect_mode); > if (ofs->creator_cred) > put_cred(ofs->creator_cred); > kfree(ofs); > @@ -253,7 +327,8 @@ static void ovl_put_super(struct super_block *sb) > { > struct ovl_fs *ofs = sb->s_fs_info; > > - ovl_free_fs(ofs); > + if (ofs) > + ovl_free_fs(ofs); > } > > /* Sync real dirty inodes in upper filesystem (if it exists) */ > @@ -357,6 +432,7 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) > { > struct super_block *sb = dentry->d_sb; > struct ovl_fs *ofs = sb->s_fs_info; > + const char *redirect_mode; > > seq_show_option(m, "lowerdir", ofs->config.lowerdir); > if (ofs->config.upperdir) { > @@ -365,8 +441,9 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) > } > if (ofs->config.default_permissions) > seq_puts(m, ",default_permissions"); > - if (strcmp(ofs->config.redirect_mode, ovl_redirect_mode_def()) != 0) > - seq_printf(m, ",redirect_dir=%s", ofs->config.redirect_mode); > + redirect_mode = ovl_redirect_mode(&ofs->config); > + if (strcmp(redirect_mode, ovl_redirect_mode_def()) != 0) > + seq_printf(m, ",redirect_dir=%s", redirect_mode); > if (ofs->config.index != ovl_index_def) > seq_printf(m, ",index=%s", ofs->config.index ? "on" : "off"); > if (!ofs->config.uuid) > @@ -386,27 +463,6 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) > return 0; > } > > -static int ovl_remount(struct super_block *sb, int *flags, char *data) > -{ > - struct ovl_fs *ofs = sb->s_fs_info; > - struct super_block *upper_sb; > - int ret = 0; > - > - if (!(*flags & SB_RDONLY) && ovl_force_readonly(ofs)) > - return -EROFS; > - > - if (*flags & SB_RDONLY && !sb_rdonly(sb)) { > - upper_sb = ovl_upper_mnt(ofs)->mnt_sb; > - if (ovl_should_sync(ofs)) { > - down_read(&upper_sb->s_umount); > - ret = sync_filesystem(upper_sb); > - up_read(&upper_sb->s_umount); > - } > - } > - > - return ret; > -} Moving code around and changing it at the same time makes reviewing very hard. I undid the move in my patch. If you want to rearrange the functions in the file afterwards I don't mind. > - > static const struct super_operations ovl_super_operations = { > .alloc_inode = ovl_alloc_inode, > .free_inode = ovl_free_inode, > @@ -416,216 +472,42 @@ static const struct super_operations ovl_super_operations = { > .sync_fs = ovl_sync_fs, > .statfs = ovl_statfs, > .show_options = ovl_show_options, > - .remount_fs = ovl_remount, > -}; > - > -enum { > - OPT_LOWERDIR, > - OPT_UPPERDIR, > - OPT_WORKDIR, > - OPT_DEFAULT_PERMISSIONS, > - OPT_REDIRECT_DIR, > - OPT_INDEX_ON, > - OPT_INDEX_OFF, > - OPT_UUID_ON, > - OPT_UUID_OFF, > - OPT_NFS_EXPORT_ON, > - OPT_USERXATTR, > - OPT_NFS_EXPORT_OFF, > - OPT_XINO_ON, > - OPT_XINO_OFF, > - OPT_XINO_AUTO, > - OPT_METACOPY_ON, > - OPT_METACOPY_OFF, > - OPT_VOLATILE, > - OPT_ERR, > -}; > - > -static const match_table_t ovl_tokens = { > - {OPT_LOWERDIR, "lowerdir=%s"}, > - {OPT_UPPERDIR, "upperdir=%s"}, > - {OPT_WORKDIR, "workdir=%s"}, > - {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, > - {OPT_REDIRECT_DIR, "redirect_dir=%s"}, > - {OPT_INDEX_ON, "index=on"}, > - {OPT_INDEX_OFF, "index=off"}, > - {OPT_USERXATTR, "userxattr"}, > - {OPT_UUID_ON, "uuid=on"}, > - {OPT_UUID_OFF, "uuid=off"}, > - {OPT_NFS_EXPORT_ON, "nfs_export=on"}, > - {OPT_NFS_EXPORT_OFF, "nfs_export=off"}, > - {OPT_XINO_ON, "xino=on"}, > - {OPT_XINO_OFF, "xino=off"}, > - {OPT_XINO_AUTO, "xino=auto"}, > - {OPT_METACOPY_ON, "metacopy=on"}, > - {OPT_METACOPY_OFF, "metacopy=off"}, > - {OPT_VOLATILE, "volatile"}, > - {OPT_ERR, NULL} > }; > > -static char *ovl_next_opt(char **s) > +static int ovl_set_redirect_mode(struct ovl_config *config) > { > - char *sbegin = *s; > - char *p; > - > - if (sbegin == NULL) > - return NULL; > - > - for (p = sbegin; *p; p++) { > - if (*p == '\\') { > - p++; > - if (!*p) > - break; > - } else if (*p == ',') { > - *p = '\0'; > - *s = p + 1; > - return sbegin; > - } > - } > - *s = NULL; > - return sbegin; > -} > - > -static int ovl_parse_redirect_mode(struct ovl_config *config, const char *mode) > -{ > - if (strcmp(mode, "on") == 0) { > + switch (config->redirect_mode) { > + case OVL_REDIRECT_DIR_ON: > config->redirect_dir = true; > /* > * Does not make sense to have redirect creation without > * redirect following. > */ > config->redirect_follow = true; > - } else if (strcmp(mode, "follow") == 0) { > + return 0; > + case OVL_REDIRECT_DIR_FOLLOW: > config->redirect_follow = true; > - } else if (strcmp(mode, "off") == 0) { > + return 0; > + case OVL_REDIRECT_DIR_OFF: > if (ovl_redirect_always_follow) > config->redirect_follow = true; > - } else if (strcmp(mode, "nofollow") != 0) { > - pr_err("bad mount option \"redirect_dir=%s\"\n", > - mode); > - return -EINVAL; > + return 0; > + case OVL_REDIRECT_DIR_NOFOLLOW: > + return 0; > } > > - return 0; > + pr_err("invalid \"redirect_dir\" mount option\n"); > + return -EINVAL; > } > > -static int ovl_parse_opt(char *opt, struct ovl_config *config) > +static int ovl_fs_params_verify(const struct ovl_fs_context *ctx, > + struct ovl_config *config) > { > - char *p; > int err; > - bool metacopy_opt = false, redirect_opt = false; > - bool nfs_export_opt = false, index_opt = false; > - > - config->redirect_mode = kstrdup(ovl_redirect_mode_def(), GFP_KERNEL); > - if (!config->redirect_mode) > - return -ENOMEM; > - > - while ((p = ovl_next_opt(&opt)) != NULL) { > - int token; > - substring_t args[MAX_OPT_ARGS]; > - > - if (!*p) > - continue; > - > - token = match_token(p, ovl_tokens, args); > - switch (token) { > - case OPT_UPPERDIR: > - kfree(config->upperdir); > - config->upperdir = match_strdup(&args[0]); > - if (!config->upperdir) > - return -ENOMEM; > - break; > - > - case OPT_LOWERDIR: > - kfree(config->lowerdir); > - config->lowerdir = match_strdup(&args[0]); > - if (!config->lowerdir) > - return -ENOMEM; > - break; > - > - case OPT_WORKDIR: > - kfree(config->workdir); > - config->workdir = match_strdup(&args[0]); > - if (!config->workdir) > - return -ENOMEM; > - break; > - > - case OPT_DEFAULT_PERMISSIONS: > - config->default_permissions = true; > - break; > - > - case OPT_REDIRECT_DIR: > - kfree(config->redirect_mode); > - config->redirect_mode = match_strdup(&args[0]); > - if (!config->redirect_mode) > - return -ENOMEM; > - redirect_opt = true; > - break; > - > - case OPT_INDEX_ON: > - config->index = true; > - index_opt = true; > - break; > - > - case OPT_INDEX_OFF: > - config->index = false; > - index_opt = true; > - break; > - > - case OPT_UUID_ON: > - config->uuid = true; > - break; > - > - case OPT_UUID_OFF: > - config->uuid = false; > - break; > - > - case OPT_NFS_EXPORT_ON: > - config->nfs_export = true; > - nfs_export_opt = true; > - break; > - > - case OPT_NFS_EXPORT_OFF: > - config->nfs_export = false; > - nfs_export_opt = true; > - break; > - > - case OPT_XINO_ON: > - config->xino = OVL_XINO_ON; > - break; > - > - case OPT_XINO_OFF: > - config->xino = OVL_XINO_OFF; > - break; > - > - case OPT_XINO_AUTO: > - config->xino = OVL_XINO_AUTO; > - break; > - > - case OPT_METACOPY_ON: > - config->metacopy = true; > - metacopy_opt = true; > - break; > - > - case OPT_METACOPY_OFF: > - config->metacopy = false; > - metacopy_opt = true; > - break; > - > - case OPT_VOLATILE: > - config->ovl_volatile = true; > - break; > - > - case OPT_USERXATTR: > - config->userxattr = true; > - break; > - > - default: > - pr_err("unrecognized mount option \"%s\" or missing value\n", > - p); > - return -EINVAL; > - } > - } > + bool metacopy_opt = ctx->set & OVL_METACOPY_SET; > + bool redirect_opt = ctx->set & OVL_REDIRECT_SET; > + bool nfs_export_opt = ctx->set & OVL_NFS_EXPORT_SET; > + bool index_opt = ctx->set & OVL_INDEX_SET; > > /* Workdir/index are useless in non-upper mount */ > if (!config->upperdir) { > @@ -647,7 +529,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) > config->ovl_volatile = false; > } > > - err = ovl_parse_redirect_mode(config, config->redirect_mode); > + err = ovl_set_redirect_mode(config); > if (err) > return err; > > @@ -662,7 +544,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) > if (config->metacopy && !config->redirect_dir) { > if (metacopy_opt && redirect_opt) { > pr_err("conflicting options: metacopy=on,redirect_dir=%s\n", > - config->redirect_mode); > + ovl_redirect_mode(config)); > return -EINVAL; > } > if (redirect_opt) { > @@ -671,7 +553,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) > * in this conflict. > */ > pr_info("disabling metacopy due to redirect_dir=%s\n", > - config->redirect_mode); > + ovl_redirect_mode(config)); > config->metacopy = false; > } else { > /* Automatically enable redirect otherwise. */ > @@ -728,7 +610,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) > if (config->userxattr) { > if (config->redirect_follow && redirect_opt) { > pr_err("conflicting options: userxattr,redirect_dir=%s\n", > - config->redirect_mode); > + ovl_redirect_mode(config)); > return -EINVAL; > } > if (config->metacopy && metacopy_opt) { > @@ -1926,12 +1808,128 @@ static struct dentry *ovl_get_root(struct super_block *sb, > return root; > } > > -static int ovl_fill_super(struct super_block *sb, void *data, int silent) > +static int ovl_parse_param(struct fs_context *fc, struct fs_parameter *param) > +{ > + int err = 0; > + struct fs_parse_result result; > + struct ovl_fs *ofs = fc->s_fs_info; > + struct ovl_config *config = &ofs->config; > + struct ovl_fs_context *ctx = fc->fs_private; > + char *dup; > + int opt; > + > + /* > + * On remount overlayfs has always ignored all mount options no > + * matter if malformed or not so for backwards compatibility we > + * do the same here. > + */ > + if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) > + return 0; > + > + opt = fs_parse(fc, ovl_parameter_spec, param, &result); > + if (opt < 0) > + return opt; > + > + switch (opt) { > + case Opt_lowerdir: > + dup = kstrdup(param->string, GFP_KERNEL); > + if (!dup) { > + err = -ENOMEM; > + break; > + } > + > + kfree(config->lowerdir); > + config->lowerdir = dup; > + break; > + case Opt_upperdir: > + dup = kstrdup(param->string, GFP_KERNEL); > + if (!dup) { > + err = -ENOMEM; > + break; > + } > + > + kfree(config->upperdir); > + config->upperdir = dup; > + break; > + case Opt_workdir: > + dup = kstrdup(param->string, GFP_KERNEL); > + if (!dup) { > + err = -ENOMEM; > + break; > + } > + > + kfree(config->workdir); > + config->workdir = dup; > + break; > + case Opt_default_permissions: > + config->default_permissions = true; > + break; > + case Opt_index: > + config->index = result.uint_32; > + ctx->set |= OVL_INDEX_SET; > + break; > + case Opt_uuid: > + config->uuid = result.uint_32; > + break; > + case Opt_nfs_export: > + config->nfs_export = result.uint_32; > + ctx->set |= OVL_NFS_EXPORT_SET; > + break; > + case Opt_metacopy: > + config->metacopy = result.uint_32; > + ctx->set |= OVL_METACOPY_SET; > + break; > + case Opt_userxattr: > + config->userxattr = true; > + break; > + case Opt_volatile: > + config->ovl_volatile = true; > + break; > + case Opt_xino: > + config->xino = result.uint_32; > + break; > + case Opt_redirect_dir: > + config->redirect_mode = result.uint_32; > + ctx->set |= OVL_REDIRECT_SET; > + break; > + default: > + pr_err("unrecognized mount option \"%s\" or missing value\n", param->key); > + return -EINVAL; > + } > + > + return err; > +} > + > + > +static int ovl_reconfigure(struct fs_context *fc) > { > - struct path upperpath = { }; > + struct super_block *sb = fc->root->d_sb; > + struct ovl_fs *ofs = sb->s_fs_info; > + struct super_block *upper_sb; > + int ret = 0; > + > + if (!(fc->sb_flags & SB_RDONLY) && ovl_force_readonly(ofs)) > + return -EROFS; > + > + if (fc->sb_flags & SB_RDONLY && !sb_rdonly(sb)) { > + upper_sb = ovl_upper_mnt(ofs)->mnt_sb; > + if (ovl_should_sync(ofs)) { > + down_read(&upper_sb->s_umount); > + ret = sync_filesystem(upper_sb); > + up_read(&upper_sb->s_umount); > + } > + } > + > + return ret; > +} > + > +static int ovl_fill_super(struct super_block *sb, struct fs_context *fc) > +{ > + struct ovl_fs *ofs = sb->s_fs_info; > + struct ovl_fs_context *ctx = fc->fs_private; > + struct path upperpath = {}; > struct dentry *root_dentry; > struct ovl_entry *oe; > - struct ovl_fs *ofs; > struct ovl_layer *layers; > struct cred *cred; > char *splitlower = NULL; > @@ -1939,36 +1937,24 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) > int err; > > err = -EIO; > - if (WARN_ON(sb->s_user_ns != current_user_ns())) > - goto out; > + if (WARN_ON(fc->user_ns != current_user_ns())) > + goto out_err; > > + ofs->share_whiteout = true; > sb->s_d_op = &ovl_dentry_operations; > > - err = -ENOMEM; > - ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); > - if (!ofs) > - goto out; > - > err = -ENOMEM; > ofs->creator_cred = cred = prepare_creds(); > if (!cred) > goto out_err; > > - /* Is there a reason anyone would want not to share whiteouts? */ > - ofs->share_whiteout = true; > - > - ofs->config.index = ovl_index_def; > - ofs->config.uuid = true; > - ofs->config.nfs_export = ovl_nfs_export_def; > - ofs->config.xino = ovl_xino_def(); > - ofs->config.metacopy = ovl_metacopy_def; > - err = ovl_parse_opt((char *) data, &ofs->config); > + err = ovl_fs_params_verify(ctx, &ofs->config); > if (err) > goto out_err; > > err = -EINVAL; > if (!ofs->config.lowerdir) { > - if (!silent) > + if (fc->sb_flags & SB_SILENT) Test is negated here. I fixed it in my branch. No need to re-send. > pr_err("missing 'lowerdir'\n"); > goto out_err; > } > @@ -2113,25 +2099,90 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) > out_free_oe: > ovl_free_entry(oe); > out_err: > - kfree(splitlower); > - path_put(&upperpath); > - ovl_free_fs(ofs); > -out: Folded your fix here: ovl_free_fs(ofs); sb->s_fs_info = NULL; > return err; > } > Thanks, Amir.
On Fri, Jun 16, 2023 at 04:21:29PM +0300, Amir Goldstein wrote: > On Tue, Jun 13, 2023 at 5:49 PM Christian Brauner <brauner@kernel.org> wrote: > > > > We recently ported util-linux to the new mount api. Now the mount(8) > > tool will by default use the new mount api. While trying hard to fall > > back to the old mount api gracefully there are still cases where we run > > into issues that are difficult to handle nicely. > > > > Now with mount(8) and libmount supporting the new mount api I expect an > > increase in the number of bug reports and issues we're going to see with > > filesystems that don't yet support the new mount api. So it's time we > > rectify this. > > > > Signed-off-by: Christian Brauner <brauner@kernel.org> > > --- > > fs/overlayfs/ovl_entry.h | 2 +- > > fs/overlayfs/super.c | 557 ++++++++++++++++++++++++++--------------------- > > 2 files changed, 305 insertions(+), 254 deletions(-) > > > > diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h > > index e5207c4bf5b8..c72433c06006 100644 > > --- a/fs/overlayfs/ovl_entry.h > > +++ b/fs/overlayfs/ovl_entry.h > > @@ -12,7 +12,7 @@ struct ovl_config { > > bool default_permissions; > > bool redirect_dir; > > bool redirect_follow; > > - const char *redirect_mode; > > + unsigned redirect_mode; > > I have a separate patch to get rid of redirect_dir and redirect_follow > leaving only redirect_mode enum. > > I've already rebased your patches over this change in my branch. > > https://github.com/amir73il/linux/commits/fs-overlayfs-mount_api > > > > bool index; > > bool uuid; > > bool nfs_export; > > diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c > > index d9be5d318e1b..3392dc5d2082 100644 > > --- a/fs/overlayfs/super.c > > +++ b/fs/overlayfs/super.c > > @@ -16,6 +16,8 @@ > > #include <linux/posix_acl_xattr.h> > > #include <linux/exportfs.h> > > #include <linux/file.h> > > +#include <linux/fs_context.h> > > +#include <linux/fs_parser.h> > > #include "overlayfs.h" > > > > MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); > > @@ -59,6 +61,79 @@ module_param_named(metacopy, ovl_metacopy_def, bool, 0644); > > MODULE_PARM_DESC(metacopy, > > "Default to on or off for the metadata only copy up feature"); > > > > +enum { > > + Opt_lowerdir, > > + Opt_upperdir, > > + Opt_workdir, > > + Opt_default_permissions, > > + Opt_redirect_dir, > > + Opt_index, > > + Opt_uuid, > > + Opt_nfs_export, > > + Opt_userxattr, > > + Opt_xino, > > + Opt_metacopy, > > + Opt_volatile, > > +}; > > Renaming all those enums to lower case creates unneeded churn. > I undid that in my branch, so now the mount api porting patch is a > lot smaller. Every single filesystem apart from fuse and overlayfs uses the standard "Opt_" syntax. Only fuse and overlayfs use OPT_* all uppercase. Even the documenation uses Opt_* throughout. So I'd appreciate it if you please did not go out of your way to deviate from this. I already did the work to convert to the Opt_* format on purpose. If you want less churn however, then you can ofc move this to a preparatory patch that converts to the standard format.
On Fri, Jun 16, 2023 at 4:28 PM Christian Brauner <brauner@kernel.org> wrote: > > On Fri, Jun 16, 2023 at 04:21:29PM +0300, Amir Goldstein wrote: > > On Tue, Jun 13, 2023 at 5:49 PM Christian Brauner <brauner@kernel.org> wrote: > > > > > > We recently ported util-linux to the new mount api. Now the mount(8) > > > tool will by default use the new mount api. While trying hard to fall > > > back to the old mount api gracefully there are still cases where we run > > > into issues that are difficult to handle nicely. > > > > > > Now with mount(8) and libmount supporting the new mount api I expect an > > > increase in the number of bug reports and issues we're going to see with > > > filesystems that don't yet support the new mount api. So it's time we > > > rectify this. > > > > > > Signed-off-by: Christian Brauner <brauner@kernel.org> > > > --- > > > fs/overlayfs/ovl_entry.h | 2 +- > > > fs/overlayfs/super.c | 557 ++++++++++++++++++++++++++--------------------- > > > 2 files changed, 305 insertions(+), 254 deletions(-) > > > > > > diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h > > > index e5207c4bf5b8..c72433c06006 100644 > > > --- a/fs/overlayfs/ovl_entry.h > > > +++ b/fs/overlayfs/ovl_entry.h > > > @@ -12,7 +12,7 @@ struct ovl_config { > > > bool default_permissions; > > > bool redirect_dir; > > > bool redirect_follow; > > > - const char *redirect_mode; > > > + unsigned redirect_mode; > > > > I have a separate patch to get rid of redirect_dir and redirect_follow > > leaving only redirect_mode enum. > > > > I've already rebased your patches over this change in my branch. > > > > https://github.com/amir73il/linux/commits/fs-overlayfs-mount_api > > > > > > > bool index; > > > bool uuid; > > > bool nfs_export; > > > diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c > > > index d9be5d318e1b..3392dc5d2082 100644 > > > --- a/fs/overlayfs/super.c > > > +++ b/fs/overlayfs/super.c > > > @@ -16,6 +16,8 @@ > > > #include <linux/posix_acl_xattr.h> > > > #include <linux/exportfs.h> > > > #include <linux/file.h> > > > +#include <linux/fs_context.h> > > > +#include <linux/fs_parser.h> > > > #include "overlayfs.h" > > > > > > MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); > > > @@ -59,6 +61,79 @@ module_param_named(metacopy, ovl_metacopy_def, bool, 0644); > > > MODULE_PARM_DESC(metacopy, > > > "Default to on or off for the metadata only copy up feature"); > > > > > > +enum { > > > + Opt_lowerdir, > > > + Opt_upperdir, > > > + Opt_workdir, > > > + Opt_default_permissions, > > > + Opt_redirect_dir, > > > + Opt_index, > > > + Opt_uuid, > > > + Opt_nfs_export, > > > + Opt_userxattr, > > > + Opt_xino, > > > + Opt_metacopy, > > > + Opt_volatile, > > > +}; > > > > Renaming all those enums to lower case creates unneeded churn. > > I undid that in my branch, so now the mount api porting patch is a > > lot smaller. > > Every single filesystem apart from fuse and overlayfs uses the standard > "Opt_" syntax. Only fuse and overlayfs use OPT_* all uppercase. Even the > documenation uses Opt_* throughout. > > So I'd appreciate it if you please did not go out of your way to deviate > from this. I already did the work to convert to the Opt_* format on > purpose. If you want less churn however, then you can ofc move this to a > preparatory patch that converts to the standard format. okay. as long as the logical changes are separate from the renaming. Thanks, Amir.
On Fri, Jun 16, 2023 at 4:37 PM Amir Goldstein <amir73il@gmail.com> wrote: > > On Fri, Jun 16, 2023 at 4:28 PM Christian Brauner <brauner@kernel.org> wrote: > > > > On Fri, Jun 16, 2023 at 04:21:29PM +0300, Amir Goldstein wrote: > > > On Tue, Jun 13, 2023 at 5:49 PM Christian Brauner <brauner@kernel.org> wrote: > > > > > > > > We recently ported util-linux to the new mount api. Now the mount(8) > > > > tool will by default use the new mount api. While trying hard to fall > > > > back to the old mount api gracefully there are still cases where we run > > > > into issues that are difficult to handle nicely. > > > > > > > > Now with mount(8) and libmount supporting the new mount api I expect an > > > > increase in the number of bug reports and issues we're going to see with > > > > filesystems that don't yet support the new mount api. So it's time we > > > > rectify this. > > > > > > > > Signed-off-by: Christian Brauner <brauner@kernel.org> > > > > --- > > > > fs/overlayfs/ovl_entry.h | 2 +- > > > > fs/overlayfs/super.c | 557 ++++++++++++++++++++++++++--------------------- > > > > 2 files changed, 305 insertions(+), 254 deletions(-) > > > > > > > > diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h > > > > index e5207c4bf5b8..c72433c06006 100644 > > > > --- a/fs/overlayfs/ovl_entry.h > > > > +++ b/fs/overlayfs/ovl_entry.h > > > > @@ -12,7 +12,7 @@ struct ovl_config { > > > > bool default_permissions; > > > > bool redirect_dir; > > > > bool redirect_follow; > > > > - const char *redirect_mode; > > > > + unsigned redirect_mode; > > > > > > I have a separate patch to get rid of redirect_dir and redirect_follow > > > leaving only redirect_mode enum. > > > > > > I've already rebased your patches over this change in my branch. > > > > > > https://github.com/amir73il/linux/commits/fs-overlayfs-mount_api > > > > > > > > > > bool index; > > > > bool uuid; > > > > bool nfs_export; > > > > diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c > > > > index d9be5d318e1b..3392dc5d2082 100644 > > > > --- a/fs/overlayfs/super.c > > > > +++ b/fs/overlayfs/super.c > > > > @@ -16,6 +16,8 @@ > > > > #include <linux/posix_acl_xattr.h> > > > > #include <linux/exportfs.h> > > > > #include <linux/file.h> > > > > +#include <linux/fs_context.h> > > > > +#include <linux/fs_parser.h> > > > > #include "overlayfs.h" > > > > > > > > MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); > > > > @@ -59,6 +61,79 @@ module_param_named(metacopy, ovl_metacopy_def, bool, 0644); > > > > MODULE_PARM_DESC(metacopy, > > > > "Default to on or off for the metadata only copy up feature"); > > > > > > > > +enum { > > > > + Opt_lowerdir, > > > > + Opt_upperdir, > > > > + Opt_workdir, > > > > + Opt_default_permissions, > > > > + Opt_redirect_dir, > > > > + Opt_index, > > > > + Opt_uuid, > > > > + Opt_nfs_export, > > > > + Opt_userxattr, > > > > + Opt_xino, > > > > + Opt_metacopy, > > > > + Opt_volatile, > > > > +}; > > > > > > Renaming all those enums to lower case creates unneeded churn. > > > I undid that in my branch, so now the mount api porting patch is a > > > lot smaller. > > > > Every single filesystem apart from fuse and overlayfs uses the standard > > "Opt_" syntax. Only fuse and overlayfs use OPT_* all uppercase. Even the > > documenation uses Opt_* throughout. > > > > So I'd appreciate it if you please did not go out of your way to deviate > > from this. I already did the work to convert to the Opt_* format on > > purpose. If you want less churn however, then you can ofc move this to a > > preparatory patch that converts to the standard format. > > okay. > as long as the logical changes are separate from the renaming. Looking at it again, after my prep patches, this enum rename does not make reviewing harder, so I restored the Opt_* names and pushed to my branch. Thanks, Amir.
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index e5207c4bf5b8..c72433c06006 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -12,7 +12,7 @@ struct ovl_config { bool default_permissions; bool redirect_dir; bool redirect_follow; - const char *redirect_mode; + unsigned redirect_mode; bool index; bool uuid; bool nfs_export; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index d9be5d318e1b..3392dc5d2082 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -16,6 +16,8 @@ #include <linux/posix_acl_xattr.h> #include <linux/exportfs.h> #include <linux/file.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> #include "overlayfs.h" MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); @@ -59,6 +61,79 @@ module_param_named(metacopy, ovl_metacopy_def, bool, 0644); MODULE_PARM_DESC(metacopy, "Default to on or off for the metadata only copy up feature"); +enum { + Opt_lowerdir, + Opt_upperdir, + Opt_workdir, + Opt_default_permissions, + Opt_redirect_dir, + Opt_index, + Opt_uuid, + Opt_nfs_export, + Opt_userxattr, + Opt_xino, + Opt_metacopy, + Opt_volatile, +}; + +static const struct constant_table ovl_parameter_bool[] = { + { "on", true }, + { "off", false }, + {} +}; + +static const struct constant_table ovl_parameter_xino[] = { + { "on", OVL_XINO_ON }, + { "off", OVL_XINO_OFF }, + { "auto", OVL_XINO_AUTO }, + {} +}; + +enum { + OVL_REDIRECT_DIR_ON, + OVL_REDIRECT_DIR_OFF, + OVL_REDIRECT_DIR_FOLLOW, + OVL_REDIRECT_DIR_NOFOLLOW, +}; + +static const struct constant_table ovl_parameter_redirect_dir[] = { + { "on", OVL_REDIRECT_DIR_ON }, + { "off", OVL_REDIRECT_DIR_OFF }, + { "follow", OVL_REDIRECT_DIR_FOLLOW }, + { "nofollow", OVL_REDIRECT_DIR_NOFOLLOW }, + {} +}; + +static const char *ovl_redirect_mode(struct ovl_config *config) +{ + return ovl_parameter_redirect_dir[config->redirect_mode].name; +} + +static const struct fs_parameter_spec ovl_parameter_spec[] = { + fsparam_string("lowerdir", Opt_lowerdir), + fsparam_string("upperdir", Opt_upperdir), + fsparam_string("workdir", Opt_workdir), + fsparam_flag("default_permissions", Opt_default_permissions), + fsparam_enum("redirect_dir", Opt_redirect_dir, ovl_parameter_redirect_dir), + fsparam_enum("index", Opt_index, ovl_parameter_bool), + fsparam_enum("uuid", Opt_uuid, ovl_parameter_bool), + fsparam_enum("nfs_export", Opt_nfs_export, ovl_parameter_bool), + fsparam_flag("userxattr", Opt_userxattr), + fsparam_enum("xino", Opt_xino, ovl_parameter_xino), + fsparam_enum("metacopy", Opt_metacopy, ovl_parameter_bool), + fsparam_flag("volatile", Opt_volatile), + {} +}; + +#define OVL_METACOPY_SET BIT(0) +#define OVL_REDIRECT_SET BIT(1) +#define OVL_NFS_EXPORT_SET BIT(2) +#define OVL_INDEX_SET BIT(3) + +struct ovl_fs_context { + u8 set; +}; + static struct dentry *ovl_d_real(struct dentry *dentry, const struct inode *inode) { @@ -243,7 +318,6 @@ static void ovl_free_fs(struct ovl_fs *ofs) kfree(ofs->config.lowerdir); kfree(ofs->config.upperdir); kfree(ofs->config.workdir); - kfree(ofs->config.redirect_mode); if (ofs->creator_cred) put_cred(ofs->creator_cred); kfree(ofs); @@ -253,7 +327,8 @@ static void ovl_put_super(struct super_block *sb) { struct ovl_fs *ofs = sb->s_fs_info; - ovl_free_fs(ofs); + if (ofs) + ovl_free_fs(ofs); } /* Sync real dirty inodes in upper filesystem (if it exists) */ @@ -357,6 +432,7 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) { struct super_block *sb = dentry->d_sb; struct ovl_fs *ofs = sb->s_fs_info; + const char *redirect_mode; seq_show_option(m, "lowerdir", ofs->config.lowerdir); if (ofs->config.upperdir) { @@ -365,8 +441,9 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) } if (ofs->config.default_permissions) seq_puts(m, ",default_permissions"); - if (strcmp(ofs->config.redirect_mode, ovl_redirect_mode_def()) != 0) - seq_printf(m, ",redirect_dir=%s", ofs->config.redirect_mode); + redirect_mode = ovl_redirect_mode(&ofs->config); + if (strcmp(redirect_mode, ovl_redirect_mode_def()) != 0) + seq_printf(m, ",redirect_dir=%s", redirect_mode); if (ofs->config.index != ovl_index_def) seq_printf(m, ",index=%s", ofs->config.index ? "on" : "off"); if (!ofs->config.uuid) @@ -386,27 +463,6 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) return 0; } -static int ovl_remount(struct super_block *sb, int *flags, char *data) -{ - struct ovl_fs *ofs = sb->s_fs_info; - struct super_block *upper_sb; - int ret = 0; - - if (!(*flags & SB_RDONLY) && ovl_force_readonly(ofs)) - return -EROFS; - - if (*flags & SB_RDONLY && !sb_rdonly(sb)) { - upper_sb = ovl_upper_mnt(ofs)->mnt_sb; - if (ovl_should_sync(ofs)) { - down_read(&upper_sb->s_umount); - ret = sync_filesystem(upper_sb); - up_read(&upper_sb->s_umount); - } - } - - return ret; -} - static const struct super_operations ovl_super_operations = { .alloc_inode = ovl_alloc_inode, .free_inode = ovl_free_inode, @@ -416,216 +472,42 @@ static const struct super_operations ovl_super_operations = { .sync_fs = ovl_sync_fs, .statfs = ovl_statfs, .show_options = ovl_show_options, - .remount_fs = ovl_remount, -}; - -enum { - OPT_LOWERDIR, - OPT_UPPERDIR, - OPT_WORKDIR, - OPT_DEFAULT_PERMISSIONS, - OPT_REDIRECT_DIR, - OPT_INDEX_ON, - OPT_INDEX_OFF, - OPT_UUID_ON, - OPT_UUID_OFF, - OPT_NFS_EXPORT_ON, - OPT_USERXATTR, - OPT_NFS_EXPORT_OFF, - OPT_XINO_ON, - OPT_XINO_OFF, - OPT_XINO_AUTO, - OPT_METACOPY_ON, - OPT_METACOPY_OFF, - OPT_VOLATILE, - OPT_ERR, -}; - -static const match_table_t ovl_tokens = { - {OPT_LOWERDIR, "lowerdir=%s"}, - {OPT_UPPERDIR, "upperdir=%s"}, - {OPT_WORKDIR, "workdir=%s"}, - {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, - {OPT_REDIRECT_DIR, "redirect_dir=%s"}, - {OPT_INDEX_ON, "index=on"}, - {OPT_INDEX_OFF, "index=off"}, - {OPT_USERXATTR, "userxattr"}, - {OPT_UUID_ON, "uuid=on"}, - {OPT_UUID_OFF, "uuid=off"}, - {OPT_NFS_EXPORT_ON, "nfs_export=on"}, - {OPT_NFS_EXPORT_OFF, "nfs_export=off"}, - {OPT_XINO_ON, "xino=on"}, - {OPT_XINO_OFF, "xino=off"}, - {OPT_XINO_AUTO, "xino=auto"}, - {OPT_METACOPY_ON, "metacopy=on"}, - {OPT_METACOPY_OFF, "metacopy=off"}, - {OPT_VOLATILE, "volatile"}, - {OPT_ERR, NULL} }; -static char *ovl_next_opt(char **s) +static int ovl_set_redirect_mode(struct ovl_config *config) { - char *sbegin = *s; - char *p; - - if (sbegin == NULL) - return NULL; - - for (p = sbegin; *p; p++) { - if (*p == '\\') { - p++; - if (!*p) - break; - } else if (*p == ',') { - *p = '\0'; - *s = p + 1; - return sbegin; - } - } - *s = NULL; - return sbegin; -} - -static int ovl_parse_redirect_mode(struct ovl_config *config, const char *mode) -{ - if (strcmp(mode, "on") == 0) { + switch (config->redirect_mode) { + case OVL_REDIRECT_DIR_ON: config->redirect_dir = true; /* * Does not make sense to have redirect creation without * redirect following. */ config->redirect_follow = true; - } else if (strcmp(mode, "follow") == 0) { + return 0; + case OVL_REDIRECT_DIR_FOLLOW: config->redirect_follow = true; - } else if (strcmp(mode, "off") == 0) { + return 0; + case OVL_REDIRECT_DIR_OFF: if (ovl_redirect_always_follow) config->redirect_follow = true; - } else if (strcmp(mode, "nofollow") != 0) { - pr_err("bad mount option \"redirect_dir=%s\"\n", - mode); - return -EINVAL; + return 0; + case OVL_REDIRECT_DIR_NOFOLLOW: + return 0; } - return 0; + pr_err("invalid \"redirect_dir\" mount option\n"); + return -EINVAL; } -static int ovl_parse_opt(char *opt, struct ovl_config *config) +static int ovl_fs_params_verify(const struct ovl_fs_context *ctx, + struct ovl_config *config) { - char *p; int err; - bool metacopy_opt = false, redirect_opt = false; - bool nfs_export_opt = false, index_opt = false; - - config->redirect_mode = kstrdup(ovl_redirect_mode_def(), GFP_KERNEL); - if (!config->redirect_mode) - return -ENOMEM; - - while ((p = ovl_next_opt(&opt)) != NULL) { - int token; - substring_t args[MAX_OPT_ARGS]; - - if (!*p) - continue; - - token = match_token(p, ovl_tokens, args); - switch (token) { - case OPT_UPPERDIR: - kfree(config->upperdir); - config->upperdir = match_strdup(&args[0]); - if (!config->upperdir) - return -ENOMEM; - break; - - case OPT_LOWERDIR: - kfree(config->lowerdir); - config->lowerdir = match_strdup(&args[0]); - if (!config->lowerdir) - return -ENOMEM; - break; - - case OPT_WORKDIR: - kfree(config->workdir); - config->workdir = match_strdup(&args[0]); - if (!config->workdir) - return -ENOMEM; - break; - - case OPT_DEFAULT_PERMISSIONS: - config->default_permissions = true; - break; - - case OPT_REDIRECT_DIR: - kfree(config->redirect_mode); - config->redirect_mode = match_strdup(&args[0]); - if (!config->redirect_mode) - return -ENOMEM; - redirect_opt = true; - break; - - case OPT_INDEX_ON: - config->index = true; - index_opt = true; - break; - - case OPT_INDEX_OFF: - config->index = false; - index_opt = true; - break; - - case OPT_UUID_ON: - config->uuid = true; - break; - - case OPT_UUID_OFF: - config->uuid = false; - break; - - case OPT_NFS_EXPORT_ON: - config->nfs_export = true; - nfs_export_opt = true; - break; - - case OPT_NFS_EXPORT_OFF: - config->nfs_export = false; - nfs_export_opt = true; - break; - - case OPT_XINO_ON: - config->xino = OVL_XINO_ON; - break; - - case OPT_XINO_OFF: - config->xino = OVL_XINO_OFF; - break; - - case OPT_XINO_AUTO: - config->xino = OVL_XINO_AUTO; - break; - - case OPT_METACOPY_ON: - config->metacopy = true; - metacopy_opt = true; - break; - - case OPT_METACOPY_OFF: - config->metacopy = false; - metacopy_opt = true; - break; - - case OPT_VOLATILE: - config->ovl_volatile = true; - break; - - case OPT_USERXATTR: - config->userxattr = true; - break; - - default: - pr_err("unrecognized mount option \"%s\" or missing value\n", - p); - return -EINVAL; - } - } + bool metacopy_opt = ctx->set & OVL_METACOPY_SET; + bool redirect_opt = ctx->set & OVL_REDIRECT_SET; + bool nfs_export_opt = ctx->set & OVL_NFS_EXPORT_SET; + bool index_opt = ctx->set & OVL_INDEX_SET; /* Workdir/index are useless in non-upper mount */ if (!config->upperdir) { @@ -647,7 +529,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) config->ovl_volatile = false; } - err = ovl_parse_redirect_mode(config, config->redirect_mode); + err = ovl_set_redirect_mode(config); if (err) return err; @@ -662,7 +544,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) if (config->metacopy && !config->redirect_dir) { if (metacopy_opt && redirect_opt) { pr_err("conflicting options: metacopy=on,redirect_dir=%s\n", - config->redirect_mode); + ovl_redirect_mode(config)); return -EINVAL; } if (redirect_opt) { @@ -671,7 +553,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) * in this conflict. */ pr_info("disabling metacopy due to redirect_dir=%s\n", - config->redirect_mode); + ovl_redirect_mode(config)); config->metacopy = false; } else { /* Automatically enable redirect otherwise. */ @@ -728,7 +610,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) if (config->userxattr) { if (config->redirect_follow && redirect_opt) { pr_err("conflicting options: userxattr,redirect_dir=%s\n", - config->redirect_mode); + ovl_redirect_mode(config)); return -EINVAL; } if (config->metacopy && metacopy_opt) { @@ -1926,12 +1808,128 @@ static struct dentry *ovl_get_root(struct super_block *sb, return root; } -static int ovl_fill_super(struct super_block *sb, void *data, int silent) +static int ovl_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + int err = 0; + struct fs_parse_result result; + struct ovl_fs *ofs = fc->s_fs_info; + struct ovl_config *config = &ofs->config; + struct ovl_fs_context *ctx = fc->fs_private; + char *dup; + int opt; + + /* + * On remount overlayfs has always ignored all mount options no + * matter if malformed or not so for backwards compatibility we + * do the same here. + */ + if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) + return 0; + + opt = fs_parse(fc, ovl_parameter_spec, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_lowerdir: + dup = kstrdup(param->string, GFP_KERNEL); + if (!dup) { + err = -ENOMEM; + break; + } + + kfree(config->lowerdir); + config->lowerdir = dup; + break; + case Opt_upperdir: + dup = kstrdup(param->string, GFP_KERNEL); + if (!dup) { + err = -ENOMEM; + break; + } + + kfree(config->upperdir); + config->upperdir = dup; + break; + case Opt_workdir: + dup = kstrdup(param->string, GFP_KERNEL); + if (!dup) { + err = -ENOMEM; + break; + } + + kfree(config->workdir); + config->workdir = dup; + break; + case Opt_default_permissions: + config->default_permissions = true; + break; + case Opt_index: + config->index = result.uint_32; + ctx->set |= OVL_INDEX_SET; + break; + case Opt_uuid: + config->uuid = result.uint_32; + break; + case Opt_nfs_export: + config->nfs_export = result.uint_32; + ctx->set |= OVL_NFS_EXPORT_SET; + break; + case Opt_metacopy: + config->metacopy = result.uint_32; + ctx->set |= OVL_METACOPY_SET; + break; + case Opt_userxattr: + config->userxattr = true; + break; + case Opt_volatile: + config->ovl_volatile = true; + break; + case Opt_xino: + config->xino = result.uint_32; + break; + case Opt_redirect_dir: + config->redirect_mode = result.uint_32; + ctx->set |= OVL_REDIRECT_SET; + break; + default: + pr_err("unrecognized mount option \"%s\" or missing value\n", param->key); + return -EINVAL; + } + + return err; +} + + +static int ovl_reconfigure(struct fs_context *fc) { - struct path upperpath = { }; + struct super_block *sb = fc->root->d_sb; + struct ovl_fs *ofs = sb->s_fs_info; + struct super_block *upper_sb; + int ret = 0; + + if (!(fc->sb_flags & SB_RDONLY) && ovl_force_readonly(ofs)) + return -EROFS; + + if (fc->sb_flags & SB_RDONLY && !sb_rdonly(sb)) { + upper_sb = ovl_upper_mnt(ofs)->mnt_sb; + if (ovl_should_sync(ofs)) { + down_read(&upper_sb->s_umount); + ret = sync_filesystem(upper_sb); + up_read(&upper_sb->s_umount); + } + } + + return ret; +} + +static int ovl_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct ovl_fs *ofs = sb->s_fs_info; + struct ovl_fs_context *ctx = fc->fs_private; + struct path upperpath = {}; struct dentry *root_dentry; struct ovl_entry *oe; - struct ovl_fs *ofs; struct ovl_layer *layers; struct cred *cred; char *splitlower = NULL; @@ -1939,36 +1937,24 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) int err; err = -EIO; - if (WARN_ON(sb->s_user_ns != current_user_ns())) - goto out; + if (WARN_ON(fc->user_ns != current_user_ns())) + goto out_err; + ofs->share_whiteout = true; sb->s_d_op = &ovl_dentry_operations; - err = -ENOMEM; - ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); - if (!ofs) - goto out; - err = -ENOMEM; ofs->creator_cred = cred = prepare_creds(); if (!cred) goto out_err; - /* Is there a reason anyone would want not to share whiteouts? */ - ofs->share_whiteout = true; - - ofs->config.index = ovl_index_def; - ofs->config.uuid = true; - ofs->config.nfs_export = ovl_nfs_export_def; - ofs->config.xino = ovl_xino_def(); - ofs->config.metacopy = ovl_metacopy_def; - err = ovl_parse_opt((char *) data, &ofs->config); + err = ovl_fs_params_verify(ctx, &ofs->config); if (err) goto out_err; err = -EINVAL; if (!ofs->config.lowerdir) { - if (!silent) + if (fc->sb_flags & SB_SILENT) pr_err("missing 'lowerdir'\n"); goto out_err; } @@ -2113,25 +2099,90 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) out_free_oe: ovl_free_entry(oe); out_err: - kfree(splitlower); - path_put(&upperpath); - ovl_free_fs(ofs); -out: return err; } -static struct dentry *ovl_mount(struct file_system_type *fs_type, int flags, - const char *dev_name, void *raw_data) +static int ovl_get_tree(struct fs_context *fc) +{ + return get_tree_nodev(fc, ovl_fill_super); +} + +static inline void ovl_fs_context_free(struct ovl_fs_context *ctx) +{ + kfree(ctx); +} + +static void ovl_free(struct fs_context *fc) { - return mount_nodev(fs_type, flags, raw_data, ovl_fill_super); + struct ovl_fs *ofs = fc->s_fs_info; + struct ovl_fs_context *ctx = fc->fs_private; + + /* + * ofs is stored in the fs_context when it is initialized. + * ofs is transferred to the superblock on a successful mount, + * but if an error occurs before the transfer we have to free + * it here. + */ + if (ofs) + ovl_free_fs(ofs); + + if (ctx) + ovl_fs_context_free(ctx); +} + +static const struct fs_context_operations ovl_context_ops = { + .parse_param = ovl_parse_param, + .get_tree = ovl_get_tree, + .reconfigure = ovl_reconfigure, + .free = ovl_free, +}; + +/* + * This is called during fsopen() and will record the user namespace of + * the caller in fc->user_ns since we've raised FS_USERNS_MOUNT. We'll + * need it when we actually create the superblock to verify that the + * process creating the superblock is in the same user namespace as + * process that called fsopen(). + */ +static int ovl_init_fs_context(struct fs_context *fc) +{ + struct ovl_fs_context *ctx; + struct ovl_fs *ofs; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT); + if (!ctx) + return -ENOMEM; + + ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); + if (!ofs) { + ovl_fs_context_free(ctx); + return -ENOMEM; + } + + if (strcmp(ovl_redirect_mode_def(), "on") == 0) + ofs->config.redirect_mode = OVL_REDIRECT_DIR_ON; + else + ofs->config.redirect_mode = OVL_REDIRECT_DIR_OFF; + + ofs->config.index = ovl_index_def; + ofs->config.uuid = true; + ofs->config.nfs_export = ovl_nfs_export_def; + ofs->config.xino = ovl_xino_def(); + ofs->config.metacopy = ovl_metacopy_def; + + fc->s_fs_info = ofs; + fc->fs_private = ctx; + fc->ops = &ovl_context_ops; + return 0; } static struct file_system_type ovl_fs_type = { - .owner = THIS_MODULE, - .name = "overlay", - .fs_flags = FS_USERNS_MOUNT, - .mount = ovl_mount, - .kill_sb = kill_anon_super, + .owner = THIS_MODULE, + .name = "overlay", + .init_fs_context = ovl_init_fs_context, + .parameters = ovl_parameter_spec, + .fs_flags = FS_USERNS_MOUNT, + .kill_sb = kill_anon_super, }; MODULE_ALIAS_FS("overlay");
We recently ported util-linux to the new mount api. Now the mount(8) tool will by default use the new mount api. While trying hard to fall back to the old mount api gracefully there are still cases where we run into issues that are difficult to handle nicely. Now with mount(8) and libmount supporting the new mount api I expect an increase in the number of bug reports and issues we're going to see with filesystems that don't yet support the new mount api. So it's time we rectify this. Signed-off-by: Christian Brauner <brauner@kernel.org> --- fs/overlayfs/ovl_entry.h | 2 +- fs/overlayfs/super.c | 557 ++++++++++++++++++++++++++--------------------- 2 files changed, 305 insertions(+), 254 deletions(-)