--- fs/fuse/inode.c | 272 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 147 insertions(+), 125 deletions(-) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index ec5d9953dfb6..3aebff5b902a 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -15,7 +15,8 @@ #include <linux/init.h> #include <linux/module.h> #include <linux/moduleparam.h> -#include <linux/parser.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> #include <linux/statfs.h> #include <linux/random.h> #include <linux/sched.h> @@ -59,7 +60,12 @@ MODULE_PARM_DESC(max_user_congthresh, /** Congestion starts at 75% of maximum */ #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4) -struct fuse_mount_data { +#ifdef CONFIG_BLOCK +static struct file_system_type fuseblk_fs_type; +#endif + +struct fuse_fs_context { + bool is_bdev; int fd; unsigned rootmode; kuid_t user_id; @@ -448,6 +454,7 @@ static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) } enum { + OPT_SOURCE, OPT_FD, OPT_ROOTMODE, OPT_USER_ID, @@ -459,111 +466,97 @@ enum { OPT_ERR }; -static const match_table_t tokens = { - {OPT_FD, "fd=%u"}, - {OPT_ROOTMODE, "rootmode=%o"}, - {OPT_USER_ID, "user_id=%u"}, - {OPT_GROUP_ID, "group_id=%u"}, - {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, - {OPT_ALLOW_OTHER, "allow_other"}, - {OPT_MAX_READ, "max_read=%u"}, - {OPT_BLKSIZE, "blksize=%u"}, - {OPT_ERR, NULL} +static const struct fs_parameter_spec fuse_param_specs[] = { + fsparam_string ("source", OPT_SOURCE), + fsparam_fd ("fd", OPT_FD), + fsparam_u32oct ("rootmode", OPT_ROOTMODE), + fsparam_u32 ("user_id", OPT_USER_ID), + fsparam_u32 ("group_id", OPT_GROUP_ID), + fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS), + fsparam_flag ("allow_other", OPT_ALLOW_OTHER), + fsparam_u32 ("max_read", OPT_MAX_READ), + fsparam_u32 ("blksize", OPT_BLKSIZE), + {} }; -static int fuse_match_uint(substring_t *s, unsigned int *res) +static const struct fs_parameter_description fuse_fs_parameters = { + .name = "fuse", + .specs = fuse_param_specs, +}; + +static int fuse_parse_param(struct fs_context *fc, struct fs_parameter *param) { - int err = -ENOMEM; - char *buf = match_strdup(s); - if (buf) { - err = kstrtouint(buf, 10, res); - kfree(buf); + struct fs_parse_result result; + struct fuse_fs_context *ctx = fc->fs_private; + int opt; + + opt = fs_parse(fc, &fuse_fs_parameters, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case OPT_SOURCE: + kfree(fc->source); + fc->source = param->string; + param->string = NULL; + break; + + case OPT_FD: + ctx->fd = result.uint_32; + ctx->fd_present = 1; + break; + + case OPT_ROOTMODE: + if (!fuse_valid_type(result.uint_32)) + return invalf(fc, "fuse: Invalid rootmode"); + ctx->rootmode = result.uint_32; + ctx->rootmode_present = 1; + break; + + case OPT_USER_ID: + ctx->user_id = make_kuid(fc->user_ns, result.uint_32); + if (!uid_valid(ctx->user_id)) + return invalf(fc, "fuse: Invalid user_id"); + ctx->user_id_present = 1; + break; + + case OPT_GROUP_ID: + ctx->group_id = make_kgid(fc->user_ns, result.uint_32); + if (!gid_valid(ctx->group_id)) + return invalf(fc, "fuse: Invalid group_id"); + ctx->group_id_present = 1; + break; + + case OPT_DEFAULT_PERMISSIONS: + ctx->default_permissions = 1; + break; + + case OPT_ALLOW_OTHER: + ctx->allow_other = 1; + break; + + case OPT_MAX_READ: + ctx->max_read = result.uint_32; + break; + + case OPT_BLKSIZE: + if (!ctx->is_bdev) + return invalf(fc, "fuse: blksize only supported for fuseblk"); + ctx->blksize = result.uint_32; + break; + + default: + return -EINVAL; } - return err; + + return 0; } -static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev, - struct user_namespace *user_ns) +static void fuse_free_fc(struct fs_context *fc) { - char *p; - memset(d, 0, sizeof(struct fuse_mount_data)); - d->max_read = ~0; - d->blksize = FUSE_DEFAULT_BLKSIZE; - - while ((p = strsep(&opt, ",")) != NULL) { - int token; - int value; - unsigned uv; - substring_t args[MAX_OPT_ARGS]; - if (!*p) - continue; - - token = match_token(p, tokens, args); - switch (token) { - case OPT_FD: - if (match_int(&args[0], &value)) - return 0; - d->fd = value; - d->fd_present = 1; - break; - - case OPT_ROOTMODE: - if (match_octal(&args[0], &value)) - return 0; - if (!fuse_valid_type(value)) - return 0; - d->rootmode = value; - d->rootmode_present = 1; - break; - - case OPT_USER_ID: - if (fuse_match_uint(&args[0], &uv)) - return 0; - d->user_id = make_kuid(user_ns, uv); - if (!uid_valid(d->user_id)) - return 0; - d->user_id_present = 1; - break; - - case OPT_GROUP_ID: - if (fuse_match_uint(&args[0], &uv)) - return 0; - d->group_id = make_kgid(user_ns, uv); - if (!gid_valid(d->group_id)) - return 0; - d->group_id_present = 1; - break; - - case OPT_DEFAULT_PERMISSIONS: - d->default_permissions = 1; - break; - - case OPT_ALLOW_OTHER: - d->allow_other = 1; - break; - - case OPT_MAX_READ: - if (match_int(&args[0], &value)) - return 0; - d->max_read = value; - break; - - case OPT_BLKSIZE: - if (!is_bdev || match_int(&args[0], &value)) - return 0; - d->blksize = value; - break; - - default: - return 0; - } - } - - if (!d->fd_present || !d->rootmode_present || - !d->user_id_present || !d->group_id_present) - return 0; + struct fuse_fs_context *ctx = fc->fs_private; - return 1; + kfree(ctx); } static int fuse_show_options(struct seq_file *m, struct dentry *root) @@ -1078,12 +1071,12 @@ void fuse_dev_free(struct fuse_dev *fud) } EXPORT_SYMBOL_GPL(fuse_dev_free); -static int fuse_fill_super(struct super_block *sb, void *data, int silent) +static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc) { + struct fuse_fs_context *ctx = fsc->fs_private; struct fuse_dev *fud; struct fuse_conn *fc; struct inode *root; - struct fuse_mount_data d; struct file *file; struct dentry *root_dentry; struct fuse_req *init_req; @@ -1096,13 +1089,10 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); - if (!parse_fuse_opt(data, &d, is_bdev, sb->s_user_ns)) - goto err; - if (is_bdev) { #ifdef CONFIG_BLOCK err = -EINVAL; - if (!sb_set_blocksize(sb, d.blksize)) + if (!sb_set_blocksize(sb, ctx->blksize)) goto err; #endif } else { @@ -1119,7 +1109,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) if (sb->s_user_ns != &init_user_ns) sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; - file = fget(d.fd); + file = fget(ctx->fd); err = -EINVAL; if (!file) goto err; @@ -1162,17 +1152,17 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) fc->dont_mask = 1; sb->s_flags |= SB_POSIXACL; - fc->default_permissions = d.default_permissions; - fc->allow_other = d.allow_other; - fc->user_id = d.user_id; - fc->group_id = d.group_id; - fc->max_read = max_t(unsigned, 4096, d.max_read); + fc->default_permissions = ctx->default_permissions; + fc->allow_other = ctx->allow_other; + fc->user_id = ctx->user_id; + fc->group_id = ctx->group_id; + fc->max_read = max_t(unsigned, 4096, ctx->max_read); /* Used by get_root_inode() */ sb->s_fs_info = fc; err = -ENOMEM; - root = fuse_get_root_inode(sb, d.rootmode); + root = fuse_get_root_inode(sb, ctx->rootmode); sb->s_d_op = &fuse_root_dentry_operations; root_dentry = d_make_root(root); if (!root_dentry) @@ -1232,11 +1222,48 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) return err; } -static struct dentry *fuse_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, - void *raw_data) +static int fuse_get_tree(struct fs_context *fc) +{ + struct fuse_fs_context *ctx = fc->fs_private; + + if (!ctx->fd_present || !ctx->rootmode_present || + !ctx->user_id_present || !ctx->group_id_present) + return invalf(fc, "fuse: Missing mount parameter(s)"); + + if (ctx->is_bdev) + return vfs_get_block_super(fc, fuse_fill_super); + + return vfs_get_super(fc, vfs_get_independent_super, fuse_fill_super); +} + +static const struct fs_context_operations fuse_context_ops = { + .free = fuse_free_fc, + .parse_param = fuse_parse_param, + .get_tree = fuse_get_tree, +}; + +/* + * Set up the filesystem mount context. + */ +static int fuse_init_fs_context(struct fs_context *fc) { - return mount_nodev(fs_type, flags, raw_data, fuse_fill_super); + struct fuse_fs_context *ctx; + + ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->max_read = ~0; + ctx->blksize = FUSE_DEFAULT_BLKSIZE; + +#ifdef CONFIG_BLOCK + if (fc->fs_type == &fuseblk_fs_type) + ctx->is_bdev = true; +#endif + + fc->fs_private = ctx; + fc->ops = &fuse_context_ops; + return 0; } static void fuse_sb_destroy(struct super_block *sb) @@ -1265,19 +1292,13 @@ static struct file_system_type fuse_fs_type = { .owner = THIS_MODULE, .name = "fuse", .fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT, - .mount = fuse_mount, + .init_fs_context = fuse_init_fs_context, + .parameters = &fuse_fs_parameters, .kill_sb = fuse_kill_sb_anon, }; MODULE_ALIAS_FS("fuse"); #ifdef CONFIG_BLOCK -static struct dentry *fuse_mount_blk(struct file_system_type *fs_type, - int flags, const char *dev_name, - void *raw_data) -{ - return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super); -} - static void fuse_kill_sb_blk(struct super_block *sb) { fuse_sb_destroy(sb); @@ -1287,7 +1308,8 @@ static void fuse_kill_sb_blk(struct super_block *sb) static struct file_system_type fuseblk_fs_type = { .owner = THIS_MODULE, .name = "fuseblk", - .mount = fuse_mount_blk, + .init_fs_context = fuse_init_fs_context, + .parameters = &fuse_fs_parameters, .kill_sb = fuse_kill_sb_blk, .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, };