ext4: Change handle_mount_opt() to use fs_parameter
authorLukas Czerner <lczerner@redhat.com>
Wed, 27 Oct 2021 14:18:48 +0000 (16:18 +0200)
committerTheodore Ts'o <tytso@mit.edu>
Thu, 9 Dec 2021 19:11:07 +0000 (14:11 -0500)
Use the new mount option specifications to parse the options in
handle_mount_opt(). However we're still using the old API to get the
options string.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Link: https://lore.kernel.org/r/20211027141857.33657-5-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
fs/ext4/super.c

index e62187b..3d8caf0 100644 (file)
@@ -1981,7 +1981,8 @@ static const char deprecated_msg[] =
        "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
 
 #ifdef CONFIG_QUOTA
-static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
+static int set_qf_name(struct super_block *sb, int qtype,
+                      struct fs_parameter *param)
 {
        struct ext4_sb_info *sbi = EXT4_SB(sb);
        char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
@@ -1998,7 +1999,7 @@ static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
                         "ignored when QUOTA feature is enabled");
                return 1;
        }
-       qname = match_strdup(args);
+       qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
        if (!qname) {
                ext4_msg(sb, KERN_ERR,
                        "Not enough memory for storing quotafile name");
@@ -2204,8 +2205,7 @@ static int ext4_sb_read_encoding(const struct ext4_super_block *es,
 #endif
 
 static int ext4_set_test_dummy_encryption(struct super_block *sb,
-                                         const char *opt,
-                                         const substring_t *arg,
+                                         struct fs_parameter *param,
                                          bool is_remount)
 {
 #ifdef CONFIG_FS_ENCRYPTION
@@ -2223,7 +2223,7 @@ static int ext4_set_test_dummy_encryption(struct super_block *sb,
                         "Can't set test_dummy_encryption on remount");
                return -1;
        }
-       err = fscrypt_set_test_dummy_encryption(sb, arg->from,
+       err = fscrypt_set_test_dummy_encryption(sb, param->string,
                                                &sbi->s_dummy_enc_policy);
        if (err) {
                if (err == -EEXIST)
@@ -2231,11 +2231,12 @@ static int ext4_set_test_dummy_encryption(struct super_block *sb,
                                 "Can't change test_dummy_encryption on remount");
                else if (err == -EINVAL)
                        ext4_msg(sb, KERN_WARNING,
-                                "Value of option \"%s\" is unrecognized", opt);
+                                "Value of option \"%s\" is unrecognized",
+                                param->key);
                else
                        ext4_msg(sb, KERN_WARNING,
                                 "Error processing option \"%s\" [%d]",
-                                opt, err);
+                                param->key, err);
                return -1;
        }
        ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
@@ -2246,41 +2247,52 @@ static int ext4_set_test_dummy_encryption(struct super_block *sb,
        return 1;
 }
 
-struct ext4_parsed_options {
+struct ext4_fs_context {
        unsigned long journal_devnum;
        unsigned int journal_ioprio;
        int mb_optimize_scan;
 };
 
-static int handle_mount_opt(struct super_block *sb, char *opt, int token,
-                           substring_t *args, struct ext4_parsed_options *parsed_opts,
-                           int is_remount)
+static int handle_mount_opt(struct fs_context *fc, struct fs_parameter *param)
 {
-       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       struct ext4_fs_context *ctx = fc->fs_private;
+       struct ext4_sb_info *sbi = fc->s_fs_info;
+       struct super_block *sb = sbi->s_sb;
+       struct fs_parse_result result;
        const struct mount_opts *m;
+       int is_remount;
        kuid_t uid;
        kgid_t gid;
-       int arg = 0;
+       int token;
+
+       token = fs_parse(fc, ext4_param_specs, param, &result);
+       if (token < 0)
+               return token;
+       is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
 
 #ifdef CONFIG_QUOTA
-       if (token == Opt_usrjquota)
-               return set_qf_name(sb, USRQUOTA, &args[0]);
-       else if (token == Opt_grpjquota)
-               return set_qf_name(sb, GRPQUOTA, &args[0]);
-       else if (token == Opt_offusrjquota)
-               return clear_qf_name(sb, USRQUOTA);
-       else if (token == Opt_offgrpjquota)
-               return clear_qf_name(sb, GRPQUOTA);
+       if (token == Opt_usrjquota) {
+               if (!*param->string)
+                       return clear_qf_name(sb, USRQUOTA);
+               else
+                       return set_qf_name(sb, USRQUOTA, param);
+       } else if (token == Opt_grpjquota) {
+               if (!*param->string)
+                       return clear_qf_name(sb, GRPQUOTA);
+               else
+                       return set_qf_name(sb, GRPQUOTA, param);
+       }
 #endif
        switch (token) {
        case Opt_noacl:
        case Opt_nouser_xattr:
-               ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
+               ext4_msg(sb, KERN_WARNING, deprecated_msg, param->key, "3.5");
                break;
        case Opt_sb:
                return 1;       /* handled by get_sb_block() */
        case Opt_removed:
-               ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
+               ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option",
+                        param->key);
                return 1;
        case Opt_abort:
                ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
@@ -2301,6 +2313,12 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
                ext4_msg(sb, KERN_ERR, "inline encryption not supported");
 #endif
                return 1;
+       case Opt_errors:
+       case Opt_data:
+       case Opt_data_err:
+       case Opt_jqfmt:
+       case Opt_dax_type:
+               token = result.uint_32;
        }
 
        for (m = ext4_mount_opts; m->token != Opt_err; m++)
@@ -2309,25 +2327,23 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 
        if (m->token == Opt_err) {
                ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
-                        "or missing value", opt);
+                        "or missing value", param->key);
                return -1;
        }
 
        if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
                ext4_msg(sb, KERN_ERR,
-                        "Mount option \"%s\" incompatible with ext2", opt);
+                        "Mount option \"%s\" incompatible with ext2",
+                        param->key);
                return -1;
        }
        if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
                ext4_msg(sb, KERN_ERR,
-                        "Mount option \"%s\" incompatible with ext3", opt);
+                        "Mount option \"%s\" incompatible with ext3",
+                        param->key);
                return -1;
        }
 
-       if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
-               return -1;
-       if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
-               return -1;
        if (m->flags & MOPT_EXPLICIT) {
                if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
                        set_opt2(sb, EXPLICIT_DELALLOC);
@@ -2345,63 +2361,69 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
        }
 
        if (m->flags & MOPT_NOSUPPORT) {
-               ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
+               ext4_msg(sb, KERN_ERR, "%s option not supported",
+                        param->key);
        } else if (token == Opt_commit) {
-               if (arg == 0)
-                       arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
-               else if (arg > INT_MAX / HZ) {
+               if (result.uint_32 == 0)
+                       sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
+               else if (result.uint_32 > INT_MAX / HZ) {
                        ext4_msg(sb, KERN_ERR,
                                 "Invalid commit interval %d, "
                                 "must be smaller than %d",
-                                arg, INT_MAX / HZ);
+                                result.uint_32, INT_MAX / HZ);
                        return -1;
                }
-               sbi->s_commit_interval = HZ * arg;
+               sbi->s_commit_interval = HZ * result.uint_32;
        } else if (token == Opt_debug_want_extra_isize) {
-               if ((arg & 1) ||
-                   (arg < 4) ||
-                   (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
+               if ((result.uint_32 & 1) ||
+                   (result.uint_32 < 4) ||
+                   (result.uint_32 >
+                    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
                        ext4_msg(sb, KERN_ERR,
-                                "Invalid want_extra_isize %d", arg);
+                                "Invalid want_extra_isize %d", result.uint_32);
                        return -1;
                }
-               sbi->s_want_extra_isize = arg;
+               sbi->s_want_extra_isize = result.uint_32;
        } else if (token == Opt_max_batch_time) {
-               sbi->s_max_batch_time = arg;
+               sbi->s_max_batch_time = result.uint_32;
        } else if (token == Opt_min_batch_time) {
-               sbi->s_min_batch_time = arg;
+               sbi->s_min_batch_time = result.uint_32;
        } else if (token == Opt_inode_readahead_blks) {
-               if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
+               if (result.uint_32 &&
+                   (result.uint_32 > (1 << 30) ||
+                    !is_power_of_2(result.uint_32))) {
                        ext4_msg(sb, KERN_ERR,
                                 "EXT4-fs: inode_readahead_blks must be "
                                 "0 or a power of 2 smaller than 2^31");
                        return -1;
                }
-               sbi->s_inode_readahead_blks = arg;
+               sbi->s_inode_readahead_blks = result.uint_32;
        } else if (token == Opt_init_itable) {
                set_opt(sb, INIT_INODE_TABLE);
-               if (!args->from)
-                       arg = EXT4_DEF_LI_WAIT_MULT;
-               sbi->s_li_wait_mult = arg;
+               sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
+               if (param->type == fs_value_is_string)
+                       sbi->s_li_wait_mult = result.uint_32;
        } else if (token == Opt_max_dir_size_kb) {
-               sbi->s_max_dir_size_kb = arg;
+               sbi->s_max_dir_size_kb = result.uint_32;
 #ifdef CONFIG_EXT4_DEBUG
        } else if (token == Opt_fc_debug_max_replay) {
-               sbi->s_fc_debug_max_replay = arg;
+               sbi->s_fc_debug_max_replay = result.uint_32;
 #endif
        } else if (token == Opt_stripe) {
-               sbi->s_stripe = arg;
+               sbi->s_stripe = result.uint_32;
        } else if (token == Opt_resuid) {
-               uid = make_kuid(current_user_ns(), arg);
+               uid = make_kuid(current_user_ns(), result.uint_32);
                if (!uid_valid(uid)) {
-                       ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
+                       ext4_msg(sb, KERN_ERR, "Invalid uid value %d",
+                                result.uint_32);
                        return -1;
                }
                sbi->s_resuid = uid;
        } else if (token == Opt_resgid) {
-               gid = make_kgid(current_user_ns(), arg);
+               gid = make_kgid(current_user_ns(), result.uint_32);
                if (!gid_valid(gid)) {
-                       ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
+                       ext4_msg(sb, KERN_ERR, "Invalid gid value %d",
+                                result.uint_32);
                        return -1;
                }
                sbi->s_resgid = gid;
@@ -2411,9 +2433,8 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
                                 "Cannot specify journal on remount");
                        return -1;
                }
-               parsed_opts->journal_devnum = arg;
+               ctx->journal_devnum = result.uint_32;
        } else if (token == Opt_journal_path) {
-               char *journal_path;
                struct inode *journal_inode;
                struct path path;
                int error;
@@ -2423,44 +2444,27 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
                                 "Cannot specify journal on remount");
                        return -1;
                }
-               journal_path = match_strdup(&args[0]);
-               if (!journal_path) {
-                       ext4_msg(sb, KERN_ERR, "error: could not dup "
-                               "journal device string");
-                       return -1;
-               }
 
-               error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
+               error = fs_lookup_param(fc, param, 1, &path);
                if (error) {
                        ext4_msg(sb, KERN_ERR, "error: could not find "
-                               "journal device path: error %d", error);
-                       kfree(journal_path);
+                                "journal device path");
                        return -1;
                }
 
                journal_inode = d_inode(path.dentry);
-               if (!S_ISBLK(journal_inode->i_mode)) {
-                       ext4_msg(sb, KERN_ERR, "error: journal path %s "
-                               "is not a block device", journal_path);
-                       path_put(&path);
-                       kfree(journal_path);
-                       return -1;
-               }
-
-               parsed_opts->journal_devnum = new_encode_dev(journal_inode->i_rdev);
+               ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
                path_put(&path);
-               kfree(journal_path);
        } else if (token == Opt_journal_ioprio) {
-               if (arg > 7) {
+               if (result.uint_32 > 7) {
                        ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
                                 " (must be 0-7)");
                        return -1;
                }
-               parsed_opts->journal_ioprio =
-                       IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
+               ctx->journal_ioprio =
+                       IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
        } else if (token == Opt_test_dummy_encryption) {
-               return ext4_set_test_dummy_encryption(sb, opt, &args[0],
-                                                     is_remount);
+               return ext4_set_test_dummy_encryption(sb, param, is_remount);
        } else if (m->flags & MOPT_DATAJ) {
                if (is_remount) {
                        if (!sbi->s_journal)
@@ -2547,30 +2551,35 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
        } else if (token == Opt_data_err_ignore) {
                sbi->s_mount_opt &= ~m->mount_opt;
        } else if (token == Opt_mb_optimize_scan) {
-               if (arg != 0 && arg != 1) {
+               if (result.int_32 != 0 && result.int_32 != 1) {
                        ext4_msg(sb, KERN_WARNING,
                                 "mb_optimize_scan should be set to 0 or 1.");
                        return -1;
                }
-               parsed_opts->mb_optimize_scan = arg;
+               ctx->mb_optimize_scan = result.int_32;
        } else {
-               if (!args->from)
-                       arg = 1;
+               unsigned int set = 0;
+
+               if ((param->type == fs_value_is_flag) ||
+                   result.uint_32 > 0)
+                       set = 1;
+
                if (m->flags & MOPT_CLEAR)
-                       arg = !arg;
+                       set = !set;
                else if (unlikely(!(m->flags & MOPT_SET))) {
                        ext4_msg(sb, KERN_WARNING,
-                                "buggy handling of option %s", opt);
+                                "buggy handling of option %s",
+                                param->key);
                        WARN_ON(1);
                        return -1;
                }
                if (m->flags & MOPT_2) {
-                       if (arg != 0)
+                       if (set != 0)
                                sbi->s_mount_opt2 |= m->mount_opt;
                        else
                                sbi->s_mount_opt2 &= ~m->mount_opt;
                } else {
-                       if (arg != 0)
+                       if (set != 0)
                                sbi->s_mount_opt |= m->mount_opt;
                        else
                                sbi->s_mount_opt &= ~m->mount_opt;
@@ -2580,29 +2589,56 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 }
 
 static int parse_options(char *options, struct super_block *sb,
-                        struct ext4_parsed_options *ret_opts,
+                        struct ext4_fs_context *ret_opts,
                         int is_remount)
 {
-       substring_t args[MAX_OPT_ARGS];
-       int token;
-       char *p;
+       struct fs_parameter param;
+       struct fs_context fc;
+       int ret;
+       char *key;
 
        if (!options)
                return 1;
 
-       while ((p = strsep(&options, ",")) != NULL) {
-               if (!*p)
-                       continue;
-               /*
-                * Initialize args struct so we know whether arg was
-                * found; some options take optional arguments.
-                */
-               args[0].to = args[0].from = NULL;
-               token = match_token(p, tokens, args);
-               if (handle_mount_opt(sb, p, token, args, ret_opts,
-                                    is_remount) < 0)
-                       return 0;
+       memset(&fc, 0, sizeof(fc));
+       fc.fs_private = ret_opts;
+       fc.s_fs_info = EXT4_SB(sb);
+
+       if (is_remount)
+               fc.purpose = FS_CONTEXT_FOR_RECONFIGURE;
+
+       while ((key = strsep(&options, ",")) != NULL) {
+               if (*key) {
+                       size_t v_len = 0;
+                       char *value = strchr(key, '=');
+
+                       param.type = fs_value_is_flag;
+                       param.string = NULL;
+
+                       if (value) {
+                               if (value == key)
+                                       continue;
+
+                               *value++ = 0;
+                               v_len = strlen(value);
+                               param.string = kmemdup_nul(value, v_len,
+                                                          GFP_KERNEL);
+                               if (!param.string)
+                                       return 0;
+                               param.type = fs_value_is_string;
+                       }
+
+                       param.key = key;
+                       param.size = v_len;
+
+                       ret = handle_mount_opt(&fc, &param);
+                       if (param.string)
+                               kfree(param.string);
+                       if (ret < 0)
+                               return 0;
+               }
        }
+
        return ext4_validate_options(sb);
 }
 
@@ -4057,7 +4093,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
        __u64 blocks_count;
        int err = 0;
        ext4_group_t first_not_zeroed;
-       struct ext4_parsed_options parsed_opts;
+       struct ext4_fs_context parsed_opts;
 
        /* Set defaults for the variables that will be set during parsing */
        parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
@@ -5899,7 +5935,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
        char *to_free[EXT4_MAXQUOTAS];
 #endif
        char *orig_data = kstrdup(data, GFP_KERNEL);
-       struct ext4_parsed_options parsed_opts;
+       struct ext4_fs_context parsed_opts;
 
        parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
        parsed_opts.journal_devnum = 0;