diff options
Diffstat (limited to 'fs/fs_context.c')
| -rw-r--r-- | fs/fs_context.c | 158 |
1 files changed, 115 insertions, 43 deletions
diff --git a/fs/fs_context.c b/fs/fs_context.c index 7d5c5dd2b1d5..93b7ebf8d927 100644 --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -80,6 +80,35 @@ static int vfs_parse_sb_flag(struct fs_context *fc, const char *key) } /** + * vfs_parse_fs_param_source - Handle setting "source" via parameter + * @fc: The filesystem context to modify + * @param: The parameter + * + * This is a simple helper for filesystems to verify that the "source" they + * accept is sane. + * + * Returns 0 on success, -ENOPARAM if this is not "source" parameter, and + * -EINVAL otherwise. In the event of failure, supplementary error information + * is logged. + */ +int vfs_parse_fs_param_source(struct fs_context *fc, struct fs_parameter *param) +{ + if (strcmp(param->key, "source") != 0) + return -ENOPARAM; + + if (param->type != fs_value_is_string) + return invalf(fc, "Non-string source"); + + if (fc->source) + return invalf(fc, "Multiple sources"); + + fc->source = param->string; + param->string = NULL; + return 0; +} +EXPORT_SYMBOL(vfs_parse_fs_param_source); + +/** * vfs_parse_fs_param - Add a single parameter to a superblock config * @fc: The filesystem context to modify * @param: The parameter @@ -122,15 +151,9 @@ int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param) /* If the filesystem doesn't take any arguments, give it the * default handling of source. */ - if (strcmp(param->key, "source") == 0) { - if (param->type != fs_value_is_string) - return invalf(fc, "VFS: Non-string source"); - if (fc->source) - return invalf(fc, "VFS: Multiple sources"); - fc->source = param->string; - param->string = NULL; - return 0; - } + ret = vfs_parse_fs_param_source(fc, param); + if (ret != -ENOPARAM) + return ret; return invalf(fc, "%s: Unknown parameter '%s'", fc->fs_type->name, param->key); @@ -138,21 +161,24 @@ int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param) EXPORT_SYMBOL(vfs_parse_fs_param); /** - * vfs_parse_fs_string - Convenience function to just parse a string. + * vfs_parse_fs_qstr - Convenience function to just parse a string. + * @fc: Filesystem context. + * @key: Parameter name. + * @value: Default value. */ -int vfs_parse_fs_string(struct fs_context *fc, const char *key, - const char *value, size_t v_size) +int vfs_parse_fs_qstr(struct fs_context *fc, const char *key, + const struct qstr *value) { int ret; struct fs_parameter param = { .key = key, .type = fs_value_is_flag, - .size = v_size, + .size = value ? value->len : 0, }; if (value) { - param.string = kmemdup_nul(value, v_size, GFP_KERNEL); + param.string = kmemdup_nul(value->name, value->len, GFP_KERNEL); if (!param.string) return -ENOMEM; param.type = fs_value_is_string; @@ -162,20 +188,22 @@ int vfs_parse_fs_string(struct fs_context *fc, const char *key, kfree(param.string); return ret; } -EXPORT_SYMBOL(vfs_parse_fs_string); +EXPORT_SYMBOL(vfs_parse_fs_qstr); /** - * generic_parse_monolithic - Parse key[=val][,key[=val]]* mount data - * @ctx: The superblock configuration to fill in. + * vfs_parse_monolithic_sep - Parse key[=val][,key[=val]]* mount data + * @fc: The superblock configuration to fill in. * @data: The data to parse + * @sep: callback for separating next option * - * Parse a blob of data that's in key[=val][,key[=val]]* form. This can be - * called from the ->monolithic_mount_data() fs_context operation. + * Parse a blob of data that's in key[=val][,key[=val]]* form with a custom + * option separator callback. * * Returns 0 on success or the error returned by the ->parse_option() fs_context * operation on failure. */ -int generic_parse_monolithic(struct fs_context *fc, void *data) +int vfs_parse_monolithic_sep(struct fs_context *fc, void *data, + char *(*sep)(char **)) { char *options = data, *key; int ret = 0; @@ -187,18 +215,16 @@ int generic_parse_monolithic(struct fs_context *fc, void *data) if (ret) return ret; - while ((key = strsep(&options, ",")) != NULL) { + while ((key = sep(&options)) != NULL) { if (*key) { - size_t v_len = 0; char *value = strchr(key, '='); if (value) { - if (value == key) + if (unlikely(value == key)) continue; *value++ = 0; - v_len = strlen(value); } - ret = vfs_parse_fs_string(fc, key, value, v_len); + ret = vfs_parse_fs_string(fc, key, value); if (ret < 0) break; } @@ -206,6 +232,28 @@ int generic_parse_monolithic(struct fs_context *fc, void *data) return ret; } +EXPORT_SYMBOL(vfs_parse_monolithic_sep); + +static char *vfs_parse_comma_sep(char **s) +{ + return strsep(s, ","); +} + +/** + * generic_parse_monolithic - Parse key[=val][,key[=val]]* mount data + * @fc: The superblock configuration to fill in. + * @data: The data to parse + * + * Parse a blob of data that's in key[=val][,key[=val]]* form. This can be + * called from the ->monolithic_mount_data() fs_context operation. + * + * Returns 0 on success or the error returned by the ->parse_option() fs_context + * operation on failure. + */ +int generic_parse_monolithic(struct fs_context *fc, void *data) +{ + return vfs_parse_monolithic_sep(fc, data, vfs_parse_comma_sep); +} EXPORT_SYMBOL(generic_parse_monolithic); /** @@ -231,7 +279,7 @@ static struct fs_context *alloc_fs_context(struct file_system_type *fs_type, struct fs_context *fc; int ret = -ENOMEM; - fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL); + fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL_ACCOUNT); if (!fc) return ERR_PTR(-ENOMEM); @@ -292,10 +340,31 @@ struct fs_context *fs_context_for_reconfigure(struct dentry *dentry, } EXPORT_SYMBOL(fs_context_for_reconfigure); +/** + * fs_context_for_submount: allocate a new fs_context for a submount + * @type: file_system_type of the new context + * @reference: reference dentry from which to copy relevant info + * + * Allocate a new fs_context suitable for a submount. This also ensures that + * the fc->security object is inherited from @reference (if needed). + */ struct fs_context *fs_context_for_submount(struct file_system_type *type, struct dentry *reference) { - return alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT); + struct fs_context *fc; + int ret; + + fc = alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT); + if (IS_ERR(fc)) + return fc; + + ret = security_fs_context_submount(fc, reference->d_sb); + if (ret) { + put_fs_context(fc); + return ERR_PTR(ret); + } + + return fc; } EXPORT_SYMBOL(fs_context_for_submount); @@ -310,7 +379,7 @@ void fc_drop_locked(struct fs_context *fc) static void legacy_fs_context_free(struct fs_context *fc); /** - * vfs_dup_fc_config: Duplicate a filesystem context. + * vfs_dup_fs_context - Duplicate a filesystem context. * @src_fc: The context to copy. */ struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc) @@ -356,7 +425,9 @@ EXPORT_SYMBOL(vfs_dup_fs_context); /** * logfc - Log a message to a filesystem context - * @fc: The filesystem context to log to. + * @log: The filesystem context to log to, or NULL to use printk. + * @prefix: A string to prefix the output with, or NULL. + * @level: 'w' for a warning, 'e' for an error. Anything else is a notice. * @fmt: The format of the buffer. */ void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...) @@ -375,6 +446,10 @@ void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, printk(KERN_ERR "%s%s%pV\n", prefix ? prefix : "", prefix ? ": " : "", &vaf); break; + case 'i': + printk(KERN_INFO "%s%s%pV\n", prefix ? prefix : "", + prefix ? ": " : "", &vaf); + break; default: printk(KERN_NOTICE "%s%s%pV\n", prefix ? prefix : "", prefix ? ": " : "", &vaf); @@ -419,7 +494,7 @@ static void put_fc_log(struct fs_context *fc) if (log) { if (refcount_dec_and_test(&log->usage)) { fc->log.log = NULL; - for (i = 0; i <= 7; i++) + for (i = 0; i < ARRAY_SIZE(log->buffer) ; i++) if (log->need_free & (1 << i)) kfree(log->buffer[i]); kfree(log); @@ -504,16 +579,11 @@ static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param) struct legacy_fs_context *ctx = fc->fs_private; unsigned int size = ctx->data_size; size_t len = 0; + int ret; - if (strcmp(param->key, "source") == 0) { - if (param->type != fs_value_is_string) - return invalf(fc, "VFS: Legacy: Non-string source"); - if (fc->source) - return invalf(fc, "VFS: Legacy: Multiple sources"); - fc->source = param->string; - param->string = NULL; - return 0; - } + ret = vfs_parse_fs_param_source(fc, param); + if (ret != -ENOPARAM) + return ret; if (ctx->param_type == LEGACY_FS_MONOLITHIC_PARAMS) return invalf(fc, "VFS: Legacy: Can't mix monolithic and individual options"); @@ -521,7 +591,7 @@ static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param) switch (param->type) { case fs_value_is_string: len = 1 + param->size; - /* Fall through */ + fallthrough; case fs_value_is_flag: len += strlen(param->key); break; @@ -530,7 +600,7 @@ static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param) param->key); } - if (len > PAGE_SIZE - 2 - size) + if (size + len + 2 > PAGE_SIZE) return invalf(fc, "VFS: Legacy: Cumulative options too large"); if (strchr(param->key, ',') || (param->type == fs_value_is_string && @@ -543,7 +613,8 @@ static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param) return -ENOMEM; } - ctx->legacy_data[size++] = ','; + if (size) + ctx->legacy_data[size++] = ','; len = strlen(param->key); memcpy(ctx->legacy_data + size, param->key, len); size += len; @@ -631,7 +702,7 @@ const struct fs_context_operations legacy_fs_context_ops = { */ static int legacy_init_fs_context(struct fs_context *fc) { - fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL); + fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL_ACCOUNT); if (!fc->fs_private) return -ENOMEM; fc->ops = &legacy_fs_context_ops; @@ -673,6 +744,7 @@ void vfs_clean_context(struct fs_context *fc) security_free_mnt_opts(&fc->security); kfree(fc->source); fc->source = NULL; + fc->exclusive = false; fc->purpose = FS_CONTEXT_FOR_RECONFIGURE; fc->phase = FS_CONTEXT_AWAITING_RECONF; |