From a96e9783e05851d5f06da0ae7635aec55a228e3d Mon Sep 17 00:00:00 2001 From: Lee Duncan Date: Thu, 14 Apr 2016 18:18:50 -0700 Subject: [PATCH] target: make target db location configurable This commit adds the read-write attribute "dbroot", in the top-level CONFIGFS (core) target directory, normally /sys/kernel/config/target. This attribute defaults to "/var/target" but can be changed by writing a new pathname string to it. Changing this attribute is only allowed when no fabric drivers are loaded and the supplied value specifies an existing directory. Target modules that care about the target database root directory will be modified to use this attribute in a future commit. Signed-off-by: Lee Duncan Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_configfs.c | 62 +++++++++++++++++++++++++++ drivers/target/target_core_internal.h | 6 +++ 2 files changed, 68 insertions(+) diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index d498533f09ee..73c23c75528a 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -99,6 +99,67 @@ static ssize_t target_core_item_version_show(struct config_item *item, CONFIGFS_ATTR_RO(target_core_item_, version); +char db_root[DB_ROOT_LEN] = DB_ROOT_DEFAULT; +static char db_root_stage[DB_ROOT_LEN]; + +static ssize_t target_core_item_dbroot_show(struct config_item *item, + char *page) +{ + return sprintf(page, "%s\n", db_root); +} + +static ssize_t target_core_item_dbroot_store(struct config_item *item, + const char *page, size_t count) +{ + ssize_t read_bytes; + struct file *fp; + + mutex_lock(&g_tf_lock); + if (!list_empty(&g_tf_list)) { + mutex_unlock(&g_tf_lock); + pr_err("db_root: cannot be changed: target drivers registered"); + return -EINVAL; + } + + if (count > (DB_ROOT_LEN - 1)) { + mutex_unlock(&g_tf_lock); + pr_err("db_root: count %d exceeds DB_ROOT_LEN-1: %u\n", + (int)count, DB_ROOT_LEN - 1); + return -EINVAL; + } + + read_bytes = snprintf(db_root_stage, DB_ROOT_LEN, "%s", page); + if (!read_bytes) { + mutex_unlock(&g_tf_lock); + return -EINVAL; + } + if (db_root_stage[read_bytes - 1] == '\n') + db_root_stage[read_bytes - 1] = '\0'; + + /* validate new db root before accepting it */ + fp = filp_open(db_root_stage, O_RDONLY, 0); + if (IS_ERR(fp)) { + mutex_unlock(&g_tf_lock); + pr_err("db_root: cannot open: %s\n", db_root_stage); + return -EINVAL; + } + if (!S_ISDIR(fp->f_inode->i_mode)) { + filp_close(fp, 0); + mutex_unlock(&g_tf_lock); + pr_err("db_root: not a directory: %s\n", db_root_stage); + return -EINVAL; + } + filp_close(fp, 0); + + strncpy(db_root, db_root_stage, read_bytes); + + mutex_unlock(&g_tf_lock); + + return read_bytes; +} + +CONFIGFS_ATTR(target_core_item_, dbroot); + static struct target_fabric_configfs *target_core_get_fabric( const char *name) { @@ -239,6 +300,7 @@ static struct configfs_group_operations target_core_fabric_group_ops = { */ static struct configfs_attribute *target_core_fabric_item_attrs[] = { &target_core_item_attr_version, + &target_core_item_attr_dbroot, NULL, }; diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h index 86b4a8375628..fc91e85f54ba 100644 --- a/drivers/target/target_core_internal.h +++ b/drivers/target/target_core_internal.h @@ -155,4 +155,10 @@ void target_stat_setup_mappedlun_default_groups(struct se_lun_acl *); /* target_core_xcopy.c */ extern struct se_portal_group xcopy_pt_tpg; +/* target_core_configfs.c */ +#define DB_ROOT_LEN 4096 +#define DB_ROOT_DEFAULT "/var/target" + +extern char db_root[]; + #endif /* TARGET_CORE_INTERNAL_H */ -- 2.20.1