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Diffstat (limited to 'plugin/disks/information_schema_disks.cc')
| -rw-r--r-- | plugin/disks/information_schema_disks.cc | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/plugin/disks/information_schema_disks.cc b/plugin/disks/information_schema_disks.cc new file mode 100644 index 00000000..042cfaff --- /dev/null +++ b/plugin/disks/information_schema_disks.cc @@ -0,0 +1,164 @@ +/* + Copyright (c) 2017, 2019, MariaDB + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */ + +#include <my_global.h> +#include <sys/statvfs.h> +#include <sys/types.h> +#include <mntent.h> +#include <sql_class.h> +#include <sql_i_s.h> +#include <sql_acl.h> /* check_global_access() */ + +bool schema_table_store_record(THD *thd, TABLE *table); + + +struct st_mysql_information_schema disks_table_info = { MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION }; + + +namespace Show { + +ST_FIELD_INFO disks_table_fields[]= +{ + Column("Disk", Varchar(PATH_MAX), NOT_NULL), + Column("Path", Varchar(PATH_MAX), NOT_NULL), + Column("Total", SLonglong(32), NOT_NULL), // Total amount available + Column("Used", SLonglong(32), NOT_NULL), // Amount of space used + Column("Available", SLonglong(32), NOT_NULL), // Amount available to users other than root. + CEnd() +}; + + + +int disks_table_add_row(THD* pThd, + TABLE* pTable, + const char* zDisk, + const char* zPath, + const struct statvfs& info) +{ + // From: http://pubs.opengroup.org/onlinepubs/009695399/basedefs/sys/statvfs.h.html + // + // f_frsize Fundamental file system block size. + // f_blocks Total number of blocks on file system in units of f_frsize. + // f_bfree Total number of free blocks. + // f_bavail Number of free blocks available to non-privileged process. + + ulonglong total = ((ulonglong)info.f_frsize * info.f_blocks) / 1024; + ulonglong used = ((ulonglong)info.f_frsize * + (info.f_blocks - info.f_bfree)) / 1024; + ulonglong avail = ((ulonglong)info.f_frsize * info.f_bavail) / 1024; + + pTable->field[0]->store(zDisk, strlen(zDisk), system_charset_info); + pTable->field[1]->store(zPath, strlen(zPath), system_charset_info); + pTable->field[2]->store(total); + pTable->field[3]->store(used); + pTable->field[4]->store(avail); + + // 0 means success. + return (schema_table_store_record(pThd, pTable) != 0) ? 1 : 0; +} + +int disks_table_add_row(THD* pThd, TABLE* pTable, const char* zDisk, const char* zPath) +{ + int rv = 0; + + struct statvfs info; + + if (statvfs(zPath, &info) == 0) // We ignore failures. + { + rv = disks_table_add_row(pThd, pTable, zDisk, zPath, info); + } + + return rv; +} + +int disks_fill_table(THD* pThd, TABLE_LIST* pTables, Item* pCond) +{ + int rv = 1; + TABLE* pTable = pTables->table; + + if (check_global_access(pThd, FILE_ACL, true)) + return 0; + + FILE* pFile = setmntent("/etc/mtab", "r"); + + if (pFile) + { + const size_t BUFFER_SIZE = 4096; // 4K should be sufficient. + + char* pBuffer = new (std::nothrow) char [BUFFER_SIZE]; + + if (pBuffer) + { + rv = 0; + + struct mntent ent; + struct mntent* pEnt; + + while ((rv == 0) && (pEnt = getmntent_r(pFile, &ent, pBuffer, BUFFER_SIZE))) + { + // We only report the ones that refer to physical disks. + if (pEnt->mnt_fsname[0] == '/') + { + rv = disks_table_add_row(pThd, pTable, pEnt->mnt_fsname, pEnt->mnt_dir); + } + } + + delete [] pBuffer; + } + else + { + rv = 1; + } + + endmntent(pFile); + } + + return rv; +} + +int disks_table_init(void *ptr) +{ + ST_SCHEMA_TABLE* pSchema_table = (ST_SCHEMA_TABLE*)ptr; + + pSchema_table->fields_info = disks_table_fields; + pSchema_table->fill_table = disks_fill_table; + return 0; +} + +} // namespace Show + +extern "C" +{ + +maria_declare_plugin(disks) +{ + MYSQL_INFORMATION_SCHEMA_PLUGIN, + &disks_table_info, /* type-specific descriptor */ + "DISKS", /* table name */ + "Johan Wikman", /* author */ + "Disk space information", /* description */ + PLUGIN_LICENSE_GPL, /* license type */ + Show::disks_table_init, /* init function */ + NULL, /* deinit function */ + 0x0101, /* version = 1.1 */ + NULL, /* no status variables */ + NULL, /* no system variables */ + "1.1", /* String version representation */ + MariaDB_PLUGIN_MATURITY_STABLE /* Maturity (see include/mysql/plugin.h)*/ +} +mysql_declare_plugin_end; + +} |