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dm_table.c revision 1.20
      1  1.20    andvar /*        $NetBSD: dm_table.c,v 1.20 2021/08/20 20:25:27 andvar Exp $      */
      2   1.2      haad 
      3   1.2      haad /*
      4   1.2      haad  * Copyright (c) 2008 The NetBSD Foundation, Inc.
      5   1.2      haad  * All rights reserved.
      6   1.2      haad  *
      7   1.2      haad  * This code is derived from software contributed to The NetBSD Foundation
      8   1.2      haad  * by Adam Hamsik.
      9   1.2      haad  *
     10   1.2      haad  * Redistribution and use in source and binary forms, with or without
     11   1.2      haad  * modification, are permitted provided that the following conditions
     12   1.2      haad  * are met:
     13   1.2      haad  * 1. Redistributions of source code must retain the above copyright
     14   1.2      haad  *    notice, this list of conditions and the following disclaimer.
     15   1.2      haad  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.2      haad  *    notice, this list of conditions and the following disclaimer in the
     17   1.2      haad  *    documentation and/or other materials provided with the distribution.
     18   1.2      haad  *
     19   1.2      haad  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20   1.2      haad  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21   1.2      haad  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22   1.2      haad  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23   1.2      haad  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24   1.2      haad  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25   1.2      haad  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26   1.2      haad  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27   1.2      haad  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28   1.2      haad  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29   1.2      haad  * POSSIBILITY OF SUCH DAMAGE.
     30   1.2      haad  */
     31   1.8  christos #include <sys/cdefs.h>
     32  1.20    andvar __KERNEL_RCSID(0, "$NetBSD: dm_table.c,v 1.20 2021/08/20 20:25:27 andvar Exp $");
     33   1.2      haad 
     34   1.2      haad #include <sys/types.h>
     35   1.2      haad #include <sys/param.h>
     36   1.2      haad #include <sys/kmem.h>
     37   1.2      haad 
     38   1.2      haad #include "dm.h"
     39   1.2      haad 
     40   1.2      haad /*
     41   1.2      haad  * There are two types of users of this interface:
     42   1.5      haad  *
     43   1.2      haad  * a) Readers such as
     44   1.2      haad  *    dmstrategy, dmgetdisklabel, dmsize, dm_dev_status_ioctl,
     45   1.2      haad  *    dm_table_deps_ioctl, dm_table_status_ioctl, dm_table_reload_ioctl
     46   1.2      haad  *
     47   1.2      haad  * b) Writers such as
     48   1.2      haad  *    dm_dev_remove_ioctl, dm_dev_resume_ioctl, dm_table_clear_ioctl
     49   1.2      haad  *
     50   1.2      haad  * Writers can work with table_head only when there are no readers. I
     51   1.2      haad  * use reference counting on io_cnt.
     52   1.2      haad  *
     53   1.2      haad  */
     54   1.2      haad 
     55   1.5      haad static int dm_table_busy(dm_table_head_t *, uint8_t);
     56   1.2      haad static void dm_table_unbusy(dm_table_head_t *);
     57  1.17   tkusumi static void dm_table_free_deps(dm_table_entry_t *);
     58  1.17   tkusumi 
     59   1.2      haad 
     60   1.2      haad /*
     61   1.2      haad  * Function to increment table user reference counter. Return id
     62   1.2      haad  * of table_id table.
     63   1.2      haad  * DM_TABLE_ACTIVE will return active table id.
     64   1.2      haad  * DM_TABLE_INACTIVE will return inactive table id.
     65   1.2      haad  */
     66   1.2      haad static int
     67  1.12   tkusumi dm_table_busy(dm_table_head_t *head, uint8_t table_id)
     68   1.2      haad {
     69   1.2      haad 	uint8_t id;
     70   1.2      haad 
     71   1.2      haad 	mutex_enter(&head->table_mtx);
     72   1.2      haad 
     73   1.2      haad 	if (table_id == DM_TABLE_ACTIVE)
     74   1.2      haad 		id = head->cur_active_table;
     75   1.2      haad 	else
     76   1.2      haad 		id = 1 - head->cur_active_table;
     77   1.2      haad 
     78   1.2      haad 	head->io_cnt++;
     79   1.2      haad 
     80   1.2      haad 	mutex_exit(&head->table_mtx);
     81   1.2      haad 	return id;
     82   1.2      haad }
     83   1.8  christos 
     84   1.2      haad /*
     85   1.2      haad  * Function release table lock and eventually wakeup all waiters.
     86   1.2      haad  */
     87   1.2      haad static void
     88  1.12   tkusumi dm_table_unbusy(dm_table_head_t *head)
     89   1.2      haad {
     90  1.16   tkusumi 
     91   1.2      haad 	KASSERT(head->io_cnt != 0);
     92   1.2      haad 
     93   1.2      haad 	mutex_enter(&head->table_mtx);
     94   1.5      haad 
     95   1.2      haad 	if (--head->io_cnt == 0)
     96   1.2      haad 		cv_broadcast(&head->table_cv);
     97   1.5      haad 
     98   1.2      haad 	mutex_exit(&head->table_mtx);
     99   1.2      haad }
    100   1.8  christos 
    101   1.2      haad /*
    102   1.2      haad  * Return current active table to caller, increment io_cnt reference counter.
    103   1.2      haad  */
    104   1.2      haad dm_table_t *
    105  1.12   tkusumi dm_table_get_entry(dm_table_head_t *head, uint8_t table_id)
    106   1.2      haad {
    107   1.2      haad 	uint8_t id;
    108   1.2      haad 
    109   1.2      haad 	id = dm_table_busy(head, table_id);
    110   1.5      haad 
    111   1.2      haad 	return &head->tables[id];
    112   1.2      haad }
    113   1.2      haad /*
    114   1.2      haad  * Decrement io reference counter and wake up all callers, with table_head cv.
    115   1.2      haad  */
    116   1.2      haad void
    117  1.12   tkusumi dm_table_release(dm_table_head_t *head, uint8_t table_id)
    118   1.2      haad {
    119  1.16   tkusumi 
    120   1.2      haad 	dm_table_unbusy(head);
    121   1.2      haad }
    122   1.8  christos 
    123   1.2      haad /*
    124   1.2      haad  * Switch table from inactive to active mode. Have to wait until io_cnt is 0.
    125   1.2      haad  */
    126   1.2      haad void
    127  1.12   tkusumi dm_table_switch_tables(dm_table_head_t *head)
    128   1.2      haad {
    129  1.16   tkusumi 
    130   1.2      haad 	mutex_enter(&head->table_mtx);
    131   1.2      haad 
    132   1.2      haad 	while (head->io_cnt != 0)
    133   1.2      haad 		cv_wait(&head->table_cv, &head->table_mtx);
    134   1.2      haad 
    135   1.2      haad 	head->cur_active_table = 1 - head->cur_active_table;
    136   1.2      haad 
    137   1.2      haad 	mutex_exit(&head->table_mtx);
    138   1.2      haad }
    139   1.8  christos 
    140   1.2      haad /*
    141   1.2      haad  * Destroy all table data. This function can run when there are no
    142   1.2      haad  * readers on table lists.
    143   1.2      haad  *
    144   1.2      haad  * XXX Is it ok to call kmem_free and potentialy VOP_CLOSE with held mutex ?xs
    145   1.2      haad  */
    146   1.2      haad int
    147  1.12   tkusumi dm_table_destroy(dm_table_head_t *head, uint8_t table_id)
    148   1.2      haad {
    149   1.5      haad 	dm_table_t *tbl;
    150   1.2      haad 	dm_table_entry_t *table_en;
    151   1.2      haad 	uint8_t id;
    152   1.2      haad 
    153   1.2      haad 	mutex_enter(&head->table_mtx);
    154   1.2      haad 
    155   1.4     joerg 	aprint_debug("dm_Table_destroy called with %d--%d\n", table_id, head->io_cnt);
    156   1.4     joerg 
    157   1.2      haad 	while (head->io_cnt != 0)
    158   1.2      haad 		cv_wait(&head->table_cv, &head->table_mtx);
    159   1.2      haad 
    160   1.2      haad 	if (table_id == DM_TABLE_ACTIVE)
    161   1.2      haad 		id = head->cur_active_table;
    162   1.2      haad 	else
    163   1.2      haad 		id = 1 - head->cur_active_table;
    164   1.5      haad 
    165   1.2      haad 	tbl = &head->tables[id];
    166   1.5      haad 
    167  1.11   tkusumi 	while ((table_en = SLIST_FIRST(tbl)) != NULL) {
    168  1.11   tkusumi 		SLIST_REMOVE(tbl, table_en, dm_table_entry, next);
    169  1.10   tkusumi 		if (table_en->target->destroy(table_en) == 0)
    170  1.10   tkusumi 			table_en->target_config = NULL;
    171  1.17   tkusumi 		dm_table_free_deps(table_en);
    172   1.2      haad 		kmem_free(table_en, sizeof(*table_en));
    173   1.2      haad 	}
    174  1.11   tkusumi 	KASSERT(SLIST_EMPTY(tbl));
    175   1.2      haad 
    176   1.2      haad 	mutex_exit(&head->table_mtx);
    177   1.5      haad 
    178   1.2      haad 	return 0;
    179   1.2      haad }
    180   1.8  christos 
    181   1.2      haad /*
    182   1.2      haad  * Return length of active table in device.
    183   1.2      haad  */
    184  1.19   tkusumi static uint64_t
    185  1.12   tkusumi dm_table_size_impl(dm_table_head_t *head, int table)
    186   1.2      haad {
    187   1.5      haad 	dm_table_t *tbl;
    188   1.2      haad 	dm_table_entry_t *table_en;
    189   1.2      haad 	uint64_t length;
    190   1.2      haad 	uint8_t id;
    191   1.5      haad 
    192   1.2      haad 	length = 0;
    193   1.2      haad 
    194   1.7     ahoka 	id = dm_table_busy(head, table);
    195   1.5      haad 
    196   1.2      haad 	/* Select active table */
    197   1.2      haad 	tbl = &head->tables[id];
    198   1.5      haad 
    199   1.2      haad 	/*
    200   1.2      haad 	 * Find out what tables I want to select.
    201   1.2      haad 	 * if length => rawblkno then we should used that table.
    202   1.2      haad 	 */
    203   1.2      haad 	SLIST_FOREACH(table_en, tbl, next)
    204   1.9   tkusumi 		length += table_en->length;
    205   1.2      haad 
    206   1.2      haad 	dm_table_unbusy(head);
    207   1.5      haad 
    208   1.3  jakllsch 	return length;
    209   1.2      haad }
    210   1.7     ahoka 
    211   1.7     ahoka /*
    212   1.7     ahoka  * Return length of active table in device.
    213   1.7     ahoka  */
    214   1.7     ahoka uint64_t
    215  1.12   tkusumi dm_table_size(dm_table_head_t *head)
    216   1.7     ahoka {
    217  1.16   tkusumi 
    218   1.7     ahoka 	return dm_table_size_impl(head, DM_TABLE_ACTIVE);
    219   1.7     ahoka }
    220   1.7     ahoka 
    221   1.7     ahoka /*
    222   1.7     ahoka  * Return length of active table in device.
    223   1.7     ahoka  */
    224   1.7     ahoka uint64_t
    225  1.12   tkusumi dm_inactive_table_size(dm_table_head_t *head)
    226   1.7     ahoka {
    227  1.16   tkusumi 
    228   1.7     ahoka 	return dm_table_size_impl(head, DM_TABLE_INACTIVE);
    229   1.7     ahoka }
    230   1.7     ahoka 
    231   1.2      haad /*
    232   1.6   mlelstv  * Return combined disk geometry
    233   1.6   mlelstv  */
    234   1.6   mlelstv void
    235  1.16   tkusumi dm_table_disksize(dm_table_head_t *head, uint64_t *numsecp,
    236  1.16   tkusumi     unsigned int *secsizep)
    237   1.6   mlelstv {
    238   1.6   mlelstv 	dm_table_t *tbl;
    239   1.6   mlelstv 	dm_table_entry_t *table_en;
    240   1.6   mlelstv 	uint64_t length;
    241  1.14   tkusumi 	unsigned int secsize, tsecsize;
    242   1.6   mlelstv 	uint8_t id;
    243   1.6   mlelstv 
    244   1.6   mlelstv 	length = 0;
    245   1.6   mlelstv 
    246   1.6   mlelstv 	id = dm_table_busy(head, DM_TABLE_ACTIVE);
    247   1.6   mlelstv 
    248   1.6   mlelstv 	/* Select active table */
    249   1.6   mlelstv 	tbl = &head->tables[id];
    250   1.6   mlelstv 
    251   1.6   mlelstv 	/*
    252   1.6   mlelstv 	 * Find out what tables I want to select.
    253   1.6   mlelstv 	 * if length => rawblkno then we should used that table.
    254   1.6   mlelstv 	 */
    255   1.6   mlelstv 	secsize = 0;
    256   1.6   mlelstv 	SLIST_FOREACH(table_en, tbl, next) {
    257   1.9   tkusumi 		length += table_en->length;
    258  1.15   tkusumi 		if (table_en->target->secsize)
    259  1.15   tkusumi 			table_en->target->secsize(table_en, &tsecsize);
    260  1.15   tkusumi 		else
    261  1.15   tkusumi 			tsecsize = 0;
    262   1.9   tkusumi 		if (secsize < tsecsize)
    263   1.9   tkusumi 			secsize = tsecsize;
    264   1.6   mlelstv 	}
    265  1.18   tkusumi 
    266  1.18   tkusumi 	if (numsecp)
    267  1.18   tkusumi 		*numsecp = secsize > 0 ? dbtob(length) / secsize : 0;
    268  1.18   tkusumi 	if (secsizep)
    269  1.18   tkusumi 		*secsizep = secsize;
    270   1.6   mlelstv 
    271   1.6   mlelstv 	dm_table_unbusy(head);
    272   1.6   mlelstv }
    273   1.8  christos 
    274   1.6   mlelstv /*
    275   1.2      haad  * Return > 0 if table is at least one table entry (returns number of entries)
    276   1.2      haad  * and return 0 if there is not. Target count returned from this function
    277   1.2      haad  * doesn't need to be true when userspace user receive it (after return
    278   1.2      haad  * there can be dm_dev_resume_ioctl), therfore this isonly informative.
    279   1.2      haad  */
    280   1.2      haad int
    281  1.12   tkusumi dm_table_get_target_count(dm_table_head_t *head, uint8_t table_id)
    282   1.5      haad {
    283   1.2      haad 	dm_table_entry_t *table_en;
    284   1.2      haad 	dm_table_t *tbl;
    285   1.2      haad 	uint32_t target_count;
    286   1.2      haad 	uint8_t id;
    287   1.2      haad 
    288   1.2      haad 	target_count = 0;
    289   1.2      haad 
    290   1.2      haad 	id = dm_table_busy(head, table_id);
    291   1.2      haad 	tbl = &head->tables[id];
    292   1.2      haad 
    293   1.2      haad 	SLIST_FOREACH(table_en, tbl, next)
    294   1.9   tkusumi 		target_count++;
    295   1.2      haad 
    296   1.2      haad 	dm_table_unbusy(head);
    297   1.5      haad 
    298   1.2      haad 	return target_count;
    299   1.2      haad }
    300   1.2      haad 
    301   1.2      haad /*
    302   1.2      haad  * Initialize table_head structures, I'm trying to keep this structure as
    303   1.2      haad  * opaque as possible.
    304   1.2      haad  */
    305   1.2      haad void
    306  1.12   tkusumi dm_table_head_init(dm_table_head_t *head)
    307   1.2      haad {
    308  1.16   tkusumi 
    309   1.2      haad 	head->cur_active_table = 0;
    310   1.2      haad 	head->io_cnt = 0;
    311   1.5      haad 
    312   1.2      haad 	/* Initialize tables. */
    313   1.2      haad 	SLIST_INIT(&head->tables[0]);
    314   1.2      haad 	SLIST_INIT(&head->tables[1]);
    315   1.2      haad 
    316   1.2      haad 	mutex_init(&head->table_mtx, MUTEX_DEFAULT, IPL_NONE);
    317   1.2      haad 	cv_init(&head->table_cv, "dm_io");
    318   1.2      haad }
    319   1.8  christos 
    320   1.2      haad /*
    321   1.2      haad  * Destroy all variables in table_head
    322   1.2      haad  */
    323   1.2      haad void
    324  1.12   tkusumi dm_table_head_destroy(dm_table_head_t *head)
    325   1.2      haad {
    326  1.16   tkusumi 
    327   1.2      haad 	KASSERT(!mutex_owned(&head->table_mtx));
    328   1.2      haad 	KASSERT(!cv_has_waiters(&head->table_cv));
    329  1.20    andvar 	/* tables don't exist when I call this routine, therefore it
    330   1.5      haad 	 * doesn't make sense to have io_cnt != 0 */
    331   1.5      haad 	KASSERT(head->io_cnt == 0);
    332   1.5      haad 
    333   1.2      haad 	cv_destroy(&head->table_cv);
    334   1.2      haad 	mutex_destroy(&head->table_mtx);
    335   1.2      haad }
    336  1.17   tkusumi 
    337  1.17   tkusumi int
    338  1.17   tkusumi dm_table_add_deps(dm_table_entry_t *table_en, dm_pdev_t *pdev)
    339  1.17   tkusumi {
    340  1.17   tkusumi 	dm_table_head_t *head;
    341  1.17   tkusumi 	dm_mapping_t *map;
    342  1.17   tkusumi 
    343  1.17   tkusumi 	if (!pdev)
    344  1.17   tkusumi 		return -1;
    345  1.17   tkusumi 
    346  1.17   tkusumi 	head = &table_en->dm_dev->table_head;
    347  1.17   tkusumi 	mutex_enter(&head->table_mtx);
    348  1.17   tkusumi 
    349  1.17   tkusumi 	TAILQ_FOREACH(map, &table_en->pdev_maps, next) {
    350  1.17   tkusumi 		if (map->data.pdev->pdev_vnode->v_rdev ==
    351  1.17   tkusumi 		    pdev->pdev_vnode->v_rdev) {
    352  1.17   tkusumi 			mutex_exit(&head->table_mtx);
    353  1.17   tkusumi 			return -1;
    354  1.17   tkusumi 		}
    355  1.17   tkusumi 	}
    356  1.17   tkusumi 
    357  1.17   tkusumi 	map = kmem_alloc(sizeof(*map), KM_SLEEP);
    358  1.17   tkusumi 	map->data.pdev = pdev;
    359  1.17   tkusumi 	aprint_debug("%s: %s\n", __func__, pdev->name);
    360  1.17   tkusumi 	TAILQ_INSERT_TAIL(&table_en->pdev_maps, map, next);
    361  1.17   tkusumi 
    362  1.17   tkusumi 	mutex_exit(&head->table_mtx);
    363  1.17   tkusumi 
    364  1.17   tkusumi 	return 0;
    365  1.17   tkusumi }
    366  1.17   tkusumi 
    367  1.17   tkusumi /* caller must hold ->table_mtx */
    368  1.17   tkusumi static void
    369  1.17   tkusumi dm_table_free_deps(dm_table_entry_t *table_en)
    370  1.17   tkusumi {
    371  1.17   tkusumi 	dm_mapping_t *map;
    372  1.17   tkusumi 
    373  1.17   tkusumi 	while ((map = TAILQ_FIRST(&table_en->pdev_maps)) != NULL) {
    374  1.17   tkusumi 		TAILQ_REMOVE(&table_en->pdev_maps, map, next);
    375  1.17   tkusumi 		aprint_debug("%s: %s\n", __func__, map->data.pdev->name);
    376  1.17   tkusumi 		kmem_free(map, sizeof(*map));
    377  1.17   tkusumi 	}
    378  1.17   tkusumi 	KASSERT(TAILQ_EMPTY(&table_en->pdev_maps));
    379  1.17   tkusumi }
    380