2429 lines
56 KiB
C
2429 lines
56 KiB
C
![]() |
/*
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* Copyright (C) 2011 Red Hat UK.
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*
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* This file is released under the GPL.
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*/
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#include "dm-thin-metadata.h"
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#include <linux/device-mapper.h>
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#include <linux/dm-io.h>
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#include <linux/dm-kcopyd.h>
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#include <linux/list.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#define DM_MSG_PREFIX "thin"
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/*
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* Tunable constants
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*/
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#define ENDIO_HOOK_POOL_SIZE 10240
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#define DEFERRED_SET_SIZE 64
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#define MAPPING_POOL_SIZE 1024
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#define PRISON_CELLS 1024
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/*
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* The block size of the device holding pool data must be
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* between 64KB and 1GB.
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*/
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#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
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#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
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/*
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* The metadata device is currently limited in size. The limitation is
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* checked lower down in dm-space-map-metadata, but we also check it here
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* so we can fail early.
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*
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* We have one block of index, which can hold 255 index entries. Each
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* index entry contains allocation info about 16k metadata blocks.
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*/
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#define METADATA_DEV_MAX_SECTORS (255 * (1 << 14) * (THIN_METADATA_BLOCK_SIZE / (1 << SECTOR_SHIFT)))
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/*
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* Device id is restricted to 24 bits.
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*/
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#define MAX_DEV_ID ((1 << 24) - 1)
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/*
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* How do we handle breaking sharing of data blocks?
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* =================================================
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*
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* We use a standard copy-on-write btree to store the mappings for the
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* devices (note I'm talking about copy-on-write of the metadata here, not
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* the data). When you take an internal snapshot you clone the root node
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* of the origin btree. After this there is no concept of an origin or a
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* snapshot. They are just two device trees that happen to point to the
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* same data blocks.
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*
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* When we get a write in we decide if it's to a shared data block using
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* some timestamp magic. If it is, we have to break sharing.
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*
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* Let's say we write to a shared block in what was the origin. The
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* steps are:
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*
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* i) plug io further to this physical block. (see bio_prison code).
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*
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* ii) quiesce any read io to that shared data block. Obviously
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* including all devices that share this block. (see deferred_set code)
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*
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* iii) copy the data block to a newly allocate block. This step can be
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* missed out if the io covers the block. (schedule_copy).
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*
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* iv) insert the new mapping into the origin's btree
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* (process_prepared_mappings). This act of inserting breaks some
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* sharing of btree nodes between the two devices. Breaking sharing only
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* effects the btree of that specific device. Btrees for the other
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* devices that share the block never change. The btree for the origin
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* device as it was after the last commit is untouched, ie. we're using
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* persistent data structures in the functional programming sense.
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*
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* v) unplug io to this physical block, including the io that triggered
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* the breaking of sharing.
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*
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* Steps (ii) and (iii) occur in parallel.
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*
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* The metadata _doesn't_ need to be committed before the io continues. We
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* get away with this because the io is always written to a _new_ block.
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* If there's a crash, then:
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*
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* - The origin mapping will point to the old origin block (the shared
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* one). This will contain the data as it was before the io that triggered
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* the breaking of sharing came in.
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*
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* - The snap mapping still points to the old block. As it would after
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* the commit.
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*
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* The downside of this scheme is the timestamp magic isn't perfect, and
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* will continue to think that data block in the snapshot device is shared
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* even after the write to the origin has broken sharing. I suspect data
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* blocks will typically be shared by many different devices, so we're
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* breaking sharing n + 1 times, rather than n, where n is the number of
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* devices that reference this data block. At the moment I think the
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* benefits far, far outweigh the disadvantages.
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*/
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/*----------------------------------------------------------------*/
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/*
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* Sometimes we can't deal with a bio straight away. We put them in prison
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* where they can't cause any mischief. Bios are put in a cell identified
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* by a key, multiple bios can be in the same cell. When the cell is
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* subsequently unlocked the bios become available.
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*/
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struct bio_prison;
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struct cell_key {
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int virtual;
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dm_thin_id dev;
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dm_block_t block;
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};
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struct cell {
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struct hlist_node list;
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struct bio_prison *prison;
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struct cell_key key;
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unsigned count;
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struct bio_list bios;
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};
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struct bio_prison {
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spinlock_t lock;
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mempool_t *cell_pool;
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unsigned nr_buckets;
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unsigned hash_mask;
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struct hlist_head *cells;
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};
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static uint32_t calc_nr_buckets(unsigned nr_cells)
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{
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uint32_t n = 128;
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nr_cells /= 4;
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nr_cells = min(nr_cells, 8192u);
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while (n < nr_cells)
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n <<= 1;
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return n;
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}
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/*
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* @nr_cells should be the number of cells you want in use _concurrently_.
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* Don't confuse it with the number of distinct keys.
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*/
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static struct bio_prison *prison_create(unsigned nr_cells)
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{
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unsigned i;
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uint32_t nr_buckets = calc_nr_buckets(nr_cells);
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size_t len = sizeof(struct bio_prison) +
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(sizeof(struct hlist_head) * nr_buckets);
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struct bio_prison *prison = kmalloc(len, GFP_KERNEL);
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if (!prison)
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return NULL;
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spin_lock_init(&prison->lock);
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prison->cell_pool = mempool_create_kmalloc_pool(nr_cells,
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sizeof(struct cell));
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if (!prison->cell_pool) {
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kfree(prison);
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return NULL;
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}
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prison->nr_buckets = nr_buckets;
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prison->hash_mask = nr_buckets - 1;
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prison->cells = (struct hlist_head *) (prison + 1);
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for (i = 0; i < nr_buckets; i++)
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INIT_HLIST_HEAD(prison->cells + i);
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return prison;
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}
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static void prison_destroy(struct bio_prison *prison)
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{
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mempool_destroy(prison->cell_pool);
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kfree(prison);
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}
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static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key)
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{
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const unsigned long BIG_PRIME = 4294967291UL;
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uint64_t hash = key->block * BIG_PRIME;
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return (uint32_t) (hash & prison->hash_mask);
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}
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static int keys_equal(struct cell_key *lhs, struct cell_key *rhs)
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{
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return (lhs->virtual == rhs->virtual) &&
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(lhs->dev == rhs->dev) &&
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(lhs->block == rhs->block);
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}
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static struct cell *__search_bucket(struct hlist_head *bucket,
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struct cell_key *key)
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{
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struct cell *cell;
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struct hlist_node *tmp;
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hlist_for_each_entry(cell, tmp, bucket, list)
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if (keys_equal(&cell->key, key))
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return cell;
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return NULL;
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}
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/*
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* This may block if a new cell needs allocating. You must ensure that
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* cells will be unlocked even if the calling thread is blocked.
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*
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* Returns the number of entries in the cell prior to the new addition
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* or < 0 on failure.
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*/
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static int bio_detain(struct bio_prison *prison, struct cell_key *key,
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struct bio *inmate, struct cell **ref)
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{
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int r;
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unsigned long flags;
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uint32_t hash = hash_key(prison, key);
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struct cell *uninitialized_var(cell), *cell2 = NULL;
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BUG_ON(hash > prison->nr_buckets);
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spin_lock_irqsave(&prison->lock, flags);
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cell = __search_bucket(prison->cells + hash, key);
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if (!cell) {
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/*
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* Allocate a new cell
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*/
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spin_unlock_irqrestore(&prison->lock, flags);
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cell2 = mempool_alloc(prison->cell_pool, GFP_NOIO);
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spin_lock_irqsave(&prison->lock, flags);
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/*
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* We've been unlocked, so we have to double check that
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* nobody else has inserted this cell in the meantime.
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*/
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cell = __search_bucket(prison->cells + hash, key);
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if (!cell) {
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cell = cell2;
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cell2 = NULL;
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cell->prison = prison;
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memcpy(&cell->key, key, sizeof(cell->key));
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cell->count = 0;
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bio_list_init(&cell->bios);
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hlist_add_head(&cell->list, prison->cells + hash);
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}
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}
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r = cell->count++;
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bio_list_add(&cell->bios, inmate);
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spin_unlock_irqrestore(&prison->lock, flags);
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if (cell2)
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mempool_free(cell2, prison->cell_pool);
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*ref = cell;
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return r;
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}
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/*
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* @inmates must have been initialised prior to this call
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*/
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static void __cell_release(struct cell *cell, struct bio_list *inmates)
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{
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struct bio_prison *prison = cell->prison;
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hlist_del(&cell->list);
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if (inmates)
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bio_list_merge(inmates, &cell->bios);
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mempool_free(cell, prison->cell_pool);
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}
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static void cell_release(struct cell *cell, struct bio_list *bios)
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{
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unsigned long flags;
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struct bio_prison *prison = cell->prison;
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spin_lock_irqsave(&prison->lock, flags);
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__cell_release(cell, bios);
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spin_unlock_irqrestore(&prison->lock, flags);
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}
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/*
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* There are a couple of places where we put a bio into a cell briefly
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* before taking it out again. In these situations we know that no other
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* bio may be in the cell. This function releases the cell, and also does
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* a sanity check.
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*/
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static void cell_release_singleton(struct cell *cell, struct bio *bio)
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{
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struct bio_prison *prison = cell->prison;
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struct bio_list bios;
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struct bio *b;
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unsigned long flags;
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bio_list_init(&bios);
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spin_lock_irqsave(&prison->lock, flags);
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__cell_release(cell, &bios);
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spin_unlock_irqrestore(&prison->lock, flags);
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b = bio_list_pop(&bios);
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BUG_ON(b != bio);
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BUG_ON(!bio_list_empty(&bios));
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}
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static void cell_error(struct cell *cell)
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{
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struct bio_prison *prison = cell->prison;
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struct bio_list bios;
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struct bio *bio;
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unsigned long flags;
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bio_list_init(&bios);
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spin_lock_irqsave(&prison->lock, flags);
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__cell_release(cell, &bios);
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spin_unlock_irqrestore(&prison->lock, flags);
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while ((bio = bio_list_pop(&bios)))
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bio_io_error(bio);
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}
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/*----------------------------------------------------------------*/
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/*
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* We use the deferred set to keep track of pending reads to shared blocks.
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* We do this to ensure the new mapping caused by a write isn't performed
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* until these prior reads have completed. Otherwise the insertion of the
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* new mapping could free the old block that the read bios are mapped to.
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*/
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struct deferred_set;
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struct deferred_entry {
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struct deferred_set *ds;
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unsigned count;
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struct list_head work_items;
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};
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struct deferred_set {
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spinlock_t lock;
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unsigned current_entry;
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unsigned sweeper;
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struct deferred_entry entries[DEFERRED_SET_SIZE];
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};
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static void ds_init(struct deferred_set *ds)
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{
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int i;
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spin_lock_init(&ds->lock);
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ds->current_entry = 0;
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ds->sweeper = 0;
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for (i = 0; i < DEFERRED_SET_SIZE; i++) {
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ds->entries[i].ds = ds;
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ds->entries[i].count = 0;
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INIT_LIST_HEAD(&ds->entries[i].work_items);
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}
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}
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static struct deferred_entry *ds_inc(struct deferred_set *ds)
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{
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unsigned long flags;
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struct deferred_entry *entry;
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spin_lock_irqsave(&ds->lock, flags);
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entry = ds->entries + ds->current_entry;
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entry->count++;
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spin_unlock_irqrestore(&ds->lock, flags);
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return entry;
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}
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static unsigned ds_next(unsigned index)
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{
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return (index + 1) % DEFERRED_SET_SIZE;
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}
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static void __sweep(struct deferred_set *ds, struct list_head *head)
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{
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while ((ds->sweeper != ds->current_entry) &&
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!ds->entries[ds->sweeper].count) {
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list_splice_init(&ds->entries[ds->sweeper].work_items, head);
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ds->sweeper = ds_next(ds->sweeper);
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}
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if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count)
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list_splice_init(&ds->entries[ds->sweeper].work_items, head);
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}
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static void ds_dec(struct deferred_entry *entry, struct list_head *head)
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{
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unsigned long flags;
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spin_lock_irqsave(&entry->ds->lock, flags);
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BUG_ON(!entry->count);
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--entry->count;
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__sweep(entry->ds, head);
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spin_unlock_irqrestore(&entry->ds->lock, flags);
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}
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|
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/*
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* Returns 1 if deferred or 0 if no pending items to delay job.
|
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*/
|
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static int ds_add_work(struct deferred_set *ds, struct list_head *work)
|
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{
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int r = 1;
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unsigned long flags;
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unsigned next_entry;
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spin_lock_irqsave(&ds->lock, flags);
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if ((ds->sweeper == ds->current_entry) &&
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!ds->entries[ds->current_entry].count)
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r = 0;
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else {
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list_add(work, &ds->entries[ds->current_entry].work_items);
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next_entry = ds_next(ds->current_entry);
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if (!ds->entries[next_entry].count)
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ds->current_entry = next_entry;
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}
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spin_unlock_irqrestore(&ds->lock, flags);
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return r;
|
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}
|
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|
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/*----------------------------------------------------------------*/
|
||
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|
||
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/*
|
||
|
* Key building.
|
||
|
*/
|
||
|
static void build_data_key(struct dm_thin_device *td,
|
||
|
dm_block_t b, struct cell_key *key)
|
||
|
{
|
||
|
key->virtual = 0;
|
||
|
key->dev = dm_thin_dev_id(td);
|
||
|
key->block = b;
|
||
|
}
|
||
|
|
||
|
static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
|
||
|
struct cell_key *key)
|
||
|
{
|
||
|
key->virtual = 1;
|
||
|
key->dev = dm_thin_dev_id(td);
|
||
|
key->block = b;
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------*/
|
||
|
|
||
|
/*
|
||
|
* A pool device ties together a metadata device and a data device. It
|
||
|
* also provides the interface for creating and destroying internal
|
||
|
* devices.
|
||
|
*/
|
||
|
struct new_mapping;
|
||
|
struct pool {
|
||
|
struct list_head list;
|
||
|
struct dm_target *ti; /* Only set if a pool target is bound */
|
||
|
|
||
|
struct mapped_device *pool_md;
|
||
|
struct block_device *md_dev;
|
||
|
struct dm_pool_metadata *pmd;
|
||
|
|
||
|
uint32_t sectors_per_block;
|
||
|
unsigned block_shift;
|
||
|
dm_block_t offset_mask;
|
||
|
dm_block_t low_water_blocks;
|
||
|
|
||
|
unsigned zero_new_blocks:1;
|
||
|
unsigned low_water_triggered:1; /* A dm event has been sent */
|
||
|
unsigned no_free_space:1; /* A -ENOSPC warning has been issued */
|
||
|
|
||
|
struct bio_prison *prison;
|
||
|
struct dm_kcopyd_client *copier;
|
||
|
|
||
|
struct workqueue_struct *wq;
|
||
|
struct work_struct worker;
|
||
|
|
||
|
unsigned ref_count;
|
||
|
|
||
|
spinlock_t lock;
|
||
|
struct bio_list deferred_bios;
|
||
|
struct bio_list deferred_flush_bios;
|
||
|
struct list_head prepared_mappings;
|
||
|
|
||
|
struct bio_list retry_on_resume_list;
|
||
|
|
||
|
struct deferred_set ds; /* FIXME: move to thin_c */
|
||
|
|
||
|
struct new_mapping *next_mapping;
|
||
|
mempool_t *mapping_pool;
|
||
|
mempool_t *endio_hook_pool;
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* Target context for a pool.
|
||
|
*/
|
||
|
struct pool_c {
|
||
|
struct dm_target *ti;
|
||
|
struct pool *pool;
|
||
|
struct dm_dev *data_dev;
|
||
|
struct dm_dev *metadata_dev;
|
||
|
struct dm_target_callbacks callbacks;
|
||
|
|
||
|
dm_block_t low_water_blocks;
|
||
|
unsigned zero_new_blocks:1;
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* Target context for a thin.
|
||
|
*/
|
||
|
struct thin_c {
|
||
|
struct dm_dev *pool_dev;
|
||
|
dm_thin_id dev_id;
|
||
|
|
||
|
struct pool *pool;
|
||
|
struct dm_thin_device *td;
|
||
|
};
|
||
|
|
||
|
/*----------------------------------------------------------------*/
|
||
|
|
||
|
/*
|
||
|
* A global list of pools that uses a struct mapped_device as a key.
|
||
|
*/
|
||
|
static struct dm_thin_pool_table {
|
||
|
struct mutex mutex;
|
||
|
struct list_head pools;
|
||
|
} dm_thin_pool_table;
|
||
|
|
||
|
static void pool_table_init(void)
|
||
|
{
|
||
|
mutex_init(&dm_thin_pool_table.mutex);
|
||
|
INIT_LIST_HEAD(&dm_thin_pool_table.pools);
|
||
|
}
|
||
|
|
||
|
static void __pool_table_insert(struct pool *pool)
|
||
|
{
|
||
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
|
||
|
list_add(&pool->list, &dm_thin_pool_table.pools);
|
||
|
}
|
||
|
|
||
|
static void __pool_table_remove(struct pool *pool)
|
||
|
{
|
||
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
|
||
|
list_del(&pool->list);
|
||
|
}
|
||
|
|
||
|
static struct pool *__pool_table_lookup(struct mapped_device *md)
|
||
|
{
|
||
|
struct pool *pool = NULL, *tmp;
|
||
|
|
||
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
|
||
|
|
||
|
list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
|
||
|
if (tmp->pool_md == md) {
|
||
|
pool = tmp;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return pool;
|
||
|
}
|
||
|
|
||
|
static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
|
||
|
{
|
||
|
struct pool *pool = NULL, *tmp;
|
||
|
|
||
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
|
||
|
|
||
|
list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
|
||
|
if (tmp->md_dev == md_dev) {
|
||
|
pool = tmp;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return pool;
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------*/
|
||
|
|
||
|
static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master)
|
||
|
{
|
||
|
struct bio *bio;
|
||
|
struct bio_list bios;
|
||
|
|
||
|
bio_list_init(&bios);
|
||
|
bio_list_merge(&bios, master);
|
||
|
bio_list_init(master);
|
||
|
|
||
|
while ((bio = bio_list_pop(&bios))) {
|
||
|
if (dm_get_mapinfo(bio)->ptr == tc)
|
||
|
bio_endio(bio, DM_ENDIO_REQUEUE);
|
||
|
else
|
||
|
bio_list_add(master, bio);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void requeue_io(struct thin_c *tc)
|
||
|
{
|
||
|
struct pool *pool = tc->pool;
|
||
|
unsigned long flags;
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
__requeue_bio_list(tc, &pool->deferred_bios);
|
||
|
__requeue_bio_list(tc, &pool->retry_on_resume_list);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* This section of code contains the logic for processing a thin device's IO.
|
||
|
* Much of the code depends on pool object resources (lists, workqueues, etc)
|
||
|
* but most is exclusively called from the thin target rather than the thin-pool
|
||
|
* target.
|
||
|
*/
|
||
|
|
||
|
static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
|
||
|
{
|
||
|
return bio->bi_sector >> tc->pool->block_shift;
|
||
|
}
|
||
|
|
||
|
static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
|
||
|
{
|
||
|
struct pool *pool = tc->pool;
|
||
|
|
||
|
bio->bi_bdev = tc->pool_dev->bdev;
|
||
|
bio->bi_sector = (block << pool->block_shift) +
|
||
|
(bio->bi_sector & pool->offset_mask);
|
||
|
}
|
||
|
|
||
|
static void remap_and_issue(struct thin_c *tc, struct bio *bio,
|
||
|
dm_block_t block)
|
||
|
{
|
||
|
struct pool *pool = tc->pool;
|
||
|
unsigned long flags;
|
||
|
|
||
|
remap(tc, bio, block);
|
||
|
|
||
|
/*
|
||
|
* Batch together any FUA/FLUSH bios we find and then issue
|
||
|
* a single commit for them in process_deferred_bios().
|
||
|
*/
|
||
|
if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
bio_list_add(&pool->deferred_flush_bios, bio);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
} else
|
||
|
generic_make_request(bio);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* wake_worker() is used when new work is queued and when pool_resume is
|
||
|
* ready to continue deferred IO processing.
|
||
|
*/
|
||
|
static void wake_worker(struct pool *pool)
|
||
|
{
|
||
|
queue_work(pool->wq, &pool->worker);
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------*/
|
||
|
|
||
|
/*
|
||
|
* Bio endio functions.
|
||
|
*/
|
||
|
struct endio_hook {
|
||
|
struct thin_c *tc;
|
||
|
bio_end_io_t *saved_bi_end_io;
|
||
|
struct deferred_entry *entry;
|
||
|
};
|
||
|
|
||
|
struct new_mapping {
|
||
|
struct list_head list;
|
||
|
|
||
|
int prepared;
|
||
|
|
||
|
struct thin_c *tc;
|
||
|
dm_block_t virt_block;
|
||
|
dm_block_t data_block;
|
||
|
struct cell *cell;
|
||
|
int err;
|
||
|
|
||
|
/*
|
||
|
* If the bio covers the whole area of a block then we can avoid
|
||
|
* zeroing or copying. Instead this bio is hooked. The bio will
|
||
|
* still be in the cell, so care has to be taken to avoid issuing
|
||
|
* the bio twice.
|
||
|
*/
|
||
|
struct bio *bio;
|
||
|
bio_end_io_t *saved_bi_end_io;
|
||
|
};
|
||
|
|
||
|
static void __maybe_add_mapping(struct new_mapping *m)
|
||
|
{
|
||
|
struct pool *pool = m->tc->pool;
|
||
|
|
||
|
if (list_empty(&m->list) && m->prepared) {
|
||
|
list_add(&m->list, &pool->prepared_mappings);
|
||
|
wake_worker(pool);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void copy_complete(int read_err, unsigned long write_err, void *context)
|
||
|
{
|
||
|
unsigned long flags;
|
||
|
struct new_mapping *m = context;
|
||
|
struct pool *pool = m->tc->pool;
|
||
|
|
||
|
m->err = read_err || write_err ? -EIO : 0;
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
m->prepared = 1;
|
||
|
__maybe_add_mapping(m);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
}
|
||
|
|
||
|
static void overwrite_endio(struct bio *bio, int err)
|
||
|
{
|
||
|
unsigned long flags;
|
||
|
struct new_mapping *m = dm_get_mapinfo(bio)->ptr;
|
||
|
struct pool *pool = m->tc->pool;
|
||
|
|
||
|
m->err = err;
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
m->prepared = 1;
|
||
|
__maybe_add_mapping(m);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
}
|
||
|
|
||
|
static void shared_read_endio(struct bio *bio, int err)
|
||
|
{
|
||
|
struct list_head mappings;
|
||
|
struct new_mapping *m, *tmp;
|
||
|
struct endio_hook *h = dm_get_mapinfo(bio)->ptr;
|
||
|
unsigned long flags;
|
||
|
struct pool *pool = h->tc->pool;
|
||
|
|
||
|
bio->bi_end_io = h->saved_bi_end_io;
|
||
|
bio_endio(bio, err);
|
||
|
|
||
|
INIT_LIST_HEAD(&mappings);
|
||
|
ds_dec(h->entry, &mappings);
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
list_for_each_entry_safe(m, tmp, &mappings, list) {
|
||
|
list_del(&m->list);
|
||
|
INIT_LIST_HEAD(&m->list);
|
||
|
__maybe_add_mapping(m);
|
||
|
}
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
mempool_free(h, pool->endio_hook_pool);
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------*/
|
||
|
|
||
|
/*
|
||
|
* Workqueue.
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* Prepared mapping jobs.
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* This sends the bios in the cell back to the deferred_bios list.
|
||
|
*/
|
||
|
static void cell_defer(struct thin_c *tc, struct cell *cell,
|
||
|
dm_block_t data_block)
|
||
|
{
|
||
|
struct pool *pool = tc->pool;
|
||
|
unsigned long flags;
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
cell_release(cell, &pool->deferred_bios);
|
||
|
spin_unlock_irqrestore(&tc->pool->lock, flags);
|
||
|
|
||
|
wake_worker(pool);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Same as cell_defer above, except it omits one particular detainee,
|
||
|
* a write bio that covers the block and has already been processed.
|
||
|
*/
|
||
|
static void cell_defer_except(struct thin_c *tc, struct cell *cell,
|
||
|
struct bio *exception)
|
||
|
{
|
||
|
struct bio_list bios;
|
||
|
struct bio *bio;
|
||
|
struct pool *pool = tc->pool;
|
||
|
unsigned long flags;
|
||
|
|
||
|
bio_list_init(&bios);
|
||
|
cell_release(cell, &bios);
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
while ((bio = bio_list_pop(&bios)))
|
||
|
if (bio != exception)
|
||
|
bio_list_add(&pool->deferred_bios, bio);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
wake_worker(pool);
|
||
|
}
|
||
|
|
||
|
static void process_prepared_mapping(struct new_mapping *m)
|
||
|
{
|
||
|
struct thin_c *tc = m->tc;
|
||
|
struct bio *bio;
|
||
|
int r;
|
||
|
|
||
|
bio = m->bio;
|
||
|
if (bio)
|
||
|
bio->bi_end_io = m->saved_bi_end_io;
|
||
|
|
||
|
if (m->err) {
|
||
|
cell_error(m->cell);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Commit the prepared block into the mapping btree.
|
||
|
* Any I/O for this block arriving after this point will get
|
||
|
* remapped to it directly.
|
||
|
*/
|
||
|
r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
|
||
|
if (r) {
|
||
|
DMERR("dm_thin_insert_block() failed");
|
||
|
cell_error(m->cell);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Release any bios held while the block was being provisioned.
|
||
|
* If we are processing a write bio that completely covers the block,
|
||
|
* we already processed it so can ignore it now when processing
|
||
|
* the bios in the cell.
|
||
|
*/
|
||
|
if (bio) {
|
||
|
cell_defer_except(tc, m->cell, bio);
|
||
|
bio_endio(bio, 0);
|
||
|
} else
|
||
|
cell_defer(tc, m->cell, m->data_block);
|
||
|
|
||
|
list_del(&m->list);
|
||
|
mempool_free(m, tc->pool->mapping_pool);
|
||
|
}
|
||
|
|
||
|
static void process_prepared_mappings(struct pool *pool)
|
||
|
{
|
||
|
unsigned long flags;
|
||
|
struct list_head maps;
|
||
|
struct new_mapping *m, *tmp;
|
||
|
|
||
|
INIT_LIST_HEAD(&maps);
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
list_splice_init(&pool->prepared_mappings, &maps);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
list_for_each_entry_safe(m, tmp, &maps, list)
|
||
|
process_prepared_mapping(m);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Deferred bio jobs.
|
||
|
*/
|
||
|
static int io_overwrites_block(struct pool *pool, struct bio *bio)
|
||
|
{
|
||
|
return ((bio_data_dir(bio) == WRITE) &&
|
||
|
!(bio->bi_sector & pool->offset_mask)) &&
|
||
|
(bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT));
|
||
|
}
|
||
|
|
||
|
static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
|
||
|
bio_end_io_t *fn)
|
||
|
{
|
||
|
*save = bio->bi_end_io;
|
||
|
bio->bi_end_io = fn;
|
||
|
}
|
||
|
|
||
|
static int ensure_next_mapping(struct pool *pool)
|
||
|
{
|
||
|
if (pool->next_mapping)
|
||
|
return 0;
|
||
|
|
||
|
pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC);
|
||
|
|
||
|
return pool->next_mapping ? 0 : -ENOMEM;
|
||
|
}
|
||
|
|
||
|
static struct new_mapping *get_next_mapping(struct pool *pool)
|
||
|
{
|
||
|
struct new_mapping *r = pool->next_mapping;
|
||
|
|
||
|
BUG_ON(!pool->next_mapping);
|
||
|
|
||
|
pool->next_mapping = NULL;
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
|
||
|
dm_block_t data_origin, dm_block_t data_dest,
|
||
|
struct cell *cell, struct bio *bio)
|
||
|
{
|
||
|
int r;
|
||
|
struct pool *pool = tc->pool;
|
||
|
struct new_mapping *m = get_next_mapping(pool);
|
||
|
|
||
|
INIT_LIST_HEAD(&m->list);
|
||
|
m->prepared = 0;
|
||
|
m->tc = tc;
|
||
|
m->virt_block = virt_block;
|
||
|
m->data_block = data_dest;
|
||
|
m->cell = cell;
|
||
|
m->err = 0;
|
||
|
m->bio = NULL;
|
||
|
|
||
|
ds_add_work(&pool->ds, &m->list);
|
||
|
|
||
|
/*
|
||
|
* IO to pool_dev remaps to the pool target's data_dev.
|
||
|
*
|
||
|
* If the whole block of data is being overwritten, we can issue the
|
||
|
* bio immediately. Otherwise we use kcopyd to clone the data first.
|
||
|
*/
|
||
|
if (io_overwrites_block(pool, bio)) {
|
||
|
m->bio = bio;
|
||
|
save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
|
||
|
dm_get_mapinfo(bio)->ptr = m;
|
||
|
remap_and_issue(tc, bio, data_dest);
|
||
|
} else {
|
||
|
struct dm_io_region from, to;
|
||
|
|
||
|
from.bdev = tc->pool_dev->bdev;
|
||
|
from.sector = data_origin * pool->sectors_per_block;
|
||
|
from.count = pool->sectors_per_block;
|
||
|
|
||
|
to.bdev = tc->pool_dev->bdev;
|
||
|
to.sector = data_dest * pool->sectors_per_block;
|
||
|
to.count = pool->sectors_per_block;
|
||
|
|
||
|
r = dm_kcopyd_copy(pool->copier, &from, 1, &to,
|
||
|
0, copy_complete, m);
|
||
|
if (r < 0) {
|
||
|
mempool_free(m, pool->mapping_pool);
|
||
|
DMERR("dm_kcopyd_copy() failed");
|
||
|
cell_error(cell);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
|
||
|
dm_block_t data_block, struct cell *cell,
|
||
|
struct bio *bio)
|
||
|
{
|
||
|
struct pool *pool = tc->pool;
|
||
|
struct new_mapping *m = get_next_mapping(pool);
|
||
|
|
||
|
INIT_LIST_HEAD(&m->list);
|
||
|
m->prepared = 0;
|
||
|
m->tc = tc;
|
||
|
m->virt_block = virt_block;
|
||
|
m->data_block = data_block;
|
||
|
m->cell = cell;
|
||
|
m->err = 0;
|
||
|
m->bio = NULL;
|
||
|
|
||
|
/*
|
||
|
* If the whole block of data is being overwritten or we are not
|
||
|
* zeroing pre-existing data, we can issue the bio immediately.
|
||
|
* Otherwise we use kcopyd to zero the data first.
|
||
|
*/
|
||
|
if (!pool->zero_new_blocks)
|
||
|
process_prepared_mapping(m);
|
||
|
|
||
|
else if (io_overwrites_block(pool, bio)) {
|
||
|
m->bio = bio;
|
||
|
save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
|
||
|
dm_get_mapinfo(bio)->ptr = m;
|
||
|
remap_and_issue(tc, bio, data_block);
|
||
|
|
||
|
} else {
|
||
|
int r;
|
||
|
struct dm_io_region to;
|
||
|
|
||
|
to.bdev = tc->pool_dev->bdev;
|
||
|
to.sector = data_block * pool->sectors_per_block;
|
||
|
to.count = pool->sectors_per_block;
|
||
|
|
||
|
r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m);
|
||
|
if (r < 0) {
|
||
|
mempool_free(m, pool->mapping_pool);
|
||
|
DMERR("dm_kcopyd_zero() failed");
|
||
|
cell_error(cell);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
|
||
|
{
|
||
|
int r;
|
||
|
dm_block_t free_blocks;
|
||
|
unsigned long flags;
|
||
|
struct pool *pool = tc->pool;
|
||
|
|
||
|
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
|
||
|
DMWARN("%s: reached low water mark, sending event.",
|
||
|
dm_device_name(pool->pool_md));
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
pool->low_water_triggered = 1;
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
dm_table_event(pool->ti->table);
|
||
|
}
|
||
|
|
||
|
if (!free_blocks) {
|
||
|
if (pool->no_free_space)
|
||
|
return -ENOSPC;
|
||
|
else {
|
||
|
/*
|
||
|
* Try to commit to see if that will free up some
|
||
|
* more space.
|
||
|
*/
|
||
|
r = dm_pool_commit_metadata(pool->pmd);
|
||
|
if (r) {
|
||
|
DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
|
||
|
__func__, r);
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
/*
|
||
|
* If we still have no space we set a flag to avoid
|
||
|
* doing all this checking and return -ENOSPC.
|
||
|
*/
|
||
|
if (!free_blocks) {
|
||
|
DMWARN("%s: no free space available.",
|
||
|
dm_device_name(pool->pool_md));
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
pool->no_free_space = 1;
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
return -ENOSPC;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
r = dm_pool_alloc_data_block(pool->pmd, result);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* If we have run out of space, queue bios until the device is
|
||
|
* resumed, presumably after having been reloaded with more space.
|
||
|
*/
|
||
|
static void retry_on_resume(struct bio *bio)
|
||
|
{
|
||
|
struct thin_c *tc = dm_get_mapinfo(bio)->ptr;
|
||
|
struct pool *pool = tc->pool;
|
||
|
unsigned long flags;
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
bio_list_add(&pool->retry_on_resume_list, bio);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
}
|
||
|
|
||
|
static void no_space(struct cell *cell)
|
||
|
{
|
||
|
struct bio *bio;
|
||
|
struct bio_list bios;
|
||
|
|
||
|
bio_list_init(&bios);
|
||
|
cell_release(cell, &bios);
|
||
|
|
||
|
while ((bio = bio_list_pop(&bios)))
|
||
|
retry_on_resume(bio);
|
||
|
}
|
||
|
|
||
|
static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
|
||
|
struct cell_key *key,
|
||
|
struct dm_thin_lookup_result *lookup_result,
|
||
|
struct cell *cell)
|
||
|
{
|
||
|
int r;
|
||
|
dm_block_t data_block;
|
||
|
|
||
|
r = alloc_data_block(tc, &data_block);
|
||
|
switch (r) {
|
||
|
case 0:
|
||
|
schedule_copy(tc, block, lookup_result->block,
|
||
|
data_block, cell, bio);
|
||
|
break;
|
||
|
|
||
|
case -ENOSPC:
|
||
|
no_space(cell);
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
|
||
|
cell_error(cell);
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void process_shared_bio(struct thin_c *tc, struct bio *bio,
|
||
|
dm_block_t block,
|
||
|
struct dm_thin_lookup_result *lookup_result)
|
||
|
{
|
||
|
struct cell *cell;
|
||
|
struct pool *pool = tc->pool;
|
||
|
struct cell_key key;
|
||
|
|
||
|
/*
|
||
|
* If cell is already occupied, then sharing is already in the process
|
||
|
* of being broken so we have nothing further to do here.
|
||
|
*/
|
||
|
build_data_key(tc->td, lookup_result->block, &key);
|
||
|
if (bio_detain(pool->prison, &key, bio, &cell))
|
||
|
return;
|
||
|
|
||
|
if (bio_data_dir(bio) == WRITE)
|
||
|
break_sharing(tc, bio, block, &key, lookup_result, cell);
|
||
|
else {
|
||
|
struct endio_hook *h;
|
||
|
h = mempool_alloc(pool->endio_hook_pool, GFP_NOIO);
|
||
|
|
||
|
h->tc = tc;
|
||
|
h->entry = ds_inc(&pool->ds);
|
||
|
save_and_set_endio(bio, &h->saved_bi_end_io, shared_read_endio);
|
||
|
dm_get_mapinfo(bio)->ptr = h;
|
||
|
|
||
|
cell_release_singleton(cell, bio);
|
||
|
remap_and_issue(tc, bio, lookup_result->block);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
|
||
|
struct cell *cell)
|
||
|
{
|
||
|
int r;
|
||
|
dm_block_t data_block;
|
||
|
|
||
|
/*
|
||
|
* Remap empty bios (flushes) immediately, without provisioning.
|
||
|
*/
|
||
|
if (!bio->bi_size) {
|
||
|
cell_release_singleton(cell, bio);
|
||
|
remap_and_issue(tc, bio, 0);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Fill read bios with zeroes and complete them immediately.
|
||
|
*/
|
||
|
if (bio_data_dir(bio) == READ) {
|
||
|
zero_fill_bio(bio);
|
||
|
cell_release_singleton(cell, bio);
|
||
|
bio_endio(bio, 0);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
r = alloc_data_block(tc, &data_block);
|
||
|
switch (r) {
|
||
|
case 0:
|
||
|
schedule_zero(tc, block, data_block, cell, bio);
|
||
|
break;
|
||
|
|
||
|
case -ENOSPC:
|
||
|
no_space(cell);
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
|
||
|
cell_error(cell);
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void process_bio(struct thin_c *tc, struct bio *bio)
|
||
|
{
|
||
|
int r;
|
||
|
dm_block_t block = get_bio_block(tc, bio);
|
||
|
struct cell *cell;
|
||
|
struct cell_key key;
|
||
|
struct dm_thin_lookup_result lookup_result;
|
||
|
|
||
|
/*
|
||
|
* If cell is already occupied, then the block is already
|
||
|
* being provisioned so we have nothing further to do here.
|
||
|
*/
|
||
|
build_virtual_key(tc->td, block, &key);
|
||
|
if (bio_detain(tc->pool->prison, &key, bio, &cell))
|
||
|
return;
|
||
|
|
||
|
r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
|
||
|
switch (r) {
|
||
|
case 0:
|
||
|
/*
|
||
|
* We can release this cell now. This thread is the only
|
||
|
* one that puts bios into a cell, and we know there were
|
||
|
* no preceding bios.
|
||
|
*/
|
||
|
/*
|
||
|
* TODO: this will probably have to change when discard goes
|
||
|
* back in.
|
||
|
*/
|
||
|
cell_release_singleton(cell, bio);
|
||
|
|
||
|
if (lookup_result.shared)
|
||
|
process_shared_bio(tc, bio, block, &lookup_result);
|
||
|
else
|
||
|
remap_and_issue(tc, bio, lookup_result.block);
|
||
|
break;
|
||
|
|
||
|
case -ENODATA:
|
||
|
provision_block(tc, bio, block, cell);
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
DMERR("dm_thin_find_block() failed, error = %d", r);
|
||
|
bio_io_error(bio);
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void process_deferred_bios(struct pool *pool)
|
||
|
{
|
||
|
unsigned long flags;
|
||
|
struct bio *bio;
|
||
|
struct bio_list bios;
|
||
|
int r;
|
||
|
|
||
|
bio_list_init(&bios);
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
bio_list_merge(&bios, &pool->deferred_bios);
|
||
|
bio_list_init(&pool->deferred_bios);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
while ((bio = bio_list_pop(&bios))) {
|
||
|
struct thin_c *tc = dm_get_mapinfo(bio)->ptr;
|
||
|
/*
|
||
|
* If we've got no free new_mapping structs, and processing
|
||
|
* this bio might require one, we pause until there are some
|
||
|
* prepared mappings to process.
|
||
|
*/
|
||
|
if (ensure_next_mapping(pool)) {
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
bio_list_merge(&pool->deferred_bios, &bios);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
break;
|
||
|
}
|
||
|
process_bio(tc, bio);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* If there are any deferred flush bios, we must commit
|
||
|
* the metadata before issuing them.
|
||
|
*/
|
||
|
bio_list_init(&bios);
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
bio_list_merge(&bios, &pool->deferred_flush_bios);
|
||
|
bio_list_init(&pool->deferred_flush_bios);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
if (bio_list_empty(&bios))
|
||
|
return;
|
||
|
|
||
|
r = dm_pool_commit_metadata(pool->pmd);
|
||
|
if (r) {
|
||
|
DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
|
||
|
__func__, r);
|
||
|
while ((bio = bio_list_pop(&bios)))
|
||
|
bio_io_error(bio);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
while ((bio = bio_list_pop(&bios)))
|
||
|
generic_make_request(bio);
|
||
|
}
|
||
|
|
||
|
static void do_worker(struct work_struct *ws)
|
||
|
{
|
||
|
struct pool *pool = container_of(ws, struct pool, worker);
|
||
|
|
||
|
process_prepared_mappings(pool);
|
||
|
process_deferred_bios(pool);
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------*/
|
||
|
|
||
|
/*
|
||
|
* Mapping functions.
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* Called only while mapping a thin bio to hand it over to the workqueue.
|
||
|
*/
|
||
|
static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
|
||
|
{
|
||
|
unsigned long flags;
|
||
|
struct pool *pool = tc->pool;
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
bio_list_add(&pool->deferred_bios, bio);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
wake_worker(pool);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Non-blocking function called from the thin target's map function.
|
||
|
*/
|
||
|
static int thin_bio_map(struct dm_target *ti, struct bio *bio,
|
||
|
union map_info *map_context)
|
||
|
{
|
||
|
int r;
|
||
|
struct thin_c *tc = ti->private;
|
||
|
dm_block_t block = get_bio_block(tc, bio);
|
||
|
struct dm_thin_device *td = tc->td;
|
||
|
struct dm_thin_lookup_result result;
|
||
|
|
||
|
/*
|
||
|
* Save the thin context for easy access from the deferred bio later.
|
||
|
*/
|
||
|
map_context->ptr = tc;
|
||
|
|
||
|
if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
|
||
|
thin_defer_bio(tc, bio);
|
||
|
return DM_MAPIO_SUBMITTED;
|
||
|
}
|
||
|
|
||
|
r = dm_thin_find_block(td, block, 0, &result);
|
||
|
|
||
|
/*
|
||
|
* Note that we defer readahead too.
|
||
|
*/
|
||
|
switch (r) {
|
||
|
case 0:
|
||
|
if (unlikely(result.shared)) {
|
||
|
/*
|
||
|
* We have a race condition here between the
|
||
|
* result.shared value returned by the lookup and
|
||
|
* snapshot creation, which may cause new
|
||
|
* sharing.
|
||
|
*
|
||
|
* To avoid this always quiesce the origin before
|
||
|
* taking the snap. You want to do this anyway to
|
||
|
* ensure a consistent application view
|
||
|
* (i.e. lockfs).
|
||
|
*
|
||
|
* More distant ancestors are irrelevant. The
|
||
|
* shared flag will be set in their case.
|
||
|
*/
|
||
|
thin_defer_bio(tc, bio);
|
||
|
r = DM_MAPIO_SUBMITTED;
|
||
|
} else {
|
||
|
remap(tc, bio, result.block);
|
||
|
r = DM_MAPIO_REMAPPED;
|
||
|
}
|
||
|
break;
|
||
|
|
||
|
case -ENODATA:
|
||
|
/*
|
||
|
* In future, the failed dm_thin_find_block above could
|
||
|
* provide the hint to load the metadata into cache.
|
||
|
*/
|
||
|
case -EWOULDBLOCK:
|
||
|
thin_defer_bio(tc, bio);
|
||
|
r = DM_MAPIO_SUBMITTED;
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
|
||
|
{
|
||
|
int r;
|
||
|
unsigned long flags;
|
||
|
struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
|
||
|
|
||
|
spin_lock_irqsave(&pt->pool->lock, flags);
|
||
|
r = !bio_list_empty(&pt->pool->retry_on_resume_list);
|
||
|
spin_unlock_irqrestore(&pt->pool->lock, flags);
|
||
|
|
||
|
if (!r) {
|
||
|
struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
|
||
|
r = bdi_congested(&q->backing_dev_info, bdi_bits);
|
||
|
}
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static void __requeue_bios(struct pool *pool)
|
||
|
{
|
||
|
bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
|
||
|
bio_list_init(&pool->retry_on_resume_list);
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------
|
||
|
* Binding of control targets to a pool object
|
||
|
*--------------------------------------------------------------*/
|
||
|
static int bind_control_target(struct pool *pool, struct dm_target *ti)
|
||
|
{
|
||
|
struct pool_c *pt = ti->private;
|
||
|
|
||
|
pool->ti = ti;
|
||
|
pool->low_water_blocks = pt->low_water_blocks;
|
||
|
pool->zero_new_blocks = pt->zero_new_blocks;
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void unbind_control_target(struct pool *pool, struct dm_target *ti)
|
||
|
{
|
||
|
if (pool->ti == ti)
|
||
|
pool->ti = NULL;
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------
|
||
|
* Pool creation
|
||
|
*--------------------------------------------------------------*/
|
||
|
static void __pool_destroy(struct pool *pool)
|
||
|
{
|
||
|
__pool_table_remove(pool);
|
||
|
|
||
|
if (dm_pool_metadata_close(pool->pmd) < 0)
|
||
|
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
|
||
|
|
||
|
prison_destroy(pool->prison);
|
||
|
dm_kcopyd_client_destroy(pool->copier);
|
||
|
|
||
|
if (pool->wq)
|
||
|
destroy_workqueue(pool->wq);
|
||
|
|
||
|
if (pool->next_mapping)
|
||
|
mempool_free(pool->next_mapping, pool->mapping_pool);
|
||
|
mempool_destroy(pool->mapping_pool);
|
||
|
mempool_destroy(pool->endio_hook_pool);
|
||
|
kfree(pool);
|
||
|
}
|
||
|
|
||
|
static struct pool *pool_create(struct mapped_device *pool_md,
|
||
|
struct block_device *metadata_dev,
|
||
|
unsigned long block_size, char **error)
|
||
|
{
|
||
|
int r;
|
||
|
void *err_p;
|
||
|
struct pool *pool;
|
||
|
struct dm_pool_metadata *pmd;
|
||
|
|
||
|
pmd = dm_pool_metadata_open(metadata_dev, block_size);
|
||
|
if (IS_ERR(pmd)) {
|
||
|
*error = "Error creating metadata object";
|
||
|
return (struct pool *)pmd;
|
||
|
}
|
||
|
|
||
|
pool = kmalloc(sizeof(*pool), GFP_KERNEL);
|
||
|
if (!pool) {
|
||
|
*error = "Error allocating memory for pool";
|
||
|
err_p = ERR_PTR(-ENOMEM);
|
||
|
goto bad_pool;
|
||
|
}
|
||
|
|
||
|
pool->pmd = pmd;
|
||
|
pool->sectors_per_block = block_size;
|
||
|
pool->block_shift = ffs(block_size) - 1;
|
||
|
pool->offset_mask = block_size - 1;
|
||
|
pool->low_water_blocks = 0;
|
||
|
pool->zero_new_blocks = 1;
|
||
|
pool->prison = prison_create(PRISON_CELLS);
|
||
|
if (!pool->prison) {
|
||
|
*error = "Error creating pool's bio prison";
|
||
|
err_p = ERR_PTR(-ENOMEM);
|
||
|
goto bad_prison;
|
||
|
}
|
||
|
|
||
|
pool->copier = dm_kcopyd_client_create();
|
||
|
if (IS_ERR(pool->copier)) {
|
||
|
r = PTR_ERR(pool->copier);
|
||
|
*error = "Error creating pool's kcopyd client";
|
||
|
err_p = ERR_PTR(r);
|
||
|
goto bad_kcopyd_client;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Create singlethreaded workqueue that will service all devices
|
||
|
* that use this metadata.
|
||
|
*/
|
||
|
pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
|
||
|
if (!pool->wq) {
|
||
|
*error = "Error creating pool's workqueue";
|
||
|
err_p = ERR_PTR(-ENOMEM);
|
||
|
goto bad_wq;
|
||
|
}
|
||
|
|
||
|
INIT_WORK(&pool->worker, do_worker);
|
||
|
spin_lock_init(&pool->lock);
|
||
|
bio_list_init(&pool->deferred_bios);
|
||
|
bio_list_init(&pool->deferred_flush_bios);
|
||
|
INIT_LIST_HEAD(&pool->prepared_mappings);
|
||
|
pool->low_water_triggered = 0;
|
||
|
pool->no_free_space = 0;
|
||
|
bio_list_init(&pool->retry_on_resume_list);
|
||
|
ds_init(&pool->ds);
|
||
|
|
||
|
pool->next_mapping = NULL;
|
||
|
pool->mapping_pool =
|
||
|
mempool_create_kmalloc_pool(MAPPING_POOL_SIZE, sizeof(struct new_mapping));
|
||
|
if (!pool->mapping_pool) {
|
||
|
*error = "Error creating pool's mapping mempool";
|
||
|
err_p = ERR_PTR(-ENOMEM);
|
||
|
goto bad_mapping_pool;
|
||
|
}
|
||
|
|
||
|
pool->endio_hook_pool =
|
||
|
mempool_create_kmalloc_pool(ENDIO_HOOK_POOL_SIZE, sizeof(struct endio_hook));
|
||
|
if (!pool->endio_hook_pool) {
|
||
|
*error = "Error creating pool's endio_hook mempool";
|
||
|
err_p = ERR_PTR(-ENOMEM);
|
||
|
goto bad_endio_hook_pool;
|
||
|
}
|
||
|
pool->ref_count = 1;
|
||
|
pool->pool_md = pool_md;
|
||
|
pool->md_dev = metadata_dev;
|
||
|
__pool_table_insert(pool);
|
||
|
|
||
|
return pool;
|
||
|
|
||
|
bad_endio_hook_pool:
|
||
|
mempool_destroy(pool->mapping_pool);
|
||
|
bad_mapping_pool:
|
||
|
destroy_workqueue(pool->wq);
|
||
|
bad_wq:
|
||
|
dm_kcopyd_client_destroy(pool->copier);
|
||
|
bad_kcopyd_client:
|
||
|
prison_destroy(pool->prison);
|
||
|
bad_prison:
|
||
|
kfree(pool);
|
||
|
bad_pool:
|
||
|
if (dm_pool_metadata_close(pmd))
|
||
|
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
|
||
|
|
||
|
return err_p;
|
||
|
}
|
||
|
|
||
|
static void __pool_inc(struct pool *pool)
|
||
|
{
|
||
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
|
||
|
pool->ref_count++;
|
||
|
}
|
||
|
|
||
|
static void __pool_dec(struct pool *pool)
|
||
|
{
|
||
|
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
|
||
|
BUG_ON(!pool->ref_count);
|
||
|
if (!--pool->ref_count)
|
||
|
__pool_destroy(pool);
|
||
|
}
|
||
|
|
||
|
static struct pool *__pool_find(struct mapped_device *pool_md,
|
||
|
struct block_device *metadata_dev,
|
||
|
unsigned long block_size, char **error)
|
||
|
{
|
||
|
struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
|
||
|
|
||
|
if (pool) {
|
||
|
if (pool->pool_md != pool_md)
|
||
|
return ERR_PTR(-EBUSY);
|
||
|
__pool_inc(pool);
|
||
|
|
||
|
} else {
|
||
|
pool = __pool_table_lookup(pool_md);
|
||
|
if (pool) {
|
||
|
if (pool->md_dev != metadata_dev)
|
||
|
return ERR_PTR(-EINVAL);
|
||
|
__pool_inc(pool);
|
||
|
|
||
|
} else
|
||
|
pool = pool_create(pool_md, metadata_dev, block_size, error);
|
||
|
}
|
||
|
|
||
|
return pool;
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------
|
||
|
* Pool target methods
|
||
|
*--------------------------------------------------------------*/
|
||
|
static void pool_dtr(struct dm_target *ti)
|
||
|
{
|
||
|
struct pool_c *pt = ti->private;
|
||
|
|
||
|
mutex_lock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
unbind_control_target(pt->pool, ti);
|
||
|
__pool_dec(pt->pool);
|
||
|
dm_put_device(ti, pt->metadata_dev);
|
||
|
dm_put_device(ti, pt->data_dev);
|
||
|
kfree(pt);
|
||
|
|
||
|
mutex_unlock(&dm_thin_pool_table.mutex);
|
||
|
}
|
||
|
|
||
|
struct pool_features {
|
||
|
unsigned zero_new_blocks:1;
|
||
|
};
|
||
|
|
||
|
static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
|
||
|
struct dm_target *ti)
|
||
|
{
|
||
|
int r;
|
||
|
unsigned argc;
|
||
|
const char *arg_name;
|
||
|
|
||
|
static struct dm_arg _args[] = {
|
||
|
{0, 1, "Invalid number of pool feature arguments"},
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* No feature arguments supplied.
|
||
|
*/
|
||
|
if (!as->argc)
|
||
|
return 0;
|
||
|
|
||
|
r = dm_read_arg_group(_args, as, &argc, &ti->error);
|
||
|
if (r)
|
||
|
return -EINVAL;
|
||
|
|
||
|
while (argc && !r) {
|
||
|
arg_name = dm_shift_arg(as);
|
||
|
argc--;
|
||
|
|
||
|
if (!strcasecmp(arg_name, "skip_block_zeroing")) {
|
||
|
pf->zero_new_blocks = 0;
|
||
|
continue;
|
||
|
}
|
||
|
|
||
|
ti->error = "Unrecognised pool feature requested";
|
||
|
r = -EINVAL;
|
||
|
}
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* thin-pool <metadata dev> <data dev>
|
||
|
* <data block size (sectors)>
|
||
|
* <low water mark (blocks)>
|
||
|
* [<#feature args> [<arg>]*]
|
||
|
*
|
||
|
* Optional feature arguments are:
|
||
|
* skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
|
||
|
*/
|
||
|
static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv)
|
||
|
{
|
||
|
int r;
|
||
|
struct pool_c *pt;
|
||
|
struct pool *pool;
|
||
|
struct pool_features pf;
|
||
|
struct dm_arg_set as;
|
||
|
struct dm_dev *data_dev;
|
||
|
unsigned long block_size;
|
||
|
dm_block_t low_water_blocks;
|
||
|
struct dm_dev *metadata_dev;
|
||
|
sector_t metadata_dev_size;
|
||
|
|
||
|
/*
|
||
|
* FIXME Remove validation from scope of lock.
|
||
|
*/
|
||
|
mutex_lock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
if (argc < 4) {
|
||
|
ti->error = "Invalid argument count";
|
||
|
r = -EINVAL;
|
||
|
goto out_unlock;
|
||
|
}
|
||
|
as.argc = argc;
|
||
|
as.argv = argv;
|
||
|
|
||
|
r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev);
|
||
|
if (r) {
|
||
|
ti->error = "Error opening metadata block device";
|
||
|
goto out_unlock;
|
||
|
}
|
||
|
|
||
|
metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT;
|
||
|
if (metadata_dev_size > METADATA_DEV_MAX_SECTORS) {
|
||
|
ti->error = "Metadata device is too large";
|
||
|
r = -EINVAL;
|
||
|
goto out_metadata;
|
||
|
}
|
||
|
|
||
|
r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev);
|
||
|
if (r) {
|
||
|
ti->error = "Error getting data device";
|
||
|
goto out_metadata;
|
||
|
}
|
||
|
|
||
|
if (kstrtoul(argv[2], 10, &block_size) || !block_size ||
|
||
|
block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
|
||
|
block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
|
||
|
!is_power_of_2(block_size)) {
|
||
|
ti->error = "Invalid block size";
|
||
|
r = -EINVAL;
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) {
|
||
|
ti->error = "Invalid low water mark";
|
||
|
r = -EINVAL;
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Set default pool features.
|
||
|
*/
|
||
|
memset(&pf, 0, sizeof(pf));
|
||
|
pf.zero_new_blocks = 1;
|
||
|
|
||
|
dm_consume_args(&as, 4);
|
||
|
r = parse_pool_features(&as, &pf, ti);
|
||
|
if (r)
|
||
|
goto out;
|
||
|
|
||
|
pt = kzalloc(sizeof(*pt), GFP_KERNEL);
|
||
|
if (!pt) {
|
||
|
r = -ENOMEM;
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev,
|
||
|
block_size, &ti->error);
|
||
|
if (IS_ERR(pool)) {
|
||
|
r = PTR_ERR(pool);
|
||
|
goto out_free_pt;
|
||
|
}
|
||
|
|
||
|
pt->pool = pool;
|
||
|
pt->ti = ti;
|
||
|
pt->metadata_dev = metadata_dev;
|
||
|
pt->data_dev = data_dev;
|
||
|
pt->low_water_blocks = low_water_blocks;
|
||
|
pt->zero_new_blocks = pf.zero_new_blocks;
|
||
|
ti->num_flush_requests = 1;
|
||
|
ti->num_discard_requests = 0;
|
||
|
ti->private = pt;
|
||
|
|
||
|
pt->callbacks.congested_fn = pool_is_congested;
|
||
|
dm_table_add_target_callbacks(ti->table, &pt->callbacks);
|
||
|
|
||
|
mutex_unlock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
out_free_pt:
|
||
|
kfree(pt);
|
||
|
out:
|
||
|
dm_put_device(ti, data_dev);
|
||
|
out_metadata:
|
||
|
dm_put_device(ti, metadata_dev);
|
||
|
out_unlock:
|
||
|
mutex_unlock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static int pool_map(struct dm_target *ti, struct bio *bio,
|
||
|
union map_info *map_context)
|
||
|
{
|
||
|
int r;
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct pool *pool = pt->pool;
|
||
|
unsigned long flags;
|
||
|
|
||
|
/*
|
||
|
* As this is a singleton target, ti->begin is always zero.
|
||
|
*/
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
bio->bi_bdev = pt->data_dev->bdev;
|
||
|
r = DM_MAPIO_REMAPPED;
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Retrieves the number of blocks of the data device from
|
||
|
* the superblock and compares it to the actual device size,
|
||
|
* thus resizing the data device in case it has grown.
|
||
|
*
|
||
|
* This both copes with opening preallocated data devices in the ctr
|
||
|
* being followed by a resume
|
||
|
* -and-
|
||
|
* calling the resume method individually after userspace has
|
||
|
* grown the data device in reaction to a table event.
|
||
|
*/
|
||
|
static int pool_preresume(struct dm_target *ti)
|
||
|
{
|
||
|
int r;
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct pool *pool = pt->pool;
|
||
|
dm_block_t data_size, sb_data_size;
|
||
|
|
||
|
/*
|
||
|
* Take control of the pool object.
|
||
|
*/
|
||
|
r = bind_control_target(pool, ti);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
data_size = ti->len >> pool->block_shift;
|
||
|
r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
|
||
|
if (r) {
|
||
|
DMERR("failed to retrieve data device size");
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
if (data_size < sb_data_size) {
|
||
|
DMERR("pool target too small, is %llu blocks (expected %llu)",
|
||
|
data_size, sb_data_size);
|
||
|
return -EINVAL;
|
||
|
|
||
|
} else if (data_size > sb_data_size) {
|
||
|
r = dm_pool_resize_data_dev(pool->pmd, data_size);
|
||
|
if (r) {
|
||
|
DMERR("failed to resize data device");
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
r = dm_pool_commit_metadata(pool->pmd);
|
||
|
if (r) {
|
||
|
DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
|
||
|
__func__, r);
|
||
|
return r;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void pool_resume(struct dm_target *ti)
|
||
|
{
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct pool *pool = pt->pool;
|
||
|
unsigned long flags;
|
||
|
|
||
|
spin_lock_irqsave(&pool->lock, flags);
|
||
|
pool->low_water_triggered = 0;
|
||
|
pool->no_free_space = 0;
|
||
|
__requeue_bios(pool);
|
||
|
spin_unlock_irqrestore(&pool->lock, flags);
|
||
|
|
||
|
wake_worker(pool);
|
||
|
}
|
||
|
|
||
|
static void pool_postsuspend(struct dm_target *ti)
|
||
|
{
|
||
|
int r;
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct pool *pool = pt->pool;
|
||
|
|
||
|
flush_workqueue(pool->wq);
|
||
|
|
||
|
r = dm_pool_commit_metadata(pool->pmd);
|
||
|
if (r < 0) {
|
||
|
DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
|
||
|
__func__, r);
|
||
|
/* FIXME: invalidate device? error the next FUA or FLUSH bio ?*/
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static int check_arg_count(unsigned argc, unsigned args_required)
|
||
|
{
|
||
|
if (argc != args_required) {
|
||
|
DMWARN("Message received with %u arguments instead of %u.",
|
||
|
argc, args_required);
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning)
|
||
|
{
|
||
|
if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) &&
|
||
|
*dev_id <= MAX_DEV_ID)
|
||
|
return 0;
|
||
|
|
||
|
if (warning)
|
||
|
DMWARN("Message received with invalid device id: %s", arg);
|
||
|
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool)
|
||
|
{
|
||
|
dm_thin_id dev_id;
|
||
|
int r;
|
||
|
|
||
|
r = check_arg_count(argc, 2);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = read_dev_id(argv[1], &dev_id, 1);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_create_thin(pool->pmd, dev_id);
|
||
|
if (r) {
|
||
|
DMWARN("Creation of new thinly-provisioned device with id %s failed.",
|
||
|
argv[1]);
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool)
|
||
|
{
|
||
|
dm_thin_id dev_id;
|
||
|
dm_thin_id origin_dev_id;
|
||
|
int r;
|
||
|
|
||
|
r = check_arg_count(argc, 3);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = read_dev_id(argv[1], &dev_id, 1);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = read_dev_id(argv[2], &origin_dev_id, 1);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id);
|
||
|
if (r) {
|
||
|
DMWARN("Creation of new snapshot %s of device %s failed.",
|
||
|
argv[1], argv[2]);
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool)
|
||
|
{
|
||
|
dm_thin_id dev_id;
|
||
|
int r;
|
||
|
|
||
|
r = check_arg_count(argc, 2);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = read_dev_id(argv[1], &dev_id, 1);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_delete_thin_device(pool->pmd, dev_id);
|
||
|
if (r)
|
||
|
DMWARN("Deletion of thin device %s failed.", argv[1]);
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool)
|
||
|
{
|
||
|
dm_thin_id old_id, new_id;
|
||
|
int r;
|
||
|
|
||
|
r = check_arg_count(argc, 3);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) {
|
||
|
DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]);
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) {
|
||
|
DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]);
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id);
|
||
|
if (r) {
|
||
|
DMWARN("Failed to change transaction id from %s to %s.",
|
||
|
argv[1], argv[2]);
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Messages supported:
|
||
|
* create_thin <dev_id>
|
||
|
* create_snap <dev_id> <origin_id>
|
||
|
* delete <dev_id>
|
||
|
* trim <dev_id> <new_size_in_sectors>
|
||
|
* set_transaction_id <current_trans_id> <new_trans_id>
|
||
|
*/
|
||
|
static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
|
||
|
{
|
||
|
int r = -EINVAL;
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct pool *pool = pt->pool;
|
||
|
|
||
|
if (!strcasecmp(argv[0], "create_thin"))
|
||
|
r = process_create_thin_mesg(argc, argv, pool);
|
||
|
|
||
|
else if (!strcasecmp(argv[0], "create_snap"))
|
||
|
r = process_create_snap_mesg(argc, argv, pool);
|
||
|
|
||
|
else if (!strcasecmp(argv[0], "delete"))
|
||
|
r = process_delete_mesg(argc, argv, pool);
|
||
|
|
||
|
else if (!strcasecmp(argv[0], "set_transaction_id"))
|
||
|
r = process_set_transaction_id_mesg(argc, argv, pool);
|
||
|
|
||
|
else
|
||
|
DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
|
||
|
|
||
|
if (!r) {
|
||
|
r = dm_pool_commit_metadata(pool->pmd);
|
||
|
if (r)
|
||
|
DMERR("%s message: dm_pool_commit_metadata() failed, error = %d",
|
||
|
argv[0], r);
|
||
|
}
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Status line is:
|
||
|
* <transaction id> <used metadata sectors>/<total metadata sectors>
|
||
|
* <used data sectors>/<total data sectors> <held metadata root>
|
||
|
*/
|
||
|
static int pool_status(struct dm_target *ti, status_type_t type,
|
||
|
char *result, unsigned maxlen)
|
||
|
{
|
||
|
int r;
|
||
|
unsigned sz = 0;
|
||
|
uint64_t transaction_id;
|
||
|
dm_block_t nr_free_blocks_data;
|
||
|
dm_block_t nr_free_blocks_metadata;
|
||
|
dm_block_t nr_blocks_data;
|
||
|
dm_block_t nr_blocks_metadata;
|
||
|
dm_block_t held_root;
|
||
|
char buf[BDEVNAME_SIZE];
|
||
|
char buf2[BDEVNAME_SIZE];
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct pool *pool = pt->pool;
|
||
|
|
||
|
switch (type) {
|
||
|
case STATUSTYPE_INFO:
|
||
|
r = dm_pool_get_metadata_transaction_id(pool->pmd,
|
||
|
&transaction_id);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_get_free_metadata_block_count(pool->pmd,
|
||
|
&nr_free_blocks_metadata);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_get_free_block_count(pool->pmd,
|
||
|
&nr_free_blocks_data);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_pool_get_held_metadata_root(pool->pmd, &held_root);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
DMEMIT("%llu %llu/%llu %llu/%llu ",
|
||
|
(unsigned long long)transaction_id,
|
||
|
(unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
|
||
|
(unsigned long long)nr_blocks_metadata,
|
||
|
(unsigned long long)(nr_blocks_data - nr_free_blocks_data),
|
||
|
(unsigned long long)nr_blocks_data);
|
||
|
|
||
|
if (held_root)
|
||
|
DMEMIT("%llu", held_root);
|
||
|
else
|
||
|
DMEMIT("-");
|
||
|
|
||
|
break;
|
||
|
|
||
|
case STATUSTYPE_TABLE:
|
||
|
DMEMIT("%s %s %lu %llu ",
|
||
|
format_dev_t(buf, pt->metadata_dev->bdev->bd_dev),
|
||
|
format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
|
||
|
(unsigned long)pool->sectors_per_block,
|
||
|
(unsigned long long)pt->low_water_blocks);
|
||
|
|
||
|
DMEMIT("%u ", !pool->zero_new_blocks);
|
||
|
|
||
|
if (!pool->zero_new_blocks)
|
||
|
DMEMIT("skip_block_zeroing ");
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int pool_iterate_devices(struct dm_target *ti,
|
||
|
iterate_devices_callout_fn fn, void *data)
|
||
|
{
|
||
|
struct pool_c *pt = ti->private;
|
||
|
|
||
|
return fn(ti, pt->data_dev, 0, ti->len, data);
|
||
|
}
|
||
|
|
||
|
static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
|
||
|
struct bio_vec *biovec, int max_size)
|
||
|
{
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
|
||
|
|
||
|
if (!q->merge_bvec_fn)
|
||
|
return max_size;
|
||
|
|
||
|
bvm->bi_bdev = pt->data_dev->bdev;
|
||
|
|
||
|
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
|
||
|
}
|
||
|
|
||
|
static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
|
||
|
{
|
||
|
struct pool_c *pt = ti->private;
|
||
|
struct pool *pool = pt->pool;
|
||
|
|
||
|
blk_limits_io_min(limits, 0);
|
||
|
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
|
||
|
}
|
||
|
|
||
|
static struct target_type pool_target = {
|
||
|
.name = "thin-pool",
|
||
|
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
|
||
|
DM_TARGET_IMMUTABLE,
|
||
|
.version = {1, 0, 0},
|
||
|
.module = THIS_MODULE,
|
||
|
.ctr = pool_ctr,
|
||
|
.dtr = pool_dtr,
|
||
|
.map = pool_map,
|
||
|
.postsuspend = pool_postsuspend,
|
||
|
.preresume = pool_preresume,
|
||
|
.resume = pool_resume,
|
||
|
.message = pool_message,
|
||
|
.status = pool_status,
|
||
|
.merge = pool_merge,
|
||
|
.iterate_devices = pool_iterate_devices,
|
||
|
.io_hints = pool_io_hints,
|
||
|
};
|
||
|
|
||
|
/*----------------------------------------------------------------
|
||
|
* Thin target methods
|
||
|
*--------------------------------------------------------------*/
|
||
|
static void thin_dtr(struct dm_target *ti)
|
||
|
{
|
||
|
struct thin_c *tc = ti->private;
|
||
|
|
||
|
mutex_lock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
__pool_dec(tc->pool);
|
||
|
dm_pool_close_thin_device(tc->td);
|
||
|
dm_put_device(ti, tc->pool_dev);
|
||
|
kfree(tc);
|
||
|
|
||
|
mutex_unlock(&dm_thin_pool_table.mutex);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Thin target parameters:
|
||
|
*
|
||
|
* <pool_dev> <dev_id>
|
||
|
*
|
||
|
* pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
|
||
|
* dev_id: the internal device identifier
|
||
|
*/
|
||
|
static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
|
||
|
{
|
||
|
int r;
|
||
|
struct thin_c *tc;
|
||
|
struct dm_dev *pool_dev;
|
||
|
struct mapped_device *pool_md;
|
||
|
|
||
|
mutex_lock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
if (argc != 2) {
|
||
|
ti->error = "Invalid argument count";
|
||
|
r = -EINVAL;
|
||
|
goto out_unlock;
|
||
|
}
|
||
|
|
||
|
tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL);
|
||
|
if (!tc) {
|
||
|
ti->error = "Out of memory";
|
||
|
r = -ENOMEM;
|
||
|
goto out_unlock;
|
||
|
}
|
||
|
|
||
|
r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);
|
||
|
if (r) {
|
||
|
ti->error = "Error opening pool device";
|
||
|
goto bad_pool_dev;
|
||
|
}
|
||
|
tc->pool_dev = pool_dev;
|
||
|
|
||
|
if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) {
|
||
|
ti->error = "Invalid device id";
|
||
|
r = -EINVAL;
|
||
|
goto bad_common;
|
||
|
}
|
||
|
|
||
|
pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev);
|
||
|
if (!pool_md) {
|
||
|
ti->error = "Couldn't get pool mapped device";
|
||
|
r = -EINVAL;
|
||
|
goto bad_common;
|
||
|
}
|
||
|
|
||
|
tc->pool = __pool_table_lookup(pool_md);
|
||
|
if (!tc->pool) {
|
||
|
ti->error = "Couldn't find pool object";
|
||
|
r = -EINVAL;
|
||
|
goto bad_pool_lookup;
|
||
|
}
|
||
|
__pool_inc(tc->pool);
|
||
|
|
||
|
r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
|
||
|
if (r) {
|
||
|
ti->error = "Couldn't open thin internal device";
|
||
|
goto bad_thin_open;
|
||
|
}
|
||
|
|
||
|
ti->split_io = tc->pool->sectors_per_block;
|
||
|
ti->num_flush_requests = 1;
|
||
|
ti->num_discard_requests = 0;
|
||
|
ti->discards_supported = 0;
|
||
|
|
||
|
dm_put(pool_md);
|
||
|
|
||
|
mutex_unlock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
bad_thin_open:
|
||
|
__pool_dec(tc->pool);
|
||
|
bad_pool_lookup:
|
||
|
dm_put(pool_md);
|
||
|
bad_common:
|
||
|
dm_put_device(ti, tc->pool_dev);
|
||
|
bad_pool_dev:
|
||
|
kfree(tc);
|
||
|
out_unlock:
|
||
|
mutex_unlock(&dm_thin_pool_table.mutex);
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static int thin_map(struct dm_target *ti, struct bio *bio,
|
||
|
union map_info *map_context)
|
||
|
{
|
||
|
bio->bi_sector -= ti->begin;
|
||
|
|
||
|
return thin_bio_map(ti, bio, map_context);
|
||
|
}
|
||
|
|
||
|
static void thin_postsuspend(struct dm_target *ti)
|
||
|
{
|
||
|
if (dm_noflush_suspending(ti))
|
||
|
requeue_io((struct thin_c *)ti->private);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* <nr mapped sectors> <highest mapped sector>
|
||
|
*/
|
||
|
static int thin_status(struct dm_target *ti, status_type_t type,
|
||
|
char *result, unsigned maxlen)
|
||
|
{
|
||
|
int r;
|
||
|
ssize_t sz = 0;
|
||
|
dm_block_t mapped, highest;
|
||
|
char buf[BDEVNAME_SIZE];
|
||
|
struct thin_c *tc = ti->private;
|
||
|
|
||
|
if (!tc->td)
|
||
|
DMEMIT("-");
|
||
|
else {
|
||
|
switch (type) {
|
||
|
case STATUSTYPE_INFO:
|
||
|
r = dm_thin_get_mapped_count(tc->td, &mapped);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_thin_get_highest_mapped_block(tc->td, &highest);
|
||
|
if (r < 0)
|
||
|
return r;
|
||
|
|
||
|
DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
|
||
|
if (r)
|
||
|
DMEMIT("%llu", ((highest + 1) *
|
||
|
tc->pool->sectors_per_block) - 1);
|
||
|
else
|
||
|
DMEMIT("-");
|
||
|
break;
|
||
|
|
||
|
case STATUSTYPE_TABLE:
|
||
|
DMEMIT("%s %lu",
|
||
|
format_dev_t(buf, tc->pool_dev->bdev->bd_dev),
|
||
|
(unsigned long) tc->dev_id);
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int thin_iterate_devices(struct dm_target *ti,
|
||
|
iterate_devices_callout_fn fn, void *data)
|
||
|
{
|
||
|
dm_block_t blocks;
|
||
|
struct thin_c *tc = ti->private;
|
||
|
|
||
|
/*
|
||
|
* We can't call dm_pool_get_data_dev_size() since that blocks. So
|
||
|
* we follow a more convoluted path through to the pool's target.
|
||
|
*/
|
||
|
if (!tc->pool->ti)
|
||
|
return 0; /* nothing is bound */
|
||
|
|
||
|
blocks = tc->pool->ti->len >> tc->pool->block_shift;
|
||
|
if (blocks)
|
||
|
return fn(ti, tc->pool_dev, 0, tc->pool->sectors_per_block * blocks, data);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
|
||
|
{
|
||
|
struct thin_c *tc = ti->private;
|
||
|
|
||
|
blk_limits_io_min(limits, 0);
|
||
|
blk_limits_io_opt(limits, tc->pool->sectors_per_block << SECTOR_SHIFT);
|
||
|
}
|
||
|
|
||
|
static struct target_type thin_target = {
|
||
|
.name = "thin",
|
||
|
.version = {1, 0, 0},
|
||
|
.module = THIS_MODULE,
|
||
|
.ctr = thin_ctr,
|
||
|
.dtr = thin_dtr,
|
||
|
.map = thin_map,
|
||
|
.postsuspend = thin_postsuspend,
|
||
|
.status = thin_status,
|
||
|
.iterate_devices = thin_iterate_devices,
|
||
|
.io_hints = thin_io_hints,
|
||
|
};
|
||
|
|
||
|
/*----------------------------------------------------------------*/
|
||
|
|
||
|
static int __init dm_thin_init(void)
|
||
|
{
|
||
|
int r;
|
||
|
|
||
|
pool_table_init();
|
||
|
|
||
|
r = dm_register_target(&thin_target);
|
||
|
if (r)
|
||
|
return r;
|
||
|
|
||
|
r = dm_register_target(&pool_target);
|
||
|
if (r)
|
||
|
dm_unregister_target(&thin_target);
|
||
|
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static void dm_thin_exit(void)
|
||
|
{
|
||
|
dm_unregister_target(&thin_target);
|
||
|
dm_unregister_target(&pool_target);
|
||
|
}
|
||
|
|
||
|
module_init(dm_thin_init);
|
||
|
module_exit(dm_thin_exit);
|
||
|
|
||
|
MODULE_DESCRIPTION(DM_NAME "device-mapper thin provisioning target");
|
||
|
MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
|
||
|
MODULE_LICENSE("GPL");
|