From: Martin K. Petersen This patch provides support for data integrity passthrough in the device mapper. - If one or more component devices support integrity an integrity profile is preallocated for the DM device. [FIXME: Looks as if that will hit BUG_ON(template == NULL) - maybe there's an undocumented dependency on some other patch? Does this handle table swaps correctly? i.e. NULL must leave any existing (live) setting unchanged.] - If all component devices have compatible profiles the DM device is flagged as capable. - Handle integrity metadata when splitting and cloning bios. [FIXME: Does this cope with integrity profile needing removing after a table swap?] [FIXME: blk_integrity_register() allocating & manipulating kobjects needs moving outside __bind(). - Does the preallocation address this now, with the exception of some unimportant races we'll ignore but should document? E.g. What happens if integrity profile appears on an underlying device between the reload and the table swap. Would it be better for the table swap to fail in that particular case?] Signed-off-by: Martin K. Petersen --- drivers/md/dm-ioctl.c | 21 +++++++++++++++++++++ drivers/md/dm-table.c | 39 +++++++++++++++++++++++++++++++++++++++ drivers/md/dm.c | 15 +++++++++++++++ 3 files changed, 75 insertions(+) Index: linux-2.6.28/drivers/md/dm-ioctl.c =================================================================== --- linux-2.6.28.orig/drivers/md/dm-ioctl.c 2009-01-06 21:36:12.000000000 +0000 +++ linux-2.6.28/drivers/md/dm-ioctl.c 2009-01-07 18:34:15.000000000 +0000 @@ -1047,6 +1047,19 @@ static int populate_table(struct dm_tabl return dm_table_complete(table); } +static int table_prealloc_integrity(struct dm_table *t, + struct mapped_device *md) +{ + struct list_head *devices = dm_table_get_devices(t); + struct dm_dev_internal *dd; + + list_for_each_entry(dd, devices, list) + if (bdev_get_integrity(dd->dm_dev.bdev)) + return blk_integrity_register(dm_disk(md), NULL); + + return 0; +} + static int table_load(struct dm_ioctl *param, size_t param_size) { int r; @@ -1068,6 +1081,14 @@ static int table_load(struct dm_ioctl *p goto out; } + r = table_prealloc_integrity(t, md); + if (r) { + DMERR("%s: could not register integrity profile.", + dm_device_name(md)); + dm_table_destroy(t); + goto out; + } + down_write(&_hash_lock); hc = dm_get_mdptr(md); if (!hc || hc->md != md) { Index: linux-2.6.28/drivers/md/dm-table.c =================================================================== --- linux-2.6.28.orig/drivers/md/dm-table.c 2009-01-07 15:38:20.000000000 +0000 +++ linux-2.6.28/drivers/md/dm-table.c 2009-01-07 18:56:59.000000000 +0000 @@ -877,6 +877,44 @@ struct dm_target *dm_table_find_target(s return &t->targets[(KEYS_PER_NODE * n) + k]; } +/* + * Set the integrity profile for this device if all devices used have + * matching profiles. + */ +static void dm_table_set_integrity(struct dm_table *t) +{ + struct list_head *devices = dm_table_get_devices(t); + struct dm_dev_internal *prev = NULL, *dd = NULL; + struct blk_integrity *bi; + + list_for_each_entry(dd, devices, list) { + if (prev && + blk_integrity_compare(prev->dm_dev.bdev->bd_disk, + dd->dm_dev.bdev->bd_disk) < 0) { + DMWARN("%s: integrity not set: %s and %s mismatch", + dm_device_name(t->md), + prev->dm_dev.bdev->bd_disk->disk_name, + dd->dm_dev.bdev->bd_disk->disk_name); + return; + } + prev = dd; + } + + if (!prev) + return; + + bi = bdev_get_integrity(prev->dm_dev.bdev); + if (!bi) + return; + + /* Register dm device as being integrity capable */ + if (blk_integrity_register(dm_disk(t->md), bi)) + DMERR("%s: %s: blk_integrity_register failed.", + __func__, dm_device_name(t->md)); + else + DMDEBUG("%s: Enabling data integrity.", dm_device_name(t->md)); +} + void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) { /* @@ -897,6 +935,7 @@ void dm_table_set_restrictions(struct dm else queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); + dm_table_set_integrity(t); } unsigned int dm_table_get_num_targets(struct dm_table *t) Index: linux-2.6.28/drivers/md/dm.c =================================================================== --- linux-2.6.28.orig/drivers/md/dm.c 2009-01-07 15:38:20.000000000 +0000 +++ linux-2.6.28/drivers/md/dm.c 2009-01-07 18:43:17.000000000 +0000 @@ -703,6 +703,12 @@ static struct bio *split_bvec(struct bio clone->bi_io_vec->bv_len = clone->bi_size; clone->bi_flags |= 1 << BIO_CLONED; + if (bio_integrity(bio)) { + bio_integrity_clone(clone, bio, bs); + bio_integrity_trim(clone, + bio_sector_offset(bio, idx, offset), len); + } + return clone; } @@ -724,6 +730,14 @@ static struct bio *clone_bio(struct bio clone->bi_size = to_bytes(len); clone->bi_flags &= ~(1 << BIO_SEG_VALID); + if (bio_integrity(bio)) { + bio_integrity_clone(clone, bio, bs); + + if (idx != bio->bi_idx || clone->bi_size < bio->bi_size) + bio_integrity_trim(clone, + bio_sector_offset(bio, idx, 0), len); + } + return clone; } @@ -1191,6 +1205,7 @@ static void free_dev(struct mapped_devic mempool_destroy(md->tio_pool); mempool_destroy(md->io_pool); bioset_free(md->bs); + blk_integrity_unregister(md->disk); del_gendisk(md->disk); free_minor(minor);