The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5b0fab508992c2e120971da658ce80027acbc405 Mon Sep 17 00:00:00 2001

From: Jeffle Xu jefflexu@linux.alibaba.com Date: Mon, 8 Feb 2021 22:34:36 -0500 Subject: [PATCH] dm table: fix DAX iterate_devices based device capability checks

Fix dm_table_supports_dax() and invert logic of both iterate_devices_callout_fn so that all devices' DAX capabilities are properly checked.

Fixes: 545ed20e6df6 ("dm: add infrastructure for DAX support") Cc: stable@vger.kernel.org Signed-off-by: Jeffle Xu jefflexu@linux.alibaba.com Signed-off-by: Mike Snitzer snitzer@redhat.com

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 3e211e64f348..71f7ec508cf7 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -820,24 +820,24 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type) EXPORT_SYMBOL_GPL(dm_table_set_type);

/* validate the dax capability of the target device span */ -int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, +int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { int blocksize = *(int *) data, id; bool rc;

id = dax_read_lock(); - rc = dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len); + rc = !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len); dax_read_unlock(id);

return rc; }

/* Check devices support synchronous DAX */ -static int device_dax_synchronous(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) +static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) { - return dev->dax_dev && dax_synchronous(dev->dax_dev); + return !dev->dax_dev || !dax_synchronous(dev->dax_dev); }

bool dm_table_supports_dax(struct dm_table *t, @@ -854,7 +854,7 @@ bool dm_table_supports_dax(struct dm_table *t, return false;

if (!ti->type->iterate_devices || - !ti->type->iterate_devices(ti, iterate_fn, blocksize)) + ti->type->iterate_devices(ti, iterate_fn, blocksize)) return false; }

@@ -925,7 +925,7 @@ static int dm_table_determine_type(struct dm_table *t) verify_bio_based: /* We must use this table as bio-based */ t->type = DM_TYPE_BIO_BASED; - if (dm_table_supports_dax(t, device_supports_dax, &page_size) || + if (dm_table_supports_dax(t, device_not_dax_capable, &page_size) || (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) { t->type = DM_TYPE_DAX_BIO_BASED; } @@ -1618,23 +1618,6 @@ static int device_dax_write_cache_enabled(struct dm_target *ti, return false; }

-static int dm_table_supports_dax_write_cache(struct dm_table *t) -{ - struct dm_target *ti; - unsigned i; - - for (i = 0; i < dm_table_get_num_targets(t); i++) { - ti = dm_table_get_target(t, i); - - if (ti->type->iterate_devices && - ti->type->iterate_devices(ti, - device_dax_write_cache_enabled, NULL)) - return true; - } - - return false; -} - static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1839,15 +1822,15 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } blk_queue_write_cache(q, wc, fua);

- if (dm_table_supports_dax(t, device_supports_dax, &page_size)) { + if (dm_table_supports_dax(t, device_not_dax_capable, &page_size)) { blk_queue_flag_set(QUEUE_FLAG_DAX, q); - if (dm_table_supports_dax(t, device_dax_synchronous, NULL)) + if (dm_table_supports_dax(t, device_not_dax_synchronous_capable, NULL)) set_dax_synchronous(t->md->dax_dev); } else blk_queue_flag_clear(QUEUE_FLAG_DAX, q);

- if (dm_table_supports_dax_write_cache(t)) + if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled)) dax_write_cache(t->md->dax_dev, true);

/* Ensure that all underlying devices are non-rotational. */ diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 65b21159a7a6..64fda1429e39 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1133,7 +1133,7 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd if (!map) goto out;

- ret = dm_table_supports_dax(map, device_supports_dax, &blocksize); + ret = dm_table_supports_dax(map, device_not_dax_capable, &blocksize);

out: dm_put_live_table(md, srcu_idx); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index fffe1e289c53..b441ad772c18 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -73,7 +73,7 @@ void dm_table_free_md_mempools(struct dm_table *t); struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn, int *blocksize); -int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, +int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data);

void dm_lock_md_type(struct mapped_device *md);