The patch below does not apply to the 4.14-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 a4c8dd9c2d0987cf542a2a0c42684c9c6d78a04e Mon Sep 17 00:00:00 2001
From: Jeffle Xu jefflexu@linux.alibaba.com Date: Tue, 2 Feb 2021 11:35:28 +0800 Subject: [PATCH] dm table: fix iterate_devices based device capability checks
According to the definition of dm_iterate_devices_fn: * This function must iterate through each section of device used by the * target until it encounters a non-zero return code, which it then returns. * Returns zero if no callout returned non-zero.
For some target type (e.g. dm-stripe), one call of iterate_devices() may iterate multiple underlying devices internally, in which case a non-zero return code returned by iterate_devices_callout_fn will stop the iteration in advance. No iterate_devices_callout_fn should return non-zero unless device iteration should stop.
Rename dm_table_requires_stable_pages() to dm_table_any_dev_attr() and elevate it for reuse to stop iterating (and return non-zero) on the first device that causes iterate_devices_callout_fn to return non-zero. Use dm_table_any_dev_attr() to properly iterate through devices.
Rename device_is_nonrot() to device_is_rotational() and invert logic accordingly to fix improper disposition.
Fixes: c3c4555edd10 ("dm table: clear add_random unless all devices have it set") Fixes: 4693c9668fdc ("dm table: propagate non rotational flag") 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 4acf2342f7ad..3e211e64f348 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1295,6 +1295,46 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) return &t->targets[(KEYS_PER_NODE * n) + k]; }
+/* + * type->iterate_devices() should be called when the sanity check needs to + * iterate and check all underlying data devices. iterate_devices() will + * iterate all underlying data devices until it encounters a non-zero return + * code, returned by whether the input iterate_devices_callout_fn, or + * iterate_devices() itself internally. + * + * For some target type (e.g. dm-stripe), one call of iterate_devices() may + * iterate multiple underlying devices internally, in which case a non-zero + * return code returned by iterate_devices_callout_fn will stop the iteration + * in advance. + * + * Cases requiring _any_ underlying device supporting some kind of attribute, + * should use the iteration structure like dm_table_any_dev_attr(), or call + * it directly. @func should handle semantics of positive examples, e.g. + * capable of something. + * + * Cases requiring _all_ underlying devices supporting some kind of attribute, + * should use the iteration structure like dm_table_supports_nowait() or + * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that + * uses an @anti_func that handle semantics of counter examples, e.g. not + * capable of something. So: return !dm_table_any_dev_attr(t, anti_func); + */ +static bool dm_table_any_dev_attr(struct dm_table *t, + iterate_devices_callout_fn func) +{ + struct dm_target *ti; + unsigned int 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, func, NULL)) + return true; + } + + return false; +} + static int count_device(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1595,12 +1635,12 @@ static int dm_table_supports_dax_write_cache(struct dm_table *t) return false; }
-static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) +static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) { struct request_queue *q = bdev_get_queue(dev->bdev);
- return q && blk_queue_nonrot(q); + return q && !blk_queue_nonrot(q); }
static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev, @@ -1611,23 +1651,6 @@ static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev, return q && !blk_queue_add_random(q); }
-static bool dm_table_all_devices_attribute(struct dm_table *t, - iterate_devices_callout_fn func) -{ - 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, func, NULL)) - return false; - } - - return true; -} - static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1779,27 +1802,6 @@ static int device_requires_stable_pages(struct dm_target *ti, return q && blk_queue_stable_writes(q); }
-/* - * If any underlying device requires stable pages, a table must require - * them as well. Only targets that support iterate_devices are considered: - * don't want error, zero, etc to require stable pages. - */ -static bool dm_table_requires_stable_pages(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_requires_stable_pages, NULL)) - return true; - } - - return false; -} - void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { @@ -1849,10 +1851,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, dax_write_cache(t->md->dax_dev, true);
/* Ensure that all underlying devices are non-rotational. */ - if (dm_table_all_devices_attribute(t, device_is_nonrot)) - blk_queue_flag_set(QUEUE_FLAG_NONROT, q); - else + if (dm_table_any_dev_attr(t, device_is_rotational)) blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); + else + blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
if (!dm_table_supports_write_same(t)) q->limits.max_write_same_sectors = 0; @@ -1864,8 +1866,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, /* * Some devices don't use blk_integrity but still want stable pages * because they do their own checksumming. + * If any underlying device requires stable pages, a table must require + * them as well. Only targets that support iterate_devices are considered: + * don't want error, zero, etc to require stable pages. */ - if (dm_table_requires_stable_pages(t)) + if (dm_table_any_dev_attr(t, device_requires_stable_pages)) blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q); else blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q); @@ -1876,7 +1881,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not * have it set. */ - if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random)) + if (blk_queue_add_random(q) && dm_table_any_dev_attr(t, device_is_not_random)) blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
/*