This issue was found and also debugged by Carl Lei <me@xxxxxxxxxxxx>. If the device is not enabled, iblock/file will have not setup their se_device to bdev/file mappings. If a user tries to config the unmap settings at this time, we will then crash trying to access a NULL pointer where the bdev/file should be. This patch adds a check to make sure the device is configured before we try to call the configure_unmap callout. Fixes: 34bd1dcacf0d ("scsi: target: Detect UNMAP support post configuration") Reported-by: Carl Lei <me@xxxxxxxxxxxx> Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx> --- drivers/target/target_core_configfs.c | 46 +++++++++++++++++---------- 1 file changed, 30 insertions(+), 16 deletions(-) diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index a5f58988130a..d87f6eba4eda 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -759,6 +759,27 @@ static ssize_t emulate_tas_store(struct config_item *item, return count; } +static int target_try_configure_unmap(struct se_device *dev, + const char *config_opt) +{ + if (!dev->transport->configure_unmap) + return 0; + + if (!target_dev_configured(dev)) { + pr_err("Generic Block Discard setup for %s requires device to be configured\n", + config_opt); + return -ENODEV; + } + + if (!dev->transport->configure_unmap(dev)) { + pr_err("Generic Block Discard setup for %s failed\n", + config_opt); + return -ENOSYS; + } + + return 0; +} + static ssize_t emulate_tpu_store(struct config_item *item, const char *page, size_t count) { @@ -776,11 +797,9 @@ static ssize_t emulate_tpu_store(struct config_item *item, * Discard supported is detected iblock_create_virtdevice(). */ if (flag && !da->max_unmap_block_desc_count) { - if (!dev->transport->configure_unmap || - !dev->transport->configure_unmap(dev)) { - pr_err("Generic Block Discard not supported\n"); - return -ENOSYS; - } + ret = target_try_configure_unmap(dev, "emulate_tpu"); + if (ret) + return ret; } da->emulate_tpu = flag; @@ -806,11 +825,9 @@ static ssize_t emulate_tpws_store(struct config_item *item, * Discard supported is detected iblock_create_virtdevice(). */ if (flag && !da->max_unmap_block_desc_count) { - if (!dev->transport->configure_unmap || - !dev->transport->configure_unmap(dev)) { - pr_err("Generic Block Discard not supported\n"); - return -ENOSYS; - } + ret = target_try_configure_unmap(dev, "emulate_tpws"); + if (ret) + return ret; } da->emulate_tpws = flag; @@ -1022,12 +1039,9 @@ static ssize_t unmap_zeroes_data_store(struct config_item *item, * Discard supported is detected iblock_configure_device(). */ if (flag && !da->max_unmap_block_desc_count) { - if (!dev->transport->configure_unmap || - !dev->transport->configure_unmap(dev)) { - pr_err("dev[%p]: Thin Provisioning LBPRZ will not be set because max_unmap_block_desc_count is zero\n", - da->da_dev); - return -ENOSYS; - } + ret = target_try_configure_unmap(dev, "unmap_zeroes_data"); + if (ret) + return ret; } da->unmap_zeroes_data = flag; pr_debug("dev[%p]: SE Device Thin Provisioning LBPRZ bit: %d\n", -- 2.34.1