From 08976cb548d67d8a492d75c9202fde28e21915e2 Mon Sep 17 00:00:00 2001 From: Bodo Stroesser Date: Wed, 24 Mar 2021 20:57:58 +0100 Subject: [PATCH] scsi: target: tcmu: Make data_pages_per_blk changeable via configfs Make data_pages_per_blk changeable similar to the way it is done for max_data_area_mb. One can change the value by typing: echo "data_pages_per_blk=N" >control The value is printed when doing: cat info In addition, a new readonly attribute 'data_pages_per_blk' returns the value on read. Link: https://lore.kernel.org/r/20210324195758.2021-7-bostroesser@gmail.com Signed-off-by: Bodo Stroesser Signed-off-by: Martin K. Petersen --- drivers/target/target_core_user.c | 55 +++++++++++++++++++++++++++++-- 1 file changed, 53 insertions(+), 2 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 3de66db06438..eec2fd573e2b 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -2331,7 +2331,8 @@ static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level) enum { Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors, - Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err, + Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk, + Opt_err, }; static match_table_t tokens = { @@ -2341,6 +2342,7 @@ static match_table_t tokens = { {Opt_hw_max_sectors, "hw_max_sectors=%d"}, {Opt_nl_reply_supported, "nl_reply_supported=%d"}, {Opt_max_data_area_mb, "max_data_area_mb=%d"}, + {Opt_data_pages_per_blk, "data_pages_per_blk=%d"}, {Opt_err, NULL} }; @@ -2405,6 +2407,39 @@ unlock: return ret; } +static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg) +{ + int val, ret; + + ret = match_int(arg, &val); + if (ret < 0) { + pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n", + ret); + return ret; + } + + if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) { + pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n", + val, udev->data_area_mb, + TCMU_MBS_TO_PAGES(udev->data_area_mb)); + return -EINVAL; + } + + mutex_lock(&udev->cmdr_lock); + if (udev->data_bitmap) { + pr_err("Cannot set data_pages_per_blk after it has been enabled.\n"); + ret = -EINVAL; + goto unlock; + } + + udev->data_pages_per_blk = val; + udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val; + +unlock: + mutex_unlock(&udev->cmdr_lock); + return ret; +} + static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, const char *page, ssize_t count) { @@ -2456,6 +2491,9 @@ static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, case Opt_max_data_area_mb: ret = tcmu_set_max_blocks_param(udev, &args[0]); break; + case Opt_data_pages_per_blk: + ret = tcmu_set_data_pages_per_blk(udev, &args[0]); + break; default: break; } @@ -2476,7 +2514,8 @@ static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b) bl = sprintf(b + bl, "Config: %s ", udev->dev_config[0] ? udev->dev_config : "NULL"); bl += sprintf(b + bl, "Size: %llu ", udev->dev_size); - bl += sprintf(b + bl, "MaxDataAreaMB: %u\n", udev->data_area_mb); + bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb); + bl += sprintf(b + bl, "DataPagesPerBlk: %u\n", udev->data_pages_per_blk); return bl; } @@ -2574,6 +2613,17 @@ static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page) } CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb); +static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item, + char *page) +{ + struct se_dev_attrib *da = container_of(to_config_group(item), + struct se_dev_attrib, da_group); + struct tcmu_dev *udev = TCMU_DEV(da->da_dev); + + return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk); +} +CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk); + static ssize_t tcmu_dev_config_show(struct config_item *item, char *page) { struct se_dev_attrib *da = container_of(to_config_group(item), @@ -2885,6 +2935,7 @@ static struct configfs_attribute *tcmu_attrib_attrs[] = { &tcmu_attr_cmd_time_out, &tcmu_attr_qfull_time_out, &tcmu_attr_max_data_area_mb, + &tcmu_attr_data_pages_per_blk, &tcmu_attr_dev_config, &tcmu_attr_dev_size, &tcmu_attr_emulate_write_cache,