diff options
| -rw-r--r-- | drivers/md/dm-log-userspace-base.c | 35 | ||||
| -rw-r--r-- | include/linux/dm-log-userspace.h | 18 |
2 files changed, 45 insertions, 8 deletions
diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c index 3c27978890b..8db3862dade 100644 --- a/drivers/md/dm-log-userspace-base.c +++ b/drivers/md/dm-log-userspace-base.c @@ -30,6 +30,7 @@ struct flush_entry { struct log_c { struct dm_target *ti; + struct dm_dev *log_dev; uint32_t region_size; region_t region_count; uint64_t luid; @@ -161,13 +162,15 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, struct log_c *lc = NULL; uint64_t rdata; size_t rdata_size = sizeof(rdata); + char *devices_rdata = NULL; + size_t devices_rdata_size = DM_NAME_LEN; if (argc < 3) { DMWARN("Too few arguments to userspace dirty log"); return -EINVAL; } - lc = kmalloc(sizeof(*lc), GFP_KERNEL); + lc = kzalloc(sizeof(*lc), GFP_KERNEL); if (!lc) { DMWARN("Unable to allocate userspace log context."); return -ENOMEM; @@ -195,9 +198,19 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, return str_size; } - /* Send table string */ + devices_rdata = kzalloc(devices_rdata_size, GFP_KERNEL); + if (!devices_rdata) { + DMERR("Failed to allocate memory for device information"); + r = -ENOMEM; + goto out; + } + + /* + * Send table string and get back any opened device. + */ r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR, - ctr_str, str_size, NULL, NULL); + ctr_str, str_size, + devices_rdata, &devices_rdata_size); if (r < 0) { if (r == -ESRCH) @@ -220,7 +233,20 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, lc->region_size = (uint32_t)rdata; lc->region_count = dm_sector_div_up(ti->len, lc->region_size); + if (devices_rdata_size) { + if (devices_rdata[devices_rdata_size - 1] != '\0') { + DMERR("DM_ULOG_CTR device return string not properly terminated"); + r = -EINVAL; + goto out; + } + r = dm_get_device(ti, devices_rdata, + dm_table_get_mode(ti->table), &lc->log_dev); + if (r) + DMERR("Failed to register %s with device-mapper", + devices_rdata); + } out: + kfree(devices_rdata); if (r) { kfree(lc); kfree(ctr_str); @@ -241,6 +267,9 @@ static void userspace_dtr(struct dm_dirty_log *log) NULL, 0, NULL, NULL); + if (lc->log_dev) + dm_put_device(lc->ti, lc->log_dev); + kfree(lc->usr_argv_str); kfree(lc); diff --git a/include/linux/dm-log-userspace.h b/include/linux/dm-log-userspace.h index eeace7d3ff1..0678c2adc42 100644 --- a/include/linux/dm-log-userspace.h +++ b/include/linux/dm-log-userspace.h @@ -52,15 +52,20 @@ * Payload-to-userspace: * A single string containing all the argv arguments separated by ' 's * Payload-to-kernel: - * None. ('data_size' in the dm_ulog_request struct should be 0.) + * A NUL-terminated string that is the name of the device that is used + * as the backing store for the log data. 'dm_get_device' will be called + * on this device. ('dm_put_device' will be called on this device + * automatically after calling DM_ULOG_DTR.) If there is no device needed + * for log data, 'data_size' in the dm_ulog_request struct should be 0. * * The UUID contained in the dm_ulog_request structure is the reference that * will be used by all request types to a specific log. The constructor must - * record this assotiation with instance created. + * record this association with the instance created. * * When the request has been processed, user-space must return the - * dm_ulog_request to the kernel - setting the 'error' field and - * 'data_size' appropriately. + * dm_ulog_request to the kernel - setting the 'error' field, filling the + * data field with the log device if necessary, and setting 'data_size' + * appropriately. */ #define DM_ULOG_CTR 1 @@ -377,8 +382,11 @@ * dm_ulog_request or a change in the way requests are * issued/handled. Changes are outlined here: * version 1: Initial implementation + * version 2: DM_ULOG_CTR allowed to return a string containing a + * device name that is to be registered with DM via + * 'dm_get_device'. */ -#define DM_ULOG_REQUEST_VERSION 1 +#define DM_ULOG_REQUEST_VERSION 2 struct dm_ulog_request { /* |