On Fri, Feb 4, 2011 at 7:45 AM, Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx> wrote: > Please consider the following patch series for mainline target code. > It consists of predominately configfs bugfixes uncovered with recent SLUB > poison testing, and proper removal of legacy procfs target_core_mib.c code. > Note that the complete set of fabric independent statistics (SCSI MIBs) and > fabric dependent statistics will be included as native configfs group context > 'per value' attribute series during the .39 time frame. I'm still not convinced that using configfs in a storage target as the only interface between kernel space and user space is a good idea. While configfs may satisfy all the needs of an iSCSI target, the use of configfs in combination with hot-pluggable HCAs is really awkward. Whenever a HCA is plugged in, the user has to issue mkdir commands to make these interfaces appear in configfs. And whenever a HCA is removed, stale information will remain present in configfs until the user issues an rmdir command. As we all know, it is not possible for a storage target to make these directories appear / disappear automatically in configfs because of basic configfs design choices. Regarding the SCSI-MIB (RFC 4455): using configfs makes it impossible to ensure that the information in the scsiTgtPortEntry table is current. If a HCA is plugged in, it won't appear in that table until the user or some software issues an mkdir command. If a HCA is removed, it won't appear in that table until an rmdir command is issued. All these mkdir / rmdir commands are redundant since the target core already knows which HCAs are available - a natural way to implement a storage target driver that has to handle HCA hot-plugging is to let it tell the storage target core about hot-plug events in the bus add_one / remove_one callbacks. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
