10  * This file includes volume table manipulation code. The volume table is an
11  * on-flash table containing volume meta-data like name, number of reserved
12  * physical eraseblocks, type, etc. The volume table is stored in the so-called
13  * "layout volume".
15  * The layout volume is an internal volume which is organized as follows. It
17  * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each
18  * other. This redundancy guarantees robustness to unclean reboots. The volume
19  * table is basically an array of volume table records. Each record contains
20  * full information about the volume and protected by a CRC checksum. Note,
21  * nowadays we use the atomic LEB change operation when updating the volume
25  * When the volume table is changed, it is first changed in RAM. Then LEB 0 is
26  * erased, and the updated volume table is written back to LEB 0. Then same for
29  * In this UBI implementation the on-flash volume table does not contain any
32  * But it would still be beneficial to store this information in the volume
33  * table. For example, suppose we have a static volume X, and all its physical
36  * corresponding to the volume X. According to the volume table volume X does
40  * The volume table also stores so-called "update marker", which is used for
41  * volume updates. Before updating the volume, the update marker is set, and
44  * update marker is still there and we know that the volume's contents is
56 /* Empty volume table record */
80  * ubi_change_vtbl_record - change volume table record.
83  * @vtbl_rec: new volume table record
85  * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty
86  * volume table record is written. The caller does not have to calculate CRC of
113  * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table.
117  * This function re-names multiple volumes specified in @req in the volume
150  * vtbl_check - check if volume table is not corrupted and sensible.
152  * @vtbl: volume table
270 	ubi_err(ubi, "volume table check failed: record %d, error %d", i, err);  in vtbl_check()
276  * create_vtbl - create a copy of volume table.
279  * @copy: number of the volume table copy
280  * @vtbl: contents of the volume table
293 	dbg_gen("create volume table (copy #%d)", copy + 1);  in create_vtbl()
321 	/* Write the layout volume contents */  in create_vtbl()
352  * process_lvol - process the layout volume.
355  * @av: layout volume attaching information
357  * This function is responsible for reading the layout volume, ensuring it is
358  * not corrupted, and recovering from corruptions if needed. Returns volume
373 	 * volume:  in process_lvol()
396 	dbg_gen("check layout volume");  in process_lvol()
437 			ubi_warn(ubi, "volume table copy #2 is corrupted");  in process_lvol()
441 			ubi_msg(ubi, "volume table was restored");  in process_lvol()
456 			ubi_err(ubi, "both volume tables are corrupted");  in process_lvol()
460 		ubi_warn(ubi, "volume table copy #1 is corrupted");  in process_lvol()
464 		ubi_msg(ubi, "volume table was restored");  in process_lvol()
477  * create_empty_lvol - create empty layout volume.
481  * This function returns volume table contents in case of success and a
511  * init_volumes - initialize volume information for existing volumes.
514  * @vtbl: volume table
516  * This function allocates volume description objects for existing volumes.
554 			/* Auto re-size flag may be set only for one volume */  in init_volumes()
556 				ubi_err(ubi, "more than one auto-resize volume (%d and %d)",  in init_volumes()
574 		 * resize/check the bitmap upon volume resize too.  in init_volumes()
582 		 * In case of dynamic volume UBI knows nothing about how many  in init_volumes()
583 		 * data is stored there. So assume the whole volume is used.  in init_volumes()
597 			 * No eraseblocks belonging to this volume found. We  in init_volumes()
598 			 * don't actually know whether this static volume is  in init_volumes()
601 			 * stored on flash. So we just assume the volume is  in init_volumes()
609 			 * We found a static volume which misses several  in init_volumes()
612 			ubi_warn(ubi, "static volume %d misses %d LEBs - corrupted",  in init_volumes()
625 	/* And add the layout volume */  in init_volumes()
667  * check_av - check volume attaching information.
668  * @vol: UBI volume description object
669  * @av: volume attaching information
671  * This function returns zero if the volume attaching information is consistent
672  * to the data read from the volume tabla, and %-EINVAL if not.
715  * the information read from the volume table. Returns zero if the attaching
733 		ubi_err(ubi, "too large volume ID %d found",  in check_attaching_info()
756 			 * During attaching we found a volume which does not  in check_attaching_info()
757 			 * exist according to the information in the volume  in check_attaching_info()
759 			 * reboot while the volume was being removed. Discard  in check_attaching_info()
762 			ubi_msg(ubi, "finish volume %d removal", av->vol_id);  in check_attaching_info()
775  * ubi_read_volume_table - read the volume table.
779  * This function reads volume table, checks it, recover from errors if needed,
796 		ubi_err(ubi, "LEB size too small for a volume record");  in ubi_read_volume_table()
810 		 * No logical eraseblocks belonging to the layout volume were  in ubi_read_volume_table()
812 		 * this case we create empty layout volume.  in ubi_read_volume_table()
822 			ubi_err(ubi, "the layout volume was not found");  in ubi_read_volume_table()
828 			ubi_err(ubi, "too many LEBs (%d) in layout volume",  in ubi_read_volume_table()
841 	 * The layout volume is OK, initialize the corresponding in-RAM data  in ubi_read_volume_table()
850 	 * information stored in the volume table.  in ubi_read_volume_table()
865  * self_vtbl_check - check volume table.