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* UBI: fix mean EC calculationArtem Bityutskiy2008-04-191-33/+8
| | | | | | | | | | | (a + b) / (c + d) != a / c + b / d. The old code errornously assumed this incorrect formuld. Instead, just sum all erase counters in a 64-bit variable and divide to the number of EBs at the end. Thanks to Adrian Hunter for pointing this out. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: add layout volume informationArtem Bityutskiy2008-01-251-1/+1
| | | | | | | | Add more information about layout volume to make userspace tools use the macros instead of constants. Also rename UBI_LAYOUT_VOL_ID to make it consistent with other macros. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: fix warningsArtem Bityutskiy2008-01-251-1/+1
| | | | | | | | | | | | | | Old gcc complains: CC drivers/mtd/ubi/wl.o drivers/mtd/ubi/wl.c: In function 'wear_leveling_worker': drivers/mtd/ubi/wl.c:746: warning: 'pe' may be used uninitialized in this function CC drivers/mtd/ubi/scan.o drivers/mtd/ubi/scan.c: In function 'ubi_scan': drivers/mtd/ubi/scan.c:772: warning: 'ec' may be used uninitialized in this function drivers/mtd/ubi/scan.c:772: note: 'ec' was declared here Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: add sanity checkArtem Bityutskiy2008-01-251-1/+6
| | | | Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: remove bogus assertionArtem Bityutskiy2008-01-251-1/+0
| | | | Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* Merge branch 'master' of git://git.infradead.org/~dedekind/ubi-2.6David Woodhouse2007-10-141-24/+21
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| * UBI: do not use vmalloc on I/O pathArtem Bityutskiy2007-10-141-11/+8
| | | | | | | | | | | | | | | | | | | | | | Similar reason as in case of the previous patch: it causes deadlocks if a filesystem with writeback support works on top of UBI. So pre-allocate needed buffers when attaching MTD device. We also need mutexes to protect the buffers, but they do not cause much contantion because they are used in recovery, torture, and WL copy routines, which are called seldom. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * UBI: allocate memory with GFP_NOFSArtem Bityutskiy2007-10-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | Use GFP_NOFS flag when allocating memory on I/O path, because otherwise we may deadlock the filesystem which works on top of us. We observed the deadlocks with UBIFS. Example: VFS->FS lock a lock->UBI->kmalloc()->VFS writeback->FS locks the same lock again. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * UBI: fix sparse warningsArtem Bityutskiy2007-10-141-8/+8
| | | | | | | | | | | | | | Fix "symbol shadows an earlier one" warnings. Although they are harmless but it does not hurt to fix them and make sparse happy. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * UBI: fix leak in ubi_scan_erase_pebFlorin Malita2007-10-141-4/+4
| | | | | | | | | | | | | | | | | | | | Coverity (1769) found the following problem: if the erase counter overflow check triggers, ec_hdr is leaked. Moving the allocation after the overflow check should take care of it. Signed-off-by: Florin Malita <fmalita@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* | [UBI] drivers/mtd/ubi/scan.c: kmalloc + memset conversion to kzallocMariusz Kozlowski2007-08-011-9/+8
|/ | | | | | | | To be able to convert kmalloc + memset(..., 1, ...) to kzalloc this patch reverses the logic around 'buf'. Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
* UBI: bugfix in max_sqnum calculationArtem Bityutskiy2007-07-181-1/+0
| | | | | | Do not zero max_sqnum after a new volume has been found. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: bugfix in sqnum calculationBrijesh Singh2007-07-181-3/+3
| | | | | | | | | | | | | Hi,I came across problem of having two leb with same sequence no.This happens when we continuously write one block again and again and reboot machine before background thread erases those blocks. The problem here was,when we find two blocks with same sequence no,we take the higher one,but we were not updating max seq no,so next block may have the same seqnum. This patch solves this problem. Signed-off-by: Brijesh Singh <brijesh.s.singh@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: kill homegrown endian macrosChristoph Hellwig2007-07-181-28/+28
| | | | | | | | Kill UBI's homegrown endianess handling and replace it with the standard kernel endianess handling. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: use vmalloc for large buffersArtem Bityutskiy2007-07-181-3/+3
| | | | | | | UBI allocates temporary buffers of PEB size, which may be 256KiB. Use vmalloc instead of kmalloc for such big temporary buffers. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: add few more commentsArtem Bityutskiy2007-07-181-2/+6
| | | | | | | Add few comments above ubi_scan_add_used() to explain why it is so complex. Requested by Satyam Sharma <satyam.sharma@gmail.com>. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: set correct gluebi device sizeArtem Bityutskiy2007-07-181-1/+1
| | | | | | | | In case of static volumes, make emulated MTD device size to be equivalent to data size, rather then volume size. Reported-by: John Smith <john@arrows.demon.co.uk> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: fix error path in create_vtbl()Artem Bityutskiy2007-07-181-19/+27
| | | | | | | | | | | There were several bugs in volume table creation error path. Thanks to Satyam Sharma <satyam.sharma@gmail.com> and Florin Malita <fmalita@gmail.com> for finding and analysing them: http://lkml.org/lkml/2007/5/3/274 This patch makes ubi_scan_add_to_list() static and renames it to add_to_list(), just because it is not needed outside scan.c anymore. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: fix memory leak in checking codeArtem Bityutskiy2007-07-181-1/+3
| | | | | Reported-by: Eric Sesterhenn / Snakebyte <snakebyte@gmx.de> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: Unsorted Block ImagesArtem B. Bityutskiy2007-04-271-0/+1368
UBI (Latin: "where?") manages multiple logical volumes on a single flash device, specifically supporting NAND flash devices. UBI provides a flexible partitioning concept which still allows for wear-levelling across the whole flash device. In a sense, UBI may be compared to the Logical Volume Manager (LVM). Whereas LVM maps logical sector numbers to physical HDD sector numbers, UBI maps logical eraseblocks to physical eraseblocks. More information may be found at http://www.linux-mtd.infradead.org/doc/ubi.html Partitioning/Re-partitioning An UBI volume occupies a certain number of erase blocks. This is limited by a configured maximum volume size, which could also be viewed as the partition size. Each individual UBI volume's size can be changed independently of the other UBI volumes, provided that the sum of all volume sizes doesn't exceed a certain limit. UBI supports dynamic volumes and static volumes. Static volumes are read-only and their contents are protected by CRC check sums. Bad eraseblocks handling UBI transparently handles bad eraseblocks. When a physical eraseblock becomes bad, it is substituted by a good physical eraseblock, and the user does not even notice this. Scrubbing On a NAND flash bit flips can occur on any write operation, sometimes also on read. If bit flips persist on the device, at first they can still be corrected by ECC, but once they accumulate, correction will become impossible. Thus it is best to actively scrub the affected eraseblock, by first copying it to a free eraseblock and then erasing the original. The UBI layer performs this type of scrubbing under the covers, transparently to the UBI volume users. Erase Counts UBI maintains an erase count header per eraseblock. This frees higher-level layers (like file systems) from doing this and allows for centralized erase count management instead. The erase counts are used by the wear-levelling algorithm in the UBI layer. The algorithm itself is exchangeable. Booting from NAND For booting directly from NAND flash the hardware must at least be capable of fetching and executing a small portion of the NAND flash. Some NAND flash controllers have this kind of support. They usually limit the window to a few kilobytes in erase block 0. This "initial program loader" (IPL) must then contain sufficient logic to load and execute the next boot phase. Due to bad eraseblocks, which may be randomly scattered over the flash device, it is problematic to store the "secondary program loader" (SPL) statically. Also, due to bit-flips it may become corrupted over time. UBI allows to solve this problem gracefully by storing the SPL in a small static UBI volume. UBI volumes vs. static partitions UBI volumes are still very similar to static MTD partitions: * both consist of eraseblocks (logical eraseblocks in case of UBI volumes, and physical eraseblocks in case of static partitions; * both support three basic operations - read, write, erase. But UBI volumes have the following advantages over traditional static MTD partitions: * there are no eraseblock wear-leveling constraints in case of UBI volumes, so the user should not care about this; * there are no bit-flips and bad eraseblocks in case of UBI volumes. So, UBI volumes may be considered as flash devices with relaxed restrictions. Where can it be found? Documentation, kernel code and applications can be found in the MTD gits. What are the applications for? The applications help to create binary flash images for two purposes: pfi files (partial flash images) for in-system update of UBI volumes, and plain binary images, with or without OOB data in case of NAND, for a manufacturing step. Furthermore some tools are/and will be created that allow flash content analysis after a system has crashed.. Who did UBI? The original ideas, where UBI is based on, were developed by Andreas Arnez, Frank Haverkamp and Thomas Gleixner. Josh W. Boyer and some others were involved too. The implementation of the kernel layer was done by Artem B. Bityutskiy. The user-space applications and tools were written by Oliver Lohmann with contributions from Frank Haverkamp, Andreas Arnez, and Artem. Joern Engel contributed a patch which modifies JFFS2 so that it can be run on a UBI volume. Thomas Gleixner did modifications to the NAND layer. Alexander Schmidt made some testing work as well as core functionality improvements. Signed-off-by: Artem B. Bityutskiy <dedekind@linutronix.de> Signed-off-by: Frank Haverkamp <haver@vnet.ibm.com>
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