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path: root/drivers/mtd/ubi/ubi.h
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2008-07-24UBI: fix kernel-doc errors and warningsArtem Bityutskiy
No functional changes, just tweak comments to make kernel-doc work fine and stop complaining. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-07-24UBI: fix checkpatch.pl errors and warningsArtem Bityutskiy
Just out or curiousity ran checkpatch.pl for whole UBI, and discovered there are quite a few of stylistic issues. Fix them. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-07-24UBI: implement multiple volumes renameArtem Bityutskiy
Quite useful ioctl which allows to make atomic system upgrades. The idea belongs to Richard Titmuss <richard_titmuss@logitech.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-07-24UBI: amend commentariesArtem Bityutskiy
Hch asked not to use "unit" for sub-systems, let it be so. Also some other commentaries modifications. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-07-24UBI: fix memory leakArtem Bityutskiy
ubi_free_volume() function sets ubi->volumes[] to NULL, so ubi_eba_close() is useless, it does not free what has to be freed. So zap it and free vol->eba_tbl at the volume release function. Pointed-out-by: Adrian Hunter <ext-adrian.hunter@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-04-23Merge git://git.infradead.org/~dedekind/ubi-2.6David Woodhouse
2008-04-22[MTD] replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2008-04-17UBI: make ubi-header.h localArtem Bityutskiy
The new trend in linux is not to store headers which define on-media format in the include/ directory, but instead, store them locally. This is because these headers "do not define any kernel<->userspace interface". Do so for UBI as well. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-03-04UBI: fix sparse errors in ubi.hHarvey Harrison
In C, signed 1-bit bitfields can only take the values 0 and -1, only 0 and 1 are ever assigned in current code. Make them unsigned bitfields. Fixes the (repeated) sparse errors: drivers/mtd/ubi/ubi.h:220:15: error: dubious one-bit signed bitfield drivers/mtd/ubi/ubi.h:221:17: error: dubious one-bit signed bitfield drivers/mtd/ubi/ubi.h:222:18: error: dubious one-bit signed bitfield drivers/mtd/ubi/ubi.h:223:16: error: dubious one-bit signed bitfield drivers/mtd/ubi/ubi.h:224:20: error: dubious one-bit signed bitfield Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-01-25UBI: implement atomic LEB change ioctlArtem Bityutskiy
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-01-25UBI: simplify internal interfacesArtem Bityutskiy
Instead of passing vol_id to all functions and then find struct ubi_volume, pass struct ubi_volume pointer. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-01-25UBI: add auto-resize featureArtem Bityutskiy
The problem: NAND flashes have different amount of initial bad physical eraseblocks (marked as bad by the manufacturer). For example, for 256MiB Samsung OneNAND flash there might be from 0 to 40 bad initial eraseblocks, which is about 2%. When UBI is used as the base system, one needs to know the exact amount of good physical eraseblocks, because this number is needed to create the UBI image which is put to the devices during production. But this number is not know, which forces us to use the minimum number of good physical eraseblocks. And UBI additionally reserves some percentage of physical eraseblocks for bad block handling (default is 1%), so we have 1-3% of PEBs reserved at the end, depending on the amount of initial bad PEBs. But it is desired to always have 1% (or more, depending on the configuration). Solution: this patch adds an "auto-resize" flag to the volume table. The volume which has the "auto-resize" flag will automatically be re-sized (enlarged) on the first UBI initialization. UBI clears the flag when the volume is re-sized. Only one volume may have the "auto-resize" flag. So, the production UBI image may have one volume with "auto-resize" flag set, and its size is automatically adjusted on the first boot of the device. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-01-25UBI: use bit-fieldsArtem Bityutskiy
Save 12 bytes of RAM per volume by using bit-fields instead of integers. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-01-25UBI: get rid of ubi_ltree_slabArtem Bityutskiy
This slab cache is not really needed since the number of objects is low and the constructor does not make much sense because we allocate oblects when doint I/O, which is way slower then allocation. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: use separate mutex for volumes checkingArtem Bityutskiy
Introduce a separate mutex which serializes volumes checking, because we cammot really use volumes_mutex - it cases reverse locking problems with mtd_tbl_mutex when gluebi is used - thanks to lockdep. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: handle attach ioctlArtem Bityutskiy
Actually implement the MTD device attach/detach handlers. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: remove data_offsetArtem Bityutskiy
'data_offset' parameter does not really make sense and it is not needed. Get rid of it. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: prepare attach and detach functionsArtem Bityutskiy
Prepare the attach and detach functions to by used outside of module initialization: * detach function checks reference count before detaching * it kills the background thread as well Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: add UBI devices reference countingArtem Bityutskiy
This is one more step on the way to "removable" UBI devices. It adds reference counting for UBI devices. Every time a volume on this device is opened - the device's refcount is increased. It is also increased if someone is reading any sysfs file of this UBI device or of one of its volumes. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: add UBI control deviceArtem Bityutskiy
This patch is a preparation to make UBI devices dynamic. It adds an UBI control device which has dynamically allocated major number and registers itself as "ubi_ctrl". It does not do anything so far. The idea is that this device will allow to attach/detach MTD devices from userspace. This is symilar to what the Linux device mapper has. The next things to do are: * Fix UBI, because it now assumes UBI devices cannot go away * Implement control device ioctls which will attach/detach MTD devices Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: fix ubi_wl_flushArtem Bityutskiy
The flush function should finish all the pending jobs. But if somebody else is doing a work, this function should wait and let it finish. This patche uses rw semaphore for synchronization purpose - it just looks quite convinient. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: bugfix: protect from volume removalArtem Bityutskiy
When the WL worker is moving an LEB, the volume might go away occasionally. UBI does not handle these situations correctly. This patch introduces a new mutex which serializes wear-levelling worker and the the 'ubi_wl_put_peb()' function. Now, if one puts an LEB, and its PEB is being moved, it will wait on the mutex. And because we unmap all LEBs when removing volumes, this will make the volume remove function to wait while the LEB movement finishes. Below is an example of an oops which should be fixed by this patch: Pid: 9167, comm: io_paral Not tainted (2.6.24-rc5-ubi-2.6.git #2) EIP: 0060:[<f884a379>] EFLAGS: 00010246 CPU: 0 EIP is at prot_tree_del+0x2a/0x63 [ubi] EAX: f39a90e0 EBX: 00000000 ECX: 00000000 EDX: 00000134 ESI: f39a90e0 EDI: f39a90e0 EBP: f2d55ddc ESP: f2d55dd4 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Process io_paral (pid: 9167, ti=f2d54000 task=f72a8030 task.ti=f2d54000) Stack: f39a95f8 ef6aae50 f2d55e08 f884a511 f88538e1 f884ecea 00000134 00000000 f39a9604 f39a95f0 efea8280 00000000 f39a90e0 f2d55e40 f8847261 f8850c3c f884eaad 00000001 000000b9 00000134 00000172 000000b9 00000134 00000001 Call Trace: [<c0105227>] show_trace_log_lvl+0x1a/0x30 [<c01052e2>] show_stack_log_lvl+0xa5/0xca [<c01053d6>] show_registers+0xcf/0x21b [<c0105648>] die+0x126/0x224 [<c0119a62>] do_page_fault+0x27f/0x60d [<c037dd62>] error_code+0x72/0x78 [<f884a511>] ubi_wl_put_peb+0xf0/0x191 [ubi] [<f8847261>] ubi_eba_unmap_leb+0xaf/0xcc [ubi] [<f8843c21>] ubi_remove_volume+0x102/0x1e8 [ubi] [<f8846077>] ubi_cdev_ioctl+0x22a/0x383 [ubi] [<c017d768>] do_ioctl+0x68/0x71 [<c017d7c6>] vfs_ioctl+0x55/0x271 [<c017da15>] sys_ioctl+0x33/0x52 [<c0104152>] sysenter_past_esp+0x5f/0xa5 ======================= Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: introduce volume refcountingArtem Bityutskiy
Add ref_count field to UBI volumes and remove weired "vol->removed" field. This way things are better understandable and we do not have to do whold show_attr operation under spinlock. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: tweak volumes lockingArtem Bityutskiy
Transform vtbl_mutex to volumes_mutex - this just makes code easier to understand. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: improve internal interfacesArtem Bityutskiy
Pass volume description object to the EBA function which makes more sense, and EBA function do not have to find the volume description object by volume ID. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: remove ubi_devices_cntArtem Bityutskiy
This global variablea is not really needed, remove it Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: create ubi_wl_entry slab on initializationArtem Bityutskiy
Similarly to ltree_entry_slab, it makes more sense to create and destroy ubi_wl_entry slab on module initialization/exit. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: create ltree_entry slab on initializationArtem Bityutskiy
Since the ltree_entry slab cache is a global entity, which is used by all UBI devices, it is more logical to create it on module initialization time and destro on module exit time. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26UBI: remove redundant fieldArtem Bityutskiy
Remove redundant ubi->major field - we have it in ubi->cdev.dev already. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-10-14UBI: fix atomic LEB change problemsArtem Bityutskiy
When the UBI device is nearly full, i.e. all LEBs are mapped, we have only one spare LEB left - the one we reserved for WL purposes. Well, I do not count the LEBs which were reserved for bad PEB handling - suppose NOR flash for simplicity. If an "atomic LEB change operation" is run, and the WL unit is moving a LEB, we have no spare LEBs to finish the operation and fail, which is not good. Moreover, if there are 2 or more simultanious "atomic LEB change" requests, only one of them has chances to succeed, the other will fail with -ENOSPC. Not good either. This patch does 2 things: 1. Reserves one PEB for the "atomic LEB change" operation. 2. Serealize the operations so that only on of them may run at a time (by means of a mutex). Pointed-to-by: Brijesh Singh <brijesh.s.singh@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-10-14UBI: do not use vmalloc on I/O pathArtem Bityutskiy
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>
2007-10-14UBI: allocate memory with GFP_NOFSArtem Bityutskiy
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>
2007-07-18UBI: use vmalloc for large buffersArtem Bityutskiy
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>
2007-07-18UBI: set correct gluebi device sizeArtem Bityutskiy
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>
2007-04-27UBI: Unsorted Block ImagesArtem B. Bityutskiy
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>