path: root/drivers/mtd/ubi/kapi.c
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* UBI: fix s/then/than/ typosShinya Kuribayashi2010-05-071-3/+3
| | | | | Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* UBI: add more checks to chdev openArtem Bityutskiy2010-01-121-8/+7
| | | | | | | | When opening UBI volumes by their character device names, make sure we are opening character devices, not block devices or any other inode type. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: Add ubi_open_volume_pathCorentin Chary2009-11-241-0/+40
| | | | | | | | | | | | | Add an 'ubi_open_volume_path(path, mode)' function which works like 'open_bdev_exclusive(path, mode, ...)' where path is the special file representing the UBI volume, typically /dev/ubi0_0. This is needed to teach UBIFS being able to mount UBI character devices. [Comments and the patch were amended a bit by Artem] Signed-off-by: Corentin Chary <corentincj@iksaif.net> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: add notification APIDmitry Pervushin2009-06-021-16/+92
| | | | | | | | | | | | | | | | | | | | UBI volume notifications are intended to create the API to get clients notified about volume creation/deletion, renaming and re-sizing. A client can subscribe to these notifications using 'ubi_volume_register()' and cancel the subscription using 'ubi_volume_unregister()'. When UBI volumes change, a blocking notifier is called. Clients also can request "added" events on all volumes that existed before client subscribed to the notifications. If we use notifications instead of calling functions like 'ubi_gluebi_xxx()', we can make the MTD emulation layer to be more flexible: build it as a separate module and load/unload it on demand. [Artem: many cleanups, rework locking, add "updated" event, provide device/volume info in notifiers] Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: improve debugging messagesArtem Bityutskiy2009-05-181-3/+6
| | | | | | | Various minor improvements to the debugging messages which I found useful while hunting problems. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* fix similar typos to successfullColy Li2009-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | When I review ocfs2 code, find there are 2 typos to "successfull". After doing grep "successfull " in kernel tree, 22 typos found totally -- great minds always think alike :) This patch fixes all the similar typos. Thanks for Randy's ack and comments. Signed-off-by: Coly Li <coyli@suse.de> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Roland Dreier <rolandd@cisco.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Jeff Garzik <jeff@garzik.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Vlad Yasevich <vladislav.yasevich@hp.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* UBI: fix and re-work debugging stuffArtem Bityutskiy2008-07-241-10/+10
| | | | Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: add ubi_sync() interfaceArtem Bityutskiy2008-07-241-0/+24
| | | | | | To flush MTD device caches. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: avoid unnecessary division operationsKyungmin Park2008-07-241-3/+3
| | | | | | | | UBI already checks that @min io size is the power of 2 at io_init. It is save to use bit operations then. Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: fix warningsArtem Bityutskiy2008-01-251-6/+4
| | | | | | | | | | | | | | drivers/mtd/ubi/cdev.c: In function ‘vol_cdev_read’: drivers/mtd/ubi/cdev.c:187: warning: unused variable ‘vol_id’ CC [M] drivers/mtd/ubi/kapi.o drivers/mtd/ubi/kapi.c: In function ‘ubi_leb_erase’: drivers/mtd/ubi/kapi.c:483: warning: unused variable ‘vol_id’ drivers/mtd/ubi/kapi.c: In function ‘ubi_leb_unmap’: drivers/mtd/ubi/kapi.c:544: warning: unused variable ‘vol_id’ drivers/mtd/ubi/kapi.c: In function ‘ubi_leb_map’: drivers/mtd/ubi/kapi.c:582: warning: unused variable ‘vol_id’ Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: use separate mutex for volumes checkingArtem Bityutskiy2007-12-261-8/+3
| | | | | | | | | 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>
* UBI: add UBI devices reference countingArtem Bityutskiy2007-12-261-18/+41
| | | | | | | | | | 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>
* UBI: introduce volume refcountingArtem Bityutskiy2007-12-261-1/+3
| | | | | | | | 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>
* UBI: fix and cleanup volume opening functionsArtem Bityutskiy2007-12-261-36/+25
| | | | | | | | This patch fixes error codes of the functions - if the device number is out of range, -EINVAL should be returned. It also removes unneeded try_module_get call from the open by name function. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: get device when opening volumeArtem Bityutskiy2007-12-261-0/+2
| | | | | | | | When a volume is opened, get its kref via get_device() call. And put the reference when closing the volume. With this, we may have a bit saner volume delete. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: tweak volumes lockingArtem Bityutskiy2007-12-261-5/+6
| | | | | | | Transform vtbl_mutex to volumes_mutex - this just makes code easier to understand. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: improve internal interfacesArtem Bityutskiy2007-12-261-6/+6
| | | | | | | | 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>
* UBI: remove redundant fieldArtem Bityutskiy2007-12-261-2/+2
| | | | | | | Remove redundant ubi->major field - we have it in ubi->cdev.dev already. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: add ubi_leb_map interfaceArtem Bityutskiy2007-12-261-0/+45
| | | | | | | | | | | | | | The idea of this interface belongs to Adrian Hunter. The interface is extremely useful when one has to have a guarantee that an LEB will contain all 0xFFs even in case of an unclean reboot. UBI does have an 'ubi_leb_erase()' call which may do this, but it is stupid and ineffecient, because it flushes whole queue. I should be re-worked to just be a pair of unmap, map calls. The user of the interfaci is UBIFS at the moment. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: don't use array index before testing if it is negativeJesper Juhl2007-10-141-2/+7
| | | | | | | | | | | | | I can't find anything guaranteeing that 'ubi_num' cannot be <0 in drivers/mtd/ubi/kapi.c::ubi_open_volume(), and in fact the code even tests for that and errors out if so. Unfortunately the test for "ubi_num < 0" happens after we've already used 'ubi_num' as an array index - bad thing to do if it is negative. This patch moves the test earlier in the function and then moves the indexing using that variable after the check. A bit safer :-) Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: remove unneeded error checksArtem Bityutskiy2007-07-181-2/+1
| | | | | | Pointed to by viro. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: cleanup usage of try_module_getFernando Luis Vázquez Cao2007-07-181-5/+0
| | | | | | | | | | | | The use of try_module_get(THIS_MODULE) in ubi_get_device_info does not offer real protection against unexpected driver unloads, since we could be preempted before try_modules_get gets executed. It is the caller who should manipulate the refcounts. Besides, ubi_get_device_info is an exported symbol which guarantees protection when accessed through symbol_get. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: do not let to read too muchArtem Bityutskiy2007-07-181-3/+8
| | | | | | | In case of static volumes it is prohibited to read more data then available. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: Unsorted Block ImagesArtem B. Bityutskiy2007-04-271-0/+575
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>