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path: root/drivers/mtd/ubi/ubi.h
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2010-10-19UBI: preserve corrupted PEBsArtem Bityutskiy
Currently UBI erases all corrupted eraseblocks, irrespectively of the nature of corruption: corruption due to power cuts and non-power cut corruption. The former case is OK, but the latter is not, because UBI may destroy potentially important data. With this patch, during scanning, when UBI hits a PEB with corrupted VID header, it checks whether this PEB contains only 0xFF data. If yes, it is safe to erase this PEB and it is put to the 'erase' list. If not, this may be important data and it is better to avoid erasing this PEB. Instead, UBI puts it to the corr list and moves out of the pool of available PEB. IOW, UBI preserves this PEB. Such corrupted PEB lessen the amount of available PEBs. So the more of them we accumulate, the less PEBs are available. The maximum amount of non-power cut corrupted PEBs is 8. This patch is a response to UBIFS problem where reporter (Matthew L. Creech <mlcreech@gmail.com>) observes that UBIFS index points to an unmapped LEB. The theory is that corresponding PEB somehow got corrupted and UBI wiped it. This patch (actually a series of patches) tries to make sure such PEBs are preserved - this would make it is easier to analyze the corruption. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-19UBI: make check_pattern function non-staticArtem Bityutskiy
This patch turns static function 'check_pattern()' into a non-static 'ubi_check_pattern()'. This is just a preparation for the chages which are coming in the next patches. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-19UBI: handle bit-flips when no header foundArtem Bityutskiy
Currently UBI has one small flaw - when we read EC or VID header, but find only 0xFF bytes, we return UBI_IO_FF and do not report whether we had bit-flips or not. In case of the VID header, the scanning code adds this PEB to the free list, even though there were bit-flips. Imagine the following situation: we start writing VID header to a PEB and have a power cut, so the PEB becomes unstable. When we scan and read the PEB, we get a bit-flip. Currently, UBI would just ignore this and treat the PEB as free. This patch changes UBI behavior and now UBI will schedule this PEB for erasure. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-19UBI: remove duplicate IO error codesArtem Bityutskiy
The 'UBI_IO_PEB_EMPTY' and 'UBI_IO_PEB_FREE' are essentially the same and mean that there are only 0xFF bytes instead of headers. Simplify UBI a little by turning them into a single 'UBI_IO_FF' error code. Also, stop maintaining commentaries in 'ubi_io_read_vid_hdr()' which are almost identical to commentaries in 'ubi_io_read_ec_hdr()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-10-19UBI: rename IO error codeArtem Bityutskiy
Rename UBI_IO_BAD_HDR_READ into UBI_IO_BAD_HDR_EBADMSG which is presumably more self-documenting and readable. Indeed, the '_READ' suffix does not tell much and even confuses, while '_EBADMSG' tells about uncorrectable ECC error, because we use -EBADMSG all over the place to represent ECC errors. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-06-04UBI: introduce a new IO return codeArtem Bityutskiy
This patch introduces the %UBI_IO_BAD_HDR_READ return code for the I/O level function. We will use this code in order to distinguish between "corrupted header possibly because this is non-ubi data" and "corrupted header possibly because of real data corruption and ECC error". So far this patch does not introduce any functional change, just a preparation. This patch is pased on a patch from Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Reviewed-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Tested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
2010-06-04UBI: simplify IO error codesArtem Bityutskiy
We do not really need 2 separate error codes for indicating bad VID and bad EC headers (UBI_IO_BAD_EC_HDR, UBI_IO_BAD_VID_HDR), it is enough to have only one UBI_IO_BAD_HDR return code. This patch does not introduce any functional change, only some code simplification. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Reviewed-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Tested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
2010-05-03UBI: remove reboot notifierKevin Cernekee
The UBI reboot notifier causes problems with hibernation. Move this functionality into the low-level MTD driver instead. Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
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>
2009-09-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits) trivial: fix typo in aic7xxx comment trivial: fix comment typo in drivers/ata/pata_hpt37x.c trivial: typo in kernel-parameters.txt trivial: fix typo in tracing documentation trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c trivial: remove unnecessary semicolons trivial: Fix duplicated word "options" in comment trivial: kbuild: remove extraneous blank line after declaration of usage() trivial: improve help text for mm debug config options trivial: doc: hpfall: accept disk device to unload as argument trivial: doc: hpfall: reduce risk that hpfall can do harm trivial: SubmittingPatches: Fix reference to renumbered step trivial: fix typos "man[ae]g?ment" -> "management" trivial: media/video/cx88: add __init/__exit macros to cx88 drivers trivial: fix typo in CONFIG_DEBUG_FS in gcov doc trivial: fix missing printk space in amd_k7_smp_check trivial: fix typo s/ketymap/keymap/ in comment trivial: fix typo "to to" in multiple files trivial: fix typos in comments s/DGBU/DBGU/ ...
2009-09-21trivial: fix typo "to to" in multiple filesAnand Gadiyar
Signed-off-by: Anand Gadiyar <gadiyar@ti.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-08-14UBI: eliminate possible undefined behaviourPhil Carmody
The assignment to pos when rb is finally NULL is undefined behaviour. Upon seeing that assignment, GCC may assume that rb is not NULL, and the loop condition ``rb'' may be optimised away. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-07UBI: fix NOR flash recoveryArtem Bityutskiy
This commit fixes NOR flash recovery issues observed with Spansion S29GL512N NOR. When NOR erases, it first fills PEBs with zeroes, then sets all bytes to 0xFF. Filling with zeroes starts from the end of the PEB. And when power is cut, this results in PEBs containing correct EC and VID headers but corrupted with zeros at the end. This confuses UBI and it mistakinly accepts these PEBs and associate them with LEBs. Fis this issue by zeroing EC and VID magics before erasing PEBs, to make UBI later refuse zem. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-05UBI: nicify image sequence number handlingArtem Bityutskiy
Move the image seq. number handling from I/O level to the scanning lever, where it really belongs to. Move the @image_seq_set variable to the @struct ubi_scan_info structure, which exists only during scanning. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-05UBI: add image sequence number to EC headerAdrian Hunter
An image sequence number is added to the UBI erase-counter header to be able determine if the root file system contains a mixture of old and new images (because the flashing failed to complete). A change to nolo is also needed for this to take effect. Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-10UBI: add reboot notifierKevin Cernekee
Terminate the UBI background thread prior to restarting the system. [Artem: amended comments a little] Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com> Tested-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-10UBI: fix multiple spelling typosArtem Bityutskiy
Some of the typos were indicated by Adrian Hunter, some by 'aspell'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02UBI: remove built-in gluebiDmitry Pervushin
Remove built-in gluebi support. This is a preparation for a standalone glubi module support Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02UBI: add notification APIDmitry Pervushin
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>
2009-06-02UBI: do not switch to R/O mode on read errorsArtem Bityutskiy
This patch improves UBI errors handling. ATM UBI switches to R/O mode when the WL worker fails to read the source PEB. This means that the upper layers (e.g., UBIFS) has no chances to unmap the erroneous PEB and fix the error. This patch changes this behaviour and makes UBI put PEBs like this into a separate RB-tree, thus preventing the WL worker from hitting the same read errors again and again. But there is a 10% limit on a maximum amount of PEBs like this. If there are too much of them, UBI switches to R/O mode. Additionally, this patch teaches UBI not to panic and switch to R/O mode if after a PEB has been copied, the target LEB cannot be read back. Instead, now UBI cancels the operation and schedules the target PEB for torturing. The error paths has been tested by ingecting errors into 'ubi_eba_copy_leb()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02UBI: introduce new constantsArtem Bityutskiy
This patch is a clean-up and a preparation for the following patches. It introduece constants for the return values of the 'ubi_eba_copy_leb()' function. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18UBI: small debugging code optimizationArtem Bityutskiy
The @ubi->dbg_peb_buf is needed only when paranoid checks are enabled, not when debugging in general is enabled. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18UBI: re-name volumes_mutex to device_mutexArtem Bityutskiy
The mutex essencially protects the entire UBI device, so the old @volumes_mutex name is a little misleading. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18UBI: remove redundant mutexArtem Bityutskiy
The @mult_mutex does not serve any purpose. We already have @volumes_mutex and it is enough. The @volume mutex is pushed down to the 'ubi_rename_volumes()', because we want first to open all volumes in the exclusive mode, and then lock the mutex, just like all other ioctl's (remove, re-size, etc) do. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-01-27UBI: allow direct user-space I/OSidney Amani
Introduce a new ioctl UBI_IOCSETPROP to set properties on a volume. Also add the first property: UBI_PROP_DIRECT_WRITE, this property is used to set the ability to use direct writes in userspace Signed-off-by: Sidney Amani <seed@uffs.org> Signed-off-by: Corentin Chary <corentincj@iksaif.net> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-01-18UBI: constify file operationsJan Engelhardt
Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-12-16UBI: simplify PEB protection codeXiaochuan-Xu
UBI has 2 RB-trees to implement PEB protection, which is too much for simply prevent PEB from being moved for some time. This patch implements this using lists. The benefits: 1. No need to allocate protection entry on each PEB get. 2. No need to maintain balanced trees and walk them. Signed-off-by: Xiaochuan-Xu <xiaochuan-xu@cqu.edu.cn> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-12-15UBI: prepare for protection tree improvementsXiaochuan-Xu
This patch modifies @struct ubi_wl_entry and adds union which contains only one element so far. This is just a preparation for further changes which will kill the protection tree and make UBI use a list instead. Signed-off-by: Xiaochuan-Xu <xiaochuan-xu@cqu.edu.cn> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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>