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* UBI: extend UBI layer debug/messaging capabilities - cosmeticsTanya Brokhman2015-01-281-8/+2
| | | | | | | | Some cosmetic fixes to the patch "UBI: Extend UBI layer debug/messaging capabilities". Signed-off-by: Tanya Brokhman <tlinder@codeaurora.org> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Fix double free after do_sync_erase()Richard Weinberger2014-11-071-7/+3
| | | | | | | | | | | If the erase worker is unable to erase a PEB it will free the ubi_wl_entry itself. The failing ubi_wl_entry must not free()'d again after do_sync_erase() returns. Cc: <stable@vger.kernel.org> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Extend UBI layer debug/messaging capabilitiesTanya Brokhman2014-11-071-31/+39
| | | | | | | | | | | | | | If there is more then one UBI device mounted, there is no way to distinguish between messages from different UBI devices. Add device number to all ubi layer message types. The R/O block driver messages were replaced by pr_* since ubi_device structure is not used by it. Amended a bit by Artem. Signed-off-by: Tanya Brokhman <tlinder@codeaurora.org> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Fix trivial typo in __schedule_ubi_workRichard Weinberger2014-09-301-1/+1
| | | | | | | s/of/if/ Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: wl: Rename cancel flag to shutdownRichard Weinberger2014-09-261-11/+13
| | | | | | | | | | | | It confused me more than once that the cancel flag of the work function does not indicate the cancellation of a single work. In fact it indicates the WL sub-system shutdown and therefore worker functions have to free their wl_entries too. That's why you cannot cancel a single work, you can only shutdown all works. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Fix livelock in produce_free_peb()Richard Weinberger2014-09-241-1/+1
| | | | | | | | | | | | The while loop in produce_free_peb() assumes that each work will produce a free PEB. This is not true. If ubi->works_count is 1 and the only scheduled work is the wear_leveling_worker() produce_free_peb() can loop forever in case nobody schedules an erase work. Fix this issue by checking in the while loop whether work is scheduled. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: bugfix in ubi_wl_flush()Richard Weinberger2014-07-281-2/+2
| | | | | | | | Use the _safe variant because we're iterating over a list where items get deleted and freed. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: fix ubi free PEBs count calculationTanya Brokhman2014-05-051-0/+3
| | | | | | | | | | The ubi->free_count should be updated with every insert/remove to/from the ubi->free list. Signed-off-by: Tanya Brokhman <tlinder@codeaurora.org> Reviewed-by: Dolev Raviv <draviv@codeaurora.org> Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: fix error path in __wl_get_pebTanya Brokhman2014-05-051-0/+3
| | | | | | | | | | | In case of an error (if there are not free PEB's for example), __wl_get_peb will return a negative value. In order to prevent access violation we need to test the returned value prior to using it later on. Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org> Reviewed-by: Dolev Raviv <draviv@codeaurora.org> Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: fix refill_wl_user_pool()Richard Weinberger2013-10-031-4/+0
| | | | | | | | | | If no free PEBs are available refill_wl_user_pool() must not return with -ENOSPC immediately. It has to block till produce_free_peb() produced a free PEB. Reported-and-Tested-by: Richard Genoud <richard.genoud@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Fix PEB leak in wear_leveling_worker()Richard Weinberger2013-08-191-0/+3
| | | | | | | | | | | | | | get_peb_for_wl() removes the PEB from the free list. If the WL subsystem detects that no wear leveling is needed it cancels the operation and drops the gained PEB. In this case we have to put the PEB back into the free list. This issue was introduced with commit ed4b7021c (UBI: remove PEB from free tree in get_peb_for_wl()). Cc: <stable@vger.kernel.org> # 3.7.x Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* Merge tag 'upstream-3.8-rc1' of git://git.infradead.org/linux-ubiLinus Torvalds2012-12-201-4/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull UBI update from Artem Bityutskiy: "Nothing exciting, just clean-ups and nicification. Oh, and one small optimization which makes UBI to use less RAM." * tag 'upstream-3.8-rc1' of git://git.infradead.org/linux-ubi: UBI: embed ubi_debug_info field in ubi_device struct UBI: introduce helpers dbg_chk_{io, gen} UBI: replace memcpy with struct assignment UBI: remove spurious comment UBI: gluebi: rename misleading variables UBI: do not allocate the memory unnecessarily UBI: use list_move_tail instead of list_del/list_add_tail
| * UBI: introduce helpers dbg_chk_{io, gen}Ezequiel Garcia2012-12-101-3/+3
| | | | | | | | | | | | | | | | | | | | With this patch code is a bit more readable and there's no generated code or functionality impact. Furthermore, this abstracts implementation details and will allow to change ubi_debug_info in a less invasive way. Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
| * UBI: remove spurious commentEzequiel Garcia2012-11-301-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This line of comment looks completely bogus. It was introduced in: commit d99383b00eba9c6ac3dea462d718b2849012ee03 Author: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Date: Wed May 18 14:47:34 2011 +0300 UBI: change the interface of a debugging check function Remove it. Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* | UBI: dont call ubi_self_check_all_ff() in __wl_get_peb()Richard Weinberger2012-12-041-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | As ubi_self_check_all_ff() might sleep we are not allowed to call it from atomic context. For now we call it only from ubi_wl_get_peb(). There are some code paths where it would also make sense, but these paths are currently atomic and only enabled when fastmap is used. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* | UBI: remove PEB from free tree in get_peb_for_wl()Richard Weinberger2012-12-041-1/+7
|/ | | | | | | | | | If UBI is built without fastmap, get_peb_for_wl() has to remove the PEB manially from the free tree. Otherwise the requested PEB lives in two trees. Reported-by: Zach Sadecki <zsadecki@itwatchdogs.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Add fastmap support to the WL sub-systemRichard Weinberger2012-10-031-44/+531
| | | | | | | | | To make fastmap possible the WL sub-system needs some changes. Mostly to support fastmaps pools. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Add fastmap stuff to ubi.hRichard Weinberger2012-10-031-24/+0
| | | | | | | | | This patch adds fastmap specific data structures to ubi.h. It moves also struct ubi_work to ubi.h as it is now needed for more than one c file. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: print lessArtem Bityutskiy2012-09-041-1/+1
| | | | | | | | | | | UBI currently prints a lot of information when it mounts a volume, which bothers some people. Make it less chatty - print only important information by default. Get rid of 'dbg_msg()' macro completely. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: limit amount of reserved eraseblocks for bad PEB handlingShmulik Ladkani2012-09-041-17/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing mechanism of reserving PEBs for bad PEB handling has two flaws: - It is calculated as a percentage of good PEBs instead of total PEBs. - There's no limit on the amount of PEBs UBI reserves for future bad eraseblock handling. This patch changes the mechanism to overcome these flaws. The desired level of PEBs reserved for bad PEB handling (beb_rsvd_level) is set to the maximum expected bad eraseblocks (bad_peb_limit) minus the existing number of bad eraseblocks (bad_peb_count). The actual amount of PEBs reserved for bad PEB handling is usually set to the desired level (but in some circumstances may be lower than the desired level, e.g. when attaching to a device that has too few available PEBs to satisfy the desired level). In the case where the device has too many bad PEBs (above the expected limit), then the desired level, and the actual amount of PEBs reserved are set to zero. No PEBs will be set aside for future bad eraseblock handling - even if some PEBs are made available (e.g. by shrinking a volume). If another PEB goes bad, and there are available PEBs, then the eraseblock will be marked bad (consuming one available PEB). But if there are no available PEBs, ubi will go into readonly mode. Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
* UBI: correct ubi_wl_flush lockingArtem Bityutskiy2012-06-071-4/+13
| | | | | | | | | | | Commit "62f38455 UBI: modify ubi_wl_flush function to clear work queue for a lnum" takes the 'work_sem' semaphore in write mode for the entire loop, which is not very good because it will block other workers for potentially long time. We do not need to have it in write mode - read mode is enough, and we do not need to hole it over the entire loop. So this patch turns changes the locking: takes 'work_sem' in read mode and pushes it down to the loop. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: modify ubi_wl_flush function to clear work queue for a lnumJoel Reardon2012-05-211-25/+36
| | | | | | | | | | | | | | | | | | | | | | | | | This patch modifies ubi_wl_flush to force the erasure of particular volume id / logical eraseblock number pairs. Previous functionality is preserved when passing UBI_ALL for both values. The locations where ubi_wl_flush were called are appropriately changed: ubi_leb_erase only flushes for the erased LEB, and ubi_create_volume forces only flushing for its volume id. External code can call this new feature via the new function ubi_flush() added to kapi.c, which simply passes through to ubi_wl_flush(). This was tested by disabling the call to do_work in ubi thread, which results in the work queue remaining unless explicitly called to remove. UBIFS was changed to call ubifs_leb_change 50 times for four different LEBs. Then the new function was called to clear the queue: passing wrong volume ids / lnum, correct ones, and finally UBI_ALL for both to ensure it was finally all cleard. The work queue was dumped each time and the selective removal of the particular LEB numbers was observed. Extra checks were enabled and ubifs's integck was also run. Finally, the drive was repeatedly filled and emptied to ensure that the queue was cleared normally. Artem: amended the patch. Signed-off-by: Joel Reardon <reardonj@inf.ethz.ch> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: add lnum and vol_id to struct ubi_workJoel Reardon2012-05-211-9/+23
| | | | | | | | | | | | | | | | | | | | | This is part of a multipart patch to allow UBI to force the erasure of particular logical eraseblock numbers. In this patch, the volume id and LEB number are added to ubi_work data structure, and both are also passed as a parameter to schedule erase to set it appropriately. Whenever ubi_wl_put_peb is called, the lnum is also passed to be forwarded to schedule erase. Later, a new ubi_sync_lnum will be added to execute immediately all work related to that lnum. This was tested by outputting the vol_id and lnum during the schedule of erasure. The ubi thread was disabled and two ubifs drives on separate partitions repeated changed a small number of LEBs. The ubi module was readded, and all the erased LEBs, corresponding to the volumes, were added to the schedule erase queue. Artem: minor tweaks Signed-off-by: Joel Reardon <reardonj@inf.ethz.ch> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: rename _init_scan functionsArtem Bityutskiy2012-05-201-2/+2
| | | | | | | | | | We have a couple of initialization funcntionsn left which have "_scan" suffic - rename them: ubi_eba_init_scan() -> ubi_eba_init() ubi_wl_init_scan() -> ubi_wl_init() Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: rename sv to avArtem Bityutskiy2012-05-201-3/+3
| | | | | | | | | After re-naming the 'struct ubi_scan_volume' we should adjust all variables named 'sv' to something else, because 'sv' stands for "scanning volume". Let's rename it to 'av' which stands for "attaching volume" which is a bit more consistent and has the same length, which makes re-naming easy. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
* UBI: rename si to aiArtem Bityutskiy2012-05-201-7/+7
| | | | | | | | | After re-naming the 'struct ubi_scan_info' we should adjust all variables named 'si' to something else, because 'si' stands for "scanning info". Let's rename it to 'ai' which stands for "attaching info" which is a bit more consistent and has the same length, which makes re-naming easy. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
* UBI: rename seb to aebArtem Bityutskiy2012-05-201-11/+11
| | | | | | | | | After re-naming the 'struct ubi_scan_leb' we should adjust all variables named 'seb' to something else, because 'seb' stands for "scanning eraseblock". Let's rename it to 'aeb' which stands for "attaching eraseblock" which is a bit more consistend and has the same length. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
* UBI: rename struct ubi_scan_infoArtem Bityutskiy2012-05-201-1/+1
| | | | | | | | | | Rename 'struct ubi_scan_info' to 'struct ubi_attach_info'. This is part of the code re-structuring I am trying to do in order to add fastmap in a more logical way. Fastmap can share a lot with scanning, including the attach-time data structures, which all now have "scan" word in the name. Let's get rid of this word. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
* UBI: rename struct ubi_scan_volumeArtem Bityutskiy2012-05-201-1/+1
| | | | | | | | | | | | Rename 'struct ubi_scan_volume' to 'struct ubi_ainf_volume'. This is part of the code re-structuring I am trying to do in order to add fastmap in a more logical way. Fastmap can share a lot with scanning, including the attach-time data structures, which all now have "scan" word in the name. Let's get rid of this word and use "ainf" instead which stands for "attach information". It has the same length as "scan" so re-naming is trivial. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
* UBI: rename struct ubi_scan_lebArtem Bityutskiy2012-05-201-1/+1
| | | | | | | | | | | | Rename 'struct ubi_scan_leb' to 'struct ubi_ainf_leb'. This is part of the code re-structuring I am trying to do in order to add fastmap in a more logical way. Fastmap can share a lot with scanning, including the attach-time data structures, which all now have "scan" word in the name. Let's get rid of this word and use "ainf" instead which stands for "attach information". It has the same length as "scan" so re-naming is trivial. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
* UBI: rename few functions for consistencyArtem Bityutskiy2012-05-201-2/+2
| | | | Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: more of clean-up terminology for self-checksArtem Bityutskiy2012-05-201-28/+26
| | | | | | | | | | | We have the "sefl-check" feature in UBI, but for historical reasons many corresponding functions and commentaries in the code use term "paranoid check" instead. Let's clean this up and use "self-check" everywhere. This patch renames functions, amends messages and kills several redundant debugging messages. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: remove Kconfig debugging optionArtem Bityutskiy2012-05-201-10/+0
| | | | | | | | | This patch kills the UBI debugging Kconfig option completely and makes all the debugging stuff to be always compiled-in. It was pain in the neck to maintain this useless option because all users I am aware of have debugging enabled anyway - how else will you diagnose errors otherwise? Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: amend commentaries WRT dtypeArtem Bityutskiy2012-05-201-8/+1
| | | | | | | | | | | Richard removed the "dtype" hint, but few commentaries were left and this patch removes them. I've also added a better description about the "dtype" field in the ubi-user.h for people who may ever wonder what was that dtype thing about. This patch also adds an important note that it is better to use value "3" for the "dtype" field. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: Kill data type hintRichard Weinberger2012-05-201-42/+8
| | | | | | | | | | | We do not need this feature and to our shame it even was not working and there was a bug found very recently. -- Artem Bityutskiy Without the data type hint UBI2 (fastmap) will be easier to implement. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: always dump the stack on errorArtem Bityutskiy2012-05-201-3/+3
| | | | | | | | | | | | UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to link as few as possible when debugging is disabled, but the downside is that most people produce bug reports which are difficult to understand. This patch weeds out the 'ubi_dbg_dump_stack()' function and turns it into 'dump_stack()' - it is always useful to have stack dump in case of an error. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
* UBI: rename MOVE_CANCEL_BITFLIPS to MOVE_TARGET_BITFLIPSArtem Bityutskiy2012-03-091-1/+1
| | | | | | | | While looking at a problem reported by UBI around the PEB moving area I noticed that the 'MOVE_CANCEL_BITFLIPS' is a bit inconsistent name and 'MOVE_TARGET_BITFLIPS' better - let's rename it. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: fix eraseblock picking criteriaArtem Bityutskiy2012-03-091-6/+4
| | | | | | | | | | | The 'find_wl_entry()' function expects the maximum difference as the second argument, not the maximum absolute value. So the "unknown" eraseblock picking was incorrect, as Shmulik Ladkani spotted. This patch fixes the issue. Reported-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Cc: stable@kernel.org
* UBI: fix documentation and improve readabilityArtem Bityutskiy2012-03-091-4/+5
| | | | | | | | | | The "max" parameter of 'find_wl_entry()' was documented incorrectly and it actually means the maximum possible difference from the smallest erase counter. Rename it to "diff" instead, and amend the documentation. Reported-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
* UBI: fix use-after-free on error pathArtem Bityutskiy2012-01-051-3/+4
| | | | | | | | | | When we fail to erase a PEB, we free the corresponding erase entry object, but then re-schedule this object if the error code was something like -EAGAIN. Obviously, it is a bug to use the object after we have freed it. Reported-by: Emese Revfy <re.emese@gmail.com> Cc: stable@kernel.org [v2.6.23+] Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: fix missing scrub when there is a bit-flipBhavesh Parekh2011-11-301-1/+4
| | | | | | | | | | | Under some cases, when scrubbing the PEB if we did not get the lock on the PEB it fails to scrub. Add that PEB again to the scrub list Artem: minor amendments. Cc: stable@kernel.org [2.6.31+] Signed-off-by: Bhavesh Parekh <bparekh@nvidia.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* UBI: prepare debugging stuff to further debugfs conversionArtem Bityutskiy2011-06-011-2/+2
| | | | | | | | We'll need the 'struct ubi_device *ubi' pointer in every debugging function (to access the ->dbg field), so add this pointer to all the functions implementing UBI debugging test modes like 'ubi_dbg_is_bitflip()' etc. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: use debugfs for the extra checks knobsArtem Bityutskiy2011-06-011-3/+3
| | | | | | | | | | This patch introduces debugfs support to UBI. All the UBI stuff is kept in the "ubi" debugfs directory, which contains per-UBI device "ubi/ubiX" sub-directories, containing debugging files. This file also creates "ubi/ubiX/chk_gen" and "ubi/ubiX/chk_io" knobs for switching general and I/O extra checks on and off. And it removes the 'debug_chks' UBI module parameters. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: change the interface of a debugging check functionArtem Bityutskiy2011-05-311-13/+19
| | | | | | | | | | | This is a minor preparational patch which changes the 'paranoid_check_in_wl_tree()' function interface by adding the 'ubi' parameter which will be needed there in the next patch. And while on it, add "const" qualifier to the 'ubi' parameter of the 'paranoid_check_in_pq()' function. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: fix minor stylistic issuesArtem Bityutskiy2011-04-141-1/+2
| | | | | | | | | | Fix checkpatch.pl errors and warnings: * space before tab * line over 80 characters * include linux/ioctl.h instead of asm/ioctl.h Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: make tests modes dynamicArtem Bityutskiy2011-03-161-2/+2
| | | | | | | | | | | | Similarly to the debugging checks and message, make the test modes be dynamically selected via the "debug_tsts" module parameter or via the "/sys/module/ubi/parameters/debug_tsts" sysfs file. This is consistent with UBIFS as well. And now, since all the Kconfig knobs became dynamic, we can remove the Kconfig.debug file completely. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: make self-checks dynamicArtem Bityutskiy2011-03-161-3/+13
| | | | | | | | | | | | | | This patch adds a possibility to dynamically switch UBI self-checks on and off, instead of toggling them compile-time from the configuration menu. This is much more flexible, and consistent with UBIFS, and this also simplifies UBI Kconfig menu and the code. This patch introduces two levels of self-checks - general, which includes all self-checks which are relatively fast, and I/O, which includes write-verify checks and erase-verify checks, which are relatively slow and involve flash I/O. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBI: preserve corrupted PEBsArtem Bityutskiy2010-10-191-16/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* UBI: handle bit-flips when no header foundArtem Bityutskiy2010-10-191-0/+10
| | | | | | | | | | | | | | 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>
* UBI: remove duplicate IO error codesArtem Bityutskiy2010-10-191-1/+1
| | | | | | | | | | | 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>
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