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* UBIFS: add a superblock flag for free space fix-upMatthew L. Creech2011-05-16
| | | | | | | | | | | | | | | The 'space_fixup' flag can be set in the superblock of a new filesystem by mkfs.ubifs to indicate that any eraseblocks with free space remaining should be fixed-up the first time it's mounted (after which the flag is un-set). This means that the UBIFS image has been flashed by a "dumb" flasher and the free space has been actually programmed (writing all 0xFFs), so this free space cannot be used. UBIFS fixes the free space up by re-writing the contents of all LEBs with free space using the atomic LEB change UBI operation. Artem: improved commit message, add some more commentaries to the code. Signed-off-by: Matthew L. Creech <mlcreech@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: share the next_log_lnum helperArtem Bityutskiy2011-05-16
| | | | | | | | We'll need to use the 'next_log_lnum()' helper function from log.c in the fixup code, so let's move it to misc.h. IOW, this is a preparation to the following free space fixup changes. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: expect corruption only in last journal head LEBsArtem Bityutskiy2011-05-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch improves UBIFS recovery and teaches it to expect corruption only in the last buds. Indeed, currently we just recover all buds, which is incorrect because only the last buds can have corruptions in case of a power cut. So it is inconsistent with the rest of the recovery strategy which tries hard to distinguish between corruptions cause by power cuts and other types of corruptions. This patch also adds one quirk - a bit older UBIFS was could have corruption in the next to last bud because of the way it switched buds: when bud A is full, it first searched for the next bud B, the wrote a reference node to the log about B, and then synchronized the write-buffer of A. So we could end up with buds A and B, where B is the last, but A had corruption. The UBIFS behavior was fixed, though, so currently it always first synchronizes A's write-buffer and only after this adds B to the log. However, to be make sure that we handle unclean (after a power cut) UBIFS images belonging to older UBIFS - we need to add a quirk and keep it for some time: we need to check for the situation described above. Thankfully, it is easy to check for that situation. When UBIFS adds B to the log, it always first unmaps B, then maps it, and then syncs A's write-buffer. Thus, in that situation we can check that B is empty, in which case it is OK to have corruption in A. To check that B is empty it is enough to just read the first few bytes of the bud and compare them with 0xFFs. This quirk may be removed in a couple of years. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: synchronize write-buffer before switching to the next budArtem Bityutskiy2011-05-16
| | | | | | | | | | | | | | | | Currently when UBIFS fills up the current bud (which is the last in the journal head) and switches to the next bud, it first writes the log reference node for the next bud and only after this synchronizes the write-buffer of the previous bud. This is not a big deal, but an unclean power cut may lead to a situation when we have corruption in a next-to-last bud, although it is much more logical that we have to have corruption only in the last bud. This patch also removes write-buffer synchronization from 'ubifs_wbuf_seek_nolock()' because this is not needed anymore (we synchronize the write-buffer explicitly everywhere now) and also because this is just prone to various errors. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: remove BUG statementArtem Bityutskiy2011-05-16
| | | | | | | Remove a 'BUG()' statement when we are unable to find a bud and add a similar 'ubifs_assert()' statement instead. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: change bud replay function conventionsArtem Bityutskiy2011-05-16
| | | | | | | | | This is a minor preparation patch which changes 'replay_bud()' interface - instead of passing bud lnum, offs, jhead, etc directly, pass a pointer to the bud entry which contains all the information. The bud entry will be also needed in one of the following patches. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: substitute the replay tree with a replay listArtem Bityutskiy2011-05-16
| | | | | | | | | | | This patch simplifies replay even further - it removes the replay tree and adds the replay list instead. Indeed, we just do not need to use a tree here - all we need to do is to add all nodes to the list and then sort it. Using RB-tree is an overkill - more code and slower. And since we replay buds in order, we expect the nodes to follow in _mostly_ sorted order, so the merge sort becomes much cheaper in average than an RB-tree. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: simplify replayArtem Bityutskiy2011-05-16
| | | | | | | | | | | | | | | This patch simplifies the replay code and makes it smaller. First of all, we can notice that we do not really need to create bud replay entries and insert them to the replay tree, because the only reason we do this is to set buds lprops correctly at the end. Instead, we can just walk the list of buds at the very end and set lprops for each bud. This allows us to get rid of whole 'insert_ref_node()' function, the 'REPLAY_REF' flag, and several fields in 'struct replay_entry'. Then we can also notice that we do not need the 'flags' 'struct replay_entry' field, because there is only one flag - 'REPLAY_DELETION'. Instead, we can just add a 'deletion' bit fields. As a result, this patch deletes much more lines that in adds. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: store free and dirty space in the bud replay entryArtem Bityutskiy2011-05-16
| | | | | | | This is just a small preparation patch which adds 'free' and 'drity' fields to 'struct bud_entry'. They will be used to set bud lprops. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: remove unnecessary stack variableArtem Bityutskiy2011-05-16
| | | | | | | | | This is patch removes an unnecessary 'offs' variable from 'ubifs_wbuf_write_nolock()' - we can just keep 'wbuf->offs' up-to-date instead. This patch is very minor the only motivation for it was that it is cleaner to keep wbuf->offs up-to-date by the time we call 'ubifs_leb_write()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: double check that buds are replied in orderArtem Bityutskiy2011-05-16
| | | | | | | | | | | Commit 52c6e6f990669deac3f370f1603815adb55a1dbd provides misleading infomation in the commit messages - buds are replied in order. And the real reason why that fix helped is probably because it made sure we seek head even in read-only mode (so deferred recovery will have seeked heads). This patch adds an assertion which will fire if we reply buds out of order. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: make 2 functions staticArtem Bityutskiy2011-05-16
| | | | | | | | This is a minor change which makes 2 functions static because they are not used outside the gc.c file: 'data_nodes_cmp()' and 'nondata_nodes_cmp()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: improve commentaryArtem Bityutskiy2011-05-16
| | | | | | This is a tiny clean-up patch which improves replay commentaries. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: improve debugging messagesArtem Bityutskiy2011-05-16
| | | | | | Print a bit more information is some recovery and replay paths. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: dump more in the lprops debugging checkArtem Bityutskiy2011-05-16
| | | | Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: simplify lprops debugging checkArtem Bityutskiy2011-05-16
| | | | | | | Now we return all errors from 'scan_check_cb()' directly, so we do not need 'struct scan_check_data' any more, and this patch removes it. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: simplify error path in lprops debugging checkArtem Bityutskiy2011-05-16
| | | | | | | Simplify error path in 'scan_check_cb()' and stop using the special 'data->err' field, but instead return the error code directly. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: improve debugging lprops scanning a littleArtem Bityutskiy2011-05-16
| | | | | | | | | When doing the lprops extra check ('dbg_check_lprops()') we scan whole media. We even scan empty and freeable LEBs which may contain garbage, which we handle after scanning. This patch teach the lprops checking function ('scan_check_cb()') to avoid scanning for free and freeable LEBs and save time. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: fix a rare memory leak in ro to rw remounting pathArtem Bityutskiy2011-05-13
| | | | | | | | | | When re-mounting from R/O mode to R/W mode and the LEB count in the superblock is not up-to date, because for the underlying UBI volume became larger, we re-write the superblock. We allocate RAM for these purposes, but never free it. So this is a memory leak, although very rare one. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Cc: stable@kernel.org
* UBIFS: fix inode size debugging check failureArtem Bityutskiy2011-05-13
| | | | | | | | | | | | | | | | This patch fixes a problem with the following symptoms: UBIFS: deferred recovery completed UBIFS error (pid 15676): dbg_check_synced_i_size: ui_size is 11481088, synced_i_size is 11459081, but inode is clean UBIFS error (pid 15676): dbg_check_synced_i_size: i_ino 128, i_mode 0x81a4, i_size 11481088 It happens when additional debugging checks are enabled and we are recovering from a power cut. When we fixup corrupted inode size during recovery, we change them in-place and we change ui_size as well, but not synced_i_size, which causes this failure. This patch makes sure we change both fields and fixes the issue. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: fix debugging FS checking failureArtem Bityutskiy2011-05-13
| | | | | | | | | | | | | | | | | | | | | | | | When the debugging self-checks are enabled, we go trough whole file-system after mount and check/validate every single node referred to by the index. This is implemented by the 'dbg_check_filesystem()' function. However, this function fails if we mount "unclean" file-system, i.e., if we mount the file-system after a power cut. It fails with the following symptoms: UBIFS DBG (pid 8171): ubifs_recover_size: ino 937 size 3309925 -> 3317760 UBIFS: recovery deferred UBIFS error (pid 8171): check_leaf: data node at LEB 1000:0 is not within inode size 3309925 The reason of failure is that recovery fixed up the inode size in memory, but not on the flash so far. So the value on the flash is incorrect so far, and would be corrected when we re-mount R/W. But 'check_leaf()' ignores this fact and tries to validate the size of the on-flash inode, which is incorrect, so it fails. This patch teaches the checking code to look at the VFS inode cache first, and if there is the inode in question, use that inode instead of the inode on the flash media. This fixes the issue. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: remove an unneeded checkArtem Bityutskiy2011-05-13
| | | | | | | | | | | | | In 'ubifs_recover_size()' we have an "if (!e->inode && c->ro_mount)" statement. But if 'c->ro_mount' is true, then '!e->inode' must always be true as well. So we can remove the unnecessary '!e->inode' test and put an 'ubifs_assert(!e->inode)' instead. This patch also removes an extra trailing white-space in a debugging print, as well as adds few empty lines to 'ubifs_recover_size()' to make it a bit more readable. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: fix debugging messageArtem Bityutskiy2011-05-13
| | | | | | | When recovering the inode size, one of the debugging messages was printed incorrecly, this patches fixes it. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: refactor ubifs_rcvry_gc_commitArtem Bityutskiy2011-05-13
| | | | | | | This commits refactors and cleans up 'ubifs_rcvry_gc_commit()' which was quite untidy, also removes the commentary which was not 100% correct. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: split ubifs_rcvry_gc_commitArtem Bityutskiy2011-05-13
| | | | | | | | | | | Split the 'ubifs_rcvry_gc_commit()' function and introduce a 'grab_empty_leb()' heler. This cleans 'ubifs_rcvry_gc_commit()' a little and makes it a bit less of spagetti. Also, add a commentary which explains why it is crucial to first search for an empty LEB and then run commit. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: dump the stack on errors in failure mode tooArtem Bityutskiy2011-05-13
| | | | | | | | | | | | When UBIFS is in the failure mode (used for power cut emulation testing) we for some reasons do not dump the stack in many places, e.g., in assertions. Probably at early days we had too many of them and disabled this to make the development easier, but then never enabled. Nowadays I sometimes observe assertion failures during power cut testing, but the useful stackdump is not printed, which is bad. This patch makes UBIFS always print the stackdump when debugging is enabled. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: print useful debugging messages when cannot recover gc_lnumArtem Bityutskiy2011-05-13
| | | | | | | | If we fail to recover the gc_lnum we just return an error and it then it is difficult to figure out why this happened. This patch adds useful debugging information which should make it easier to debug the failure. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: remove dead GC LEB recovery piece of codeArtem Bityutskiy2011-05-13
| | | | | | | | | | | This patch removes a piece of code in 'ubifs_rcvry_gc_commit()' which is never executed. We call 'ubifs_find_dirty_leb()' function with min_space = wbuf->offs, so if it returns us an LEB, it is guaranteed to have at lease 'wbuf->offs' bytes of free+dirty space. So we can remove the subsequent code which deals with "returned LEB has less than 'wbuf->offs' bytes of free+dirty space". This simplifies 'ubifs_rcvry_gc_commit()' a little. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: remove duplicated codeArtem Bityutskiy2011-05-13
| | | | | | | | | | | | We have duplicated code in 'ubifs_garbage_collect()' and 'ubifs_rcvry_gc_commit()', which is about handling the special case of free LEB. In both cases we just want to garbage-collect the LEB using 'ubifs_garbage_collect_leb()'. This patch teaches 'ubifs_garbage_collect_leb()' to handle free LEB's so that the caller does not have to do this and the duplicated code is removed. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: remove strange commentaryArtem Bityutskiy2011-05-13
| | | | | | | | | | | Remove the following commentary from 'ubifs_file_mmap()': /* 'generic_file_mmap()' takes care of NOMMU case */ I do not understand what it means, and I could not find anything relater to NOMMU in 'generic_file_mmap()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: do not change debugfs file positionArtem Bityutskiy2011-05-13
| | | | | | | | This patch is a tiny improvement which removes few bytes of code. UBIFS debugfs files are non-seekable and the file position is ignored, so do not increase it in the write handler. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: fix oops in lprops dump functionArtem Bityutskiy2011-05-13
| | | | | | | | | | | | The 'dbg_dump_lprop()' is trying to detect journal head LEBs when printing, so it looks at the write-buffers. However, if we are in R/O mode, we de-allocate the write-buffers, so 'dbg_dump_lprop()' oopses. This patch fixes the issue. Note, this patch is not critical, it is only about the debugging code path, and it is unlikely that anyone but UBIFS developers would ever hit this issue. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: use ro_mount instead of MS_RDONLYArtem Bityutskiy2011-05-13
| | | | | | | | | | | We have our own flags indicating R/O mode, and c->ro_mode is equivalent to MS_RDONLY. Let's be consistent and use UBIFS flags everywhere. This patch is just a minor cleanup. Additionally, add a comment that we are surprised with VFS behavior - as a reminder to look at this some day. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: use EROFS when emulating failuresArtem Bityutskiy2011-05-13
| | | | | | | | | | | | | | | When the debugging failure emulation is enabled and UBIFS decides to emulate an I/O error, it uses EIO error code. In which case UBIFS switches into R/O mode later on. The for the user-space is that when a failure is emulated, the file-system sometimes returns EIO and sometimes EROFS. This makes it more difficult to implement user-space tests for the failure mode. Let's be consistent and return EROFS in all the cases. This patch is an improvement for the debugging code and does not affect the functionality at all. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: make xattr operations names consistentSedat Dilek2011-05-13
| | | | | | | | | | | | This is just a tiny clean-up patch. The variable name for empty address space operations is "empty_aops". Let's use consistent names for empty inode and file operations: "empty_iops" and "empty_fops", instead of inconsistent "none_inode_operations" and "none_file_operations". Artem: re-write the commit message. Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: introduce lsave debuggingArtem Bityutskiy2011-05-13
| | | | | | | | | Try to improve UBIFS testing coverage by randomly picking LEBs to store in lsave, rather than picking them optimally. Create a debugging version of 'populate_lsave()' for these purposes and enable it when general debugging self-checks are enabled. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: make force in-the-gaps to be a general self-checkArtem Bityutskiy2011-05-13
| | | | | | | | | | | | UBIFS can force itself to use the 'in-the-gaps' commit method - the last resort method which is normally invoced very very rarely. Currently this "force int-the-gaps" debugging feature is a separate test mode. But it is a bit saner to make it to be the "general" self-test check instead. This patch is just a clean-up which should make the debugging code look a bit nicer and easier to use - we have way too many debugging options. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: improve space checking debugging featureArtem Bityutskiy2011-05-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch improves the 'dbg_check_space_info()' function which checks whether the amount of space before re-mounting and after re-mounting is the same (remounting from R/O to R/W modes and vice-versa). The problem is that 'dbg_check_space_info()' does not save the budgeting information before re-mounting, so when an error is reported, we do not know why the amount of free space changed. This patches makes the following changes: 1. Teaches 'dbg_dump_budg()' function to accept a 'struct ubifs_budg_info' argument and print out the this argument. This way we may ask it to print any saved budgeting info, no only the current one. 2. Accordingly changes all the callers of 'dbg_dump_budg()' to comply with the changed interface. 3. Introduce a 'saved_bi' (saved budgeting info) field to 'struct ubifs_debug_info' and save the budgeting info before re-mounting there. 4. Change 'dbg_check_space_info()' and make it print both old and new budgeting information. 5. Additionally, save 'c->igx_gc_cnt' and print it if and error happens. This value contributes to the amount of free space, so we have to print it. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: rearrange the budget dumpArtem Bityutskiy2011-05-13
| | | | | | | | | | | | Re-arrange the budget dump and make sure we first dump all the 'struct ubifs_budg_info' fields, and then the other information. Additionally, print the 'uncommitted_idx' variable. This change is required for to the following dumping function enhancement where it will be possible to dump saved 'struct ubifs_budg_info' objects, not only the current one. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: simplify dbg_dump_budg calling conventionsArtem Bityutskiy2011-05-13
| | | | | | | | | | | | The current 'dbg_dump_budg()' calling convention is that the 'c->space_lock' spinlock is held. However, none of the callers actually use it from contects which have 'c->space_lock' locked, so all callers have to explicitely lock and unlock the spinlock. This is not very sensible convention. This patch changes it and makes 'dbg_dump_budg()' lock the spinlock instead of imposing this to the callers. This simplifies the code a little. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: introduce a separate structure for budgeting infoArtem Bityutskiy2011-05-13
| | | | | | | | | | | | | This patch separates out all the budgeting-related information from 'struct ubifs_info' to 'struct ubifs_budg_info'. This way the code looks a bit cleaner. However, the main driver for this is that we want to save budgeting information and print it later, so a separate data structure for this is helpful. This patch is a preparation for the further debugging output improvements. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: use __packed instead of __attribute__((packed))Artem Bityutskiy2011-05-13
| | | | | | | | | | | | | | | | | | | There was an attempt to standartize various "__attribute__" and other macros in order to have potentially portable and more consistent code, see commit 82ddcb040570411fc2d421d96b3e69711c670328. Note, that commit refers Rober Love's blog post, but the URL is broken, the valid URL is: http://blog.rlove.org/2005/10/with-little-help-from-your-compiler.html Moreover, nowadays checkpatch.pl warns about using __attribute__((packed)): "WARNING: __packed is preferred over __attribute__((packed))" It is not a big deal for UBIFS to use __packed, so let's do it. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: fix minor stylistic issuesArtem Bityutskiy2011-05-13
| | | | | | | | | Fix several minor stylistic issues: * lines longer than 80 characters * space before closing parenthesis ')' * spaces in the indentations Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: make debugfs files non-seekableArtem Bityutskiy2011-05-13
| | | | | | | | | | | | | Turn the debufs files UBIFS maintains into non-seekable. Indeed, none of them is supposed to be seek'ed. Do this by making the '.lseek()' handler to be 'no_llseek()' and by using 'nonseekable_open()' in the '.open()' operation. This does mean an API break but this debugging API is only used by a couple of test scripts which do not rely in the 'llseek()' operation. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: seek journal heads to the latest bud in replayArtem Bityutskiy2011-05-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the second fix of the following symptom: UBIFS error (pid 34456): could not find an empty LEB which sometimes happens after power cuts when we mount the file-system - UBIFS refuses it with the above error message which comes from the 'ubifs_rcvry_gc_commit()' function. I can reproduce this using the integck test with the UBIFS power cut emulation enabled. Analysis of the problem. Currently UBIFS replay seeks the journal heads to the last _replayed_ bud. But the buds are replayed out-of-order, so the replay basically seeks journal heads to the "random" bud belonging to this head, and not to the _last_ one. The result of this is that the GC head may be seeked to a full LEB with no free space, or very little free space. And 'ubifs_rcvry_gc_commit()' tries to find a fully or mostly dirty LEB to match the current GC head (because we need to garbage-collect that dirty LEB at one go, because we do not have @c->gc_lnum). So 'ubifs_find_dirty_leb()' fails and we fall back to finding an empty LEB and also fail. As a result - recovery fails and mounting fails. This patch teaches the replay to initialize the GC heads exactly to the latest buds, i.e. the buds which have the largest sequence number in corresponding log reference nodes. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Cc: stable@kernel.org
* UBIFS: do not free write-buffers when in R/O modeArtem Bityutskiy2011-05-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently UBIFS has a small optimization - it frees write-buffers when it is re-mounted from R/W mode to R/O mode. Of course, when it is mounted R/O, it does not allocate write-buffers as well. This optimization is nice but it leads to subtle problems and complications in recovery, which I can reproduce using the integck test. The symptoms are that after a power cut the file-system cannot be mounted if we first mount it R/O, and then re-mount R/W - 'ubifs_rcvry_gc_commit()' prints: UBIFS error (pid 34456): could not find an empty LEB Analysis of the problem. When mounting R/W, the reply process sets journal heads to buds [1], but when mounting R/O - it does not do this, because the write-buffers are not allocated. So 'ubifs_rcvry_gc_commit()' works completely differently for the same file-system but for the following 2 cases: 1. mounting R/W after a power cut and recover 2. mounting R/O after a power cut, re-mounting R/W and run deferred recovery In the former case, we have journal heads seeked to the a bud, in the latter case, they are non-seeked (wbuf->lnum == -1). So in the latter case we do not try to recover the GC LEB by garbage-collecting to the GC head, but we just try to find an empty LEB, and there may be no empty LEBs, so we just fail. On the other hand, in the former case (mount R/W), we are able to make a GC LEB (@c->gc_lnum) by garbage-collecting. Thus, let's remove this small nice optimization and always allocate write-buffers. This should not make too big difference - we have only 3 of them, each of max. write unit size, which is usually 2KiB. So this is about 6KiB of RAM for the typical case, and only when mounted R/O. [1]: Note, currently the replay process is setting (seeking) the journal heads to _some_ buds, not necessarily to the buds which had been the journal heads before the power cut happened. This will be fixed separately. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Cc: stable@kernel.org
* UBIFS: fix master node recoveryArtem Bityutskiy2011-04-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the following symptoms: 1. Unmount UBIFS cleanly. 2. Start mounting UBIFS R/W and have a power cut immediately 3. Start mounting UBIFS R/O, this succeeds 4. Try to re-mount UBIFS R/W - this fails immediately or later on, because UBIFS will write the master node to the flash area which has been written before. The analysis of the problem: 1. UBIFS is unmounted cleanly, both copies of the master node are clean. 2. UBIFS is being mounter R/W, starts changing master node copy 1, and a power cut happens. The copy N1 becomes corrupted. 3. UBIFS is being mounted R/O. It notices the copy N1 is corrupted and reads copy N2. Copy N2 is clean. 4. Because of R/O mode, UBIFS cannot recover copy 1. 5. The mount code (ubifs_mount()) sees that the master node is clean, so it decides that no recovery is needed. 6. We are re-mounting R/W. UBIFS believes no recovery is needed and starts updating the master node, but copy N1 is still corrupted and was not recovered! Fix this problem by marking the master node as dirty every time we recover it and we are in R/O mode. This forces further recovery and the UBIFS cleans-up the corruptions and recovers the copy N1 when re-mounting R/W later. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Cc: stable@kernel.org
* UBIFS: fix false assertion warning in case of I/O failuresArtem Bityutskiy2011-04-21
| | | | | | | | | | When UBIFS switches to R/O mode because it detects I/O failures, then when we unmount, we still may have allocated budget, and the assertions which verify that we have not budget will fire. But it is expected to have the budget in case of I/O failures, so the assertion warnings will be false. Suppress them for the I/O failure case. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* UBIFS: fix false space checking failureArtem Bityutskiy2011-04-20
| | | | | | | | | | | | | | | | | | This patch fixes UBIFS mount failure when the debugging support is enabled, we are recovering from a power cut, we were first mounter R/O and we are re-mounting R/W. In this case we should not assume that the amount of free space before we have re-mounted R/W and after are equivalent, because when we have mounted R/O the file-system is in a non-committed state so the amount of free space is slightly smaller, due to the fact that we cannot predict the amount of free space precisely before we commit. This patch fixes the issue by skipping the debugging check in case of recovery. This issue was reported by Caizhiyong <caizhiyong@huawei.com> here: http://thread.gmane.org/gmane.linux.drivers.mtd/34350/focus=34387 Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Reported-by: Caizhiyong <caizhiyong@huawei.com> Cc: stable@kernel.org [2.6.30+]
* UBIFS: fix compilation warnings when compiling with gcc 4.5Maksim Rayskiy2011-04-13
| | | | | | | | | | | | | | When compiling UBIFS with CONFIG_UBIFS_FS_DEBUG not set, gcc-4.5.2 generates a slew of "warning: statement with no effect" on references to non-void functions defined as 0. To avoid these warnings, replace #defines with dummy inline functions. Artem: massage the patch a bit, also remove the duplicate 'dbg_check_lprops()' prototype. Signed-off-by: Maksim Rayskiy <maksim.rayskiy@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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