04 Jul, 2011

4 commits

  • We have too many different debugging checks - lessen the amount by merging all
    index-related checks into one. At the same time, move the "force in-the-gap"
    test to the "index checks" class, because it is too heavy for the "general"
    class.

    This patch merges TNC, Old index, and Index size check and calles this just
    "index checks".

    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     
  • This patch introduces helper functions for all debugging checks, so instead of
    doing

    if (!(ubifs_chk_flags & UBIFS_CHK_GEN))

    we now do

    if (!dbg_is_chk_gen(c))

    This is a preparation to further changes where the flags will go away, and
    we'll need to only change the helper functions, but the code which utilizes
    them won't be touched.

    At the same time this patch removes 'dbg_force_in_the_gaps()',
    'dbg_force_in_the_gaps_enabled()', and dbg_failure_mode helpers for
    consistency.

    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     
  • We have 3 znode flags: cow, obsolete, dirty. For the last flag we have a
    'ubifs_zn_dirty()' helper function, but for the other 2 flags we use
    'test_bit()' directly.

    This patch makes the situation more consistent and introduces helpers for the
    other 2 flags: 'ubifs_zn_cow()' and 'ubifs_zn_obsolete()'.

    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     
  • If commit failed and it is in broken state, UBIFS switches to R/O mode. Most
    operations return -EROFS in this case, except of commit which returns -EINVAL.
    Make it return -EROFS too for consistency. This is also important for our power
    cut emulation testing.

    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     

14 May, 2011

1 commit

  • 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
     

05 Apr, 2011

1 commit

  • This fix makes the 'dbg_check_old_index()' function return
    immediately if debugging is disabled, instead of executing
    incorrect 'goto out' which causes UBIFS to:

    1. Allocate memory
    2. Read the flash

    On every commit. OK, we do not commit that often, but it is
    still silly to do unneeded I/O anyway.

    Credits to coverity for spotting this silly issue.

    Signed-off-by: Artem Bityutskiy
    Cc: stable@kernel.org

    Artem Bityutskiy
     

25 Jan, 2011

1 commit

  • This patch fixes suboptimal UBIFS 'sync_fs()' implementation which causes
    flash I/O even if the file-system is synchronized. E.g., a 'printk()'
    in the MTD erasure function (e.g., 'nand_erase_nand()') can show that
    for every 'sync' shell command UBIFS erases at least one eraseblock.

    So '$ while true; do sync; done' will cause huge amount of flash I/O.

    The reason for this is that UBIFS commits in 'sync_fs()', and starts the
    commit even if there is nothing to commit, e.g., it anyway changes the
    log. This patch adds a check in the 'do_commit()' UBIFS functions which
    prevents the commit if there is nothing to commit.

    Reported-by: Hans J. Koch
    Tested-by: John Ogness
    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     

20 Sep, 2010

1 commit

  • Commit 2fde99cb55fb9d9b88180512a5e8a5d939d27fec "UBIFS: mark VFS SB RO too"
    introduced regression. This commit made UBIFS set the 'MS_RDONLY' flag in the
    VFS superblock when it switches to R/O mode due to an error. This was done
    to make VFS show the R/O UBIFS flag in /proc/mounts.

    However, several places in UBIFS relied on the 'MS_RDONLY' flag and assume this
    flag can only change when we re-mount. For example, 'ubifs_put_super()'.

    This patch introduces new UBIFS flag - 'c->ro_mount' which changes only when
    we re-mount, and preserves the way UBIFS was originally mounted (R/W or R/O).
    This allows us to de-initialize UBIFS cleanly in 'ubifs_put_super()'.

    This patch also changes all 'ubifs_assert(!c->ro_media)' assertions to
    'ubifs_assert(!c->ro_media && !c->ro_mount)', because we never should write
    anything if the FS was mounter R/O.

    All the places where we test for 'MS_RDONLY' flag in the VFS SB were changed
    and now we test the 'c->ro_mount' flag instead, because it preserves the
    original UBIFS mount type, unlike the 'MS_RDONLY' flag.

    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     

17 Sep, 2010

1 commit

  • The R/O state may have various reasons:

    1. The UBI volume is R/O
    2. The FS is mounted R/O
    3. The FS switched to R/O mode because of an error

    However, in UBIFS we have only one variable which represents cases
    1 and 3 - 'c->ro_media'. Indeed, we set this to 1 if we switch to
    R/O mode due to an error, and then we test it in many places to
    make sure that we stop writing as soon as the error happens.

    But this is very unclean. One consequence of this, for example, is
    that in 'ubifs_remount_fs()' we use 'c->ro_media' to check whether
    we are in R/O mode because on an error, and we print a message
    in this case. However, if we are in R/O mode because the media
    is R/O, our message is bogus.

    This patch introduces new flag - 'c->ro_error' which is set when
    we switch to R/O mode because of an error. It also changes all
    "if (c->ro_media)" checks to "if (c->ro_error)" checks, because
    this is what the checks actually mean. We do not need to check
    for 'c->ro_media' because if the UBI volume is in R/O mode, we
    do not allow R/W mounting, and now writes can happen. This is
    guaranteed by VFS. But it is good to double-check this, so this
    patch also adds many "ubifs_assert(!c->ro_media)" checks.

    In the 'ubifs_remount_fs()' function this patch makes a bit more
    changes - it fixes the error messages as well.

    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     

30 Mar, 2010

1 commit

  • …it 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>

    Tejun Heo
     

24 Jul, 2009

1 commit


03 Dec, 2008

1 commit


06 Nov, 2008

1 commit

  • Remove the "UBIFS background thread ubifs_bgd0_0 started" message.
    We kill the background thread when we switch to R/O mode, and
    start it again whan we switch to R/W mode. OLPC is doing this
    many times during boot, and we see this message many times as
    well, which is irritating. So just kill the message.

    Signed-off-by: Artem Bityutskiy

    Artem Bityutskiy
     

13 Aug, 2008

1 commit


15 Jul, 2008

1 commit