12 Aug, 2010

1 commit


10 Aug, 2010

1 commit


04 Aug, 2010

1 commit


22 Apr, 2010

1 commit


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
     

28 Feb, 2010

3 commits

  • * _calc_stripe_info() changes to accommodate for grouping
    calculations. Returns additional information

    * old _prepare_pages() becomes _prepare_one_group()
    which stores pages belonging to one device group.

    * New _prepare_for_striping iterates on all groups calling
    _prepare_one_group().

    * Enable mounting of groups data_maps (group_width != 0)

    [QUESTION]
    what is faster A or B;
    A. x += stride;
    x = x % width + first_x;

    B x += stride
    if (x < last_x)
    x = first_x;

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     
  • We now support striping over mirror devices. Including variable sized
    stripe_unit.

    Some limits:
    * stripe_unit must be a multiple of PAGE_SIZE
    * stripe_unit * stripe_count is maximum upto 32-bit (4Gb)

    Tested RAID0 over mirrors, RAID0 only, mirrors only. All check.

    Design notes:
    * I'm not using a vectored raid-engine mechanism yet. Following the
    pnfs-objects-layout data-map structure, "Mirror" is just a private
    case of "group_width" == 1, and RAID0 is a private case of
    "Mirrors" == 1. The performance lose of the general case over the
    particular special case optimization is totally negligible, also
    considering the extra code size.

    * In general I added a prepare_stripes() stage that divides the
    to-be-io pages to the participating devices, the previous
    exofs_ios_write/read, now becomes _write/read_mirrors and a new
    write/read upper layer loops on all devices calling
    _write/read_mirrors. Effectively the prepare_stripes stage is the all
    secret.
    Also truncate need fixing to accommodate for striping.

    * In a RAID0 arrangement, in a regular usage scenario, if all inode
    layouts will start at the same device, the small files fill up the
    first device and the later devices stay empty, the farther the device
    the emptier it is.

    To fix that, each inode will start at a different stripe_unit,
    according to it's obj_id modulus number-of-stripe-units. And
    will then span all stripe-units in the same incrementing order
    wrapping back to the beginning of the device table. We call it
    a stripe-units moving window.

    Special consideration was taken to keep all devices in a mirror
    arrangement identical. So a broken osd-device could just be cloned
    from one of the mirrors and no FS scrubbing is needed. (We do that
    by rotating stripe-unit at a time and not a single device at a time.)

    TODO:
    We no longer verify object_length == inode->i_size in exofs_iget.
    (since i_size is stripped on multiple objects now).
    I should introduce a multiple-device attribute reading, and use
    it in exofs_iget.

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     
  • * Abstract away those members in exofs_sb_info that are related/needed
    by a layout into a new exofs_layout structure. Embed it in exofs_sb_info.

    * At exofs_io_state receive/keep a pointer to an exofs_layout. No need for
    an exofs_sb_info pointer, all we need is at exofs_layout.

    * Change any usage of above exofs_sb_info members to their new name.

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     

10 Dec, 2009

4 commits

  • This patch changes on-disk format, it is accompanied with a parallel
    patch to mkfs.exofs that enables multi-device capabilities.

    After this patch, old exofs will refuse to mount a new formatted FS and
    new exofs will refuse an old format. This is done by moving the magic
    field offset inside the FSCB. A new FSCB *version* field was added. In
    the future, exofs will refuse to mount unmatched FSCB version. To
    up-grade or down-grade an exofs one must use mkfs.exofs --upgrade option
    before mounting.

    Introduced, a new object that contains a *device-table*. This object
    contains the default *data-map* and a linear array of devices
    information, which identifies the devices used in the filesystem. This
    object is only written to offline by mkfs.exofs. This is why it is kept
    separate from the FSCB, since the later is written to while mounted.

    Same partition number, same object number is used on all devices only
    the device varies.

    * define the new format, then load the device table on mount time make
    sure every thing is supported.

    * Change I/O engine to now support Mirror IO, .i.e write same data
    to multiple devices, read from a random device to spread the
    read-load from multiple clients (TODO: stripe read)

    Implementation notes:
    A few points introduced in previous patch should be mentioned here:

    * Special care was made so absolutlly all operation that have any chance
    of failing are done before any osd-request is executed. This is to
    minimize the need for a data consistency recovery, to only real IO
    errors.

    * Each IO state has a kref. It starts at 1, any osd-request executed
    will increment the kref, finally when all are executed the first ref
    is dropped. At IO-done, each request completion decrements the kref,
    the last one to return executes the internal _last_io() routine.
    _last_io() will call the registered io_state_done. On sync mode a
    caller does not supply a done method, indicating a synchronous
    request, the caller is put to sleep and a special io_state_done is
    registered that will awaken the caller. Though also in sync mode all
    operations are executed in parallel.

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     
  • In anticipation for multi-device operations, we separate osd operations
    into an abstract I/O API. Currently only one device is used but later
    when adding more devices, we will drive all devices in parallel according
    to a "data_map" that describes how data is arranged on multiple devices.
    The file system level operates, like before, as if there is one object
    (inode-number) and an i_size. The io engine will split this to the same
    object-number but on multiple device.

    At first we introduce Mirror (raid 1) layout. But at the final outcome
    we intend to fully implement the pNFS-Objects data-map, including
    raid 0,4,5,6 over mirrored devices, over multiple device-groups. And
    more. See: http://tools.ietf.org/html/draft-ietf-nfsv4-pnfs-obj-12

    * Define an io_state based API for accessing osd storage devices
    in an abstract way.
    Usage:
    First a caller allocates an io state with:
    exofs_get_io_state(struct exofs_sb_info *sbi,
    struct exofs_io_state** ios);

    Then calles one of:
    exofs_sbi_create(struct exofs_io_state *ios);
    exofs_sbi_remove(struct exofs_io_state *ios);
    exofs_sbi_write(struct exofs_io_state *ios);
    exofs_sbi_read(struct exofs_io_state *ios);
    exofs_oi_truncate(struct exofs_i_info *oi, u64 new_len);

    And when done
    exofs_put_io_state(struct exofs_io_state *ios);

    * Convert all source files to use this new API
    * Convert from bio_alloc to bio_kmalloc
    * In io engine we make use of the now fixed osd_req_decode_sense

    There are no functional changes or on disk additions after this patch.

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     
  • Even though exofs has a 4k block size, statfs blocks
    is in sectors (512 bytes).

    Also if target returns 0 for capacity then make it
    ULLONG_MAX. df does not like zero-size filesystems

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     
  • It is important to print in the logs when a filesystem was
    mounted and eventually unmounted.

    Print the osd-device's osd_name and pid the FS was
    mounted/unmounted on.

    TODO: How to also print the namespace path the filesystem was
    mounted on?

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     

24 Sep, 2009

1 commit

  • the two places inside exofs that where taking the BKL were:
    exofs_put_super() - .put_super
    and
    exofs_sync_fs() - which is .sync_fs and is also called from
    .write_super.

    Now exofs_sync_fs() is protected from itself by also taking
    the sb_lock.

    exofs_put_super() directly calls exofs_sync_fs() so there is no
    danger between these two either.

    In anyway there is absolutely nothing dangerous been done
    inside exofs_sync_fs().

    Unless there is some subtle race with the actual lifetime of
    the super_block in regard to .put_super and some other parts
    of the VFS. Which is highly unlikely.

    Signed-off-by: Boaz Harrosh
    Signed-off-by: Al Viro

    Boaz Harrosh
     

13 Jul, 2009

1 commit

  • * Remove smp_lock.h from files which don't need it (including some headers!)
    * Add smp_lock.h to files which do need it
    * Make smp_lock.h include conditional in hardirq.h
    It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

    This will make hardirq.h inclusion cheaper for every PREEMPT=n config
    (which includes allmodconfig/allyesconfig, BTW)

    Signed-off-by: Alexey Dobriyan
    Signed-off-by: Linus Torvalds

    Alexey Dobriyan
     

21 Jun, 2009

2 commits

  • The use of file_fsync() in exofs_file_sync() is not necessary since it
    does some extra stuff not used by exofs. Open code just the parts that
    are currently needed.

    TODO: Farther optimization can be done to sync the sb only on inode
    update of new files, Usually the sb update is not needed in exofs.

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     
  • Boaz,
    Congrats on getting all the OSD stuff into 2.6.30!
    I just pulled the git, and saw that the IBM copyrights are still there.
    Please remove them from all files:
    * Copyright (C) 2005, 2006
    * International Business Machines

    IBM has revoked all rights on the code - they gave it to me.

    Thanks!
    Avishay

    Signed-off-by: Avishay Traeger
    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     

12 Jun, 2009

4 commits

  • Add a ->sync_fs method for data integrity syncs, and reimplement
    ->write_super ontop of it.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Al Viro

    Christoph Hellwig
     
  • Push down lock_super into ->write_super instances and remove it from the
    caller.

    Following filesystem don't need ->s_lock in ->write_super and are skipped:

    * bfs, nilfs2 - no other uses of s_lock and have internal locks in
    ->write_super
    * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock
    * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in
    ->write_super
    * xfs - no other uses of s_lock and uses internal lock (buffer lock on
    superblock buffer) to serialize ->write_super. Also xfs_fs_write_super
    is superflous and will go away in the next merge window

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Al Viro

    Christoph Hellwig
     
  • Move BKL into ->put_super from the only caller. A couple of
    filesystems had trivial enough ->put_super (only kfree and NULLing of
    s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
    hugetlbfs, omfs, qnx4, shmem, all others got the full treatment. Most
    of them probably don't need it, but I'd rather sort that out individually.
    Preferably after all the other BKL pushdowns in that area.

    [AV: original used to move lock_super() down as well; these changes are
    removed since we don't do lock_super() at all in generic_shutdown_super()
    now]
    [AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Al Viro

    Christoph Hellwig
     
  • We just did a full fs writeout using sync_filesystem before, and if
    that's not enough for the filesystem it can perform it's own writeout
    in ->put_super, which many filesystems already do.

    Move a call to foofs_write_super into every foofs_put_super for now to
    guarantee identical behaviour until it's cleaned up by the individual
    filesystem maintainers.

    Exceptions:

    - affs already has identical copy & pasted code at the beginning of
    affs_put_super so no need to do it twice.
    - xfs does the right thing without it and I have changes pending for
    the xfs tree touching this are so I don't really need conflicts
    here..

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Al Viro

    Christoph Hellwig
     

01 Apr, 2009

2 commits

  • implement export_operations and set in superblock.
    It is now posible to export exofs via nfs

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh
     
  • This patch ties all operation vectors into a file system superblock
    and registers the exofs file_system_type at module's load time.

    * The file system control block (AKA on-disk superblock) resides in
    an object with a special ID (defined in common.h).
    Information included in the file system control block is used to
    fill the in-memory superblock structure at mount time. This object
    is created before the file system is used by mkexofs.c It contains
    information such as:
    - The file system's magic number
    - The next inode number to be allocated

    Signed-off-by: Boaz Harrosh

    Boaz Harrosh