13 Jan, 2011

1 commit


07 Jan, 2011

2 commits

  • Reduce some branches and memory accesses in dcache lookup by adding dentry
    flags to indicate common d_ops are set, rather than having to check them.
    This saves a pointer memory access (dentry->d_op) in common path lookup
    situations, and saves another pointer load and branch in cases where we
    have d_op but not the particular operation.

    Patched with:

    git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • RCU free the struct inode. This will allow:

    - Subsequent store-free path walking patch. The inode must be consulted for
    permissions when walking, so an RCU inode reference is a must.
    - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
    to take i_lock no longer need to take sb_inode_list_lock to walk the list in
    the first place. This will simplify and optimize locking.
    - Could remove some nested trylock loops in dcache code
    - Could potentially simplify things a bit in VM land. Do not need to take the
    page lock to follow page->mapping.

    The downsides of this is the performance cost of using RCU. In a simple
    creat/unlink microbenchmark, performance drops by about 10% due to inability to
    reuse cache-hot slab objects. As iterations increase and RCU freeing starts
    kicking over, this increases to about 20%.

    In cases where inode lifetimes are longer (ie. many inodes may be allocated
    during the average life span of a single inode), a lot of this cache reuse is
    not applicable, so the regression caused by this patch is smaller.

    The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
    however this adds some complexity to list walking and store-free path walking,
    so I prefer to implement this at a later date, if it is shown to be a win in
    real situations. I haven't found a regression in any non-micro benchmark so I
    doubt it will be a problem.

    Signed-off-by: Nick Piggin

    Nick Piggin
     

29 Oct, 2010

1 commit


26 Oct, 2010

1 commit


10 Sep, 2010

1 commit

  • Commit 9eed1fb721c ("minix: replace inode uid,gid,mode init with helper")
    broke directory creation on minix filesystems.

    Fix it by passing the needed mode flag to inode init helper.

    Signed-off-by: Jorge Boncompte [DTI2]
    Cc: Dmitry Monakhov
    Cc: Al Viro
    Cc: [2.6.35.x]
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jorge Boncompte [DTI2]
     

10 Aug, 2010

6 commits

  • We need to wait for completion of possible writeback in progress
    before we clear on-disk inode during deletion.

    Signed-off-by: Al Viro

    Al Viro
     
  • Replace inode_setattr with opencoded variants of it in all callers. This
    moves the remaining call to vmtruncate into the filesystem methods where it
    can be replaced with the proper truncate sequence.

    In a few cases it was obvious that we would never end up calling vmtruncate
    so it was left out in the opencoded variant:

    spufs: explicitly checks for ATTR_SIZE earlier
    btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
    ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above

    In addition to that ncpfs called inode_setattr with handcrafted iattrs,
    which allowed to trim down the opencoded variant.

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

    Christoph Hellwig
     
  • For the new truncate sequence every filesystem that wants to truncate on-disk
    state needs a seattr method. Convert the remaining filesystems that implement
    the truncate inode operation to have its own setattr method.

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

    Christoph Hellwig
     
  • Move the call to vmtruncate to get rid of accessive blocks to the callers
    in preparation of the new truncate sequence and rename the non-truncating
    version to block_write_begin.

    While we're at it also remove several unused arguments to block_write_begin.

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

    Christoph Hellwig
     
  • Split up the block_write_begin implementation - __block_write_begin is a new
    trivial wrapper for block_prepare_write that always takes an already
    allocated page and can be either called from block_write_begin or filesystem
    code that already has a page allocated. Remove the handling of already
    allocated pages from block_write_begin after switching all callers that
    do it to __block_write_begin.

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

    Christoph Hellwig
     
  • For filesystem that implement directories in pagecache we call
    block_write_begin with an already allocated page for this code, while the
    normal regular file write path uses the default block_write_begin behaviour.

    Get rid of the __foofs_write_begin helper and opencode the normal write_begin
    call in foofs_write_begin, while adding a new foofs_prepare_chunk helper for
    the directory code. The added benefit is that foofs_prepare_chunk has
    a much saner calling convention.

    Note that the interruptible flag passed into block_write_begin is always
    ignored if we already pass in a page (see next patch for details), and
    we never were doing truncations of exessive blocks for this case either so we
    can switch directly to block_write_begin_newtrunc.

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

    Christoph Hellwig
     

05 Jun, 2010

1 commit


28 May, 2010

3 commits

  • gets minix get_dir_page() in sync with its analogs; back in 2007
    Nick has switched read_cache_page() and friends to sync behaviour
    (i.e. they wait for the page to get unlocked, check if it's uptodate
    and if it isn't return ERR_PTR(-EIO) instead) and removed the
    duplicate logics from the callers. In case of fs/minix/dir.c he'd
    removed only half of that...

    Signed-off-by: Al Viro

    Al Viro
     
  • The MINIX filesystem driver used a constant number of indirect block
    pointers in an indirect block. This worked only for filesystems with 1kb
    block, while the MINIX default block size is now 4kb. As a consequence,
    large files were read incorrectly on such filesystems and writing a
    large file would cause the filesystem to become corrupted. This patch
    computes the number of indirect block pointers based on the block size,
    making the driver work for each block size.

    I would like to thank Feiran Zheng ('Fam') for pointing out the cause
    of the corruption.

    Signed-off-by: Erik van der Kouwe
    Signed-off-by: Al Viro

    Erik van der Kouwe
     
  • We don't name our generic fsync implementations very well currently.
    The no-op implementation for in-memory filesystems currently is called
    simple_sync_file which doesn't make too much sense to start with,
    the the generic one for simple filesystems is called simple_fsync
    which can lead to some confusion.

    This patch renames the generic file fsync method to generic_file_fsync
    to match the other generic_file_* routines it is supposed to be used
    with, and the no-op implementation to noop_fsync to make it obvious
    what to expect. In addition add some documentation for both methods.

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

    Christoph Hellwig
     

22 May, 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
     

06 Mar, 2010

1 commit

  • This gives the filesystem more information about the writeback that
    is happening. Trond requested this for the NFS unstable write handling,
    and other filesystems might benefit from this too by beeing able to
    distinguish between the different callers in more detail.

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

    Christoph Hellwig
     

23 Sep, 2009

1 commit

  • There are a few places in the Minix FS code where the "inode" field of a
    minix_dir_entry is used without checking first to see if the dirent is
    really a minix3_dir_entry. The inode number in a V1/V2 dirent is 16 bits,
    whereas that in a V3 dirent is 32 bits.

    Accessing it as a 16 bit field when it really should be accessed as a 32
    bit field probably kinda sorta works on a little-endian machine, but leads
    to some rather odd behaviour on big-endian machines.

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Doug Graham
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Doug Graham
     

23 Jun, 2009

1 commit

  • I happened to find that fs/minix/minix.h doesn't guard double include.

    Yes, I know this never cause something destructive because this is
    self-evidence that no source file includes minix.h twice, but I think
    fixing this is better than disregarding it.

    Signed-off-by: Hitoshi Mitake
    Signed-off-by: Linus Torvalds

    Hitoshi Mitake
     

17 Jun, 2009

1 commit


12 Jun, 2009

2 commits

  • * get minix_write_inode() to honour the second argument
    * now we can use simple_fsync() for minixfs

    Signed-off-by: Al Viro

    Al Viro
     
  • 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
     

03 Apr, 2009

1 commit


23 Mar, 2009

1 commit


22 Jan, 2009

1 commit


07 Jan, 2009

1 commit


14 Nov, 2008

1 commit

  • Wrap access to task credentials so that they can be separated more easily from
    the task_struct during the introduction of COW creds.

    Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

    Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
    sense to use RCU directly rather than a convenient wrapper; these will be
    addressed by later patches.

    Signed-off-by: David Howells
    Reviewed-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David Howells
     

27 Jul, 2008

1 commit

  • Kmem cache passed to constructor is only needed for constructors that are
    themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
    passed kmem cache in non-trivial way, so pass only pointer to object.

    Non-trivial places are:
    arch/powerpc/mm/init_64.c
    arch/powerpc/mm/hugetlbpage.c

    This is flag day, yes.

    Signed-off-by: Alexey Dobriyan
    Acked-by: Pekka Enberg
    Acked-by: Christoph Lameter
    Cc: Jon Tollefson
    Cc: Nick Piggin
    Cc: Matt Mackall
    [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
    [akpm@linux-foundation.org: fix mm/slab.c]
    [akpm@linux-foundation.org: fix ubifs]
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexey Dobriyan
     

26 Jul, 2008

1 commit


08 Feb, 2008

1 commit

  • Stop the MINIX filesystem from using iget() and read_inode(). Replace
    minix_read_inode() with minix_iget(), and call that instead of iget().
    minix_iget() then uses iget_locked() directly and returns a proper error code
    instead of an inode in the event of an error.

    minix_fill_super() returns any error incurred when getting the root inode
    instead of EINVAL.

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: David Howells
    Acked-by: Christoph Hellwig
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Howells
     

17 Oct, 2007

4 commits

  • This attempts to address CVE-2006-6058
    http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-6058

    first reported at http://projects.info-pull.com/mokb/MOKB-17-11-2006.html

    Essentially a corrupted minix dir inode reporting a very large
    i_size will loop for a very long time in minix_readdir, minix_find_entry,
    etc, because on EIO they just move on to try the next page. This is
    under the BKL, printk-storming as well. This can lock up the machine
    for a very long time. Simply ratelimiting the printks gets things back
    under control. Make the message a bit more informative while we're here.

    Signed-off-by: Eric Sandeen
    Cc: Bodo Eggert
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Eric Sandeen
     
  • Signed-off-by: Philippe De Muyter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Philippe De Muyter
     
  • Slab constructors currently have a flags parameter that is never used. And
    the order of the arguments is opposite to other slab functions. The object
    pointer is placed before the kmem_cache pointer.

    Convert

    ctor(void *object, struct kmem_cache *s, unsigned long flags)

    to

    ctor(struct kmem_cache *s, void *object)

    throughout the kernel

    [akpm@linux-foundation.org: coupla fixes]
    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • Signed-off-by: Nick Piggin
    Cc: Andries Brouwer
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     

20 Jul, 2007

1 commit

  • Slab destructors were no longer supported after Christoph's
    c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been
    BUGs for both slab and slub, and slob never supported them
    either.

    This rips out support for the dtor pointer from kmem_cache_create()
    completely and fixes up every single callsite in the kernel (there were
    about 224, not including the slab allocator definitions themselves,
    or the documentation references).

    Signed-off-by: Paul Mundt

    Paul Mundt
     

10 Jul, 2007

1 commit


22 May, 2007

1 commit

  • First thing mm.h does is including sched.h solely for can_do_mlock() inline
    function which has "current" dereference inside. By dealing with can_do_mlock()
    mm.h can be detached from sched.h which is good. See below, why.

    This patch
    a) removes unconditional inclusion of sched.h from mm.h
    b) makes can_do_mlock() normal function in mm/mlock.c
    c) exports can_do_mlock() to not break compilation
    d) adds sched.h inclusions back to files that were getting it indirectly.
    e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
    getting them indirectly

    Net result is:
    a) mm.h users would get less code to open, read, preprocess, parse, ... if
    they don't need sched.h
    b) sched.h stops being dependency for significant number of files:
    on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
    after patch it's only 3744 (-8.3%).

    Cross-compile tested on

    all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
    alpha alpha-up
    arm
    i386 i386-up i386-defconfig i386-allnoconfig
    ia64 ia64-up
    m68k
    mips
    parisc parisc-up
    powerpc powerpc-up
    s390 s390-up
    sparc sparc-up
    sparc64 sparc64-up
    um-x86_64
    x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

    as well as my two usual configs.

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

    Alexey Dobriyan
     

17 May, 2007

1 commit

  • SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.

    Signed-off-by: Christoph Lameter
    Cc: David Howells
    Cc: Jens Axboe
    Cc: Steven French
    Cc: Michael Halcrow
    Cc: OGAWA Hirofumi
    Cc: Miklos Szeredi
    Cc: Steven Whitehouse
    Cc: Roman Zippel
    Cc: David Woodhouse
    Cc: Dave Kleikamp
    Cc: Trond Myklebust
    Cc: "J. Bruce Fields"
    Cc: Anton Altaparmakov
    Cc: Mark Fasheh
    Cc: Paul Mackerras
    Cc: Christoph Hellwig
    Cc: Jan Kara
    Cc: David Chinner
    Cc: "David S. Miller"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter