10 Mar, 2011

1 commit

  • Code has been converted over to the new explicit on-stack plugging,
    and delay users have been converted to use the new API for that.
    So lets kill off the old plugging along with aops->sync_page().

    Signed-off-by: Jens Axboe

    Jens Axboe
     

07 Jan, 2011

1 commit

  • 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


22 Oct, 2010

1 commit

  • All uses of the BKL in qnx4 were the result of a pushdown into
    code that doesn't really need it. As Christoph points out, this
    is a read-only file system, which eliminates most of the races in
    readdir/lookup.

    Signed-off-by: Arnd Bergmann
    Acked-by: Anders Larsen
    Cc: Christoph Hellwig

    Arnd Bergmann
     

05 Oct, 2010

1 commit

  • This patch is a preparation necessary to remove the BKL from do_new_mount().
    It explicitly adds calls to lock_kernel()/unlock_kernel() around
    get_sb/fill_super operations for filesystems that still uses the BKL.

    I've read through all the code formerly covered by the BKL inside
    do_kern_mount() and have satisfied myself that it doesn't need the BKL
    any more.

    do_kern_mount() is already called without the BKL when mounting the rootfs
    and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
    from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
    through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
    afs_mntpt_follow_link(). Both later functions are actually the filesystems
    follow_link inode operation. vfs_kern_mount() is calling the specified
    get_sb function and lets the filesystem do its job by calling the given
    fill_super function.

    Therefore I think it is safe to push down the BKL from the VFS to the
    low-level filesystems get_sb/fill_super operation.

    [arnd: do not add the BKL to those file systems that already
    don't use it elsewhere]

    Signed-off-by: Jan Blunck
    Signed-off-by: Arnd Bergmann
    Cc: Matthew Wilcox
    Cc: Christoph Hellwig

    Jan Blunck
     

10 Aug, 2010

1 commit


28 May, 2010

2 commits

  • 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
     
  • Do not use the fallback default_llseek() if the readdir operation of the
    filesystem still uses the big kernel lock.

    Since llseek() modifies
    file->f_pos of the directory directly it may need locking to not confuse
    readdir which usually uses file->f_pos directly as well

    Since the special characteristics of the BKL (unlocked on schedule) are
    not necessary in this case, the inode mutex can be used for locking as
    provided by generic_file_llseek(). This is only possible since all
    filesystems, except reiserfs, either use a directory as a flat file or
    with disk address offsets. Reiserfs on the other hand uses a 32bit hash
    off the filename as the offset so generic_file_llseek() can get used as
    well since the hash is always smaller than sb->s_maxbytes (= (512 << 32) -
    blocksize).

    Signed-off-by: Jan Blunck
    Acked-by: Jan Kara
    Acked-by: Anders Larsen
    Cc: Frederic Weisbecker
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    jan Blunck
     

04 Feb, 2010

1 commit

  • As an identical match is wanted in this case, strcmp can be used instead.

    The semantic match that lead to detecting this problem is as follows:
    (http://coccinelle.lip6.fr/)

    //
    @@
    expression foo;
    constant char *abc;
    @@

    *strncmp(foo, abc, sizeof(abc))
    //

    Signed-off-by: Julia Lawall
    Signed-off-by: Anders Larsen
    Signed-off-by: Jiri Kosina

    Julia Lawall
     

16 Dec, 2009

2 commits

  • Use hweight8 instead of counting for each bit

    Signed-off-by: Akinobu Mita
    Acked-by: Anders Larsen
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • commit 945ffe54bbd56ceed62de3b908800fd7c6ffb284 ("qnx4: remove write support") removed the (defunct)
    write support but missed a chunk of related, dead code.

    Signed-off-by: Anders Larsen
    Cc: Jiri Kosina
    Acked-by: Christoph Hellwig
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Anders Larsen
     

09 Nov, 2009

1 commit


23 Sep, 2009

1 commit

  • qnx4 wrte support has never been fully implement, is broken since the dawn
    of time and hasn't been actively developed since before git history
    started.

    Instead of letting it further bitrot and complicate API transition (like
    the new truncate code) remove it.

    Signed-off-by: Christoph Hellwig
    Cc: Anders Larsen
    Cc: Nick Piggin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Hellwig
     

12 Jun, 2009

3 commits

  • fs-internal parts of qnx4_fs.h taken to fs/qnx4/qnx4.h, includes adjusted,
    qnx4_fs.h doesn't need unifdef anymore.

    Signed-off-by: Al Viro

    Al Viro
     
  • * have directory operations use mark_buffer_dirty_inode(),
    so that sync_mapping_buffers() would get those.
    * make qnx4_write_inode() honour its last argument.
    * get rid of insane copies of very ancient "walk the indirect blocks"
    in qnx4/fsync - they never matched the actual fs layout and, fortunately,
    never'd been called. Again, all this junk is not needed; ->fsync()
    should just do sync_mapping_buffers + sync_inode (and if we implement
    block allocation for qnx4, we'll need to use mark_buffer_dirty_inode()
    for extent blocks)

    Signed-off-by: Al Viro

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

    Christoph Hellwig
     

03 Apr, 2009

1 commit


22 Jan, 2009

1 commit


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
     

08 Feb, 2008

1 commit

  • Stop the QNX4 filesystem from using iget() and read_inode(). Replace
    qnx4_read_inode() with qnx4_iget(), and call that instead of iget().
    qnx4_iget() then uses iget_locked() directly and returns a proper error code
    instead of an inode in the event of an error.

    qnx4_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
    Cc: Anders Larsen
    Acked-by: Christoph Hellwig
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Howells
     

17 Oct, 2007

2 commits

  • 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
    Acked-by: Anders Larsen
    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