04 Jan, 2012

4 commits


28 May, 2011

2 commits

  • ncpfs does not handle references to unlinked directories (or so it would
    seem given the ncp_rmdir check). Since it is also possible to rename over
    an empty directory, perform the same check here.

    CC: Petr Vandrovec
    CC: linux-kernel@vger.kernel.org
    Signed-off-by: Sage Weil
    Signed-off-by: Al Viro

    Sage Weil
     
  • ncpfs returns EBUSY if there are any references to the directory. The
    dentry_unhash call only unhashes the dentry if there are no references.

    CC: Petr Vandrovec
    CC: linux-kernel@vger.kernel.org
    Signed-off-by: Sage Weil
    Signed-off-by: Al Viro

    Sage Weil
     

26 May, 2011

2 commits


13 Jan, 2011

2 commits


07 Jan, 2011

9 commits

  • Require filesystems be aware of .d_revalidate being called in rcu-walk
    mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
    -ECHILD from all implementations.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • 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
     
  • dget_locked was a shortcut to avoid the lazy lru manipulation when we already
    held dcache_lock (lru manipulation was relatively cheap at that point).
    However, how that the lru lock is an innermost one, we never hold it at any
    caller, so the lock cost can now be avoided. We already have well working lazy
    dcache LRU, so it should be fine to defer LRU manipulations to scan time.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • dcache_lock no longer protects anything. remove it.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
    using dcache_lock for these anyway (eg. using i_mutex).

    Note: if we change the locking rule in future so that ->d_child protection is
    provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
    But it would be an exception to an otherwise regular locking scheme, so we'd
    have to see some good results. Probably not worthwhile.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • Change d_hash so it may be called from lock-free RCU lookups. See similar
    patch for d_compare for details.

    For in-tree filesystems, this is just a mechanical change.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • Change d_compare so it may be called from lock-free RCU lookups. This
    does put significant restrictions on what may be done from the callback,
    however there don't seem to have been any problems with in-tree fses.
    If some strange use case pops up that _really_ cannot cope with the
    rcu-walk rules, we can just add new rcu-unaware callbacks, which would
    cause name lookup to drop out of rcu-walk mode.

    For in-tree filesystems, this is just a mechanical change.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • smpfs and ncpfs want to update a live dentry name in-place. Rather than
    have them open code the locking, provide a documented dcache API.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • Change d_delete from a dentry deletion notification to a dentry caching
    advise, more like ->drop_inode. Require it to be constant and idempotent,
    and not take d_lock. This is how all existing filesystems use the callback
    anyway.

    This makes fine grained dentry locking of dput and dentry lru scanning
    much simpler.

    Signed-off-by: Nick Piggin

    Nick Piggin
     

18 Nov, 2010

1 commit


05 Oct, 2010

1 commit

  • Dozen of changes in ncpfs to provide some locking other than BKL.

    In readdir cache unlock and mark complete first page as last operation,
    so it can be used for synchronization, as code intended.

    When updating dentry name on case insensitive filesystems do at least
    some basic locking...

    Hold i_mutex when updating inode fields.

    Push some ncp_conn_is_valid down to ncp_request. Connection can become
    invalid at any moment, and fewer error code paths to test the better.

    Use i_size_{read,write} to modify file size.

    Set inode's backing_dev_info as ncpfs has its own special bdi.

    In ioctl unbreak ioctls invoked on filesystem mounted 'ro' - tests are
    for inode writeable or owner match, but were turned to filesystem
    writeable and inode writeable or owner match. Also collect all permission
    checks in single place.

    Add some locking, and remove comments saying that it would be cool to
    add some locks to the code.

    Constify some pointers.

    Signed-off-by: Petr Vandrovec
    Signed-off-by: Arnd Bergmann

    Petr Vandrovec
     

28 May, 2010

1 commit

  • 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
     

17 May, 2010

1 commit

  • Convert ncp_ioctl to an unlocked_ioctl and push down the bkl into it.

    Signed-off-by: John Kacur
    Cc: Arnd Bergmann
    Cc: Thomas Gleixner
    Cc: Ingo Molnar
    Cc: Petr Vandrovec
    Signed-off-by: Frederic Weisbecker

    John Kacur
     

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
     

23 Sep, 2009

1 commit

  • This function uses signed integers for the unix_date and local variables -
    if a negative number is supplied and the leap-year condition is not met,
    month will be 0, leading to a later read of day_n[-1]

    Signed-off-by: Roel Kluin
    Cc: Petr Vandrovec
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Roel Kluin
     

28 Mar, 2009

1 commit


27 Jul, 2008

1 commit


13 Feb, 2007

1 commit

  • Many struct inode_operations in the kernel can be "const". Marking them const
    moves these to the .rodata section, which avoids false sharing with potential
    dirty data. In addition it'll catch accidental writes at compile time to
    these shared resources.

    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

09 Dec, 2006

1 commit


01 Oct, 2006

1 commit

  • The ncp specific compat ioctls are clearly local to one file system, so the
    code can better live there.

    This version of the patch moves everything into the generic ioctl handler
    and uses it for both 32 and 64 bit calls.

    Signed-off-by: Arnd Bergmann
    Signed-off-by: Petr Vandrovec
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Petr Vandrovec
     

01 Jul, 2006

1 commit


29 Mar, 2006

1 commit

  • This is a conversion to make the various file_operations structs in fs/
    const. Basically a regexp job, with a few manual fixups

    The goal is both to increase correctness (harder to accidentally write to
    shared datastructures) and reducing the false sharing of cachelines with
    things that get dirty in .data (while .rodata is nicely read only and thus
    cache clean)

    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

09 Jan, 2006

1 commit

  • Some long time ago, dentry struct was carefully tuned so that on 32 bits
    UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
    of memory cache lines.

    Then RCU was added and dentry struct enlarged by two pointers, with nice
    results for SMP, but not so good on UP, because breaking the above tuning
    (128 + 8 = 136 bytes)

    This patch reverts this unwanted side effect, by using an union (d_u),
    where d_rcu and d_child are placed so that these two fields can share their
    memory needs.

    At the time d_free() is called (and d_rcu is really used), d_child is known
    to be empty and not touched by the dentry freeing.

    Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
    the previous content of d_child is not needed if said dentry was unhashed
    but still accessed by a CPU because of RCU constraints)

    As dentry cache easily contains millions of entries, a size reduction is
    worth the extra complexity of the ugly C union.

    Signed-off-by: Eric Dumazet
    Cc: Dipankar Sarma
    Cc: Maneesh Soni
    Cc: Miklos Szeredi
    Cc: "Paul E. McKenney"
    Cc: Ian Kent
    Cc: Paul Jackson
    Cc: Al Viro
    Cc: Christoph Hellwig
    Cc: Trond Myklebust
    Cc: Neil Brown
    Cc: James Morris
    Cc: Stephen Smalley
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Eric Dumazet
     

26 Jun, 2005

1 commit


17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds