03 Mar, 2011

1 commit


13 Jan, 2011

1 commit


07 Jan, 2011

5 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
     
  • 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
     
  • 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
     

29 Oct, 2010

1 commit


26 Oct, 2010

2 commits


23 Oct, 2010

1 commit

  • * 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: (30 commits)
    BKL: remove BKL from freevxfs
    BKL: remove BKL from qnx4
    autofs4: Only declare function when CONFIG_COMPAT is defined
    autofs: Only declare function when CONFIG_COMPAT is defined
    ncpfs: Lock socket in ncpfs while setting its callbacks
    fs/locks.c: prepare for BKL removal
    BKL: Remove BKL from ncpfs
    BKL: Remove BKL from OCFS2
    BKL: Remove BKL from squashfs
    BKL: Remove BKL from jffs2
    BKL: Remove BKL from ecryptfs
    BKL: Remove BKL from afs
    BKL: Remove BKL from USB gadgetfs
    BKL: Remove BKL from autofs4
    BKL: Remove BKL from isofs
    BKL: Remove BKL from fat
    BKL: Remove BKL from ext2 filesystem
    BKL: Remove BKL from do_new_mount()
    BKL: Remove BKL from cgroup
    BKL: Remove BKL from NTFS
    ...

    Linus Torvalds
     

12 Oct, 2010

1 commit


05 Oct, 2010

2 commits

  • The BKL is only used in put_super and fill_super that are both protected by
    the superblocks s_umount rw_semaphore. Therefore it is safe to remove the
    BKL entirely.

    Signed-off-by: Jan Blunck
    Signed-off-by: Arnd Bergmann

    Jan Blunck
     
  • 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

5 commits

  • Signed-off-by: Al Viro

    Al Viro
     
  • Copy and simplify in the only two users remaining.

    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
     
  • 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 cont_write_begin.

    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 prepearation of the new truncate calling sequence. This was only done
    for DIO_LOCKING filesystems, so the __blockdev_direct_IO_newtrunc variant
    was not needed anyway. Get rid of blockdev_direct_IO_no_locking and
    its _newtrunc variant while at it as just opencoding the two additional
    paramters is shorted than the name suffix.

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

    Christoph Hellwig
     

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
     

16 Dec, 2009

1 commit

  • A specially-crafted Hierarchical File System (HFS) filesystem could cause
    a buffer overflow to occur in a process's kernel stack during a memcpy()
    call within the hfs_bnode_read() function (at fs/hfs/bnode.c:24). The
    attacker can provide the source buffer and length, and the destination
    buffer is a local variable of a fixed length. This local variable (passed
    as "&entry" from fs/hfs/dir.c:112 and allocated on line 60) is stored in
    the stack frame of hfs_bnode_read()'s caller, which is hfs_readdir().
    Because the hfs_readdir() function executes upon any attempt to read a
    directory on the filesystem, it gets called whenever a user attempts to
    inspect any filesystem contents.

    [amwang@redhat.com: modify this patch and fix coding style problems]
    Signed-off-by: WANG Cong
    Cc: Eugene Teo
    Cc: Roman Zippel
    Cc: Al Viro
    Cc: Christoph Hellwig
    Cc: Alexey Dobriyan
    Cc: Dave Anderson
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Amerigo Wang
     

29 Oct, 2009

1 commit

  • A particular fsfuzzer run caused an hfs file system to crash on mount.
    This is due to a corrupted MDB extent record causing a miscalculation of
    HFS_I(inode)->first_blocks for the extent tree. If the extent records are
    zereod out, it won't trigger the first_blocks special case. Instead it
    falls through to the extent code which we're still in the middle of
    initializing.

    This patch catches the 0 size extent records, reports the corruption, and
    fails the mount.

    Reported-by: Ramon de Carvalho Valle
    Signed-off-by: Jeff Mahoney
    Cc: Valdis Kletnieks
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jeff Mahoney
     

24 Sep, 2009

1 commit

  • Most call sites of unload_nls() do:
    if (nls)
    unload_nls(nls);

    Check the pointer inside unload_nls() like we do in kfree() and
    simplify the call sites.

    Signed-off-by: Thomas Gleixner
    Cc: Steve French
    Cc: OGAWA Hirofumi
    Cc: Roman Zippel
    Cc: Dave Kleikamp
    Cc: Petr Vandrovec
    Cc: Anton Altaparmakov
    Signed-off-by: Al Viro

    Thomas Gleixner
     

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
     

12 Jun, 2009

4 commits

  • Add a ->sync_fs method for data integrity syncs.

    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
     

14 Apr, 2009

1 commit

  • When an HFS filesystem is unmounted, it leaks a 2-page bitmap. Also,
    under extreme memory pressure, it's possible that hfs_releasepage() may
    use a tree pointer that has not been initialized, and if so, the release
    request should just be rejected.

    [akpm@linux-foundation.org: free_pages(0) is legal, remove obvious comment]
    Signed-off-by: Dave Anderson
    Tested-by: Eugene Teo
    Cc: Roman Zippel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dave Anderson
     

03 Apr, 2009

1 commit


28 Mar, 2009

1 commit


22 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
    Cc: Roman Zippel
    Signed-off-by: James Morris

    David Howells
     

23 Oct, 2008

1 commit

  • For execute permission on a regular files we need to check if file has
    any execute bits at all, regardless of capabilites.

    This check is normally performed by generic_permission() but was also
    added to the case when the filesystem defines its own ->permission()
    method. In the latter case the filesystem should be responsible for
    performing this check.

    Move the check from inode_permission() inside filesystems which are
    not calling generic_permission().

    Create a helper function execute_ok() that returns true if the inode
    is a directory or if any execute bits are present in i_mode.

    Also fix up the following code:

    - coda control file is never executable
    - sysctl files are never executable
    - hfs_permission seems broken on MAY_EXEC, remove
    - hfsplus_permission is eqivalent to generic_permission(), remove

    Signed-off-by: Miklos Szeredi

    Miklos Szeredi
     

17 Oct, 2008

1 commit

  • Fix a stack corruption caused by a corrupted hfs filesystem. If the
    catalog name length is corrupted the memcpy overwrites the catalog btree
    structure. Since the field is limited to HFS_NAMELEN bytes in the
    structure and the file format, we throw an error if it is too long.

    Cc: Roman Zippel
    Signed-off-by: Eric Sesterhenn
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Eric Sesterhenn
     

14 Oct, 2008

1 commit

  • This is a much better version of a previous patch to make the parser
    tables constant. Rather than changing the typedef, we put the "const" in
    all the various places where its required, allowing the __initconst
    exception for nfsroot which was the cause of the previous trouble.

    This was posted for review some time ago and I believe its been in -mm
    since then.

    Signed-off-by: Steven Whitehouse
    Cc: Alexander Viro
    Signed-off-by: Linus Torvalds

    Steven Whitehouse
     

27 Jul, 2008

3 commits

  • make it atomic_long_t; while we are at it, get rid of useless checks in affs,
    hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0.

    Signed-off-by: Al Viro

    Al Viro
     
  • * kill nameidata * argument; map the 3 bits in ->flags anybody cares
    about to new MAY_... ones and pass with the mask.
    * kill redundant gfs2_iop_permission()
    * sanitize ecryptfs_permission()
    * fix remaining places where ->permission() instances might barf on new
    MAY_... found in mask.

    The obvious next target in that direction is permission(9)

    folded fix for nfs_permission() breakage from Miklos Szeredi

    Signed-off-by: Al Viro

    Al Viro
     
  • 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