Eric Lee / smarc-ti-linux-kernel

27 Sep, 2012

1 commit

02 Aug, 2012

1 commit

  • a0e881b7c   Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs ... Browse Code »

    Pull second vfs pile from Al Viro:
    "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
    deadlock reproduced by xfstests 068), symlink and hardlink restriction
    patches, plus assorted cleanups and fixes.

    Note that another fsfreeze deadlock (emergency thaw one) is *not*
    dealt with - the series by Fernando conflicts a lot with Jan's, breaks
    userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
    for massive vfsmount leak; this is going to be handled next cycle.
    There probably will be another pull request, but that stuff won't be
    in it."

    Fix up trivial conflicts due to unrelated changes next to each other in
    drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
    delousing target_core_file a bit
    Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
    fs: Remove old freezing mechanism
    ext2: Implement freezing
    btrfs: Convert to new freezing mechanism
    nilfs2: Convert to new freezing mechanism
    ntfs: Convert to new freezing mechanism
    fuse: Convert to new freezing mechanism
    gfs2: Convert to new freezing mechanism
    ocfs2: Convert to new freezing mechanism
    xfs: Convert to new freezing code
    ext4: Convert to new freezing mechanism
    fs: Protect write paths by sb_start_write - sb_end_write
    fs: Skip atime update on frozen filesystem
    fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
    fs: Improve filesystem freezing handling
    switch the protection of percpu_counter list to spinlock
    nfsd: Push mnt_want_write() outside of i_mutex
    btrfs: Push mnt_want_write() outside of i_mutex
    fat: Push mnt_want_write() outside of i_mutex
    ...

    Linus Torvalds
     

30 Jul, 2012

1 commit

24 Jul, 2012

1 commit

02 Jun, 2012

1 commit

  • c3b2da314   fs: introduce inode operation ->update_time ... Browse Code »

    Btrfs has to make sure we have space to allocate new blocks in order to modify
    the inode, so updating time can fail. We've gotten around this by having our
    own file_update_time but this is kind of a pain, and Christoph has indicated he
    would like to make xfs do something different with atime updates. So introduce
    ->update_time, where we will deal with i_version an a/m/c time updates and
    indicate which changes need to be made. The normal version just does what it
    has always done, updates the time and marks the inode dirty, and then
    filesystems can choose to do something different.

    I've gone through all of the users of file_update_time and made them check for
    errors with the exception of the fault code since it's complicated and I wasn't
    quite sure what to do there, also Jan is going to be pushing the file time
    updates into page_mkwrite for those who have it so that should satisfy btrfs and
    make it not a big deal to check the file_update_time() return code in the
    generic fault path. Thanks,

    Signed-off-by: Josef Bacik

    Josef Bacik
     

31 May, 2012

1 commit

  • 46ce341b2   pipe: return -ENOIOCTLCMD instead of -EINVAL on unknown ioctl command ... Browse Code »

    As described in commit 07d106d0a ("vfs: fix up ENOIOCTLCMD error
    handling"), drivers should return -ENOIOCTLCMD if they receive an ioctl
    command which they don't understand. Doing so will result in -ENOTTY
    being returned to userspace, which matches the behaviour of the compat
    layer if it fails to translate an ioctl command.

    This patch fixes the pipe ioctl to return -ENOIOCTLCMD instead of
    -EINVAL when passed an unknown ioctl command.

    Cc: Al Viro
    Cc: Andrew Morton
    Signed-off-by: Will Deacon
    Signed-off-by: Al Viro

    Will Deacon
     

30 Apr, 2012

1 commit

  • 9883035ae   pipes: add a "packetized pipe" mode for writing ... Browse Code »

    The actual internal pipe implementation is already really about
    individual packets (called "pipe buffers"), and this simply exposes that
    as a special packetized mode.

    When we are in the packetized mode (marked by O_DIRECT as suggested by
    Alan Cox), a write() on a pipe will not merge the new data with previous
    writes, so each write will get a pipe buffer of its own. The pipe
    buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn
    will tell the reader side to break the read at that boundary (and throw
    away any partial packet contents that do not fit in the read buffer).

    End result: as long as you do writes less than PIPE_BUF in size (so that
    the pipe doesn't have to split them up), you can now treat the pipe as a
    packet interface, where each read() system call will read one packet at
    a time. You can just use a sufficiently big read buffer (PIPE_BUF is
    sufficient, since bigger than that doesn't guarantee atomicity anyway),
    and the return value of the read() will naturally give you the size of
    the packet.

    NOTE! We do not support zero-sized packets, and zero-sized reads and
    writes to a pipe continue to be no-ops. Also note that big packets will
    currently be split at write time, but that the size at which that
    happens is not really specified (except that it's bigger than PIPE_BUF).
    Currently that limit is the system page size, but we might want to
    explicitly support bigger packets some day.

    The main user for this is going to be the autofs packet interface,
    allowing us to stop having to care so deeply about exact packet sizes
    (which have had bugs with 32/64-bit compatibility modes). But user
    space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will
    fail with an EINVAL on kernels that do not support this interface.

    Tested-by: Michael Tokarev
    Cc: Alan Cox
    Cc: David Miller
    Cc: Ian Kent
    Cc: Thomas Meyer
    Cc: stable@kernel.org # needed for systemd/autofs interaction fix
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

24 Mar, 2012

1 commit

20 Mar, 2012

1 commit

13 Jan, 2012

1 commit

  • 2ccd4f4d4   pipe: fail cleanly when root tries F_SETPIPE_SZ with big size ... Browse Code »

    When a user with the CAP_SYS_RESOURCE cap tries to F_SETPIPE_SZ a pipe
    with size bigger than kmalloc() can alloc it spits out an ugly warning:

    ------------[ cut here ]------------
    WARNING: at mm/page_alloc.c:2095 __alloc_pages_nodemask+0x5d3/0x7a0()
    Pid: 733, comm: a.out Not tainted 3.2.0-rc1+ #4
    Call Trace:
    warn_slowpath_common+0x75/0xb0
    warn_slowpath_null+0x15/0x20
    __alloc_pages_nodemask+0x5d3/0x7a0
    __get_free_pages+0x12/0x50
    __kmalloc+0x12b/0x150
    pipe_set_size+0x75/0x120
    pipe_fcntl+0xf8/0x140
    do_fcntl+0x2d4/0x410
    sys_fcntl+0x66/0xa0
    system_call_fastpath+0x16/0x1b
    ---[ end trace 432f702e6db7b5ee ]---

    Instead, make kcalloc() handle the overflow case and fail quietly.

    [akpm@linux-foundation.org: switch to sizeof(*bufs) for 80-column niceness]
    Signed-off-by: Sasha Levin
    Cc: Alexander Viro
    Acked-by: Pekka Enberg
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Sasha Levin
     

04 Jan, 2012

1 commit

01 Nov, 2011

1 commit

  • d70ef97ba   fs/pipe.c: add ->statfs callback for pipefs ... Browse Code »

    Currently a statfs on a pipe's /proc//fd/ link returns -ENOSYS. Wire
    pipfs up so that the statfs succeeds.

    This is required by checkpoint-restart in the userspace to make it
    possible to distinguish pipes from fifos.

    When we dump information about task's open files we use the /proc/pid/fd
    directoy's symlinks and the fact that opening any of them gives us exactly
    the same dentry->inode pair as the original process has. Now if a task
    we're dumping has opened pipe and fifo we need to detect this and act
    accordingly. Knowing that an fd with type S_ISFIFO resides on a pipefs is
    the most precise way.

    Signed-off-by: Pavel Emelyanov
    Reviewed-by: Tejun Heo
    Acked-by: Serge Hallyn
    Signed-off-by: Cyrill Gorcunov
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Pavel Emelyanov
     

27 Jul, 2011

1 commit

24 Jul, 2011

1 commit

  • 423e0ab08   VFS : mount lock scalability for internal mounts ... Browse Code »

    For a number of file systems that don't have a mount point (e.g. sockfs
    and pipefs), they are not marked as long term. Therefore in
    mntput_no_expire, all locks in vfs_mount lock are taken instead of just
    local cpu's lock to aggregate reference counts when we release
    reference to file objects. In fact, only local lock need to have been
    taken to update ref counts as these file systems are in no danger of
    going away until we are ready to unregister them.

    The attached patch marks file systems using kern_mount without
    mount point as long term. The contentions of vfs_mount lock
    is now eliminated. Before un-registering such file system,
    kern_unmount should be called to remove the long term flag and
    make the mount point ready to be freed.

    Signed-off-by: Tim Chen
    Signed-off-by: Al Viro

    Tim Chen
     

21 Jan, 2011

1 commit

  • 28e58ee8c   Fix broken "pipe: use event aware wakeups" optimization ... Browse Code »

    Commit e462c448fdc8 ("pipe: use event aware wakeups") optimized the pipe
    event wakeup calls to avoid wakeups if the events do not match the
    requested set.

    However, the optimization was buggy, in that it didn't actually use the
    correct sets for the events: when we make room for more data to be
    written, the pipe poll() routine will return both the POLLOUT _and_
    POLLWRNORM bits. Similarly for read.

    And most critically, when a pipe is released, that will potentially
    result in POLLHUP|POLLERR (depending on whether it was the last reader
    or writer), not just the regular POLLIN|POLLOUT.

    This bug showed itself as a hung gnome-screensaver-dialog process, stuck
    forever (or at least until it was poked by a signal or by being traced)
    in a poll() system call.

    Cc: Davide Libenzi
    Cc: David S. Miller
    Cc: Eric Dumazet
    Cc: Jens Axboe
    Cc: Andrew Morton
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

17 Jan, 2011

1 commit

  • f03c65993   sanitize vfsmount refcounting changes ... Browse Code »

    Instead of splitting refcount between (per-cpu) mnt_count
    and (SMP-only) mnt_longrefs, make all references contribute
    to mnt_count again and keep track of how many are longterm
    ones.

    Accounting rules for longterm count:
    * 1 for each fs_struct.root.mnt
    * 1 for each fs_struct.pwd.mnt
    * 1 for having non-NULL ->mnt_ns
    * decrement to 0 happens only under vfsmount lock exclusive

    That allows nice common case for mntput() - since we can't drop the
    final reference until after mnt_longterm has reached 0 due to the rules
    above, mntput() can grab vfsmount lock shared and check mnt_longterm.
    If it turns out to be non-zero (which is the common case), we know
    that this is not the final mntput() and can just blindly decrement
    percpu mnt_count. Otherwise we grab vfsmount lock exclusive and
    do usual decrement-and-check of percpu mnt_count.

    For fs_struct.c we have mnt_make_longterm() and mnt_make_shortterm();
    namespace.c uses the latter in places where we don't already hold
    vfsmount lock exclusive and opencodes a few remaining spots where
    we need to manipulate mnt_longterm.

    Note that we mostly revert the code outside of fs/namespace.c back
    to what we used to have; in particular, normal code doesn't need
    to care about two kinds of references, etc. And we get to keep
    the optimization Nick's variant had bought us...

    Signed-off-by: Al Viro

    Al Viro
     

14 Jan, 2011

2 commits

  • b2034d474   Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 ... Browse Code »

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (41 commits)
    fs: add documentation on fallocate hole punching
    Gfs2: fail if we try to use hole punch
    Btrfs: fail if we try to use hole punch
    Ext4: fail if we try to use hole punch
    Ocfs2: handle hole punching via fallocate properly
    XFS: handle hole punching via fallocate properly
    fs: add hole punching to fallocate
    vfs: pass struct file to do_truncate on O_TRUNC opens (try #2)
    fix signedness mess in rw_verify_area() on 64bit architectures
    fs: fix kernel-doc for dcache::prepend_path
    fs: fix kernel-doc for dcache::d_validate
    sanitize ecryptfs ->mount()
    switch afs
    move internal-only parts of ncpfs headers to fs/ncpfs
    switch ncpfs
    switch 9p
    pass default dentry_operations to mount_pseudo()
    switch hostfs
    switch affs
    switch configfs
    ...

    Linus Torvalds
     
  • e462c448f   pipe: use event aware wakeups ... Browse Code »

    Send the events the wakeup refers to, so that epoll, and even the new poll
    code in fs/select.c can avoid wakeups if the events do not match the
    requested set.

    Signed-off-by: Davide Libenzi
    Acked-by: David S. Miller
    Acked-by: Eric Dumazet
    Cc: Jens Axboe
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davide Libenzi
     

13 Jan, 2011

1 commit

07 Jan, 2011

4 commits

  • b3e19d924   fs: scale mntget/mntput ... Browse Code »

    The problem that this patch aims to fix is vfsmount refcounting scalability.
    We need to take a reference on the vfsmount for every successful path lookup,
    which often go to the same mount point.

    The fundamental difficulty is that a "simple" reference count can never be made
    scalable, because any time a reference is dropped, we must check whether that
    was the last reference. To do that requires communication with all other CPUs
    that may have taken a reference count.

    We can make refcounts more scalable in a couple of ways, involving keeping
    distributed counters, and checking for the global-zero condition less
    frequently.

    - check the global sum once every interval (this will delay zero detection
    for some interval, so it's probably a showstopper for vfsmounts).

    - keep a local count and only taking the global sum when local reaches 0 (this
    is difficult for vfsmounts, because we can't hold preempt off for the life of
    a reference, so a counter would need to be per-thread or tied strongly to a
    particular CPU which requires more locking).

    - keep a local difference of increments and decrements, which allows us to sum
    the total difference and hence find the refcount when summing all CPUs. Then,
    keep a single integer "long" refcount for slow and long lasting references,
    and only take the global sum of local counters when the long refcount is 0.

    This last scheme is what I implemented here. Attached mounts and process root
    and working directory references are "long" references, and everything else is
    a short reference.

    This allows scalable vfsmount references during path walking over mounted
    subtrees and unattached (lazy umounted) mounts with processes still running
    in them.

    This results in one fewer atomic op in the fastpath: mntget is now just a
    per-CPU inc, rather than an atomic inc; and mntput just requires a spinlock
    and non-atomic decrement in the common case. However code is otherwise bigger
    and heavier, so single threaded performance is basically a wash.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • 4b936885a   fs: improve scalability of pseudo filesystems ... Browse Code »

    Regardless of how much we possibly try to scale dcache, there is likely
    always going to be some fundamental contention when adding or removing children
    under the same parent. Pseudo filesystems do not seem need to have connected
    dentries because by definition they are disconnected.

    Signed-off-by: Nick Piggin

    Nick Piggin
     
  • fb045adb9   fs: dcache reduce branches in lookup path ... Browse Code »

    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
     
  • ff0c7d15f   fs: avoid inode RCU freeing for pseudo fs ... Browse Code »

    Pseudo filesystems that don't put inode on RCU list or reachable by
    rcu-walk dentries do not need to RCU free their inodes.

    Signed-off-by: Nick Piggin

    Nick Piggin
     

29 Nov, 2010

2 commits

  • 720836465   Un-inline get_pipe_info() helper function ... Browse Code »

    This avoids some include-file hell, and the function isn't really
    important enough to be inlined anyway.

    Reported-by: Ingo Molnar
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     
  • c66fb3479   Export 'get_pipe_info()' to other users ... Browse Code »

    And in particular, use it in 'pipe_fcntl()'.

    The other pipe functions do not need to use the 'careful' version, since
    they are only ever called for things that are already known to be pipes.

    The normal read/write/ioctl functions are called through the file
    operations structures, so if a file isn't a pipe, they'd never get
    called. But pipe_fcntl() is special, and called directly from the
    generic fcntl code, and needs to use the same careful function that the
    splice code is using.

    Cc: Jens Axboe
    Cc: Andrew Morton
    Cc: Al Viro
    Cc: Dave Jones
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

29 Oct, 2010

1 commit

26 Oct, 2010

1 commit

  • 85fe4025c   fs: do not assign default i_ino in new_inode ... Browse Code »

    Instead of always assigning an increasing inode number in new_inode
    move the call to assign it into those callers that actually need it.
    For now callers that need it is estimated conservatively, that is
    the call is added to all filesystems that do not assign an i_ino
    by themselves. For a few more filesystems we can avoid assigning
    any inode number given that they aren't user visible, and for others
    it could be done lazily when an inode number is actually needed,
    but that's left for later patches.

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

    Christoph Hellwig
     

21 Oct, 2010

1 commit

11 Jun, 2010

2 commits

  • 6db40cf04   pipe: fix check in "set size" fcntl ... Browse Code »

    As it stands this check compares the number of pages to the page size.
    This makes no sense and makes the fcntl fail in almost any sane case.

    Fix it by checking if nr_pages is not zero (it can become zero only if
    arg is too big and round_pipe_size() overflows).

    Signed-off-by: Miklos Szeredi
    Signed-off-by: Jens Axboe

    Miklos Szeredi
     
  • 1d862f412   pipe: fix pipe buffer resizing ... Browse Code »

    pipe_set_size() needs to copy pipe bufs from the old circular buffer
    to the new.

    The current code gets this wrong in multiple ways, resulting in oops.

    Test program is available here:
    http://www.kernel.org/pub/linux/kernel/people/mszeredi/piperesize/

    Signed-off-by: Miklos Szeredi
    Signed-off-by: Jens Axboe

    Miklos Szeredi
     

03 Jun, 2010

3 commits

01 Jun, 2010

1 commit

31 May, 2010

1 commit

28 May, 2010

1 commit

  • cc967be54   fs: Add missing mutex_unlock ... Browse Code »

    Add a mutex_unlock missing on the error path. At other exists from the
    function that return an error flag, the mutex is unlocked, so do the same
    here.

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

    //
    @@
    expression E1;
    @@

    * mutex_lock(E1,...);

    * mutex_unlock(E1,...);
    //

    Signed-off-by: Julia Lawall
    Signed-off-by: Al Viro

    Julia Lawall
     

26 May, 2010

1 commit

25 May, 2010

2 commits

22 May, 2010

1 commit