hashed dentry can be passed to ->atomic_open() only if
a) it has just passed revalidation and
b) it's negative
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

return dentry, not inode.  dev->inode is never used by anything,
don't bother with storing it.
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

make it return dentry instead of inode
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

hlist_add_fake(inode->i_hash), same as for the rest of special ones...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The only way we can get to that function is from misc_open(), after
the latter has set file->f_op to exactly the same value we are
(re)assigning there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The gcc version 4.9.1 compiler complains Even though it isn't possible for
these variables to not get initialized before they are used.

fs/namespace.c: In function ‘SyS_mount’:
fs/namespace.c:2720:8: warning: ‘kernel_dev’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  ret = do_mount(kernel_dev, kernel_dir->name, kernel_type, flags,
        ^
fs/namespace.c:2699:8: note: ‘kernel_dev’ was declared here
  char *kernel_dev;
        ^
fs/namespace.c:2720:8: warning: ‘kernel_type’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  ret = do_mount(kernel_dev, kernel_dir->name, kernel_type, flags,
        ^
fs/namespace.c:2697:8: note: ‘kernel_type’ was declared here
  char *kernel_type;
        ^

Fix the warnings by simplifying copy_mount_string() as suggested by Al Viro.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

That loop in there is both anti-idiomatic *and* completely pointless.
strtoll() is there for purpose; use it and compare what's left with
acceptable suffices.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

... not to mention that even atomic_long_read() is too low-level here -
there's file_count().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

check with the author of that horror...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This patch makes it possible to kill a process looping in
cont_expand_zero. A process may spend a lot of time in this function, so
it is desirable to be able to kill it.

It happened to me that I wanted to copy a piece data from the disk to a
file. By mistake, I used the "seek" parameter to dd instead of "skip". Due
to the "seek" parameter, dd attempted to extend the file and became stuck
doing so - the only possibility was to reset the machine or wait many
hours until the filesystem runs out of space and cont_expand_zero fails.
We need this patch to be able to terminate the process.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

For DAX, we want to be able to copy between iovecs and kernel addresses
that don't necessarily have a struct page.  This is a fairly simple
rearrangement for bvec iters to kmap the pages outside and pass them in,
but for user iovecs it gets more complicated because we might try various
different ways to kmap the memory.  Duplicating the existing logic works
out best in this case.

We need to be able to write zeroes to an iovec for reads from unwritten
ranges in a file.  This is performed by the new iov_iter_zero() function,
again patterned after the existing code that handles iovec iterators.

[AV: and export the buggers...]
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

total_objects could be 0 and is used as a denom.

While total_objects is a "long", total_objects == 0 unlikely happens for
3.12 and later kernels because 32-bit architectures would not be able to
hold (1 << 32) objects. However, total_objects == 0 may happen for kernels
between 3.1 and 3.11 because total_objects in prune_super() was an "int"
and (e.g.) x86_64 architecture might be able to hold (1 << 32) objects.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable <stable@kernel.org> # 3.1+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Fixed coding style in dcache.c
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

schedule_delayed_work() happening when the work is already pending is
a cheap no-op.  Don't bother with ->wbuf_queued logics - it's both
broken (cancelling ->wbuf_dwork leaves it set, as spotted by Jeff Harris)
and pointless.  It's cheaper to let schedule_delayed_work() handle that
case.
Reported-by: Jeff Harris <jefftharris@gmail.com>
Tested-by: Jeff Harris <jefftharris@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The function which calls s_op->alloc_inode() is not inode_alloc(), but
instead alloc_inode() which lives in fs/inode.c .

The typo was there from the beginning from 5ea626aa (VFS: update
documentation, 2005) - there was no standalone inode_alloc() for the
whole kernel history.

Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

... rather than doing that in the guts of ->load_binary().
[updated to fix the bug spotted by Shentino - for SIGSEGV we really need
something stronger than send_sig_info(); again, better do that in one place]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

the only in-tree instance checks d_unhashed() anyway,
out-of-tree code can preserve the current behaviour by
adding such check if they want it and we get an ability
to use it in cases where we *want* to be notified of
killing being inevitable before ->d_lock is dropped,
whether it's unhashed or not.  In particular, autofs
would benefit from that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The only reason for games with ->d_prune() was __d_drop(), which
was needed only to force dput() into killing the sucker off.

Note that lock_parent() can be called under ->i_lock and won't
drop it, so dentry is safe from somebody managing to kill it
under us - it won't happen while we are holding ->i_lock.

__dentry_kill() is called only with ->d_lockref.count being 0
(here and when picked from shrink list) or 1 (dput() and dropping
the ancestors in shrink_dentry_list()), so it will never be called
twice - the first thing it's doing is making ->d_lockref.count
negative and once that happens, nothing will increment it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Now that d_invalidate always succeeds and flushes mount points use
it in stead of a combination of shrink_dcache_parent and d_drop
in proc_flush_task_mnt.  This removes the danger of a mount point
under /proc/<pid>/... becoming unreachable after the d_drop.
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Now that d_invalidate always succeeds it is not longer necessary or
desirable to hard code d_drop calls into filesystem specific
d_revalidate implementations.

Remove the unnecessary d_drop calls and rely on d_invalidate
to drop the dentries.  Using d_invalidate ensures that paths
to mount points will not be dropped.
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Now that d_invalidate can no longer fail, stop returning a useless
return code.  For the few callers that checked the return code update
remove the handling of d_invalidate failure.
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Now that d_invalidate is the only caller of check_submounts_and_drop,
expand check_submounts_and_drop inline in d_invalidate.
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Now that check_submounts_and_drop can not fail and is called from
d_invalidate there is no longer a need to call check_submounts_and_drom
from filesystem d_revalidate methods so remove it.
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>