->permission() sanitizing: don't pass flags to ->permission()

not used by the instances anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
->permission() sanitizing: don't pass flags to
 exec_permission()

pass mask instead; kill security_inode_exec_permission() since we can use
security_inode_permission() instead.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
modified by faux123 for Linux 3.0.x
massage generic_permission() to treat directories on a separate path

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
no reason to keep exec_permission() separate now

cache footprint alone makes it a bad idea...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
merge do_revalidate() into its only caller

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Don't pass nameidata when calling vfs_create() from mknod()

All instances can cope with that now (and ceph one actually
starts working properly).

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

new helper: would_dump(bprm, file).  Checks if we are allowed to
read the file and if we are not - sets ENFORCE_NODUMP.  Exported,
used in places that previously open-coded the same logics.

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

Commit a9ff4f87 "fuse: support BSD locking semantics" overlooked a
number of issues with supporing flock locks over existing POSIX
locking infrastructure:

  - it's not backward compatible, passing flock(2) calls to userspace
    unconditionally (if userspace sets FUSE_POSIX_LOCKS)

  - it doesn't cater for the fact that flock locks are automatically
    unlocked on file release

  - it doesn't take into account the fact that flock exclusive locks
    (write locks) don't need an fd opened for write.

The last one invalidates the original premise of the patch that flock
locks can be emulated with POSIX locks.

This patch fixes the first two issues.  The last one needs to be fixed
in userspace if the filesystem assumed that a write lock will happen
only on a file operned for write (as in the case of the current fuse
library).

Reported-by: Sebastian Pipping <webmaster@hartwork.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: delete dead .write_begin and .write_end aops

Ever since 'ea9b990 fuse: implement perform_write', the .write_begin
and .write_end aops have been dead code.

Their task - acquiring a page from the page cache, sending out a write
request and releasing the page again - is now done batch-wise to
maximize the number of pages send per userspace request.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: mark pages accessed when written to

As fuse does not use the page cache library functions when userspace
writes to a file, it did not benefit from 'c8236db mm: mark page
accessed before we write_end()' that made sure pages are properly
marked accessed when written to.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: fix flock breakage

Commit 37fb3a30b4 ("fuse: fix flock") added in 3.1-rc4 caused flock() to
fail with ENOSYS with the kernel ABI version 7.16 or earlier.

Fix by falling back to testing FUSE_POSIX_LOCKS for ABI versions 7.16
and earlier.

Reported-by: Martin Ziegler <ziegler@email.mathematik.uni-freiburg.de>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Martin Ziegler <ziegler@email.mathematik.uni-freiburg.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fuse: fix llseek bug

The test in fuse_file_llseek() "not SEEK_CUR or not SEEK_SET" always evaluates
to true.

This was introduced in 3.1 by commit 06222e49 (fs: handle SEEK_HOLE/SEEK_DATA
properly in all fs's that define their own llseek) and changed the behavior of
SEEK_CUR and SEEK_SET to always retrieve the file attributes.  This is a
performance regression.

Fix the test so that it makes sense.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@vger.kernel.org
CC: Josef Bacik <josef@redhat.com>
CC: Al Viro <viro@zeniv.linux.org.uk>
fuse: llseek fix race

Fix race between lseek(fd, 0, SEEK_CUR) and read/write.  This was fixed in
generic code by commit 5b6f1eb97d (vfs: lseek(fd, 0, SEEK_CUR) race condition).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: llseek optimize SEEK_CUR and SEEK_SET

Use generic_file_llseek() instead of open coding the seek function.

i_mutex protection is only necessary for SEEK_END (and SEEK_HOLE, SEEK_DATA), so
move SEEK_CUR and SEEK_SET out from under i_mutex.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: Use kcalloc instead of kzalloc to allocate array

The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: support ioctl on directories

Multiplexing filesystems may want to support ioctls on the underlying
files and directores (e.g. FS_IOC_{GET,SET}FLAGS).

Ioctl support on directories was missing so add it now.

Reported-by: Antonio SJ Musumeci <bile@landofbile.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
FUSE: Notifying the kernel of deletion.

Allows a FUSE file-system to tell the kernel when a file or directory is
deleted. If the specified dentry has the specified inode number, the kernel will
unhash it.

The current 'fuse_notify_inval_entry' does not cause the kernel to clean up
directories that are in use properly, and as a result the users of those
directories see incorrect semantics from the file-system. The error condition
seen when 'fuse_notify_inval_entry' is used to notify of a deleted directory is
avoided when 'fuse_notify_delete' is used instead.

The following scenario demonstrates the difference:
1. User A chdirs into 'testdir' and starts reading 'testfile'.
2. User B rm -rf 'testdir'.
3. User B creates 'testdir'.
4. User C chdirs into 'testdir'.

If you run the above within the same machine on any file-system (including fuse
file-systems), there is no problem: user C is able to chdir into the new
testdir. The old testdir is removed from the dentry tree, but still open by user
A.

If operations 2 and 3 are performed via the network such that the fuse
file-system uses one of the notify functions to tell the kernel that the nodes
are gone, then the following error occurs for user C while user A holds the
original directory open:

muirj@empacher:~> ls /test/testdir
ls: cannot access /test/testdir: No such file or directory

The issue here is that the kernel still has a dentry for testdir, and so it is
requesting the attributes for the old directory, while the file-system is
responding that the directory no longer exists.

If on the other hand, if the file-system can notify the kernel that the
directory is deleted using the new 'fuse_notify_delete' function, then the above
ls will find the new directory as expected.

Signed-off-by: John Muir <john@jmuir.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: register_filesystem() called too early

same story as with ubifs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs: simplify the blockdev_direct_IO prototype

Simple filesystems always pass inode->i_sb_bdev as the block device
argument, and never need a end_io handler.  Let's simply things for
them and for my grepping activity by dropping these arguments.  The
only thing not falling into that scheme is ext4, which passes and
end_io handler without needing special flags (yet), but given how
messy the direct I/O code there is use of __blockdev_direct_IO
in one instead of two out of three cases isn't going to make a large
difference anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Conflicts:
	fs/ext4/inode.c
ext4: fix data corruption in inodes with journalled data

When journalling data for an inode (either because it is a symlink or
because the filesystem is mounted in data=journal mode), ext4_evict_inode()
can discard unwritten data by calling truncate_inode_pages(). This is
because we don't mark the buffer / page dirty when journalling data but only
add the buffer to the running transaction and thus mm does not know there
are still unwritten data.

Fix the problem by carefully tracking transaction containing inode's data,
committing this transaction, and writing uncheckpointed buffers when inode
should be reaped.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>