linux-stable.git/fs/inode.c, branch v3.19 Linux kernel stable tree Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-16T23:53:03+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-12-16T23:53:03+00:00 603ba7e41bf5d405aba22294af5d075d8898176d Pull vfs pile #2 from Al Viro: "Next pile (and there'll be one or two more). The large piece in this one is getting rid of /proc/*/ns/* weirdness; among other things, it allows to (finally) make nameidata completely opaque outside of fs/namei.c, making for easier further cleanups in there" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: coda_venus_readdir(): use file_inode() fs/namei.c: fold link_path_walk() call into path_init() path_init(): don't bother with LOOKUP_PARENT in argument fs/namei.c: new helper (path_cleanup()) path_init(): store the "base" pointer to file in nameidata itself make default ->i_fop have ->open() fail with ENXIO make nameidata completely opaque outside of fs/namei.c kill proc_ns completely take the targets of /proc/*/ns/* symlinks to separate fs bury struct proc_ns in fs/proc copy address of proc_ns_ops into ns_common new helpers: ns_alloc_inum/ns_free_inum make proc_ns_operations work with struct ns_common * instead of void * switch the rest of proc_ns_operations to working with &...->ns netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns common object embedded into various struct ....ns 
Pull vfs pile #2 from Al Viro:
 "Next pile (and there'll be one or two more).

  The large piece in this one is getting rid of /proc/*/ns/* weirdness;
  among other things, it allows to (finally) make nameidata completely
  opaque outside of fs/namei.c, making for easier further cleanups in
  there"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coda_venus_readdir(): use file_inode()
  fs/namei.c: fold link_path_walk() call into path_init()
  path_init(): don't bother with LOOKUP_PARENT in argument
  fs/namei.c: new helper (path_cleanup())
  path_init(): store the "base" pointer to file in nameidata itself
  make default ->i_fop have ->open() fail with ENXIO
  make nameidata completely opaque outside of fs/namei.c
  kill proc_ns completely
  take the targets of /proc/*/ns/* symlinks to separate fs
  bury struct proc_ns in fs/proc
  copy address of proc_ns_ops into ns_common
  new helpers: ns_alloc_inum/ns_free_inum
  make proc_ns_operations work with struct ns_common * instead of void *
  switch the rest of proc_ns_operations to working with &...->ns
  netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
  make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
  common object embedded into various struct ....ns
mm: convert i_mmap_mutex to rwsem 2014-12-13T20:42:45+00:00 Davidlohr Bueso dave@stgolabs.net 2014-12-13T00:54:24+00:00 c8c06efa8b552608493b7066c234cfa82c47fcea The i_mmap_mutex is a close cousin of the anon vma lock, both protecting similar data, one for file backed pages and the other for anon memory. To this end, this lock can also be a rwsem. In addition, there are some important opportunities to share the lock when there are no tree modifications. This conversion is straightforward. For now, all users take the write lock. [sfr@canb.auug.org.au: update fremap.c] Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The i_mmap_mutex is a close cousin of the anon vma lock, both protecting
similar data, one for file backed pages and the other for anon memory.  To
this end, this lock can also be a rwsem.  In addition, there are some
important opportunities to share the lock when there are no tree
modifications.

This conversion is straightforward.  For now, all users take the write
lock.

[sfr@canb.auug.org.au: update fremap.c]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
make default ->i_fop have ->open() fail with ENXIO 2014-12-11T02:32:15+00:00 Al Viro viro@zeniv.linux.org.uk 2014-11-19T04:38:21+00:00 bd9b51e79cb0b8bc00a7e0076a4a8963ca4a797c As it is, default ->i_fop has NULL ->open() (along with all other methods). The only case where it matters is reopening (via procfs symlink) a file that didn't get its ->f_op from ->i_fop - anything else will have ->i_fop assigned to something sane (default would fail on read/write/ioctl/etc.). Unfortunately, such case exists - alloc_file() users, especially anon_get_file() ones. There we have tons of opened files of very different kinds sharing the same inode. As the result, attempt to reopen those via procfs succeeds and you get a descriptor you can't do anything with. Moreover, in case of sockets we set ->i_fop that will only be used on such reopen attempts - and put a failing ->open() into it to make sure those do not succeed. It would be simpler to put such ->open() into default ->i_fop and leave it unchanged both for anon inode (as we do anyway) and for socket ones. Result: * everything going through do_dentry_open() works as it used to * sock_no_open() kludge is gone * attempts to reopen anon-inode files fail as they really ought to * ditto for aio_private_file() * ditto for perfmon - this one actually tried to imitate sock_no_open() trick, but failed to set ->i_fop, so in the current tree reopens succeed and yield completely useless descriptor. Intent clearly had been to fail with -ENXIO on such reopens; now it actually does. * everything else that used alloc_file() keeps working - it has ->i_fop set for its inodes anyway Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
As it is, default ->i_fop has NULL ->open() (along with all other methods).
The only case where it matters is reopening (via procfs symlink) a file that
didn't get its ->f_op from ->i_fop - anything else will have ->i_fop assigned
to something sane (default would fail on read/write/ioctl/etc.).

	Unfortunately, such case exists - alloc_file() users, especially
anon_get_file() ones.  There we have tons of opened files of very different
kinds sharing the same inode.  As the result, attempt to reopen those via
procfs succeeds and you get a descriptor you can't do anything with.

	Moreover, in case of sockets we set ->i_fop that will only be used
on such reopen attempts - and put a failing ->open() into it to make sure
those do not succeed.

	It would be simpler to put such ->open() into default ->i_fop and leave
it unchanged both for anon inode (as we do anyway) and for socket ones.  Result:
	* everything going through do_dentry_open() works as it used to
	* sock_no_open() kludge is gone
	* attempts to reopen anon-inode files fail as they really ought to
	* ditto for aio_private_file()
	* ditto for perfmon - this one actually tried to imitate sock_no_open()
trick, but failed to set ->i_fop, so in the current tree reopens succeed and
yield completely useless descriptor.  Intent clearly had been to fail with
-ENXIO on such reopens; now it actually does.
	* everything else that used alloc_file() keeps working - it has ->i_fop
set for its inodes anyway

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
vfs: Remove i_dquot field from inode 2014-11-10T09:06:18+00:00 Jan Kara jack@suse.cz 2014-09-29T13:10:26+00:00 75cbe701a4251fcd8b846d52ae42f88c9a8e5e93 All filesystems using VFS quotas are now converted to use their private i_dquot fields. Remove the i_dquot field from generic inode structure. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> 
All filesystems using VFS quotas are now converted to use their private
i_dquot fields. Remove the i_dquot field from generic inode structure.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
mm: allow drivers to prevent new writable mappings 2014-08-08T22:57:31+00:00 David Herrmann dh.herrmann@gmail.com 2014-08-08T21:25:25+00:00 4bb5f5d9395bc112d93a134d8f5b05611eddc9c0 This patch (of 6): The i_mmap_writable field counts existing writable mappings of an address_space. To allow drivers to prevent new writable mappings, make this counter signed and prevent new writable mappings if it is negative. This is modelled after i_writecount and DENYWRITE. This will be required by the shmem-sealing infrastructure to prevent any new writable mappings after the WRITE seal has been set. In case there exists a writable mapping, this operation will fail with EBUSY. Note that we rely on the fact that iff you already own a writable mapping, you can increase the counter without using the helpers. This is the same that we do for i_writecount. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This patch (of 6):

The i_mmap_writable field counts existing writable mappings of an
address_space.  To allow drivers to prevent new writable mappings, make
this counter signed and prevent new writable mappings if it is negative.
This is modelled after i_writecount and DENYWRITE.

This will be required by the shmem-sealing infrastructure to prevent any
new writable mappings after the WRITE seal has been set.  In case there
exists a writable mapping, this operation will fail with EBUSY.

Note that we rely on the fact that iff you already own a writable mapping,
you can increase the counter without using the helpers.  This is the same
that we do for i_writecount.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ryan Lortie <desrt@desrt.ca>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Daniel Mack <zonque@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sched: Remove proliferation of wait_on_bit() action functions 2014-07-16T13:10:39+00:00 NeilBrown neilb@suse.de 2014-07-07T05:16:04+00:00 743162013d40ca612b4cb53d3a200dff2d9ab26e The current "wait_on_bit" interface requires an 'action' function to be provided which does the actual waiting. There are over 20 such functions, many of them identical. Most cases can be satisfied by one of just two functions, one which uses io_schedule() and one which just uses schedule(). So: Rename wait_on_bit and wait_on_bit_lock to wait_on_bit_action and wait_on_bit_lock_action to make it explicit that they need an action function. Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io which are *not* given an action function but implicitly use a standard one. The decision to error-out if a signal is pending is now made based on the 'mode' argument rather than being encoded in the action function. All instances of the old wait_on_bit and wait_on_bit_lock which can use the new version have been changed accordingly and their action functions have been discarded. wait_on_bit{_lock} does not return any specific error code in the event of a signal so the caller must check for non-zero and interpolate their own error code as appropriate. The wait_on_bit() call in __fscache_wait_on_invalidate() was ambiguous as it specified TASK_UNINTERRUPTIBLE but used fscache_wait_bit_interruptible as an action function. David Howells confirms this should be uniformly "uninterruptible" The main remaining user of wait_on_bit{,_lock}_action is NFS which needs to use a freezer-aware schedule() call. A comment in fs/gfs2/glock.c notes that having multiple 'action' functions is useful as they display differently in the 'wchan' field of 'ps'. (and /proc/$PID/wchan). As the new bit_wait{,_io} functions are tagged "__sched", they will not show up at all, but something higher in the stack. So the distinction will still be visible, only with different function names (gds2_glock_wait versus gfs2_glock_dq_wait in the gfs2/glock.c case). Since first version of this patch (against 3.15) two new action functions appeared, on in NFS and one in CIFS. CIFS also now uses an action function that makes the same freezer aware schedule call as NFS. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: David Howells <dhowells@redhat.com> (fscache, keys) Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2) Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown Signed-off-by: Ingo Molnar <mingo@kernel.org> 
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().

So:
 Rename wait_on_bit and        wait_on_bit_lock to
        wait_on_bit_action and wait_on_bit_lock_action
 to make it explicit that they need an action function.

 Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
 which are *not* given an action function but implicitly use
 a standard one.
 The decision to error-out if a signal is pending is now made
 based on the 'mode' argument rather than being encoded in the action
 function.

 All instances of the old wait_on_bit and wait_on_bit_lock which
 can use the new version have been changed accordingly and their
 action functions have been discarded.
 wait_on_bit{_lock} does not return any specific error code in the
 event of a signal so the caller must check for non-zero and
 interpolate their own error code as appropriate.

The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"

The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.

A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack.  So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).

Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS.  CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
fs,userns: Change inode_capable to capable_wrt_inode_uidgid 2014-06-10T20:57:22+00:00 Andy Lutomirski luto@amacapital.net 2014-06-10T19:45:42+00:00 23adbe12ef7d3d4195e80800ab36b37bee28cd03 The kernel has no concept of capabilities with respect to inodes; inodes exist independently of namespaces. For example, inode_capable(inode, CAP_LINUX_IMMUTABLE) would be nonsense. This patch changes inode_capable to check for uid and gid mappings and renames it to capable_wrt_inode_uidgid, which should make it more obvious what it does. Fixes CVE-2014-4014. Cc: Theodore Ts'o <tytso@mit.edu> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Chinner <david@fromorbit.com> Cc: stable@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The kernel has no concept of capabilities with respect to inodes; inodes
exist independently of namespaces.  For example, inode_capable(inode,
CAP_LINUX_IMMUTABLE) would be nonsense.

This patch changes inode_capable to check for uid and gid mappings and
renames it to capable_wrt_inode_uidgid, which should make it more
obvious what it does.

Fixes CVE-2014-4014.

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs: convert use of typedef ctl_table to struct ctl_table 2014-06-06T23:08:16+00:00 Joe Perches joe@perches.com 2014-06-06T21:38:05+00:00 1f7e0616cd4f5df594595153c3a01bbb16072380 This typedef is unnecessary and should just be removed. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This typedef is unnecessary and should just be removed.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2014-04-04T22:39:39+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-04-04T22:39:39+00:00 24e7ea3bea94fe05eae5019f5f12bcdc98fc5157 Pull ext4 updates from Ted Ts'o: "Major changes for 3.14 include support for the newly added ZERO_RANGE and COLLAPSE_RANGE fallocate operations, and scalability improvements in the jbd2 layer and in xattr handling when the extended attributes spill over into an external block. Other than that, the usual clean ups and minor bug fixes" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (42 commits) ext4: fix premature freeing of partial clusters split across leaf blocks ext4: remove unneeded test of ret variable ext4: fix comment typo ext4: make ext4_block_zero_page_range static ext4: atomically set inode->i_flags in ext4_set_inode_flags() ext4: optimize Hurd tests when reading/writing inodes ext4: kill i_version support for Hurd-castrated file systems ext4: each filesystem creates and uses its own mb_cache fs/mbcache.c: doucple the locking of local from global data fs/mbcache.c: change block and index hash chain to hlist_bl_node ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate ext4: refactor ext4_fallocate code ext4: Update inode i_size after the preallocation ext4: fix partial cluster handling for bigalloc file systems ext4: delete path dealloc code in ext4_ext_handle_uninitialized_extents ext4: only call sync_filesystm() when remounting read-only fs: push sync_filesystem() down to the file system's remount_fs() jbd2: improve error messages for inconsistent journal heads jbd2: minimize region locked by j_list_lock in jbd2_journal_forget() jbd2: minimize region locked by j_list_lock in journal_get_create_access() ... 
Pull ext4 updates from Ted Ts'o:
 "Major changes for 3.14 include support for the newly added ZERO_RANGE
  and COLLAPSE_RANGE fallocate operations, and scalability improvements
  in the jbd2 layer and in xattr handling when the extended attributes
  spill over into an external block.

  Other than that, the usual clean ups and minor bug fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (42 commits)
  ext4: fix premature freeing of partial clusters split across leaf blocks
  ext4: remove unneeded test of ret variable
  ext4: fix comment typo
  ext4: make ext4_block_zero_page_range static
  ext4: atomically set inode->i_flags in ext4_set_inode_flags()
  ext4: optimize Hurd tests when reading/writing inodes
  ext4: kill i_version support for Hurd-castrated file systems
  ext4: each filesystem creates and uses its own mb_cache
  fs/mbcache.c: doucple the locking of local from global data
  fs/mbcache.c: change block and index hash chain to hlist_bl_node
  ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate
  ext4: refactor ext4_fallocate code
  ext4: Update inode i_size after the preallocation
  ext4: fix partial cluster handling for bigalloc file systems
  ext4: delete path dealloc code in ext4_ext_handle_uninitialized_extents
  ext4: only call sync_filesystm() when remounting read-only
  fs: push sync_filesystem() down to the file system's remount_fs()
  jbd2: improve error messages for inconsistent journal heads
  jbd2: minimize region locked by j_list_lock in jbd2_journal_forget()
  jbd2: minimize region locked by j_list_lock in journal_get_create_access()
  ...
Merge branch 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2014-04-04T21:03:05+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-04-04T21:03:05+00:00 7df934526c0b3775613502dcd19ab6d2da8cce1e Pull renameat2 system call from Miklos Szeredi: "This adds a new syscall, renameat2(), which is the same as renameat() but with a flags argument. The purpose of extending rename is to add cross-rename, a symmetric variant of rename, which exchanges the two files. This allows interesting things, which were not possible before, for example atomically replacing a directory tree with a symlink, etc... This also allows overlayfs and friends to operate on whiteouts atomically. Andy Lutomirski also suggested a "noreplace" flag, which disables the overwriting behavior of rename. These two flags, RENAME_EXCHANGE and RENAME_NOREPLACE are only implemented for ext4 as an example and for testing" * 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ext4: add cross rename support ext4: rename: split out helper functions ext4: rename: move EMLINK check up ext4: rename: create ext4_renament structure for local vars vfs: add cross-rename vfs: lock_two_nondirectories: allow directory args security: add flags to rename hooks vfs: add RENAME_NOREPLACE flag vfs: add renameat2 syscall vfs: rename: use common code for dir and non-dir vfs: rename: move d_move() up vfs: add d_is_dir() 
Pull renameat2 system call from Miklos Szeredi:
 "This adds a new syscall, renameat2(), which is the same as renameat()
  but with a flags argument.

  The purpose of extending rename is to add cross-rename, a symmetric
  variant of rename, which exchanges the two files.  This allows
  interesting things, which were not possible before, for example
  atomically replacing a directory tree with a symlink, etc...  This
  also allows overlayfs and friends to operate on whiteouts atomically.

  Andy Lutomirski also suggested a "noreplace" flag, which disables the
  overwriting behavior of rename.

  These two flags, RENAME_EXCHANGE and RENAME_NOREPLACE are only
  implemented for ext4 as an example and for testing"

* 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ext4: add cross rename support
  ext4: rename: split out helper functions
  ext4: rename: move EMLINK check up
  ext4: rename: create ext4_renament structure for local vars
  vfs: add cross-rename
  vfs: lock_two_nondirectories: allow directory args
  security: add flags to rename hooks
  vfs: add RENAME_NOREPLACE flag
  vfs: add renameat2 syscall
  vfs: rename: use common code for dir and non-dir
  vfs: rename: move d_move() up
  vfs: add d_is_dir()