clean up some unused functions and parameters.

Link: http://lkml.kernel.org/r/598A5E21.2080807@huawei.comSigned-off-by: NJun Piao <piaojun@huawei.com>
Reviewed-by: NAlex Chen <alex.chen@huawei.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Strengthen the checking of pos/len vs. i_size, clarify the return values
for the clone prep function, and remove pointless code.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

In ocfs2_lock_refcount_tree, if ocfs2_read_refcount_block() returns an
error, we do ocfs2_refcount_tree_put twice (once in
ocfs2_unlock_refcount_tree and once outside it), thereby reducing the
refcount of the refcount tree twice, but we dont delete the tree in this
case.  This will make refcnt of the tree = 0 and the
ocfs2_refcount_tree_put will eventually call ocfs2_mark_lockres_freeing,
setting OCFS2_LOCK_FREEING for the refcount_tree->rf_lockres.

The error returned by ocfs2_read_refcount_block is propagated all the
way back and for next iteration of write, ocfs2_lock_refcount_tree gets
the same tree back from ocfs2_get_refcount_tree because we havent
deleted the tree.  Now we have the same tree, but OCFS2_LOCK_FREEING is
set for rf_lockres and eventually, when _ocfs2_lock_refcount_tree is
called in this iteration, BUG_ON( __ocfs2_cluster_lock:1395 ERROR:
Cluster lock called on freeing lockres T00000000000000000386019775b08d!
flags 0x81) is triggerred.

Call stack:

  (loop16,11155,0):ocfs2_lock_refcount_tree:482 ERROR: status = -5
  (loop16,11155,0):ocfs2_refcount_cow_hunk:3497 ERROR: status = -5
  (loop16,11155,0):ocfs2_refcount_cow:3560 ERROR: status = -5
  (loop16,11155,0):ocfs2_prepare_inode_for_refcount:2111 ERROR: status = -5
  (loop16,11155,0):ocfs2_prepare_inode_for_write:2190 ERROR: status = -5
  (loop16,11155,0):ocfs2_file_write_iter:2331 ERROR: status = -5
  (loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: bug expression:
  lockres->l_flags & OCFS2_LOCK_FREEING

  (loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: Cluster lock called on
  freeing lockres T00000000000000000386019775b08d! flags 0x81

  kernel BUG at fs/ocfs2/dlmglue.c:1395!

  invalid opcode: 0000 [#1] SMP  CPU 0
  Modules linked in: tun ocfs2 jbd2 xen_blkback xen_netback xen_gntdev .. sd_mod crc_t10dif ext3 jbd mbcache
  RIP: __ocfs2_cluster_lock+0x31c/0x740 [ocfs2]
  RSP: e02b:ffff88017c0138a0  EFLAGS: 00010086
  Process loop16 (pid: 11155, threadinfo ffff88017c010000, task ffff8801b5374300)
  Call Trace:
     ocfs2_refcount_lock+0xae/0x130 [ocfs2]
     __ocfs2_lock_refcount_tree+0x29/0xe0 [ocfs2]
     ocfs2_lock_refcount_tree+0xdd/0x320 [ocfs2]
     ocfs2_refcount_cow_hunk+0x1cb/0x440 [ocfs2]
     ocfs2_refcount_cow+0xa9/0x1d0 [ocfs2]
     ocfs2_prepare_inode_for_refcount+0x115/0x200 [ocfs2]
     ocfs2_prepare_inode_for_write+0x33b/0x470 [ocfs2]
     ocfs2_file_write_iter+0x220/0x8c0 [ocfs2]
     aio_write_iter+0x2e/0x30

Fix this by avoiding the second call to ocfs2_refcount_tree_put()

Link: http://lkml.kernel.org/r/1473984404-32011-1-git-send-email-ashish.samant@oracle.comSigned-off-by: NAshish Samant <ashish.samant@oracle.com>
Reviewed-by: NEric Ren <zren@suse.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Connect the new VFS clone_range, copy_range, and dedupe_range features
to the existing reflink capability of ocfs2.  Compared to the existing
ocfs2 reflink ioctl We have to do things a little differently to support
the VFS semantics (we can clone subranges of a file but we don't clone
xattrs), but the VFS ioctls are more broadly supported.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
---
v2: Convert inline data files to extents files before reflinking,
and fix i_blocks so that stat(2) output is correct.
v3: Make zero-length dedupe consistent with btrfs behavior.
v4: Use VFS double-inode lock routines and remove MAX_DEDUPE_LEN.

When ocfs2 shares blocks from one file to another, it's necessary to
charge that many blocks to the quota because ocfs2 tallies block charges
according to the number of blocks mapped, not the number of physical
blocks used.

Without this patch, reflinking X blocks and then CoWing all of them
causes quota usage to *decrease* by X as seen in generic/305.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

When we're adding the refcount flag to an extent, we have to budget
enough space to handle a full extent btree split in addition to
whatever modifications have to be made to the refcount btree.  We
don't currently do this, with the result that generic/186 crashes
when we need an extent split but not a refcount split because meta_ac
never gets allocated.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Replace the open-coded inode refcount flag test with a helper function
to reduce the potential for bugs.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NFelipe Balbi <balbi@kernel.org>
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
Acked-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit 702e5bc6 ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create.  The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs.  For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again.  This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted.  And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.

Fixes: 702e5bc6 ("ocfs2: use generic posix ACL infrastructure")
Signed-off-by: NTariq Saeed <tariq.x.saeed@oracle.com>
Signed-off-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mostly direct substitution with occasional adjustment or removing
outdated comments.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

readahead_pages in ocfs2_duplicate_clusters_by_page is defined but not
used, so clean it up.
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These uses sometimes do and sometimes don't have '\n' terminations.  Make
the uses consistently use '\n' terminations and remove the newline from
the functions.

Miscellanea:

o Coalesce formats
o Realign arguments
Signed-off-by: NJoe Perches <joe@perches.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Caveat: This may return -EROFS for a read case, which seems wrong.  This
is happening even without this patch series though.  Should we convert
EROFS to EIO?
Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dquot_initialize() can now return error. Handle it where possible.
Reviewed-by: NJunxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: NJan Kara <jack@suse.com>

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The code at the "out" label assumes that "default_acl" and "acl" are NULL,
but actually the pointers can be NULL, unitialized, or freed.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The assigned value is never used.

Coverity-id 1226847.
Signed-off-by: NJan Kara <jack@suse.cz>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ocfs2_search_extent_list may return -1, so we should check the return
value in ocfs2_split_and_insert, otherwise it may cause array index out of
bound.

And ocfs2_search_extent_list can only return value less than
el->l_next_free_rec, so check if it is equal or larger than
le16_to_cpu(el->l_next_free_rec) is meaningless.
Signed-off-by: NYingtai Xie <xieyingtai@huawei.com>
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch tries to fix this crash:

 #5 [ffff88003c1cd690] do_invalid_op at ffffffff810166d5
 #6 [ffff88003c1cd730] invalid_op at ffffffff8159b2de
    [exception RIP: ocfs2_direct_IO_get_blocks+359]
    RIP: ffffffffa05dfa27  RSP: ffff88003c1cd7e8  RFLAGS: 00010202
    RAX: 0000000000000000  RBX: ffff88003c1cdaa8  RCX: 0000000000000000
    RDX: 000000000000000c  RSI: ffff880027a95000  RDI: ffff88003c79b540
    RBP: ffff88003c1cd858   R8: 0000000000000000   R9: ffffffff815f6ba0
    R10: 00000000000001c9  R11: 00000000000001c9  R12: ffff88002d271500
    R13: 0000000000000001  R14: 0000000000000000  R15: 0000000000001000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffff88003c1cd860] do_direct_IO at ffffffff811cd31b
 #8 [ffff88003c1cd950] direct_IO_iovec at ffffffff811cde9c
 #9 [ffff88003c1cd9b0] do_blockdev_direct_IO at ffffffff811ce764
#10 [ffff88003c1cdb80] __blockdev_direct_IO at ffffffff811ce7cc
#11 [ffff88003c1cdbb0] ocfs2_direct_IO at ffffffffa05df756 [ocfs2]
#12 [ffff88003c1cdbe0] generic_file_direct_write_iter at ffffffff8112f935
#13 [ffff88003c1cdc40] ocfs2_file_write_iter at ffffffffa0600ccc [ocfs2]
#14 [ffff88003c1cdd50] do_aio_write at ffffffff8119126c
#15 [ffff88003c1cddc0] aio_rw_vect_retry at ffffffff811d9bb4
#16 [ffff88003c1cddf0] aio_run_iocb at ffffffff811db880
#17 [ffff88003c1cde30] io_submit_one at ffffffff811dc238
#18 [ffff88003c1cde80] do_io_submit at ffffffff811dc437
#19 [ffff88003c1cdf70] sys_io_submit at ffffffff811dc530
#20 [ffff88003c1cdf80] system_call_fastpath at ffffffff8159a159

It crashes at
        BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
in ocfs2_direct_IO_get_blocks.

ocfs2_direct_IO_get_blocks is expecting the OCFS2_EXT_REFCOUNTED be removed in
ocfs2_prepare_inode_for_write() if it was there. But no cluster lock is taken
during the time before (or inside) ocfs2_prepare_inode_for_write() and after
ocfs2_direct_IO_get_blocks().

It can happen in this case:

Node A(which crashes)				Node B
------------------------                 ---------------------------
ocfs2_file_aio_write
  ocfs2_prepare_inode_for_write
    ocfs2_inode_lock
    ...
    ocfs2_inode_unlock
  #no refcount found
....					ocfs2_reflink
                                          ocfs2_inode_lock
                                          ...
                                          ocfs2_inode_unlock
                                          #now, refcount flag set on extent

                                        ...
                                        flush change to disk

ocfs2_direct_IO_get_blocks
  ocfs2_get_clusters
    #extent map miss
    #buffer_head miss
    read extents from disk
  found refcount flag on extent
  crash..

Fix:
Take rw_lock in ocfs2_reflink path
Signed-off-by: NWengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are two standard techniques for dereferencing structures pointed
to by void *: cast to the right type each time they're used, or assign
to local variables of the right type.

But there's no need to do *both*.
Signed-off-by: NGeorge Spelvin <linux@horizon.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Reviewed-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This contains some major refactoring for the create path so that
inodes are created with the right mode to start with instead of
fixing it up later.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

sb_getblk() may return an err, so add a check for bh.

[joseph.qi@huawei.com: also add a check after calling sb_getblk() in ocfs2_create_xattr_block()]
Signed-off-by: NRui Xiang <rui.xiang@huawei.com>
Reviewed-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So return ENOMEM instead when it fails.

[joseph.qi@huawei.com: ocfs2_symlink_get_block() and ocfs2_read_blocks_sync() and ocfs2_read_blocks() need the same change]
Signed-off-by: NRui Xiang <rui.xiang@huawei.com>
Reviewed-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Code cleanup to remove unnecessary variable passed but never used
to ocfs2_calc_extend_credits.
Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In ocfs2_attach_refcount_tree() and ocfs2_duplicate_extent_list(), if
error occurs when calling ocfs2_get_clusters(), it will go with
unexpected behavior as local variables p_cluster, num_clusters and
ext_flags are declared without initialization.
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Reviewed-by: NJie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since ocfs2_cow_file_pos will invoke ocfs2_refcount_icow with a NULL as
the struct file pointer, it finally result in a null pointer dereference
in ocfs2_duplicate_clusters_by_page.

This patch replace file pointer with inode pointer in
cow_duplicate_clusters to fix this issue.

[jeff.liu@oracle.com: rebased patch against linux-next tree]
Signed-off-by: NTiger Yang <tiger.yang@oracle.com>
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: NTao Ma <tm@tao.ma>
Tested-by: NDavid Weber <wb@munzinger.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the missing NULL check of the return value of find_or_create_page() in
function ocfs2_duplicate_clusters_by_page().

[akpm@linux-foundation.org: fix layout, per Joel]
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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

Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

One side effect - attempt to create a cross-device link on a read-only fs fails
with EROFS instead of EXDEV now.  Makes more sense, POSIX allows, etc.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

releases what needs to be released after {kern,user}_path_create()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

le16, not le32...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

it's le16, not le32 or le64...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

It's le16, not le32...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

combination of kern_path_parent() and lookup_create().  Does *not*
expose struct nameidata to caller.  Syscalls converted to that...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The original goal of commonizing these funcs is to benefit defraging/extent_moving
codes in the future,  based on the fact that reflink and defragmentation having
the same Copy-On-Wrtie mechanism.
Signed-off-by: NTristan Ye <tristan.ye@oracle.com>

Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>