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

Have caller fetch the block number *and* remove it from wherever
it was.  Pass the block number instead.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

turn recursion into a pair of loops
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We always have 0 < depth2 <= depth in there, so
if (--depth) {
	if (--depth2)
		A
	B
} else {
	C // not using depth2
}
D // not using depth2

is equivalent to

if (--depth2)
	A with s/depth/depth - 1/
if (--depth)
	B
else
	C
D
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

open-coded in several places...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

For calls in __ufs_truncate_blocks() it's just a matter of not
incrementing offsets[0] and not making that call - immediately
following loop will be executed one extra time and we'll be just
fine.  For recursive call in ufs_trunc_branch() itself, just
assing NULL to offsets if we would be about to make such call.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and turn the switch into if (), since all cases with
depth != 1 have just become identical.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

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

Instead of manually checking that the array contains only zeroes,
find the position of the last non-zero (in __ufs_truncate(), where
we can conveniently do that) and use that to tell if there's
any non-zero in the array tail passed to ufs_trunc_...indirect().

The goal of all that clumsiness is to get fold these functions
together.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

rather than bitslicing the offset just formed as sum of shifted indices,
pass the array of those indices itself.  NULL is used as equivalent
of "all zeroes" (== free the entire branch).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

same as the previous two.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... instead of file offset.  Same cleanups as in the tindirect
conversion in previous commit.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

IOW, the distance of cutoff from the begining of the branch
(in blocks).

That (and the fact that block just prior to cutoff is guaranteed to
be present) allows to tell whether to free triple indirect block
just by looking at the offset.

While we are at it, using u64 for index in the block is wrong -
those should be unsigned int.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use ufs_block_to_path() to find the cutoff path in the block pointers' tree.
For now just use the information about the depth (to bypass the fully
preserved subtrees); subsequent commits will use the information about actual
path.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

type makes no sense - those are indices in block number arrays, not
block numbers.  And no, UFS is not likely to grow indirect blocks with
4Gpointers in them...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

It is closely tied to block pointers handling there, can benefit
from existing helpers, etc. - no point keeping them apart.

Trimmed the trailing whitespaces in inode.c at the same time.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

	Currently - on lock_ufs(), eventually - on per-inode mutex.
lock_ufs() used to be mere BKL, which is much weaker, so it needed
those rechecks.  BKL doesn't provide any exclusion once we lose CPU;
its blind replacement, OTOH, _does_.  Making that per-filesystem was
an atrocity, but at least we can simplify life here.  And yes, we
certainly need to make that sucker per-inode - these days inode.c and
truncate.c uses are needed only to protect the block pointers.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

There were 3 remaining users; in two of them we took ->s_lock immediately
after lock_ufs() and held it until just before unlock_ufs(); the third
one (statfs) could not be called from itself or from other two (remount
and sync_fs).  Just use ->s_lock in statfs and don't bother with lock_ufs
at all.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* stores to block pointers are under per-inode seqlock (meta_lock) and
mutex (truncate_mutex)
* fetches of block pointers are either under truncate_mutex, or wrapped
into seqretry loop on meta_lock
* all changes of ->i_size are under truncate_mutex and i_mutex
* all changes of ->i_lastfrag are under truncate_mutex

It's similar to what ext2 is doing; the main difference is that unlike
ext2 we can't rely upon the atomicity of stores into block pointers -
on UFS2 they are 64bit.  So we can't cut the corner when switching
a pointer from NULL to non-NULL as we could in ext2_splice_branch()
and need to use meta_lock on all modifications.

We use seqlock where ext2 uses rwlock; ext2 could probably also benefit
from such change...

Another non-trivial difference is that with UFS we *cannot* have reader
grab truncate_mutex in case of race - it has to keep retrying.  That
might be possible to change, but not until we lift tail unpacking
several levels up in call chain.

After that commit we do *NOT* hold fs-wide serialization on accesses
to block pointers anymore.  Moreover, lock_ufs() can become a normal
mutex now - it's only used on statfs, remount and sync_fs and none
of those uses are recursive.  As the matter of fact, *now* it can be
collapsed with ->s_lock, and be eventually replaced with saner
per-cylinder-group spinlocks, but that's a separate story.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

right now it doesn't matter (lock_ufs() serializes everything),
but when we switch to per-inode locking, it will be needed.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

just prior to __ufs_truncate_blocks(), with matching change of calling
conventions
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Broken in "[PATCH] ufs: truncate should allocate block for last byte";
all way back in 2006.  ufs_setattr() hadn't been the only user of
vmtruncate() and eliminating ->truncate() method required corrections
in a bunch of places.  Eventually those places had migrated into
->write_begin() failure exit and ->write_end() after short copy...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

a) move it inside ufs_truncate()
b) ufs_free_inode() doesn't need it - it's serialized on ->s_lock
c) ufs_write_inode() doesn't need it either (and can be called without
it anyway).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

dir_pages was declared in a lot of filesystems.
Use newly dir_pages() from pagemap.h
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add last missing line in commit "cdd9eefd"
("fs/ufs: restore s_lock mutex")
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

See "ext2: Do not update mtime of a moved directory" (and followup in
"ext2: fix unbalanced kmap()/kunmap()") for background; this is UFS
equivalent - the same problem exists here.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We are already serialized by ->i_mutex and operations on different
directories are independent.  These calls are just rudiments of
blind BKL conversion and they should've been removed back then.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit e4502c63 (ufs: deal with nfsd/iget races) made ufs
create inodes with I_NEW flag set. However ufs_mkdir() never cleared
this flag. Thus if someone ever tried to lookup the directory by inode
number, he would deadlock waiting for I_NEW to be cleared. Luckily this
mostly happens only if the filesystem is exported over NFS since
otherwise we have the inode attached to dentry and don't look it up by
inode number. In rare cases dentry can get freed without inode being
freed and then we'd hit the deadlock even without NFS export.

Fix the problem by clearing I_NEW before instantiating new directory
inode.

Fixes: e4502c63Reported-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit e4502c63 (ufs: deal with nfsd/iget races) introduced
unlock_new_inode() call into ufs_add_nondir(). However that function
gets called also from ufs_link() which hands it already initialized
inode and thus unlock_new_inode() complains. The problem is harmless but
annoying.

Fix the problem by opencoding necessary stuff in ufs_link()

Fixes: e4502c63Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit 0244756e ("ufs: sb mutex merge + mutex_destroy") generated
deadlocks in read/write mode on mkdir.

This patch partially reverts it keeping fixes by Andrew Morton and
mutex_destroy()

[AV: fixed a missing bit in ufs_remount()]
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Reported-by: NIan Campbell <ian.campbell@citrix.com>
Suggested-by: NJan Kara <jack@suse.cz>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Roger Pau Monne <roger.pau@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This reverts commit 9ef7db7f ("ufs: fix deadlocks introduced by sb
mutex merge") That patch tried to solve commit 0244756e ("ufs: sb
mutex merge + mutex_destroy") which is itself partially reverted due to
multiple deadlocks.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Suggested-by: NJan Kara <jack@suse.cz>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Roger Pau Monne <roger.pau@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it.  c files
which need access to more backing-dev details now include
backing-dev.h directly.  This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NJens Axboe <axboe@fb.com>