Commit Graph

307 Commits

Author SHA1 Message Date
Al Viro bd2843fe1f fix ufs write vs readpage race when writing into a hole
Followup to the UFS series - with the way we clear the new blocks (via
buffer cache, possibly on more than a page worth of file) we really
should not insert a reference to new block into inode block tree until
after we'd cleared it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09 10:43:12 -07:00
Al Viro 4e317ce73a ufs_inode_get{frag,block}(): get rid of 'phys' argument
Just pass NULL as locked_page in case of first block in the indirect
chain.  Old calling conventions aside, a reason for having 'phys'
was that ufs_inode_getfrag() used to be able to do _two_ allocations
- indirect block and extending/reallocating a tail.  We needed
locked_page for the latter (it's a data), but we also needed to
figure out that indirect block is metadata.  So we used to pass
non-NULL locked_page in all cases *and* used NULL phys as
indication of being asked to allocate an indirect.

With tail unpacking taken into a separate function we don't need
those convolutions anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:40:05 -04:00
Al Viro 0385f1f9e3 ufs_getfrag_block(): tidy up a bit
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:40:04 -04:00
Al Viro 5fbfb238f7 ufs_inode_getblock(): failure to read an indirect block is -EIO
... and not "write to beginning of the disk", TYVM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:40:03 -04:00
Al Viro 4eeff4c932 ufs_getfrag_block(): turn following indirects into a loop
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:40:02 -04:00
Al Viro 5336970be0 ufs_inode_getfrag(): pass index instead of 'fragment'
same story as with ufs_inode_getblock()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:40:01 -04:00
Al Viro 0f3c1294be ufs_inode_getfrag(): split extending the partial blocks off
ufs_extend_tail() is handling that now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:40:00 -04:00
Al Viro 619cfac091 ufs_inode_getblock(): pass indirect block number and full index
... instead of messing with buffer_head.  We can bloody well do
sb_bread() in there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:59 -04:00
Al Viro 721435a767 ufs_inode_getblock(): pass index instead of 'fragment'
The value passed to ufs_inode_getblock() as the 3rd argument
had lower bits ignored; the upper bits were shifted down
and used and they actually make sense - those are _lower_ bits
of index in indirect block (i.e. they form the index within
a fragment within an indirect block).

Pass those as argument.  Upper bits of index (i.e. the number
of fragment within indirect block) will join them shortly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:58 -04:00
Al Viro 177848a018 ufs_inode_get{frag,block}(): leave sb_getblk() to caller
just return the damn block number

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:57 -04:00
Al Viro 8d9dcf1436 ufs_getfrag_block(): get rid of macro jungles
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:56 -04:00
Al Viro bbb3eb9d34 ufs_inode_get{frag,block}(): consolidate success exits
These calling conventions are rudiments of pre-2.3 times; they
really need to be sanitized.  This is the first step; next
will be _always_ returning a block number, instead of this
"return a pointer to buffer_head, except when we get to the
actual data" crap.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:55 -04:00
Al Viro 71dd42846f ufs: use the branch depth in ufs_getfrag_block()
we'd already calculated it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:54 -04:00
Al Viro 4b7068c8b1 ufs: move calculation of offsets into ufs_getfrag_block()
... and massage ufs_frag_map() to take those instead of fragment number.

As it is, we duplicate the damn thing on the write side, open-coded and
bloody hard to follow.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:53 -04:00
Al Viro 5a39c25562 ufs_inode_get{frag,block}(): get rid of retries
We are holding ->truncate_mutex, so nobody else can alter our
block pointers.  Rechecks/retries were needed back when we
only held BKL there, and had to cope with write_begin/writepage
and writepage/truncate races.  Can't happen anymore...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:52 -04:00
Al Viro f53bd1421b __ufs_truncate_blocks(): avoid excessive dirtying of indirect blocks
There's a case when an indirect block gets dirtied for no good
reason - when there's a hole starting in the middle of area
covered by it and spanning past its end, and truncate() is done
precisely to the beginning of the hole.

The block is obviously not modified at all - all removals happen
beyond it.  However, existing code ends up dirtying it just in
case.  It's trivial to fix and while it's not a real bug by any
stretch of imagination, it makes the damn thing harder to follow.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:51 -04:00
Al Viro cc7231e309 free_full_branch(): don't bother modifying the block we are going to free
Note that it's already made unreachable from the inode, so we don't have
to worry about ufs_frag_map() walking into something already freed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:50 -04:00
Al Viro b6eede0ec6 move marking inode dirty to the end of __ufs_truncate_blocks()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:49 -04:00
Al Viro 163073db51 free_full_branch(): saner calling conventions
Have caller fetch the block number *and* remove it from wherever
it was.  Pass the block number instead.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:48 -04:00
Al Viro 7b4e4f7f81 ufs_trunc_branch(): kill recursion
turn recursion into a pair of loops

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:47 -04:00
Al Viro 6aab6dd379 ufs_trunc_branch(): massage towards killing recursion
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:46 -04:00
Al Viro 6d1ebbca2b split ufs_truncate_branch() into full- and partial-branch variants
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:45 -04:00
Al Viro a138b4b688 ufs: unify the logics for collecting adjacent data blocks to free
open-coded in several places...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:44 -04:00
Al Viro a96574233c ufs_trunc_branch(): separate the calls with non-NULL offsets
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:43 -04:00
Al Viro 97e0f8f87c ufs_trunc_branch(): never call with offsets != NULL && depth2 == 0
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:42 -04:00
Al Viro 42432739b5 __ufs_trunc_blocks(): turn the part after switch into a loop
... and turn the switch into if (), since all cases with
depth != 1 have just become identical.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:41 -04:00
Al Viro ef3a315d4c __ufs_truncate_blocks(): unify freeing the full branches
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:40 -04:00
Al Viro 9e0fbbde27 unify ufs_trunc_..indirect()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:39 -04:00
Al Viro 6775e24d9c ufs_trunc_..indirect(): more massage towards unifying
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:38 -04:00
Al Viro 85416288bf ufs_trunc_...indirect(): pass the array of indices instead of offsets
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:37 -04:00
Al Viro 7a4fdda724 __ufs_truncate(); find cutoff distances into branches by offsets[] array
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:36 -04:00
Al Viro 7bad5939fc ufs_trunc_dindirect(): pass the number of blocks to keep
same as the previous two.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:35 -04:00
Al Viro 6ac36b8777 ufs_trunc_indirect(): pass the index of the first pointer to free
... instead of file offset.  Same cleanups as in the tindirect
conversion in previous commit.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:34 -04:00
Al Viro 18ca51d821 ufs_trunc_tindirect(): pass the number of blocks to keep
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:33 -04:00
Al Viro 31cd043e1a ufs: beginning of __ufs_truncate_block() massage
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:32 -04:00
Al Viro 4e3911f3d7 ufs: the offsets ufs_block_to_path() puts into array are not sector_t
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:31 -04:00
Al Viro 010d331fc3 ufs: move truncate code into inode.c
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:30 -04:00
Al Viro 0d23cf7616 ufs: no retries are needed on truncate
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:29 -04:00
Al Viro 687857930d ufs: ufs_trunc_...() has exclusion with everything that might cause allocations
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:28 -04:00
Al Viro 6a799d3514 ufs: ufs_trunc_direct() always returns 0
make it return void

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:27 -04:00
Al Viro dff7cfd36e ufs: kill lock_ufs()
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:26 -04:00
Al Viro 724bb09fdc ufs: don't use lock_ufs() for block pointers tree protection
* 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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:25 -04:00
Al Viro 4af7b2c080 ufs: bforget() indirect blocks before freeing them
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:24 -04:00
Al Viro 493b4537a2 ufs: move lock_ufs() down into __ufs_truncate_blocks()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:23 -04:00
Al Viro 2401aa29ab ufs: move truncate_setsize() down into ufs_truncate()
just prior to __ufs_truncate_blocks(), with matching change of calling
conventions

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:22 -04:00
Al Viro 3b7a3a05e8 ufs: free excessive blocks upon ->write_begin() failure/short copy
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:21 -04:00
Al Viro d622f167b8 ufs: switch ufs_evict_inode() to trimmed-down variant of ufs_truncate()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:20 -04:00
Al Viro f3e0f3da1b ufs: kill more lock_ufs() calls
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: Al Viro <viro@zeniv.linux.org.uk>
2015-07-06 17:39:19 -04:00
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds e4bc13adfd Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block
Pull cgroup writeback support from Jens Axboe:
 "This is the big pull request for adding cgroup writeback support.

  This code has been in development for a long time, and it has been
  simmering in for-next for a good chunk of this cycle too.  This is one
  of those problems that has been talked about for at least half a
  decade, finally there's a solution and code to go with it.

  Also see last weeks writeup on LWN:

        http://lwn.net/Articles/648292/"

* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
  writeback, blkio: add documentation for cgroup writeback support
  vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
  writeback: do foreign inode detection iff cgroup writeback is enabled
  v9fs: fix error handling in v9fs_session_init()
  bdi: fix wrong error return value in cgwb_create()
  buffer: remove unusued 'ret' variable
  writeback: disassociate inodes from dying bdi_writebacks
  writeback: implement foreign cgroup inode bdi_writeback switching
  writeback: add lockdep annotation to inode_to_wb()
  writeback: use unlocked_inode_to_wb transaction in inode_congested()
  writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
  writeback: implement [locked_]inode_to_wb_and_lock_list()
  writeback: implement foreign cgroup inode detection
  writeback: make writeback_control track the inode being written back
  writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
  mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
  writeback: implement memcg writeback domain based throttling
  writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
  writeback: implement memcg wb_domain
  writeback: update wb_over_bg_thresh() to use wb_domain aware operations
  ...
2015-06-25 16:00:17 -07:00