Commit Graph

47524 Commits

Author SHA1 Message Date
Benjamin Coddington
149a4fddd0 nfs: don't create zero-length requests
NFS doesn't expect requests with wb_bytes set to zero and may make
unexpected decisions about how to handle that request at the page IO layer.
Skip request creation if we won't have any wb_bytes in the request.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Weston Andros Adamson <dros@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-07-22 15:15:16 -04:00
Artem Savkov
297fae4d0b Fix NULL pointer dereference in bl_free_device().
When bl_parse_deviceid() fails in bl_alloc_deviceid_node() on
blkdev_get_by_*() step we get an pnfs_block_dev struct that is
uninitialized except for bdev field which is set to whatever error
blkdev_get_by_*() returns.  bl_free_device() then tries to call
blkdev_put() if bdev is not 0 resulting in a wrong pointer dereference.

Fixing this by setting bdev in struct pnfs_block_dev only if we didn't
get an error from blkdev_get_by_*().

Signed-off-by: Artem Savkov <asavkov@redhat.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-07-22 15:14:21 -04:00
Yunlei He
fe94793e55 f2fs: get victim segment again after new cp
Previous selected segment may become free after write_checkpoint,
if we do garbage collect on this segment, and then new_curseg happen
to reuse it, it may cause f2fs_bug_on as below.

	panic+0x154/0x29c
	do_garbage_collect+0x15c/0xaf4
	f2fs_gc+0x2dc/0x444
	f2fs_balance_fs.part.22+0xcc/0x14c
	f2fs_balance_fs+0x28/0x34
	f2fs_map_blocks+0x5ec/0x790
	f2fs_preallocate_blocks+0xe0/0x100
	f2fs_file_write_iter+0x64/0x11c
	new_sync_write+0xac/0x11c
	vfs_write+0x144/0x1e4
	SyS_write+0x60/0xc0

Here, maybe we check sit and ssa type during reset_curseg. So, we check
segment is stale or not, and select a new victim to avoid this.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-22 11:55:31 -07:00
Maxim Patlasov
cfc9fde0b0 ovl: verify upper dentry in ovl_remove_and_whiteout()
The upper dentry may become stale before we call ovl_lock_rename_workdir.
For example, someone could (mistakenly or maliciously) manually unlink(2)
it directly from upperdir.

To ensure it is not stale, let's lookup it after ovl_lock_rename_workdir
and and check if it matches the upper dentry.

Essentially, it is the same problem and similar solution as in
commit 11f3710417 ("ovl: verify upper dentry before unlink and rename").

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
2016-07-22 10:54:20 +02:00
Dave Chinner
f2bdfda9a1 Merge branch 'xfs-4.8-misc-fixes-4' into for-next 2016-07-22 14:10:56 +10:00
Dave Chinner
72ccbbe154 xfs: remove EXPERIMENTAL tag from sparse inode feature
Been around for long enough now, hasn't caused any regression test
failures in the past 3 months, so it's time to make it a fully
supported feature.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-22 14:10:18 +10:00
Dave Chinner
28b783e47a xfs: bufferhead chains are invalid after end_page_writeback
In xfs_finish_page_writeback(), we have a loop that looks like this:

        do {
                if (off < bvec->bv_offset)
                        goto next_bh;
                if (off > end)
                        break;
                bh->b_end_io(bh, !error);
next_bh:
                off += bh->b_size;
        } while ((bh = bh->b_this_page) != head);

The b_end_io function is end_buffer_async_write(), which will call
end_page_writeback() once all the buffers have marked as no longer
under IO.  This issue here is that the only thing currently
protecting both the bufferhead chain and the page from being
reclaimed is the PageWriteback state held on the page.

While we attempt to limit the loop to just the buffers covered by
the IO, we still read from the buffer size and follow the next
pointer in the bufferhead chain. There is no guarantee that either
of these are valid after the PageWriteback flag has been cleared.
Hence, loops like this are completely unsafe, and result in
use-after-free issues. One such problem was caught by Calvin Owens
with KASAN:

.....
 INFO: Freed in 0x103fc80ec age=18446651500051355200 cpu=2165122683 pid=-1
  free_buffer_head+0x41/0x90
  __slab_free+0x1ed/0x340
  kmem_cache_free+0x270/0x300
  free_buffer_head+0x41/0x90
  try_to_free_buffers+0x171/0x240
  xfs_vm_releasepage+0xcb/0x3b0
  try_to_release_page+0x106/0x190
  shrink_page_list+0x118e/0x1a10
  shrink_inactive_list+0x42c/0xdf0
  shrink_zone_memcg+0xa09/0xfa0
  shrink_zone+0x2c3/0xbc0
.....
 Call Trace:
  <IRQ>  [<ffffffff81e8b8e4>] dump_stack+0x68/0x94
  [<ffffffff8153a995>] print_trailer+0x115/0x1a0
  [<ffffffff81541174>] object_err+0x34/0x40
  [<ffffffff815436e7>] kasan_report_error+0x217/0x530
  [<ffffffff81543b33>] __asan_report_load8_noabort+0x43/0x50
  [<ffffffff819d651f>] xfs_destroy_ioend+0x3bf/0x4c0
  [<ffffffff819d69d4>] xfs_end_bio+0x154/0x220
  [<ffffffff81de0c58>] bio_endio+0x158/0x1b0
  [<ffffffff81dff61b>] blk_update_request+0x18b/0xb80
  [<ffffffff821baf57>] scsi_end_request+0x97/0x5a0
  [<ffffffff821c5558>] scsi_io_completion+0x438/0x1690
  [<ffffffff821a8d95>] scsi_finish_command+0x375/0x4e0
  [<ffffffff821c3940>] scsi_softirq_done+0x280/0x340


Where the access is occuring during IO completion after the buffer
had been freed from direct memory reclaim.

Prevent use-after-free accidents in this end_io processing loop by
pre-calculating the loop conditionals before calling bh->b_end_io().
The loop is already limited to just the bufferheads covered by the
IO in progress, so the offset checks are sufficient to prevent
accessing buffers in the chain after end_page_writeback() has been
called by the the bh->b_end_io() callout.

Yet another example of why Bufferheads Must Die.

cc: <stable@vger.kernel.org> # 4.7
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reported-and-Tested-by: Calvin Owens <calvinowens@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-22 09:56:38 +10:00
Dave Chinner
b1c5ebb213 xfs: allocate log vector buffers outside CIL context lock
One of the problems we currently have with delayed logging is that
under serious memory pressure we can deadlock memory reclaim. THis
occurs when memory reclaim (such as run by kswapd) is reclaiming XFS
inodes and issues a log force to unpin inodes that are dirty in the
CIL.

The CIL is pushed, but this will only occur once it gets the CIL
context lock to ensure that all committing transactions are complete
and no new transactions start being committed to the CIL while the
push switches to a new context.

The deadlock occurs when the CIL context lock is held by a
committing process that is doing memory allocation for log vector
buffers, and that allocation is then blocked on memory reclaim
making progress. Memory reclaim, however, is blocked waiting for
a log force to make progress, and so we effectively deadlock at this
point.

To solve this problem, we have to move the CIL log vector buffer
allocation outside of the context lock so that memory reclaim can
always make progress when it needs to force the log. The problem
with doing this is that a CIL push can take place while we are
determining if we need to allocate a new log vector buffer for
an item and hence the current log vector may go away without
warning. That means we canot rely on the existing log vector being
present when we finally grab the context lock and so we must have a
replacement buffer ready to go at all times.

To ensure this, introduce a "shadow log vector" buffer that is
always guaranteed to be present when we gain the CIL context lock
and format the item. This shadow buffer may or may not be used
during the formatting, but if the log item does not have an existing
log vector buffer or that buffer is too small for the new
modifications, we swap it for the new shadow buffer and format
the modifications into that new log vector buffer.

The result of this is that for any object we modify more than once
in a given CIL checkpoint, we double the memory required
to track dirty regions in the log. For single modifications then
we consume the shadow log vectorwe allocate on commit, and that gets
consumed by the checkpoint. However, if we make multiple
modifications, then the second transaction commit will allocate a
shadow log vector and hence we will end up with double the memory
usage as only one of the log vectors is consumed by the CIL
checkpoint. The remaining shadow vector will be freed when th elog
item is freed.

This can probably be optimised in future - access to the shadow log
vector is serialised by the object lock (as opposited to the active
log vector, which is controlled by the CIL context lock) and so we
can probably free shadow log vector from some objects when the log
item is marked clean on removal from the AIL.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-22 09:52:35 +10:00
Dave Chinner
160ae76fa1 libxfs: directory node splitting does not have an extra block
xfsprogs source commit 4280e59dcbc4cd8e01585efe788a68eb378048e8

xfs_da3_split() has to handle all three versions of the
directory/attribute btree structure. The attr tree is v1, the dir
tre is v2 or v3. The main difference between the v1 and v2/3 trees
is the way tree nodes are split - in the v1 tree we can require a
double split to occur because the object to be inserted may be
larger than the space made by splitting a leaf. In this case we need
to do a double split - one to split the full leaf, then another to
allocate an empty leaf block in the correct location for the new
entry.  This does not happen with dir (v2/v3) formats as the objects
being inserted are always guaranteed to fit into the new space in
the split blocks.

Indeed, for directories they *may* be an extra block on this buffer
pointer. However, it's guaranteed not to be a leaf block (i.e. a
directory data block) - the directory code only ever places hash
index or free space blocks in this pointer (as a cursor of
sorts), and so to use it as a directory data block will immediately
corrupt the directory.

The problem is that the code assumes that there may be extra blocks
that we need to link into the tree once we've split the root, but
this is not true for either dir or attr trees, because the extra
attr block is always consumed by the last node split before we split
the root. Hence the linking in an extra block is always wrong at the
root split level, and this manifests itself in repair as a directory
corruption in a repaired directory, leaving the directory rebuild
incomplete.

This is a dir v2 zero-day bug - it was in the initial dir v2 commit
that was made back in February 1998.

Fix this by ensuring the linking of the blocks after the root split
never tries to make use of the extra blocks that may be held in the
cursor. They are held there for other purposes and should never be
touched by the root splitting code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-22 09:51:05 +10:00
Arnd Bergmann
f021bd071f xfs: remove dax code from object file when disabled
We check IS_DAX(inode) before calling either xfs_file_dax_read or
xfs_file_dax_write, and this will lead the call being optimized out at
compile time when CONFIG_FS_DAX is disabled.

However, the two functions are marked STATIC, so they become global
symbols when CONFIG_XFS_DEBUG is set, leaving us with two unused global
functions that call into an undefined function and a broken "allmodconfig"
build:

fs/built-in.o: In function `xfs_file_dax_read':
fs/xfs/xfs_file.c:348: undefined reference to `dax_do_io'
fs/built-in.o: In function `xfs_file_dax_write':
fs/xfs/xfs_file.c:758: undefined reference to `dax_do_io'

Marking the two functions 'static noinline' instead of 'STATIC' will let
the compiler drop the symbols when there are no callers but avoid the
implicit inlining.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 16d4d43595 ("xfs: split direct I/O and DAX path")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-22 09:50:55 +10:00
Brian Foster
99579ccec4 xfs: skip dirty pages in ->releasepage()
XFS has had scattered reports of delalloc blocks present at
->releasepage() time. This results in a warning with a stack trace
similar to the following:

 ...
 Call Trace:
  [<ffffffffa23c5b8f>] dump_stack+0x63/0x84
  [<ffffffffa20837a7>] warn_slowpath_common+0x97/0xe0
  [<ffffffffa208380a>] warn_slowpath_null+0x1a/0x20
  [<ffffffffa2326caf>] xfs_vm_releasepage+0x10f/0x140
  [<ffffffffa218c680>] ? page_mkclean_one+0xd0/0xd0
  [<ffffffffa218d3a0>] ? anon_vma_prepare+0x150/0x150
  [<ffffffffa21521c2>] try_to_release_page+0x32/0x50
  [<ffffffffa2166b2e>] shrink_active_list+0x3ce/0x3e0
  [<ffffffffa21671c7>] shrink_lruvec+0x687/0x7d0
  [<ffffffffa21673ec>] shrink_zone+0xdc/0x2c0
  [<ffffffffa2168539>] kswapd+0x4f9/0x970
  [<ffffffffa2168040>] ? mem_cgroup_shrink_node_zone+0x1a0/0x1a0
  [<ffffffffa20a0d99>] kthread+0xc9/0xe0
  [<ffffffffa20a0cd0>] ? kthread_stop+0x100/0x100
  [<ffffffffa26b404f>] ret_from_fork+0x3f/0x70
  [<ffffffffa20a0cd0>] ? kthread_stop+0x100/0x100

This occurs because it is possible for shrink_active_list() to send
pages marked dirty to ->releasepage() when certain buffer_head threshold
conditions are met. shrink_active_list() doesn't check the page dirty
state apparently to handle an old ext3 corner case where in some cases
clean pages would not have the dirty bit cleared, thus it is up to the
filesystem to determine how to handle the page.

XFS currently handles the delalloc case properly, but this behavior
makes the warning spurious. Update the XFS ->releasepage() handler to
explicitly skip dirty pages. Retain the existing delalloc/unwritten
checks so we continue to warn if such buffers exist on clean pages when
they shouldn't.

Diagnosed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-22 09:50:38 +10:00
Bob Peterson
e1cb6be9e1 GFS2: Fix gfs2_replay_incr_blk for multiple journal sizes
Before this patch, if you used gfs2_jadd to add new journals of a
size smaller than the existing journals, replaying those new journals
would withdraw. That's because function gfs2_replay_incr_blk was
using the number of journal blocks (jd_block) from the superblock's
journal pointer. In other words, "My journal's max size" rather than
"the journal we're replaying's size." This patch changes the function
to use the size of the pertinent journal rather than always using the
journal we happen to be using.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2016-07-21 13:02:44 -05:00
Trond Myklebust
e033fb51eb pNFS/files: filelayout_write_done_cb must call nfs_writeback_update_inode()
All write callbacks are required to call nfs_writeback_update_inode() upon
success to ensure that file size changes are recorded, and the attribute
cache is invalidated.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-07-21 09:46:42 -04:00
Chris Mason
8b8b08cbfb Btrfs: fix delalloc accounting after copy_from_user faults
Commit 56244ef151 was almost but not quite enough to fix the
reservation math after btrfs_copy_from_user returned partial copies.

Some users are still seeing warnings in btrfs_destroy_inode, and with a
long enough test run I'm able to trigger them as well.

This patch fixes the accounting math again, bringing it much closer to
the way it was before the sectorsize conversion Chandan did.  The
problem is accounting for the offset into the page/sector when we do a
partial copy.  This one just uses the dirty_sectors variable which
should already be updated properly.

Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org # v4.6+
2016-07-21 04:03:40 -07:00
Miklos Szeredi
0f7d93416d Merge branch 'for-miklos' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into for-next 2016-07-21 11:14:30 +02:00
Al Viro
9aba36dea5 qstr constify instances in fs/dcache.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Al Viro
beffb8feb6 qstr: constify instances in nfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Al Viro
612645f7cf qstr: constify instances in ocfs2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Al Viro
8ac790f312 qstr: constify instances in autofs4
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Al Viro
71e939634d qstr: constify instances in hfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Al Viro
b5cce521e8 qstr: constify instances in hfsplus
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Al Viro
7f5458ec5c qstr: constify instances in logfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Toshi Kani
163d4baaeb block: add QUEUE_FLAG_DAX for devices to advertise their DAX support
Currently, presence of direct_access() in block_device_operations
indicates support of DAX on its block device.  Because
block_device_operations is instantiated with 'const', this DAX
capablity may not be enabled conditinally.

In preparation for supporting DAX to device-mapper devices, add
QUEUE_FLAG_DAX to request_queue flags to advertise their DAX
support.  This will allow to set the DAX capability based on how
mapped device is composed.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <linux-s390@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20 21:01:01 -06:00
Josef Bacik
bac357dcec Btrfs: avoid deadlocks during reservations in btrfs_truncate_block
The new enospc code makes it possible to deadlock if we don't use
FLUSH_LIMIT during reservations inside a transaction.  This enforces
the correct flush type to avoid both deadlocks and assertions

Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
2016-07-20 16:58:04 -07:00
Christoph Hellwig
70246286e9 block: get rid of bio_rw and READA
These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces.  For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense.  Any check for READA is replaced with an
explicit check for REQ_RAHEAD.  Also remove the READA alias for
REQ_RAHEAD.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20 17:37:01 -06:00
Jaegeuk Kim
6f3ec9952c f2fs: handle error case with f2fs_bug_on
It's enough to show BUG or WARN by f2fs_bug_on for error case.
Then, we don't need to remain corrupted filesystem.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-20 14:53:22 -07:00
Jaegeuk Kim
dd11a5df52 f2fs: avoid data race when deciding checkpoin in f2fs_sync_file
When fs utilization is almost full, f2fs_sync_file should do checkpoint if
there is not enough space for roll-forward later. (i.e. space_for_roll_forward)
So, currently we have no lock for sbi->alloc_valid_block_count, resulting in
race condition.

In rare case, we can get -ENOSPC when doing roll-forward which triggers

	if (is_valid_blkaddr(sbi, dest, META_POR)) {
		if (src == NULL_ADDR) {
			err = reserve_new_block(&dn);
			f2fs_bug_on(sbi, err);
			...
		}
		...
	}
in do_recover_data.

So, this patch avoids that situation in advance.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-20 14:53:21 -07:00
Jaegeuk Kim
4dd6f977fc f2fs: support an ioctl to move a range of data blocks
This patch implements moving a range of data blocks from source file to
destination file.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-20 14:53:20 -07:00
Chao Yu
91246c21b8 f2fs: fix to report error number of f2fs_find_entry
This patch fixes to report the right error number of f2fs_find_entry to
its caller.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-20 14:53:19 -07:00
Rabin Vincent
bd975d1eea cifs: fix crash due to race in hmac(md5) handling
The secmech hmac(md5) structures are present in the TCP_Server_Info
struct and can be shared among multiple CIFS sessions.  However, the
server mutex is not currently held when these structures are allocated
and used, which can lead to a kernel crashes, as in the scenario below:

mount.cifs(8) #1				mount.cifs(8) #2

Is secmech.sdeschmaccmd5 allocated?
// false

						Is secmech.sdeschmaccmd5 allocated?
						// false

secmech.hmacmd = crypto_alloc_shash..
secmech.sdeschmaccmd5 = kzalloc..
sdeschmaccmd5->shash.tfm = &secmec.hmacmd;

						secmech.sdeschmaccmd5 = kzalloc
						// sdeschmaccmd5->shash.tfm
						// not yet assigned

crypto_shash_update()
 deref NULL sdeschmaccmd5->shash.tfm

 Unable to handle kernel paging request at virtual address 00000030
 epc   : 8027ba34 crypto_shash_update+0x38/0x158
 ra    : 8020f2e8 setup_ntlmv2_rsp+0x4bc/0xa84
 Call Trace:
  crypto_shash_update+0x38/0x158
  setup_ntlmv2_rsp+0x4bc/0xa84
  build_ntlmssp_auth_blob+0xbc/0x34c
  sess_auth_rawntlmssp_authenticate+0xac/0x248
  CIFS_SessSetup+0xf0/0x178
  cifs_setup_session+0x4c/0x84
  cifs_get_smb_ses+0x2c8/0x314
  cifs_mount+0x38c/0x76c
  cifs_do_mount+0x98/0x440
  mount_fs+0x20/0xc0
  vfs_kern_mount+0x58/0x138
  do_mount+0x1e8/0xccc
  SyS_mount+0x88/0xd4
  syscall_common+0x30/0x54

Fix this by locking the srv_mutex around the code which uses these
hmac(md5) structures.  All the other secmech algos already have similar
locking.

Fixes: 95dc8dd14e ("Limit allocation of crypto mechanisms to dialect which requires")
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2016-07-20 03:03:27 -05:00
Dave Chinner
dc4113d243 Merge branch 'xfs-4.8-dir2-sf-fixes' into for-next 2016-07-20 11:54:59 +10:00
Dave Chinner
b47ec80bfe Merge branch 'xfs-4.8-split-dax-dio' into for-next 2016-07-20 11:54:37 +10:00
Dave Chinner
bbfeb6141f Merge branch 'xfs-4.8-buf-fixes' into for-next 2016-07-20 11:53:35 +10:00
Dave Chinner
f63716175c Merge branch 'xfs-4.8-misc-fixes-3' into for-next 2016-07-20 11:51:08 +10:00
Christoph Hellwig
aa2dd0ad4d xfs: remove __arch_pack
Instead we always declare struct xfs_dir2_sf_hdr as packed.  That's
the expected layout, and while most major architectures do the packing
by default the new structure size and offset checker showed that not
only the ARM old ABI got this wrong, but various minor embedded
architectures did as well.

[Verified that no code change on x86-64 results from this change]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:48:46 +10:00
Christoph Hellwig
266b6969c3 xfs: kill xfs_dir2_inou_t
And use an array of unsigned char values directly to avoid problems
with architectures that pad the size of structures.  This also gets
rid of the xfs_dir2_ino4_t and xfs_dir2_ino8_t types, and introduces
new constants for the size of 4 and 8 bytes as well as the size
difference between the two.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:48:31 +10:00
Christoph Hellwig
8353a649f5 xfs: kill xfs_dir2_sf_off_t
Just use an array of two unsigned chars directly to avoid problems
with architectures that pad the size of structures.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:47:21 +10:00
Christoph Hellwig
16d4d43595 xfs: split direct I/O and DAX path
So far the DAX code overloaded the direct I/O code path.  There is very little
in common between the two, and untangling them allows to clean up both variants.

As a side effect we also get separate trace points for both I/O types.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:38:55 +10:00
Christoph Hellwig
fa8d972d05 xfs: direct calls in the direct I/O path
We control both the callers and callees of ->direct_IO, so remove the
indirect calls.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:38:01 +10:00
Christoph Hellwig
f1285ff0ac xfs: stop using generic_file_read_iter for direct I/O
XFS already implement it's own flushing of the pagecache because it
implements proper synchronization for direct I/O reads.  This means
calling generic_file_read_iter for direct I/O is rather useless,
as it doesn't do much but updating the atime and iocb position for
us.  This also gets rid of the buffered I/O fallback that isn't used
for XFS.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:36:57 +10:00
Christoph Hellwig
bbc5a740c4 xfs: split xfs_file_read_iter into buffered and direct I/O helpers
Similar to what we did on the write side a while ago.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:35:42 +10:00
Christoph Hellwig
cf810712cc xfs: remove s_maxbytes enforcement in xfs_file_read_iter
All the three low-level read implementations that we might call already
take care of not overflowing the maximum supported bytes, no need to
duplicate it here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:31:53 +10:00
Christoph Hellwig
3176c3e0ef xfs: kill ioflags
Now that we have the direct I/O kiocb flag there is no real need to sample
the value inside of XFS, and the invis flag was always just partially used
and isn't worth keeping this infrastructure around for.   This also splits
the read tracepoint into buffered vs direct as we've done for writes a long
time ago.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:31:42 +10:00
Christoph Hellwig
8f3e2058e1 xfs: don't pass ioflags around in the ioctl path
Instead check the file pointer for the invisble I/O flag directly, and
use the chance to drop redundant arguments from the xfs_ioc_space
prototype.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:29:35 +10:00
Brian Foster
9c7504aa72 xfs: track and serialize in-flight async buffers against unmount
Newly allocated XFS metadata buffers are added to the LRU once the hold
count is released, which typically occurs after I/O completion. There is
no other mechanism at current that tracks the existence or I/O state of
a new buffer. Further, readahead I/O tends to be submitted
asynchronously by nature, which means the I/O can remain in flight and
actually complete long after the calling context is gone. This means
that file descriptors or any other holds on the filesystem can be
released, allowing the filesystem to be unmounted while I/O is still in
flight. When I/O completion occurs, core data structures may have been
freed, causing completion to run into invalid memory accesses and likely
to panic.

This problem is reproduced on XFS via directory readahead. A filesystem
is mounted, a directory is opened/closed and the filesystem immediately
unmounted. The open/close cycle triggers a directory readahead that if
delayed long enough, runs buffer I/O completion after the unmount has
completed.

To address this problem, add a mechanism to track all in-flight,
asynchronous buffers using per-cpu counters in the buftarg. The buffer
is accounted on the first I/O submission after the current reference is
acquired and unaccounted once the buffer is returned to the LRU or
freed. Update xfs_wait_buftarg() to wait on all in-flight I/O before
walking the LRU list. Once in-flight I/O has completed and the workqueue
has drained, all new buffers should have been released onto the LRU.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:15:28 +10:00
Brian Foster
c891c30a4d xfs: exclude never-released buffers from buftarg I/O accounting
The upcoming buftarg I/O accounting mechanism maintains a count of
all buffers that have undergone I/O in the current hold-release
cycle.  Certain buffers associated with core infrastructure (e.g.,
the xfs_mount superblock buffer, log buffers) are never released,
however. This means that accounting I/O submission on such buffers
elevates the buftarg count indefinitely and could lead to lockup on
unmount.

Define a new buffer flag to explicitly exclude buffers from buftarg
I/O accounting. Set the flag on the superblock and associated log
buffers.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:13:43 +10:00
Eric Sandeen
5539d36752 xfs: don't reset b_retries to 0 on every failure
With the code as it stands today, b_retries never increments because
it gets reset to 0 in the error callback.

Remove that, and fix a similar problem where the first retry time
was constantly being overwritten, which defeated the timeout tunable
as well.  We now only set first retry time if a non-zero timeout is
set, to match the behavior of only incrementing retries if a retry
value is set.

This way max retries & timeouts consistently take effect after a
tunable is set, rather than acting retroactively on a buffer which
has failed at some point in the past and has accumulated state from
those prior failures.

Thanks to dchinner for talking through this with me.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 10:54:09 +10:00
Eric Sandeen
0b4db5dff3 xfs: remove extraneous buffer flag changes
Fix up a couple places where extra flag manipulation occurs.

In the first case we clear XBF_ASYNC and then immediately reset it -
so don't bother clearing in the first place.

In the 2nd case we are at a point in the function where the buffer
must already be async, so there is no need to reset it.

Add consistent spacing around the " | " while we're at it.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 10:53:22 +10:00
Eric Sandeen
e97f6c545f xfs: fix xfs_error_get_cfg for negative errnos
xfs_error_get_cfg() is called with bp->b_error as an arg, which is
negative, so the switch statement won't ever find any matches.

This results in only the default error handler having any effect, as
EIO/ENOSPC/ENODEV get ignored due to the wrong sign.

It seems simplest to always flip the error sign to positive, so that
we can handle either negative errors in bp->b_error, or possibly a
positive errno via something like xfs_error_get_cfg(EIO) - this
future-proofs the function.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 10:48:51 +10:00
Hou Tao
ad70328a50 xfs: remove the magic numbers in xfs_btree_block-related len macros
replace the magic numbers by offsetof(...) and sizeof(...), and add two
extra checks on xfs_check_ondisk_structs()

[dchinner: renamed header structures to be more descriptive]

Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 10:43:11 +10:00