Pull btrfs fixes from Chris Mason:
"Zygo tracked down a very old bug with inline compressed extents.
I didn't tag this one for stable because I want to do individual
tested backports. It's a little tricky and I'd rather do some extra
testing on it along the way"
* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: add missing memset while reading compressed inline extents
Btrfs: fix regression in lock_delalloc_pages
btrfs: remove btrfs_err_str function from uapi/linux/btrfs.h
This patch adds to account free nids for each NAT blocks, and while
scanning all free nid bitmap, do check count and skip lookuping in
full NAT block.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This is to avoid build warning reported by kbuild test robot.
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes that SSR can overwrite previous warm node block consisting of
a node chain since the last checkpoint.
Fixes: 5b6c6be2d8 ("f2fs: use SSR for warm node as well")
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable Bugfixes:
- Fix decrementing nrequests in NFS v4.2 COPY to fix kernel warnings
- Prevent a double free in async nfs4_exchange_id()
- Squelch a kbuild sparse complaint for xprtrdma
Other Bugfixes:
- Fix a typo (NFS_ATTR_FATTR_GROUP_NAME) that causes a memory leak
- Fix a reference leak that causes kernel warnings
- Make nfs4_cb_sv_ops static to fix a sparse warning
- Respect a server's max size in CREATE_SESSION
- Handle errors from nfs4_pnfs_ds_connect
- Flexfiles layout shouldn't mark devices as unavailable
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Merge tag 'nfs-for-4.11-2' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client fixes from Anna Schumaker:
"We have a handful of stable fixes to fix kernel warnings and other
bugs that have been around for a while. We've also found a few other
reference counting bugs and memory leaks since the initial 4.11 pull.
Stable Bugfixes:
- Fix decrementing nrequests in NFS v4.2 COPY to fix kernel warnings
- Prevent a double free in async nfs4_exchange_id()
- Squelch a kbuild sparse complaint for xprtrdma
Other Bugfixes:
- Fix a typo (NFS_ATTR_FATTR_GROUP_NAME) that causes a memory leak
- Fix a reference leak that causes kernel warnings
- Make nfs4_cb_sv_ops static to fix a sparse warning
- Respect a server's max size in CREATE_SESSION
- Handle errors from nfs4_pnfs_ds_connect
- Flexfiles layout shouldn't mark devices as unavailable"
* tag 'nfs-for-4.11-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
pNFS/flexfiles: never nfs4_mark_deviceid_unavailable
pNFS: return status from nfs4_pnfs_ds_connect
NFSv4.1 respect server's max size in CREATE_SESSION
NFS prevent double free in async nfs4_exchange_id
nfs: make nfs4_cb_sv_ops static
xprtrdma: Squelch kbuild sparse complaint
NFS: fix the fault nrequests decreasing for nfs_inode COPY
NFSv4: fix a reference leak caused WARNING messages
nfs4: fix a typo of NFS_ATTR_FATTR_GROUP_NAME
This is a story about 4 distinct (and very old) btrfs bugs.
Commit c8b978188c ("Btrfs: Add zlib compression support") added
three data corruption bugs for inline extents (bugs #1-3).
Commit 93c82d5750 ("Btrfs: zero page past end of inline file items")
fixed bug #1: uncompressed inline extents followed by a hole and more
extents could get non-zero data in the hole as they were read. The fix
was to add a memset in btrfs_get_extent to zero out the hole.
Commit 166ae5a418 ("btrfs: fix inline compressed read err corruption")
fixed bug #2: compressed inline extents which contained non-zero bytes
might be replaced with zero bytes in some cases. This patch removed an
unhelpful memset from uncompress_inline, but the case where memset is
required was missed.
There is also a memset in the decompression code, but this only covers
decompressed data that is shorter than the ram_bytes from the extent
ref record. This memset doesn't cover the region between the end of the
decompressed data and the end of the page. It has also moved around a
few times over the years, so there's no single patch to refer to.
This patch fixes bug #3: compressed inline extents followed by a hole
and more extents could get non-zero data in the hole as they were read
(i.e. bug #3 is the same as bug #1, but s/uncompressed/compressed/).
The fix is the same: zero out the hole in the compressed case too,
by putting a memset back in uncompress_inline, but this time with
correct parameters.
The last and oldest bug, bug #0, is the cause of the offending inline
extent/hole/extent pattern. Bug #0 is a subtle and mostly-harmless quirk
of behavior somewhere in the btrfs write code. In a few special cases,
an inline extent and hole are allowed to persist where they normally
would be combined with later extents in the file.
A fast reproducer for bug #0 is presented below. A few offending extents
are also created in the wild during large rsync transfers with the -S
flag. A Linux kernel build (git checkout; make allyesconfig; make -j8)
will produce a handful of offending files as well. Once an offending
file is created, it can present different content to userspace each
time it is read.
Bug #0 is at least 4 and possibly 8 years old. I verified every vX.Y
kernel back to v3.5 has this behavior. There are fossil records of this
bug's effects in commits all the way back to v2.6.32. I have no reason
to believe bug #0 wasn't present at the beginning of btrfs compression
support in v2.6.29, but I can't easily test kernels that old to be sure.
It is not clear whether bug #0 is worth fixing. A fix would likely
require injecting extra reads into currently write-only paths, and most
of the exceptional cases caused by bug #0 are already handled now.
Whether we like them or not, bug #0's inline extents followed by holes
are part of the btrfs de-facto disk format now, and we need to be able
to read them without data corruption or an infoleak. So enough about
bug #0, let's get back to bug #3 (this patch).
An example of on-disk structure leading to data corruption found in
the wild:
item 61 key (606890 INODE_ITEM 0) itemoff 9662 itemsize 160
inode generation 50 transid 50 size 47424 nbytes 49141
block group 0 mode 100644 links 1 uid 0 gid 0
rdev 0 flags 0x0(none)
item 62 key (606890 INODE_REF 603050) itemoff 9642 itemsize 20
inode ref index 3 namelen 10 name: DB_File.so
item 63 key (606890 EXTENT_DATA 0) itemoff 8280 itemsize 1362
inline extent data size 1341 ram 4085 compress(zlib)
item 64 key (606890 EXTENT_DATA 4096) itemoff 8227 itemsize 53
extent data disk byte 5367308288 nr 20480
extent data offset 0 nr 45056 ram 45056
extent compression(zlib)
Different data appears in userspace during each read of the 11 bytes
between 4085 and 4096. The extent in item 63 is not long enough to
fill the first page of the file, so a memset is required to fill the
space between item 63 (ending at 4085) and item 64 (beginning at 4096)
with zero.
Here is a reproducer from Liu Bo, which demonstrates another method
of creating the same inline extent and hole pattern:
Using 'page_poison=on' kernel command line (or enable
CONFIG_PAGE_POISONING) run the following:
# touch foo
# chattr +c foo
# xfs_io -f -c "pwrite -W 0 1000" foo
# xfs_io -f -c "falloc 4 8188" foo
# od -x foo
# echo 3 >/proc/sys/vm/drop_caches
# od -x foo
This produce the following on my box:
Correct output: file contains 1000 data bytes followed
by zeros:
0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
*
0001740 cdcd cdcd cdcd cdcd 0000 0000 0000 0000
0001760 0000 0000 0000 0000 0000 0000 0000 0000
*
0020000
Actual output: the data after the first 1000 bytes
will be different each run:
0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
*
0001740 cdcd cdcd cdcd cdcd 6c63 7400 635f 006d
0001760 5f74 6f43 7400 435f 0053 5f74 7363 7400
0002000 435f 0056 5f74 6164 7400 645f 0062 5f74
(...)
Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Chris Mason <clm@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The bug is a regression after commit
(da2c7009f6 "btrfs: teach __process_pages_contig about PAGE_LOCK operation")
and commit
(76c0021db8 "Btrfs: use helper to simplify lock/unlock pages").
So if the dirty pages which are under writeback got truncated partially
before we lock the dirty pages, we couldn't find all pages mapping to the
delalloc range, and the bug didn't return an error so it kept going on and
found that the delalloc range got truncated and got to unlock the dirty
pages, and then the ASSERT could caught the error, and showed
-----------------------------------------------------------------------------
assertion failed: page_ops & PAGE_LOCK, file: fs/btrfs/extent_io.c, line: 1716
-----------------------------------------------------------------------------
This fixes the bug by returning the proper -EAGAIN.
Cc: David Sterba <dsterba@suse.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The flexfiles layout should never mark a device unavailable.
Move nfs4_mark_deviceid_unavailable out of nfs4_pnfs_ds_connect and call
directly from files layout where it's still needed.
The flexfiles driver still handles marked devices in error paths, but will
now print a rate limited warning.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The nfs4_pnfs_ds_connect path can call rpc_create which can fail or it
can wait on another context to reach the same failure.
This checks that the rpc_create succeeded and returns the error to the
caller.
When an error is returned, both the files and flexfiles layouts will return
NULL from _prepare_ds(). The flexfiles layout will also return the layout
with the error NFS4ERR_NXIO.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Currently client doesn't respect max sizes server returns in CREATE_SESSION.
nfs4_session_set_rwsize() gets called and server->rsize, server->wsize are 0
so they never get set to the sizes returned by the server.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Since rpc_task is async, the release function should be called which
will free the impl_id, scope, and owner.
Trond pointed at 2 more problems:
-- use of client pointer after free in the nfs4_exchangeid_release() function
-- cl_count mismatch if rpc_run_task() isn't run
Fixes: 8d89bd70bc ("NFS setup async exchange_id")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Cc: stable@vger.kernel.org # 4.9
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Fixes the following sparse warning:
fs/nfs/callback.c:235:21: warning: symbol 'nfs4_cb_sv_ops' was not
declared. Should it be static?
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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Merge tag 'afs-20170316' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS fixes from David Howells:
"Fixes to the AFS filesystem in the kernel.
They fix a variety of bugs. These include some issues fixed for
consistency with other AFS implementations:
- handle AFS mode bits better
- use the client mtime rather than the server mtime in the protocol
- handle the server returning more or less data than was requested in
a FetchData call
- distinguish mountpoints from symlinks based on the mode bits rather
than preemptively reading every symlink to find out what it
actually represents
One other notable change for the user is that files are now flushed on
close analogously with other network filesystems"
* tag 'afs-20170316' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (28 commits)
afs: Don't wait for page writeback with the page lock held
afs: ->writepage() shouldn't call clear_page_dirty_for_io()
afs: Fix abort on signal while waiting for call completion
afs: Fix an off-by-one error in afs_send_pages()
afs: Fix afs_kill_pages()
afs: Fix page leak in afs_write_begin()
afs: Don't set PG_error on local EINTR or ENOMEM when filling a page
afs: Populate and use client modification time
afs: Better abort and net error handling
afs: Invalid op ID should abort with RXGEN_OPCODE
afs: Fix the maths in afs_fs_store_data()
afs: Use a bvec rather than a kvec in afs_send_pages()
afs: Make struct afs_read::remain 64-bit
afs: Fix AFS read bug
afs: Prevent callback expiry timer overflow
afs: Migrate vlocation fields to 64-bit
afs: security: Replace rcu_assign_pointer() with RCU_INIT_POINTER()
afs: inode: Replace rcu_assign_pointer() with RCU_INIT_POINTER()
afs: Distinguish mountpoints from symlinks by file mode alone
afs: Flush outstanding writes when an fd is closed
...
Recently started seeing a kernel oops when a module tries removing a
memory mapped sysfs bin_attribute. On closer investigation the root
cause seems to be kernfs_release_file() trying to call
kernfs_op.release() callback that's NULL for such sysfs
bin_attributes. The oops occurs when kernfs_release_file() is called from
kernfs_drain_open_files() to cleanup any open handles with active
memory mappings.
The patch fixes this by checking for flag KERNFS_HAS_RELEASE before
calling kernfs_release_file() in function kernfs_drain_open_files().
On ppc64-le arch with cxl module the oops back-trace is of the
form below:
[ 861.381126] Unable to handle kernel paging request for instruction fetch
[ 861.381360] Faulting instruction address: 0x00000000
[ 861.381428] Oops: Kernel access of bad area, sig: 11 [#1]
....
[ 861.382481] NIP: 0000000000000000 LR: c000000000362c60 CTR:
0000000000000000
....
Call Trace:
[c000000f1680b750] [c000000000362c34] kernfs_drain_open_files+0x104/0x1d0 (unreliable)
[c000000f1680b790] [c00000000035fa00] __kernfs_remove+0x260/0x2c0
[c000000f1680b820] [c000000000360da0] kernfs_remove_by_name_ns+0x60/0xe0
[c000000f1680b8b0] [c0000000003638f4] sysfs_remove_bin_file+0x24/0x40
[c000000f1680b8d0] [c00000000062a164] device_remove_bin_file+0x24/0x40
[c000000f1680b8f0] [d000000009b7b22c] cxl_sysfs_afu_remove+0x144/0x170 [cxl]
[c000000f1680b940] [d000000009b7c7e4] cxl_remove+0x6c/0x1a0 [cxl]
[c000000f1680b990] [c00000000052f694] pci_device_remove+0x64/0x110
[c000000f1680b9d0] [c0000000006321d4] device_release_driver_internal+0x1f4/0x2b0
[c000000f1680ba20] [c000000000525cb0] pci_stop_bus_device+0xa0/0xd0
[c000000f1680ba60] [c000000000525e80] pci_stop_and_remove_bus_device+0x20/0x40
[c000000f1680ba90] [c00000000004a6c4] pci_hp_remove_devices+0x84/0xc0
[c000000f1680bad0] [c00000000004a688] pci_hp_remove_devices+0x48/0xc0
[c000000f1680bb10] [c0000000009dfda4] eeh_reset_device+0xb0/0x290
[c000000f1680bbb0] [c000000000032b4c] eeh_handle_normal_event+0x47c/0x530
[c000000f1680bc60] [c000000000032e64] eeh_handle_event+0x174/0x350
[c000000f1680bd10] [c000000000033228] eeh_event_handler+0x1e8/0x1f0
[c000000f1680bdc0] [c0000000000d384c] kthread+0x14c/0x190
[c000000f1680be30] [c00000000000b5a0] ret_from_kernel_thread+0x5c/0xbc
Fixes: f83f3c5156 ("kernfs: fix locking around kernfs_ops->release() callback")
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Validate inline directory data to prevent buffer overruns due to corrupt
metadata.
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Merge tag 'xfs-4.11-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fix from Darrick Wong:
"Here's a single fix for -rc3 to improve input validation on inline
directory data to prevent buffer overruns due to corrupt metadata"
* tag 'xfs-4.11-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: verify inline directory data forks
The ->writepage() op shouldn't call clear_page_dirty_for_io() as that has
already been called by the caller.
Fix afs_writepage() by moving the call out of
afs_write_back_from_locked_page() to afs_writepages_region() where it is
needed.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the way in which a call that's in progress and being waited for is
aborted in the case that EINTR is detected. We should be sending
RX_USER_ABORT rather than RX_CALL_DEAD as the abort code.
Note that since the only two ways out of the loop are if the call completes
or if a signal happens, the kill-the-call clause after the loop has
finished can only happen in the case of EINTR. This means that we only
have one abort case to deal with, not two, and the "KWC" case can never
happen and so can be deleted.
Note further that simply aborting the call isn't necessarily the best thing
here since at this point: the request has been entirely sent and it's
likely the server will do the operation anyway - whether we abort it or
not. In future, we should punt the handling of the remainder of the call
off to a background thread.
Reported-by: Marc Dionne <marc.c.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
afs_send_pages() should only put the call into the AFS_CALL_AWAIT_REPLY
state if it has sent all the pages - but the check it makes is incorrect
and sometimes it will finish the loop early.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix afs_kill_pages() in two ways:
(1) If a writeback has been partially flushed, then if we try and kill the
pages it contains, some of them may no longer be undergoing writeback
and end_page_writeback() will assert.
Fix this by checking to see whether the page in question is actually
undergoing writeback before ending that writeback.
(2) The loop that scans for pages to kill doesn't increase the first page
index, and so the loop may not terminate, but it will try to process
the same pages over and over again.
Fix this by increasing the first page index to one after the last page
we processed.
Signed-off-by: David Howells <dhowells@redhat.com>
afs_write_begin() leaks a ref and a lock on a page if afs_fill_page()
fails. Fix the leak by unlocking and releasing the page in the error path.
Signed-off-by: David Howells <dhowells@redhat.com>
The inode timestamps should be set from the client time
in the status received from the server, rather than the
server time which is meant for internal server use.
Set AFS_SET_MTIME and populate the mtime for operations
that take an input status, such as file/dir creation
and StoreData. If an input time is not provided the
server will set the vnode times based on the current server
time.
In a situation where the server has some skew with the
client, this could lead to the client seeing a timestamp
in the future for a file that it just created or wrote.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
If we receive a network error, a remote abort or a protocol error whilst
we're still transmitting data, make sure we return an appropriate error to
the caller rather than ESHUTDOWN or ECONNABORTED.
Signed-off-by: David Howells <dhowells@redhat.com>
When we are given an invalid operation ID, we should abort that with
RXGEN_OPCODE rather than RX_INVALID_OPERATION.
Also map RXGEN_OPCODE to -ENOTSUPP.
Signed-off-by: David Howells <dhowells@redhat.com>
afs_fs_store_data() works out of the size of the write it's going to make,
but it uses 32-bit unsigned subtraction in one place that gets
automatically cast to loff_t.
However, if to < offset, then the number goes negative, but as the result
isn't signed, this doesn't get sign-extended to 64-bits when placed in a
loff_t.
Fix by casting the operands to loff_t.
Signed-off-by: David Howells <dhowells@redhat.com>
Use a bvec rather than a kvec in afs_send_pages() as we don't then have to
call kmap() in advance. This allows us to pass the array of contiguous
pages that we extracted through to rxrpc in one go rather than passing a
single page at a time.
Signed-off-by: David Howells <dhowells@redhat.com>
Make struct afs_read::remain 64-bit so that it can handle huge transfers if
we ever request them or the server decides to give us a bit extra data (the
other fields there are already 64-bit).
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
get_seconds() returns real wall-clock seconds. On 32-bit systems
this value will overflow in year 2038 and beyond. This patch changes
afs_vnode record to use ktime_get_real_seconds() instead, for the
fields cb_expires and cb_expires_at.
Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
get_seconds() returns real wall-clock seconds. On 32-bit systems
this value will overflow in year 2038 and beyond. This patch changes
afs's vlocation record to use ktime_get_real_seconds() instead, for the
fields time_of_death and update_at.
Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.
The following Coccinelle semantic patch was used:
@@
@@
- rcu_assign_pointer
+ RCU_INIT_POINTER
(..., NULL)
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.
The following Coccinelle semantic patch was used:
@@
@@
- rcu_assign_pointer
+ RCU_INIT_POINTER
(..., NULL)
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
In AFS, mountpoints appear as symlinks with mode 0644 and normal symlinks
have mode 0777, so use this to distinguish them rather than reading the
content and parsing it. In the case of a mountpoint, the symlink body is a
formatted string indicating the location of the target volume.
Note that with this, kAFS no longer 'pre-fetches' the contents of symlinks,
so afs_readpage() may fail with an access-denial because when the VFS calls
d_automount(), it wraps the call in an credentials override that sets the
initial creds - thereby preventing access to the caller's keyrings and the
authentication keys held therein.
To this end, a patch reverting that change to the VFS is required also.
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Flush outstanding writes in afs when an fd is closed. This is what NFS and
CIFS do.
Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Handle the situation where afs_write_begin() is told to expect that a
full-page write will be made, but this doesn't happen (EFAULT, CTRL-C,
etc.), and so afs_write_end() sees a partial write took place. Currently,
no attempt is to deal with the discrepency.
Fix this by loading the gap from the server.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
When an AFS server is given an FS.FetchData{,64} request to read data from
a file, it is permitted by the protocol to return more or less than was
requested. kafs currently relies on the latter behaviour in readpage{,s}
to handle a partial page at the end of the file (we just ask for a whole
page and clear space beyond the short read).
However, we don't handle all cases. Add:
(1) Handle excess data by discarding it rather than aborting. Note that
we use a common static buffer to discard into so that the decryption
algorithm advances the PCBC state.
(2) Handle a short read that affects more than just the last page.
Note that if a read comes up unexpectedly short of long, it's possible that
the server's copy of the file changed - in which case the data version
number will have been incremented and the callback will have been broken -
in which case all the pages currently attached to the inode will be zapped
anyway at some point.
Signed-off-by: David Howells <dhowells@redhat.com>
Servers may send a callback array that is the same size as
the FID array, or an empty array. If the callback count is
0, the code would attempt to read (fid_count * 12) bytes of
data, which would fail and result in an unmarshalling error.
This would lead to stale data for remotely modified files
or directories.
Store the callback array size in the internal afs_call
structure and use that to determine the amount of data to
read.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Mode bits for an afs file should not be enforced in the usual
way.
For files, the absence of user bits can restrict file access
with respect to what is granted by the server.
These bits apply regardless of the owner or the current uid; the
rest of the mode bits (group, other) are ignored.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
The group was hard coded to GLOBAL_ROOT_GID; use the group
ID that was received from the server.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
afs_fill_page() loads the page it wants to fill into the afs_read request
without incrementing its refcount - but then calls afs_put_read() to clean
up afterwards, which then releases a ref on the page.
Fix this by getting a ref on the page before calling
afs_vnode_fetch_data().
This causes sync after a write to hang in afs_writepages_region() because
find_get_pages_tag() gets confused and doesn't return.
Fixes: 196ee9cd2d ("afs: Make afs_fs_fetch_data() take a list of pages")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
In afs_writepages_region(), inside the loop where we find dirty pages to
deal with, one of the if-statements is missing a put_page().
Signed-off-by: David Howells <dhowells@redhat.com>
Pull block fixes from Jens Axboe:
"Four small fixes for this cycle:
- followup fix from Neil for a fix that went in before -rc2, ensuring
that we always see the full per-task bio_list.
- fix for blk-mq-sched from me that ensures that we retain similar
direct-to-issue behavior on running the queue.
- fix from Sagi fixing a potential NULL pointer dereference in blk-mq
on spurious CPU unplug.
- a memory leak fix in writeback from Tahsin, fixing a case where
device removal of a mounted device can leak a struct
wb_writeback_work"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq-sched: don't run the queue async from blk_mq_try_issue_directly()
writeback: fix memory leak in wb_queue_work()
blk-mq: Fix tagset reinit in the presence of cpu hot-unplug
blk: Ensure users for current->bio_list can see the full list.
In journal_init_common(), if we failed to allocate the j_wbuf array, or
if we failed to create the buffer_head for the journal superblock, we
leaked the memory allocated for the revocation tables. Fix this.
Cc: stable@vger.kernel.org # 4.9
Fixes: f0c9fd5458
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
If ext4_convert_inline_data() was called on a directory with inline
data, the filesystem was left in an inconsistent state (as considered by
e2fsck) because the file size was not increased to cover the new block.
This happened because the inode was not marked dirty after i_disksize
was updated. Fix this by marking the inode dirty at the end of
ext4_finish_convert_inline_dir().
This bug was probably not noticed before because most users mark the
inode dirty afterwards for other reasons. But if userspace executed
FS_IOC_SET_ENCRYPTION_POLICY with invalid parameters, as exercised by
'kvm-xfstests -c adv generic/396', then the inode was never marked dirty
after updating i_disksize.
Cc: stable@vger.kernel.org # 3.10+
Fixes: 3c47d54170
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The only use of the ->prepare_context() fscrypt operation was to allow
ext4 to evict inline data from the inode before ->set_context().
However, there is no reason why this cannot be done as simply the first
step in ->set_context(), and in fact it makes more sense to do it that
way because then the policy modes and flags get validated before any
real work is done. Therefore, merge ext4_prepare_context() into
ext4_set_context(), and remove ->prepare_context().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Filesystem encryption ostensibly supported revoking a keyring key that
had been used to "unlock" encrypted files, causing those files to become
"locked" again. This was, however, buggy for several reasons, the most
severe of which was that when key revocation happened to be detected for
an inode, its fscrypt_info was immediately freed, even while other
threads could be using it for encryption or decryption concurrently.
This could be exploited to crash the kernel or worse.
This patch fixes the use-after-free by removing the code which detects
the keyring key having been revoked, invalidated, or expired. Instead,
an encrypted inode that is "unlocked" now simply remains unlocked until
it is evicted from memory. Note that this is no worse than the case for
block device-level encryption, e.g. dm-crypt, and it still remains
possible for a privileged user to evict unused pages, inodes, and
dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by
simply unmounting the filesystem. In fact, one of those actions was
already needed anyway for key revocation to work even somewhat sanely.
This change is not expected to break any applications.
In the future I'd like to implement a real API for fscrypt key
revocation that interacts sanely with ongoing filesystem operations ---
waiting for existing operations to complete and blocking new operations,
and invalidating and sanitizing key material and plaintext from the VFS
caches. But this is a hard problem, and for now this bug must be fixed.
This bug affected almost all versions of ext4, f2fs, and ubifs
encryption, and it was potentially reachable in any kernel configured
with encryption support (CONFIG_EXT4_ENCRYPTION=y,
CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
CONFIG_UBIFS_FS_ENCRYPTION=y). Note that older kernels did not use the
shared fs/crypto/ code, but due to the potential security implications
of this bug, it may still be worthwhile to backport this fix to them.
Fixes: b7236e21d5 ("ext4 crypto: reorganize how we store keys in the inode")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Michael Halcrow <mhalcrow@google.com>
Commit 88ffbf3e03 switches to using rhashtables for glocks, hashing over
the entire struct lm_lockname instead of its individual fields. On some
architectures, struct lm_lockname contains a hole of uninitialized
memory due to alignment rules, which now leads to incorrect hash values.
Get rid of that hole.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
CC: <stable@vger.kernel.org> #v4.3+
When we're reading or writing the data fork of an inline directory,
check the contents to make sure we're not overflowing buffers or eating
garbage data. xfs/348 corrupts an inline symlink into an inline
directory, triggering a buffer overflow bug.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---
v2: add more checks consistent with _dir2_sf_check and make the verifier
usable from anywhere.
Pull networking fixes from David Miller:
1) Ensure that mtu is at least IPV6_MIN_MTU in ipv6 VTI tunnel driver,
from Steffen Klassert.
2) Fix crashes when user tries to get_next_key on an LPM bpf map, from
Alexei Starovoitov.
3) Fix detection of VLAN fitlering feature for bnx2x VF devices, from
Michal Schmidt.
4) We can get a divide by zero when TCP socket are morphed into
listening state, fix from Eric Dumazet.
5) Fix socket refcounting bugs in skb_complete_wifi_ack() and
skb_complete_tx_timestamp(). From Eric Dumazet.
6) Use after free in dccp_feat_activate_values(), also from Eric
Dumazet.
7) Like bonding team needs to use ETH_MAX_MTU as netdev->max_mtu, from
Jarod Wilson.
8) Fix use after free in vrf_xmit(), from David Ahern.
9) Don't do UDP Fragmentation Offload on IPComp ipsec packets, from
Alexey Kodanev.
10) Properly check napi_complete_done() return value in order to decide
whether to re-enable IRQs or not in amd-xgbe driver, from Thomas
Lendacky.
11) Fix double free of hwmon device in marvell phy driver, from Andrew
Lunn.
12) Don't crash on malformed netlink attributes in act_connmark, from
Etienne Noss.
13) Don't remove routes with a higher metric in ipv6 ECMP route replace,
from Sabrina Dubroca.
14) Don't write into a cloned SKB in ipv6 fragmentation handling, from
Florian Westphal.
15) Fix routing redirect races in dccp and tcp, basically the ICMP
handler can't modify the socket's cached route in it's locked by the
user at this moment. From Jon Maxwell.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (108 commits)
qed: Enable iSCSI Out-of-Order
qed: Correct out-of-bound access in OOO history
qed: Fix interrupt flags on Rx LL2
qed: Free previous connections when releasing iSCSI
qed: Fix mapping leak on LL2 rx flow
qed: Prevent creation of too-big u32-chains
qed: Align CIDs according to DORQ requirement
mlxsw: reg: Fix SPVMLR max record count
mlxsw: reg: Fix SPVM max record count
net: Resend IGMP memberships upon peer notification.
dccp: fix memory leak during tear-down of unsuccessful connection request
tun: fix premature POLLOUT notification on tun devices
dccp/tcp: fix routing redirect race
ucc/hdlc: fix two little issue
vxlan: fix ovs support
net: use net->count to check whether a netns is alive or not
bridge: drop netfilter fake rtable unconditionally
ipv6: avoid write to a possibly cloned skb
net: wimax/i2400m: fix NULL-deref at probe
isdn/gigaset: fix NULL-deref at probe
...
When WB_registered flag is not set, wb_queue_work() skips queuing the
work, but does not perform the necessary clean up. In particular, if
work->auto_free is true, it should free the memory.
The leak condition can be reprouced by following these steps:
mount /dev/sdb /mnt/sdb
/* In qemu console: device_del sdb */
umount /dev/sdb
Above will result in a wb_queue_work() call on an unregistered wb and
thus leak memory.
Reported-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
If you write "-2 -3 -4" to the "versions" file, it will
notice that no versions are enabled, and nfsd_reset_versions()
is called.
This enables all major versions, not no minor versions.
So we lose the invariant that NFSv4 is only advertised when
at least one minor is enabled.
Fix the code to explicitly enable minor versions for v4,
change it to use nfsd_vers() to test and set, and simplify
the code.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Current code will return 1 if the version is supported,
and -1 if it isn't.
This is confusing and inconsistent with the one place where this
is used.
So change to return 1 if it is supported, and zero if not.
i.e. an error is never returned.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Prior to
e35659f1b0 ("NFSD: correctly range-check v4.x minor version when setting versions.")
v4.0 could not be disabled without disabling all NFSv4 protocols.
So the 'versions' file contained ±4 ±4.1 ±4.2.
Writing "-4" would disable all v4 completely. Writing +4 would enabled those
minor versions that are currently enabled, either by default or otherwise.
After that commit, it was possible to disable v4.0 independently. To
maximize backward compatibility with use cases which never disabled
v4.0, the "versions" file would never contain "+4.0" - that was implied
by "+4", unless explicitly negated by "-4.0".
This introduced an inconsistency in that it was possible to disable all
minor versions, but still have the major version advertised.
e.g. "-4.0 -4.1 -4.2 +4" would result in NFSv4 support being advertised,
but all attempts to use it rejected.
Commit
d3635ff07e ("nfsd: fix configuration of supported minor versions")
and following removed this inconsistency. If all minor version were disabled,
the major would be disabled too. If any minor was enabled, the major would be
disabled.
This patch also treated "+4" as equivalent to "+4.0" and "-4" as "-4.0".
A consequence of this is that writing "-4" would only disable 4.0.
This is a regression against the earlier behaviour, in a use case that rpc.nfsd
actually uses.
The command "rpc.nfsd -N 4" will write "+2 +3 -4" to the versions files.
Previously, that would disable v4 completely. Now it will only disable v4.0.
Also "4.0" never appears in the "versions" file when read.
So if only v4.1 is available, the previous kernel would have reported
"+4 -4.0 +4.1 -4.2" the current kernel reports "-4 +4.1 -4.2" which
could easily confuse.
This patch restores the implication that "+4" and "-4" apply more
globals and do not imply "4.0".
Specifically:
writing "-4" will disable all 4.x minor versions.
writing "+4" will enable all 4.1 minor version if none are currently enabled.
rpc.nfsd will list minor versions before major versions, so
rpc.nfsd -V 4.2 -N 4.1
will write "-4.1 +4.2 +2 +3 +4"
so it would be a regression for "+4" to enable always all versions.
reading "-4" implies that no v4.x are enabled
reading "+4" implies that some v4.x are enabled, and that v4.0 is enabled unless
"-4.0" is also present. All other minor versions will explicitly be listed.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Merge 5-level page table prep from Kirill Shutemov:
"Here's relatively low-risk part of 5-level paging patchset. Merging it
now will make x86 5-level paging enabling in v4.12 easier.
The first patch is actually x86-specific: detect 5-level paging
support. It boils down to single define.
The rest of patchset converts Linux MMU abstraction from 4- to 5-level
paging.
Enabling of new abstraction in most cases requires adding single line
of code in arch-specific code. The rest is taken care by asm-generic/.
Changes to mm/ code are mostly mechanical: add support for new page
table level -- p4d_t -- where we deal with pud_t now.
v2:
- fix build on microblaze (Michal);
- comment for __ARCH_HAS_5LEVEL_HACK in kasan_populate_zero_shadow();
- acks from Michal"
* emailed patches from Kirill A Shutemov <kirill.shutemov@linux.intel.com>:
mm: introduce __p4d_alloc()
mm: convert generic code to 5-level paging
asm-generic: introduce <asm-generic/pgtable-nop4d.h>
arch, mm: convert all architectures to use 5level-fixup.h
asm-generic: introduce __ARCH_USE_5LEVEL_HACK
asm-generic: introduce 5level-fixup.h
x86/cpufeature: Add 5-level paging detection
Merge fixes from Andrew Morton:
"26 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (26 commits)
userfaultfd: remove wrong comment from userfaultfd_ctx_get()
fat: fix using uninitialized fields of fat_inode/fsinfo_inode
sh: cayman: IDE support fix
kasan: fix races in quarantine_remove_cache()
kasan: resched in quarantine_remove_cache()
mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
thp: fix another corner case of munlock() vs. THPs
rmap: fix NULL-pointer dereference on THP munlocking
mm/memblock.c: fix memblock_next_valid_pfn()
userfaultfd: selftest: vm: allow to build in vm/ directory
userfaultfd: non-cooperative: userfaultfd_remove revalidate vma in MADV_DONTNEED
userfaultfd: non-cooperative: fix fork fctx->new memleak
mm/cgroup: avoid panic when init with low memory
drivers/md/bcache/util.h: remove duplicate inclusion of blkdev.h
mm/vmstats: add thp_split_pud event for clarity
include/linux/fs.h: fix unsigned enum warning with gcc-4.2
userfaultfd: non-cooperative: release all ctx in dup_userfaultfd_complete
userfaultfd: non-cooperative: robustness check
userfaultfd: non-cooperative: rollback userfaultfd_exit
x86, mm: unify exit paths in gup_pte_range()
...
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.
The theory lockdep comes up with is as follows:
(1) If the pagefault handler decides it needs to read pages from AFS, it
calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
creating a call requires the socket lock:
mmap_sem must be taken before sk_lock-AF_RXRPC
(2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind()
binds the underlying UDP socket whilst holding its socket lock.
inet_bind() takes its own socket lock:
sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET
(3) Reading from a TCP socket into a userspace buffer might cause a fault
and thus cause the kernel to take the mmap_sem, but the TCP socket is
locked whilst doing this:
sk_lock-AF_INET must be taken before mmap_sem
However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks. The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace. This is
a limitation in the design of lockdep.
Fix the general case by:
(1) Double up all the locking keys used in sockets so that one set are
used if the socket is created by userspace and the other set is used
if the socket is created by the kernel.
(2) Store the kern parameter passed to sk_alloc() in a variable in the
sock struct (sk_kern_sock). This informs sock_lock_init(),
sock_init_data() and sk_clone_lock() as to the lock keys to be used.
Note that the child created by sk_clone_lock() inherits the parent's
kern setting.
(3) Add a 'kern' parameter to ->accept() that is analogous to the one
passed in to ->create() that distinguishes whether kernel_accept() or
sys_accept4() was the caller and can be passed to sk_alloc().
Note that a lot of accept functions merely dequeue an already
allocated socket. I haven't touched these as the new socket already
exists before we get the parameter.
Note also that there are a couple of places where I've made the accepted
socket unconditionally kernel-based:
irda_accept()
rds_rcp_accept_one()
tcp_accept_from_sock()
because they follow a sock_create_kern() and accept off of that.
Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal. I wonder if these should do that so
that they use the new set of lock keys.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- Fix various iomap bugs
- Fix overly aggressive CoW preallocation garbage collection
- Fixes to CoW endio error handling
- Fix some incorrect geometry calculations
- Remove a potential system hang in bulkstat
- Try to allocate blocks more aggressively to reduce ENOSPC errors
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Merge tag 'xfs-4.11-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong:
"Here are some bug fixes for -rc2 to clean up the copy on write
handling and to remove a cause of hangs.
- Fix various iomap bugs
- Fix overly aggressive CoW preallocation garbage collection
- Fixes to CoW endio error handling
- Fix some incorrect geometry calculations
- Remove a potential system hang in bulkstat
- Try to allocate blocks more aggressively to reduce ENOSPC errors"
* tag 'xfs-4.11-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: try any AG when allocating the first btree block when reflinking
xfs: use iomap new flag for newly allocated delalloc blocks
xfs: remove kmem_zalloc_greedy
xfs: Use xfs_icluster_size_fsb() to calculate inode alignment mask
xfs: fix and streamline error handling in xfs_end_io
xfs: only reclaim unwritten COW extents periodically
iomap: invalidate page caches should be after iomap_dio_complete() in direct write
It's a void function, so there is no return value;
Link: http://lkml.kernel.org/r/20170309150817.7510-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recently fallocate patch was merged and it uses
MSDOS_I(inode)->mmu_private at fat_evict_inode(). However,
fat_inode/fsinfo_inode that was introduced in past didn't initialize
MSDOS_I(inode) properly.
With those combinations, it became the cause of accessing random entry
in FAT area.
Link: http://lkml.kernel.org/r/87pohrj4i8.fsf@mail.parknet.co.jp
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Moreno Bartalucci <moreno.bartalucci@tecnorama.it>
Tested-by: Moreno Bartalucci <moreno.bartalucci@tecnorama.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
userfaultfd_remove() has to be execute before zapping the pagetables or
UFFDIO_COPY could keep filling pages after zap_page_range returned,
which would result in non zero data after a MADV_DONTNEED.
However userfaultfd_remove() may have to release the mmap_sem. This was
handled correctly in MADV_REMOVE, but MADV_DONTNEED accessed a
potentially stale vma (the very vma passed to zap_page_range(vma, ...)).
The fix consists in revalidating the vma in case userfaultfd_remove()
had to release the mmap_sem.
This also optimizes away an unnecessary down_read/up_read in the
MADV_REMOVE case if UFFD_EVENT_FORK had to be delivered.
It all remains zero runtime cost in case CONFIG_USERFAULTFD=n as
userfaultfd_remove() will be defined as "true" at build time.
Link: http://lkml.kernel.org/r/20170302173738.18994-3-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have a memleak in the ->new ctx if the uffd of the parent is closed
before the fork event is read, nothing frees the new context.
Link: http://lkml.kernel.org/r/20170302173738.18994-2-aarcange@redhat.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't stop running dup_fctx() even if userfaultfd_event_wait_completion
fails as it has to run userfaultfd_ctx_put on all ctx to pair against
the userfaultfd_ctx_get that was run on all fctx->orig in
dup_userfaultfd.
Link: http://lkml.kernel.org/r/20170224181957.19736-4-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Similar to the handle_userfault() case, also make sure to never attempt
to send any event past the PF_EXITING point of no return.
This is purely a robustness check.
Link: http://lkml.kernel.org/r/20170224181957.19736-3-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "userfaultfd non-cooperative further update for 4.11 merge
window".
Unfortunately I noticed one relevant bug in userfaultfd_exit while doing
more testing. I've been doing testing before and this was also tested
by kbuild bot and exercised by the selftest, but this bug never
reproduced before.
I dropped userfaultfd_exit as result. I dropped it because of
implementation difficulty in receiving signals in __mmput and because I
think -ENOSPC as result from the background UFFDIO_COPY should be enough
already.
Before I decided to remove userfaultfd_exit, I noticed userfaultfd_exit
wasn't exercised by the selftest and when I tried to exercise it, after
moving it to a more correct place in __mmput where it would make more
sense and where the vma list is stable, it resulted in the
event_wait_completion in D state. So then I added the second patch to
be sure even if we call userfaultfd_event_wait_completion too late
during task exit(), we won't risk to generate tasks in D state. The
same check exists in handle_userfault() for the same reason, except it
makes a difference there, while here is just a robustness check and it's
run under WARN_ON_ONCE.
While looking at the userfaultfd_event_wait_completion() function I
looked back at its callers too while at it and I think it's not ok to
stop executing dup_fctx on the fcs list because we relay on
userfaultfd_event_wait_completion to execute
userfaultfd_ctx_put(fctx->orig) which is paired against
userfaultfd_ctx_get(fctx->orig) in dup_userfault just before
list_add(fcs). This change only takes care of fctx->orig but this area
also needs further review looking for similar problems in fctx->new.
The only patch that is urgent is the first because it's an use after
free during a SMP race condition that affects all processes if
CONFIG_USERFAULTFD=y. Very hard to reproduce though and probably
impossible without SLUB poisoning enabled.
This patch (of 3):
I once reproduced this oops with the userfaultfd selftest, it's not
easily reproducible and it requires SLUB poisoning to reproduce.
general protection fault: 0000 [#1] SMP
Modules linked in:
CPU: 2 PID: 18421 Comm: userfaultfd Tainted: G ------------ T 3.10.0+ #15
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014
task: ffff8801f83b9440 ti: ffff8801f833c000 task.ti: ffff8801f833c000
RIP: 0010:[<ffffffff81451299>] [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0
RSP: 0018:ffff8801f833fe80 EFLAGS: 00010202
RAX: ffff8801f833ffd8 RBX: 6b6b6b6b6b6b6b6b RCX: ffff8801f83b9440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800baf18600
RBP: ffff8801f833fee8 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff8127ceb3 R12: 0000000000000000
R13: ffff8800baf186b0 R14: ffff8801f83b99f8 R15: 00007faed746c700
FS: 0000000000000000(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007faf0966f028 CR3: 0000000001bc6000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
do_exit+0x297/0xd10
SyS_exit+0x17/0x20
tracesys+0xdd/0xe2
Code: 00 00 66 66 66 66 90 55 48 89 e5 41 54 53 48 83 ec 58 48 8b 1f 48 85 db 75 11 eb 73 66 0f 1f 44 00 00 48 8b 5b 10 48 85 db 74 64 <4c> 8b a3 b8 00 00 00 4d 85 e4 74 eb 41 f6 84 24 2c 01 00 00 80
RIP [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0
RSP <ffff8801f833fe80>
---[ end trace 9fecd6dcb442846a ]---
In the debugger I located the "mm" pointer in the stack and walking
mm->mmap->vm_next through the end shows the vma->vm_next list is fully
consistent and it is null terminated list as expected. So this has to
be an SMP race condition where userfaultfd_exit was running while the
vma list was being modified by another CPU.
When userfaultfd_exit() run one of the ->vm_next pointers pointed to
SLAB_POISON (RBX is the vma pointer and is 0x6b6b..).
The reason is that it's not running in __mmput but while there are still
other threads running and it's not holding the mmap_sem (it can't as it
has to wait the even to be received by the manager). So this is an use
after free that was happening for all processes.
One more implementation problem aside from the race condition:
userfaultfd_exit has really to check a flag in mm->flags before walking
the vma or it's going to slowdown the exit() path for regular tasks.
One more implementation problem: at that point signals can't be
delivered so it would also create a task in D state if the manager
doesn't read the event.
The major design issue: it overall looks superfluous as the manager can
check for -ENOSPC in the background transfer:
if (mmget_not_zero(ctx->mm)) {
[..]
} else {
return -ENOSPC;
}
It's safer to roll it back and re-introduce it later if at all.
[rppt@linux.vnet.ibm.com: documentation fixup after removal of UFFD_EVENT_EXIT]
Link: http://lkml.kernel.org/r/1488345437-4364-1-git-send-email-rppt@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/20170224181957.19736-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__do_fault assumes vmf->page has been initialized and is valid if
VM_FAULT_NOPAGE is not returned by vma->vm_ops->fault(vma, vmf).
handle_userfault() in turn should return VM_FAULT_NOPAGE if it doesn't
return VM_FAULT_SIGBUS or VM_FAULT_RETRY (the other two possibilities).
This VM_FAULT_NOPAGE case is only invoked when signal are pending and it
didn't matter for anonymous memory before. It only started to matter
since shmem was introduced. hugetlbfs also takes a different path and
doesn't exercise __do_fault.
Link: http://lkml.kernel.org/r/20170228154201.GH5816@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert all non-architecture-specific code to 5-level paging.
It's mostly mechanical adding handling one more page table level in
places where we deal with pud_t.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes the extra include header file that was added in commit
e58bc92783 "Pull overlayfs updates from Miklos Szeredi" now that it
is no longer needed.
There are probably other such includes that got added during the
scheduler header splitup series, but this is the one that annoyed me
personally and I know about.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a reflink operation causes the bmap code to allocate a btree block
we're currently doing single-AG allocations due to having ->firstblock
set and then try any higher AG due a little reflink quirk we've put in
when adding the reflink code. But given that we do not have a minleft
reservation of any kind in this AG we can still not have any space in
the same or higher AG even if the file system has enough free space.
To fix this use a XFS_ALLOCTYPE_FIRST_AG allocation in this fall back
path instead.
[And yes, we need to redo this properly instead of piling hacks over
hacks. I'm working on that, but it's not going to be a small series.
In the meantime this fixes the customer reported issue]
Also add a warning for failing allocations to make it easier to debug.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Commit fa7f138 ("xfs: clear delalloc and cache on buffered write
failure") fixed one regression in the iomap error handling code and
exposed another. The fundamental problem is that if a buffered write
is a rewrite of preexisting delalloc blocks and the write fails, the
failure handling code can punch out preexisting blocks with valid
file data.
This was reproduced directly by sub-block writes in the LTP
kernel/syscalls/write/write03 test. A first 100 byte write allocates
a single block in a file. A subsequent 100 byte write fails and
punches out the block, including the data successfully written by
the previous write.
To address this problem, update the ->iomap_begin() handler to
distinguish newly allocated delalloc blocks from preexisting
delalloc blocks via the IOMAP_F_NEW flag. Use this flag in the
->iomap_end() handler to decide when a failed or short write should
punch out delalloc blocks.
This introduces the subtle requirement that ->iomap_begin() should
never combine newly allocated delalloc blocks with existing blocks
in the resulting iomap descriptor. This can occur when a new
delalloc reservation merges with a neighboring extent that is part
of the current write, for example. Therefore, drop the
post-allocation extent lookup from xfs_bmapi_reserve_delalloc() and
just return the record inserted into the fork. This ensures only new
blocks are returned and thus that preexisting delalloc blocks are
always handled as "found" blocks and not punched out on a failed
rewrite.
Reported-by: Xiong Zhou <xzhou@redhat.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The sole remaining caller of kmem_zalloc_greedy is bulkstat, which uses
it to grab 1-4 pages for staging of inobt records. The infinite loop in
the greedy allocation function is causing hangs[1] in generic/269, so
just get rid of the greedy allocator in favor of kmem_zalloc_large.
This makes bulkstat somewhat more likely to ENOMEM if there's really no
pages to spare, but eliminates a source of hangs.
[1] http://lkml.kernel.org/r/20170301044634.rgidgdqqiiwsmfpj%40XZHOUW.usersys.redhat.com
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
v2: remove single-page fallback
When block size is larger than inode cluster size, the call to
XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size) returns 0. Also, mkfs.xfs
would have set xfs_sb->sb_inoalignmt to 0. Hence in
xfs_set_inoalignment(), xfs_mount->m_inoalign_mask gets initialized to
-1 instead of 0. However, xfs_mount->m_sinoalign would get correctly
intialized to 0 because for every positive value of xfs_mount->m_dalign,
the condition "!(mp->m_dalign & mp->m_inoalign_mask)" would evaluate to
false.
Also, xfs_imap() worked fine even with xfs_mount->m_inoalign_mask having
-1 as the value because blks_per_cluster variable would have the value 1
and hence we would never have a need to use xfs_mount->m_inoalign_mask
to compute the inode chunk's agbno and offset within the chunk.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
There are two different cases of buffered I/O errors:
- first we can have an already shutdown fs. In that case we should skip
any on-disk operations and just clean up the appen transaction if
present and destroy the ioend
- a real I/O error. In that case we should cleanup any lingering COW
blocks. This gets skipped in the current code and is fixed by this
patch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
We only want to reclaim preallocations from our periodic work item.
Currently this is archived by looking for a dirty inode, but that check
is rather fragile. Instead add a flag to xfs_reflink_cancel_cow_* so
that the caller can ask for just cancelling unwritten extents in the COW
fork.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: fix typos in commit message]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Pull timer fixes from Ingo Molnar:
"This includes a fix for lockups caused by incorrect nsecs related
cleanup, and a capabilities check fix for timerfd"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC
timerfd: Only check CAP_WAKE_ALARM when it is needed
After XFS switching to iomap based DIO (commit acdda3aae1 ("xfs:
use iomap_dio_rw")), I started to notice dio29/dio30 tests failures
from LTP run on ppc64 hosts, and they can be reproduced on x86_64
hosts with 512B/1k block size XFS too.
dio29 diotest3 -b 65536 -n 100 -i 1000 -o 1024000
dio30 diotest6 -b 65536 -n 100 -i 1000 -o 1024000
The failure message is like:
bufcmp: offset 0: Expected: 0x62, got 0x0
diotest03 1 TPASS : Read with Direct IO, Write without
diotest03 2 TFAIL : diotest3.c:142: comparsion failed; child=98 offset=1425408
diotest03 3 TFAIL : diotest3.c:194: Write Direct-child 98 failed
Direct write wrote 0x62 but buffer read got zero. This is because,
when doing direct write to a hole or preallocated file, we
invalidate the page caches before converting the extent from
unwritten state to normal state, which is done by
iomap_dio_complete(), thus leave a window for other buffer reader to
cache the unwritten state extent.
Consider this case, with sub-page blocksize XFS, two processes are
direct writing to different blocksize-aligned regions (say 512B) of
the same preallocated file, and reading the region back via buffered
I/O to compare contents.
process A, region [0,512] process B, region [512,1024]
xfs_file_write_iter
xfs_file_aio_dio_write
iomap_dio_rw
iomap_apply
invalidate_inode_pages2_range
xfs_file_write_iter
xfs_file_aio_dio_write
iomap_dio_rw
iomap_apply
invalidate_inode_pages2_range
iomap_dio_complete
xfs_file_read_iter
xfs_file_buffered_aio_read
generic_file_read_iter
do_generic_file_read
<readahead fills pagecache with 0>
iomap_dio_complete
xfs_file_read_iter
<read gets 0 from pagecache>
Process A first invalidates page caches, at this point the
underlying extent is still in unwritten state (iomap_dio_complete
not called yet), and process B finishs direct write and populates
page caches via readahead, which caches zeros in page for region A,
then process A reads zeros from page cache, instead of the actual
data.
Fix it by invalidating page caches after converting unwritten extent
to make sure we read content from disk after extent state changed,
as what we did before switching to iomap based dio.
Also introduce a new 'start' variable to save the original write
offset (iomap_dio_complete() updates iocb->ki_pos), and a 'err'
variable for invalidating caches result, cause we can't reuse 'ret'
anymore.
Signed-off-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Pull misc final vfs updates from Al Viro:
"A few unrelated patches that got beating in -next.
Everything else will have to go into the next window ;-/"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
hfs: fix hfs_readdir()
selftest for default_file_splice_read() infoleak
9p: constify ->d_name handling
Pull SMB3 fixes from Steve French:
"Some small bug fixes as well as SMB2.1/SMB3 enablement for DFS (global
namespace) which previously was only enabled for CIFS"
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
smb2: Enforce sec= mount option
CIFS: Fix sparse warnings
CIFS: implement get_dfs_refer for SMB2+
CIFS: use DFS pathnames in SMB2+ Create requests
CIFS: set signing flag in SMB2+ TreeConnect if needed
CIFS: let ses->ipc_tid hold smb2 TreeIds
CIFS: add use_ipc flag to SMB2_ioctl()
CIFS: add build_path_from_dentry_optional_prefix()
CIFS: move DFS response parsing out of SMB1 code
CIFS: Fix possible use after free in demultiplex thread
Pull overlayfs updates from Miklos Szeredi:
"Because copy up can take a long time, serialized copy ups could be a
big performance bottleneck. This update allows concurrent copy up of
regular files eliminating this potential problem.
There are also minor fixes"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: drop CAP_SYS_RESOURCE from saved mounter's credentials
ovl: properly implement sync_filesystem()
ovl: concurrent copy up of regular files
ovl: introduce copy up waitqueue
ovl: copy up regular file using O_TMPFILE
ovl: rearrange code in ovl_copy_up_locked()
ovl: check if upperdir fs supports O_TMPFILE
Pull vfs 'statx()' update from Al Viro.
This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.
It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?
From David Howells.
Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:
https://www.spinics.net/lists/linux-fsdevel/msg33831.html
* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
statx: Add a system call to make enhanced file info available
Pull block layer fixes from Jens Axboe:
"A collection of fixes for this merge window, either fixes for existing
issues, or parts that were waiting for acks to come in. This pull
request contains:
- Allocation of nvme queues on the right node from Shaohua.
This was ready long before the merge window, but waiting on an ack
from Bjorn on the PCI bit. Now that we have that, the three patches
can go in.
- Two fixes for blk-mq-sched with nvmeof, which uses hctx specific
request allocations. This caused an oops. One part from Sagi, one
part from Omar.
- A loop partition scan deadlock fix from Omar, fixing a regression
in this merge window.
- A three-patch series from Keith, closing up a hole on clearing out
requests on shutdown/resume.
- A stable fix for nbd from Josef, fixing a leak of sockets.
- Two fixes for a regression in this window from Jan, fixing a
problem with one of his earlier patches dealing with queue vs bdi
life times.
- A fix for a regression with virtio-blk, causing an IO stall if
scheduling is used. From me.
- A fix for an io context lock ordering problem. From me"
* 'for-linus' of git://git.kernel.dk/linux-block:
block: Move bdi_unregister() to del_gendisk()
blk-mq: ensure that bd->last is always set correctly
block: don't call ioc_exit_icq() with the queue lock held for blk-mq
block: Initialize bd_bdi on inode initialization
loop: fix LO_FLAGS_PARTSCAN hang
nvme: Complete all stuck requests
blk-mq: Provide freeze queue timeout
blk-mq: Export blk_mq_freeze_queue_wait
nbd: stop leaking sockets
blk-mq: move update of tags->rqs to __blk_mq_alloc_request()
blk-mq: kill blk_mq_set_alloc_data()
blk-mq: make blk_mq_alloc_request_hctx() allocate a scheduler request
blk-mq-sched: Allocate sched reserved tags as specified in the original queue tagset
nvme: allocate nvme_queue in correct node
PCI: add an API to get node from vector
blk-mq: allocate blk_mq_tags and requests in correct node
Pull sched.h split-up from Ingo Molnar:
"The point of these changes is to significantly reduce the
<linux/sched.h> header footprint, to speed up the kernel build and to
have a cleaner header structure.
After these changes the new <linux/sched.h>'s typical preprocessed
size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K
lines), which is around 40% faster to build on typical configs.
Not much changed from the last version (-v2) posted three weeks ago: I
eliminated quirks, backmerged fixes plus I rebased it to an upstream
SHA1 from yesterday that includes most changes queued up in -next plus
all sched.h changes that were pending from Andrew.
I've re-tested the series both on x86 and on cross-arch defconfigs,
and did a bisectability test at a number of random points.
I tried to test as many build configurations as possible, but some
build breakage is probably still left - but it should be mostly
limited to architectures that have no cross-compiler binaries
available on kernel.org, and non-default configurations"
* 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits)
sched/headers: Clean up <linux/sched.h>
sched/headers: Remove #ifdefs from <linux/sched.h>
sched/headers: Remove the <linux/topology.h> include from <linux/sched.h>
sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h>
sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h>
sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h>
sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h>
sched/headers: Remove <linux/sched.h> from <linux/sched/init.h>
sched/core: Remove unused prefetch_stack()
sched/headers: Remove <linux/rculist.h> from <linux/sched.h>
sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h>
sched/headers: Remove <linux/signal.h> from <linux/sched.h>
sched/headers: Remove <linux/rwsem.h> from <linux/sched.h>
sched/headers: Remove the runqueue_is_locked() prototype
sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h>
sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h>
sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h>
sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h>
sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h>
sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h>
...
If the security type specified using a mount option is not supported,
the SMB2 session setup code changes the security type to RawNTLMSSP. We
should instead fail the mount and return an error.
The patch changes the code for SMB2 to make it similar to the code used
for SMB1. Like in SMB1, we now use the global security flags to select
the security method to be used when no security method is specified and
to return an error when the requested auth method is not available.
For SMB2, we also use ntlmv2 as a synonym for nltmssp.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Fix two minor sparse compile check warnings
Signed-off-by: Steve French <steve.french@primarydata.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.
The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.
Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.
========
OVERVIEW
========
The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.
A number of requests were gathered for features to be included. The
following have been included:
(1) Make the fields a consistent size on all arches and make them large.
(2) Spare space, request flags and information flags are provided for
future expansion.
(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).
(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).
This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].
(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).
(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).
And the following have been left out for future extension:
(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].
Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.
(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).
(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].
(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].
(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).
(10) Extra coherency data may be useful in making backups [Andreas Dilger].
(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).
(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...
(This requires a separate system call - I have an fsinfo() call idea
for this).
(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].
(Deferred to fsinfo).
(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].
(Deferred to fsinfo).
(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).
(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).
(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].
(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).
(16) Femtosecond-resolution timestamps [Dave Chinner].
(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).
(17) A set multiple attributes syscall to go with this.
===============
NEW SYSTEM CALL
===============
The new system call is:
int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);
The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.
Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):
(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.
(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.
(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.
mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.
buffer points to the destination for the data. This must be 256 bytes in
size.
======================
MAIN ATTRIBUTES RECORD
======================
The following structures are defined in which to return the main attribute
set:
struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};
struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};
The defined bits in request_mask and stx_mask are:
STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]
stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.
Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.
The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:
STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs
Within the kernel, the supported flags are listed by:
KSTAT_ATTR_FS_IOC_FLAGS
[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]
New flags include:
STATX_ATTR_AUTOMOUNT Object is an automount trigger
These are for the use of GUI tools that might want to mark files specially,
depending on what they are.
Fields in struct statx come in a number of classes:
(0) stx_dev_*, stx_blksize.
These are local system information and are always available.
(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.
These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.
If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.
If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.
Note that there are instances where the type might not be valid, for
instance Windows reparse points.
(2) stx_rdev_*.
This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.
(3) stx_btime.
Similar to (1), except this will be set to 0 if it doesn't exist.
=======
TESTING
=======
The following test program can be used to test the statx system call:
samples/statx/test-statx.c
Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.
Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.
[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
Secondly, the result of automounting on that directory.
[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull more btrfs updates from Chris Mason:
"Btrfs round two.
These are mostly a continuation of Dave Sterba's collection of
cleanups, but Filipe also has some bug fixes and performance
improvements"
* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (69 commits)
btrfs: add dummy callback for readpage_io_failed and drop checks
btrfs: drop checks for mandatory extent_io_ops callbacks
btrfs: document existence of extent_io ops callbacks
btrfs: let writepage_end_io_hook return void
btrfs: do proper error handling in btrfs_insert_xattr_item
btrfs: handle allocation error in update_dev_stat_item
btrfs: remove BUG_ON from __tree_mod_log_insert
btrfs: derive maximum output size in the compression implementation
btrfs: use predefined limits for calculating maximum number of pages for compression
btrfs: export compression buffer limits in a header
btrfs: merge nr_pages input and output parameter in compress_pages
btrfs: merge length input and output parameter in compress_pages
btrfs: constify name of subvolume in creation helpers
btrfs: constify buffers used by compression helpers
btrfs: constify input buffer of btrfs_csum_data
btrfs: constify device path passed to relevant helpers
btrfs: make btrfs_inode_resume_unlocked_dio take btrfs_inode
btrfs: make btrfs_inode_block_unlocked_dio take btrfs_inode
btrfs: Make btrfs_add_nondir take btrfs_inode
btrfs: Make btrfs_add_link take btrfs_inode
...
Pull vfs pile two from Al Viro:
- orangefs fix
- series of fs/namei.c cleanups from me
- VFS stuff coming from overlayfs tree
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
orangefs: Use RCU for destroy_inode
vfs: use helper for calling f_op->fsync()
mm: use helper for calling f_op->mmap()
vfs: use helpers for calling f_op->{read,write}_iter()
vfs: pass type instead of fn to do_{loop,iter}_readv_writev()
vfs: extract common parts of {compat_,}do_readv_writev()
vfs: wrap write f_ops with file_{start,end}_write()
vfs: deny copy_file_range() for non regular files
vfs: deny fallocate() on directory
vfs: create vfs helper vfs_tmpfile()
namei.c: split unlazy_walk()
namei.c: fold the check for DCACHE_OP_REVALIDATE into d_revalidate()
lookup_fast(): clean up the logics around the fallback to non-rcu mode
namei: fold unlazy_link() into its sole caller
Pull vfs sendmsg updates from Al Viro:
"More sendmsg work.
This is a fairly separate isolated stuff (there's a continuation
around lustre, but that one was too late to soak in -next), thus the
separate pull request"
* 'work.sendmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ncpfs: switch to sock_sendmsg()
ncpfs: don't mess with manually advancing iovec on send
ncpfs: sendmsg does *not* bugger iovec these days
ceph_tcp_sendpage(): use ITER_BVEC sendmsg
afs_send_pages(): use ITER_BVEC
rds: remove dead code
ceph: switch to sock_recvmsg()
usbip_recv(): switch to sock_recvmsg()
iscsi_target: deal with short writes on the tx side
[nbd] pass iov_iter to nbd_xmit()
[nbd] switch sock_xmit() to sock_{send,recv}msg()
[drbd] use sock_sendmsg()
in SMB2+ the get_dfs_refer operation uses a FSCTL. The request can be
made on any Tree Connection according to the specs. Since Samba only
accepted it on an IPC connection until recently, try that first.
https://lists.samba.org/archive/samba-technical/2017-February/118859.html
3.2.4.20.3 Application Requests DFS Referral Information:
> The client MUST search for an existing Session and TreeConnect to any
> share on the server identified by ServerName for the user identified by
> UserCredentials. If no Session and TreeConnect are found, the client
> MUST establish a new Session and TreeConnect to IPC$ on the target
> server as described in section 3.2.4.2 using the supplied ServerName and
> UserCredentials.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
When connected to a DFS capable share, the client must set the
SMB2_FLAGS_DFS_OPERATIONS flag in the SMB2 header and use
DFS path names: "<server>\<share>\<path>" *without* leading \\.
Sources:
[MS-SMB2] 3.2.5.5 Receiving an SMB2 TREE_CONNECT Response
> TreeConnect.IsDfsShare MUST be set to TRUE, if the SMB2_SHARE_CAP_DFS
> bit is set in the Capabilities field of the response.
[MS-SMB2] 3.2.4.3 Application Requests Opening a File
> If TreeConnect.IsDfsShare is TRUE, the SMB2_FLAGS_DFS_OPERATIONS flag
> is set in the Flags field.
[MS-SMB2] 2.2.13 SMB2 CREATE Request, NameOffset:
> If SMB2_FLAGS_DFS_OPERATIONS is set in the Flags field of the SMB2
> header, the file name includes a prefix that will be processed during
> DFS name normalization as specified in section 3.3.5.9. Otherwise, the
> file name is relative to the share that is identified by the TreeId in
> the SMB2 header.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Pull security subsystem fixes from James Morris:
"Two fixes for the security subsystem:
- keys: split both rcu_dereference_key() and user_key_payload() into
versions which can be called with or without holding the key
semaphore.
- SELinux: fix Android init(8) breakage due to new cgroup security
labeling support when using older policy"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
selinux: wrap cgroup seclabel support with its own policy capability
KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload()
So far we initialized bd_bdi only in bdget(). That is fine for normal
bdev inodes however for the special case of the root inode of
blockdev_superblock that function is never called and thus bd_bdi is
left uninitialized. As a result bdev_evict_inode() may oops doing
bdi_put(root->bd_bdi) on that inode as can be seen when doing:
mount -t bdev none /mnt
Fix the problem by initializing bd_bdi when first allocating the inode
and then reinitializing bd_bdi in bdev_evict_inode().
Thanks to syzkaller team for finding the problem.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: b1d2dc5659 ("block: Make blk_get_backing_dev_info() safe without open bdev")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
