eCryptfs: Avoid unnecessary disk read and data decryption during writing

ecryptfs_write_begin grabs a page from page cache for writing.
If the page contains invalid data, or data older than the
counterpart on the disk, eCryptfs will read out the
corresponing data from the disk into the page, decrypt them,
then perform writing. However, for this page, if the length
of the data to be written into is equal to page size,
that means the whole page of data will be overwritten,
in which case, it does not matter whatever the data were before,
it is beneficial to perform writing directly rather than bothering
to read and decrypt first.

With this optimization, according to our test on a machine with
Intel Core 2 Duo processor, iozone 'write' operation on an existing
file with write size being multiple of page size will enjoy a steady
3x speedup.

Signed-off-by: Li Wang <wangli@kylinos.com.cn>
Signed-off-by: Yunchuan Wen <wenyunchuan@kylinos.com.cn>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
ext4: fix extent tree corruption caused by hole punch

When depth of extent tree is greater than 1, logical start value of
interior node is not correctly updated in ext4_ext_rm_idx.

Signed-off-by: Forrest Liu <forrestl@synology.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Ashish Sangwan <ashishsangwan2@gmail.com>
Cc: stable@vger.kernel.org
eCryptfs: fix to use list_for_each_entry_safe() when delete items

Since we will be removing items off the list using list_del() we need
to use a safer version of the list_for_each_entry() macro aptly named
list_for_each_entry_safe(). We should use the safe macro if the loop
involves deletions of items.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
[tyhicks: Fixed compiler err - missing list_for_each_entry_safe() param]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
fs/ecryptfs/crypto.c: make ecryptfs_encode_for_filename() static

the function ecryptfs_encode_for_filename() is only used in this file

Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
ext4: check dioread_nolock on remount

Currently we allow enabling dioread_nolock mount option on remount for
filesystems where blocksize < PAGE_CACHE_SIZE.  This isn't really
supported so fix the bug by moving the check for blocksize !=
PAGE_CACHE_SIZE into parse_options(). Change the original PAGE_SIZE to
PAGE_CACHE_SIZE along the way because that's what we are really
interested in.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Cc: stable@vger.kernel.org
jbd2: fix assertion failure in jbd2_journal_flush()

The following race is possible between start_this_handle() and someone
calling jbd2_journal_flush().

Process A                              Process B
start_this_handle().
  if (journal->j_barrier_count) # false
  if (!journal->j_running_transaction) { #true
    read_unlock(&journal->j_state_lock);
                                       jbd2_journal_lock_updates()
                                       jbd2_journal_flush()
                                         write_lock(&journal->j_state_lock);
                                         if (journal->j_running_transaction) {
                                           # false
                                         ... wait for committing trans ...
                                         write_unlock(&journal->j_state_lock);
    ...
    write_lock(&journal->j_state_lock);
    if (!journal->j_running_transaction) { # true
      jbd2_get_transaction(journal, new_transaction);
    write_unlock(&journal->j_state_lock);
    goto repeat; # eventually blocks on j_barrier_count > 0
                                         ...
                                         J_ASSERT(!journal->j_running_transaction);
                                           # fails

We fix the race by rechecking j_barrier_count after reacquiring j_state_lock
in exclusive mode.

Reported-by: yjwsignal@empal.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
ext4: split off ext4_journalled_invalidatepage()

In data=journal mode we don't need delalloc or DIO handling in invalidatepage
and similarly in other modes we don't need the journal handling. So split
invalidatepage implementations.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: fix deadlock in journal_unmap_buffer()

We cannot wait for transaction commit in journal_unmap_buffer()
because we hold page lock which ranks below transaction start.  We
solve the issue by bailing out of journal_unmap_buffer() and
jbd2_journal_invalidatepage() with -EBUSY.  Caller is then responsible
for waiting for transaction commit to finish and try invalidation
again. Since the issue can happen only for page stradding i_size, it
is simple enough to manually call jbd2_journal_invalidatepage() for
such page from ext4_setattr(), check the return value and wait if
necessary.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: fix an incorrect comment about i_mutex

i_mutex is not held when ->sync_file is called.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: remove unaligned AIO warning printk

Although I put this in, I now think it was a bad decision.  For most
users, there is very little to be done in this case.  They get the
message, once per day, with no real context or proposed action.  TBH,
it generates support calls when it probably does not need to; the
message sounds more dire than the situation really is.

Just nuke it.  Normal investigation via blktrace or whatnot can
reveal poor IO patterns if bad performance is encountered.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: include journal blocks in df overhead calcs

To more accurately calculate overhead for "bsd" style
df reporting, we should count the journal blocks as
overhead as well.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Tested-by: Eric Whitney <enwlinux@gmail.com>
ext4: do not try to write superblock on ro remount w/o journal

When a journal-less ext4 filesystem is mounted on a read-only block
device (blockdev --setro will do), each remount (for other, unrelated,
flags, like suid=>nosuid etc) results in a series of scary messages
from kernel telling about I/O errors on the device.

This is becauese of the following code ext4_remount():

       if (sbi->s_journal == NULL)
                ext4_commit_super(sb, 1);

at the end of remount procedure, which forces writing (flushing) of
a superblock regardless whenever it is dirty or not, if the filesystem
is readonly or not, and whenever the device itself is readonly or not.

We only need call ext4_commit_super when the file system had been
previously mounted read/write.

Thanks to Eric Sandeen for help in diagnosing this issue.

Signed-off-By: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
PCI: Remove spurious error for sriov_numvfs store and simplify flow

If we request "num_vfs" and the driver's sriov_configure() method enables
exactly that number ("num_vfs_enabled"), we complain "Invalid value for
number of VFs to enable" and return an error.  We should silently return
success instead.

Also, use kstrtou16() since numVFs is defined to be a 16-bit field and
rework to simplify control flow.

Reported-by: Greg Rose <gregory.v.rose@intel.com>
Reference: http://lkml.kernel.org/r/20121214101911.00002f59@unknown
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Donald Dutile <ddutile@redhat.com>
PCI: Work around Stratus ftServer broken PCIe hierarchy (fix DMI check)

Commit 284f5f9 was intended to disable the "only_one_child()" optimization
on Stratus ftServer systems, but its DMI check is wrong.  It looks for
DMI_SYS_VENDOR that contains "ftServer", when it should look for
DMI_SYS_VENDOR containing "Stratus" and DMI_PRODUCT_NAME containing
"ftServer".

Tested on Stratus ftServer 6400.

Reported-by: Fadeeva Marina <astarta@rat.ru>
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=51331
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v3.5+
PCI: Add PCIe Link Capability link speed and width names

Add standard #defines for the Supported Link Speeds field in the PCIe
Link Capabilities register.

Note that prior to PCIe spec r3.0, these encodings were defined:

    0001b  2.5GT/s Link speed supported
    0010b  5.0GT/s and 2.5GT/s Link speed supported

Starting with spec r3.0, these encodings refer to bits 0 and 1 in the
Supported Link Speeds Vector in the Link Capabilities 2 register, and bits
0 and 1 there mean 2.5 GT/s and 5.0 GT/s, respectively.  Therefore, code
that followed r2.0 and interpreted 0x1 as 2.5GT/s and 0x2 as 5.0GT/s will
continue to work, and we can identify a device using the new encodings
because it will have a non-zero Link Capabilities 2 register.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/PM: Do not suspend port if any subordinate device needs PME polling

Ulrich reported that his USB3 cardreader does not work reliably when
connected to the USB3 port.  It turns out that USB3 controller failed to
awaken when plugging in the USB3 cardreader.  Further experiments found
that the USB3 host controller can only be awakened via polling, not via PME
interrupt.  But if the PCIe port to which the USB3 host controller is
connected is suspended, we cannot poll the controller because its config
space is not accessible when the PCIe port is in a low power state.

To solve the issue, the PCIe port will not be suspended if any subordinate
device needs PME polling.

[bhelgaas: use bool consistently rather than mixing int/bool]
Reference: http://lkml.kernel.org/r/50841CCC.9030809@uli-eckhardt.de
Reported-by: Ulrich Eckhardt <usb@uli-eckhardt.de>
Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: stable@vger.kernel.org	# v3.6+
PCI: Reduce Ricoh 0xe822 SD card reader base clock frequency to 50MHz

Otherwise it fails like this on cards like the Transcend 16GB SDHC card:

    mmc0: new SDHC card at address b368
    mmcblk0: mmc0:b368 SDC   15.0 GiB
    mmcblk0: error -110 sending status command, retrying
    mmcblk0: error -84 transferring data, sector 0, nr 8, cmd response 0x900, card status 0xb0

Tested on my Lenovo x200 laptop.

[bhelgaas: changelog]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Chris Ball <cjb@laptop.org>
CC: Manoj Iyer <manoj.iyer@canonical.com>
CC: stable@vger.kernel.org
ext4: lock i_mutex when truncating orphan inodes

Commit c278531d39 added a warning when ext4_flush_unwritten_io() is
called without i_mutex being taken.  It had previously not been taken
during orphan cleanup since races weren't possible at that point in
the mount process, but as a result of this c278531d39, we will now see
a kernel WARN_ON in this case.  Take the i_mutex in
ext4_orphan_cleanup() to suppress this warning.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Cc: stable@vger.kernel.org
ext4: avoid hang when mounting non-journal filesystems with orphan list

When trying to mount a file system which does not contain a journal,
but which does have a orphan list containing an inode which needs to
be truncated, the mount call with hang forever in
ext4_orphan_cleanup() because ext4_orphan_del() will return
immediately without removing the inode from the orphan list, leading
to an uninterruptible loop in kernel code which will busy out one of
the CPU's on the system.

This can be trivially reproduced by trying to mount the file system
found in tests/f_orphan_extents_inode/image.gz from the e2fsprogs
source tree.  If a malicious user were to put this on a USB stick, and
mount it on a Linux desktop which has automatic mounts enabled, this
could be considered a potential denial of service attack.  (Not a big
deal in practice, but professional paranoids worry about such things,
and have even been known to allocate CVE numbers for such problems.)

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Cc: stable@vger.kernel.org
libceph: move linger requests sooner in kick_requests()

The kick_requests() function is called by ceph_osdc_handle_map()
when an osd map change has been indicated.  Its purpose is to
re-queue any request whose target osd is different from what it
was when it was originally sent.

It is structured as two loops, one for incomplete but registered
requests, and a second for handling completed linger requests.
As a special case, in the first loop if a request marked to linger
has not yet completed, it is moved from the request list to the
linger list.  This is as a quick and dirty way to have the second
loop handle sending the request along with all the other linger
requests.

Because of the way it's done now, however, this quick and dirty
solution can result in these incomplete linger requests never
getting re-sent as desired.  The problem lies in the fact that
the second loop only arranges for a linger request to be sent
if it appears its target osd has changed.  This is the proper
handling for *completed* linger requests (it avoids issuing
the same linger request twice to the same osd).

But although the linger requests added to the list in the first loop
may have been sent, they have not yet completed, so they need to be
re-sent regardless of whether their target osd has changed.

The first required fix is we need to avoid calling __map_request()
on any incomplete linger request.  Otherwise the subsequent
__map_request() call in the second loop will find the target osd
has not changed and will therefore not re-send the request.

Second, we need to be sure that a sent but incomplete linger request
gets re-sent.  If the target osd is the same with the new osd map as
it was when the request was originally sent, this won't happen.
This can be fixed through careful handling when we move these
requests from the request list to the linger list, by unregistering
the request *before* it is registered as a linger request.  This
works because a side-effect of unregistering the request is to make
the request's r_osd pointer be NULL, and *that* will ensure the
second loop actually re-sends the linger request.

Processing of such a request is done at that point, so continue with
the next one once it's been moved.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>