Build AM43x power domain, clock domain and hwmod data.

Many of AM43x IP's and interconnects are similar as that in AM335x,
hence AM335x hwmod data is being reused with necessary changes.

Earlier the plan was to reuse AM335x specific PRCM code, but as AM43x
PRCM register layout is much similar to OMAP4/5, AM335x PRCM is
divorced and instead married with OMAP4/5 PRCM for AM43x.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Reuse OMAP4 operations on AM43x.

Context related ops are not used on AM43x, as this would not add value
when using DT and AM43x is DT only boot. This additionally helps not to
add context register offset for each hwmod.
Signed-off-by: NAmbresh K <ambresh@ti.com>
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add hwmod support for IP's that are present in AM43x, but not in AM335x.
AM43x additional ones added here are,
1. synctimer
2. timer8-11
3. ehrpwm3-5
4. spi2-4
5. gpio4-5

AM43x pruss interconnect which is different as compared to AM335x, has
been taken care.

And register offsets for same hwmod's shared with AM335x is different,
AM43x register offsets are updated appropriately.

ocp clock of those in l4_wkup is fed from "sys_clkin_ck" instead of
"dpll_core_m4_div2_ck", so "ocpif" for those in AM43x l4_wkup has been
added seperately.

hwmod's has been added for those that have main clock (wkup_m3, control,
gpio0) and clock domain (l4_hs) different from AM335x. debugss and
adc_tsc that have different clocks and clockdomains repectively has not
been added due to the reasons mentioned below.

AM43x also has IP's like qspi, hdq1w, vpfe, des, rng, usb, dss, debugss,
adc_tsc. These are not handled here due to both/either of following
reasons,
1. To avoid churn; most of them don't have DT bindings, which would
   necessitate adding address space in hwmod, which any way would have
   to be removed once DT bindings happen with driver support.
2. patches would come in from sources other than the author
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add the data file to describe clock domains in AM43x SoC.
OMAP4 clockdomain operations is being reused here.
Signed-off-by: NAmbresh K <ambresh@ti.com>
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add the data file to describe all power domains in AM43x SoC.
OMAP4 powerdomain operations is being reused here.
Signed-off-by: NAmbresh K <ambresh@ti.com>
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add AM43x CMINST, CDOFFS, RM_RSTST & RM_RSTCTRL definitions - minimal
ones that would be used.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Hwmod common to AM43x and AM335x has register offsets different. It is
now updated based on SoC detection at run time, hence remove statically
initialized ones.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Most of IP's in AM335x is present on AM43x and so in those cases both
will use same hwmod database (except for a few cases where clock related
details differ), but there is difference w.r.t register offset between
these. Update register offsets at runtime based on the SoC detected to
help in sharing otherwise same hwmod.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

AM335x and AM43x have most of the IP's and interconnect's similar.
Instead of adding redundant hwmod data, move interconnects and hwmod
similar between AM335x and AM43x to a common location. This helps in
reuse on AM43x.

AM335x interconnects that has difference and not present in AM43x are
not moved. ocp clock of those in l4_wkup is fed from a different source
for AM43x. Also pruss interconnect is different.

AM335x hwmod's that has difference other than prcm register offsets
(difference is in clocks of wkup_m3, control, gpio0, debugss and clock
domain of l4_hs, adc_tsc as compared to AM43x) and those that are not
present in AM43x are not moved.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Most of the AM43x CM reg address offsets are with MSB bit '1' (on
16-bit value) leading to arithmetic miscalculations while calculating
CLOCK ENABLE register's address because cm_inst field was a type of
"const s16", so make it "const u16".

Also modify relevant functions so as to take care of the above.

[afzal@ti.com: fixup and cleanup]
Signed-off-by: NAnkur Kishore <a-kishore@ti.com>
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add RNG hwmod data for AM33xx SoC.
Signed-off-by: NLokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Now that we have DT bindings to specify which devices should not
be reset and idled during init, make hwmod extract the information
(and store them in internal flags) from Device tree.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
[paul@pwsan.com: updated to apply]
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

For modules/IPs/hwmods which do not have
-1- sys->class->reset()
and
-2- hardreset lines
and
-3- No way to do an ocp reset (no sysc control)
the flag 'HWMOD_INIT_NO_RESET' is not much useful.

Cleanup all such instances across various hwmod data files.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add the missing sysc configuration to the AM335 spinlock hwmod
data. This ensures that smart-idle is enabled whenever the module
is enabled by the driver.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add the hwmod data for the spinlock IP in OMAP5 SoC.
This is needed to be able to enable the OMAP spinlock
support for OMAP5.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Add hwmod data for High Speed USB host and TLL modules

CC: Paul Walmsley <paul@pwsan.com>
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

This patch adds Synchronous Serial Interface (SSI) hwmod support for
OMAP34xx SoCs.
Signed-off-by: NSebastian Reichel <sre@debian.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

The hwmod init sequence involves initializing and idling all the
hwmods during bootup. If a module class has sysconfig, the init
sequence utilizes the module register base for performing any
sysc configuration.

The module address space is being removed from hwmod database and
retrieved from the <reg> property of the corresponding DT node.
If a hwmod does not have its corresponding DT node defined and the
memory address space is not defined in the corresponding
omap_hwmod_ocp_if, then the module register target address space
would be NULL and any sysc programming would result in a NULL
pointer dereference and a kernel boot hang.

Handle this scenario by checking for a valid module address space
during the _init of each hwmod, and leaving it in the registered
state if no module register address base is defined in either of
the hwmod data or the DT data.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NNishanth Menon <nm@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
[paul@pwsan.com: use -ENXIO rather than -ENOMEM to indicate a missing address
 space error; fixed checkpatch.pl problem]
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

Modify the code to use current_euid(), and in_egroup_p, as in done
in fs/proc/proc_sysctl.c:test_perm()

Cc: stable@vger.kernel.org
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reported-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull SCSI target fixes from Nicholas Bellinger:
 "Here are the outstanding target fixes queued up for v3.12-rc4 code.

  The highlights include:

   - Make vhost/scsi tag percpu_ida_alloc() use GFP_ATOMIC
   - Allow sess_cmd_map allocation failure fallback to use vzalloc
   - Fix COMPARE_AND_WRITE se_cmd->data_length bug with FILEIO backends
   - Fixes for COMPARE_AND_WRITE callback recursive failure OOPs + non
     zero scsi_status bug
   - Make iscsi-target do acknowledgement tag release from RX context
   - Setup iscsi-target with extra (cmdsn_depth / 2) percpu_ida tags

  Also included is a iscsi-target patch CC'ed for v3.10+ that avoids
  legacy wait_for_task=true release during fast-past StatSN
  acknowledgement, and two other SRP target related patches that address
  long-standing issues that are CC'ed for v3.3+.

  Extra thanks to Thomas Glanzmann for his testing feedback with
  COMPARE_AND_WRITE + EXTENDED_COPY VAAI logic"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iscsi-target; Allow an extra tag_num / 2 number of percpu_ida tags
  iscsi-target: Perform release of acknowledged tags from RX context
  iscsi-target: Only perform wait_for_tasks when performing shutdown
  target: Fail on non zero scsi_status in compare_and_write_callback
  target: Fix recursive COMPARE_AND_WRITE callback failure
  target: Reset data_length for COMPARE_AND_WRITE to NoLB * block_size
  ib_srpt: always set response for task management
  target: Fall back to vzalloc upon ->sess_cmd_map kzalloc failure
  vhost/scsi: Use GFP_ATOMIC with percpu_ida_alloc for obtaining tag
  ib_srpt: Destroy cm_id before destroying QP.
  target: Fix xop->dbl assignment in target_xcopy_parse_segdesc_02

Pull slave-dmaengine fixes from Vinod Koul:
 "Here is the slave dmanegine fixes.  We have the fix for deadlock issue
  on imx-dma by Michael and Josh's edma config fix along with author
  change"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: imx-dma: fix callback path in tasklet
  dmaengine: imx-dma: fix lockdep issue between irqhandler and tasklet
  dmaengine: imx-dma: fix slow path issue in prep_dma_cyclic
  dma/Kconfig: Make TI_EDMA select TI_PRIV_EDMA
  edma: Update author email address

Pull btrfs fixes from Chris Mason:
 "This is a small collection of fixes, including a regression fix from
  Liu Bo that solves rare crashes with compression on.

  I've merged my for-linus up to 3.12-rc3 because the top commit is only
  meant for 3.12.  The rest of the fixes are also available in my master
  branch on top of my last 3.11 based pull"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: Fix crash due to not allocating integrity data for a bioset
  Btrfs: fix a use-after-free bug in btrfs_dev_replace_finishing
  Btrfs: eliminate races in worker stopping code
  Btrfs: fix crash of compressed writes
  Btrfs: fix transid verify errors when recovering log tree

Pull GPIO fixes from Linus Walleij:
 "Two patches for the OMAP driver, dealing with setting up IRQs properly
  on the device tree boot path"

* tag 'gpio-v3.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio/omap: auto-setup a GPIO when used as an IRQ
  gpio/omap: maintain GPIO and IRQ usage separately

Pull USB fixes from Greg KH:
 "Here are none fixes for various USB driver problems.  The majority are
  gadget/musb fixes, but there are some new device ids in here as well"

* tag 'usb-3.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: chipidea: add Intel Clovertrail pci id
  usb: gadget: s3c-hsotg: fix can_write limit for non-periodic endpoints
  usb: gadget: f_fs: fix error handling
  usb: musb: dsps: do not bind to "musb-hdrc"
  USB: serial: option: Ignore card reader interface on Huawei E1750
  usb: musb: gadget: fix otg active status flag
  usb: phy: gpio-vbus: fix deferred probe from __init
  usb: gadget: pxa25x_udc: fix deferred probe from __init
  usb: musb: fix otg default state

Pull tty fixes from Greg KH:
 "Here are two tty driver fixes for 3.12-rc4.

  One fixes the reported regression in the n_tty code that a number of
  people found recently, and the other one fixes an issue with xen
  consoles that broke in 3.10"

* tag 'tty-3.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  xen/hvc: allow xenboot console to be used again
  tty: Fix pty master read() after slave closes

Pull staging fixes from Greg KH:
 "Here are 4 tiny staging and iio driver fixes for 3.12-rc4.  Nothing
  major, just some small fixes for reported issues"

* tag 'staging-3.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: comedi: ni_65xx: (bug fix) confine insn_bits to one subdevice
  iio:magnetometer: Bugfix magnetometer default output registers
  iio: Remove debugfs entries in iio_device_unregister()
  iio: amplifiers: ad8366: Remove regulator_put

When btrfs creates a bioset, we must also allocate the integrity data pool.
Otherwise btrfs will crash when it tries to submit a bio to a checksumming
disk:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
 IP: [<ffffffff8111e28a>] mempool_alloc+0x4a/0x150
 PGD 2305e4067 PUD 23063d067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP
 Modules linked in: btrfs scsi_debug xfs ext4 jbd2 ext3 jbd mbcache
sch_fq_codel eeprom lpc_ich mfd_core nfsd exportfs auth_rpcgss af_packet
raid6_pq xor zlib_deflate libcrc32c [last unloaded: scsi_debug]
 CPU: 1 PID: 4486 Comm: mount Not tainted 3.12.0-rc1-mcsum #2
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
 task: ffff8802451c9720 ti: ffff880230698000 task.ti: ffff880230698000
 RIP: 0010:[<ffffffff8111e28a>]  [<ffffffff8111e28a>] mempool_alloc+0x4a/0x150
 RSP: 0018:ffff880230699688  EFLAGS: 00010286
 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000005f8445
 RDX: 0000000000000001 RSI: 0000000000000010 RDI: 0000000000000000
 RBP: ffff8802306996f8 R08: 0000000000011200 R09: 0000000000000008
 R10: 0000000000000020 R11: ffff88009d6e8000 R12: 0000000000011210
 R13: 0000000000000030 R14: ffff8802306996b8 R15: ffff8802451c9720
 FS:  00007f25b8a16800(0000) GS:ffff88024fc80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000018 CR3: 0000000230576000 CR4: 00000000000007e0
 Stack:
  ffff8802451c9720 0000000000000002 ffffffff81a97100 0000000000281250
  ffffffff81a96480 ffff88024fc99150 ffff880228d18200 0000000000000000
  0000000000000000 0000000000000040 ffff880230e8c2e8 ffff8802459dc900
 Call Trace:
  [<ffffffff811b2208>] bio_integrity_alloc+0x48/0x1b0
  [<ffffffff811b26fc>] bio_integrity_prep+0xac/0x360
  [<ffffffff8111e298>] ? mempool_alloc+0x58/0x150
  [<ffffffffa03e8041>] ? alloc_extent_state+0x31/0x110 [btrfs]
  [<ffffffff81241579>] blk_queue_bio+0x1c9/0x460
  [<ffffffff8123e58a>] generic_make_request+0xca/0x100
  [<ffffffff8123e639>] submit_bio+0x79/0x160
  [<ffffffffa03f865e>] btrfs_map_bio+0x48e/0x5b0 [btrfs]
  [<ffffffffa03c821a>] btree_submit_bio_hook+0xda/0x110 [btrfs]
  [<ffffffffa03e7eba>] submit_one_bio+0x6a/0xa0 [btrfs]
  [<ffffffffa03ef450>] read_extent_buffer_pages+0x250/0x310 [btrfs]
  [<ffffffff8125eef6>] ? __radix_tree_preload+0x66/0xf0
  [<ffffffff8125f1c5>] ? radix_tree_insert+0x95/0x260
  [<ffffffffa03c66f6>] btree_read_extent_buffer_pages.constprop.128+0xb6/0x120
[btrfs]
  [<ffffffffa03c8c1a>] read_tree_block+0x3a/0x60 [btrfs]
  [<ffffffffa03caefd>] open_ctree+0x139d/0x2030 [btrfs]
  [<ffffffffa03a282a>] btrfs_mount+0x53a/0x7d0 [btrfs]
  [<ffffffff8113ab0b>] ? pcpu_alloc+0x8eb/0x9f0
  [<ffffffff81167305>] ? __kmalloc_track_caller+0x35/0x1e0
  [<ffffffff81176ba0>] mount_fs+0x20/0xd0
  [<ffffffff81191096>] vfs_kern_mount+0x76/0x120
  [<ffffffff81193320>] do_mount+0x200/0xa40
  [<ffffffff81135cdb>] ? strndup_user+0x5b/0x80
  [<ffffffff81193bf0>] SyS_mount+0x90/0xe0
  [<ffffffff8156d31d>] system_call_fastpath+0x1a/0x1f
 Code: 4c 8d 75 a8 4c 89 6d e8 45 89 e0 4c 8d 6f 30 48 89 5d d8 41 83 e0 af 48
89 fb 49 83 c6 18 4c 89 7d f8 65 4c 8b 3c 25 c0 b8 00 00 <48> 8b 73 18 44 89 c7
44 89 45 98 ff 53 20 48 85 c0 48 89 c2 74
 RIP  [<ffffffff8111e28a>] mempool_alloc+0x4a/0x150
  RSP <ffff880230699688>
 CR2: 0000000000000018
 ---[ end trace 7a96042017ed21e2 ]---
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Pull CIFS fixes from Steve French:
 "Small set of cifs fixes.  Most important is Jeff's fix that works
  around disconnection problems which can be caused by simultaneous use
  of user space tools (starting a long running smbclient backup then
  doing a cifs kernel mount) or multiple cifs mounts through a NAT, and
  Jim's fix to deal with reexport of cifs share.

  I expect to send two more cifs fixes next week (being tested now) -
  fixes to address an SMB2 unmount hang when server dies and a fix for
  cifs symlink handling of Windows "NFS" symlinks"

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  [CIFS] update cifs.ko version
  [CIFS] Remove ext2 flags that have been moved to fs.h
  [CIFS] Provide sane values for nlink
  cifs: stop trying to use virtual circuits
  CIFS: FS-Cache: Uncache unread pages in cifs_readpages() before freeing them

Pull PCI fix from Bjorn Helgaas:
 "We merged what was intended to be an MMCONFIG cleanup, but in fact,
  for systems without _CBA (which is almost everything), it broke
  extended config space for domain 0 and it broke all config space for
  other domains.

  This reverts the change"

* tag 'pci-v3.12-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  Revert "x86/PCI: MMCONFIG: Check earlier for MMCONFIG region at address zero"

This reverts commit 07f9b61c.

07f9b61c was intended to be a cleanup that didn't change anything, but in
fact, for systems without _CBA (which is almost everything), it broke
extended config space for domain 0 and all config space for other domains.

Reference: http://lkml.kernel.org/r/20131004011806.GE20450@dangermouse.emea.sgi.comReported-by: NHedi Berriche <hedi@sgi.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Pull ACPI and power management fixes from Rafael Wysocki:

 - The resume part of user space driven hibernation (s2disk) is now
   broken after the change that moved the creation of memory bitmaps to
   after the freezing of tasks, because I forgot that the resume utility
   loaded the image before freezing tasks and needed the bitmaps for
   that.  The fix adds special handling for that case.

 - One of recent commits changed the export of acpi_bus_get_device() to
   EXPORT_SYMBOL_GPL(), which was technically correct but broke existing
   binary modules using that function including one in particularly
   widespread use.  Change it back to EXPORT_SYMBOL().

 - The intel_pstate driver sometimes fails to disable turbo if its
   no_turbo sysfs attribute is set.  Fix from Srinivas Pandruvada.

 - One of recent cpufreq fixes forgot to update a check in cpufreq-cpu0
   which still (incorrectly) treats non-NULL as non-error.  Fix from
   Philipp Zabel.

 - The SPEAr cpufreq driver uses a wrong variable type in one place
   preventing it from catching errors returned by one of the functions
   called by it.  Fix from Sachin Kamat.

* tag 'pm+acpi-3.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: Use EXPORT_SYMBOL() for acpi_bus_get_device()
  intel_pstate: fix no_turbo
  cpufreq: cpufreq-cpu0: NULL is a valid regulator, part 2
  cpufreq: SPEAr: Fix incorrect variable type
  PM / hibernate: Fix user space driven resume regression

Pull xfs bugfixes from Ben Myers:
 "There are lockdep annotations for project quotas, a fix for dirent
  dtype support on v4 filesystems, a fix for a memory leak in recovery,
  and a fix for the build error that resulted from it.  D'oh"

* tag 'xfs-for-linus-v3.12-rc4' of git://oss.sgi.com/xfs/xfs:
  xfs: Use kmem_free() instead of free()
  xfs: fix memory leak in xlog_recover_add_to_trans
  xfs: dirent dtype presence is dependent on directory magic numbers
  xfs: lockdep needs to know about 3 dquot-deep nesting

Now avc_audit() has no more users with that parameter. Remove it.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

.. so get rid of it.  The only indirect users were all the
avc_has_perm() callers which just expanded to have a zero flags
argument.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

free_device rcu callback, scheduled from btrfs_rm_dev_replace_srcdev,
can be processed before btrfs_scratch_superblock is called, which would
result in a use-after-free on btrfs_device contents.  Fix this by
zeroing the superblock before the rcu callback is registered.

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The current implementation of worker threads in Btrfs has races in
worker stopping code, which cause all kinds of panics and lockups when
running btrfs/011 xfstest in a loop.  The problem is that
btrfs_stop_workers is unsynchronized with respect to check_idle_worker,
check_busy_worker and __btrfs_start_workers.

E.g., check_idle_worker race flow:

       btrfs_stop_workers():            check_idle_worker(aworker):
- grabs the lock
- splices the idle list into the
  working list
- removes the first worker from the
  working list
- releases the lock to wait for
  its kthread's completion
                                  - grabs the lock
                                  - if aworker is on the working list,
                                    moves aworker from the working list
                                    to the idle list
                                  - releases the lock
- grabs the lock
- puts the worker
- removes the second worker from the
  working list
                              ......
        btrfs_stop_workers returns, aworker is on the idle list
                 FS is umounted, memory is freed
                              ......
              aworker is waken up, fireworks ensue

With this applied, I wasn't able to trigger the problem in 48 hours,
whereas previously I could reliably reproduce at least one of these
races within an hour.
Reported-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The crash[1] is found by xfstests/generic/208 with "-o compress",
it's not reproduced everytime, but it does panic.

The bug is quite interesting, it's actually introduced by a recent commit
(573aecaf,
Btrfs: actually limit the size of delalloc range).

Btrfs implements delay allocation, so during writeback, we
(1) get a page A and lock it
(2) search the state tree for delalloc bytes and lock all pages within the range
(3) process the delalloc range, including find disk space and create
    ordered extent and so on.
(4) submit the page A.

It runs well in normal cases, but if we're in a racy case, eg.
buffered compressed writes and aio-dio writes,
sometimes we may fail to lock all pages in the 'delalloc' range,
in which case, we need to fall back to search the state tree again with
a smaller range limit(max_bytes = PAGE_CACHE_SIZE - offset).

The mentioned commit has a side effect, that is, in the fallback case,
we can find delalloc bytes before the index of the page we already have locked,
so we're in the case of (delalloc_end <= *start) and return with (found > 0).

This ends with not locking delalloc pages but making ->writepage still
process them, and the crash happens.

This fixes it by just thinking that we find nothing and returning to caller
as the caller knows how to deal with it properly.

[1]:
------------[ cut here ]------------
kernel BUG at mm/page-writeback.c:2170!
[...]
CPU: 2 PID: 11755 Comm: btrfs-delalloc- Tainted: G           O 3.11.0+ #8
[...]
RIP: 0010:[<ffffffff810f5093>]  [<ffffffff810f5093>] clear_page_dirty_for_io+0x1e/0x83
[...]
[ 4934.248731] Stack:
[ 4934.248731]  ffff8801477e5dc8 ffffea00049b9f00 ffff8801869f9ce8 ffffffffa02b841a
[ 4934.248731]  0000000000000000 0000000000000000 0000000000000fff 0000000000000620
[ 4934.248731]  ffff88018db59c78 ffffea0005da8d40 ffffffffa02ff860 00000001810016c0
[ 4934.248731] Call Trace:
[ 4934.248731]  [<ffffffffa02b841a>] extent_range_clear_dirty_for_io+0xcf/0xf5 [btrfs]
[ 4934.248731]  [<ffffffffa02a8889>] compress_file_range+0x1dc/0x4cb [btrfs]
[ 4934.248731]  [<ffffffff8104f7af>] ? detach_if_pending+0x22/0x4b
[ 4934.248731]  [<ffffffffa02a8bad>] async_cow_start+0x35/0x53 [btrfs]
[ 4934.248731]  [<ffffffffa02c694b>] worker_loop+0x14b/0x48c [btrfs]
[ 4934.248731]  [<ffffffffa02c6800>] ? btrfs_queue_worker+0x25c/0x25c [btrfs]
[ 4934.248731]  [<ffffffff810608f5>] kthread+0x8d/0x95
[ 4934.248731]  [<ffffffff81060868>] ? kthread_freezable_should_stop+0x43/0x43
[ 4934.248731]  [<ffffffff814fe09c>] ret_from_fork+0x7c/0xb0
[ 4934.248731]  [<ffffffff81060868>] ? kthread_freezable_should_stop+0x43/0x43
[ 4934.248731] Code: ff 85 c0 0f 94 c0 0f b6 c0 59 5b 5d c3 0f 1f 44 00 00 55 48 89 e5 41 54 53 48 89 fb e8 2c de 00 00 49 89 c4 48 8b 03 a8 01 75 02 <0f> 0b 4d 85 e4 74 52 49 8b 84 24 80 00 00 00 f6 40 20 01 75 44
[ 4934.248731] RIP  [<ffffffff810f5093>] clear_page_dirty_for_io+0x1e/0x83
[ 4934.248731]  RSP <ffff8801869f9c48>
[ 4934.280307] ---[ end trace 36f06d3f8750236a ]---
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

If we crash with a log, remount and recover that log, and then crash before we
can commit another transaction we will get transid verify errors on the next
mount.  This is because we were not zero'ing out the log when we committed the
transaction after recovery.  This is ok as long as we commit another transaction
at some point in the future, but if you abort or something else goes wrong you
can end up in this weird state because the recovery stuff says that the tree log
should have a generation+1 of the super generation, which won't be the case of
the transaction that was started for recovery.  Fix this by removing the check
and _always_ zero out the log portion of the super when we commit a transaction.
This fixes the transid verify issues I was seeing with my force errors tests.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>