The call to complete() in st_scsi_execute_end() wakes up sleeping thread
in write_behind_check(), which frees the st_request, thus invalidating
the pointer to the associated bio structure, which is then passed to the
blk_rq_unmap_user(). Fix by storing pointer to bio structure into
temporary local variable.

This bug is present since at least linux-2.6.32.

CC: stable@kernel.org
Signed-off-by: NPetr Uzel <petr.uzel@suse.cz>
Reported-by: NJuergen Groß <juergen.gross@ts.fujitsu.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Acked-by: NKai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Make sure that SCSI device removal via scsi_remove_host() does finish
all pending SCSI commands. Currently that's not the case and hence
removal of a SCSI host during I/O can cause a deadlock. See also
"blkdev_issue_discard() hangs forever if underlying storage device is
removed" (http://bugzilla.kernel.org/show_bug.cgi?id=40472). See also
http://lkml.org/lkml/2011/8/27/6.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Cc: <stable@kernel.org>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

There is no reason to limit the SCSI disk namespace to sdXXX.

Add new error messages to sd_probe() in the unlikely event that either
ida_get_new() or sd_format_disk_name() fail.
Signed-off-by: NDave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Bump driver vesion to 10.100.00.00
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The driver was setting the action to MPI2_CONFIG_ACTION_PAGE_READ_CURRENT,
which only returns active volumes. In order to get info on inactive volumes,
the driver needs to change the action to
MPI2_RAID_PGAD_FORM_GET_NEXT_CONFIGNUM, and traverse each config till the
iocstatus is MPI2_IOCSTATUS_CONFIG_INVALID_PAGE returned.
Added a change in the driver to remove the instance of
sas_device object when the driver returns "1" from the slave_configure callback.
Also fixed code to report the hot spares to the operating system with a /dev/sg
assigned.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

[SCSI] mpt2sas: Fix for issue Port Reset taking long time(around 5 mins) to complete while issued during creating a volume

This is due to the slave_configuration routine is getting called when
host reset is active, and config page reads are failing, and driver
attempts to added device with stale config data.

To fix the issue, added error checking in slave_configure to check
for configuration pages failing, and return "1" so the device  is
not configured.  The config pages are failing if raid volume is
configured while issuing a host reset, thus driver is reading stale
data and proceeding to attempt to add.  The fix is to return error
so the volume is not configured.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This is due to driver reporting a device missing to the OS then the OS sending
a SYNC_CACHE request to driver while the IO queues are locked due to host reset.

To fix the issue, the driver will be waking up the port enable context
immediately when the driver receives the reply message, instead of waiting
on the hot plug worker threads.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Fix for dead lock occurring between host_lock and sas_device_lock.

The deadlock is between two spin locks, between the shost->host_lock
and driver ioc->sas_device_lock.

The fix is to rearrange the code in the  FW/Driver device removal
handshake so the ioc->sas_device_lock is not occurring when the
shost->host_lock is taken.

[jejb: zero initialise sas_address to fix spurious compiler warning]
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

[SCSI] mpt2sas: Fix drives not getting properly deleted if sas cable is removed while host reset is active

The fix is in the driver-firmware handshake device removal code. We
need to read the controller ioc_state to see if controller is OPERATIONAL
prior to sending target reset and OP_REMOVE. Previously it was checking
the flag ioc->shost_recovery flag, which is always set when host reset is
active, thus preventing drives from getting properly deleted.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The fix is to inhibit the warning message in _scsih_get_sas_address
when the MPI2_IOCSTATUS_CONFIG_INVALID_PAGE ioc status is returned.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Fix for issue : While discovery is in progress, hot unplug and hot plug of
enclosure connected to the controller card is causing system to hang.

When a device is in the process of being detected at driver load time then
if it is removed, the device that is no longer present will not be added
to the list. So the code in _scsih_probe_sas() is rearranged as such so
the devices that failed to be detected are not added to the list.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

New feature Fast Load Support.

(1)Asynchronous SCSI scanning: This will allow the drivers to scan
for devices in parallel while other device drivers are loading at
the same time. This will improve the amount of time it takes for the
OS to load.

(2) Reporting Devices while port enable is active: This feature will
allow devices to be reported to OS immediately while port enable is
active. The previous implementation waits for port enable to complete,
and then report devices. This feature is only enabled on IT firmware
configurations when there are no boot device configured in BIOS Configuration
Utility, else the driver will wait till port enable completes reporting
devices. For IR firmware, this feature is turned off. This feature is to
address large SAS topologies (>100 drives) when the boot OS is using onboard
SATA device, in other words, the boot devices is not
connected to our controller.

(3) Scanning for devices after diagnostic reset completes: A new routine
_scsih_scan_start is added. This will scan the expander pages, IR pages,
and sas device pages, then reporting new devices to SCSI Mid layer. It
seems the driver is not supporting adding devices while diagnostic reset
is active. Apparently this is due to the sanity checks on
ioc->shost_recovery flag throughout the context of kernel work thread FIFO,
and the mpt2sas_fw_work.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

1)Added ProxyVF_ID field to Configuration Request message.
2)Added IO Unit Page 8, IO Unit Page 9,and IO Unit Page 10.
3)Added SASNotifyPrimitiveMasks field to IOC Page 7.
4)Added SAS NOTIFY Primitive event.
5)Added Temperature Threshold Event.
6)Added Host Message Event.
7)Added Send Host Message request and reply.
Signed-off-by: NNagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (204 commits)
  [SCSI] qla4xxx: export address/port of connection (fix udev disk names)
  [SCSI] ipr: Fix BUG on adapter dump timeout
  [SCSI] megaraid_sas: Fix instance access in megasas_reset_timer
  [SCSI] hpsa: change confusing message to be more clear
  [SCSI] iscsi class: fix vlan configuration
  [SCSI] qla4xxx: fix data alignment and use nl helpers
  [SCSI] iscsi class: fix link local mispelling
  [SCSI] iscsi class: Replace iscsi_get_next_target_id with IDA
  [SCSI] aacraid: use lower snprintf() limit
  [SCSI] lpfc 8.3.27: Change driver version to 8.3.27
  [SCSI] lpfc 8.3.27: T10 additions for SLI4
  [SCSI] lpfc 8.3.27: Fix queue allocation failure recovery
  [SCSI] lpfc 8.3.27: Change algorithm for getting physical port name
  [SCSI] lpfc 8.3.27: Changed worst case mailbox timeout
  [SCSI] lpfc 8.3.27: Miscellanous logic and interface fixes
  [SCSI] megaraid_sas: Changelog and version update
  [SCSI] megaraid_sas: Add driver workaround for PERC5/1068 kdump kernel panic
  [SCSI] megaraid_sas: Add multiple MSI-X vector/multiple reply queue support
  [SCSI] megaraid_sas: Add support for MegaRAID 9360/9380 12GB/s controllers
  [SCSI] megaraid_sas: Clear FUSION_IN_RESET before enabling interrupts
  ...

* 'for-linus' of git://ceph.newdream.net/git/ceph-client:
  libceph: fix double-free of page vector
  ceph: fix 32-bit ino numbers
  libceph: force resend of osd requests if we skip an osdmap
  ceph: use kernel DNS resolver
  ceph: fix ceph_monc_init memory leak
  ceph: let the set_layout ioctl set single traits
  Revert "ceph: don't truncate dirty pages in invalidate work thread"
  ceph: replace leading spaces with tabs
  libceph: warn on msg allocation failures
  libceph: don't complain on msgpool alloc failures
  libceph: always preallocate mon connection
  libceph: create messenger with client
  ceph: document ioctls
  ceph: implement (optional) max read size
  ceph: rename rsize -> rasize
  ceph: make readpages fully async

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (549 commits)
  ALSA: hda - Fix ADC input-amp handling for Cx20549 codec
  ALSA: hda - Keep EAPD turned on for old Conexant chips
  ALSA: hda/realtek - Fix missing volume controls with ALC260
  ASoC: wm8940: Properly set codec->dapm.bias_level
  ALSA: hda - Fix pin-config for ASUS W90V
  ALSA: hda - Fix surround/CLFE headphone and speaker pins order
  ALSA: hda - Fix typo
  ALSA: Update the sound git tree URL
  ALSA: HDA: Add new revision for ALC662
  ASoC: max98095: Convert codec->hw_write to snd_soc_write
  ASoC: keep pointer to resource so it can be freed
  ASoC: sgtl5000: Fix wrong mask in some snd_soc_update_bits calls
  ASoC: wm8996: Fix wrong mask for setting WM8996_AIF_CLOCKING_2
  ASoC: da7210: Add support for line out and DAC
  ASoC: da7210: Add support for DAPM
  ALSA: hda/realtek - Fix DAC assignments of multiple speakers
  ASoC: Use SGTL5000_LINREG_VDDD_MASK instead of hardcoded mask value
  ASoC: Set sgtl5000->ldo in ldo_regulator_register
  ASoC: wm8996: Use SND_SOC_DAPM_AIF_OUT for AIF2 Capture
  ASoC: wm8994: Use SND_SOC_DAPM_AIF_OUT for AIF3 Capture
  ...

* 'next-rebase' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci:
  PCI: Clean-up MPS debug output
  pci: Clamp pcie_set_readrq() when using "performance" settings
  PCI: enable MPS "performance" setting to properly handle bridge MPS
  PCI: Workaround for Intel MPS errata
  PCI: Add support for PASID capability
  PCI: Add implementation for PRI capability
  PCI: Export ATS functions to modules
  PCI: Move ATS implementation into own file
  PCI / PM: Remove unnecessary error variable from acpi_dev_run_wake()
  PCI hotplug: acpiphp: Prevent deadlock on PCI-to-PCI bridge remove
  PCI / PM: Extend PME polling to all PCI devices
  PCI quirk: mmc: Always check for lower base frequency quirk for Ricoh 1180:e823
  PCI: Make pci_setup_bridge() non-static for use by arch code
  x86: constify PCI raw ops structures
  PCI: Add quirk for known incorrect MPSS
  PCI: Add Solarflare vendor ID and SFC4000 device IDs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: (83 commits)
  mmc: fix compile error when CONFIG_BLOCK is not enabled
  mmc: core: Cleanup eMMC4.5 conditionals
  mmc: omap_hsmmc: if multiblock reads are broken, disable them
  mmc: core: add workaround for controllers with broken multiblock reads
  mmc: core: Prevent too long response times for suspend
  mmc: recognise SDIO cards with SDIO_CCCR_REV 3.00
  mmc: sd: Handle SD3.0 cards not supporting UHS-I bus speed mode
  mmc: core: support HPI send command
  mmc: core: Add cache control for eMMC4.5 device
  mmc: core: Modify the timeout value for writing power class
  mmc: core: new discard feature support at eMMC v4.5
  mmc: core: mmc sanitize feature support for v4.5
  mmc: dw_mmc: modify DATA register offset
  mmc: sdhci-pci: add flag for devices that can support runtime PM
  mmc: omap_hsmmc: ensure pbias configuration is always done
  mmc: core: Add Power Off Notify Feature eMMC 4.5
  mmc: sdhci-s3c: fix potential NULL dereference
  mmc: replace printk with appropriate display macro
  mmc: core: Add default timeout value for CMD6
  mmc: sdhci-pci: add runtime pm support
  ...

Merge branch 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm

* 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm: (178 commits)
  ARM: 7139/1: fix compilation with CONFIG_ARM_ATAG_DTB_COMPAT and large TEXT_OFFSET
  ARM: gic, local timers: use the request_percpu_irq() interface
  ARM: gic: consolidate PPI handling
  ARM: switch from NO_MACH_MEMORY_H to NEED_MACH_MEMORY_H
  ARM: mach-s5p64x0: remove mach/memory.h
  ARM: mach-s3c64xx: remove mach/memory.h
  ARM: plat-mxc: remove mach/memory.h
  ARM: mach-prima2: remove mach/memory.h
  ARM: mach-zynq: remove mach/memory.h
  ARM: mach-bcmring: remove mach/memory.h
  ARM: mach-davinci: remove mach/memory.h
  ARM: mach-pxa: remove mach/memory.h
  ARM: mach-ixp4xx: remove mach/memory.h
  ARM: mach-h720x: remove mach/memory.h
  ARM: mach-vt8500: remove mach/memory.h
  ARM: mach-s5pc100: remove mach/memory.h
  ARM: mach-tegra: remove mach/memory.h
  ARM: plat-tcc: remove mach/memory.h
  ARM: mach-mmp: remove mach/memory.h
  ARM: mach-cns3xxx: remove mach/memory.h
  ...

Fix up mostly pretty trivial conflicts in:
 - arch/arm/Kconfig
 - arch/arm/include/asm/localtimer.h
 - arch/arm/kernel/Makefile
 - arch/arm/mach-shmobile/board-ap4evb.c
 - arch/arm/mach-u300/core.c
 - arch/arm/mm/dma-mapping.c
 - arch/arm/mm/proc-v7.S
 - arch/arm/plat-omap/Kconfig
largely due to some CONFIG option renaming (ie CONFIG_PM_SLEEP ->
CONFIG_ARM_CPU_SUSPEND for the arm-specific suspend code etc) and
addition of NEED_MACH_MEMORY_H next to HAVE_IDE.

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs-queue: (21 commits)
  leases: fix write-open/read-lease race
  nfs: drop unnecessary locking in llseek
  ext4: replace cut'n'pasted llseek code with generic_file_llseek_size
  vfs: add generic_file_llseek_size
  vfs: do (nearly) lockless generic_file_llseek
  direct-io: merge direct_io_walker into __blockdev_direct_IO
  direct-io: inline the complete submission path
  direct-io: separate map_bh from dio
  direct-io: use a slab cache for struct dio
  direct-io: rearrange fields in dio/dio_submit to avoid holes
  direct-io: fix a wrong comment
  direct-io: separate fields only used in the submission path from struct dio
  vfs: fix spinning prevention in prune_icache_sb
  vfs: add a comment to inode_permission()
  vfs: pass all mask flags check_acl and posix_acl_permission
  vfs: add hex format for MAY_* flag values
  vfs: indicate that the permission functions take all the MAY_* flags
  compat: sync compat_stats with statfs.
  vfs: add "device" tag to /proc/self/mountstats
  cleanup: vfs: small comment fix for block_invalidatepage
  ...

Fix up trivial conflict in fs/gfs2/file.c (llseek changes)

* http://sucs.org/~rohan/git/gfs2-3.0-nmw: (24 commits)
  GFS2: Move readahead of metadata during deallocation into its own function
  GFS2: Remove two unused variables
  GFS2: Misc fixes
  GFS2: rewrite fallocate code to write blocks directly
  GFS2: speed up delete/unlink performance for large files
  GFS2: Fix off-by-one in gfs2_blk2rgrpd
  GFS2: Clean up ->page_mkwrite
  GFS2: Correctly set goal block after allocation
  GFS2: Fix AIL flush issue during fsync
  GFS2: Use cached rgrp in gfs2_rlist_add()
  GFS2: Call do_strip() directly from recursive_scan()
  GFS2: Remove obsolete assert
  GFS2: Cache the most recently used resource group in the inode
  GFS2: Make resource groups "append only" during life of fs
  GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme
  GFS2: Fix lseek after SEEK_DATA, SEEK_HOLE have been added
  GFS2: Clean up gfs2_create
  GFS2: Use ->dirty_inode()
  GFS2: Fix bug trap and journaled data fsync
  GFS2: Fix inode allocation error path
  ...

* '3.2-without-smb2' of git://git.samba.org/sfrench/cifs-2.6: (52 commits)
  Fix build break when freezer not configured
  Add definition for share encryption
  CIFS: Make cifs_push_locks send as many locks at once as possible
  CIFS: Send as many mandatory unlock ranges at once as possible
  CIFS: Implement caching mechanism for posix brlocks
  CIFS: Implement caching mechanism for mandatory brlocks
  CIFS: Fix DFS handling in cifs_get_file_info
  CIFS: Fix error handling in cifs_readv_complete
  [CIFS] Fixup trivial checkpatch warning
  [CIFS] Show nostrictsync and noperm mount options in /proc/mounts
  cifs, freezer: add wait_event_freezekillable and have cifs use it
  cifs: allow cifs_max_pending to be readable under /sys/module/cifs/parameters
  cifs: tune bdi.ra_pages in accordance with the rsize
  cifs: allow for larger rsize= options and change defaults
  cifs: convert cifs_readpages to use async reads
  cifs: add cifs_async_readv
  cifs: fix protocol definition for READ_RSP
  cifs: add a callback function to receive the rest of the frame
  cifs: break out 3rd receive phase into separate function
  cifs: find mid earlier in receive codepath
  ...

* 'for-linus' of git://oss.sgi.com/xfs/xfs: (69 commits)
  xfs: add AIL pushing tracepoints
  xfs: put in missed fix for merge problem
  xfs: do not flush data workqueues in xfs_flush_buftarg
  xfs: remove XFS_bflush
  xfs: remove xfs_buf_target_name
  xfs: use xfs_ioerror_alert in xfs_buf_iodone_callbacks
  xfs: clean up xfs_ioerror_alert
  xfs: clean up buffer allocation
  xfs: remove buffers from the delwri list in xfs_buf_stale
  xfs: remove XFS_BUF_STALE and XFS_BUF_SUPER_STALE
  xfs: remove XFS_BUF_SET_VTYPE and XFS_BUF_SET_VTYPE_REF
  xfs: remove XFS_BUF_FINISH_IOWAIT
  xfs: remove xfs_get_buftarg_list
  xfs: fix buffer flushing during unmount
  xfs: optimize fsync on directories
  xfs: reduce the number of log forces from tail pushing
  xfs: Don't allocate new buffers on every call to _xfs_buf_find
  xfs: simplify xfs_trans_ijoin* again
  xfs: unlock the inode before log force in xfs_change_file_space
  xfs: unlock the inode before log force in xfs_fs_nfs_commit_metadata
  ...

In setlease, we use i_writecount to decide whether we can give out a
read lease.

In open, we break leases before incrementing i_writecount.

There is therefore a window between the break lease and the i_writecount
increment when setlease could add a new read lease.

This would leave us with a simultaneous write open and read lease, which
shouldn't happen.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This makes NFS follow the standard generic_file_llseek locking scheme.

Cc: Trond.Myklebust@netapp.com
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This gives ext4 the benefits of unlocked llseek.

Cc: tytso@mit.edu
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add a generic_file_llseek variant to the VFS that allows passing in
the maximum file size of the file system, instead of always
using maxbytes from the superblock.

This can be used to eliminate some cut'n'paste seek code in ext4.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The i_mutex lock use of generic _file_llseek hurts.  Independent processes
accessing the same file synchronize over a single lock, even though
they have no need for synchronization at all.

Under high utilization this can cause llseek to scale very poorly on larger
systems.

This patch does some rethinking of the llseek locking model:

First the 64bit f_pos is not necessarily atomic without locks
on 32bit systems. This can already cause races with read() today.
This was discussed on linux-kernel in the past and deemed acceptable.
The patch does not change that.

Let's look at the different seek variants:

SEEK_SET: Doesn't really need any locking.
If there's a race one writer wins, the other loses.

For 32bit the non atomic update races against read()
stay the same. Without a lock they can also happen
against write() now.  The read() race was deemed
acceptable in past discussions, and I think if it's
ok for read it's ok for write too.

=> Don't need a lock.

SEEK_END: This behaves like SEEK_SET plus it reads
the maximum size too. Reading the maximum size would have the
32bit atomic problem. But luckily we already have a way to read
the maximum size without locking (i_size_read), so we
can just use that instead.

Without i_mutex there is no synchronization with write() anymore,
however since the write() update is atomic on 64bit it just behaves
like another racy SEEK_SET.  On non atomic 32bit it's the same
as SEEK_SET.

=> Don't need a lock, but need to use i_size_read()

SEEK_CUR: This has a read-modify-write race window
on the same file. One could argue that any application
doing unsynchronized seeks on the same file is already broken.
But for the sake of not adding a regression here I'm
using the file->f_lock to synchronize this. Using this
lock is much better than the inode mutex because it doesn't
synchronize between processes.

=> So still need a lock, but can use a f_lock.

This patch implements this new scheme in generic_file_llseek.
I dropped generic_file_llseek_unlocked and changed all callers.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This doesn't change anything for the compiler, but hch thought it would
make the code clearer.

I moved the reference counting into its own little inline.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add inlines to all the submission path functions. While this increases
code size it also gives gcc a lot of optimization opportunities
in this critical hotpath.

In particular -- together with some other changes -- this
allows gcc to get rid of the unnecessary clearing of
sdio at the beginning and optimize the messy parameter passing.
Any non inlining of a function which takes a sdio parameter
would break this optimization because they cannot be done if the
address of a structure is taken.

Note that benefits are only seen with CONFIG_OPTIMIZE_INLINING
and CONFIG_CC_OPTIMIZE_FOR_SIZE both set to off.

This gives about 2.2% improvement on a large database benchmark
with a high IOPS rate.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Only a single b_private field in the map_bh buffer head is needed after
the submission path. Move map_bh separately to avoid storing
this information in the long term slab.

This avoids the weird 104 byte hole in struct dio_submit which also needed
to be memseted early.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

A direct slab call is slightly faster than kmalloc and can be better cached
per CPU. It also avoids rounding to the next kmalloc slab.

In addition this enforces cache line alignment for struct dio to avoid
any false sharing.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Fix most problems reported by pahole.

There is still a weird 104 byte hole after map_bh. I'm not sure what
causes this.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

There's nothing on the stack, even before my changes.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This large, but largely mechanic, patch moves all fields in struct dio
that are only used in the submission path into a separate on stack
data structure. This has the advantage that the memory is very likely
cache hot, which is not guaranteed for memory fresh out of kmalloc.

This also gives gcc more optimization potential because it can easier
determine that there are no external aliases for these variables.

The sdio initialization is a initialization now instead of memset.
This allows gcc to break sdio into individual fields and optimize
away unnecessary zeroing (after all the functions are inlined)
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We need to move the inode to the end of the list to actually make the
spinning prevention explained in the comment above it work.  With a
plain list_move it will simply stay in place as we're always reclaiming
from the head of the list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruen@kernel.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruen@kernel.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We are going to add more flags and having them in hex format
make it simpler
Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruen@kernel.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>