Most of the btrfs metadata operations can be protected by a spinlock,
but some operations still need to schedule.
So far, btrfs has been using a mutex along with a trylock loop,
most of the time it is able to avoid going for the full mutex, so
the trylock loop is a big performance gain.
This commit is step one for getting rid of the blocking locks entirely.
btrfs_tree_lock takes a spinlock, and the code explicitly switches
to a blocking lock when it starts an operation that can schedule.
We'll be able get rid of the blocking locks in smaller pieces over time.
Tracing allows us to find the most common cause of blocking, so we
can start with the hot spots first.
The basic idea is:
btrfs_tree_lock() returns with the spin lock held
btrfs_set_lock_blocking() sets the EXTENT_BUFFER_BLOCKING bit in
the extent buffer flags, and then drops the spin lock. The buffer is
still considered locked by all of the btrfs code.
If btrfs_tree_lock gets the spinlock but finds the blocking bit set, it drops
the spin lock and waits on a wait queue for the blocking bit to go away.
Much of the code that needs to set the blocking bit finishes without actually
blocking a good percentage of the time. So, an adaptive spin is still
used against the blocking bit to avoid very high context switch rates.
btrfs_clear_lock_blocking() clears the blocking bit and returns
with the spinlock held again.
btrfs_tree_unlock() can be called on either blocking or spinning locks,
it does the right thing based on the blocking bit.
ctree.c has a helper function to set/clear all the locked buffers in a
path as blocking.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Before metadata is written to disk, it is updated to reflect that writeout
has begun. Once this update is done, the block must be cow'd before it
can be modified again.
This update was originally synchronized by using a per-fs spinlock. Today
the buffers for the metadata blocks are locked before writeout begins,
and everyone that tests the flag has the buffer locked as well.
So, the per-fs spinlock (called hash_lock for no good reason) is no
longer required.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
extent_io.c has debugging code to report and free leaked extent_state
and extent_buffer objects at rmmod time. This helps track down
leaks and it saves you from rebooting just to properly remove the
kmem_cache object.
But, the code runs under a fairly expensive spinlock and the checks to
see if it is currently enabled are not entirely consistent. Some use
#ifdef and some #if.
This changes everything to #if and disables the leak checking.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When a block goes through cow, we update the reference counts of
everything that block points to. The internal pointers of the block
can be in just about any order, and it is likely to have clusters of
things that are close together and clusters of things that are not.
To help reduce the seeks that come with updating all of these reference
counts, sort them by byte number before actual updates are done.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Tracing shows the delay between when an async thread goes to sleep
and when more work is added is often very short. This commit adds
a little bit of delay and extra checking to the code right before
we schedule out.
It allows more work to be added to the worker
without requiring notifications from other procs.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Add call to LSM security initialization and save
resulting security xattr for new inodes.
Add xattr support to symlink inode ops.
Set inode->i_op for existing special files.
Signed-off-by: jim owens <jowens@hp.com>
This patch adds a menu entry to kconfig to enable acls for btrfs.
This allows you to enable FS_POSIX_ACL at kernel compile time.
(updated by Jeff Mahoney to make the changes in fs/btrfs/Kconfig instead)
Signed-off-by: Christian Hesse <mail@earthworm.de>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
The async bio submission thread was missing some bios that were
added after it had decided there was no work left to do.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
After btrfs_readdir has gone through all the directory items, it
sets the directory f_pos to the largest possible int. This way
applications that mix readdir with creating new files don't
end up in an endless loop finding the new directory items as they go.
It was a workaround for a bug in git, but the assumption was that if git
could make this looping mistake than it would be a common problem.
The largest possible int chosen was INT_LIMIT(typeof(file->f_pos),
and it is possible for that to be a larger number than 32 bit glibc
expects to come out of readdir.
This patches switches that to INT_LIMIT(off_t), which should keep
applications happy on 32 and 64 bit machines.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/mm: Fix handling of _PAGE_COHERENT in BAT setup code
powerpc/pseries: Correct VIO bus accounting problem in CMO env.
powerpc: More printing warning fixes for the l64 to ll64 conversion
powerpc: Remove arch/ppc cruft from Kconfig
powerpc: Printing fix for l64 to ll64 conversion: phyp_dump.c
powerpc/embedded6xx: Update defconfigs
powerpc/8xx: Update defconfigs
powerpc/86xx: Update defconfigs
powerpc/83xx: Update defconfigs
powerpc/85xx: Update defconfigs
powerpc/mpc8313erdb: fix kernel panic because mdio device is not probed
powerpc/4xx: Update multi-board PowerPC 4xx defconfigs
powerpc/44x: Update PowerPC 44x defconfigs
powerpc/40x: Update PowerPC 40x defconfigs
powerpc/85xx: Fix typo in mpc8572ds dts
powerpc/44x: Warp patches for the new NDFC driver
powerpc/4xx: DTS: Add Add'l SDRAM0 Compatible and Interrupt Info
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68knommu: fix 5329 ColdFire periphal addressing
uclinux: add process name to allocation error message
m68knommu: correct the mii calculations for 532x ColdFire FEC
m68knommu: add ColdFire M532x to the FEC configuration options
m68knommu: fix syscall restarting
m68knommu: remove the obsolete and long unused comempci chip support
m68knommu: remove the no longer used PCI support option
m68knommu: remove obsolete and unused eLIA board
m68knommu: set NO_DMA
m68knommu: fix cache flushing for the 527x ColdFire processors
m68knommu: fix ColdFire 5272 serial baud rates in mcf.c
m68knommu: use one exist from execption
Commit d7b1956fed ("DMI: Introduce
dmi_first_match to make the interface more flexible") introduced compile
errors like the following when !CONFIG_DMI
drivers/ata/sata_sil.c: In function 'sil_broken_system_poweroff':
drivers/ata/sata_sil.c:713: error: implicit declaration of function 'dmi_first_match'
drivers/ata/sata_sil.c:713: warning: initialization makes pointer from integer without a cast
We just need a dummy version of dmi_first_match() to fix this all up.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Schedule a vblank signal, kill the process, and we'll go walking over freed
memory. Given that no open-source userland exists using this, nor have I
ever heard of a consumer, just let this code die.
Signed-off-by: Eric Anholt <eric@anholt.net>
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
_PAGE_COHERENT is now always set in _PAGE_RAM resp. PAGE_KERNEL.
Thus it has to be masked out, if the BAT mapping should be non
cacheable or CPU_FTR_NEED_COHERENT is not set.
This will work on normal SMP setups because we force-set
CPU_FTR_NEED_COHERENT as part of CPU_FTR_COMMON on SMP.
Signed-off-by: Gerhard Pircher <gerhard_pircher@gmx.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In the VIO bus code the wrappers for dma alloc_coherent and free_coherent
calls are rounding to IOMMU_PAGE_SIZE. Taking a look at the underlying
calls, the actual mapping is promoted to PAGE_SIZE. Changing the
rounding in these two functions fixes under-reporting the entitlement
used by the system. Without this change, the system could run out of
entitlement before it believes it has and incur mapping failures at the
firmware level.
Also in the VIO bus code, the wrapper for dma map_sg is not exiting in
an error path where it should. Rather than fall through to code for the
success case, this patch adds the return that is needed in the error path.
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
These are all powerpc specific drivers.
res.start in fsl_elbc_nand.c needs to be cast since it may be either 32
or 64 bit. Thanks to Scott Wood for noticing.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de> call_edac bits in particular
Acked-by: Olof Johansson <olof@lixom.net> pasemi_nand peices
Acked-by: Scott Wood <scottwood@freescale.com> fsl_elbc fixes
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Given just how hard it is to find the code that uses MAY_APPEND
it's probably not a big surprise that this went unnoticed for so
long. The Smack rules loading code is incorrectly setting the
MAY_READ bit when MAY_APPEND is requested.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (36 commits)
USB: Driver for Freescale QUICC Engine USB Host Controller
USB: option: add QUANTA HSDPA Data Card device ids
USB: storage: Add another unusual_dev for off-by-one bug
USB: unusual_dev: usb-storage needs to ignore a device
USB: GADGET: fix !x & y
USB: new id for ti_usb_3410_5052 driver
USB: cdc-acm: Add another conexant modem to the quirks
USB: 'option' driver - onda device MT503HS has wrong id
USB: Remove ZTE modem from unusual_devices
USB: storage: support of Dane-Elec MediaTouch USB device
USB: usbmon: Implement compat_ioctl
USB: add kernel-doc for wusb_dev in struct usb_device
USB: ftdi_sio driver support of bar code scanner from Diebold
USB: ftdi_sio: added Alti-2 VID and Neptune 3 PID
USB: cp2101 device
USB: usblp.c: add USBLP_QUIRK_BIDIR to Brother HL-1440
USB: remove vernier labpro from ldusb
USB: CDC-ACM quirk for MTK GPS
USB: cdc-acm: support some gps data loggers
USB: composite: Fix bug: low byte of w_index is the usb interface number not the whole 2 bytes of w_index
...
This patch adds support for the FHCI USB controller, as found
in the Freescale MPC836x and MPC832x processors. It can support
Full or Low speed modes.
Quite a lot the hardware is doing by itself (SOF generation, CRC
generation and checking), though scheduling and retransmission is on
software's shoulders.
This controller does not integrate the root hub, so this driver also
fakes one-port hub. External hub is required to support more than
one device.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
