Ian Kent reports:
"I've noticed a couple of other regressions with the options vers
and proto option of mount.nfs(8).
The commands:
mount -t nfs -o vers=<invalid version> <server>:/<path> /<mountpoint>
mount -t nfs -o proto=<invalid proto> <server>:/<path> /<mountpoint>
both immediately fail.
But if the "-s" option is also used they both succeed with the
mount falling back to defaults (by the look of it).
In the past these failed even when the sloppy option was given, as
I think they should. I believe the sloppy option is meant to allow
the mount command to still function for mount options (for example
in shared autofs maps) that exist on other Unix implementations but
aren't present in the Linux mount.nfs(8). So, an invalid value
specified for a known mount option is different to an unknown mount
option and should fail appropriately."
See RH bugzilla 486266.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: Remove xdr_decode_fhstatus() and xdr_decode_fhstatus3(), now
that they are unused.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Solder xdr_stream-based XDR decoding functions into the in-kernel mountd
client that are more careful about checking data types and watching for
buffer overflows. The new MNT3 decoder includes support for auth-flavor
list decoding.
The "_sz" macro for MNT3 replies was missing the size of the file handle.
I've added this back, and included the size of the auth flavor array.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Introduce an xdr_stream-based XDR decoder that can unpack the auth-
flavor list returned in a MNT3 reply.
The nfs_mount() function's caller allocates an array, and passes the
size and a pointer to it. The decoder decodes all the flavors it can
into the array, and returns the number of decoded flavors.
If the caller is not interested in the auth flavors, it can pass a
value of zero as the size of the pre-allocated array.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Introduce xdr_stream-based XDR file handle decoders to the in-kernel
mountd client. These are more careful than the existing decoder
functions about buffer overflows and data type and range checking.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Introduce data structures and xdr_stream-based decoding functions for
unmarshalling mountd status codes properly.
Mountd version 3 uses specific standard error return codes that are
not errno values and not NFS3ERR_ values. These have a well-defined
standard mapping to local errno values. Introduce data structures
and a decoder function that map these status codes to local errno
values properly. This is new functionality (but not used yet).
Version 1 mountd status values are defined by RFC 1094 as UNIX error
values (errno values). Errno values on heterogeneous systems do not
necessarily match each other. To avoid exposing possibly incorrect
errno values to upper layers, the current XDR decoder converts all
non-zero MNT version 1 status codes to -EACCES.
The OpenGroup XNFS standard provides a mapping similar to but smaller
than the version 3 error codes. Implement a decoder that uses the XNFS
error codes, replacing the current decoder.
For both mountd protocol versions, map unrecognized errors to -EACCES.
Finally we introduce a replacement data structure for mnt_fhstatus
at this time, which is used by the new XDR decoders. In addition to
documenting that the status value returned by the XDR decoders is
always an errno, this new structure will be expanded in subsequent
patches.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: remove xdr_encode_dirpath() now that it has been replaced.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Check the length of the supplied dirpath, and see that it fits
properly in the RPC buffer.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: Relocate MNT program procedure number definitions to the
only file that uses them. Relocate the version number definitions,
which are shared, to nfs.h. Remove duplicate program number
definitions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cut NSM upcall RPC traffic in half -- don't do a NULL call first.
The cases where a ping would be helpful are rare.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When rpc.statd starts up in user space at boot time, it attempts to
write the latest NSM local state number into
/proc/sys/fs/nfs/nsm_local_state.
If lockd.ko isn't loaded yet (as is the case in most configurations),
that file doesn't exist, thus the kernel's NSM state remains set to
its initial value of zero during lockd operation.
This is a problem because rpc.statd and lockd use the NSM state number
to prevent repeated lock recovery on rebooted hosts. If lockd sends
a zero NSM state, but then a delayed SM_NOTIFY with a real NSM state
number is received, there is no way for lockd or rpc.statd to
distinguish that stale SM_NOTIFY from an actual reboot. Thus lock
recovery could be performed after the rebooted host has already
started reclaiming locks, and those locks will be lost.
We could change /etc/init.d/nfslock so it always modprobes lockd.ko
before starting rpc.statd. However, if lockd.ko is ever unloaded
and reloaded, we are back at square one, since the NSM state is not
preserved across an unload/reload cycle. This may happen frequently
on clients that use automounter. A period of NFS inactivity causes
lockd.ko to be unloaded, and the kernel loses its NSM state setting.
Instead, let's use the fact that rpc.statd plants the local system's
NSM state in every SM_MON (and SM_UNMON) reply. lockd performs a
synchronous SM_MON upcall to the local rpc.statd _before_ sending its
first NLM request to a new remote. This would permit rpc.statd to
provide the current NSM state to lockd, even after lockd.ko had been
unloaded and reloaded.
Note that NLMPROC_LOCK arguments are constructed before the
nsm_monitor() call, so we have to rearrange argument construction very
slightly to make this all work out.
And, the kernel appears to treat NSM state as a u32 (see struct
nlm_args and nsm_res). Make nsm_local_state a u32 as well, to ensure
we don't get bogus comparison results.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clear "ret" if the error return from svc_create_xprt(AF_INET6) was
-EAFNOSUPORT. Otherwise, callback start-up will succeed, but
nfs_callback_up() will return -EAFNOSUPPORT anyway, and the first
NFSv4 mount attempt after a reboot will fail.
Bug introduced by commit f738f517 in 2.6.30-rc1.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the kernel cannot start the NFSv4 callback service during a mount
request, it returns -ENOMEM to user space, resulting in this message:
mount.nfs4: Cannot allocate memory
Adjust nfs_alloc_client() and nfs_get_client() to pass NFSv4 callback
start-up errors back to user space so a less mysterious error message
can be displayed by the mount command.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The "intr" mount option has been deprecated for a while, but
/proc/mounts continues to display "nointr" whether "intr" or "nointr"
has been specified for a mount point.
Since these options do not have any effect, simply do not display
them.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Adds support for splice writes. It effectively calls
generic_file_splice_write() to do the writes.
We need not worry about O_APPEND case as the combination of splice()
writes and O_APPEND is disallowed. This patch propagates NFS write
errors back to the caller. The number of bytes written via splice are
being added to NFSIO_NORMALWRITTENBYTES as these are effectively
cached writes.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It is possible for servers to return NFS4ERR_BAD_STATEID when
the state management code is recovering locks or is reclaiming state when
returning a delegation. Ensure that we handle that case.
While we're at it, add in handlers for NFS4ERR_STALE,
NFS4ERR_ADMIN_REVOKED, NFS4ERR_OPENMODE, NFS4ERR_DENIED and
NFS4ERR_STALE_STATEID, since the protocol appears to allow for them too.
Also handle ENOMEM...
Finally, rather than add new NFSv4.0-specific errors and error handling into
the generic delegation code, move that open file and locking state error
handling into the NFSv4 layer.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The NFSv4 delegation recovery code is required by the protocol to handle
more errors. Rather than add NFSv4.0 specific errors into 'generic'
delegation code, we should move the error handling into the NFSv4 layer.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFSv4 should just ignore the 'nolock' option. It is an NFSv2/v3 thing...
This fixes the Oops in http://bugzilla.kernel.org/show_bug.cgi?id=13330
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6:
[SCSI] aic79xx: make driver respect nvram for IU and QAS settings
[SCSI] don't attach ULD to Dell Universal Xport
[SCSI] lpfc 8.3.3 : Update driver version to 8.3.3
[SCSI] lpfc 8.3.3 : Add support for Target Reset handler entrypoint
[SCSI] lpfc 8.3.3 : Fix a couple of spin_lock and memory issues and a crash
[SCSI] lpfc 8.3.3 : FC/FCOE discovery fixes
[SCSI] lpfc 8.3.3 : Fix various SLI-3 vs SLI-4 differences
[SCSI] qla2xxx: Resolve a performance issue in interrupt
[SCSI] cnic, bnx2i: Fix build failure when CONFIG_PCI is not set.
[SCSI] nsp_cs: time_out reaches -1
[SCSI] qla2xxx: fix printk format warnings
[SCSI] ncr53c8xx: div reaches -1
[SCSI] compat: don't perform unneeded copy in sg_io code
[SCSI] zfcp: Update FC pass-through support
[SCSI] zfcp: Add FC pass-through support
[SCSI] FC Pass Thru support
* 'linux-next' of git://git.infradead.org/ubifs-2.6:
UBIFS: start using hrtimers
hrtimer: export ktime_add_safe
UBIFS: do not forget to register BDI device
UBIFS: allow sync option in rootflags
UBIFS: remove dead code
UBIFS: use anonymous device
UBIFS: return proper error code if the compr is not present
UBIFS: return error if link and unlink race
UBIFS: reset no_space flag after inode deletion
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (47 commits)
MIPS: Add hibernation support
MIPS: Move Cavium CP0 hwrena impl bits to cpu-feature-overrides.h
MIPS: Allow CPU specific overriding of CP0 hwrena impl bits.
MIPS: Kconfig Add SYS_SUPPORTS_HUGETLBFS and enable it for some systems.
Hugetlbfs: Enable hugetlbfs for more systems in Kconfig.
MIPS: TLB support for hugetlbfs.
MIPS: Add hugetlbfs page defines.
MIPS: Add support files for hugetlbfs.
MIPS: Remove unused parameters from iPTE_LW.
Staging: Add octeon-ethernet driver files.
MIPS: Export erratum function needed by octeon-ethernet driver.
MIPS: Cavium-Octeon: Add more chip specific feature tests.
MIPS: Cavium-Octeon: Add more board type constants.
MIPS: Export cvmx_sysinfo_get needed by octeon-ethernet driver.
MIPS: Add named alloc functions to OCTEON boot monitor memory allocator.
MIPS: Alchemy: devboards: Convert to gpio calls.
MIPS: Alchemy: xxs1500: use linux gpio api.
MIPS: Alchemy: MTX-1: Use linux gpio api.
MIPS: Alchemy: Rewrite GPIO support.
MIPS: Alchemy: Remove unused au1000_gpio.h header
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
get rid of BKL in fs/sysv
get rid of BKL in fs/minix
get rid of BKL in fs/efs
befs ->pust_super() doesn't need BKL
Cleanup of adfs headers
9P doesn't need BKL in ->umount_begin()
fuse doesn't need BKL in ->umount_begin()
No instance of ->bmap() needs BKL
remove unlock_kernel() left accidentally
ext4: avoid unnecessary spinlock in critical POSIX ACL path
ext3: avoid unnecessary spinlock in critical POSIX ACL path
As part of adding hugetlbfs support for MIPS, I am adding a new
kconfig variable 'SYS_SUPPORTS_HUGETLBFS'. Since some mips cpu
varients don't yet support it, we can enable selection of HUGETLBFS on
a system by system basis from the arch/mips/Kconfig.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
CC: William Irwin <wli@holomorphy.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
commit 337eb00a2c
Push BKL down into ->remount_fs()
and
commit 4aa98cf768
Push BKL down into do_remount_sb()
were uncorrectly merged.
The former removes one pair of lock/unlock_kernel(), but the latter adds
several unlock_kernel(). Finally a few unlock_kernel() calls left.
Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If a filesystem supports POSIX ACL's, the VFS layer expects the filesystem
to do POSIX ACL checks on any files not owned by the caller, and it does
this for every single pathname component that it looks up.
That obviously can be pretty expensive if the filesystem isn't careful
about it, especially with locking. That's doubly sad, since the common
case tends to be that there are no ACL's associated with the files in
question.
ext4 already caches the ACL data so that it doesn't have to look it up
over and over again, but it does so by taking the inode->i_lock spinlock
on every lookup. Which is a noticeable overhead even if it's a private
lock, especially on CPU's where the serialization is expensive (eg Intel
Netburst aka 'P4').
For the special case of not actually having any ACL's, all that locking is
unnecessary. Even if somebody else were to be changing the ACL's on
another CPU, we simply don't care - if we've seen a NULL ACL, we might as
well use it.
So just load the ACL speculatively without any locking, and if it was
NULL, just use it. If it's non-NULL (either because we had a cached
entry, or because the cache hasn't been filled in at all), it means that
we'll need to get the lock and re-load it properly.
(This commit was ported from a patch originally authored by Linus for
ext3.)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If a filesystem supports POSIX ACL's, the VFS layer expects the filesystem
to do POSIX ACL checks on any files not owned by the caller, and it does
this for every single pathname component that it looks up.
That obviously can be pretty expensive if the filesystem isn't careful
about it, especially with locking. That's doubly sad, since the common
case tends to be that there are no ACL's associated with the files in
question.
ext3 already caches the ACL data so that it doesn't have to look it up
over and over again, but it does so by taking the inode->i_lock spinlock
on every lookup. Which is a noticeable overhead even if it's a private
lock, especially on CPU's where the serialization is expensive (eg Intel
Netburst aka 'P4').
For the special case of not actually having any ACL's, all that locking is
unnecessary. Even if somebody else were to be changing the ACL's on
another CPU, we simply don't care - if we've seen a NULL ACL, we might as
well use it.
So just load the ACL speculatively without any locking, and if it was
NULL, just use it. If it's non-NULL (either because we had a cached
entry, or because the cache hasn't been filled in at all), it means that
we'll need to get the lock and re-load it properly.
This is noticeable even on Nehalem, which does locking quite well (much
better than P4). From lmbench:
Processor, Processes - times in microseconds - smaller is better
--------------------------------------------------------------------
Host OS Mhz null null open slct fork exec sh
call I/O stat clos TCP proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ----
- before:
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.45 2.18 69.1 273. 1141
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.48 2.28 69.9 253. 1140
nehalem.l Linux 2.6.30- 3193 0.04 0.10 0.95 1.42 2.19 68.6 284. 1141
- after:
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.44 2.12 68.3 282. 1094
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.20 67.0 308. 1123
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.36 67.4 293. 1148
where you can see what appears to be a roughly 3% improvement in stat
and open/close latencies from just the removal of the locking overhead.
Of course, this only matters for files you don't own (the owner never
needs to do the ACL checks), but that's the common case for libraries,
header files, and executables. As well as for the base components of any
absolute pathname, even if you are the owner of the final file.
[ At some point we probably want to move this ACL caching logic entirely
into the VFS layer (and only call down to the filesystem when
uncached), but in the meantime this improves ext3 a bit.
A similar fix to btrfs makes a much bigger difference (15x improvement
in lmbench) due to broken caching. ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Authentication error abort codes should be translated to appropriate
Linux error codes, rather than all being translated to EREMOTEIO - which
indicates that the server had internal problems.
Additionally, a server shouldn't be marked unavailable and the next
server tried if an authentication error occurs. This will quickly make
all the servers unavailable to the client. Instead the error should be
returned straight to the user.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* akpm: (182 commits)
fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
fbdev: *bfin*: fix __dev{init,exit} markings
fbdev: *bfin*: drop unnecessary calls to memset
fbdev: bfin-t350mcqb-fb: drop unused local variables
fbdev: blackfin has __raw I/O accessors, so use them in fb.h
fbdev: s1d13xxxfb: add accelerated bitblt functions
tcx: use standard fields for framebuffer physical address and length
fbdev: add support for handoff from firmware to hw framebuffers
intelfb: fix a bug when changing video timing
fbdev: use framebuffer_release() for freeing fb_info structures
radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
s3c-fb: CPUFREQ frequency scaling support
s3c-fb: fix resource releasing on error during probing
carminefb: fix possible access beyond end of carmine_modedb[]
acornfb: remove fb_mmap function
mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
mb862xxfb: restrict compliation of platform driver to PPC
Samsung SoC Framebuffer driver: add Alpha Channel support
atmel-lcdc: fix pixclock upper bound detection
offb: use framebuffer_alloc() to allocate fb_info struct
...
Manually fix up conflicts due to kmemcheck in mm/slab.c
CONFIG_FILE_LOCKING should not depend on CONFIG_BLOCK.
This makes it possible to run complete systems out of a CONFIG_BLOCK=n
initramfs on current kernels again (this last worked on 2.6.27.*).
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
put_cpu_no_resched() is an optimization of put_cpu() which unfortunately
can cause high latencies.
The nfs iostats code uses put_cpu_no_resched() in a code sequence where a
reschedule request caused by an interrupt between the get_cpu() and the
put_cpu_no_resched() can delay the reschedule for at least HZ.
The other users of put_cpu_no_resched() optimize correctly in interrupt
code, but there is no real harm in using the put_cpu() function which is
an alias for preempt_enable(). The extra check of the preemmpt count is
not as critical as the potential source of missing a reschedule.
Debugged in the preempt-rt tree and verified in mainline.
Impact: remove a high latency source
[akpm@linux-foundation.org: build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After introduction of keyed wakeups Davide Libenzi did on epoll, we are
able to avoid spurious wakeups in poll()/select() code too.
For example, typical use of poll()/select() is to wait for incoming
network frames on many sockets. But TX completion for UDP/TCP frames call
sock_wfree() which in turn schedules thread.
When scheduled, thread does a full scan of all polled fds and can sleep
again, because nothing is really available. If number of fds is large,
this cause significant load.
This patch makes select()/poll() aware of keyed wakeups and useless
wakeups are avoided. This reduces number of context switches by about 50%
on some setups, and work performed by sofirq handlers.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1) I_FREEING tests should be coupled with I_CLEAR
The two I_FREEING tests are racy because clear_inode() can set i_state to
I_CLEAR between the clear of I_SYNC and the test of I_FREEING.
2) skip I_WILL_FREE inodes in generic_sync_sb_inodes() to avoid possible
races with generic_forget_inode()
generic_forget_inode() sets I_WILL_FREE call writeback on its own, so
generic_sync_sb_inodes() shall not try to step in and create possible races:
generic_forget_inode
inode->i_state |= I_WILL_FREE;
spin_unlock(&inode_lock);
generic_sync_sb_inodes()
spin_lock(&inode_lock);
__iget(inode);
__writeback_single_inode
// see non zero i_count
may WARN here ==> WARN_ON(inode->i_state & I_WILL_FREE);
spin_unlock(&inode_lock);
may call generic_forget_inode again ==> iput(inode);
The above race and warning didn't turn up because writeback_inodes() holds
the s_umount lock, so generic_forget_inode() finds MS_ACTIVE and returns
early. But we are not sure the UBIFS calls and future callers will
guarantee that. So skip I_WILL_FREE inodes for the sake of safety.
Cc: Eric Sandeen <sandeen@sandeen.net>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove __invalidate_mapping_pages atomic variant now that its sole caller
can sleep (fixed in eccb95cee4 ("vfs: fix
lock inversion in drop_pagecache_sb()")).
This fixes softlockups that can occur while in the drop_caches path.
Signed-off-by: Mike Waychison <mikew@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The per-task oom_adj value is a characteristic of its mm more than the
task itself since it's not possible to oom kill any thread that shares the
mm. If a task were to be killed while attached to an mm that could not be
freed because another thread were set to OOM_DISABLE, it would have
needlessly been terminated since there is no potential for future memory
freeing.
This patch moves oomkilladj (now more appropriately named oom_adj) from
struct task_struct to struct mm_struct. This requires task_lock() on a
task to check its oom_adj value to protect against exec, but it's already
necessary to take the lock when dereferencing the mm to find the total VM
size for the badness heuristic.
This fixes a livelock if the oom killer chooses a task and another thread
sharing the same memory has an oom_adj value of OOM_DISABLE. This occurs
because oom_kill_task() repeatedly returns 1 and refuses to kill the
chosen task while select_bad_process() will repeatedly choose the same
task during the next retry.
Taking task_lock() in select_bad_process() to check for OOM_DISABLE and in
oom_kill_task() to check for threads sharing the same memory will be
removed in the next patch in this series where it will no longer be
necessary.
Writing to /proc/pid/oom_adj for a kthread will now return -EINVAL since
these threads are immune from oom killing already. They simply report an
oom_adj value of OOM_DISABLE.
Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Export all page flags faithfully in /proc/kpageflags.
11. KPF_MMAP (pseudo flag) memory mapped page
12. KPF_ANON (pseudo flag) memory mapped page (anonymous)
13. KPF_SWAPCACHE page is in swap cache
14. KPF_SWAPBACKED page is swap/RAM backed
15. KPF_COMPOUND_HEAD (*)
16. KPF_COMPOUND_TAIL (*)
17. KPF_HUGE hugeTLB pages
18. KPF_UNEVICTABLE page is in the unevictable LRU list
19. KPF_HWPOISON(TBD) hardware detected corruption
20. KPF_NOPAGE (pseudo flag) no page frame at the address
32-39. more obscure flags for kernel developers
(*) For compound pages, exporting _both_ head/tail info enables
users to tell where a compound page starts/ends, and its order.
The accompanying page-types tool will handle the details like decoupling
overloaded flags and hiding obscure flags to normal users.
Thanks to KOSAKI and Andi for their valuable recommendations!
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
send_sigio_to_task() reads fown->signum several times, we can race with
F_SETSIG which changes ->signum lockless. In theory, this can fool
security checks or we can call group_send_sig_info() with the wrong
->si_signo which does not match "int sig".
Change the code to cache ->signum.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
