linux/fs, branch v2.6.36-rc4

Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

2010-09-11T01:19:26Z

* 'for-linus' of git://oss.sgi.com/xfs/xfs: xfs: log IO completion workqueue is a high priority queue xfs: prevent reading uninitialized stack memory

xfs: log IO completion workqueue is a high priority queue

2010-09-10T15:16:54Z

The workqueue implementation in 2.6.36-rcX has changed, resulting in the workqueues no longer having dedicated threads for work processing. This has caused severe livelocks under heavy parallel create workloads because the log IO completions have been getting held up behind metadata IO completions. Hence log commits would stall, memory allocation would stall because pages could not be cleaned, and lock contention on the AIL during inode IO completion processing was being seen to slow everything down even further. By making the log Io completion workqueue a high priority workqueue, they are queued ahead of all data/metadata IO completions and processed before the data/metadata completions. Hence the log never gets stalled, and operations needed to clean memory can continue as quickly as possible. This avoids the livelock conditions and allos the system to keep running under heavy load as per normal. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Alex Elder

execve: make responsive to SIGKILL with large arguments

2010-09-10T15:10:26Z

An execve with a very large total of argument/environment strings can take a really long time in the execve system call. It runs uninterruptibly to count and copy all the strings. This change makes it abort the exec quickly if sent a SIGKILL. Note that this is the conservative change, to interrupt only for SIGKILL, by using fatal_signal_pending(). It would be perfectly correct semantics to let any signal interrupt the string-copying in execve, i.e. use signal_pending() instead of fatal_signal_pending(). We'll save that change for later, since it could have user-visible consequences, such as having a timer set too quickly make it so that an execve can never complete, though it always happened to work before. Signed-off-by: Roland McGrath Reviewed-by: KOSAKI Motohiro Signed-off-by: Linus Torvalds

execve: improve interactivity with large arguments

2010-09-10T15:10:26Z

This adds a preemption point during the copying of the argument and environment strings for execve, in copy_strings(). There is already a preemption point in the count() loop, so this doesn't add any new points in the abstract sense. When the total argument+environment strings are very large, the time spent copying them can be much more than a normal user time slice. So this change improves the interactivity of the rest of the system when one process is doing an execve with very large arguments. Signed-off-by: Roland McGrath Reviewed-by: KOSAKI Motohiro Signed-off-by: Linus Torvalds

setup_arg_pages: diagnose excessive argument size

2010-09-10T15:10:26Z

The CONFIG_STACK_GROWSDOWN variant of setup_arg_pages() does not check the size of the argument/environment area on the stack. When it is unworkably large, shift_arg_pages() hits its BUG_ON. This is exploitable with a very large RLIMIT_STACK limit, to create a crash pretty easily. Check that the initial stack is not too large to make it possible to map in any executable. We're not checking that the actual executable (or intepreter, for binfmt_elf) will fit. So those mappings might clobber part of the initial stack mapping. But that is just userland lossage that userland made happen, not a kernel problem. Signed-off-by: Roland McGrath Reviewed-by: KOSAKI Motohiro Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2010-09-10T14:26:27Z

* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: Range check cpu in blk_cpu_to_group scatterlist: prevent invalid free when alloc fails writeback: Fix lost wake-up shutting down writeback thread writeback: do not lose wakeup events when forking bdi threads cciss: fix reporting of max queue depth since init block: switch s390 tape_block and mg_disk to elevator_change() block: add function call to switch the IO scheduler from a driver fs/bio-integrity.c: return -ENOMEM on kmalloc failure bio-integrity.c: remove dependency on __GFP_NOFAIL BLOCK: fix bio.bi_rw handling block: put dev->kobj in blk_register_queue fail path cciss: handle allocation failure cfq-iosched: Documentation help for new tunables cfq-iosched: blktrace print per slice sector stats cfq-iosched: Implement tunable group_idle cfq-iosched: Do group share accounting in IOPS when slice_idle=0 cfq-iosched: Do not idle if slice_idle=0 cciss: disable doorbell reset on reset_devices blkio: Fix return code for mkdir calls

xfs: prevent reading uninitialized stack memory

2010-09-10T12:39:28Z

The XFS_IOC_FSGETXATTR ioctl allows unprivileged users to read 12 bytes of uninitialized stack memory, because the fsxattr struct declared on the stack in xfs_ioc_fsgetxattr() does not alter (or zero) the 12-byte fsx_pad member before copying it back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg Reviewed-by: Eric Sandeen Signed-off-by: Alex Elder

minix: fix regression in minix_mkdir()

2010-09-10T01:57:25Z

Commit 9eed1fb721c ("minix: replace inode uid,gid,mode init with helper") broke directory creation on minix filesystems. Fix it by passing the needed mode flag to inode init helper. Signed-off-by: Jorge Boncompte [DTI2] Cc: Dmitry Monakhov Cc: Al Viro Cc: [2.6.35.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfs: take O_NONBLOCK out of the O_* uniqueness test

2010-09-10T01:57:25Z

O_NONBLOCK on parisc has a dual value: #define O_NONBLOCK 000200004 /* HPUX has separate NDELAY & NONBLOCK */ It is caught by the O_* bits uniqueness check and leads to a parisc compile error. The fix would be to take O_NONBLOCK out. Signed-off-by: Wu Fengguang Signed-off-by: James Bottomley Cc: Jamie Lokier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

binfmt_misc: fix binfmt_misc priority

2010-09-10T01:57:24Z

Commit 74641f584da ("alpha: binfmt_aout fix") (May 2009) introduced a regression - binfmt_misc is now consulted after binfmt_elf, which will unfortunately break ia32el. ia32 ELF binaries on ia64 used to be matched using binfmt_misc and executed using wrapper. As 32bit binaries are now matched by binfmt_elf before bindmt_misc kicks in, the wrapper is ignored. The fix increases precedence of binfmt_misc to the original state. Signed-off-by: Jan Sembera Cc: Ivan Kokshaysky Cc: Al Viro Cc: Richard Henderson [2.6.everything.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds