user/sven/linux.git/include/linux/fdtable.h, branch v3.4.40

Replace the fd_sets in struct fdtable with an array of unsigned longs

2012-02-19T18:30:57Z

Replace the fd_sets in struct fdtable with an array of unsigned longs and then use the standard non-atomic bit operations rather than the FD_* macros. This: (1) Removes the abuses of struct fd_set: (a) Since we don't want to allocate a full fd_set the vast majority of the time, we actually, in effect, just allocate a just-big-enough array of unsigned longs and cast it to an fd_set type - so why bother with the fd_set at all? (b) Some places outside of the core fdtable handling code (such as SELinux) want to look inside the array of unsigned longs hidden inside the fd_set struct for more efficient iteration over the entire set. (2) Eliminates the use of FD_*() macros in the kernel completely. (3) Permits the __FD_*() macros to be deleted entirely where not exposed to userspace. Signed-off-by: David Howells Link: http://lkml.kernel.org/r/20120216174954.23314.48147.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin Cc: Al Viro

Wrap accesses to the fd_sets in struct fdtable

2012-02-19T18:30:52Z

Wrap accesses to the fd_sets in struct fdtable (for recording open files and close-on-exec flags) so that we can move away from using fd_sets since we abuse the fd_set structs by not allocating the full-sized structure under normal circumstances and by non-core code looking at the internals of the fd_sets. The first abuse means that use of FD_ZERO() on these fd_sets is not permitted, since that cannot be told about their abnormal lengths. This introduces six wrapper functions for setting, clearing and testing close-on-exec flags and fd-is-open flags: void __set_close_on_exec(int fd, struct fdtable *fdt); void __clear_close_on_exec(int fd, struct fdtable *fdt); bool close_on_exec(int fd, const struct fdtable *fdt); void __set_open_fd(int fd, struct fdtable *fdt); void __clear_open_fd(int fd, struct fdtable *fdt); bool fd_is_open(int fd, const struct fdtable *fdt); Note that I've prepended '__' to the names of the set/clear functions because they require the caller to hold a lock to use them. Note also that I haven't added wrappers for looking behind the scenes at the the array. Possibly that should exist too. Signed-off-by: David Howells Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin Cc: Al Viro

atomic: use

2011-07-26T23:49:47Z

This allows us to move duplicated code in (atomic_inc_not_zero() for now) to Signed-off-by: Arun Sharma Reviewed-by: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Cc: Eric Dumazet Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check

2011-07-08T20:21:58Z

Since ca5ecddf (rcu: define __rcu address space modifier for sparse) rcu_dereference_check use rcu_read_lock_held as a part of condition automatically so callers do not have to do that as well. Signed-off-by: Michal Hocko Acked-by: Paul E. McKenney Signed-off-by: Jiri Kosina

kernel: __rcu annotations

2010-08-20T00:18:03Z

This adds annotations for RCU operations in core kernel components Signed-off-by: Arnd Bergmann Signed-off-by: Paul E. McKenney Cc: Al Viro Cc: Jens Axboe Cc: Andrew Morton Reviewed-by: Josh Triplett

Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2010-08-06T16:23:07Z

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: Revert "net: Make accesses to ->br_port safe for sparse RCU" mce: convert to rcu_dereference_index_check() net: Make accesses to ->br_port safe for sparse RCU vfs: add fs.h to define struct file lockdep: Add an in_workqueue_context() lockdep-based test function rcu: add __rcu API for later sparse checking rcu: add an rcu_dereference_index_check() tree/tiny rcu: Add debug RCU head objects mm: remove all rcu head initializations fs: remove all rcu head initializations, except on_stack initializations powerpc: remove all rcu head initializations

vfs: fix RCU-lockdep false positive due to /proc

2010-07-20T23:25:41Z

If a single-threaded process does a file-descriptor operation, and some other process accesses that same file descriptor via /proc, the current rcu_dereference_check_fdtable() can give a false-positive RCU-lockdep splat due to the reference count being increased by the /proc access after the reference-count check in fget_light() but before the check in rcu_dereference_check_fdtable(). This commit prevents this false positive by checking for a single-threaded process. To avoid #include hell, this commit uses the wrapper for thread_group_empty(current) defined by rcu_my_thread_group_empty() provided in a separate commit. Located-by: Miles Lane Located-by: Eric Dumazet Signed-off-by: Paul E. McKenney Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfs: add fs.h to define struct file

2010-06-14T23:37:27Z

The sparse RCU-pointer annotations require definition of the underlying type of any pointer passed to rcu_dereference() and friends. So fcheck_files() needs "struct file" to be defined, so include fs.h. Signed-off-by: Arnd Bergmann Signed-off-by: Paul E. McKenney Cc: Al Viro

vfs: Abstract rcu_dereference_check for files-fdtable use

2010-02-25T09:34:49Z

Create an rcu_dereference_check_fdtable() that encapsulates the rcu_dereference_check() condition for fcheck_files() use. This has the beneficial side-effect of getting rid of a very long line. Suggested-by: Peter Zijlstra Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-9-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar

vfs: Apply lockdep-based checking to rcu_dereference() uses

2010-02-25T09:34:48Z

Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable() and fcheck_files(). Cc: Alexander Viro Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: Alexander Viro LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar