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2014-05-07fs/file.c: don't open-code kvfree()Al Viro1-8/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-13Merge branch 'for-linus' of ↵Linus Torvalds1-7/+4
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
2014-04-02get rid of files_defer_init()Al Viro1-7/+4
the only thing it's doing these days is calculation of upper limit for fs.nr_open sysctl and that can be done statically Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-03-31Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "Main changes: - Torture-test changes, including refactoring of rcutorture and introduction of a vestigial locktorture. - Real-time latency fixes. - Documentation updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) rcu: Provide grace-period piggybacking API rcu: Ensure kernel/rcu/rcu.h can be sourced/used stand-alone rcu: Fix sparse warning for rcu_expedited from kernel/ksysfs.c notifier: Substitute rcu_access_pointer() for rcu_dereference_raw() Documentation/memory-barriers.txt: Clarify release/acquire ordering rcutorture: Save kvm.sh output to log rcutorture: Add a lock_busted to test the test rcutorture: Place kvm-test-1-run.sh output into res directory rcutorture: Rename TREE_RCU-Kconfig.txt locktorture: Add kvm-recheck.sh plug-in for locktorture rcutorture: Gracefully handle NULL cleanup hooks locktorture: Add vestigial locktorture configuration rcutorture: Introduce "rcu" directory level underneath configs rcutorture: Rename kvm-test-1-rcu.sh rcutorture: Remove RCU dependencies from ver_functions.sh API rcutorture: Create CFcommon file for common Kconfig parameters rcutorture: Create config files for scripted test-the-test testing rcutorture: Add an rcu_busted to test the test locktorture: Add a lock-torture kernel module rcutorture: Abstract kvm-recheck.sh ...
2014-03-23vfs: Don't let __fdget_pos() get FMODE_PATH filesEric Biggers1-15/+4
Commit bd2a31d522344 ("get rid of fget_light()") introduced the __fdget_pos() function, which returns the resulting file pointer and fdput flags combined in an 'unsigned long'. However, it also changed the behavior to return files with FMODE_PATH set, which shouldn't happen because read(), write(), lseek(), etc. aren't allowed on such files. This commit restores the old behavior. This regression actually had no effect on read() and write() since FMODE_READ and FMODE_WRITE are not set on file descriptors opened with O_PATH, but it did cause lseek() on a file descriptor opened with O_PATH to fail with ESPIPE rather than EBADF. Signed-off-by: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-03-10get rid of fget_light()Al Viro1-13/+43
instead of returning the flags by reference, we can just have the low-level primitive return those in lower bits of unsigned long, with struct file * derived from the rest. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-02-18fs: Substitute rcu_access_pointer() for rcu_dereference_raw()Paul E. McKenney1-1/+1
(Trivial patch.) If the code is looking at the RCU-protected pointer itself, but not dereferencing it, the rcu_dereference() functions can be downgraded to rcu_access_pointer(). This commit makes this downgrade in __alloc_fd(), which simply compares the RCU-protected pointer against NULL with no dereferencing. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2014-02-11fs/file.c:fdtable: avoid triggering OOMs from alloc_fdmemEric W. Biederman1-1/+1
Recently due to a spike in connections per second memcached on 3 separate boxes triggered the OOM killer from accept. At the time the OOM killer was triggered there was 4GB out of 36GB free in zone 1. The problem was that alloc_fdtable was allocating an order 3 page (32KiB) to hold a bitmap, and there was sufficient fragmentation that the largest page available was 8KiB. I find the logic that PAGE_ALLOC_COSTLY_ORDER can't fail pretty dubious but I do agree that order 3 allocations are very likely to succeed. There are always pathologies where order > 0 allocations can fail when there are copious amounts of free memory available. Using the pigeon hole principle it is easy to show that it requires 1 page more than 50% of the pages being free to guarantee an order 1 (8KiB) allocation will succeed, 1 page more than 75% of the pages being free to guarantee an order 2 (16KiB) allocation will succeed and 1 page more than 87.5% of the pages being free to guarantee an order 3 allocate will succeed. A server churning memory with a lot of small requests and replies like memcached is a common case that if anything can will skew the odds against large pages being available. Therefore let's not give external applications a practical way to kill linux server applications, and specify __GFP_NORETRY to the kmalloc in alloc_fdmem. Unless I am misreading the code and by the time the code reaches should_alloc_retry in __alloc_pages_slowpath (where __GFP_NORETRY becomes signification). We have already tried everything reasonable to allocate a page and the only thing left to do is wait. So not waiting and falling back to vmalloc immediately seems like the reasonable thing to do even if there wasn't a chance of triggering the OOM killer. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Cong Wang <cwang@twopensource.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-25fs: __fget_light() can use __fget() in slow pathOleg Nesterov1-11/+3
The slow path in __fget_light() can use __fget() to avoid the code duplication. Saves 232 bytes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: factor out common code in fget_light() and fget_raw_light()Oleg Nesterov1-24/+9
Apart from FMODE_PATH check fget_light() and fget_raw_light() are identical, shift the code into the new helper, __fget_light(fd, mask). Saves 208 bytes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25fs: factor out common code in fget() and fget_raw()Oleg Nesterov1-17/+8
Apart from FMODE_PATH check fget() and fget_raw() are identical, shift the code into the new simple helper, __fget(fd, mask). Saves 160 bytes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25change close_files() to use rcu_dereference_raw(files->fdt)Oleg Nesterov1-17/+9
put_files_struct() and close_files() do rcu_read_lock() to make rcu_dereference_check_fdtable() happy. This looks a bit ugly, files_fdtable() just reads the pointer, we can simply use rcu_dereference_raw() to avoid the warning. The patch also changes close_files() to return fdt, this avoids another rcu_read_lock()/files_fdtable() in put_files_struct(). I think close_files() needs more cleanups: - we do not need xchg() exactly because we are the last user of this files_struct - "if (file)" should be turned into WARN_ON(!file) Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25introduce __fcheck_files() to fix rcu_dereference_check_fdtable(), kill ↵Oleg Nesterov1-2/+2
rcu_my_thread_group_empty() rcu_dereference_check_fdtable() looks very wrong, 1. rcu_my_thread_group_empty() was added by 844b9a8707f1 "vfs: fix RCU-lockdep false positive due to /proc" but it doesn't really fix the problem. A CLONE_THREAD (without CLONE_FILES) task can hit the same race with get_files_struct(). And otoh rcu_my_thread_group_empty() can suppress the correct warning if the caller is the CLONE_FILES (without CLONE_THREAD) task. 2. files->count == 1 check is not really right too. Even if this files_struct is not shared it is not safe to access it lockless unless the caller is the owner. Otoh, this check is sub-optimal. files->count == 0 always means it is safe to use it lockless even if files != current->files, but put_files_struct() has to take rcu_read_lock(). See the next patch. This patch removes the buggy checks and turns fcheck_files() into __fcheck_files() which uses rcu_dereference_raw(), the "unshared" callers, fget_light() and fget_raw_light(), can use it to avoid the warning from RCU-lockdep. fcheck_files() is trivially reimplemented as rcu_lockdep_assert() plus __fcheck_files(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-02don't bother with deferred freeing of fdtablesAl Viro1-66/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-19locking: Various static lock initializer fixesThomas Gleixner1-1/+1
The static lock initializers want to be fed the proper name of the lock and not some random string. In mainline random strings are obfuscating the readability of debug output, but for RT they prevent the spinlock substitution. Fix it up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-01-04misc: remove __dev* attributes.Greg Kroah-Hartman1-1/+1
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the last of the __dev* markings from the kernel from a variety of different, tiny, places. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-13Merge branch 'for-linus' of ↵Linus Torvalds1-6/+0
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull big execve/kernel_thread/fork unification series from Al Viro: "All architectures are converted to new model. Quite a bit of that stuff is actually shared with architecture trees; in such cases it's literally shared branch pulled by both, not a cherry-pick. A lot of ugliness and black magic is gone (-3KLoC total in this one): - kernel_thread()/kernel_execve()/sys_execve() redesign. We don't do syscalls from kernel anymore for either kernel_thread() or kernel_execve(): kernel_thread() is essentially clone(2) with callback run before we return to userland, the callbacks either never return or do successful do_execve() before returning. kernel_execve() is a wrapper for do_execve() - it doesn't need to do transition to user mode anymore. As a result kernel_thread() and kernel_execve() are arch-independent now - they live in kernel/fork.c and fs/exec.c resp. sys_execve() is also in fs/exec.c and it's completely architecture-independent. - daemonize() is gone, along with its parts in fs/*.c - struct pt_regs * is no longer passed to do_fork/copy_process/ copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump. - sys_fork()/sys_vfork()/sys_clone() unified; some architectures still need wrappers (ones with callee-saved registers not saved in pt_regs on syscall entry), but the main part of those suckers is in kernel/fork.c now." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits) do_coredump(): get rid of pt_regs argument print_fatal_signal(): get rid of pt_regs argument ptrace_signal(): get rid of unused arguments get rid of ptrace_signal_deliver() arguments new helper: signal_pt_regs() unify default ptrace_signal_deliver flagday: kill pt_regs argument of do_fork() death to idle_regs() don't pass regs to copy_process() flagday: don't pass regs to copy_thread() bfin: switch to generic vfork, get rid of pointless wrappers xtensa: switch to generic clone() openrisc: switch to use of generic fork and clone unicore32: switch to generic clone(2) score: switch to generic fork/vfork/clone c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone() take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h mn10300: switch to generic fork/vfork/clone h8300: switch to generic fork/vfork/clone tile: switch to generic clone() ... Conflicts: arch/microblaze/include/asm/Kbuild
2012-11-30fix off-by-one in argument passed by iterate_fd() to callbacksAl Viro1-6/+8
Noticed by Pavel Roskin; the thing in his patch I disagree with was compensating for that shite in callbacks instead of fixing it once in the iterator itself. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-29kill daemonize()Al Viro1-6/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-18Merge branch 'for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc VFS fixes from Al Viro: "Remove a bogus BUG_ON() that can trigger spuriously + alpha bits of do_mount() constification I'd missed during the merge window." This pull request came in a week ago, I missed it for some reason. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kill bogus BUG_ON() in do_close_on_exec() missing const in alpha callers of do_mount()
2012-11-12kill bogus BUG_ON() in do_close_on_exec()Al Viro1-1/+0
It can be legitimately triggered via procfs access. Now, at least 2 of 3 of get_files_struct() callers in procfs are useless, but when and if we get rid of those we can always add WARN_ON() here. BUG_ON() at that spot is simply wrong. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-31Return the right error value when dup[23]() newfd argument is too largeAl Viro1-2/+2
Jack Lin reports that the error return from dup3() for the RLIMIT_NOFILE case changed incorrectly after 3.6. The culprit is commit f33ff9927f42 ("take rlimit check to callers of expand_files()") which when it moved the "return -EMFILE" out to the caller, didn't notice that the dup3() had special code to turn the EMFILE return into EBADF. The replace_fd() helper that got added later then inherited the bug too. Reported-by: Jack Lin <linliangjie@huawei.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [ Noted more bugs, wrote proper changelog, fixed up typos - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-10dup3: Return an error when oldfd == newfd.Richard W.M. Jones1-0/+3
I have tested the attached patch to fix the dup3 regression. Rich. From 0944e30e12dec6544b3602626b60ff412375c78f Mon Sep 17 00:00:00 2001 From: "Richard W.M. Jones" <rjones@redhat.com> Date: Tue, 9 Oct 2012 14:42:45 +0100 Subject: [PATCH] dup3: Return an error when oldfd == newfd. The following commit: commit fe17f22d7fd0e344ef6447238f799bb49f670c6f Author: Al Viro <viro@zeniv.linux.org.uk> Date: Tue Aug 21 11:48:11 2012 -0400 take purely descriptor-related stuff from fcntl.c to file.c was supposed to be just code motion, but it dropped the following two lines: if (unlikely(oldfd == newfd)) return -EINVAL; from the dup3 system call. dup3 is not specified by POSIX, so Linux can do what it likes. However the POSIX proposal for dup3 [1] states that it should return an error if oldfd == newfd. [1] http://austingroupbugs.net/view.php?id=411 Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27export fget_lightAl Viro1-0/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27new helper: daemonize_descriptors()Al Viro1-0/+6
descriptor-related parts of daemonize, done right. As the result we simplify the locking rules for ->files - we hold task_lock in *all* cases when we modify ->files. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27new helper: iterate_fd()Al Viro1-0/+21
iterates through the opened files in given descriptor table, calling a supplied function; we stop once non-zero is returned. Callback gets struct file *, descriptor number and const void * argument passed to iterator. It is called with files->file_lock held, so it is not allowed to block. tty_io, netprio_cgroup and selinux flush_unauthorized_files() converted to its use. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27make expand_files() and alloc_fd() staticAl Viro1-2/+2
no callers outside of fs/file.c left Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27take __{set,clear}_{open_fd,close_on_exec}() into fs/file.cAl Viro1-0/+20
nobody uses those outside anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27new helper: replace_fd()Al Viro1-29/+62
analog of dup2(), except that it takes struct file * as source. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27take purely descriptor-related stuff from fcntl.c to file.cAl Viro1-0/+132
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27take close-on-exec logics to fs/file.c, clean it up a bitAl Viro1-0/+37
... and add cond_resched() there, while we are at it. We can get large latencies as is... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27take descriptor-related part of close() to file.cAl Viro1-0/+26
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27take fget() and friends to fs/file.cAl Viro1-0/+106
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27expose a low-level variant of fd_install() for binderAl Viro1-2/+14
Similar situation to that of __alloc_fd(); do not use unless you really have to. You should not touch any descriptor table other than your own; it's a sure sign of a really bad API design. As with __alloc_fd(), you *must* use a first-class reference to struct files_struct; something obtained by get_files_struct(some task) (let alone direct task->files) will not do. It must be either current->files, or obtained by get_files_struct(current) by the owner of that sucker and given to you. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27move put_unused_fd() and fd_install() to fs/file.cAl Viro1-0/+44
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27trim free_fdtable_rcu()Al Viro1-15/+2
embedded case isn't hit anymore Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27don't bother with call_rcu() in put_files_struct()Al Viro1-9/+5
At that point nobody can see us anyway; everything that looks at files_fdtable(files) is separated from the guts of put_files_struct(files) - either since files is current->files or because we fetched it under task_lock() and hadn't dropped that yet, or because we'd bumped files->count while holding task_lock()... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27move files_struct-related bits from kernel/exit.c to fs/file.cAl Viro1-1/+99
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27new helper: __alloc_fd()Al Viro1-4/+8
Essentially, alloc_fd() in a files_struct we own a reference to. Most of the time wanting to use it is a sign of lousy API design (such as android/binder). It's *not* a general-purpose interface; better that than open-coding its guts, but again, playing with other process' descriptor table is a sign of bad design. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27take rlimit check to callers of expand_files()Al Viro1-7/+9
... except for one in android, where the check is different and already done in caller. No need to recalculate rlimit many times in alloc_fd() either. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-27make get_unused_fd_flags() a functionAl Viro1-3/+3
... and get_unused_fd() a macro around it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-30Merge branch 'x86-x32-for-linus' of ↵Linus Torvalds1-27/+25
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x32 support for x86-64 from Ingo Molnar: "This tree introduces the X32 binary format and execution mode for x86: 32-bit data space binaries using 64-bit instructions and 64-bit kernel syscalls. This allows applications whose working set fits into a 32 bits address space to make use of 64-bit instructions while using a 32-bit address space with shorter pointers, more compressed data structures, etc." Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c} * 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) x32: Fix alignment fail in struct compat_siginfo x32: Fix stupid ia32/x32 inversion in the siginfo format x32: Add ptrace for x32 x32: Switch to a 64-bit clock_t x32: Provide separate is_ia32_task() and is_x32_task() predicates x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls x86/x32: Fix the binutils auto-detect x32: Warn and disable rather than error if binutils too old x32: Only clear TIF_X32 flag once x32: Make sure TS_COMPAT is cleared for x32 tasks fs: Remove missed ->fds_bits from cessation use of fd_set structs internally fs: Fix close_on_exec pointer in alloc_fdtable x32: Drop non-__vdso weak symbols from the x32 VDSO x32: Fix coding style violations in the x32 VDSO code x32: Add x32 VDSO support x32: Allow x32 to be configured x32: If configured, add x32 system calls to system call tables x32: Handle process creation x32: Signal-related system calls x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h> ...
2012-02-29fs: reduce the use of module.h wherever possiblePaul Gortmaker1-1/+1
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24fs: Fix close_on_exec pointer in alloc_fdtableBobby Powers1-1/+1
alloc_fdtable allocates space for the open_fds and close_on_exec bitfields together, as 2 * nr / BITS_PER_BYTE. close_on_exec needs to point to open_fds + nr / BITS_PER_BYTE, not open_fds + nr / BITS_PER_LONG, as introducted in 1fd36adc: Replace the fd_sets in struct fdtable with an array of unsigned longs. Signed-off-by: Bobby Powers <bobbypowers@gmail.com> Link: http://lkml.kernel.org/r/1329888587-3087-1-git-send-email-bobbypowers@gmail.com Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-02-19Replace the fd_sets in struct fdtable with an array of unsigned longsDavid Howells1-24/+22
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 <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20120216174954.23314.48147.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk>
2012-02-19Wrap accesses to the fd_sets in struct fdtableDavid Howells1-4/+4
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 <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk>
2011-04-28vfs: avoid large kmalloc()s for the fdtableAndrew Morton1-7/+11
Azurit reports large increases in system time after 2.6.36 when running Apache. It was bisected down to a892e2d7dcdfa6c76e6 ("vfs: use kmalloc() to allocate fdmem if possible"). That patch caused the vfs to use kmalloc() for very large allocations and this is causing excessive work (and presumably excessive reclaim) within the page allocator. Fix it by falling back to vmalloc() earlier - when the allocation attempt would have been considered "costly" by reclaim. Reported-by: azurIt <azurit@pobox.sk> Tested-by: azurIt <azurit@pobox.sk> Acked-by: Changli Gao <xiaosuo@gmail.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11vfs: use kmalloc() to allocate fdmem if possibleChangli Gao1-34/+23
Use kmalloc() to allocate fdmem if possible. vmalloc() is used as a fallback solution for fdmem allocation. A new helper function __free_fdtable() is introduced to reduce the lines of code. A potential bug, vfree() a memory allocated by kmalloc(), is fixed. [akpm@linux-foundation.org: use __GFP_NOWARN, uninline alloc_fdmem() and free_fdmem()] Signed-off-by: Changli Gao <xiaosuo@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Avi Kivity <avi@redhat.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-15fs: remove all rcu head initializations, except on_stack initializationsPaul E. McKenney1-3/+0
Remove all rcu head inits. We don't care about the RCU head state before passing it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can keep track of objects on stack. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andries Brouwer <aeb@cwi.nl>
2010-03-06fs: use rlimit helpersJiri Slaby1-1/+1
Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented. I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource: add helpers for fetching rlimits") or ACCESS_ONCE if not applicable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>