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* | fix off-by-one in argument passed by iterate_fd() to callbacksAl Viro2012-11-291-6/+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>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-11-181-1/+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()
| * kill bogus BUG_ON() in do_close_on_exec()Al Viro2012-11-121-1/+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>
* | Return the right error value when dup[23]() newfd argument is too largeAl Viro2012-10-301-2/+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>
* dup3: Return an error when oldfd == newfd.Richard W.M. Jones2012-10-091-0/+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>
* export fget_lightAl Viro2012-09-261-0/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: daemonize_descriptors()Al Viro2012-09-261-0/+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>
* new helper: iterate_fd()Al Viro2012-09-261-0/+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>
* make expand_files() and alloc_fd() staticAl Viro2012-09-261-2/+2
| | | | | | no callers outside of fs/file.c left Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take __{set,clear}_{open_fd,close_on_exec}() into fs/file.cAl Viro2012-09-261-0/+20
| | | | | | nobody uses those outside anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: replace_fd()Al Viro2012-09-261-29/+62
| | | | | | analog of dup2(), except that it takes struct file * as source. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take purely descriptor-related stuff from fcntl.c to file.cAl Viro2012-09-261-0/+132
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take close-on-exec logics to fs/file.c, clean it up a bitAl Viro2012-09-261-0/+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>
* take descriptor-related part of close() to file.cAl Viro2012-09-261-0/+26
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take fget() and friends to fs/file.cAl Viro2012-09-261-0/+106
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* expose a low-level variant of fd_install() for binderAl Viro2012-09-261-2/+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>
* move put_unused_fd() and fd_install() to fs/file.cAl Viro2012-09-261-0/+44
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* trim free_fdtable_rcu()Al Viro2012-09-261-15/+2
| | | | | | embedded case isn't hit anymore Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't bother with call_rcu() in put_files_struct()Al Viro2012-09-261-9/+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>
* move files_struct-related bits from kernel/exit.c to fs/file.cAl Viro2012-09-261-1/+99
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: __alloc_fd()Al Viro2012-09-261-4/+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>
* take rlimit check to callers of expand_files()Al Viro2012-09-261-7/+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>
* make get_unused_fd_flags() a functionAl Viro2012-09-261-3/+3
| | | | | | ... and get_unused_fd() a macro around it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'x86-x32-for-linus' of ↵Linus Torvalds2012-03-291-27/+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> ...
| * fs: Fix close_on_exec pointer in alloc_fdtableBobby Powers2012-02-231-1/+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>
| * Replace the fd_sets in struct fdtable with an array of unsigned longsDavid Howells2012-02-191-24/+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>
| * Wrap accesses to the fd_sets in struct fdtableDavid Howells2012-02-191-4/+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>
* | fs: reduce the use of module.h wherever possiblePaul Gortmaker2012-02-281-1/+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>
* vfs: avoid large kmalloc()s for the fdtableAndrew Morton2011-04-281-7/+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>
* vfs: use kmalloc() to allocate fdmem if possibleChangli Gao2010-08-111-34/+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>
* fs: remove all rcu head initializations, except on_stack initializationsPaul E. McKenney2010-06-141-3/+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>
* fs: use rlimit helpersJiri Slaby2010-03-061-1/+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>
* vfs: Apply lockdep-based checking to rcu_dereference() usesPaul E. McKenney2010-02-251-1/+1
| | | | | | | | | | | | | | | | | | | | | Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable() and fcheck_files(). Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> 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 <viro@zeniv.linux.org.uk> LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* headers: remove sched.h from interrupt.hAlexey Dobriyan2009-10-111-0/+1
| | | | | | | | After m68k's task_thread_info() doesn't refer to current, it's possible to remove sched.h from interrupt.h and not break m68k! Many thanks to Heiko Carstens for allowing this. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* [PATCH] merge locate_fd() and get_unused_fd()Al Viro2008-08-011-0/+61
| | | | | | | New primitive: alloc_fd(start, flags). get_unused_fd() and get_unused_fd_flags() become wrappers on top of it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] fix RLIM_NOFILE handlingAl Viro2008-07-261-0/+9
| | | | | | | | | | | | * dup2() should return -EBADF on exceeded sysctl_nr_open * dup() should *not* return -EINVAL even if you have rlimit set to 0; it should get -EMFILE instead. Check for orig_start exceeding rlimit taken to sys_fcntl(). Failing expand_files() in dup{2,3}() now gets -EMFILE remapped to -EBADF. Consequently, remaining checks for rlimit are taken to expand_files(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] avoid multiplication overflows and signedness issues for max_fdsAl Viro2008-05-161-0/+4
| | | | | | | Limit sysctl_nr_open - we don't want ->max_fds to exceed MAX_INT and we don't want size calculation for ->fd[] to overflow. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] dup_fd() part 4 - race fixAl Viro2008-05-161-2/+8
| | | | | | | | | | | | | | | | | Parent _can_ be a clone task, contrary to the comment. Moreover, more files could be opened while we allocate a copy, in which case we end up copying only part into new descriptor table. Since what we get _is_ affected by all changes in the old range, we can get rather weird effects - e.g. dup2(0, 1024); close(0); in parallel with fork() resulting in child that sees the effect of close(), but not that of dup2() done just before that close(). What we need is to recalculate the open_count after having reacquired ->file_lock and if external fdtable we'd just allocated is too small for it, free the sucker and redo allocation. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] dup_fd() - part 3Al Viro2008-05-161-28/+15
| | | | | | merge alloc_files() into dup_fd(), leave setting newf->fdt until the end Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] dup_fd() part 2Al Viro2008-05-161-8/+16
| | | | | | | | use alloc_fdtable() instead of expand_files(), get rid of pointless grabbing newf->file_lock, kill magic in copy_fdtable() that used to be there only to skip copying when called from dup_fd(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] dup_fd() fixes, part 1Al Viro2008-05-161-0/+130
| | | | | | Move the sucker to fs/file.c in preparation to the rest Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] take init_files to fs/file.cAl Viro2008-05-161-0/+13
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] fix sysctl_nr_open bugsAl Viro2008-05-011-2/+20
| | | | | | | | | * if luser with root sets it to something that is not a multiple of BITS_PER_LONG, the system is screwed. * if it gets decreased at the wrong time, we can get expand_files() returning success and _not_ increasing the size of table as asked. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] split linux/file.hAl Viro2008-05-011-0/+1
| | | | | | Initial splitoff of the low-level stuff; taken to fdtable.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* get rid of NR_OPEN and introduce a sysctl_nr_openEric Dumazet2008-02-061-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | NR_OPEN (historically set to 1024*1024) actually forbids processes to open more than 1024*1024 handles. Unfortunatly some production servers hit the not so 'ridiculously high value' of 1024*1024 file descriptors per process. Changing NR_OPEN is not considered safe because of vmalloc space potential exhaust. This patch introduces a new sysctl (/proc/sys/fs/nr_open) wich defaults to 1024*1024, so that admins can decide to change this limit if their workload needs it. [akpm@linux-foundation.org: export it for sparc64] Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] fdtable: Provide free_fdtable() wrapperVadim Lobanov2006-12-221-1/+1
| | | | | | | | | | | | | | Christoph Hellwig has expressed concerns that the recent fdtable changes expose the details of the RCU methodology used to release no-longer-used fdtable structures to the rest of the kernel. The trivial patch below addresses these concerns by introducing the appropriate free_fdtable() calls, which simply wrap the release RCU usage. Since free_fdtable() is a one-liner, it makes sense to promote it to an inline helper. Signed-off-by: Vadim Lobanov <vlobanov@speakeasy.net> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fdtable: Implement new pagesize-based fdtable allocatorVadim Lobanov2006-12-101-136/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch provides an improved fdtable allocation scheme, useful for expanding fdtable file descriptor entries. The main focus is on the fdarray, as its memory usage grows 128 times faster than that of an fdset. The allocation algorithm sizes the fdarray in such a way that its memory usage increases in easy page-sized chunks. The overall algorithm expands the allowed size in powers of two, in order to amortize the cost of invoking vmalloc() for larger allocation sizes. Namely, the following sizes for the fdarray are considered, and the smallest that accommodates the requested fd count is chosen: pagesize / 4 pagesize / 2 pagesize <- memory allocator switch point pagesize * 2 pagesize * 4 ...etc... Unlike the current implementation, this allocation scheme does not require a loop to compute the optimal fdarray size, and can be done in efficient straightline code. Furthermore, since the fdarray overflows the pagesize boundary long before any of the fdsets do, it makes sense to optimize run-time by allocating both fdsets in a single swoop. Even together, they will still be, by far, smaller than the fdarray. The fdtable->open_fds is now used as the anchor for the fdset memory allocation. Signed-off-by: Vadim Lobanov <vlobanov@speakeasy.net> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fdtable: Remove the free_files fieldVadim Lobanov2006-12-101-19/+8
| | | | | | | | | | | | | | | | | | | An fdtable can either be embedded inside a files_struct or standalone (after being expanded). When an fdtable is being discarded after all RCU references to it have expired, we must either free it directly, in the standalone case, or free the files_struct it is contained within, in the embedded case. Currently the free_files field controls this behavior, but we can get rid of it entirely, as all the necessary information is already recorded. We can distinguish embedded and standalone fdtables using max_fds, and if it is embedded we can divine the relevant files_struct using container_of(). Signed-off-by: Vadim Lobanov <vlobanov@speakeasy.net> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fdtable: Make fdarray and fdsets equal in sizeVadim Lobanov2006-12-101-34/+22
| | | | | | | | | | | | | | | | | | | | | | | | Currently, each fdtable supports three dynamically-sized arrays of data: the fdarray and two fdsets. The code allows the number of fds supported by the fdarray (fdtable->max_fds) to differ from the number of fds supported by each of the fdsets (fdtable->max_fdset). In practice, it is wasteful for these two sizes to differ: whenever we hit a limit on the smaller-capacity structure, we will reallocate the entire fdtable and all the dynamic arrays within it, so any delta in the memory used by the larger-capacity structure will never be touched at all. Rather than hogging this excess, we shouldn't even allocate it in the first place, and keep the capacities of the fdarray and the fdsets equal. This patch removes fdtable->max_fdset. As an added bonus, most of the supporting code becomes simpler. Signed-off-by: Vadim Lobanov <vlobanov@speakeasy.net> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] file: kill unnecessary timer in fdtable_deferTejun Heo2006-12-071-27/+2
| | | | | | | | | | | | | | | | | | free_fdtable_rc() schedules timer to reschedule fddef->wq if schedule_work() on it returns 0. However, schedule_work() guarantees that the target work is executed at least once after the scheduling regardless of its return value. 0 return simply means that the work was already pending and thus no further action was required. Another problem is that it used contant '5' as @expires argument to mod_timer(). Kill unnecessary fddef->timer. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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