Change the atomic_t in struct nfs_server to atomic_long_t in anticipation
of machines that can handle 8+TB of (4K) pages under writeback.
However I suspect other things in NFS will start going *bang* by then.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement utimensat(2) which is an extension to futimesat(2) in that it
a) supports nano-second resolution for the timestamps
b) allows to selectively ignore the atime/mtime value
c) allows to selectively use the current time for either atime or mtime
d) supports changing the atime/mtime of a symlink itself along the lines
of the BSD lutimes(3) functions
For this change the internally used do_utimes() functions was changed to
accept a timespec time value and an additional flags parameter.
Additionally the sys_utime function was changed to match compat_sys_utime
which already use do_utimes instead of duplicating the work.
Also, the completely missing futimensat() functionality is added. We have
such a function in glibc but we have to resort to using /proc/self/fd/* which
not everybody likes (chroot etc).
Test application (the syscall number will need per-arch editing):
#include <errno.h>
#include <fcntl.h>
#include <time.h>
#include <sys/time.h>
#include <stddef.h>
#include <syscall.h>
#define __NR_utimensat 280
#define UTIME_NOW ((1l << 30) - 1l)
#define UTIME_OMIT ((1l << 30) - 2l)
int
main(void)
{
int status = 0;
int fd = open("ttt", O_RDWR|O_CREAT|O_EXCL, 0666);
if (fd == -1)
error (1, errno, "failed to create test file \"ttt\"");
struct stat64 st1;
if (fstat64 (fd, &st1) != 0)
error (1, errno, "fstat failed");
struct timespec t[2];
t[0].tv_sec = 0;
t[0].tv_nsec = 0;
t[1].tv_sec = 0;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
struct stat64 st2;
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0)
{
puts ("atim not reset to zero");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim not reset to zero");
status = 1;
}
if (status != 0)
goto out;
t[0] = st1.st_atim;
t[1].tv_sec = 0;
t[1].tv_nsec = UTIME_OMIT;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != st1.st_atim.tv_sec
|| st2.st_atim.tv_nsec != st1.st_atim.tv_nsec)
{
puts ("atim not set");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim changed from zero");
status = 1;
}
if (status != 0)
goto out;
t[0].tv_sec = 0;
t[0].tv_nsec = UTIME_OMIT;
t[1] = st1.st_mtim;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != st1.st_atim.tv_sec
|| st2.st_atim.tv_nsec != st1.st_atim.tv_nsec)
{
puts ("mtim changed from original time");
status = 1;
}
if (st2.st_mtim.tv_sec != st1.st_mtim.tv_sec
|| st2.st_mtim.tv_nsec != st1.st_mtim.tv_nsec)
{
puts ("mtim not set");
status = 1;
}
if (status != 0)
goto out;
sleep (2);
t[0].tv_sec = 0;
t[0].tv_nsec = UTIME_NOW;
t[1].tv_sec = 0;
t[1].tv_nsec = UTIME_NOW;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
struct timeval tv;
gettimeofday(&tv,NULL);
if (st2.st_atim.tv_sec <= st1.st_atim.tv_sec
|| st2.st_atim.tv_sec > tv.tv_sec)
{
puts ("atim not set to NOW");
status = 1;
}
if (st2.st_mtim.tv_sec <= st1.st_mtim.tv_sec
|| st2.st_mtim.tv_sec > tv.tv_sec)
{
puts ("mtim not set to NOW");
status = 1;
}
if (symlink ("ttt", "tttsym") != 0)
error (1, errno, "cannot create symlink");
t[0].tv_sec = 0;
t[0].tv_nsec = 0;
t[1].tv_sec = 0;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, AT_FDCWD, "tttsym", t, AT_SYMLINK_NOFOLLOW) != 0)
error (1, errno, "utimensat failed");
if (lstat64 ("tttsym", &st2) != 0)
error (1, errno, "lstat failed");
if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0)
{
puts ("symlink atim not reset to zero");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("symlink mtim not reset to zero");
status = 1;
}
if (status != 0)
goto out;
t[0].tv_sec = 1;
t[0].tv_nsec = 0;
t[1].tv_sec = 1;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, fd, NULL, t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != 1 || st2.st_atim.tv_nsec != 0)
{
puts ("atim not reset to one");
status = 1;
}
if (st2.st_mtim.tv_sec != 1 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim not reset to one");
status = 1;
}
if (status == 0)
puts ("all OK");
out:
close (fd);
unlink ("ttt");
unlink ("tttsym");
return status;
}
[akpm@linux-foundation.org: add missing i386 syscall table entry]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes it so that simple_fill_super and get_sb_pseudo assign their
root inodes to be number 1. It also fixes up a couple of callers of
simple_fill_super that were passing in files arrays that had an index at
number 1, and adds a warning for any caller that sends in such an array.
It would have been nice to have made it so that it wasn't possible to make
such a collision, but some callers need to be able to control what inode
number their entries get, so I think this is the best that can be done.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
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>
The problems are:
- on filesystems w/o permanent inode numbers, i_ino values can be larger
than 32 bits, which can cause problems for some 32 bit userspace programs on
a 64 bit kernel. We can't do anything for filesystems that have actual
>32-bit inode numbers, but on filesystems that generate i_ino values on the
fly, we should try to have them fit in 32 bits. We could trivially fix this
by making the static counters in new_inode and iunique 32 bits, but...
- many filesystems call new_inode and assume that the i_ino values they are
given are unique. They are not guaranteed to be so, since the static
counter can wrap. This problem is exacerbated by the fix for #1.
- after allocating a new inode, some filesystems call iunique to try to get
a unique i_ino value, but they don't actually add their inodes to the
hashtable, and so they're still not guaranteed to be unique if that counter
wraps.
This patch set takes the simpler approach of simply using iunique and hashing
the inodes afterward. Christoph H. previously mentioned that he thought that
this approach may slow down lookups for filesystems that currently hash their
inodes.
The questions are:
1) how much would this slow down lookups for these filesystems?
2) is it enough to justify adding more infrastructure to avoid it?
What might be best is to start with this approach and then only move to using
IDR or some other scheme if these extra inodes in the hashtable prove to be
problematic.
I've done some cursory testing with this patch and the overhead of hashing and
unhashing the inodes with pipefs is pretty low -- just a few seconds of system
time added on to the creation and destruction of 10 million pipes (very
similar to the overhead that the IDR approach would add).
The hard thing to measure is what effect this has on other filesystems. I'm
open to ways to try and gauge this.
Again, I've only converted pipefs as an example. If this approach is
acceptable then I'll start work on patches to convert other filesystems.
With a pretty-much-worst-case microbenchmark provided by Eric Dumazet
<dada1@cosmosbay.com>:
hashing patch (pipebench):
sys 1m15.329s
sys 1m16.249s
sys 1m17.169s
unpatched (pipebench):
sys 1m9.836s
sys 1m12.541s
sys 1m14.153s
Which works out to 1.05642174294555027017. So ~5-6% slowdown.
This patch:
When a 32-bit program that was not compiled with large file offsets does a
stat and gets a st_ino value back that won't fit in the 32 bit field, glibc
(correctly) generates an EOVERFLOW error. We can't do anything about fs's
with larger permanent inode numbers, but when we generate them on the fly, we
ought to try and have them fit within a 32 bit field.
This patch takes the first step toward this by making the static counters in
these two functions be 32 bits.
[jlayton@redhat.com: mention that it's only the case for 32bit, non-LFS stat]
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
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>
When elf loader fails to map executable (due to memory shortage or because
binary is malformed), it can return 0. Normally, this is invisible because
process is killed with SIGKILL and it never returns to user space.
But if exec() is called from kernel thread (hotplug, whatever)
consequences are more interesting and vary depending on architecture.
i386. Nothing especially interesting, execve() just returns
with "success" :-)
x86_64. Fake zero frame is used on way to caller, RSP/RIP are loaded
with zeros, ergo... double fault.
ia64. Similar to i386, but r32...r95 are corrupted. Sometimes it
oopses due to return to zero PC, sometimes it sees NaT in
rXX and oopses due to NaT consumption.
Signed-off-by: Alexey Kuznetsov <alexey@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup using simple_read_from_buffer() in procfs.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It appears that a minor thinko occurred in udf_rmdir and the
(already-cleared) link count on the directory that is being removed was
being decremented instead of the link count on its parent directory. This
gives rise to lots of kernel messages similar to:
UDF-fs warning (device loop1): udf_rmdir: empty directory has nlink != 2 (8)
when removing directory trees. No other ill effects have been observed but
I guess it could theoretically result in the link count overflowing on a
very long-lived, much modified directory.
Signed-off-by: Stephen Mollett <molletts@yahoo.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you compile and run the below test case in an msdos or vfat directory on
an x86-64 system with -m32 you'll get garbage in the kernel_dirent struct
followed by a SIGSEGV.
The patch fixes this.
Reported and initial fix by Bart Oldeman
#include <sys/types.h>
#include <sys/ioctl.h>
#include <dirent.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
struct kernel_dirent {
long d_ino;
long d_off;
unsigned short d_reclen;
char d_name[256]; /* We must not include limits.h! */
};
#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct kernel_dirent [2])
#define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct kernel_dirent [2])
int main(void)
{
int fd = open(".", O_RDONLY);
struct kernel_dirent de[2];
while (1) {
int i = ioctl(fd, VFAT_IOCTL_READDIR_BOTH, (long)de);
if (i == -1) break;
if (de[0].d_reclen == 0) break;
printf("SFN: reclen=%2d off=%d ino=%d, %-12s",
de[0].d_reclen, de[0].d_off, de[0].d_ino, de[0].d_name);
if (de[1].d_reclen)
printf("\tLFN: reclen=%2d off=%d ino=%d, %s",
de[1].d_reclen, de[1].d_off, de[1].d_ino, de[1].d_name);
printf("\n");
}
return 0;
}
Signed-off-by: Bart Oldeman <bartoldeman@users.sourceforge.net>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Propagate flags such as S_APPEND, S_IMMUTABLE, etc. from i_flags into
ext2-specific i_flags. Hence, when someone sets these flags via a different
interface than ioctl, they are stored correctly.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It seems that the recent Windows changed specification, and it's
undocumented. Windows doesn't update ->free_clusters correctly.
This patch doesn't use ->free_clusters by default. (instead, add "usefree"
for forcing to use it)
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Juergen Beisert <juergen127@kreuzholzen.de>
Cc: Andreas Schwab <schwab@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the thread failed to create the subsequent wait_event will hang forever.
This is likely to happen if kernel hits max_threads limit.
Will be critical for virtualization systems that limit the number of tasks
and kernel memory usage within the container.
(akpm: JBD should be converted fully to the kthread API: kthread_should_stop()
and kthread_stop()).
Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a missing check for CAP_SYS_ADMIN in do_change_type().
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A patch that stores inode flags such as S_IMMUTABLE, S_APPEND, etc. from
i_flags to EXT3_I(inode)->i_flags when inode is written to disk. The same
thing is done on GETFLAGS ioctl.
Quota code changes these flags on quota files (to make it harder for
sysadmin to screw himself) and these changes were not correctly propagated
into the filesystem (especially, lsattr did not show them and users were
wondering...).
Propagate flags such as S_APPEND, S_IMMUTABLE, etc. from i_flags into
ext3-specific i_flags. Hence, when someone sets these flags via a
different interface than ioctl, they are stored correctly.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are many places in the kernel where the construction like
foo = list_entry(head->next, struct foo_struct, list);
are used.
The code might look more descriptive and neat if using the macro
list_first_entry(head, type, member) \
list_entry((head)->next, type, member)
Here is the macro itself and the examples of its usage in the generic code.
If it will turn out to be useful, I can prepare the set of patches to
inject in into arch-specific code, drivers, networking, etc.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A while back, Christoph mentioned that he thought that iunique ought to be
cleaned up to use a more conventional loop construct. This patch does that,
turning the strange goto loop into a do/while.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
notify_change() already calls security_inode_setattr() before
calling iop->setattr.
Alan sayeth
This is a behaviour change on all of these and limits some behaviour of
existing established security modules
When inode_change_ok is called it has side effects. This includes
clearing the SGID bit on attribute changes caused by chmod. If you make
this change the results of some rulesets may be different before or after
the change is made.
I'm not saying the change is wrong but it does change behaviour so that
needs looking at closely (ditto all other attribute twiddles)
Signed-off-by: Steve Beattie <sbeattie@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: John Johansen <jjohansen@suse.de>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
notify_change() already calls security_inode_setattr() before
calling iop->setattr.
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: John Johansen <jjohansen@suse.de>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can save some lines of code by using seq_release_private().
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge all compat ioctl handling into compat_ioctl.c instead of splitting it
over compat.c and compat_ioctl.c. This also allows to get rid of ioctl32.h
Signed-off-by: Christoph Hellwig <hch@lst.de>
Looks-good-to: Andi Kleen <ak@suse.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for the Motorola sysv68 disk partition (slices in motorola
doc).
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that there is no arch-specific compat ioctl handling left there is not
point in having a separate copat_ioctl.h, so merge it into compat_ioctl.c
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
linux/module.h
-> linux/elf.h
-> asm-i386/elf.h
-> linux/utsname.h
-> linux/sched.h
Noticeably cut the number of files which are rebuild upon touching sched.h
and cut down pulled junk from every module.h inclusion.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kallsyms_lookup() can go iterating over modules list unprotected which is OK
for emergency situations (oops), but not OK for regular stuff like
/proc/*/wchan.
Introduce lookup_symbol_name()/lookup_module_symbol_name() which copy symbol
name into caller-supplied buffer or return -ERANGE. All copying is done with
module_mutex held, so...
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Several kallsyms_lookup() pass dummy arguments but only need, say, module's
name. Make kallsyms_lookup() accept NULLs where possible.
Also, makes picture clearer about what interfaces are needed for all symbol
resolving business.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a binary format is unregistered and re-registered, register_binfmt
fails with -EBUSY. The reason is that unregister_binfmt does not set
fmt->next to NULL, and seeing (fmt->next != NULL), register_binfmt fails
with -EBUSY.
One can find his way around by explicitly setting fmt->next to NULL after
unregistering, but that is kind of unclean (one should better be using only
the interfaces, and not the interal members, isn't it?)
Attached one-liner can fix it.
Signed-off-by: Kalash Nainwal <kalash.nainwal@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
remove_inode_dquot_ref() can now become static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
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>
Remove do_sync_file_range() and convert callers to just use
do_sync_mapping_range().
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
REISER_FS /proc option needs to depend on PROC_FS.
fs/reiserfs/procfs.c: In function 'show_super':
fs/reiserfs/procfs.c:134: error: 'reiserfs_proc_info_data_t' has no member named 'max_hash_collisions'
fs/reiserfs/procfs.c:134: error: 'reiserfs_proc_info_data_t' has no member named 'breads'
fs/reiserfs/procfs.c:135: error: 'reiserfs_proc_info_data_t' has no member named 'bread_miss'
fs/reiserfs/procfs.c:135: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key'
fs/reiserfs/procfs.c:136: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key_fs_changed'
fs/reiserfs/procfs.c:136: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key_restarted'
fs/reiserfs/procfs.c:137: error: 'reiserfs_proc_info_data_t' has no member named 'insert_item_restarted'
fs/reiserfs/procfs.c:137: error: 'reiserfs_proc_info_data_t' has no member named 'paste_into_item_restarted'
fs/reiserfs/procfs.c:138: error: 'reiserfs_proc_info_data_t' has no member named 'cut_from_item_restarted'
fs/reiserfs/procfs.c:139: error: 'reiserfs_proc_info_data_t' has no member named 'delete_solid_item_restarted'
fs/reiserfs/procfs.c:139: error: 'reiserfs_proc_info_data_t' has no member named 'delete_item_restarted'
fs/reiserfs/procfs.c:140: error: 'reiserfs_proc_info_data_t' has no member named 'leaked_oid'
fs/reiserfs/procfs.c:140: error: 'reiserfs_proc_info_data_t' has no member named 'leaves_removable'
fs/reiserfs/procfs.c: In function 'show_per_level':
fs/reiserfs/procfs.c:184: error: 'reiserfs_proc_info_data_t' has no member named 'balance_at'
fs/reiserfs/procfs.c:185: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_read_at'
fs/reiserfs/procfs.c:186: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_fs_changed'
fs/reiserfs/procfs.c:187: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_restarted'
fs/reiserfs/procfs.c:188: error: 'reiserfs_proc_info_data_t' has no member named 'free_at'
fs/reiserfs/procfs.c:189: error: 'reiserfs_proc_info_data_t' has no member named 'items_at'
fs/reiserfs/procfs.c:190: error: 'reiserfs_proc_info_data_t' has no member named 'can_node_be_removed'
fs/reiserfs/procfs.c:191: error: 'reiserfs_proc_info_data_t' has no member named 'lnum'
fs/reiserfs/procfs.c:192: error: 'reiserfs_proc_info_data_t' has no member named 'rnum'
fs/reiserfs/procfs.c:193: error: 'reiserfs_proc_info_data_t' has no member named 'lbytes'
fs/reiserfs/procfs.c:194: error: 'reiserfs_proc_info_data_t' has no member named 'rbytes'
fs/reiserfs/procfs.c:195: error: 'reiserfs_proc_info_data_t' has no member named 'get_neighbors'
fs/reiserfs/procfs.c:196: error: 'reiserfs_proc_info_data_t' has no member named 'get_neighbors_restart'
fs/reiserfs/procfs.c:197: error: 'reiserfs_proc_info_data_t' has no member named 'need_l_neighbor'
fs/reiserfs/procfs.c:197: error: 'reiserfs_proc_info_data_t' has no member named 'need_r_neighbor'
fs/reiserfs/procfs.c: In function 'show_bitmap':
fs/reiserfs/procfs.c:224: error: 'reiserfs_proc_info_data_t' has no member named 'free_block'
fs/reiserfs/procfs.c:225: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:226: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:227: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:228: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:229: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:230: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:230: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c: In function 'show_journal':
fs/reiserfs/procfs.c:384: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:385: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:386: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:387: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:388: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:389: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:390: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:391: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:392: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:393: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:394: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c: In function 'reiserfs_proc_info_init':
fs/reiserfs/procfs.c:504: warning: implicit declaration of function '__PINFO'
fs/reiserfs/procfs.c:504: error: request for member 'lock' in something not a structure or union
fs/reiserfs/procfs.c: In function 'reiserfs_proc_info_done':
fs/reiserfs/procfs.c:544: error: request for member 'lock' in something not a structure or union
fs/reiserfs/procfs.c:545: error: request for member 'exiting' in something not a structure or union
fs/reiserfs/procfs.c:546: error: request for member 'lock' in something not a structure or union
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eternal quest to make
while true; do cat /proc/fs/xfs/stat >/dev/null 2>/dev/null; done
while true; do find /proc -type f 2>/dev/null | xargs cat >/dev/null 2>/dev/null; done
while true; do modprobe xfs; rmmod xfs; done
work reliably continues and now kernel oopses in the following way:
BUG: unable to handle ... at virtual address 6b6b6b6b
EIP is at badness
process: cat
proc_oom_score
proc_info_read
sys_fstat64
vfs_read
proc_info_read
sys_read
Failing code is prefetch hidden in list_for_each_entry() in badness().
badness() is reachable from two points. One is proc_oom_score, another
is out_of_memory() => select_bad_process() => badness().
Second path grabs tasklist_lock, while first doesn't.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1) Introduces a new method in 'struct dentry_operations'. This method
called d_dname() might be called from d_path() to build a pathname for
special filesystems. It is called without locks.
Future patches (if we succeed in having one common dentry for all
pipes/sockets) may need to change prototype of this method, but we now
use : char *d_dname(struct dentry *dentry, char *buffer, int buflen);
2) Adds a dynamic_dname() helper function that eases d_dname() implementations
3) Defines d_dname method for sockets : No more sprintf() at socket
creation. This is delayed up to the moment someone does an access to
/proc/pid/fd/...
4) Defines d_dname method for pipes : No more sprintf() at pipe
creation. This is delayed up to the moment someone does an access to
/proc/pid/fd/...
A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a
*nice* speedup on my Pentium(M) 1.6 Ghz :
3.090 s instead of 3.450 s
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for finding out the current file position, open flags and
possibly other info in the future.
These new entries are added:
/proc/PID/fdinfo/FD
/proc/PID/task/TID/fdinfo/FD
For each fd the information is provided in the following format:
pos: 1234
flags: 0100002
[bunk@stusta.de: make struct proc_fdinfo_file_operations static]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the order of fields of struct pid_entry (file fs/proc/base.c) in order
to avoid a hole on 64bit archs. (8 bytes saved per object)
Also change all pid_entry arrays to be const qualified, to make clear they
must not be modified.
Before (on x86_64) :
# size fs/proc/base.o
text data bss dec hex filename
15549 2192 0 17741 454d fs/proc/base.o
After :
# size fs/proc/base.o
text data bss dec hex filename
17229 176 0 17405 43fd fs/proc/base.o
Thats 336 bytes saved on kernel size on x86_64
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive
information about the memory location and usage of processes. Issues:
- maps should not be world-readable, especially if programs expect any
kind of ASLR protection from local attackers.
- maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc
check the maps when %n is in a *printf call, and a setuid(getuid())
process wouldn't be able to read its own maps file. (For reference
see http://lkml.org/lkml/2006/1/22/150)
- a system-wide toggle is needed to allow prior behavior in the case of
non-root applications that depend on access to the maps contents.
This change implements a check using "ptrace_may_attach" before allowing
access to read the maps contents. To control this protection, the new knob
/proc/sys/kernel/maps_protect has been added, with corresponding updates to
the procfs documentation.
[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: New sysctl numbers are old hat]
Signed-off-by: Kees Cook <kees@outflux.net>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't have a routine called namei() anymore since at least 2.3.x, and
the comment is just totally out of sync with the current lookup logic.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
inode->i_sb is always set, not need to check for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WARN_ON(de && de->deleted); is sooo unreliable. Why?
proc_lookup remove_proc_entry
=========== =================
lock_kernel();
spin_lock(&proc_subdir_lock);
[find proc entry]
spin_unlock(&proc_subdir_lock);
spin_lock(&proc_subdir_lock);
[find proc entry]
proc_get_inode
==============
WARN_ON(de && de->deleted); ...
if (!atomic_read(&de->count))
free_proc_entry(de);
else
de->deleted = 1;
So, if you have some strange oops [1], and doesn't see this WARN_ON it means
nothing.
[1] try_module_get() of module which doesn't exist, two lines below
should suffice, or not?
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a slight problem with filesystem type representation in fuse
based filesystems.
From the kernel's view, there are just two filesystem types: fuse and
fuseblk. From the user's view there are lots of different filesystem
types. The user is not even much concerned if the filesystem is fuse based
or not. So there's a conflict of interest in how this should be
represented in fstab, mtab and /proc/mounts.
The current scheme is to encode the real filesystem type in the mount
source. So an sshfs mount looks like this:
sshfs#user@server:/ /mnt/server fuse rw,nosuid,nodev,...
This url-ish syntax works OK for sshfs and similar filesystems. However
for block device based filesystems (ntfs-3g, zfs) it doesn't work, since
the kernel expects the mount source to be a real device name.
A possibly better scheme would be to encode the real type in the type
field as "type.subtype". So fuse mounts would look like this:
/dev/hda1 /mnt/windows fuseblk.ntfs-3g rw,...
user@server:/ /mnt/server fuse.sshfs rw,nosuid,nodev,...
This patch adds the necessary code to the kernel so that this can be
correctly displayed in /proc/mounts.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Epoll is doing multiple passes over the ready set at the moment, because of
the constraints over the f_op->poll() call. Looking at the code again, I
noticed that we already hold the epoll semaphore in read, and this
(together with other locking conditions that hold while doing an
epoll_wait()) can lead to a smarter way [1] to "ship" events to userspace
(in a single pass).
This is a stress application that can be used to test the new code. It
spwans multiple thread and call epoll_wait() and epoll_ctl() from many
threads. Stress tested on my dual Opteron 254 w/out any problems.
http://www.xmailserver.org/totalmess.c
This is not a benchmark, just something that tries to stress and exploit
possible problems with the new code.
Also, I made a stupid micro-benchmark:
http://www.xmailserver.org/epwbench.c
[1] Considering that epoll must be thread-safe, there are five ways we can
be hit during an epoll_wait() transfer loop (ep_send_events()):
1) The epoll fd going away and calling ep_free
This just can't happen, since we did an fget() in sys_epoll_wait
2) An epoll_ctl(EPOLL_CTL_DEL)
This can't happen because epoll_ctl() gets ep->sem in write, and
we're holding it in read during ep_send_events()
3) An fd stored inside the epoll fd going away
This can't happen because in eventpoll_release_file() we get
ep->sem in write, and we're holding it in read during
ep_send_events()
4) Another epoll_wait() happening on another thread
They both can be inside ep_send_events() at the same time, we get
(splice) the ready-list under the spinlock, so each one will get
its own ready list. Note that an fd cannot be at the same time
inside more than one ready list, because ep_poll_callback() will
not re-queue it if it sees it already linked:
if (ep_is_linked(&epi->rdllink))
goto is_linked;
Another case that can happen, is two concurrent epoll_wait(),
coming in with a userspace event buffer of size, say, ten.
Suppose there are 50 event ready in the list. The first
epoll_wait() will "steal" the whole list, while the second, seeing
no events, will go to sleep. But at the end of ep_send_events() in
the first epoll_wait(), we will re-inject surplus ready fds, and we
will trigger the proper wake_up to the second epoll_wait().
5) ep_poll_callback() hitting us asyncronously
This is the tricky part. As I said above, the ep_is_linked() test
done inside ep_poll_callback(), will guarantee us that until the
item will result linked to a list, ep_poll_callback() will not try
to re-queue it again (read, write data on any of its members). When
we do a list_del() in ep_send_events(), the item will still satisfy
the ep_is_linked() test (whatever data is written in prev/next,
it'll never be its own pointer), so ep_poll_callback() will still
leave us alone. It's only after the eventual smp_mb()+INIT_LIST_HEAD(&epi->rdllink)
that it'll become visible to ep_poll_callback(), but at the point
we're already past it.
[akpm@osdl.org: 80 cols]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- ext3_dx_find_entry() exit with out setting proper error pointer
- do_split() exit with out setting proper error pointer
it is realy painful because many callers contain folowing code:
de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
if (!(de))
return retval;
<<< WOW retval wasn't changed by do_split(), so caller failed
<<< but return SUCCESS :)
- Rearrange do_split() error path. Current error path is realy ugly, all
this up and down jump stuff doesn't make code easy to understand.
[dmonakhov@sw.ru: fix annoying fake error messages]
Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org>
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sys_clone() and sys_unshare() both makes copies of nsproxy and its associated
namespaces. But they have different code paths.
This patch merges all the nsproxy and its associated namespace copy/clone
handling (as much as possible). Posted on container list earlier for
feedback.
- Create a new nsproxy and its associated namespaces and pass it back to
caller to attach it to right process.
- Changed all copy_*_ns() routines to return a new copy of namespace
instead of attaching it to task->nsproxy.
- Moved the CAP_SYS_ADMIN checks out of copy_*_ns() routines.
- Removed unnessary !ns checks from copy_*_ns() and added BUG_ON()
just incase.
- Get rid of all individual unshare_*_ns() routines and make use of
copy_*_ns() instead.
[akpm@osdl.org: cleanups, warning fix]
[clg@fr.ibm.com: remove dup_namespaces() declaration]
[serue@us.ibm.com: fix CONFIG_IPC_NS=n, clone(CLONE_NEWIPC) retval]
[akpm@linux-foundation.org: fix build with CONFIG_SYSVIPC=n]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <containers@lists.osdl.org>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Tesarik discovered a problem in remove_arg_zero(). He writes:
When a script is loaded, load_script() replaces argv[0] with the
name of the interpreter and the filename passed to the exec syscall.
However, there is no guarantee that the length of the interpreter
name plus the length of the filename is greater than the length of
the original argv[0]. If the difference happens to cross a page boundary,
setup_arg_pages() will call put_dirty_page() [aka install_arg_page()]
with an address outside the VMA.
Therefore, remove_arg_zero() must free all pages which would be unused
after the argument is removed.
So, rewrite the remove_arg_zero function without gotos, with a few comments,
and with the commonly used explicit index/offset. This fixes the problem
and makes it easier to understand as well.
[a.p.zijlstra@chello.nl: add comment]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Correct the misspelling of the preprocessor check of a Kconfig option to refer
to CONFIG_REISERFS_PROC_INFO and not just the incorrect REISERFS_PROC_INFO.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sb_read may return NULL, let's explicitly check it. If so free new bitmap
blocks array, after this we may safely exit as it done above during bitmap
allocation.
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sb_read may return NULL, so let's explicitly check it.
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace (n & (n-1)) in the context of power of 2 checks with is_power_of_2
Signed-off-by: vignesh babu <vignesh.babu@wipro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace (n & (n-1)) in the context of power of 2 checks with is_power_of_2
Signed-off-by: vignesh babu <vignesh.babu@wipro.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replacing (n & (n-1)) in the context of power of 2 checks with
is_power_of_2
Signed-off-by: vignesh babu <vignesh.babu@wipro.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, devpts doesn't generate an fsnotify event upon pts creation
because the regular vfs paths aren't involved. Deallocation, on the other
hand, correctly generates a nameremove event thanks to the d_delete()
invocation in devpts_pty_kill().
This patch adds the missing fsnotify_create() trigger in devpts_pty_new().
Signed-off-by: Florin Malita <fmalita@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add SEEK_MAX and use it to validate lseek arguments from userspace.
Signed-off-by: Chris Snook <csnook@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert magic numbers to SEEK_* values from fs.h
Signed-off-by: Chris Snook <csnook@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Teach the dentry slab shrinker to aggressively shrink parent dentries when
shrinking the dentry cache.
This is done to attempt to improve the situation where the dentry slab cache
gets a lot of internal fragmentation due to pages containing directory
dentries. It is expected that this change will cause some of those dentries
to be reaped earlier, and with less scanning.
Needs careful testing.
Cc: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The time shrink_dcache_parent() takes, grows quadratically with the depth
of the tree under 'parent'. This starts to get noticable at about 10,000.
These kinds of depths don't occur normally, and filesystems which invoke
shrink_dcache_parent() via d_invalidate() seem to have other depth
dependent timings, so it's not even easy to expose this problem.
However with FUSE it's easy to create a deep tree and d_invalidate()
will also get called. This can make a syscall hang for a very long
time.
This is the original discovery of the problem by Russ Cox:
http://article.gmane.org/gmane.comp.file-systems.fuse.devel/3826
The following patch fixes the quadratic behavior, by optionally allowing
prune_dcache() to prune ancestors of a dentry in one go, instead of doing
it one at a time.
Common code in dput() and prune_one_dentry() is extracted into a new helper
function d_kill().
shrink_dcache_parent() as well as shrink_dcache_sb() are converted to use
the ancestry-pruner option. Only for shrink_dcache_memory() is this
behavior not desirable, so it keeps using the old algorithm.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This past week I was playing around with that pahole tool
(http://oops.ghostprotocols.net:81/acme/dwarves/) and looking at the size
of various struct in the kernel. I was surprised by the size of the
task_struct on x86_64, approaching 4K. I looked through the fields in
task_struct and found that a number of them were declared as "unsigned
long" rather than "unsigned int" despite them appearing okay as 32-bit
sized fields. On x86_64 "unsigned long" ends up being 8 bytes in size and
forces 8 byte alignment. Is there a reason there a reason they are
"unsigned long"?
The patch below drops the size of the struct from 3808 bytes (60 64-byte
cachelines) to 3760 bytes (59 64-byte cachelines). A couple other fields
in the task struct take a signficant amount of space:
struct thread_struct thread; 688
struct held_lock held_locks[30]; 1680
CONFIG_LOCKDEP is turned on in the .config
[akpm@linux-foundation.org: fix printk warnings]
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Taken from http://bugzilla.kernel.org/show_bug.cgi?id=5079
signed long ranges from -2.147.483.648 to 2.147.483.647 on x86 32bit
10000011110110100100111110111101 .. -2,082,844,739
10000011110110100100111110111101 .. 2,212,122,557 <- this currently gets
stored on the disk but when converting it to a 64bit signed long value it loses
its sign and becomes positive.
Cc: Andreas Dilger <adilger@dilger.ca>
Cc: <linux-ext4@vger.kernel.org>
Andreas says:
This patch is now treating timestamps with the high bit set as negative
times (before Jan 1, 1970). This means we lose 1/2 of the possible range
of timestamps (lopping off 68 years before unix timestamp overflow -
now only 30 years away :-) to handle the extremely rare case of setting
timestamps into the distant past.
If we are only interested in fixing the underflow case, we could just
limit the values to 0 instead of storing negative values. At worst this
will skew the timestamp by a few hours for timezones in the far east
(files would still show Jan 1, 1970 in "ls -l" output).
That said, it seems 32-bit systems (mine at least) allow files to be set
into the past (01/01/1907 works fine) so it seems this patch is bringing
the x86_64 behaviour into sync with other kernels.
On the plus side, we have a patch that is ready to add nanosecond timestamps
to ext3 and as an added bonus adds 2 high bits to the on-disk timestamp so
this extends the maximum date to 2242.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/proc/$PID/fd has r-x------ permissions, so if process does setuid(), it
will not be able to access /proc/*/fd/. This breaks fstatat() emulation
in glibc.
open("foo", O_RDONLY|O_DIRECTORY) = 4
setuid32(65534) = 0
stat64("/proc/self/fd/4/bar", 0xbfafb298) = -1 EACCES (Permission denied)
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Acked-By: Kirill Korotaev <dev@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
block_write_full_page() forgot to propagate ENPSOC into the address_space.
Cc: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup: setting an outstanding error on a mapping was open coded too many
times. Factor it out in mapping_set_error().
Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hostfs needed some style goodness.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch allows hostfs_setattr() to work on unlinked open files by calling
set_attr() (the userspace part) with the inode's fd.
Without this, applications that depend on doing attribute changes to unlinked
open files will fail.
It works by using the fd versions instead of the path ones (for example
fchmod() instead of chmod(), fchown() instead of chown()) when an fd is
available.
Signed-off-by: Alberto Bertogli <albertito@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Dumazet, thank you for disclosing this bug.
Readahead logic somehow fails to populate the page range with data.
It can be because
1) the readahead routine is not always called in the following lines of
fs/splice.c:
if (!loff || nr_pages > 1)
page_cache_readahead(mapping, &in->f_ra, in, index, nr_pages);
2) even called, page_cache_readahead() wont guarantee the pages are there.
It wont submit readahead I/O for pages already in the radix tree, or when
(ra_pages == 0), or after 256 cache hits.
In your case, it should be because of the retried reads, which lead to
excessive cache hits, and disables readahead at some time.
And that _one_ failure of readahead blocks the whole read process.
The application receives EAGAIN and retries the read, but
__generic_file_splice_read() refuse to make progress:
- in the previous invocation, it has allocated a blank page and inserted it
into the radix tree, but never has the chance to start I/O for it: the test
of SPLICE_F_NONBLOCK goes before that.
- in the retried invocation, the readahead code will neither get out of the
cache hit mode, nor will it submit I/O for an already existing page.
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
In xfs_write() the iolock is dropped and reacquired in XFS_SEND_DATA()
which means that the file could change from not-cached to cached and we
need to redo the direct I/O checks. We should also redo the direct I/O
checks when the file size changes regardless if O_APPEND is set or not.
SGI-PV: 963483
SGI-Modid: xfs-linux-melb:xfs-kern:28440a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.
There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.
The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.
SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
This change addresses a race in xfs_write() where, for direct I/O, the
flags need_i_mutex and need_flush are setup before the iolock is acquired.
The logic used to setup the flags may change between setting the flags and
acquiring the iolock resulting in these flags having incorrect values. For
example, if a file is not currently cached then need_i_mutex is set to
zero and then if the file is cached before the iolock is acquired we will
fail to do the flushinval before the direct write.
The flush (and also the call to xfs_zero_eof()) need to be done with the
iolock held exclusive so we need to acquire the iolock before checking for
cached data (or if the write begins after eof) to prevent this state from
changing. For direct I/O I've chosen to always acquire the iolock in
shared mode initially and if there is a need to promote it then drop it
and reacquire it.
There's also some other tidy-ups including removing the O_APPEND offset
adjustment since that work is done in generic_write_checks() (and we don't
use offset as an input parameter anywhere).
SGI-PV: 962170
SGI-Modid: xfs-linux-melb:xfs-kern:28319a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
When uquota and oquota (gquota/pquota) are enabled for accounting both are
enforced if ether has enforcement active.
Conditions:
- Both XFS_UQUOTA_ACCT and XFS_GQUOTA_ACCT are enabled.
- Either XFS_UQUOTA_ENFD or XFS_OQUOTA_ENFD is enabled.
- The usage without enforce is reached at the soft limit.
Problems:
1. "repquota" shows all grace time even if no enforcement.
2. we cannot make a file over a hard limits even if no enforcement.
SGI-PV: 962291
SGI-Modid: xfs-linux-melb:xfs-kern:28272a
Signed-off-by: Kouta Ooizumi <k-ooizumi@tnes.nec.co.jp>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
This patch handles error return values in fs_flush_pages and
fs_flushinval_pages. It changes the prototype of fs_flushinval_pages so we
can propogate the errors and handle them at higher layers. I also modified
xfs_itruncate_start so that it could propogate the error further.
SGI-PV: 961990
SGI-Modid: xfs-linux-melb:xfs-kern:28231a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Stewart Smith <stewart@flamingspork.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
xfs_qm_scall_quotaon was incorrectly failing requests to enable group
quota enforcement. Fixes logic error in OQUOTA handling.
SGI-PV: 961964
SGI-Modid: xfs-linux-melb:xfs-kern:28227a
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
When quotas are mounted or remounted without a particular quota type the
quota accounting for that type becomes invalid. Previously we were
ignoring this leading to accounting errors.
SGI-PV: 961964
SGI-Modid: xfs-linux-melb:xfs-kern:28225a
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Utako Kusaka <utako@tnes.nec.co.jp>
Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
* 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linux:
gfs2: nfs lock support for gfs2
lockd: add code to handle deferred lock requests
lockd: always preallocate block in nlmsvc_lock()
lockd: handle test_lock deferrals
lockd: pass cookie in nlmsvc_testlock
lockd: handle fl_grant callbacks
lockd: save lock state on deferral
locks: add fl_grant callback for asynchronous lock return
nfsd4: Convert NFSv4 to new lock interface
locks: add lock cancel command
locks: allow {vfs,posix}_lock_file to return conflicting lock
locks: factor out generic/filesystem switch from setlock code
locks: factor out generic/filesystem switch from test_lock
locks: give posix_test_lock same interface as ->lock
locks: make ->lock release private data before returning in GETLK case
locks: create posix-to-flock helper functions
locks: trivial removal of unnecessary parentheses
This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix! Tinyboards.
The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc. (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000. Since then ADI has put this core into its Blackfin
processor family of devices. The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set. It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.
The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdf
The Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibc
This patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/
We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel
[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If hugetlbfs module_init() fails, hugetlbfs_vfsmount is not initialized and
shmget() with SHM_HUGETLB flag will cause NULL pointer dereference.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by
SLAB.
I think its purpose was to have a callback after an object has been freed
to verify that the state is the constructor state again? The callback is
performed before each freeing of an object.
I would think that it is much easier to check the object state manually
before the free. That also places the check near the code object
manipulation of the object.
Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
compiled with SLAB debugging on. If there would be code in a constructor
handling SLAB_DEBUG_INITIAL then it would have to be conditional on
SLAB_DEBUG otherwise it would just be dead code. But there is no such code
in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real
use of, difficult to understand and there are easier ways to accomplish the
same effect (i.e. add debug code before kfree).
There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
clear in fs inode caches. Remove the pointless checks (they would even be
pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.
This is the last slab flag that SLUB did not support. Remove the check for
unimplemented flags from SLUB.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Generic hugetlb_get_unmapped_area() now handles MAP_FIXED by just calling
prepare_hugepage_range()
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: William Irwin <bill.irwin@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides a new macro
KMEM_CACHE(<struct>, <flags>)
to simplify slab creation. KMEM_CACHE creates a slab with the name of the
struct, with the size of the struct and with the alignment of the struct.
Additional slab flags may be specified if necessary.
Example
struct test_slab {
int a,b,c;
struct list_head;
} __cacheline_aligned_in_smp;
test_slab_cache = KMEM_CACHE(test_slab, SLAB_PANIC)
will create a new slab named "test_slab" of the size sizeof(struct
test_slab) and aligned to the alignment of test slab. If it fails then we
panic.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
invalidate_bdev() is superfluous when truncate_inode_pages() is also
called. do call invalidate_bh_lrus() though, to avoid stale pointers.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove duplicate work in kill_bdev().
It currently invalidates and then truncates the bdev's mapping.
invalidate_mapping_pages() will opportunistically remove pages from the
mapping. And truncate_inode_pages() will forcefully remove all pages.
The only thing truncate doesn't do is flush the bh lrus. So do that
explicitly. This avoids (very unlikely) but possible invalid lookup
results if the same bdev is quickly re-issued.
It also will prevent extreme kernel latencies which are observed when
blockdevs which have a large amount of pagecache are unmounted, by avoiding
invalidate_mapping_pages() on that path. invalidate_mapping_pages() has no
cond_resched (it can be called under spinlock), whereas truncate_inode_pages()
has one.
[akpm@linux-foundation.org: restore nrpages==0 optimisation]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the destroy_dirty_buffers argument from invalidate_bdev(), it hasn't
been used in 6 years (so akpm says).
find * -name \*.[ch] | xargs grep -l invalidate_bdev |
while read file; do
quilt add $file;
sed -ie 's/invalidate_bdev(\([^,]*\),[^)]*)/invalidate_bdev(\1)/g' $file;
done
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we add a new flag so that we can distinguish between the first page and the
tail pages then we can avoid to use page->private in the first page.
page->private == page for the first page, so there is no real information in
there.
Freeing up page->private makes the use of compound pages more transparent.
They become more usable like real pages. Right now we have to be careful f.e.
if we are going beyond PAGE_SIZE allocations in the slab on i386 because we
can then no longer use the private field. This is one of the issues that
cause us not to support debugging for page size slabs in SLAB.
Having page->private available for SLUB would allow more meta information in
the page struct. I can probably avoid the 16 bit ints that I have in there
right now.
Also if page->private is available then a compound page may be equipped with
buffer heads. This may free up the way for filesystems to support larger
blocks than page size.
We add PageTail as an alias of PageReclaim. Compound pages cannot currently
be reclaimed. Because of the alias one needs to check PageCompound first.
The RFC for the this approach was discussed at
http://marc.info/?t=117574302800001&r=1&w=2
[nacc@us.ibm.com: fix hugetlbfs]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adds /proc/pid/clear_refs. When any non-zero number is written to this file,
pte_mkold() and ClearPageReferenced() is called for each pte and its
corresponding page, respectively, in that task's VMAs. This file is only
writable by the user who owns the task.
It is now possible to measure _approximately_ how much memory a task is using
by clearing the reference bits with
echo 1 > /proc/pid/clear_refs
and checking the reference count for each VMA from the /proc/pid/smaps output
at a measured time interval. For example, to observe the approximate change
in memory footprint for a task, write a script that clears the references
(echo 1 > /proc/pid/clear_refs), sleeps, and then greps for Pgs_Referenced and
extracts the size in kB. Add the sizes for each VMA together for the total
referenced footprint. Moments later, repeat the process and observe the
difference.
For example, using an efficient Mozilla:
accumulated time referenced memory
---------------- -----------------
0 s 408 kB
1 s 408 kB
2 s 556 kB
3 s 1028 kB
4 s 872 kB
5 s 1956 kB
6 s 416 kB
7 s 1560 kB
8 s 2336 kB
9 s 1044 kB
10 s 416 kB
This is a valuable tool to get an approximate measurement of the memory
footprint for a task.
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
[akpm@linux-foundation.org: build fixes]
[mpm@selenic.com: rename for_each_pmd]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
