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2007-05-08nfs: fix congestion control: use atomic_longsPeter Zijlstra
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>
2007-05-08utimensat implementationUlrich Drepper
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>
2007-05-08inode numbering: change libfs sb creation routines to avoid collisions with ↵Jeff Layton
their root inodes 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>
2007-05-08inode numbering: make static counters in new_inode and iunique be 32 bitsJeff Layton
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>
2007-05-08Invalid return value of execve() resulting in oopsesAlexey Kuznetsov
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>
2007-05-08procfs: use simple_read_from_buffer()Akinobu Mita
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>
2007-05-08Fix error handling in HDIO_GETGEO compat wrapperAndreas Schwab
Don't clobber error from sys_ioctl in HDIO_GETGEO compat wrapper. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08udf: decrement correct link count in udf_rmdirStephen Mollett
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>
2007-05-08fat: fix VFAT compat ioctls on 64-bit systemsOGAWA Hirofumi
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>
2007-05-08ext3: copy i_flags to inode flags on writeJan Kara
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>
2007-05-08fat: don't use free_clusters for fat32OGAWA Hirofumi
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>
2007-05-08reiserfs: use __set_current_state()Milind Arun Choudhary
use __set_current_state(TASK_*) instead of current->state = TASK_*, in fs/reiserfs Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com> Cc: <reiserfs-dev@namesys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08jbd: check for error returned by kthread_create on creating journal threadPavel Emelianov
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>
2007-05-08check privileges before setting mount propagationMiklos Szeredi
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>
2007-05-08ext3: copy i_flags to inode flags on writeJan Kara
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>
2007-05-08Introduce a handy list_first_entry macroPavel Emelianov
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>
2007-05-08smbfs: remove unnecessary allow_signalEric W. Biederman
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>
2007-05-08make iunique use a do/while loop rather than its obscure goto loopJeffrey Layton
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>
2007-05-08Remove redundant check from proc_sys_setattr()John Johansen
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>
2007-05-08Remove redundant check from proc_setattr()John Johansen
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>
2007-05-08proc: cleanup: use seq_release_private() where appropriateMartin Peschke
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>
2007-05-08cleanup compat ioctl handlingChristoph Hellwig
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>
2007-05-08partition: add support for sysv68 partitionsPhilippe De Muyter
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>
2007-05-08merge compat_ioctl.h into compat_ioctl.cChristoph Hellwig
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>
2007-05-08ROUND_UP macro cleanup in fs/smbfs/request.cMilind Arun Choudhary
ROUND_UP macro cleanup use ALIGN Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08ROUND_UP macro cleanup in fs/(select|compat|readdir).cMilind Arun Choudhary
ROUND_UP macro cleanup use,ALIGN or DIV_ROUND_UP where ever appropriate. Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08i386: sched.h inclusion from module.h is baackAlexey Dobriyan
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>
2007-05-08Fix race between cat /proc/*/wchan and rmmod et alAlexey Dobriyan
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>
2007-05-08Simplify kallsyms_lookup()Alexey Dobriyan
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>
2007-05-08(re)register_binfmt returns with -EBUSYkalash nainwal
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>
2007-05-08header cleaning: don't include smp_lock.h when not usedRandy Dunlap
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>
2007-05-08make remove_inode_dquot_ref() staticAdrian Bunk
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>
2007-05-08Protect tty drivers list with tty_mutexAlexey Dobriyan
Additions and removal from tty_drivers list were just done as well as iterating on it for /proc/tty/drivers generation. testing: modprobe/rmmod loop of simple module which does nothing but tty_register_driver() vs cat /proc/tty/drivers loop BUG: unable to handle kernel paging request at virtual address 6b6b6b6b printing eip: c01cefa7 *pde = 00000000 Oops: 0000 [#1] PREEMPT last sysfs file: devices/pci0000:00/0000:00:1d.7/usb5/5-0:1.0/bInterfaceProtocol Modules linked in: ohci_hcd af_packet e1000 ehci_hcd uhci_hcd usbcore xfs CPU: 0 EIP: 0060:[<c01cefa7>] Not tainted VLI EFLAGS: 00010297 (2.6.21-rc4-mm1 #4) EIP is at vsnprintf+0x3a4/0x5fc eax: 6b6b6b6b ebx: f6cb50f2 ecx: 6b6b6b6b edx: fffffffe esi: c0354700 edi: f6cb6000 ebp: 6b6b6b6b esp: f31f5e68 ds: 007b es: 007b fs: 00d8 gs: 0033 ss: 0068 Process cat (pid: 31864, ti=f31f4000 task=c1998030 task.ti=f31f4000) Stack: 00000000 c0103f20 c013003a c0103f20 00000000 f6cb50da 0000000a 00000f0e f6cb50f2 00000010 00000014 ffffffff ffffffff 00000007 c0354753 f6cb50f2 f73e39dc f73e39dc 00000001 c0175416 f31f5ed8 f31f5ed4 0ee00000 f32090bc Call Trace: [<c0103f20>] restore_nocheck+0x12/0x15 [<c013003a>] mark_held_locks+0x6d/0x86 [<c0103f20>] restore_nocheck+0x12/0x15 [<c0175416>] seq_printf+0x2e/0x52 [<c0192895>] show_tty_range+0x35/0x1f3 [<c0175416>] seq_printf+0x2e/0x52 [<c0192add>] show_tty_driver+0x8a/0x1d9 [<c01758f6>] seq_read+0x70/0x2ba [<c0175886>] seq_read+0x0/0x2ba [<c018d8e6>] proc_reg_read+0x63/0x9f [<c015e764>] vfs_read+0x7d/0xb5 [<c018d883>] proc_reg_read+0x0/0x9f [<c015eab1>] sys_read+0x41/0x6a [<c0103e4e>] sysenter_past_esp+0x5f/0x99 ======================= Code: 00 8b 4d 04 e9 44 ff ff ff 8d 4d 04 89 4c 24 50 8b 6d 00 81 fd ff 0f 00 00 b8 a4 c1 35 c0 0f 46 e8 8b 54 24 2c 89 e9 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 89 c6 8b 44 24 28 89 EIP: [<c01cefa7>] vsnprintf+0x3a4/0x5fc SS:ESP 0068:f31f5e68 Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Remove do_sync_file_range()Mark Fasheh
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>
2007-05-08reiserfs: proc support requires PROC_FSRandy Dunlap
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>
2007-05-08/proc/*/oom_score oops re badnessAlexey Dobriyan
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>
2007-05-08VFS: delay the dentry name generation on sockets and pipesEric Dumazet
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>
2007-05-08add file position info to procMiklos Szeredi
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>
2007-05-08procfs: reorder struct pid_dentry to save space on 64bit archs, and constify ↵Eric Dumazet
them 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>
2007-05-08proc: maps protectionKees Cook
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>
2007-05-08namei.c: remove utterly outdated commentChristoph Hellwig
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>
2007-05-08vfs: remove superflous sb == NULL checksChristoph Hellwig
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>
2007-05-08proc: remove pathetic ->deleted WARN_ONAlexey Dobriyan
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>
2007-05-08Fix race between proc_readdir and remove_proc_entryDarrick J. Wong
Fix the following race: proc_readdir remove_proc_entry ============ ================= spin_lock(&proc_subdir_lock); [choose PDE to start filldir from] spin_unlock(&proc_subdir_lock); spin_lock(&proc_subdir_lock); [find PDE] [free PDE, refcount is 0] spin_unlock(&proc_subdir_lock); /* boom */ if (filldir(dirent, de->name, ... [de_put on error path --adobriyan] Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> 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>
2007-05-08Fix race between proc_get_inode() and remove_proc_entry()Alexey Dobriyan
proc_lookup remove_proc_entry =========== ================= lock_kernel(); spin_lock(&proc_subdir_lock); [find PDE with refcount 0] spin_unlock(&proc_subdir_lock); spin_lock(&proc_subdir_lock); [find PDE with refcount 0] [check refcount and free PDE] spin_unlock(&proc_subdir_lock); proc_get_inode: de_get(de); /* boom */ Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.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>
2007-05-08add filesystem subtype supportMiklos Szeredi
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>
2007-05-08epoll: optimizations and cleanupsDavide Libenzi
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>
2007-05-08ext3: dirindex error pointer issuesDmitriy Monakhov
- 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>
2007-05-08Merge sys_clone()/sys_unshare() nsproxy and namespace handlingBadari Pulavarty
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>
2007-05-08exec: fix remove_arg_zeroNick Piggin
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>