1. 28 Jul, 2010 4 commits
  2. 21 May, 2010 2 commits
    • Al Viro's avatar
      Saner locking around deactivate_super() · 1712ac8f
      Al Viro authored
      
      
      Make sure that s_umount is acquired *before* we drop the final
      active reference; we still have the fast path (atomic_dec_unless)
      and we have gotten rid of the window between the moment when
      s_active hits zero and s_umount is acquired.  Which simplifies
      the living hell out of grab_super() and inotify pin_to_kill()
      stuff.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      1712ac8f
    • Al Viro's avatar
      get rid of S_BIAS · b20bd1a5
      Al Viro authored
      
      
      use atomic_inc_not_zero(&sb->s_active) instead of playing games with
      checking ->s_count > S_BIAS
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      b20bd1a5
  3. 14 May, 2010 3 commits
  4. 12 May, 2010 1 commit
  5. 30 Apr, 2010 1 commit
    • Ralf Baechle's avatar
      Inotify: Fix build failure in inotify user support · 12b1b321
      Ralf Baechle authored
      
      
      CONFIG_INOTIFY_USER defined but CONFIG_ANON_INODES undefined will result
      in the following build failure:
      
          LD      vmlinux
        fs/built-in.o: In function 'sys_inotify_init1':
        (.text.sys_inotify_init1+0x22c): undefined reference to 'anon_inode_getfd'
        fs/built-in.o: In function `sys_inotify_init1':
        (.text.sys_inotify_init1+0x22c): relocation truncated to fit: R_MIPS_26 against 'anon_inode_getfd'
        make[2]: *** [vmlinux] Error 1
        make[1]: *** [sub-make] Error 2
        make: *** [all] Error 2
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      12b1b321
  6. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2
      
       to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  7. 19 Feb, 2010 1 commit
  8. 15 Jan, 2010 2 commits
    • Eric Paris's avatar
      inotify: only warn once for inotify problems · 976ae32b
      Eric Paris authored
      
      
      inotify will WARN() if it finds that the idr and the fsnotify internals
      somehow got out of sync.  It was only supposed to do this once but due
      to this stupid bug it would warn every single time a problem was
      detected.
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      Cc: stable@kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      976ae32b
    • Eric Paris's avatar
      inotify: do not reuse watch descriptors · 9e572cc9
      Eric Paris authored
      Since commit 7e790dd5
      
       ("inotify: fix
      error paths in inotify_update_watch") inotify changed the manor in which
      it gave watch descriptors back to userspace.  Previous to this commit
      inotify acted like the following:
      
        inotify_add_watch(X, Y, Z) = 1
        inotify_rm_watch(X, 1);
        inotify_add_watch(X, Y, Z) = 2
      
      but after this patch inotify would return watch descriptors like so:
      
        inotify_add_watch(X, Y, Z) = 1
        inotify_rm_watch(X, 1);
        inotify_add_watch(X, Y, Z) = 1
      
      which I saw as equivalent to opening an fd where
      
        open(file) = 1;
        close(1);
        open(file) = 1;
      
      seemed perfectly reasonable.  The issue is that quite a bit of userspace
      apparently relies on the behavior in which watch descriptors will not be
      quickly reused.  KDE relies on it, I know some selinux packages rely on
      it, and I have heard complaints from other random sources such as debian
      bug 558981.
      
      Although the man page implies what we do is ok, we broke userspace so
      this patch almost reverts us to the old behavior.  It is still slightly
      racey and I have patches that would fix that, but they are rather large
      and this will fix it for all real world cases.  The race is as follows:
      
       - task1 creates a watch and blocks in idr_new_watch() before it updates
         the hint.
       - task2 creates a watch and updates the hint.
       - task1 updates the hint with it's older wd
       - task removes the watch created by task2
       - task adds a new watch and will reuse the wd originally given to task2
      
      it requires moving some locking around the hint (last_wd) but this should
      solve it for the real world and be -stable safe.
      
      As a side effect this patch papers over a bug in the lib/idr code which
      is causing a large number WARN's to pop on people's system and many
      reports in kerneloops.org.  I'm working on the root cause of that idr
      bug seperately but this should make inotify immune to that issue.
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      Cc: stable@kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9e572cc9
  9. 16 Dec, 2009 2 commits
  10. 04 Dec, 2009 1 commit
  11. 18 Nov, 2009 1 commit
  12. 12 Nov, 2009 1 commit
  13. 20 Oct, 2009 1 commit
    • Andreas Gruenbacher's avatar
      dnotify: ignore FS_EVENT_ON_CHILD · 94552684
      Andreas Gruenbacher authored
      Mask off FS_EVENT_ON_CHILD in dnotify_handle_event().  Otherwise, when there
      is more than one watch on a directory and dnotify_should_send_event()
      succeeds, events with FS_EVENT_ON_CHILD set will trigger all watches and cause
      spurious events.
      
      This case was overlooked in commit e42e2773
      
      .
      
      	#define _GNU_SOURCE
      
      	#include <stdio.h>
      	#include <stdlib.h>
      	#include <unistd.h>
      	#include <signal.h>
      	#include <sys/types.h>
      	#include <sys/stat.h>
      	#include <fcntl.h>
      	#include <string.h>
      
      	static void create_event(int s, siginfo_t* si, void* p)
      	{
      		printf("create\n");
      	}
      
      	static void delete_event(int s, siginfo_t* si, void* p)
      	{
      		printf("delete\n");
      	}
      
      	int main (void) {
      		struct sigaction action;
      		char *tmpdir, *file;
      		int fd1, fd2;
      
      		sigemptyset (&action.sa_mask);
      		action.sa_flags = SA_SIGINFO;
      
      		action.sa_sigaction = create_event;
      		sigaction (SIGRTMIN + 0, &action, NULL);
      
      		action.sa_sigaction = delete_event;
      		sigaction (SIGRTMIN + 1, &action, NULL);
      
      	#	define TMPDIR "/tmp/test.XXXXXX"
      		tmpdir = malloc(strlen(TMPDIR) + 1);
      		strcpy(tmpdir, TMPDIR);
      		mkdtemp(tmpdir);
      
      	#	define TMPFILE "/file"
      		file = malloc(strlen(tmpdir) + strlen(TMPFILE) + 1);
      		sprintf(file, "%s/%s", tmpdir, TMPFILE);
      
      		fd1 = open (tmpdir, O_RDONLY);
      		fcntl(fd1, F_SETSIG, SIGRTMIN);
      		fcntl(fd1, F_NOTIFY, DN_MULTISHOT | DN_CREATE);
      
      		fd2 = open (tmpdir, O_RDONLY);
      		fcntl(fd2, F_SETSIG, SIGRTMIN + 1);
      		fcntl(fd2, F_NOTIFY, DN_MULTISHOT | DN_DELETE);
      
      		if (fork()) {
      			/* This triggers a create event */
      			creat(file, 0600);
      			/* This triggers a create and delete event (!) */
      			unlink(file);
      		} else {
      			sleep(1);
      			rmdir(tmpdir);
      		}
      
      		return 0;
      	}
      Signed-off-by: default avatarAndreas Gruenbacher <agruen@suse.de>
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      94552684
  14. 18 Oct, 2009 2 commits
    • Wei Yongjun's avatar
      inotify: fix coalesce duplicate events into a single event in special case · 3de0ef4f
      Wei Yongjun authored
      
      
      If we do rename a dir entry, like this:
      
        rename("/tmp/ino7UrgoJ.rename1", "/tmp/ino7UrgoJ.rename2")
        rename("/tmp/ino7UrgoJ.rename2", "/tmp/ino7UrgoJ")
      
      The duplicate events should be coalesced into a single event. But those two
      events do not be coalesced into a single event, due to some bad check in
      event_compare(). It can not match the two NULL inodes as the same event.
      Signed-off-by: default avatarWei Yongjun <yjwei@cn.fujitsu.com>
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      3de0ef4f
    • Eric Paris's avatar
      fsnotify: do not set group for a mark before it is on the i_list · 9f0d793b
      Eric Paris authored
      
      
      fsnotify_add_mark is supposed to add a mark to the g_list and i_list and to
      set the group and inode for the mark.  fsnotify_destroy_mark_by_entry uses
      the fact that ->group != NULL to know if this group should be destroyed or
      if it's already been done.
      
      But fsnotify_add_mark sets the group and inode before it actually adds the
      mark to the i_list and g_list.  This can result in a race in inotify, it
      requires 3 threads.
      
      sys_inotify_add_watch("file")	sys_inotify_add_watch("file")	sys_inotify_rm_watch([a])
      inotify_update_watch()
      inotify_new_watch()
      inotify_add_to_idr()
         ^--- returns wd = [a]
      				inotfiy_update_watch()
      				inotify_new_watch()
      				inotify_add_to_idr()
      				fsnotify_add_mark()
      				   ^--- returns wd = [b]
      				returns to userspace;
      								inotify_idr_find([a])
      								   ^--- gives us the pointer from task 1
      fsnotify_add_mark()
         ^--- this is going to set the mark->group and mark->inode fields, but will
      return -EEXIST because of the race with [b].
      								fsnotify_destroy_mark()
      								   ^--- since ->group != NULL we call back
      									into inotify_freeing_mark() which calls
      								inotify_remove_from_idr([a])
      
      since fsnotify_add_mark() failed we call:
      inotify_remove_from_idr([a])     <------WHOOPS it's not in the idr, this could
      					have been any entry added later!
      
      The fix is to make sure we don't set mark->group until we are sure the mark is
      on the inode and fsnotify_add_mark will return success.
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      9f0d793b
  15. 28 Aug, 2009 3 commits
  16. 27 Aug, 2009 4 commits
  17. 17 Aug, 2009 3 commits
  18. 21 Jul, 2009 7 commits
    • Eric Paris's avatar
      inotify: use GFP_NOFS under potential memory pressure · f44aebcc
      Eric Paris authored
      
      
      inotify can have a watchs removed under filesystem reclaim.
      
      =================================
      [ INFO: inconsistent lock state ]
      2.6.31-rc2 #16
      ---------------------------------
      inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
      khubd/217 [HC0[0]:SC0[0]:HE1:SE1] takes:
       (iprune_mutex){+.+.?.}, at: [<c10ba899>] invalidate_inodes+0x20/0xe3
      {IN-RECLAIM_FS-W} state was registered at:
        [<c10536ab>] __lock_acquire+0x2c9/0xac4
        [<c1053f45>] lock_acquire+0x9f/0xc2
        [<c1308872>] __mutex_lock_common+0x2d/0x323
        [<c1308c00>] mutex_lock_nested+0x2e/0x36
        [<c10ba6ff>] shrink_icache_memory+0x38/0x1b2
        [<c108bfb6>] shrink_slab+0xe2/0x13c
        [<c108c3e1>] kswapd+0x3d1/0x55d
        [<c10449b5>] kthread+0x66/0x6b
        [<c1003fdf>] kernel_thread_helper+0x7/0x10
        [<ffffffff>] 0xffffffff
      
      Two things are needed to fix this.  First we need a method to tell
      fsnotify_create_event() to use GFP_NOFS and second we need to stop using
      one global IN_IGNORED event and allocate them one at a time.  This solves
      current issues with multiple IN_IGNORED on a queue having tail drop
      problems and simplifies the allocations since we don't have to worry about
      two tasks opperating on the IGNORED event concurrently.
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      f44aebcc
    • Eric Paris's avatar
      fsnotify: fix inotify tail drop check with path entries · c05594b6
      Eric Paris authored
      
      
      fsnotify drops new events when they are the same as the tail event on the
      queue to be sent to userspace.  The problem is that if the event comes with
      a path we forget to break out of the switch statement and fall into the
      code path which matches on events that do not have any type of file backed
      information (things like IN_UNMOUNT and IN_Q_OVERFLOW).  The problem is
      that this code thinks all such events should be dropped.  Fix is to add a
      break.
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      c05594b6
    • Eric Paris's avatar
      inotify: check filename before dropping repeat events · 4a148ba9
      Eric Paris authored
      
      
      inotify drops events if the last event on the queue is the same as the
      current event.  But it does 2 things wrong.  First it is comparing old->inode
      with new->inode.  But after an event if put on the queue the ->inode is no
      longer allowed to be used.  It's possible between the last event and this new
      event the inode could be reused and we would falsely match the inode's memory
      address between two differing events.
      
      The second problem is that when a file is removed fsnotify is passed the
      negative dentry for the removed object rather than the postive dentry from
      immediately before the removal.  This mean the (broken) inotify tail drop code
      was matching the NULL ->inode of differing events.
      
      The fix is to check the file name which is stored with events when doing the
      tail drop instead of wrongly checking the address of the stored ->inode.
      Reported-by: default avatarScott James Remnant <scott@ubuntu.com>
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      4a148ba9
    • Eric Paris's avatar
      fsnotify: use def_bool in kconfig instead of letting the user choose · 520dc2a5
      Eric Paris authored
      
      
      fsnotify doens't give the user anything.  If someone chooses inotify or
      dnotify it should build fsnotify, if they don't select one it shouldn't be
      built.  This patch changes fsnotify to be a def_bool=n and makes everything
      else select it.  Also fixes the issue people complained about on lwn where
      gdm hung because they didn't have inotify and they didn't get the inotify
      build option.....
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      520dc2a5
    • Eric Paris's avatar
      inotify: fix error paths in inotify_update_watch · 7e790dd5
      Eric Paris authored
      
      
      inotify_update_watch could leave things in a horrid state on a number of
      error paths.  We could try to remove idr entries that didn't exist, we
      could send an IN_IGNORED to userspace for watches that don't exist, and a
      bit of other stupidity.  Clean these up by doing the idr addition before we
      put the mark on the inode since we can clean that up on error and getting
      off the inode's mark list is hard.
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      7e790dd5
    • Eric Paris's avatar
      inotify: do not leak inode marks in inotify_add_watch · 75fe2b26
      Eric Paris authored
      
      
      inotify_add_watch had a couple of problems.  The biggest being that if
      inotify_add_watch was called on the same inode twice (to update or change the
      event mask) a refence was taken on the original inode mark by
      fsnotify_find_mark_entry but was not being dropped at the end of the
      inotify_add_watch call.  Thus if inotify_rm_watch was called although the mark
      was removed from the inode, the refcnt wouldn't hit zero and we would leak
      memory.
      Reported-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      75fe2b26
    • Eric Paris's avatar
      inotify: drop user watch count when a watch is removed · 5549f7cd
      Eric Paris authored
      
      
      The inotify rewrite forgot to drop the inotify watch use cound when a watch
      was removed.  This means that a single inotify fd can only ever register a
      maximum of /proc/sys/fs/max_user_watches even if some of those had been
      freed.
      Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      5549f7cd