linux.git/fs/notify, branch v4.0

fanotify: fix event filtering with FAN_ONDIR set

2015-03-13T01:46:08+00:00

With FAN_ONDIR set, the user can end up getting events, which it hasn't
marked.  This was revealed with fanotify04 testcase failure on
Linux-4.0-rc1, and is a regression from 3.19, revealed with 66ba93c0d7fe6
("fanotify: don't set FAN_ONDIR implicitly on a marks ignored mask").

   # /opt/ltp/testcases/bin/fanotify04
   [ ... ]
  fanotify04    7  TPASS  :  event generated properly for type 100000
  fanotify04    8  TFAIL  :  fanotify04.c:147: got unexpected event 30
  fanotify04    9  TPASS  :  No event as expected

The testcase sets the adds the following marks : FAN_OPEN | FAN_ONDIR for
a fanotify on a dir.  Then does an open(), followed by close() of the
directory and expects to see an event FAN_OPEN(0x20).  However, the
fanotify returns (FAN_OPEN|FAN_CLOSE_NOWRITE(0x10)).  This happens due to
the flaw in the check for event_mask in fanotify_should_send_event() which
does:

	if (event_mask & marks_mask & ~marks_ignored_mask)
		return true;

where, event_mask == (FAN_ONDIR | FAN_CLOSE_NOWRITE),
       marks_mask == (FAN_ONDIR | FAN_OPEN),
       marks_ignored_mask == 0

Fix this by masking the outgoing events to the user, as we already take
care of FAN_ONDIR and FAN_EVENT_ON_CHILD.

Signed-off-by: Suzuki K. Poulose 
Tested-by: Lino Sanfilippo 
Reviewed-by: Jan Kara 
Cc: Eric Paris 
Cc: Will Deacon 

Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversions

2015-02-22T16:38:42+00:00

Fanotify probably doesn't want to watch autodirs so make it use d_can_lookup()
rather than d_is_dir() when checking a dir watch and give an error on fake
directories.

Signed-off-by: David Howells 
Signed-off-by: Al Viro

VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)

2015-02-22T16:38:41+00:00

Convert the following where appropriate:

 (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).

 (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).

 (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry).  This is actually more
     complicated than it appears as some calls should be converted to
     d_can_lookup() instead.  The difference is whether the directory in
     question is a real dir with a ->lookup op or whether it's a fake dir with
     a ->d_automount op.

In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).

Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer.  In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.

However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.

There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE.  Strictly, this was
intended for special directory entry types that don't have attached inodes.

The following perl+coccinelle script was used:

use strict;

my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
    die "Can't grep for S_ISDIR and co. callers";
@callers = <$fd>;
close($fd);
unless (@callers) {
    print "No matches\n";
    exit(0);
}

my @cocci = (
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISLNK(E->d_inode->i_mode)',
    '+ d_is_symlink(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISDIR(E->d_inode->i_mode)',
    '+ d_is_dir(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISREG(E->d_inode->i_mode)',
    '+ d_is_reg(E)' );

my $coccifile = "tmp.sp.cocci";
open($fd, ">$coccifile") || die $coccifile;
print($fd "$_\n") || die $coccifile foreach (@cocci);
close($fd);

foreach my $file (@callers) {
    chomp $file;
    print "Processing ", $file, "\n";
    system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 ||
	die "spatch failed";
}

[AV: overlayfs parts skipped]

Signed-off-by: David Howells 
Signed-off-by: Al Viro

fanotify: don't set FAN_ONDIR implicitly on a marks ignored mask

2015-02-10T22:30:28+00:00

Currently FAN_ONDIR is always set on a mark's ignored mask when the
event mask is extended without FAN_MARK_ONDIR being set.  This may
result in events for directories being ignored unexpectedly for call
sequences like

  fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN | FAN_ONDIR , AT_FDCWD, "dir");
  fanotify_mark(fd, FAN_MARK_ADD, FAN_CLOSE, AT_FDCWD, "dir");

Also FAN_MARK_ONDIR is only honored when adding events to a mark's mask,
but not for event removal.  Fix both issues by not setting FAN_ONDIR
implicitly on the ignore mask any more.  Instead treat FAN_ONDIR as any
other event flag and require FAN_MARK_ONDIR to be set by the user for
both event mask and ignore mask.  Furthermore take FAN_MARK_ONDIR into
account when set for event removal.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Lino Sanfilippo 
Reviewed-by: Jan Kara 
Cc: Eric Paris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: don't recalculate a marks mask if only the ignored mask changed

2015-02-10T22:30:28+00:00

If removing bits from a mark's ignored mask, the concerning
inodes/vfsmounts mask is not affected.  So don't recalculate it.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Lino Sanfilippo 
Reviewed-by: Jan Kara 
Cc: Eric Paris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: only destroy mark when both mask and ignored_mask are cleared

2015-02-10T22:30:28+00:00

In fanotify_mark_remove_from_mask() a mark is destroyed if only one of
both bitmasks (mask or ignored_mask) of a mark is cleared.  However the
other mask may still be set and contain information that should not be
lost.  So only destroy a mark if both masks are cleared.

Signed-off-by: Lino Sanfilippo 
Reviewed-by: Jan Kara 
Cc: Eric Paris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2015-01-21T05:12:21+00:00

Pull RCU updates from Paul E. McKenney:

  - Documentation updates.

  - Miscellaneous fixes.

  - Preemptible-RCU fixes, including fixing an old bug in the
    interaction of RCU priority boosting and CPU hotplug.

  - SRCU updates.

  - RCU CPU stall-warning updates.

  - RCU torture-test updates.

Signed-off-by: Ingo Molnar

sched, fanotify: Deal with nested sleeps

2015-01-09T10:18:12+00:00

As per e23738a7300a ("sched, inotify: Deal with nested sleeps").

fanotify_read is a wait loop with sleeps in. Wait loops rely on
task_struct::state and sleeps do too, since that's the only means of
actually sleeping. Therefore the nested sleeps destroy the wait loop
state and the wait loop breaks the sleep functions that assume
TASK_RUNNING (mutex_lock).

Fix this by using the new woken_wake_function and wait_woken() stuff,
which registers wakeups in wait and thereby allows shrinking the
task_state::state changes to the actual sleep part.

Reported-by: Yuanhan Liu 
Reported-by: Sedat Dilek 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Takashi Iwai 
Cc: Al Viro 
Cc: Eric Paris 
Cc: Linus Torvalds 
Cc: Eric Paris 
Link: http://lkml.kernel.org/r/20141216152838.GZ3337@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar

rcu: Make SRCU optional by using CONFIG_SRCU

2015-01-06T19:04:29+00:00

SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.

If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.

   text    data     bss     dec     hex filename
   2007       0       0    2007     7d7 kernel/rcu/srcu.o

Size of arch/powerpc/boot/zImage changes from

   text    data     bss     dec     hex filename
 831552   64180   23944  919676   e087c arch/powerpc/boot/zImage : before
 829504   64180   23952  917636   e0084 arch/powerpc/boot/zImage : after

so the savings are about ~2000 bytes.

Signed-off-by: Pranith Kumar 
CC: Paul E. McKenney 
CC: Josh Triplett 
CC: Lai Jiangshan 
Signed-off-by: Paul E. McKenney 
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]

fsnotify: remove destroy_list from fsnotify_mark

2014-12-13T20:42:53+00:00

destroy_list is used to track marks which still need waiting for srcu
period end before they can be freed.  However by the time mark is added to
destroy_list it isn't in group's list of marks anymore and thus we can
reuse fsnotify_mark->g_list for queueing into destroy_list.  This saves
two pointers for each fsnotify_mark.

Signed-off-by: Jan Kara 
Cc: Eric Paris 
Cc: Heinrich Schuchardt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds