Commit Graph

474 Commits

Author SHA1 Message Date
Amir Goldstein b469e7e47c fanotify: fix handling of events on child sub-directory
When an event is reported on a sub-directory and the parent inode has
a mark mask with FS_EVENT_ON_CHILD|FS_ISDIR, the event will be sent to
fsnotify() even if the event type is not in the parent mark mask
(e.g. FS_OPEN).

Further more, if that event happened on a mount or a filesystem with
a mount/sb mark that does have that event type in their mask, the "on
child" event will be reported on the mount/sb mark.  That is not
desired, because user will get a duplicate event for the same action.

Note that the event reported on the victim inode is never merged with
the event reported on the parent inode, because of the check in
should_merge(): old_fsn->inode == new_fsn->inode.

Fix this by looking for a match of an actual event type (i.e. not just
FS_ISDIR) in parent's inode mark mask and by not reporting an "on child"
event to group if event type is only found on mount/sb marks.

[backport hint: The bug seems to have always been in fanotify, but this
                patch will only apply cleanly to v4.19.y]

Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-08 15:43:48 +01:00
Jan Kara 721fb6fbfd fsnotify: Fix busy inodes during unmount
Detaching of mark connector from fsnotify_put_mark() can race with
unmounting of the filesystem like:

  CPU1				CPU2
fsnotify_put_mark()
  spin_lock(&conn->lock);
  ...
  inode = fsnotify_detach_connector_from_object(conn)
  spin_unlock(&conn->lock);
				generic_shutdown_super()
				  fsnotify_unmount_inodes()
				    sees connector detached for inode
				      -> nothing to do
				  evict_inode()
				    barfs on pending inode reference
  iput(inode);

Resulting in "Busy inodes after unmount" message and possible kernel
oops. Make fsnotify_unmount_inodes() properly wait for outstanding inode
references from detached connectors.

Note that the accounting of outstanding inode references in the
superblock can cause some cacheline contention on the counter. OTOH it
happens only during deletion of the last notification mark from an inode
(or during unlinking of watched inode) and that is not too bad. I have
measured time to create & delete inotify watch 100000 times from 64
processes in parallel (each process having its own inotify group and its
own file on a shared superblock) on a 64 CPU machine. Average and
standard deviation of 15 runs look like:

	Avg		Stddev
Vanilla	9.817400	0.276165
Fixed	9.710467	0.228294

So there's no statistically significant difference.

Fixes: 6b3f05d24d ("fsnotify: Detach mark from object list when last reference is dropped")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-25 15:49:19 +02:00
Amir Goldstein d0a6a87e40 fanotify: support reporting thread id instead of process id
In order to identify which thread triggered the event in a
multi-threaded program, add the FAN_REPORT_TID flag in fanotify_init to
opt-in for reporting the event creator's thread id information.

Signed-off-by: nixiaoming <nixiaoming@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-08 13:48:45 +02:00
Amir Goldstein bdd5a46fe3 fanotify: add BUILD_BUG_ON() to count the bits of fanotify constants
Also define the FANOTIFY_EVENT_FLAGS consisting of the extra flags
FAN_ONDIR and FAN_ON_CHILD.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-04 13:30:03 +02:00
Amir Goldstein a39f7ec417 fsnotify: convert runtime BUG_ON() to BUILD_BUG_ON()
The BUG_ON() statements to verify number of bits in ALL_FSNOTIFY_BITS
and ALL_INOTIFY_BITS are converted to build time check of the constant.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-04 13:28:50 +02:00
Amir Goldstein 23c9deeb32 fanotify: deprecate uapi FAN_ALL_* constants
We do not want to add new bits to the FAN_ALL_* uapi constants
because they have been exposed to userspace.  If there are programs
out there using these constants, those programs could break if
re-compiled with modified FAN_ALL_* constants and run on an old kernel.

We deprecate the uapi constants FAN_ALL_* and define new FANOTIFY_*
constants for internal use to replace them. New feature bits will be
added only to the new constants.

Cc: <linux-api@vger.kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-04 13:28:38 +02:00
Amir Goldstein a72fd224e3 fanotify: simplify handling of FAN_ONDIR
fanotify mark add/remove code jumps through hoops to avoid setting the
FS_ISDIR in the commulative object mask.

That was just papering over a bug in fsnotify() handling of the FS_ISDIR
extra flag. This bug is now fixed, so all the hoops can be removed along
with the unneeded internal flag FAN_MARK_ONDIR.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-04 13:28:29 +02:00
Amir Goldstein 007d1e8395 fsnotify: generalize handling of extra event flags
FS_EVENT_ON_CHILD gets a special treatment in fsnotify() because it is
not a flag specifying an event type, but rather an extra flags that may
be reported along with another event and control the handling of the
event by the backend.

FS_ISDIR is also an "extra flag" and not an "event type" and therefore
desrves the same treatment. With inotify/dnotify backends it was never
possible to set FS_ISDIR in mark masks, so it did not matter.
With fanotify backend, mark adding code jumps through hoops to avoid
setting the FS_ISDIR in the commulative object mask.

Separate the constant ALL_FSNOTIFY_EVENTS to ALL_FSNOTIFY_FLAGS and
ALL_FSNOTIFY_EVENTS, so the latter can be used to test for specific
event types.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-04 13:28:02 +02:00
Amir Goldstein 96a71f21ef fanotify: store fanotify_init() flags in group's fanotify_data
This averts the need to re-generate flags in fanotify_show_fdinfo()
and sets the scene for addition of more upcoming flags without growing
new members to the fanotify_data struct.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-09-27 15:29:00 +02:00
Amir Goldstein d54f4fba88 fanotify: add API to attach/detach super block mark
Add another mark type flag FAN_MARK_FILESYSTEM for add/remove/flush
of super block mark type.

A super block watch gets all events on the filesystem, regardless of
the mount from which the mark was added, unless an ignore mask exists
on either the inode or the mount where the event was generated.

Only one of FAN_MARK_MOUNT and FAN_MARK_FILESYSTEM mark type flags
may be provided to fanotify_mark() or no mark type flag for inode mark.

Cc: <linux-api@vger.kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-09-03 15:16:11 +02:00
Amir Goldstein 60f7ed8c7c fsnotify: send path type events to group with super block marks
Send events to group if super block mark mask matches the event
and unless the same group has an ignore mask on the vfsmount or
the inode on which the event occurred.

Soon, fanotify backend is going to support super block marks and
fanotify backend only supports path type events.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-09-03 15:14:04 +02:00
Amir Goldstein 1e6cb72399 fsnotify: add super block object type
Add the infrastructure to attach a mark to a super_block struct
and detach all attached marks when super block is destroyed.

This is going to be used by fanotify backend to setup super block
marks.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-09-03 15:14:01 +02:00
Amir Goldstein 9bdda4e9cf fsnotify: fix ignore mask logic in fsnotify()
Commit 92183a4289 ("fsnotify: fix ignore mask logic in
send_to_group()") acknoledges the use case of ignoring an event on
an inode mark, because of an ignore mask on a mount mark of the same
group (i.e. I want to get all events on this file, except for the events
that came from that mount).

This change depends on correctly merging the inode marks and mount marks
group lists, so that the mount mark ignore mask would be tested in
send_to_group(). Alas, the merging of the lists did not take into
account the case where event in question is not in the mask of any of
the mount marks.

To fix this, completely remove the tests for inode and mount event masks
from the lists merging code.

Fixes: 92183a4289 ("fsnotify: fix ignore mask logic in send_to_group")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-09-03 14:57:41 +02:00
Linus Torvalds f3f106dac0 \n
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Merge tag 'for_v4.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull misc fs fixes from Jan Kara:

 - make UDF to properly mount media created by Win7

 - make isofs to properly refuse devices with large physical block size

 - fix a Spectre gadget in quotactl(2)

 - fix a warning in fsnotify code hit by syzkaller

* tag 'for_v4.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: Fix mounting of Win7 created UDF filesystems
  udf: Remove dead code from udf_find_fileset()
  fs/quota: Fix spectre gadget in do_quotactl
  fs/quota: Replace XQM_MAXQUOTAS usage with MAXQUOTAS
  isofs: reject hardware sector size > 2048 bytes
  fsnotify: fix false positive warning on inode delete
2018-08-29 14:56:45 -07:00
Linus Torvalds 0214f46b3a Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull core signal handling updates from Eric Biederman:
 "It was observed that a periodic timer in combination with a
  sufficiently expensive fork could prevent fork from every completing.
  This contains the changes to remove the need for that restart.

  This set of changes is split into several parts:

   - The first part makes PIDTYPE_TGID a proper pid type instead
     something only for very special cases. The part starts using
     PIDTYPE_TGID enough so that in __send_signal where signals are
     actually delivered we know if the signal is being sent to a a group
     of processes or just a single process.

   - With that prep work out of the way the logic in fork is modified so
     that fork logically makes signals received while it is running
     appear to be received after the fork completes"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
  signal: Don't send signals to tasks that don't exist
  signal: Don't restart fork when signals come in.
  fork: Have new threads join on-going signal group stops
  fork: Skip setting TIF_SIGPENDING in ptrace_init_task
  signal: Add calculate_sigpending()
  fork: Unconditionally exit if a fatal signal is pending
  fork: Move and describe why the code examines PIDNS_ADDING
  signal: Push pid type down into complete_signal.
  signal: Push pid type down into __send_signal
  signal: Push pid type down into send_signal
  signal: Pass pid type into do_send_sig_info
  signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
  signal: Pass pid type into group_send_sig_info
  signal: Pass pid and pid type into send_sigqueue
  posix-timers: Noralize good_sigevent
  signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
  pid: Implement PIDTYPE_TGID
  pids: Move the pgrp and session pid pointers from task_struct to signal_struct
  kvm: Don't open code task_pid in kvm_vcpu_ioctl
  pids: Compute task_tgid using signal->leader_pid
  ...
2018-08-21 13:47:29 -07:00
Jan Kara d3bc0fa841 fsnotify: fix false positive warning on inode delete
When inode is getting deleted and someone else holds reference to a mark
attached to the inode, we just detach the connector from the inode. In
that case fsnotify_put_mark() called from fsnotify_destroy_marks() will
decide to recalculate mask for the inode and __fsnotify_recalc_mask()
will WARN about invalid connector type:

WARNING: CPU: 1 PID: 12015 at fs/notify/mark.c:139
__fsnotify_recalc_mask+0x2d7/0x350 fs/notify/mark.c:139

Actually there's no reason to warn about detached connector in
__fsnotify_recalc_mask() so just silently skip updating the mask in such
case.

Reported-by: syzbot+c34692a51b9a6ca93540@syzkaller.appspotmail.com
Fixes: 3ac70bfcde ("fsnotify: add helper to get mask from connector")
Signed-off-by: Jan Kara <jack@suse.cz>
2018-08-20 13:55:45 +02:00
Linus Torvalds 6ada4e2826 Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - a few misc things

 - a few Y2038 fixes

 - ntfs fixes

 - arch/sh tweaks

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits)
  mm/hmm.c: remove unused variables align_start and align_end
  fs/userfaultfd.c: remove redundant pointer uwq
  mm, vmacache: hash addresses based on pmd
  mm/list_lru: introduce list_lru_shrink_walk_irq()
  mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one()
  mm/list_lru.c: move locking from __list_lru_walk_one() to its caller
  mm/list_lru.c: use list_lru_walk_one() in list_lru_walk_node()
  mm, swap: make CONFIG_THP_SWAP depend on CONFIG_SWAP
  mm/sparse: delete old sparse_init and enable new one
  mm/sparse: add new sparse_init_nid() and sparse_init()
  mm/sparse: move buffer init/fini to the common place
  mm/sparse: use the new sparse buffer functions in non-vmemmap
  mm/sparse: abstract sparse buffer allocations
  mm/hugetlb.c: don't zero 1GiB bootmem pages
  mm, page_alloc: double zone's batchsize
  mm/oom_kill.c: document oom_lock
  mm/hugetlb: remove gigantic page support for HIGHMEM
  mm, oom: remove sleep from under oom_lock
  kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous()
  mm/cma: remove unsupported gfp_mask parameter from cma_alloc()
  ...
2018-08-17 16:49:31 -07:00
Shakeel Butt d46eb14b73 fs: fsnotify: account fsnotify metadata to kmemcg
Patch series "Directed kmem charging", v8.

The Linux kernel's memory cgroup allows limiting the memory usage of the
jobs running on the system to provide isolation between the jobs.  All
the kernel memory allocated in the context of the job and marked with
__GFP_ACCOUNT will also be included in the memory usage and be limited
by the job's limit.

The kernel memory can only be charged to the memcg of the process in
whose context kernel memory was allocated.  However there are cases
where the allocated kernel memory should be charged to the memcg
different from the current processes's memcg.  This patch series
contains two such concrete use-cases i.e.  fsnotify and buffer_head.

The fsnotify event objects can consume a lot of system memory for large
or unlimited queues if there is either no or slow listener.  The events
are allocated in the context of the event producer.  However they should
be charged to the event consumer.  Similarly the buffer_head objects can
be allocated in a memcg different from the memcg of the page for which
buffer_head objects are being allocated.

To solve this issue, this patch series introduces mechanism to charge
kernel memory to a given memcg.  In case of fsnotify events, the memcg
of the consumer can be used for charging and for buffer_head, the memcg
of the page can be charged.  For directed charging, the caller can use
the scope API memalloc_[un]use_memcg() to specify the memcg to charge
for all the __GFP_ACCOUNT allocations within the scope.

This patch (of 2):

A lot of memory can be consumed by the events generated for the huge or
unlimited queues if there is either no or slow listener.  This can cause
system level memory pressure or OOMs.  So, it's better to account the
fsnotify kmem caches to the memcg of the listener.

However the listener can be in a different memcg than the memcg of the
producer and these allocations happen in the context of the event
producer.  This patch introduces remote memcg charging API which the
producer can use to charge the allocations to the memcg of the listener.

There are seven fsnotify kmem caches and among them allocations from
dnotify_struct_cache, dnotify_mark_cache, fanotify_mark_cache and
inotify_inode_mark_cachep happens in the context of syscall from the
listener.  So, SLAB_ACCOUNT is enough for these caches.

The objects from fsnotify_mark_connector_cachep are not accounted as
they are small compared to the notification mark or events and it is
unclear whom to account connector to since it is shared by all events
attached to the inode.

The allocations from the event caches happen in the context of the event
producer.  For such caches we will need to remote charge the allocations
to the listener's memcg.  Thus we save the memcg reference in the
fsnotify_group structure of the listener.

This patch has also moved the members of fsnotify_group to keep the size
same, at least for 64 bit build, even with additional member by filling
the holes.

[shakeelb@google.com: use GFP_KERNEL_ACCOUNT rather than open-coding it]
  Link: http://lkml.kernel.org/r/20180702215439.211597-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20180627191250.209150-2-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Eric W. Biederman 019191342f signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
When f_setown is called a pid and a pid type are stored.  Replace the use
of PIDTYPE_PID with PIDTYPE_TGID as PIDTYPE_TGID goes to the entire thread
group.  Replace the use of PIDTYPE_MAX with PIDTYPE_PID as PIDTYPE_PID now
is only for a thread.

Update the users of __f_setown to use PIDTYPE_TGID instead of
PIDTYPE_PID.

For now the code continues to capture task_pid (when task_tgid would
really be appropriate), and iterate on PIDTYPE_PID (even when type ==
PIDTYPE_TGID) out of an abundance of caution to preserve existing
behavior.

Oleg Nesterov suggested using the test to ensure we use PIDTYPE_PID
for tgid lookup also be used to avoid taking the tasklist lock.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Eric W. Biederman 7a36094d61 pids: Compute task_tgid using signal->leader_pid
The cost is the the same and this removes the need
to worry about complications that come from de_thread
and group_leader changing.

__task_pid_nr_ns has been updated to take advantage of this change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Henry Wilson 4d97f7d53d inotify: Add flag IN_MASK_CREATE for inotify_add_watch()
The flag IN_MASK_CREATE is introduced as a flag for inotiy_add_watch()
which prevents inotify from modifying any existing watches when invoked.
If the pathname specified in the call has a watched inode associated
with it and IN_MASK_CREATE is specified, fail with an errno of EEXIST.

Use of IN_MASK_CREATE with IN_MASK_ADD is reserved for future use and
will return EINVAL.

RATIONALE

In the current implementation, there is no way to prevent
inotify_add_watch() from modifying existing watch descriptors. Even if
the caller keeps a record of all watch descriptors collected, this is
only sufficient to detect that an existing watch descriptor may have
been modified.

The assumption that a particular path will map to the same inode over
multiple calls to inotify_add_watch() cannot be made as files can be
renamed or deleted.  It is also not possible to assume that two distinct
paths do no map to the same inode, due to hard-links or a dereferenced
symbolic link. Further uses of inotify_add_watch() to revert the change
may cause other watch descriptors to be modified or created, merely
compunding the problem. There is currently no system call such as
inotify_modify_watch() to explicity modify a watch descriptor, which
would be able to revert unwanted changes. Thus the caller cannot
guarantee to be able to revert any changes to existing watch decriptors.

Additionally the caller cannot assume that the events that are
associated with a watch descriptor are within the set requested, as any
future calls to inotify_add_watch() may unintentionally modify a watch
descriptor's mask. Thus it cannot currently be guaranteed that a watch
descriptor will only generate events which have been requested. The
program must filter events which come through its watch descriptor to
within its expected range.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Henry Wilson <henry.wilson@acentic.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-06-27 19:21:25 +02:00
Amir Goldstein eaa2c6b0c9 fanotify: factor out helpers to add/remove mark
Factor out helpers fanotify_add_mark() and fanotify_remove_mark()
to reduce duplicated code.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-06-27 13:45:12 +02:00
Amir Goldstein 3ac70bfcde fsnotify: add helper to get mask from connector
Use a helper to get the mask from the object (i.e. i_fsnotify_mask)
to generalize code of add/remove inode/vfsmount mark.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-06-27 13:45:07 +02:00
Amir Goldstein 36f10f55ff fsnotify: let connector point to an abstract object
Make the code to attach/detach a connector to object more generic
by letting the fsnotify connector point to an abstract fsnotify_connp_t.
Code that needs to dereference an inode or mount object now uses the
helpers fsnotify_conn_{inode,mount}.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-06-27 13:45:05 +02:00
Amir Goldstein b812a9f589 fsnotify: pass connp and object type to fsnotify_add_mark()
Instead of passing inode and vfsmount arguments to fsnotify_add_mark()
and its _locked variant, pass an abstract object pointer and the object
type.

The helpers fsnotify_obj_{inode,mount} are added to get the concrete
object pointer from abstract object pointer.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-06-27 13:45:03 +02:00
Amir Goldstein 9b6e543450 fsnotify: use typedef fsnotify_connp_t for brevity
The object marks manipulation functions fsnotify_destroy_marks()
fsnotify_find_mark() and their helpers take an argument of type
struct fsnotify_mark_connector __rcu ** to dereference the connector
pointer. use a typedef to describe this type for brevity.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-06-27 13:44:59 +02:00
Amir Goldstein b249f5be61 fsnotify: add fsnotify_add_inode_mark() wrappers
Before changing the arguments of the functions fsnotify_add_mark()
and fsnotify_add_mark_locked(), convert most callers to use a wrapper.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18 14:58:22 +02:00
Amir Goldstein 837a393438 fanotify: generalize fanotify_should_send_event()
Use fsnotify_foreach_obj_type macros to generalize the code that filters
events by marks mask and ignored_mask.

This is going to be used for adding mark of super block object type.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18 14:58:22 +02:00
Amir Goldstein 3dca1a7494 fsnotify: generalize send_to_group()
Use fsnotify_foreach_obj_type macros to generalize the code that filters
events by marks mask and ignored_mask.

This is going to be used for adding mark of super block object type.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18 14:58:22 +02:00
Amir Goldstein 47d9c7cc45 fsnotify: generalize iteration of marks by object type
Make some code that handles marks of object types inode and vfsmount
generic, so it can handle other object types.

Introduce fsnotify_foreach_obj_type macro to iterate marks by object type
and fsnotify_iter_{should|set}_report_type macros to set/test report_mask.

This is going to be used for adding mark of another object type
(super block mark).

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18 14:58:22 +02:00
Amir Goldstein d9a6f30bb8 fsnotify: introduce marks iteration helpers
Introduce helpers fsnotify_iter_select_report_types() and
fsnotify_iter_next() to abstract the inode/vfsmount marks merged
list iteration.

This is a preparation patch before generalizing mark list
iteration to more mark object types (i.e. super block marks).

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18 14:58:22 +02:00
Amir Goldstein 5b0457ad02 fsnotify: remove redundant arguments to handle_event()
inode_mark and vfsmount_mark arguments are passed to handle_event()
operation as function arguments as well as on iter_info struct.
The difference is that iter_info struct may contain marks that should
not be handled and are represented as NULL arguments to inode_mark or
vfsmount_mark.

Instead of passing the inode_mark and vfsmount_mark arguments, add
a report_mask member to iter_info struct to indicate which marks should
be handled, versus marks that should only be kept alive during user
wait.

This change is going to be used for passing more mark types
with handle_event() (i.e. super block marks).

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18 14:58:22 +02:00
Amir Goldstein d6f7b98bc8 fsnotify: use type id to identify connector object type
An fsnotify_mark_connector is referencing a single type of object
(either inode or vfsmount). Instead of storing a type mask in
connector->flags, store a single type id in connector->type to
identify the type of object.

When a connector object is detached from the object, its type is set
to FSNOTIFY_OBJ_TYPE_DETACHED and this object is not going to be
reused.

The function fsnotify_clear_marks_by_group() is the only place where
type mask was used, so use type flags instead of type id to this
function.

This change is going to be more convenient when adding a new object
type (super block).

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-05-18 14:58:22 +02:00
Amir Goldstein 92183a4289 fsnotify: fix ignore mask logic in send_to_group()
The ignore mask logic in send_to_group() does not match the logic
in fanotify_should_send_event(). In the latter, a vfsmount mark ignore
mask precedes an inode mark mask and in the former, it does not.

That difference may cause events to be sent to fanotify backend for no
reason. Fix the logic in send_to_group() to match that of
fanotify_should_send_event().

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-04-13 15:52:49 +02:00
Amir Goldstein 54a307ba8d fanotify: fix logic of events on child
When event on child inodes are sent to the parent inode mark and
parent inode mark was not marked with FAN_EVENT_ON_CHILD, the event
will not be delivered to the listener process. However, if the same
process also has a mount mark, the event to the parent inode will be
delivered regadless of the mount mark mask.

This behavior is incorrect in the case where the mount mark mask does
not contain the specific event type. For example, the process adds
a mark on a directory with mask FAN_MODIFY (without FAN_EVENT_ON_CHILD)
and a mount mark with mask FAN_CLOSE_NOWRITE (without FAN_ONDIR).

A modify event on a file inside that directory (and inside that mount)
should not create a FAN_MODIFY event, because neither of the marks
requested to get that event on the file.

Fixes: 1968f5eed5 ("fanotify: use both marks when possible")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-04-09 16:30:14 +02:00
Linus Torvalds be88751f32 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull misc filesystem updates from Jan Kara:
 "udf, ext2, quota, fsnotify fixes & cleanups:

   - udf fixes for handling of media without uid/gid

   - udf fixes for some corner cases in parsing of volume recognition
     sequence

   - improvements of fsnotify handling of ENOMEM

   - new ioctl to allow setting of watch descriptor id for inotify (for
     checkpoint - restart)

   - small ext2, reiserfs, quota cleanups"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: Kill an unused extern entry form quota.h
  reiserfs: Remove VLA from fs/reiserfs/reiserfs.h
  udf: fix potential refcnt problem of nls module
  ext2: change return code to -ENOMEM when failing memory allocation
  udf: Do not mark possibly inconsistent filesystems as closed
  fsnotify: Let userspace know about lost events due to ENOMEM
  fanotify: Avoid lost events due to ENOMEM for unlimited queues
  udf: Remove never implemented mount options
  udf: Update mount option documentation
  udf: Provide saner default for invalid uid / gid
  udf: Clean up handling of invalid uid/gid
  udf: Apply uid/gid mount options also to new inodes & chown
  udf: Ignore [ug]id=ignore mount options
  udf: Fix handling of Partition Descriptors
  udf: Unify common handling of descriptors
  udf: Convert descriptor index definitions to enum
  udf: Allow volume descriptor sequence to be terminated by unrecorded block
  udf: Simplify handling of Volume Descriptor Pointers
  udf: Fix off-by-one in volume descriptor sequence length
  inotify: Extend ioctl to allow to request id of new watch descriptor
2018-04-05 19:17:50 -07:00
Dominik Brodowski 183caa3c86 fanotify: add do_fanotify_mark() helper; remove in-kernel call to syscall
Using the fs-internal do_fanotify_mark() helper allows us to get rid of
the fs-internal call to the sys_fanotify_mark() syscall.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Acked-by: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:45 +02:00
Dominik Brodowski d0d89d1ed3 inotify: add do_inotify_init() helper; remove in-kernel call to syscall
Using the inotify-internal do_inotify_init() helper allows us to get rid
of the in-kernel call to sys_inotify_init1() syscall.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Acked-by: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:45 +02:00
Jan Kara 7b1f641776 fsnotify: Let userspace know about lost events due to ENOMEM
Currently if notification event is lost due to event allocation failing
we ENOMEM, we just silently continue (except for fanotify permission
events where we deny the access). This is undesirable as userspace has
no way of knowing whether the notifications it got are complete or not.
Treat lost events due to ENOMEM the same way as lost events due to queue
overflow so that userspace knows something bad happened and it likely
needs to rescan the filesystem.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-02-27 10:25:33 +01:00
Jan Kara 1f5eaa9001 fanotify: Avoid lost events due to ENOMEM for unlimited queues
Fanotify queues of unlimited length do not expect events can be lost.
Since these queues are used for system auditing and other security
related tasks, loosing events can even have security implications.
Currently, since the allocation is small (32-bytes), it cannot fail
however when we start accounting events in memcgs, allocation can start
failing. So avoid loosing events due to failure to allocate memory by
making event allocation use __GFP_NOFAIL.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-02-27 10:25:33 +01:00
Kirill Tkhai e1603b6eff inotify: Extend ioctl to allow to request id of new watch descriptor
Watch descriptor is id of the watch created by inotify_add_watch().
It is allocated in inotify_add_to_idr(), and takes the numbers
starting from 1. Every new inotify watch obtains next available
number (usually, old + 1), as served by idr_alloc_cyclic().

CRIU (Checkpoint/Restore In Userspace) project supports inotify
files, and restores watched descriptors with the same numbers,
they had before dump. Since there was no kernel support, we
had to use cycle to add a watch with specific descriptor id:

	while (1) {
		int wd;

		wd = inotify_add_watch(inotify_fd, path, mask);
		if (wd < 0) {
			break;
		} else if (wd == desired_wd_id) {
			ret = 0;
			break;
		}

		inotify_rm_watch(inotify_fd, wd);
	}

(You may find the actual code at the below link:
 https://github.com/checkpoint-restore/criu/blob/v3.7/criu/fsnotify.c#L577)

The cycle is suboptiomal and very expensive, but since there is no better
kernel support, it was the only way to restore that. Happily, we had met
mostly descriptors with small id, and this approach had worked somehow.

But recent time containers with inotify with big watch descriptors
begun to come, and this way stopped to work at all. When descriptor id
is something about 0x34d71d6, the restoring process spins in busy loop
for a long time, and the restore hungs and delay of migration from node
to node could easily be watched.

This patch aims to solve this problem. It introduces new ioctl
INOTIFY_IOC_SETNEXTWD, which allows to request the number of next created
watch descriptor from userspace. It simply calls idr_set_cursor() primitive
to populate idr::idr_next, so that next idr_alloc_cyclic() allocation
will return this id, if it is not occupied. This is the way which is
used to restore some other resources from userspace. For example,
/proc/sys/kernel/ns_last_pid works the same for task pids.

The new code is under CONFIG_CHECKPOINT_RESTORE #define, so small system
may exclude it.

v2: Use INT_MAX instead of custom definition of max id,
as IDR subsystem guarantees id is between 0 and INT_MAX.

CC: Jan Kara <jack@suse.cz>
CC: Matthew Wilcox <willy@infradead.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2018-02-14 11:16:28 +01:00
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Linus Torvalds 168fe32a07 Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull poll annotations from Al Viro:
 "This introduces a __bitwise type for POLL### bitmap, and propagates
  the annotations through the tree. Most of that stuff is as simple as
  'make ->poll() instances return __poll_t and do the same to local
  variables used to hold the future return value'.

  Some of the obvious brainos found in process are fixed (e.g. POLLIN
  misspelled as POLL_IN). At that point the amount of sparse warnings is
  low and most of them are for genuine bugs - e.g. ->poll() instance
  deciding to return -EINVAL instead of a bitmap. I hadn't touched those
  in this series - it's large enough as it is.

  Another problem it has caught was eventpoll() ABI mess; select.c and
  eventpoll.c assumed that corresponding POLL### and EPOLL### were
  equal. That's true for some, but not all of them - EPOLL### are
  arch-independent, but POLL### are not.

  The last commit in this series separates userland POLL### values from
  the (now arch-independent) kernel-side ones, converting between them
  in the few places where they are copied to/from userland. AFAICS, this
  is the least disruptive fix preserving poll(2) ABI and making epoll()
  work on all architectures.

  As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
  it will trigger only on what would've triggered EPOLLWRBAND on other
  architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
  at all on sparc. With this patch they should work consistently on all
  architectures"

* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  make kernel-side POLL... arch-independent
  eventpoll: no need to mask the result of epi_item_poll() again
  eventpoll: constify struct epoll_event pointers
  debugging printk in sg_poll() uses %x to print POLL... bitmap
  annotate poll(2) guts
  9p: untangle ->poll() mess
  ->si_band gets POLL... bitmap stored into a user-visible long field
  ring_buffer_poll_wait() return value used as return value of ->poll()
  the rest of drivers/*: annotate ->poll() instances
  media: annotate ->poll() instances
  fs: annotate ->poll() instances
  ipc, kernel, mm: annotate ->poll() instances
  net: annotate ->poll() instances
  apparmor: annotate ->poll() instances
  tomoyo: annotate ->poll() instances
  sound: annotate ->poll() instances
  acpi: annotate ->poll() instances
  crypto: annotate ->poll() instances
  block: annotate ->poll() instances
  x86: annotate ->poll() instances
  ...
2018-01-30 17:58:07 -08:00
Al Viro 076ccb76e1 fs: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:20:05 -05:00
Linus Torvalds 1751e8a6cb Rename superblock flags (MS_xyz -> SB_xyz)
This is a pure automated search-and-replace of the internal kernel
superblock flags.

The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.

Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.

The script to do this was:

    # places to look in; re security/*: it generally should *not* be
    # touched (that stuff parses mount(2) arguments directly), but
    # there are two places where we really deal with superblock flags.
    FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
            include/linux/fs.h include/uapi/linux/bfs_fs.h \
            security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
    # the list of MS_... constants
    SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
          DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
          POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
          I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
          ACTIVE NOUSER"

    SED_PROG=
    for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done

    # we want files that contain at least one of MS_...,
    # with fs/namespace.c and fs/pnode.c excluded.
    L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')

    for f in $L; do sed -i $f $SED_PROG; done

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27 13:05:09 -08:00
Linus Torvalds 9682b3dea2 Merge branch 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "The usual rocket-science from trivial tree for 4.15"

* 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  MAINTAINERS: relinquish kconfig
  MAINTAINERS: Update my email address
  treewide: Fix typos in Kconfig
  kfifo: Fix comments
  init/Kconfig: Fix module signing document location
  misc: ibmasm: Return error on error path
  HID: logitech-hidpp: fix mistake in printk, "feeback" -> "feedback"
  MAINTAINERS: Correct path to uDraw PS3 driver
  tracing: Fix doc mistakes in trace sample
  tracing: Kconfig text fixes for CONFIG_HWLAT_TRACER
  MIPS: Alchemy: Remove reverted CONFIG_NETLINK_MMAP from db1xxx_defconfig
  mm/huge_memory.c: fixup grammar in comment
  lib/xz: Add fall-through comments to a switch statement
2017-11-15 10:14:11 -08:00
Linus Torvalds f14fc0ccee Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull quota, ext2, isofs and udf fixes from Jan Kara:

 - two small quota error handling fixes

 - two isofs fixes for architectures with signed char

 - several udf block number overflow and signedness fixes

 - ext2 rework of mount option handling to avoid GFP_KERNEL allocation
   with spinlock held

 - ... it also contains a patch to implement auditing of responses to
   fanotify permission events. That should have been in the fanotify
   pull request but I mistakenly merged that patch into a wrong branch
   and noticed only now at which point I don't think it's worth rebasing
   and redoing.

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: be aware of error from dquot_initialize
  quota: fix potential infinite loop
  isofs: use unsigned char types consistently
  isofs: fix timestamps beyond 2027
  udf: Fix some sign-conversion warnings
  udf: Fix signed/unsigned format specifiers
  udf: Fix 64-bit sign extension issues affecting blocks > 0x7FFFFFFF
  udf: Remove some outdate references from documentation
  udf: Avoid overflow when session starts at large offset
  ext2: Fix possible sleep in atomic during mount option parsing
  ext2: Parse mount options into a dedicated structure
  audit: Record fanotify access control decisions
2017-11-14 14:13:11 -08:00
Linus Torvalds 23281c8034 Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify updates from Jan Kara:

 - fixes of use-after-tree issues when handling fanotify permission
   events from Miklos

 - refcount_t conversions from Elena

 - fixes of ENOMEM handling in dnotify and fsnotify from me

* 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fsnotify: convert fsnotify_mark.refcnt from atomic_t to refcount_t
  fanotify: clean up CONFIG_FANOTIFY_ACCESS_PERMISSIONS ifdefs
  fsnotify: clean up fsnotify()
  fanotify: fix fsnotify_prepare_user_wait() failure
  fsnotify: fix pinning group in fsnotify_prepare_user_wait()
  fsnotify: pin both inode and vfsmount mark
  fsnotify: clean up fsnotify_prepare/finish_user_wait()
  fsnotify: convert fsnotify_group.refcnt from atomic_t to refcount_t
  fsnotify: Protect bail out path of fsnotify_add_mark_locked() properly
  dnotify: Handle errors from fsnotify_add_mark_locked() in fcntl_dirnotify()
2017-11-14 14:08:20 -08:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Elena Reshetova ab97f87325 fsnotify: convert fsnotify_mark.refcnt from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable fsnotify_mark.refcnt is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-10-31 17:54:56 +01:00