linux-toradex.git/fs/notify, branch v3.16

inotify: convert use of typedef ctl_table to struct ctl_table

2014-06-06T23:08:16+00:00

This typedef is unnecessary and should just be removed.

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

fanotify: check file flags passed in fanotify_init

2014-06-04T23:53:52+00:00

Without this patch fanotify_init does not validate the value passed in
event_f_flags.

When a fanotify event is read from the fanotify file descriptor a new
file descriptor is created where file.f_flags = event_f_flags.

Internal and external open flags are stored together in field f_flags of
struct file.  Hence, an application might create file descriptors with
internal flags like FMODE_EXEC, FMODE_NOCMTIME set.

Jan Kara and Eric Paris both aggreed that this is a bug and the value of
event_f_flags should be checked:
  https://lkml.org/lkml/2014/4/29/522
  https://lkml.org/lkml/2014/4/29/539

This updated patch version considers the comments by Michael Kerrisk in
  https://lkml.org/lkml/2014/5/4/10

With the patch the value of event_f_flags is checked.
When specifying an invalid value error EINVAL is returned.

Internal flags are disallowed.

File creation flags are disallowed:
O_CREAT, O_DIRECTORY, O_EXCL, O_NOCTTY, O_NOFOLLOW, O_TRUNC, and O_TTY_INIT.

Flags which do not make sense with fanotify are disallowed:
__O_TMPFILE, O_PATH, FASYNC, and O_DIRECT.

This leaves us with the following allowed values:

O_RDONLY, O_WRONLY, O_RDWR are basic functionality. The are stored in the
bits given by O_ACCMODE.

O_APPEND is working as expected. The value might be useful in a logging
application which appends the current status each time the log is opened.

O_LARGEFILE is needed for files exceeding 4GB on 32bit systems.

O_NONBLOCK may be useful when monitoring slow devices like tapes.

O_NDELAY is equal to O_NONBLOCK except for platform parisc.
To avoid code breaking on parisc either both flags should be
allowed or none. The patch allows both.

__O_SYNC and O_DSYNC may be used to avoid data loss on power disruption.

O_NOATIME may be useful to reduce disk activity.

O_CLOEXEC may be useful, if separate processes shall be used to scan files.

Once this patch is accepted, the fanotify_init.2 manpage has to be updated.

Signed-off-by: Heinrich Schuchardt 
Reviewed-by: Jan Kara 
Cc: Michael Kerrisk 
Cc: Valdis Kletnieks 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/notify/fanotify/fanotify_user.c: fix FAN_MARK_FLUSH flag checking

2014-06-04T23:53:52+00:00

If fanotify_mark is called with illegal value of arguments flags and
marks it usually returns EINVAL.

When fanotify_mark is called with FAN_MARK_FLUSH the argument flags is
not checked for irrelevant flags like FAN_MARK_IGNORED_MASK.

The patch removes this inconsistency.

If an irrelevant flag is set error EINVAL is returned.

Signed-off-by: Heinrich Schuchardt 
Acked-by: Michael Kerrisk 
Acked-by: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/notify/mark.c: trivial cleanup

2014-06-04T23:53:52+00:00

Do not initialize private_destroy_list twice.  list_replace_init()
already takes care of initializing private_destroy_list.  We don't need
to initialize it with LIST_HEAD() beforehand.

Signed-off-by: David Cohen 
Cc: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: FAN_MARK_FLUSH: avoid having to provide a fake/invalid fd and path

2014-06-04T23:53:52+00:00

Originally from Tvrtko Ursulin (https://lkml.org/lkml/2011/1/12/112)

Avoid having to provide a fake/invalid fd and path when flushing marks

Currently for a group to flush marks it has set it needs to provide a
fake or invalid (but resolvable) file descriptor and path when calling
fanotify_mark.  This patch pulls the flush handling a bit up so file
descriptor and path are completely ignored when flushing.

I reworked the patch to be applicable again (the signature of
fanotify_mark has changed since Tvrtko's work).

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

fanotify: fix -EOVERFLOW with large files on 64-bit

2014-05-06T20:04:59+00:00

On 64-bit systems, O_LARGEFILE is automatically added to flags inside
the open() syscall (also openat(), blkdev_open(), etc).  Userspace
therefore defines O_LARGEFILE to be 0 - you can use it, but it's a
no-op.  Everything should be O_LARGEFILE by default.

But: when fanotify does create_fd() it uses dentry_open(), which skips
all that.  And userspace can't set O_LARGEFILE in fanotify_init()
because it's defined to 0.  So if fanotify gets an event regarding a
large file, the read() will just fail with -EOVERFLOW.

This patch adds O_LARGEFILE to fanotify_init()'s event_f_flags on 64-bit
systems, using the same test as open()/openat()/etc.

Addresses https://bugzilla.redhat.com/show_bug.cgi?id=696821

Signed-off-by: Will Woods 
Acked-by: Eric Paris 
Reviewed-by: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: move unrelated handling from copy_event_to_user()

2014-04-03T23:20:51+00:00

Move code moving event structure to access_list from copy_event_to_user()
to fanotify_read() where it is more logical (so that we can immediately
see in the main loop that we either move the event to a different list
or free it).  Also move special error handling for permission events
from copy_event_to_user() to the main loop to have it in one place with
error handling for normal events.  This makes copy_event_to_user()
really only copy the event to user without any side effects.

Signed-off-by: Jan Kara 
Cc: Eric Paris 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: reorganize loop in fanotify_read()

2014-04-03T23:20:51+00:00

Swap the error / "read ok" branches in the main loop of fanotify_read().
We will grow the "read ok" part in the next patch and this makes the
indentation easier.  Also it is more common to have error conditions
inside an 'if' instead of the fast path.

Signed-off-by: Jan Kara 
Cc: Eric Paris 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: convert access_mutex to spinlock

2014-04-03T23:20:51+00:00

access_mutex is used only to guard operations on access_list.  There's
no need for sleeping within this lock so just make a spinlock out of it.

Signed-off-by: Jan Kara 
Cc: Eric Paris 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fanotify: use fanotify event structure for permission response processing

2014-04-03T23:20:51+00:00

Currently, fanotify creates new structure to track the fact that
permission event has been reported to userspace and someone is waiting
for a response to it.  As event structures are now completely in the
hands of each notification framework, we can use the event structure for
this tracking instead of allocating a new structure.

Since this makes the event structures for normal events and permission
events even more different and the structures have different lifetime
rules, we split them into two separate structures (where permission
event structure contains the structure for a normal event).  This makes
normal events 8 bytes smaller and the code a tad bit cleaner.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Jan Kara 
Cc: Eric Paris 
Cc: Al Viro 
Cc: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds