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2015-03-12fanotify: fix event filtering with FAN_ONDIR setSuzuki K. Poulose1-1/+2
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 <suzuki.poulose@arm.com> Tested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-22fanotify: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversionsDavid Howells1-1/+1
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 <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)David Howells1-3/+3
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 <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-10fanotify: don't set FAN_ONDIR implicitly on a marks ignored maskLino Sanfilippo1-1/+1
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 <LinoSanfilippo@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06fanotify: fix double free of pending permission eventsJan Kara1-1/+8
Commit 85816794240b ("fanotify: Fix use after free for permission events") introduced a double free issue for permission events which are pending in group's notification queue while group is being destroyed. These events are freed from fanotify_handle_event() but they are not removed from groups notification queue and thus they get freed again from fsnotify_flush_notify(). Fix the problem by removing permission events from notification queue before freeing them if we skip processing access response. Also expand comments in fanotify_release() to explain group shutdown in detail. Fixes: 85816794240b9659e66e4d9b0df7c6e814e5f603 Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Douglas Leeder <douglas.leeder@sophos.com> Tested-by: Douglas Leeder <douglas.leeder@sophos.com> Reported-by: Heinrich Schuchard <xypron.glpk@gmx.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06fsnotify: rename event handling functionsJan Kara1-1/+1
Rename fsnotify_add_notify_event() to fsnotify_add_event() since the "notify" part is duplicit. Rename fsnotify_remove_notify_event() and fsnotify_peek_notify_event() to fsnotify_remove_first_event() and fsnotify_peek_first_event() respectively since "notify" part is duplicit and they really look at the first event in the queue. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03fanotify: use fanotify event structure for permission response processingJan Kara1-18/+45
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 <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-25fanotify: Handle overflow in case of permission eventsJan Kara1-2/+4
If the event queue overflows when we are handling permission event, we will never get response from userspace. So we must avoid waiting for it. Change fsnotify_add_notify_event() to return whether overflow has happened so that we can detect it in fanotify_handle_event() and act accordingly. Signed-off-by: Jan Kara <jack@suse.cz>
2014-02-18inotify: Fix reporting of cookies for inotify eventsJan Kara1-1/+1
My rework of handling of notification events (namely commit 7053aee26a35 "fsnotify: do not share events between notification groups") broke sending of cookies with inotify events. We didn't propagate the value passed to fsnotify() properly and passed 4 uninitialized bytes to userspace instead (so it is also an information leak). Sadly I didn't notice this during my testing because inotify cookies aren't used very much and LTP inotify tests ignore them. Fix the problem by passing the cookie value properly. Fixes: 7053aee26a3548ebaba046ae2e52396ccf56ac6c Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-29fanotify: Fix use after free for permission eventsJan Kara1-1/+4
Currently struct fanotify_event_info has been destroyed immediately after reporting its contents to userspace. However that is wrong for permission events because those need to stay around until userspace provides response which is filled back in fanotify_event_info. So change to code to free permission events only after we have got the response from userspace. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-29fsnotify: Do not return merged event from fsnotify_add_notify_event()Jan Kara1-11/+7
The event returned from fsnotify_add_notify_event() cannot ever be used safely as the event may be freed by the time the function returns (after dropping notification_mutex). So change the prototype to just return whether the event was added or merged into some existing event. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-29fanotify: Fix use after free in mask checkingJan Kara1-10/+11
We cannot use the event structure returned from fsnotify_add_notify_event() because that event can be freed by the time that function returns. Use the mask argument passed into the event handler directly instead. This also fixes a possible problem when we could unnecessarily wait for permission response for a normal fanotify event which got merged with a permission event. We also disallow merging of permission event with any other event so that we know the permission event which we just created is the one on which we should wait for permission response. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Reported-and-tested-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Jan Kara <jack@suse.cz>
2014-01-21fsnotify: remove pointless NULL initializersJan Kara1-1/+0
We usually rely on the fact that struct members not specified in the initializer are set to NULL. So do that with fsnotify function pointers as well. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> 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>
2014-01-21fsnotify: remove .should_send_event callbackJan Kara1-8/+10
After removing event structure creation from the generic layer there is no reason for separate .should_send_event and .handle_event callbacks. So just remove the first one. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> 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>
2014-01-21fsnotify: do not share events between notification groupsJan Kara1-107/+104
Currently fsnotify framework creates one event structure for each notification event and links this event into all interested notification groups. This is done so that we save memory when several notification groups are interested in the event. However the need for event structure shared between inotify & fanotify bloats the event structure so the result is often higher memory consumption. Another problem is that fsnotify framework keeps path references with outstanding events so that fanotify can return open file descriptors with its events. This has the undesirable effect that filesystem cannot be unmounted while there are outstanding events - a regression for inotify compared to a situation before it was converted to fsnotify framework. For fanotify this problem is hard to avoid and users of fanotify should kind of expect this behavior when they ask for file descriptors from notified files. This patch changes fsnotify and its users to create separate event structure for each group. This allows for much simpler code (~400 lines removed by this patch) and also smaller event structures. For example on 64-bit system original struct fsnotify_event consumes 120 bytes, plus additional space for file name, additional 24 bytes for second and each subsequent group linking the event, and additional 32 bytes for each inotify group for private data. After the conversion inotify event consumes 48 bytes plus space for file name which is considerably less memory unless file names are long and there are several groups interested in the events (both of which are uncommon). Fanotify event fits in 56 bytes after the conversion (fanotify doesn't care about file names so its events don't have to have it allocated). A win unless there are four or more fanotify groups interested in the event. The conversion also solves the problem with unmount when only inotify is used as we don't have to grab path references for inotify events. [hughd@google.com: fanotify: fix corruption preventing startup] Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20Merge branch 'for-next' of git://git.infradead.org/users/eparis/notifyLinus Torvalds1-0/+6
Pull filesystem notification updates from Eric Paris: "This pull mostly is about locking changes in the fsnotify system. By switching the group lock from a spin_lock() to a mutex() we can now hold the lock across things like iput(). This fixes a problem involving unmounting a fs and having inodes be busy, first pointed out by FAT, but reproducible with tmpfs. This also restores signal driven I/O for inotify, which has been broken since about 2.6.32." Ugh. I *hate* the timing of this. It was rebased after the merge window opened, and then left to sit with the pull request coming the day before the merge window closes. That's just crap. But apparently the patches themselves have been around for over a year, just gathering dust, so now it's suddenly critical. Fixed up semantic conflict in fs/notify/fdinfo.c as per Stephen Rothwell's fixes from -next. * 'for-next' of git://git.infradead.org/users/eparis/notify: inotify: automatically restart syscalls inotify: dont skip removal of watch descriptor if creation of ignored event failed fanotify: dont merge permission events fsnotify: make fasync generic for both inotify and fanotify fsnotify: change locking order fsnotify: dont put marks on temporary list when clearing marks by group fsnotify: introduce locked versions of fsnotify_add_mark() and fsnotify_remove_mark() fsnotify: pass group to fsnotify_destroy_mark() fsnotify: use a mutex instead of a spinlock to protect a groups mark list fanotify: add an extra flag to mark_remove_from_mask that indicates wheather a mark should be destroyed fsnotify: take groups mark_lock before mark lock fsnotify: use reference counting for groups fsnotify: introduce fsnotify_get_group() inotify, fanotify: replace fsnotify_put_group() with fsnotify_destroy_group()
2012-12-11fanotify: dont merge permission eventsLino Sanfilippo1-0/+6
Boyd Yang reported a problem for the case that multiple threads of the same thread group are waiting for a reponse for a permission event. In this case it is possible that some of the threads are never woken up, even if the response for the event has been received (see http://marc.info/?l=linux-kernel&m=131822913806350&w=2). The reason is that we are currently merging permission events if they belong to the same thread group. But we are not prepared to wake up more than one waiter for each event. We do wait_event(group->fanotify_data.access_waitq, event->response || atomic_read(&group->fanotify_data.bypass_perm)); and after that event->response = 0; which is the reason that even if we woke up all waiters for the same event some of them may see event->response being already set 0 again, then go back to sleep and block forever. With this patch we avoid that more than one thread is waiting for a response by not merging permission events for the same thread group any more. Reported-by: Boyd Yang <boyd.yang@gmail.com> Signed-off-by: Lino Sanfilippo <LinoSanfilipp@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2012-11-09fanotify: fix missing breakEric Paris1-0/+1
Anders Blomdell noted in 2010 that Fanotify lost events and provided a test case. Eric Paris confirmed it was a bug and posted a fix to the list https://groups.google.com/forum/?fromgroups=#!topic/linux.kernel/RrJfTfyW2BE but never applied it. Repeated attempts over time to actually get him to apply it have never had a reply from anyone who has raised it So apply it anyway Signed-off-by: Alan Cox <alan@linux.intel.com> Reported-by: Anders Blomdell <anders.blomdell@control.lth.se> Cc: Eric Paris <eparis@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-07fanotify: on group destroy allow all waiters to bypass permission checkLino Sanfilippo1-1/+5
When fanotify_release() is called, there may still be processes waiting for access permission. Currently only processes for which an event has already been queued into the groups access list will be woken up. Processes for which no event has been queued will continue to sleep and thus cause a deadlock when fsnotify_put_group() is called. Furthermore there is a race allowing further processes to be waiting on the access wait queue after wake_up (if they arrive before clear_marks_by_group() is called). This patch corrects this by setting a flag to inform processes that the group is about to be destroyed and thus not to wait for access permission. [additional changelog from eparis] Lets think about the 4 relevant code paths from the PoV of the 'operator' 'listener' 'responder' and 'closer'. Where operator is the process doing an action (like open/read) which could require permission. Listener is the task (or in this case thread) slated with reading from the fanotify file descriptor. The 'responder' is the thread responsible for responding to access requests. 'Closer' is the thread attempting to close the fanotify file descriptor. The 'operator' is going to end up in: fanotify_handle_event() get_response_from_access() (THIS BLOCKS WAITING ON USERSPACE) The 'listener' interesting code path fanotify_read() copy_event_to_user() prepare_for_access_response() (THIS CREATES AN fanotify_response_event) The 'responder' code path: fanotify_write() process_access_response() (REMOVE A fanotify_response_event, SET RESPONSE, WAKE UP 'operator') The 'closer': fanotify_release() (SUPPOSED TO CLEAN UP THE REST OF THIS MESS) What we have today is that in the closer we remove all of the fanotify_response_events and set a bit so no more response events are ever created in prepare_for_access_response(). The bug is that we never wake all of the operators up and tell them to move along. You fix that in fanotify_get_response_from_access(). You also fix other operators which haven't gotten there yet. So I agree that's a good fix. [/additional changelog from eparis] [remove additional changes to minimize patch size] [move initialization so it was inside CONFIG_FANOTIFY_PERMISSION] Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-10-28fanotify: ignore events on directories unless specifically requestedEric Paris1-0/+5
fanotify has a very limited number of events it sends on directories. The usefulness of these events is yet to be seen and still we send them. This is particularly painful for mount marks where one might receive many of these useless events. As such this patch will drop events on IS_DIR() inodes unless they were explictly requested with FAN_ON_DIR. This means that a mark on a directory without FAN_EVENT_ON_CHILD or FAN_ON_DIR is meaningless and will result in no events ever (although it will still be allowed since detecting it is hard) Signed-off-by: Eric Paris <eparis@redhat.com>
2010-10-28fanotify: do not send events for irregular filesEric Paris1-5/+6
fanotify_should_send_event has a test to see if an object is a file or directory and does not send an event otherwise. The problem is that the test is actually checking if the object with a mark is a file or directory, not if the object the event happened on is a file or directory. We should check the latter. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-10-28fanotify: limit number of listeners per userEric Paris1-1/+10
fanotify currently has no limit on the number of listeners a given user can have open. This patch limits the total number of listeners per user to 128. This is the same as the inotify default limit. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-08-22fanotify: drop duplicate pr_debug statementTvrtko Ursulin1-3/+0
This reminded me... you have two pr_debugs in fanotify_should_send_event which output redundant information. Maybe you intended it like that so it is selectable how much log spam you want, or if not you may want to apply this patch. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-08-12Revert "fsnotify: store struct file not struct path"Linus Torvalds1-4/+4
This reverts commit 3bcf3860a4ff9bbc522820b4b765e65e4deceb3e (and the accompanying commit c1e5c954020e "vfs/fsnotify: fsnotify_close can delay the final work in fput" that was a horribly ugly hack to make it work at all). The 'struct file' approach not only causes that disgusting hack, it somehow breaks pulseaudio, probably due to some other subtlety with f_count handling. Fix up various conflicts due to later fsnotify work. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-28fanotify: use both marks when possibleEric Paris1-54/+34
fanotify currently, when given a vfsmount_mark will look up (if it exists) the corresponding inode mark. This patch drops that lookup and uses the mark provided. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: pass both the vfsmount mark and inode markEric Paris1-5/+10
should_send_event() and handle_event() will both need to look up the inode event if they get a vfsmount event. Lets just pass both at the same time since we have them both after walking the lists in lockstep. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: cleanup should_send_eventEric Paris1-15/+8
The change to use srcu and walk the object list rather than the global fsnotify_group list means that should_send_event is no longer needed for a number of groups and can be simplified for others. Do that. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: use the mark in handler functionsEric Paris1-29/+17
fanotify now gets a mark in the should_send_event and handle_event functions. Rather than look up the mark themselves fanotify should just use the mark it was handed. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: send fsnotify_mark to groups in event handling functionsEric Paris1-3/+5
With the change of fsnotify to use srcu walking the marks list instead of walking the global groups list we now know the mark in question. The code can send the mark to the group's handling functions and the groups won't have to find those marks themselves. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: store struct file not struct pathEric Paris1-4/+4
Al explains that calling dentry_open() with a mnt/dentry pair is only garunteed to be safe if they are already used in an open struct file. To make sure this is the case don't store and use a struct path in fsnotify, always use a struct file. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: fsnotify_add_notify_event should return an eventEric Paris1-57/+46
Rather than the horrific void ** argument and such just to pass the fanotify_merge event back to the caller of fsnotify_add_notify_event() have those things return an event if it was different than the event suggusted to be added. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: userspace interface for permission responsesEric Paris1-0/+3
fanotify groups need to respond to events which include permissions types. To do so groups will send a response using write() on the fanotify_fd they have open. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: permissions and blockingEric Paris1-4/+50
This is the backend work needed for fanotify to support the new FS_OPEN_PERM and FS_ACCESS_PERM fsnotify events. This is done using the new fsnotify secondary queue. No userspace interface is provided actually respond to or request these events. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: use merge argument to determine actual event added to queueEric Paris1-5/+16
fanotify needs to know the actual event added to queues so it can be correctly checked for return values from userspace. To do this we need to pass that information from the merger code back to the main even handling routine. Currently that information is unused, but it will be. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: intoduce a notification merge argumentEric Paris1-2/+4
Each group can define their own notification (and secondary_q) merge function. Inotify does tail drop, fanotify does matching and drop which can actually allocate a completely new event. But for fanotify to properly deal with permissions events it needs to know the new event which was ultimately added to the notification queue. This patch just implements a void ** argument which is passed to the merge function. fanotify can use this field to pass the new event back to higher layers. Signed-off-by: Eric Paris <eparis@redhat.com> for fanotify to properly deal with permissions events
2010-07-28fanotify: ignored_mask to ignore eventsEric Paris1-14/+23
When fanotify receives an event it will check event->mask & ~ignored_mask. If no bits are left the event will not be sent. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: remove outgoing function checks in fanotify.hAndreas Gruenbacher1-2/+1
A number of validity checks on outgoing data are done in static inlines but are only used in one place. Instead just do them where they are used for readability. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: should_send_event needs to handle vfsmountsEric Paris1-11/+45
currently should_send_event in fanotify only cares about marks on inodes. This patch extends that interface to indicate that it cares about events that happened on vfsmounts. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: split generic and inode specific mark codeEric Paris1-1/+1
currently all marking is done by functions in inode-mark.c. Some of this is pretty generic and should be instead done in a generic function and we should only put the inode specific code in inode-mark.c Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: Add pids to eventsAndreas Gruenbacher1-2/+3
Pass the process identifiers of the triggering processes to fanotify listeners: this information is useful for event filtering and logging. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: do not clone on merge unless neededEric Paris1-0/+10
Currently if 2 events are going to be merged on the notication queue with different masks the second event will be cloned and will replace the first event. However if this notification queue is the only place referencing the event in question there is no reason not to just update the event in place. We can tell this if the event->refcnt == 1. Since we hold a reference for each queue this event is on we know that when refcnt == 1 this is the only queue. The other concern is that it might be about to be added to a new queue, but this can't be the case since fsnotify holds a reference on the event until it is finished adding it to queues. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: merge notification events with different masksEric Paris1-9/+30
Instead of just merging fanotify events if they are exactly the same, merge notification events with different masks. To do this we have to clone the old event, update the mask in the new event with the new merged mask, and put the new event in place of the old event. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify:drop notification if they exist in the outgoing queueEric Paris1-2/+43
fanotify listeners get an open file descriptor to the object in question so the ordering of operations is not as important as in other notification systems. inotify will drop events if the last event in the event FIFO is the same as the current event. This patch will drop fanotify events if they are the same as another event anywhere in the event FIFO. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fanotify: fscking all notification systemEric Paris1-0/+78
fanotify is a novel file notification system which bases notification on giving userspace both an event type (open, close, read, write) and an open file descriptor to the object in question. This should address a number of races and problems with other notification systems like inotify and dnotify and should allow the future implementation of blocking or access controlled notification. These are useful for on access scanners or hierachical storage management schemes. This patch just implements the basics of the fsnotify functions. Signed-off-by: Eric Paris <eparis@redhat.com>