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2019-05-07Merge branch 'work.dcache' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc dcache updates from Al Viro: "Most of this pile is putting name length into struct name_snapshot and making use of it. The beginning of this series ("ovl_lookup_real_one(): don't bother with strlen()") ought to have been split in two (separate switch of name_snapshot to struct qstr from overlayfs reaping the trivial benefits of that), but I wanted to avoid a rebase - by the time I'd spotted that it was (a) in -next and (b) close to 5.1-final ;-/" * 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: audit_compare_dname_path(): switch to const struct qstr * audit_update_watch(): switch to const struct qstr * inotify_handle_event(): don't bother with strlen() fsnotify: switch send_to_group() and ->handle_event to const struct qstr * fsnotify(): switch to passing const struct qstr * for file_name switch fsnotify_move() to passing const struct qstr * for old_name ovl_lookup_real_one(): don't bother with strlen() sysv: bury the broken "quietly truncate the long filenames" logics nsfs: unobfuscate unexport d_alloc_pseudo()
2019-05-07Merge tag 'pidfd-v5.2-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull pidfd updates from Christian Brauner: "This patchset makes it possible to retrieve pidfds at process creation time by introducing the new flag CLONE_PIDFD to the clone() system call. Linus originally suggested to implement this as a new flag to clone() instead of making it a separate system call. After a thorough review from Oleg CLONE_PIDFD returns pidfds in the parent_tidptr argument. This means we can give back the associated pid and the pidfd at the same time. Access to process metadata information thus becomes rather trivial. As has been agreed, CLONE_PIDFD creates file descriptors based on anonymous inodes similar to the new mount api. They are made unconditional by this patchset as they are now needed by core kernel code (vfs, pidfd) even more than they already were before (timerfd, signalfd, io_uring, epoll etc.). The core patchset is rather small. The bulky looking changelist is caused by David's very simple changes to Kconfig to make anon inodes unconditional. A pidfd comes with additional information in fdinfo if the kernel supports procfs. The fdinfo file contains the pid of the process in the callers pid namespace in the same format as the procfs status file, i.e. "Pid:\t%d". To remove worries about missing metadata access this patchset comes with a sample/test program that illustrates how a combination of CLONE_PIDFD and pidfd_send_signal() can be used to gain race-free access to process metadata through /proc/<pid>. Further work based on this patchset has been done by Joel. His work makes pidfds pollable. It finished too late for this merge window. I would prefer to have it sitting in linux-next for a while and send it for inclusion during the 5.3 merge window" * tag 'pidfd-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: samples: show race-free pidfd metadata access signal: support CLONE_PIDFD with pidfd_send_signal clone: add CLONE_PIDFD Make anon_inodes unconditional
2019-04-28fsnotify: Fix NULL ptr deref in fanotify_get_fsid()Jan Kara
fanotify_get_fsid() is reading mark->connector->fsid under srcu. It can happen that it sees mark not fully initialized or mark that is already detached from the object list. In these cases mark->connector can be NULL leading to NULL ptr dereference. Fix the problem by being careful when reading mark->connector and check it for being NULL. Also use WRITE_ONCE when writing the mark just to prevent compiler from doing something stupid. Reported-by: syzbot+15927486a4f1bfcbaf91@syzkaller.appspotmail.com Fixes: 77115225acc6 ("fanotify: cache fsid in fsnotify_mark_connector") Signed-off-by: Jan Kara <jack@suse.cz>
2019-04-26inotify_handle_event(): don't bother with strlen()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26fsnotify: switch send_to_group() and ->handle_event to const struct qstr *Al Viro
note that conditions surrounding accesses to dname in audit_watch_handle_event() and audit_mark_handle_event() guarantee that dname won't have been NULL. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26fsnotify(): switch to passing const struct qstr * for file_nameAl Viro
Note that in fnsotify_move() and fsnotify_link() we are guaranteed that dentry->d_name won't change during the fsnotify() evaluation (by having the parent directory locked exclusive), so we don't need to fetch dentry->d_name.name in the callers. In fsnotify_dirent() the same stability of dentry->d_name is also true, but it's a bit more convoluted - there is one callchain (devpts_pty_new() -> fsnotify_create() -> fsnotify_dirent()) where the parent is _not_ locked, but on devpts ->d_name of everything is unchanging; it has neither explicit nor implicit renames. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26ovl_lookup_real_one(): don't bother with strlen()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-19Make anon_inodes unconditionalDavid Howells
Make the anon_inodes facility unconditional so that it can be used by core VFS code and pidfd code. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [christian@brauner.io: adapt commit message to mention pidfds] Signed-off-by: Christian Brauner <christian@brauner.io>
2019-03-19fanotify: Allow copying of file handle to userspaceJan Kara
When file handle is embedded inside fanotify_event and usercopy checks are enabled, we get a warning like: Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLAB object 'fanotify_event' (offset 40, size 8)! WARNING: CPU: 1 PID: 7649 at mm/usercopy.c:78 usercopy_warn+0xeb/0x110 mm/usercopy.c:78 Annotate handling in fanotify_event properly to mark copying it to userspace is fine. Reported-by: syzbot+2c49971e251e36216d1f@syzkaller.appspotmail.com Fixes: a8b13aa20afb ("fanotify: enable FAN_REPORT_FID init flag") Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-03-11inotify: Fix fsnotify_mark refcount leak in inotify_update_existing_watch()ZhangXiaoxu
Commit 4d97f7d53da7dc83 ("inotify: Add flag IN_MASK_CREATE for inotify_add_watch()") forgot to call fsnotify_put_mark() with IN_MASK_CREATE after fsnotify_find_mark() Fixes: 4d97f7d53da7dc83 ("inotify: Add flag IN_MASK_CREATE for inotify_add_watch()") Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-21fanotify: Make waits for fanotify events only killableJan Kara
Making waits for response to fanotify permission events interruptible can result in EINTR returns from open(2) or other syscalls when there's e.g. AV software that's monitoring the file. Orion reports that e.g. bash is complaining like: bash: /etc/bash_completion.d/itweb-settings.bash: Interrupted system call So for now convert the wait from interruptible to only killable one. That is mostly invisible to userspace. Sadly this breaks hibernation with fanotify permission events pending again but we have to put more thought into how to fix this without regressing userspace visible behavior. Reported-by: Orion Poplawski <orion@nwra.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-18fanotify: Use interruptible wait when waiting for permission eventsJan Kara
When waiting for response to fanotify permission events, we currently use uninterruptible waits. That makes code simple however it can cause lots of processes to end up in uninterruptible sleep with hard reboot being the only alternative in case fanotify listener process stops responding (e.g. due to a bug in its implementation). Uninterruptible sleep also makes system hibernation fail if the listener gets frozen before the process generating fanotify permission event. Fix these problems by using interruptible sleep for waiting for response to fanotify event. This is slightly tricky though - we have to detect when the event got already reported to userspace as in that case we must not free the event. Instead we push the responsibility for freeing the event to the process that will write response to the event. Reported-by: Orion Poplawski <orion@nwra.com> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-18fanotify: Track permission event stateJan Kara
Track whether permission event got already reported to userspace and whether userspace already answered to the permission event. Protect stores to this field together with updates to ->response field by group->notification_lock. This will allow aborting wait for reply to permission event from userspace. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-18fanotify: Simplify cleaning of access_listJan Kara
Simplify iteration cleaning access_list in fanotify_release(). That will make following changes more obvious. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-18fsnotify: Create function to remove event from notification listJan Kara
Create function to remove event from the notification list. Later it will be used from more places. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-18fanotify: Move locking inside get_one_event()Jan Kara
get_one_event() has a single caller and that just locks notification_lock around the call. Move locking inside get_one_event() as that will make using ->response field for permission event state easier. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-18fanotify: Fold dequeue_event() into process_access_response()Jan Kara
Fold dequeue_event() into process_access_response(). This will make changes to use of ->response field easier. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-14fanotify: Select EXPORTFSJan Kara
Fanotify now uses exportfs_encode_inode_fh() so it needs to select EXPORTFS. Fixes: e9e0c8903009 "fanotify: encode file identifier for FAN_REPORT_FID" Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: report FAN_ONDIR to listener with FAN_REPORT_FIDAmir Goldstein
dirent modification events (create/delete/move) do not carry the child entry name/inode information. Instead, we report FAN_ONDIR for mkdir/rmdir so user can differentiate them from creat/unlink. This is consistent with inotify reporting IN_ISDIR with dirent events and is useful for implementing recursive directory tree watcher. We avoid merging dirent events referring to subdirs with dirent events referring to non subdirs, otherwise, user won't be able to tell from a mask FAN_CREATE|FAN_DELETE|FAN_ONDIR if it describes mkdir+unlink pair or rmdir+create pair of events. For backward compatibility and consistency, do not report FAN_ONDIR to user in legacy fanotify mode (reporting fd) and report FAN_ONDIR to user in FAN_REPORT_FID mode for all event types. Cc: <linux-api@vger.kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: add support for create/attrib/move/delete eventsAmir Goldstein
Add support for events with data type FSNOTIFY_EVENT_INODE (e.g. create/attrib/move/delete) for inode and filesystem mark types. The "inode" events do not carry enough information (i.e. path) to report event->fd, so we do not allow setting a mask for those events unless group supports reporting fid. The "inode" events are not supported on a mount mark, because they do not carry enough information (i.e. path) to be filtered by mount point. The "dirent" events (create/move/delete) report the fid of the parent directory where events took place without specifying the filename of the child. In the future, fanotify may get support for reporting filename information for those events. Cc: <linux-api@vger.kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: support events with data type FSNOTIFY_EVENT_INODEAmir Goldstein
When event data type is FSNOTIFY_EVENT_INODE, we don't have a refernece to the mount, so we will not be able to open a file descriptor when user reads the event. However, if the listener has enabled reporting file identifier with the FAN_REPORT_FID init flag, we allow reporting those events and we use an identifier inode to encode fid. The inode to use as identifier when reporting fid depends on the event. For dirent modification events, we report the modified directory inode and we report the "victim" inode otherwise. For example: FS_ATTRIB reports the child inode even if reported on a watched parent. FS_CREATE reports the modified dir inode and not the created inode. [JK: Fixup condition in fanotify_group_event_mask()] Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: check FS_ISDIR flag instead of d_is_dir()Amir Goldstein
All fsnotify hooks set the FS_ISDIR flag for events that happen on directory victim inodes except for fsnotify_perm(). Add the missing FS_ISDIR flag in fsnotify_perm() hook and let fanotify_group_event_mask() check the FS_ISDIR flag instead of checking if path argument is a directory. This is needed for fanotify support for event types that do not carry path information. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fsnotify: report FS_ISDIR flag with MOVE_SELF and DELETE_SELF eventsAmir Goldstein
We need to report FS_ISDIR flag with MOVE_SELF and DELETE_SELF events for fanotify, because fanotify API requires the user to explicitly request events on directories by FAN_ONDIR flag. inotify never reported IN_ISDIR with those events. It looks like an oversight, but to avoid the risk of breaking existing inotify programs, mask the FS_ISDIR flag out when reprting those events to inotify backend. We also add the FS_ISDIR flag with FS_ATTRIB event in the case of rename over an empty target directory. inotify did not report IN_ISDIR in this case, but it normally does report IN_ISDIR along with IN_ATTRIB event, so in this case, we do not mask out the FS_ISDIR flag. [JK: Simplify the checks in fsnotify_move()] Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: use vfs_get_fsid() helper instead of vfs_statfs()Amir Goldstein
This is a cleanup that doesn't change any logic. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: cache fsid in fsnotify_mark_connectorAmir Goldstein
For FAN_REPORT_FID, we need to encode fid with fsid of the filesystem on every event. To avoid having to call vfs_statfs() on every event to get fsid, we store the fsid in fsnotify_mark_connector on the first time we add a mark and on handle event we use the cached fsid. Subsequent calls to add mark on the same object are expected to pass the same fsid, so the call will fail on cached fsid mismatch. If an event is reported on several mark types (inode, mount, filesystem), all connectors should already have the same fsid, so we use the cached fsid from the first connector. [JK: Simplify code flow around fanotify_get_fid() make fsid argument of fsnotify_add_mark_locked() unconditional] Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: enable FAN_REPORT_FID init flagAmir Goldstein
When setting up an fanotify listener, user may request to get fid information in event instead of an open file descriptor. The fid obtained with event on a watched object contains the file handle returned by name_to_handle_at(2) and fsid returned by statfs(2). Restrict FAN_REPORT_FID to class FAN_CLASS_NOTIF, because we have have no good reason to support reporting fid on permission events. When setting a mark, we need to make sure that the filesystem supports encoding file handles with name_to_handle_at(2) and that statfs(2) encodes a non-zero fsid. Cc: <linux-api@vger.kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: copy event fid info to userAmir Goldstein
If group requested FAN_REPORT_FID and event has file identifier, copy that information to user reading the event after event metadata. fid information is formatted as struct fanotify_event_info_fid that includes a generic header struct fanotify_event_info_header, so that other info types could be defined in the future using the same header. metadata->event_len includes the length of the fid information. The fid information includes the filesystem's fsid (see statfs(2)) followed by an NFS file handle of the file that could be passed as an argument to open_by_handle_at(2). Cc: <linux-api@vger.kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: encode file identifier for FAN_REPORT_FIDAmir Goldstein
When user requests the flag FAN_REPORT_FID in fanotify_init(), a unique file identifier of the event target object will be reported with the event. The file identifier includes the filesystem's fsid (i.e. from statfs(2)) and an NFS file handle of the file (i.e. from name_to_handle_at(2)). The file identifier makes holding the path reference and passing a file descriptor to user redundant, so those are disabled in a group with FAN_REPORT_FID. Encode fid and store it in event for a group with FAN_REPORT_FID. Up to 12 bytes of file handle on 32bit arch (16 bytes on 64bit arch) are stored inline in fanotify_event struct. Larger file handles are stored in an external allocated buffer. On failure to encode fid, we print a warning and queue the event without the fid information. [JK: Fold part of later patched into this one to use exportfs_encode_inode_fh() right away] Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-07fanotify: open code fill_event_metadata()Amir Goldstein
The helper is quite trivial and open coding it will make it easier to implement copying event fid info to user. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-06fanotify: rename struct fanotify_{,perm_}event_infoAmir Goldstein
struct fanotify_event_info "inherits" from struct fsnotify_event and therefore a more appropriate (and short) name for it is fanotify_event. Same for struct fanotify_perm_event_info, which now "inherits" from struct fanotify_event. We plan to reuse the name struct fanotify_event_info for user visible event info record format. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-06fsnotify: move mask out of struct fsnotify_eventAmir Goldstein
Common fsnotify_event helpers have no need for the mask field. It is only used by backend code, so move the field out of the abstract fsnotify_event struct and into the concrete backend event structs. This change packs struct inotify_event_info better on 64bit machine and will allow us to cram some more fields into struct fanotify_event_info. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-02-06fsnotify: send all event types to super block marksAmir Goldstein
So far, existence of super block marks was checked only on events with data type FSNOTIFY_EVENT_PATH. Use the super block of the "to_tell" inode to report the events of all event types to super block marks. This change has no effect on current backends. Soon, this will allow fanotify backend to receive all event types on a super block mark. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-01-02inotify: Fix fd refcount leak in inotify_add_watch().Tetsuo Handa
Commit 4d97f7d53da7dc83 ("inotify: Add flag IN_MASK_CREATE for inotify_add_watch()") forgot to call fdput() before bailing out. Fixes: 4d97f7d53da7dc83 ("inotify: Add flag IN_MASK_CREATE for inotify_add_watch()") CC: stable@vger.kernel.org Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-12-11fanotify: Use inode_is_open_for_writeNikolay Borisov
Use the aptly named function rather than opencoding i_writecount check. No functional changes. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-12-05fanotify: Make sure to check event_len when copyingKees Cook
As a precaution, make sure we check event_len when copying to userspace. Based on old feedback: https://lkml.kernel.org/r/542D9FE5.3010009@gmx.de Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-15fsnotify/fdinfo: include fdinfo.h for inotify_show_fdinfo()Eric Biggers
inotify_show_fdinfo() is defined in fs/notify/fdinfo.c and declared in fs/notify/fdinfo.h, but the declaration isn't included at the point of the definition. Include the header to enforce that the definition matches the declaration. This addresses a gcc warning when -Wmissing-prototypes is enabled. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-13fanotify: introduce new event mask FAN_OPEN_EXEC_PERMMatthew Bobrowski
A new event mask FAN_OPEN_EXEC_PERM has been defined. This allows users to receive events and grant access to files that are intending to be opened for execution. Events of FAN_OPEN_EXEC_PERM type will be generated when a file has been opened by using either execve(), execveat() or uselib() system calls. This acts in the same manner as previous permission event mask, meaning that an access response is required from the user application in order to permit any further operations on the file. Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-13fanotify: introduce new event mask FAN_OPEN_EXECMatthew Bobrowski
A new event mask FAN_OPEN_EXEC has been defined so that users have the ability to receive events specifically when a file has been opened with the intent to be executed. Events of FAN_OPEN_EXEC type will be generated when a file has been opened using either execve(), execveat() or uselib() system calls. The feature is implemented within fsnotify_open() by generating the FAN_OPEN_EXEC event type if __FMODE_EXEC is set within file->f_flags. Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-13fanotify: return only user requested event types in event maskMatthew Bobrowski
Modify fanotify_should_send_event() so that it now returns a mask for an event that contains ONLY flags for the event types that have been specifically requested by the user. Flags that may have been included within the event mask, but have not been explicitly requested by the user will not be present in the returned value. As an example, given the situation where a user requests events of type FAN_OPEN. Traditionally, the event mask returned within an event that occurred on a filesystem object that has been marked for monitoring and is opened, will only ever have the FAN_OPEN bit set. With the introduction of the new flags like FAN_OPEN_EXEC, and perhaps any other future event flags, there is a possibility of the returned event mask containing more than a single bit set, despite having only requested the single event type. Prior to these modifications performed to fanotify_should_send_event(), a user would have received a bundled event mask containing flags FAN_OPEN and FAN_OPEN_EXEC in the instance that a file was opened for execution via execve(), for example. This means that a user would receive event types in the returned event mask that have not been requested. This runs the possibility of breaking existing systems and causing other unforeseen issues. To mitigate this possibility, fanotify_should_send_event() has been modified to return the event mask containing ONLY event types explicitly requested by the user. This means that we will NOT report events that the user did no set a mask for, and we will NOT report events that the user has set an ignore mask for. The function name fanotify_should_send_event() has also been updated so that it's more relevant to what it has been designed to do. Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-08fanotify: fix handling of events on child sub-directoryAmir Goldstein
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>
2018-10-25fsnotify: Fix busy inodes during unmountJan Kara
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: 6b3f05d24d35 ("fsnotify: Detach mark from object list when last reference is dropped") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz>
2018-10-08fanotify: support reporting thread id instead of process idAmir Goldstein
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>
2018-10-04fanotify: add BUILD_BUG_ON() to count the bits of fanotify constantsAmir Goldstein
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>
2018-10-04fsnotify: convert runtime BUG_ON() to BUILD_BUG_ON()Amir Goldstein
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>
2018-10-04fanotify: deprecate uapi FAN_ALL_* constantsAmir Goldstein
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>
2018-10-04fanotify: simplify handling of FAN_ONDIRAmir Goldstein
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>
2018-10-04fsnotify: generalize handling of extra event flagsAmir Goldstein
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>
2018-09-27fanotify: store fanotify_init() flags in group's fanotify_dataAmir Goldstein
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>
2018-09-03fanotify: add API to attach/detach super block markAmir Goldstein
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>
2018-09-03fsnotify: send path type events to group with super block marksAmir Goldstein
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>