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2019-08-19notify: export symbols for use by the knfsd file cacheTrond Myklebust1-0/+2
The knfsd file cache will need to detect when files are unlinked, so that it can close the associated cached files. Export a minimal set of notifier functions to allow it to do so. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-07-10Merge tag 'fsnotify_for_v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fsLinus Torvalds1-4/+0
Pull fsnotify updates from Jan Kara: "This contains cleanups of the fsnotify name removal hook and also a patch to disable fanotify permission events for 'proc' filesystem" * tag 'fsnotify_for_v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: get rid of fsnotify_nameremove() fsnotify: move fsnotify_nameremove() hook out of d_delete() configfs: call fsnotify_rmdir() hook debugfs: call fsnotify_{unlink,rmdir}() hooks debugfs: simplify __debugfs_remove_file() devpts: call fsnotify_unlink() hook tracefs: call fsnotify_{unlink,rmdir}() hooks rpc_pipefs: call fsnotify_{unlink,rmdir}() hooks btrfs: call fsnotify_rmdir() hook fsnotify: add empty fsnotify_{unlink,rmdir}() hooks fanotify: Disallow permission events for proc filesystem
2019-06-20fsnotify: get rid of fsnotify_nameremove()Amir Goldstein1-4/+0
For all callers of fsnotify_{unlink,rmdir}(), we made sure that d_parent and d_name are stable. Therefore, fsnotify_{unlink,rmdir}() do not need the safety measures in fsnotify_nameremove() to stabilize parent and name. We can now simplify those hooks and get rid of fsnotify_nameremove(). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-06-19fanotify: update connector fsid cache on add markAmir Goldstein1-1/+3
When implementing connector fsid cache, we only initialized the cache when the first mark added to object was added by FAN_REPORT_FID group. We forgot to update conn->fsid when the second mark is added by FAN_REPORT_FID group to an already attached connector without fsid cache. Reported-and-tested-by: syzbot+c277e8e2f46414645508@syzkaller.appspotmail.com Fixes: 77115225acc6 ("fanotify: cache fsid in fsnotify_mark_connector") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-05-13Merge tag 'fsnotify_for_v5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jack/linux-fsLinus Torvalds1-0/+4
Pull fsnotify fixes from Jan Kara: "Two fsnotify fixes" * tag 'fsnotify_for_v5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: fix unlink performance regression fsnotify: Clarify connector assignment in fsnotify_add_mark_list()
2019-05-09fsnotify: fix unlink performance regressionAmir Goldstein1-0/+4
__fsnotify_parent() has an optimization in place to avoid unneeded take_dentry_name_snapshot(). When fsnotify_nameremove() was changed not to call __fsnotify_parent(), we left out the optimization. Kernel test robot reported a 5% performance regression in concurrent unlink() workload. Reported-by: kernel test robot <rong.a.chen@intel.com> Link: https://lore.kernel.org/lkml/20190505062153.GG29809@shao2-debian/ Link: https://lore.kernel.org/linux-fsdevel/20190104090357.GD22409@quack2.suse.cz/ Fixes: 5f02a8776384 ("fsnotify: annotate directory entry modification events") CC: stable@vger.kernel.org Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-04-26fsnotify: switch send_to_group() and ->handle_event to const struct qstr *Al Viro1-1/+1
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 Viro1-2/+2
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>
2019-02-18fsnotify: Create function to remove event from notification listJan Kara1-0/+3
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>
2019-02-07fanotify: cache fsid in fsnotify_mark_connectorAmir Goldstein1-5/+13
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>
2019-02-06fsnotify: move mask out of struct fsnotify_eventAmir Goldstein1-4/+6
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: remove dirent events from FS_EVENTS_POSS_ON_CHILD maskAmir Goldstein1-15/+21
"dirent" events are referring to events that modify directory entries, such as create,delete,rename. Those events are always be reported on a watched directory, regardless if FS_EVENT_ON_CHILD is set on the watch mask. ALL_FSNOTIFY_DIRENT_EVENTS defines all the dirent event types and those event types are removed from FS_EVENTS_POSS_ON_CHILD. That means for a directory with an inotify watch and only dirent events in the mask (i.e. create,delete,move), all children dentries will no longer have the DCACHE_FSNOTIFY_PARENT_WATCHED flag set. This will allow all events that happen on children to be optimized away in __fsnotify_parent() without the need to dereference child->d_parent->d_inode->i_fsnotify_mask. Since the dirent events are never repoted via __fsnotify_parent(), this results in no change of logic, but only an optimization. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-11-13fanotify: introduce new event mask FAN_OPEN_EXEC_PERMMatthew Bobrowski1-3/+5
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 Bobrowski1-2/+5
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>
2018-10-04fsnotify: generalize handling of extra event flagsAmir Goldstein1-2/+7
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 Goldstein1-2/+2
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>
2018-09-03fsnotify: add super block object typeAmir Goldstein1-3/+14
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>
2018-08-17Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-4/+8
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() ...
2018-08-17fs: fsnotify: account fsnotify metadata to kmemcgShakeel Butt1-4/+8
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>
2018-06-27fsnotify: add helper to get mask from connectorAmir Goldstein1-0/+2
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>
2018-06-27fsnotify: let connector point to an abstract objectAmir Goldstein1-5/+10
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>
2018-06-27fsnotify: pass connp and object type to fsnotify_add_mark()Amir Goldstein1-6/+14
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>
2018-06-27fsnotify: use typedef fsnotify_connp_t for brevityAmir Goldstein1-3/+4
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>
2018-05-18fsnotify: add fsnotify_add_inode_mark() wrappersAmir Goldstein1-1/+15
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>
2018-05-18fsnotify: generalize iteration of marks by object typeAmir Goldstein1-3/+25
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>
2018-05-18fsnotify: remove redundant arguments to handle_event()Amir Goldstein1-2/+18
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>
2018-05-18fsnotify: use type id to identify connector object typeAmir Goldstein1-7/+14
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>
2018-04-25Merge tag 'for_v4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fsLinus Torvalds1-3/+1
Pull fsnotify fix from Jan Kara: "A fix of a fsnotify race causing panics / softlockups" * tag 'for_v4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: Fix fsnotify_mark_connector race
2018-04-19fsnotify: Fix fsnotify_mark_connector raceRobert Kolchmeyer1-3/+1
fsnotify() acquires a reference to a fsnotify_mark_connector through the SRCU-protected pointer to_tell->i_fsnotify_marks. However, it appears that no precautions are taken in fsnotify_put_mark() to ensure that fsnotify() drops its reference to this fsnotify_mark_connector before assigning a value to its 'destroy_next' field. This can result in fsnotify_put_mark() assigning a value to a connector's 'destroy_next' field right before fsnotify() tries to traverse the linked list referenced by the connector's 'list' field. Since these two fields are members of the same union, this behavior results in a kernel panic. This issue is resolved by moving the connector's 'destroy_next' field into the object pointer union. This should work since the object pointer access is protected by both a spinlock and the value of the 'flags' field, and the 'flags' field is cleared while holding the spinlock in fsnotify_put_mark() before 'destroy_next' is updated. It shouldn't be possible for another thread to accidentally read from the object pointer after the 'destroy_next' field is updated. The offending behavior here is extremely unlikely; since fsnotify_put_mark() removes references to a connector (specifically, it ensures that the connector is unreachable from the inode it was formerly attached to) before updating its 'destroy_next' field, a sizeable chunk of code in fsnotify_put_mark() has to execute in the short window between when fsnotify() acquires the connector reference and saves the value of its 'list' field. On the HEAD kernel, I've only been able to reproduce this by inserting a udelay(1) in fsnotify(). However, I've been able to reproduce this issue without inserting a udelay(1) anywhere on older unmodified release kernels, so I believe it's worth fixing at HEAD. References: https://bugzilla.kernel.org/show_bug.cgi?id=199437 Fixes: 08991e83b7286635167bab40927665a90fb00d81 CC: stable@vger.kernel.org Signed-off-by: Robert Kolchmeyer <rkolchmeyer@google.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-04-13fsnotify: fix typo in a comment about mark->g_listAmir Goldstein1-1/+1
Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-02-27fsnotify: Let userspace know about lost events due to ENOMEMJan Kara1-0/+6
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>
2017-11-14Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fsLinus Torvalds1-0/+1
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
2017-11-14Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fsLinus Torvalds1-4/+3
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()
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
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>
2017-10-31fsnotify: convert fsnotify_mark.refcnt from atomic_t to refcount_tElena Reshetova1-1/+1
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>
2017-10-31fanotify: clean up CONFIG_FANOTIFY_ACCESS_PERMISSIONS ifdefsMiklos Szeredi1-2/+0
The only negative from this patch should be an addition of 32bytes to 'struct fsnotify_group' if CONFIG_FANOTIFY_ACCESS_PERMISSIONS is not defined. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-10-31fsnotify: convert fsnotify_group.refcnt from atomic_t to refcount_tElena Reshetova1-1/+2
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_group.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>
2017-10-10audit: Record fanotify access control decisionsSteve Grubb1-0/+1
The fanotify interface allows user space daemons to make access control decisions. Under common criteria requirements, we need to optionally record decisions based on policy. This patch adds a bit mask, FAN_AUDIT, that a user space daemon can 'or' into the response decision which will tell the kernel that it made a decision and record it. It would be used something like this in user space code: response.response = FAN_DENY | FAN_AUDIT; write(fd, &response, sizeof(struct fanotify_response)); When the syscall ends, the audit system will record the decision as a AUDIT_FANOTIFY auxiliary record to denote that the reason this event occurred is the result of an access control decision from fanotify rather than DAC or MAC policy. A sample event looks like this: type=PATH msg=audit(1504310584.332:290): item=0 name="./evil-ls" inode=1319561 dev=fc:03 mode=0100755 ouid=1000 ogid=1000 rdev=00:00 obj=unconfined_u:object_r:user_home_t:s0 nametype=NORMAL type=CWD msg=audit(1504310584.332:290): cwd="/home/sgrubb" type=SYSCALL msg=audit(1504310584.332:290): arch=c000003e syscall=2 success=no exit=-1 a0=32cb3fca90 a1=0 a2=43 a3=8 items=1 ppid=901 pid=959 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000 fsuid=1000 egid=1000 sgid=1000 fsgid=1000 tty=pts1 ses=3 comm="bash" exe="/usr/bin/bash" subj=unconfined_u:unconfined_r:unconfined_t: s0-s0:c0.c1023 key=(null) type=FANOTIFY msg=audit(1504310584.332:290): resp=2 Prior to using the audit flag, the developer needs to call fanotify_init or'ing in FAN_ENABLE_AUDIT to ensure that the kernel supports auditing. The calling process must also have the CAP_AUDIT_WRITE capability. Signed-off-by: sgrubb <sgrubb@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Move ->free_mark callback to fsnotify_opsJan Kara1-3/+3
Pointer to ->free_mark callback unnecessarily occupies one long in each fsnotify_mark although they are the same for all marks from one notification group. Move the callback pointer to fsnotify_ops. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Add group pointer in fsnotify_init_mark()Jan Kara1-5/+7
Currently we initialize mark->group only in fsnotify_add_mark_lock(). However we will need to access fsnotify_ops of corresponding group from fsnotify_put_mark() so we need mark->group initialized earlier. Do that in fsnotify_init_mark() which has a consequence that once fsnotify_init_mark() is called on a mark, the mark has to be destroyed by fsnotify_put_mark(). Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark()Jan Kara1-4/+4
These are very thin wrappers, just remove them. Drop fs/notify/vfsmount_mark.c as it is empty now. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_detach_group_marks()Jan Kara1-0/+2
The function is already mostly contained in what fsnotify_clear_marks_by_group() does. Just update that function to not select marks when all of them should be destroyed and remove fsnotify_detach_group_marks(). Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Rename fsnotify_clear_marks_by_group_flags()Jan Kara1-3/+3
The _flags() suffix in the function name was more confusing than explaining so just remove it. Also rename the argument from 'flags' to 'type' to better explain what the function expects. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Suggested-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Inline fsnotify_clear_{inode|vfsmount}_mark_group()Jan Kara1-4/+10
Inline these helpers as they are very thin. We still keep them as we don't want to expose details about how list type is determined. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_recalc_{inode|vfsmount}_mask()Jan Kara1-4/+0
These helpers are just very thin wrappers now. Remove them. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Remove fsnotify_set_mark_{,ignored_}mask_locked()Jan Kara1-4/+0
These helpers are now only a simple assignment and just obfuscate what is going on. Remove them. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Pass fsnotify_iter_info into handle_event handlerJan Kara1-1/+2
Pass fsnotify_iter_info into ->handle_event() handler so that it can release and reacquire SRCU lock via fsnotify_prepare_user_wait() and fsnotify_finish_user_wait() functions. These functions also make sure current marks are appropriately pinned so that iteration protected by srcu in fsnotify() stays safe. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Provide framework for dropping SRCU lock in ->handle_eventJan Kara1-0/+5
fanotify wants to drop fsnotify_mark_srcu lock when waiting for response from userspace so that the whole notification subsystem is not blocked during that time. This patch provides a framework for safely getting mark reference for a mark found in the object list which pins the mark in that list. We can then drop fsnotify_mark_srcu, wait for userspace response and then safely continue iteration of the object list once we reaquire fsnotify_mark_srcu. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Detach mark from object list when last reference is droppedJan Kara1-2/+2
Instead of removing mark from object list from fsnotify_detach_mark(), remove the mark when last reference to the mark is dropped. This will allow fanotify to wait for userspace response to event without having to hold onto fsnotify_mark_srcu. To avoid pinning inodes by elevated refcount (and thus e.g. delaying file deletion) while someone holds mark reference, we detach connector from the object also from fsnotify_destroy_marks() and not only after removing last mark from the list as it was now. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10fsnotify: Free fsnotify_mark_connector when there is no mark attachedJan Kara1-4/+7
Currently we free fsnotify_mark_connector structure only when inode / vfsmount is getting freed. This can however impose noticeable memory overhead when marks get attached to inodes only temporarily. So free the connector structure once the last mark is detached from the object. Since notification infrastructure can be working with the connector under the protection of fsnotify_mark_srcu, we have to be careful and free the fsnotify_mark_connector only after SRCU period passes. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>