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2015-01-09sched, fanotify: Deal with nested sleepsPeter Zijlstra
As per e23738a7300a ("sched, inotify: Deal with nested sleeps"). fanotify_read is a wait loop with sleeps in. Wait loops rely on task_struct::state and sleeps do too, since that's the only means of actually sleeping. Therefore the nested sleeps destroy the wait loop state and the wait loop breaks the sleep functions that assume TASK_RUNNING (mutex_lock). Fix this by using the new woken_wake_function and wait_woken() stuff, which registers wakeups in wait and thereby allows shrinking the task_state::state changes to the actual sleep part. Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Takashi Iwai <tiwai@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Paris <eparis@redhat.com> Link: http://lkml.kernel.org/r/20141216152838.GZ3337@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-13fsnotify: remove destroy_list from fsnotify_markJan Kara
destroy_list is used to track marks which still need waiting for srcu period end before they can be freed. However by the time mark is added to destroy_list it isn't in group's list of marks anymore and thus we can reuse fsnotify_mark->g_list for queueing into destroy_list. This saves two pointers for each fsnotify_mark. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13fsnotify: unify inode and mount marks handlingJan Kara
There's a lot of common code in inode and mount marks handling. Factor it out to a common helper function. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS changes from Al Viro: "First pile out of several (there _definitely_ will be more). Stuff in this one: - unification of d_splice_alias()/d_materialize_unique() - iov_iter rewrite - killing a bunch of ->f_path.dentry users (and f_dentry macro). Getting that completed will make life much simpler for unionmount/overlayfs, since then we'll be able to limit the places sensitive to file _dentry_ to reasonably few. Which allows to have file_inode(file) pointing to inode in a covered layer, with dentry pointing to (negative) dentry in union one. Still not complete, but much closer now. - crapectomy in lustre (dead code removal, mostly) - "let's make seq_printf return nothing" preparations - assorted cleanups and fixes There _definitely_ will be more piles" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) copy_from_iter_nocache() new helper: iov_iter_kvec() csum_and_copy_..._iter() iov_iter.c: handle ITER_KVEC directly iov_iter.c: convert copy_to_iter() to iterate_and_advance iov_iter.c: convert copy_from_iter() to iterate_and_advance iov_iter.c: get rid of bvec_copy_page_{to,from}_iter() iov_iter.c: convert iov_iter_zero() to iterate_and_advance iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds iov_iter.c: convert iov_iter_get_pages() to iterate_all_kinds iov_iter.c: convert iov_iter_npages() to iterate_all_kinds iov_iter.c: iterate_and_advance iov_iter.c: macros for iterating over iov_iter kill f_dentry macro dcache: fix kmemcheck warning in switch_names new helper: audit_file() nfsd_vfs_write(): use file_inode() ncpfs: use file_inode() kill f_dentry uses lockd: get rid of ->f_path.dentry->d_sb ...
2014-12-09Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle are: - 'Nested Sleep Debugging', activated when CONFIG_DEBUG_ATOMIC_SLEEP=y. This instruments might_sleep() checks to catch places that nest blocking primitives - such as mutex usage in a wait loop. Such bugs can result in hard to debug races/hangs. Another category of invalid nesting that this facility will detect is the calling of blocking functions from within schedule() -> sched_submit_work() -> blk_schedule_flush_plug(). There's some potential for false positives (if secondary blocking primitives themselves are not ready yet for this facility), but the kernel will warn once about such bugs per bootup, so the warning isn't much of a nuisance. This feature comes with a number of fixes, for problems uncovered with it, so no messages are expected normally. - Another round of sched/numa optimizations and refinements, for CONFIG_NUMA_BALANCING=y. - Another round of sched/dl fixes and refinements. Plus various smaller fixes and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) sched: Add missing rcu protection to wake_up_all_idle_cpus sched/deadline: Introduce start_hrtick_dl() for !CONFIG_SCHED_HRTICK sched/numa: Init numa balancing fields of init_task sched/deadline: Remove unnecessary definitions in cpudeadline.h sched/cpupri: Remove unnecessary definitions in cpupri.h sched/deadline: Fix rq->dl.pushable_tasks bug in push_dl_task() sched/fair: Fix stale overloaded status in the busiest group finding logic sched: Move p->nr_cpus_allowed check to select_task_rq() sched/completion: Document when to use wait_for_completion_io_*() sched: Update comments about CLONE_NEWUTS and CLONE_NEWIPC sched/fair: Kill task_struct::numa_entry and numa_group::task_list sched: Refactor task_struct to use numa_faults instead of numa_* pointers sched/deadline: Don't check CONFIG_SMP in switched_from_dl() sched/deadline: Reschedule from switched_from_dl() after a successful pull sched/deadline: Push task away if the deadline is equal to curr during wakeup sched/deadline: Add deadline rq status print sched/deadline: Fix artificial overrun introduced by yield_task_dl() sched/rt: Clean up check_preempt_equal_prio() sched/core: Use dl_bw_of() under rcu_read_lock_sched() sched: Check if we got a shallowest_idle_cpu before searching for least_loaded_cpu ...
2014-12-08Merge branch 'iov_iter' into for-nextAl Viro
2014-11-19Merge tag 'trace-seq-file-cleanup' of ↵Al Viro
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into for-next Pull the beginning of seq_file cleanup from Steven: "I'm looking to clean up the seq_file code and to eventually merge the trace_seq code with seq_file as well, since they basically do the same thing. Part of this process is to remove the return code of seq_printf() and friends as they are rather inconsistent. It is better to use the new function seq_has_overflowed() if you want to stop processing when the buffer is full. Note, if the buffer is full, the seq_file code will throw away the contents, allocate a bigger buffer, and then call your code again to fill in the data. The only thing that breaking out of the function early does is to save a little time which is probably never noticed. I started with patches from Joe Perches and modified them as well. There's many more places that need to be updated before we can convert seq_printf() and friends to return void. But this patch set introduces the seq_has_overflowed() and does some initial updates."
2014-11-16Merge branch 'sched/urgent' into sched/core, to pick up fixes before ↵Ingo Molnar
applying more changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-13fanotify: fix notification of groups with inode & mount marksJan Kara
fsnotify() needs to merge inode and mount marks lists when notifying groups about events so that ignore masks from inode marks are reflected in mount mark notifications and groups are notified in proper order (according to priorities). Currently the sorting of the lists done by fsnotify_add_inode_mark() / fsnotify_add_vfsmount_mark() and fsnotify() differed which resulted ignore masks not being used in some cases. Fix the problem by always using the same comparison function when sorting / merging the mark lists. Thanks to Heinrich Schuchardt for improvements of my patch. Link: https://bugzilla.kernel.org/show_bug.cgi?id=87721 Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-05fs: Convert show_fdinfo functions to voidJoe Perches
seq_printf functions shouldn't really check the return value. Checking seq_has_overflowed() occasionally is used instead. Update vfs documentation. Link: http://lkml.kernel.org/p/e37e6e7b76acbdcc3bb4ab2a57c8f8ca1ae11b9a.1412031505.git.joe@perches.com Cc: David S. Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Joe Perches <joe@perches.com> [ did a few clean ups ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-03move d_rcu from overlapping d_child to overlapping d_aliasAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-29fsnotify: next_i is freed during fsnotify_unmount_inodes.Jerry Hoemann
During file system stress testing on 3.10 and 3.12 based kernels, the umount command occasionally hung in fsnotify_unmount_inodes in the section of code: spin_lock(&inode->i_lock); if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) { spin_unlock(&inode->i_lock); continue; } As this section of code holds the global inode_sb_list_lock, eventually the system hangs trying to acquire the lock. Multiple crash dumps showed: The inode->i_state == 0x60 and i_count == 0 and i_sb_list would point back at itself. As this is not the value of list upon entry to the function, the kernel never exits the loop. To help narrow down problem, the call to list_del_init in inode_sb_list_del was changed to list_del. This poisons the pointers in the i_sb_list and causes a kernel to panic if it transverse a freed inode. Subsequent stress testing paniced in fsnotify_unmount_inodes at the bottom of the list_for_each_entry_safe loop showing next_i had become free. We believe the root cause of the problem is that next_i is being freed during the window of time that the list_for_each_entry_safe loop temporarily releases inode_sb_list_lock to call fsnotify and fsnotify_inode_delete. The code in fsnotify_unmount_inodes attempts to prevent the freeing of inode and next_i by calling __iget. However, the code doesn't do the __iget call on next_i if i_count == 0 or if i_state & (I_FREEING | I_WILL_FREE) The patch addresses this issue by advancing next_i in the above two cases until we either find a next_i which we can __iget or we reach the end of the list. This makes the handling of next_i more closely match the handling of the variable "inode." The time to reproduce the hang is highly variable (from hours to days.) We ran the stress test on a 3.10 kernel with the proposed patch for a week without failure. During list_for_each_entry_safe, next_i is becoming free causing the loop to never terminate. Advance next_i in those cases where __iget is not done. Signed-off-by: Jerry Hoemann <jerry.hoemann@hp.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ken Helias <kenhelias@firemail.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-28sched, inotify: Deal with nested sleepsPeter Zijlstra
inotify_read is a wait loop with sleeps in. Wait loops rely on task_struct::state and sleeps do too, since that's the only means of actually sleeping. Therefore the nested sleeps destroy the wait loop state and the wait loop breaks the sleep functions that assume TASK_RUNNING (mutex_lock). Fix this by using the new woken_wake_function and wait_woken() stuff, which registers wakeups in wait and thereby allows shrinking the task_state::state changes to the actual sleep part. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: tglx@linutronix.de Cc: ilya.dryomov@inktank.com Cc: umgwanakikbuti@gmail.com Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140924082242.254858080@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-11Merge tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linuxLinus Torvalds
Pull file locking related changes from Jeff Layton: "This release is a little more busy for file locking changes than the last: - a set of patches from Kinglong Mee to fix the lockowner handling in knfsd - a pile of cleanups to the internal file lease API. This should get us a bit closer to allowing for setlease methods that can block. There are some dependencies between mine and Bruce's trees this cycle, and I based my tree on top of the requisite patches in Bruce's tree" * tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linux: (26 commits) locks: fix fcntl_setlease/getlease return when !CONFIG_FILE_LOCKING locks: flock_make_lock should return a struct file_lock (or PTR_ERR) locks: set fl_owner for leases to filp instead of current->files locks: give lm_break a return value locks: __break_lease cleanup in preparation of allowing direct removal of leases locks: remove i_have_this_lease check from __break_lease locks: move freeing of leases outside of i_lock locks: move i_lock acquisition into generic_*_lease handlers locks: define a lm_setup handler for leases locks: plumb a "priv" pointer into the setlease routines nfsd: don't keep a pointer to the lease in nfs4_file locks: clean up vfs_setlease kerneldoc comments locks: generic_delete_lease doesn't need a file_lock at all nfsd: fix potential lease memory leak in nfs4_setlease locks: close potential race in lease_get_mtime security: make security_file_set_fowner, f_setown and __f_setown void return locks: consolidate "nolease" routines locks: remove lock_may_read and lock_may_write lockd: rip out deferred lock handling from testlock codepath NFSD: Get reference of lockowner when coping file_lock ...
2014-10-09fanotify: enable close-on-exec on events' fd when requested in fanotify_init()Yann Droneaud
According to commit 80af258867648 ("fanotify: groups can specify their f_flags for new fd"), file descriptors created as part of file access notification events inherit flags from the event_f_flags argument passed to syscall fanotify_init(2)[1]. Unfortunately O_CLOEXEC is currently silently ignored. Indeed, event_f_flags are only given to dentry_open(), which only seems to care about O_ACCMODE and O_PATH in do_dentry_open(), O_DIRECT in open_check_o_direct() and O_LARGEFILE in generic_file_open(). It's a pity, since, according to some lookup on various search engines and http://codesearch.debian.net/, there's already some userspace code which use O_CLOEXEC: - in systemd's readahead[2]: fanotify_fd = fanotify_init(FAN_CLOEXEC|FAN_NONBLOCK, O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOATIME); - in clsync[3]: #define FANOTIFY_EVFLAGS (O_LARGEFILE|O_RDONLY|O_CLOEXEC) int fanotify_d = fanotify_init(FANOTIFY_FLAGS, FANOTIFY_EVFLAGS); - in examples [4] from "Filesystem monitoring in the Linux kernel" article[5] by Aleksander Morgado: if ((fanotify_fd = fanotify_init (FAN_CLOEXEC, O_RDONLY | O_CLOEXEC | O_LARGEFILE)) < 0) Additionally, since commit 48149e9d3a7e ("fanotify: check file flags passed in fanotify_init"). having O_CLOEXEC as part of fanotify_init() second argument is expressly allowed. So it seems expected to set close-on-exec flag on the file descriptors if userspace is allowed to request it with O_CLOEXEC. But Andrew Morton raised[6] the concern that enabling now close-on-exec might break existing applications which ask for O_CLOEXEC but expect the file descriptor to be inherited across exec(). In the other hand, as reported by Mihai Dontu[7] close-on-exec on the file descriptor returned as part of file access notify can break applications due to deadlock. So close-on-exec is needed for most applications. More, applications asking for close-on-exec are likely expecting it to be enabled, relying on O_CLOEXEC being effective. If not, it might weaken their security, as noted by Jan Kara[8]. So this patch replaces call to macro get_unused_fd() by a call to function get_unused_fd_flags() with event_f_flags value as argument. This way O_CLOEXEC flag in the second argument of fanotify_init(2) syscall is interpreted and close-on-exec get enabled when requested. [1] http://man7.org/linux/man-pages/man2/fanotify_init.2.html [2] http://cgit.freedesktop.org/systemd/systemd/tree/src/readahead/readahead-collect.c?id=v208#n294 [3] https://github.com/xaionaro/clsync/blob/v0.2.1/sync.c#L1631 https://github.com/xaionaro/clsync/blob/v0.2.1/configuration.h#L38 [4] http://www.lanedo.com/~aleksander/fanotify/fanotify-example.c [5] http://www.lanedo.com/2013/filesystem-monitoring-linux-kernel/ [6] http://lkml.kernel.org/r/20141001153621.65e9258e65a6167bf2e4cb50@linux-foundation.org [7] http://lkml.kernel.org/r/20141002095046.3715eb69@mdontu-l [8] http://lkml.kernel.org/r/20141002104410.GB19748@quack.suse.cz Link: http://lkml.kernel.org/r/cover.1411562410.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed by: Heinrich Schuchardt <xypron.glpk@gmx.de> Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Mihai Don\u021bu <mihai.dontu@gmail.com> Cc: Pádraig Brady <P@draigBrady.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Jan Kara <jack@suse.cz> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Michael Kerrisk-manpages <mtk.manpages@gmail.com> Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Richard Guy Briggs <rgb@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09fsnotify: don't put user context if it was never assignedSasha Levin
On some failure paths we may attempt to free user context even if it wasn't assigned yet. This will cause a NULL ptr deref and a kernel BUG. The path I was looking at is in inotify_new_group(): oevent = kmalloc(sizeof(struct inotify_event_info), GFP_KERNEL); if (unlikely(!oevent)) { fsnotify_destroy_group(group); return ERR_PTR(-ENOMEM); } fsnotify_destroy_group() would get called here, but group->inotify_data.user is only getting assigned later: group->inotify_data.user = get_current_user(); Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09fs/notify/group.c: make fsnotify_final_destroy_group() staticAndrew Morton
No callers outside this file. Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-10fs/notify: don't show f_handle if exportfs_encode_inode_fh failedAndrey Vagin
Currently we handle only ENOSPC. In case of other errors the file_handle variable isn't filled properly and we will show a part of stack. Signed-off-by: Andrey Vagin <avagin@openvz.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-10fsnotify/fdinfo: use named constants instead of hardcoded valuesAndrey Vagin
MAX_HANDLE_SZ is equal to 128, but currently the size of pad is only 64 bytes, so exportfs_encode_inode_fh can return an error. Signed-off-by: Andrey Vagin <avagin@openvz.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-09security: make security_file_set_fowner, f_setown and __f_setown void returnJeff Layton
security_file_set_fowner always returns 0, so make it f_setown and __f_setown void return functions and fix up the error handling in the callers. Cc: linux-security-module@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-08-06list: fix order of arguments for hlist_add_after(_rcu)Ken Helias
All other add functions for lists have the new item as first argument and the position where it is added as second argument. This was changed for no good reason in this function and makes using it unnecessary confusing. The name was changed to hlist_add_behind() to cause unconverted code to generate a compile error instead of using the wrong parameter order. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Ken Helias <kenhelias@firemail.de> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> [intel driver bits] Cc: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> 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 Kara
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 Kara
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>
2014-06-06inotify: convert use of typedef ctl_table to struct ctl_tableJoe Perches
This typedef is unnecessary and should just be removed. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fanotify: check file flags passed in fanotify_initHeinrich Schuchardt
Without this patch fanotify_init does not validate the value passed in event_f_flags. When a fanotify event is read from the fanotify file descriptor a new file descriptor is created where file.f_flags = event_f_flags. Internal and external open flags are stored together in field f_flags of struct file. Hence, an application might create file descriptors with internal flags like FMODE_EXEC, FMODE_NOCMTIME set. Jan Kara and Eric Paris both aggreed that this is a bug and the value of event_f_flags should be checked: https://lkml.org/lkml/2014/4/29/522 https://lkml.org/lkml/2014/4/29/539 This updated patch version considers the comments by Michael Kerrisk in https://lkml.org/lkml/2014/5/4/10 With the patch the value of event_f_flags is checked. When specifying an invalid value error EINVAL is returned. Internal flags are disallowed. File creation flags are disallowed: O_CREAT, O_DIRECTORY, O_EXCL, O_NOCTTY, O_NOFOLLOW, O_TRUNC, and O_TTY_INIT. Flags which do not make sense with fanotify are disallowed: __O_TMPFILE, O_PATH, FASYNC, and O_DIRECT. This leaves us with the following allowed values: O_RDONLY, O_WRONLY, O_RDWR are basic functionality. The are stored in the bits given by O_ACCMODE. O_APPEND is working as expected. The value might be useful in a logging application which appends the current status each time the log is opened. O_LARGEFILE is needed for files exceeding 4GB on 32bit systems. O_NONBLOCK may be useful when monitoring slow devices like tapes. O_NDELAY is equal to O_NONBLOCK except for platform parisc. To avoid code breaking on parisc either both flags should be allowed or none. The patch allows both. __O_SYNC and O_DSYNC may be used to avoid data loss on power disruption. O_NOATIME may be useful to reduce disk activity. O_CLOEXEC may be useful, if separate processes shall be used to scan files. Once this patch is accepted, the fanotify_init.2 manpage has to be updated. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fs/notify/fanotify/fanotify_user.c: fix FAN_MARK_FLUSH flag checkingHeinrich Schuchardt
If fanotify_mark is called with illegal value of arguments flags and marks it usually returns EINVAL. When fanotify_mark is called with FAN_MARK_FLUSH the argument flags is not checked for irrelevant flags like FAN_MARK_IGNORED_MASK. The patch removes this inconsistency. If an irrelevant flag is set error EINVAL is returned. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fs/notify/mark.c: trivial cleanupDavid Cohen
Do not initialize private_destroy_list twice. list_replace_init() already takes care of initializing private_destroy_list. We don't need to initialize it with LIST_HEAD() beforehand. Signed-off-by: David Cohen <david.a.cohen@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fanotify: FAN_MARK_FLUSH: avoid having to provide a fake/invalid fd and pathHeinrich Schuchardt
Originally from Tvrtko Ursulin (https://lkml.org/lkml/2011/1/12/112) Avoid having to provide a fake/invalid fd and path when flushing marks Currently for a group to flush marks it has set it needs to provide a fake or invalid (but resolvable) file descriptor and path when calling fanotify_mark. This patch pulls the flush handling a bit up so file descriptor and path are completely ignored when flushing. I reworked the patch to be applicable again (the signature of fanotify_mark has changed since Tvrtko's work). Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06fanotify: fix -EOVERFLOW with large files on 64-bitWill Woods
On 64-bit systems, O_LARGEFILE is automatically added to flags inside the open() syscall (also openat(), blkdev_open(), etc). Userspace therefore defines O_LARGEFILE to be 0 - you can use it, but it's a no-op. Everything should be O_LARGEFILE by default. But: when fanotify does create_fd() it uses dentry_open(), which skips all that. And userspace can't set O_LARGEFILE in fanotify_init() because it's defined to 0. So if fanotify gets an event regarding a large file, the read() will just fail with -EOVERFLOW. This patch adds O_LARGEFILE to fanotify_init()'s event_f_flags on 64-bit systems, using the same test as open()/openat()/etc. Addresses https://bugzilla.redhat.com/show_bug.cgi?id=696821 Signed-off-by: Will Woods <wwoods@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03fanotify: move unrelated handling from copy_event_to_user()Jan Kara
Move code moving event structure to access_list from copy_event_to_user() to fanotify_read() where it is more logical (so that we can immediately see in the main loop that we either move the event to a different list or free it). Also move special error handling for permission events from copy_event_to_user() to the main loop to have it in one place with error handling for normal events. This makes copy_event_to_user() really only copy the event to user without any side effects. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-04-03fanotify: reorganize loop in fanotify_read()Jan Kara
Swap the error / "read ok" branches in the main loop of fanotify_read(). We will grow the "read ok" part in the next patch and this makes the indentation easier. Also it is more common to have error conditions inside an 'if' instead of the fast path. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-04-03fanotify: convert access_mutex to spinlockJan Kara
access_mutex is used only to guard operations on access_list. There's no need for sleeping within this lock so just make a spinlock out of it. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-04-03fanotify: use fanotify event structure for permission response processingJan Kara
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>
2014-04-03fanotify: remove useless bypass_perm checkJan Kara
The prepare_for_access_response() function checks whether group->fanotify_data.bypass_perm is set. However this test can never be true because prepare_for_access_response() is called only from fanotify_read() which means fanotify group is alive with an active fd while bypass_perm is set from fanotify_release() when all file descriptors pointing to the group are closed and the group is going away. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> 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>
2014-02-25fsnotify: Allocate overflow events with proper typeJan Kara
Commit 7053aee26a35 "fsnotify: do not share events between notification groups" used overflow event statically allocated in a group with the size of the generic notification event. This causes problems because some code looks at type specific parts of event structure and gets confused by a random data it sees there and causes crashes. Fix the problem by allocating overflow event with type corresponding to the group type so code cannot get confused. Signed-off-by: Jan Kara <jack@suse.cz>
2014-02-25fanotify: Handle overflow in case of permission eventsJan Kara
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>
2014-02-25fsnotify: Fix detection whether overflow event is queuedJan Kara
Currently we didn't initialize event's list head when we removed it from the event list. Thus a detection whether overflow event is already queued wasn't working. Fix it by always initializing the list head when deleting event from a list. Signed-off-by: Jan Kara <jack@suse.cz>
2014-02-18inotify: Fix reporting of cookies for inotify eventsJan Kara
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 Kara
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 Kara
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 Kara
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>
2014-01-27compat: fix sys_fanotify_markHeiko Carstens
Commit 91c2e0bcae72 ("unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE") added a new unified compat fanotify_mark syscall to be used by all architectures. Unfortunately the unified version merges the split mask parameter in a wrong way: the lower and higher word got swapped. This was discovered with glibc's tst-fanotify test case. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-by: Andreas Krebbel <krebbel@linux.vnet.ibm.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21fsnotify: remove pointless NULL initializersJan Kara
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 Kara
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 Kara
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>
2014-01-21inotify: provide function for name length roundingJan Kara
Rounding of name length when passing it to userspace was done in several places. Provide a function to do it and use it in all places. 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>
2013-07-09fsnotify: update comments concerning locking schemeLino Sanfilippo
There have been changes in the locking scheme of fsnotify but the comments in the source code have not been updated yet. This patch corrects this. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> 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>
2013-07-09inotify: fix race when adding a new watchLino Sanfilippo
In inotify_new_watch() the number of watches for a group is compared against the max number of allowed watches and increased afterwards. The check and incrementation is not done atomically, so it is possible for multiple concurrent threads to pass the check and increment the number of marks above the allowed max. This patch uses an inotify groups mark_lock to ensure that both check and incrementation are done atomic. Furthermore we dont have to worry about the race that allows a concurrent thread to add a watch just after inotify_update_existing_watch() returned with -ENOENT anymore, since this is also synchronized by the groups mark mutex now. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> 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>
2013-07-09dnotify: replace dnotify_mark_mutex with mark mutex of dnotify_groupLino Sanfilippo
There is no need to use a special mutex to protect against the fcntl/close race (see dnotify.c for a description of this race). Instead the dnotify_groups mark mutex can be used. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> 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>
2013-07-09fanotify: put duplicate code for adding vfsmount/inode marks into an own ↵Lino Sanfilippo
function The code under the groups mark_mutex in fanotify_add_inode_mark() and fanotify_add_vfsmount_mark() is almost identical. So put it into a seperate function. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> 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>