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* inotify: only warn once for inotify problemsEric Paris2010-01-151-1/+1
| | | | | | | | | | | inotify will WARN() if it finds that the idr and the fsnotify internals somehow got out of sync. It was only supposed to do this once but due to this stupid bug it would warn every single time a problem was detected. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* inotify: do not reuse watch descriptorsEric Paris2010-01-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 7e790dd5fc937bc8d2400c30a05e32a9e9eef276 ("inotify: fix error paths in inotify_update_watch") inotify changed the manor in which it gave watch descriptors back to userspace. Previous to this commit inotify acted like the following: inotify_add_watch(X, Y, Z) = 1 inotify_rm_watch(X, 1); inotify_add_watch(X, Y, Z) = 2 but after this patch inotify would return watch descriptors like so: inotify_add_watch(X, Y, Z) = 1 inotify_rm_watch(X, 1); inotify_add_watch(X, Y, Z) = 1 which I saw as equivalent to opening an fd where open(file) = 1; close(1); open(file) = 1; seemed perfectly reasonable. The issue is that quite a bit of userspace apparently relies on the behavior in which watch descriptors will not be quickly reused. KDE relies on it, I know some selinux packages rely on it, and I have heard complaints from other random sources such as debian bug 558981. Although the man page implies what we do is ok, we broke userspace so this patch almost reverts us to the old behavior. It is still slightly racey and I have patches that would fix that, but they are rather large and this will fix it for all real world cases. The race is as follows: - task1 creates a watch and blocks in idr_new_watch() before it updates the hint. - task2 creates a watch and updates the hint. - task1 updates the hint with it's older wd - task removes the watch created by task2 - task adds a new watch and will reuse the wd originally given to task2 it requires moving some locking around the hint (last_wd) but this should solve it for the real world and be -stable safe. As a side effect this patch papers over a bug in the lib/idr code which is causing a large number WARN's to pop on people's system and many reports in kerneloops.org. I'm working on the root cause of that idr bug seperately but this should make inotify immune to that issue. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* switch alloc_file() to passing struct pathAl Viro2009-12-161-2/+6
| | | | | | | ... and have the caller grab both mnt and dentry; kill leak in infiniband, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switched inotify_init1() to alloc_file()Al Viro2009-12-161-15/+10
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-12-091-4/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits) tree-wide: fix misspelling of "definition" in comments reiserfs: fix misspelling of "journaled" doc: Fix a typo in slub.txt. inotify: remove superfluous return code check hdlc: spelling fix in find_pvc() comment doc: fix regulator docs cut-and-pasteism mtd: Fix comment in Kconfig doc: Fix IRQ chip docs tree-wide: fix assorted typos all over the place drivers/ata/libata-sff.c: comment spelling fixes fix typos/grammos in Documentation/edac.txt sysctl: add missing comments fs/debugfs/inode.c: fix comment typos sgivwfb: Make use of ARRAY_SIZE. sky2: fix sky2_link_down copy/paste comment error tree-wide: fix typos "couter" -> "counter" tree-wide: fix typos "offest" -> "offset" fix kerneldoc for set_irq_msi() spidev: fix double "of of" in comment comment typo fix: sybsystem -> subsystem ...
| * inotify: remove superfluous return code checkGiuseppe Scrivano2009-12-041-4/+0
| | | | | | | | | | Signed-off-by: Giuseppe Scrivano <gscrivano@gnu.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | sysctl: Drop & in front of every proc_handler.Eric W. Biederman2009-11-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | For consistency drop & in front of every proc_handler. Explicity taking the address is unnecessary and it prevents optimizations like stubbing the proc_handlers to NULL. Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joe Perches <joe@perches.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | sysctl fs: Remove dead binary sysctl supportEric W. Biederman2009-11-121-7/+1
|/ | | | | | | | Now that sys_sysctl is a generic wrapper around /proc/sys .ctl_name and .strategy members of sysctl tables are dead code. Remove them. Cc: Jan Harkes <jaharkes@cs.cmu.edu> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* dnotify: ignore FS_EVENT_ON_CHILDAndreas Gruenbacher2009-10-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mask off FS_EVENT_ON_CHILD in dnotify_handle_event(). Otherwise, when there is more than one watch on a directory and dnotify_should_send_event() succeeds, events with FS_EVENT_ON_CHILD set will trigger all watches and cause spurious events. This case was overlooked in commit e42e2773. #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <signal.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h> static void create_event(int s, siginfo_t* si, void* p) { printf("create\n"); } static void delete_event(int s, siginfo_t* si, void* p) { printf("delete\n"); } int main (void) { struct sigaction action; char *tmpdir, *file; int fd1, fd2; sigemptyset (&action.sa_mask); action.sa_flags = SA_SIGINFO; action.sa_sigaction = create_event; sigaction (SIGRTMIN + 0, &action, NULL); action.sa_sigaction = delete_event; sigaction (SIGRTMIN + 1, &action, NULL); # define TMPDIR "/tmp/test.XXXXXX" tmpdir = malloc(strlen(TMPDIR) + 1); strcpy(tmpdir, TMPDIR); mkdtemp(tmpdir); # define TMPFILE "/file" file = malloc(strlen(tmpdir) + strlen(TMPFILE) + 1); sprintf(file, "%s/%s", tmpdir, TMPFILE); fd1 = open (tmpdir, O_RDONLY); fcntl(fd1, F_SETSIG, SIGRTMIN); fcntl(fd1, F_NOTIFY, DN_MULTISHOT | DN_CREATE); fd2 = open (tmpdir, O_RDONLY); fcntl(fd2, F_SETSIG, SIGRTMIN + 1); fcntl(fd2, F_NOTIFY, DN_MULTISHOT | DN_DELETE); if (fork()) { /* This triggers a create event */ creat(file, 0600); /* This triggers a create and delete event (!) */ unlink(file); } else { sleep(1); rmdir(tmpdir); } return 0; } Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: fix coalesce duplicate events into a single event in special caseWei Yongjun2009-10-181-1/+1
| | | | | | | | | | | | | | If we do rename a dir entry, like this: rename("/tmp/ino7UrgoJ.rename1", "/tmp/ino7UrgoJ.rename2") rename("/tmp/ino7UrgoJ.rename2", "/tmp/ino7UrgoJ") The duplicate events should be coalesced into a single event. But those two events do not be coalesced into a single event, due to some bad check in event_compare(). It can not match the two NULL inodes as the same event. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: do not set group for a mark before it is on the i_listEric Paris2009-10-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fsnotify_add_mark is supposed to add a mark to the g_list and i_list and to set the group and inode for the mark. fsnotify_destroy_mark_by_entry uses the fact that ->group != NULL to know if this group should be destroyed or if it's already been done. But fsnotify_add_mark sets the group and inode before it actually adds the mark to the i_list and g_list. This can result in a race in inotify, it requires 3 threads. sys_inotify_add_watch("file") sys_inotify_add_watch("file") sys_inotify_rm_watch([a]) inotify_update_watch() inotify_new_watch() inotify_add_to_idr() ^--- returns wd = [a] inotfiy_update_watch() inotify_new_watch() inotify_add_to_idr() fsnotify_add_mark() ^--- returns wd = [b] returns to userspace; inotify_idr_find([a]) ^--- gives us the pointer from task 1 fsnotify_add_mark() ^--- this is going to set the mark->group and mark->inode fields, but will return -EEXIST because of the race with [b]. fsnotify_destroy_mark() ^--- since ->group != NULL we call back into inotify_freeing_mark() which calls inotify_remove_from_idr([a]) since fsnotify_add_mark() failed we call: inotify_remove_from_idr([a]) <------WHOOPS it's not in the idr, this could have been any entry added later! The fix is to make sure we don't set mark->group until we are sure the mark is on the inode and fsnotify_add_mark will return success. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: update the group mask on mark additionEric Paris2009-08-281-0/+4
| | | | | | | | Seperating the addition and update of marks in inotify resulted in a regression in that inotify never gets events. The inotify group mask is always 0. This mask should be updated any time a new mark is added. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: fix length reporting and size checkingEric Paris2009-08-281-3/+5
| | | | | | | | | 0db501bd0610ee0c0 introduced a regresion in that it now sends a nul terminator but the length accounting when checking for space or reporting to userspace did not take this into account. This corrects all of the rounding logic. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: do not send a block of zeros when no pathname is availableBrian Rogers2009-08-281-3/+5
| | | | | | | | | | | When an event has no pathname, there's no need to pad it with a null byte and therefore generate an inotify_event sized block of zeros. This fixes a regression introduced by commit 0db501bd0610ee0c0aca84d927f90bcccd09e2bd where my system wouldn't finish booting because some process was being confused by this. Signed-off-by: Brian Rogers <brian@xyzw.org> Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: Ensure we alwasy write the terminating NULL.Eric W. Biederman2009-08-271-7/+6
| | | | | | | | | | | | | | | | | Before the rewrite copy_event_to_user always wrote a terqminating '\0' byte to user space after the filename. Since the rewrite that terminating byte was skipped if your filename is exactly a multiple of event_size. Ouch! So add one byte to name_size before we round up and use clear_user to set userspace to zero like /dev/zero does instead of copying the strange nul_inotify_event. I can't quite convince myself len_to_zero will never exceed 16 and even if it doesn't clear_user should be more efficient and a more accurate reflection of what the code is trying to do. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: fix locking around inotify watching in the idrEric Paris2009-08-271-10/+40
| | | | | | | | | The are races around the idr storage of inotify watches. It's possible that a watch could be found from sys_inotify_rm_watch() in the idr, but it could be removed from the idr before that code does it's removal. Move the locking and the refcnt'ing so that these have to happen atomically. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: do not BUG on idr entries at inotify destructionEric Paris2009-08-271-2/+31
| | | | | | | | | If an inotify watch is left in the idr when an fsnotify group is destroyed this will lead to a BUG. This is not a dangerous situation and really indicates a programming bug and leak of memory. This patch changes it to use a WARN and a printk rather than killing people's boxes. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: seperate new watch creation updating existing watchesEric Paris2009-08-271-69/+103
| | | | | | | | There is nothing known wrong with the inotify watch addition/modification but this patch seperates the two code paths to make them each easy to verify as correct. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: start watch descriptor count at 1Eric Paris2009-08-171-1/+1
| | | | | | | | | | | | | | | | | The inotify_add_watch man page specifies that inotify_add_watch() will return a non-negative integer. However, historically the inotify watches started at 1, not at 0. Turns out that the inotifywait program provided by the inotify-tools package doesn't properly handle a 0 watch descriptor. In 7e790dd5 we changed from starting at 1 to starting at 0. This patch starts at 1, just like in previous kernels, but also just like in previous kernels it's possible for it to wrap back to 0. This preserves the kernel functionality exactly like it was before the patch (neither method broke the spec) Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* inotify: tail drop inotify q_overflow eventsEric Paris2009-08-171-0/+4
| | | | | | | | | | | In f44aebcc the tail drop logic of events with no file backing (q_overflow and in_ignored) was reversed so IN_IGNORED events would never be tail dropped. This now means that Q_OVERFLOW events are NOT tail dropped. The fix is to not tail drop IN_IGNORED, but to tail drop Q_OVERFLOW. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* notify: unused event private raceEric Paris2009-08-173-14/+13
| | | | | | | | | | | | inotify decides if private data it passed to get added to an event was used by checking list_empty(). But it's possible that the event may have been dequeued and the private event removed so it would look empty. The fix is to use the return code from fsnotify_add_notify_event rather than looking at the list. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* inotify: use GFP_NOFS under potential memory pressureEric Paris2009-07-213-11/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inotify can have a watchs removed under filesystem reclaim. ================================= [ INFO: inconsistent lock state ] 2.6.31-rc2 #16 --------------------------------- inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage. khubd/217 [HC0[0]:SC0[0]:HE1:SE1] takes: (iprune_mutex){+.+.?.}, at: [<c10ba899>] invalidate_inodes+0x20/0xe3 {IN-RECLAIM_FS-W} state was registered at: [<c10536ab>] __lock_acquire+0x2c9/0xac4 [<c1053f45>] lock_acquire+0x9f/0xc2 [<c1308872>] __mutex_lock_common+0x2d/0x323 [<c1308c00>] mutex_lock_nested+0x2e/0x36 [<c10ba6ff>] shrink_icache_memory+0x38/0x1b2 [<c108bfb6>] shrink_slab+0xe2/0x13c [<c108c3e1>] kswapd+0x3d1/0x55d [<c10449b5>] kthread+0x66/0x6b [<c1003fdf>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff Two things are needed to fix this. First we need a method to tell fsnotify_create_event() to use GFP_NOFS and second we need to stop using one global IN_IGNORED event and allocate them one at a time. This solves current issues with multiple IN_IGNORED on a queue having tail drop problems and simplifies the allocations since we don't have to worry about two tasks opperating on the IGNORED event concurrently. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: fix inotify tail drop check with path entriesEric Paris2009-07-211-0/+1
| | | | | | | | | | | | fsnotify drops new events when they are the same as the tail event on the queue to be sent to userspace. The problem is that if the event comes with a path we forget to break out of the switch statement and fall into the code path which matches on events that do not have any type of file backed information (things like IN_UNMOUNT and IN_Q_OVERFLOW). The problem is that this code thinks all such events should be dropped. Fix is to add a break. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: check filename before dropping repeat eventsEric Paris2009-07-211-2/+7
| | | | | | | | | | | | | | | | | | | | inotify drops events if the last event on the queue is the same as the current event. But it does 2 things wrong. First it is comparing old->inode with new->inode. But after an event if put on the queue the ->inode is no longer allowed to be used. It's possible between the last event and this new event the inode could be reused and we would falsely match the inode's memory address between two differing events. The second problem is that when a file is removed fsnotify is passed the negative dentry for the removed object rather than the postive dentry from immediately before the removal. This mean the (broken) inotify tail drop code was matching the NULL ->inode of differing events. The fix is to check the file name which is stored with events when doing the tail drop instead of wrongly checking the address of the stored ->inode. Reported-by: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: use def_bool in kconfig instead of letting the user chooseEric Paris2009-07-213-13/+3
| | | | | | | | | | | fsnotify doens't give the user anything. If someone chooses inotify or dnotify it should build fsnotify, if they don't select one it shouldn't be built. This patch changes fsnotify to be a def_bool=n and makes everything else select it. Also fixes the issue people complained about on lwn where gdm hung because they didn't have inotify and they didn't get the inotify build option..... Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: fix error paths in inotify_update_watchEric Paris2009-07-211-30/+49
| | | | | | | | | | | inotify_update_watch could leave things in a horrid state on a number of error paths. We could try to remove idr entries that didn't exist, we could send an IN_IGNORED to userspace for watches that don't exist, and a bit of other stupidity. Clean these up by doing the idr addition before we put the mark on the inode since we can clean that up on error and getting off the inode's mark list is hard. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: do not leak inode marks in inotify_add_watchEric Paris2009-07-211-4/+10
| | | | | | | | | | | | | inotify_add_watch had a couple of problems. The biggest being that if inotify_add_watch was called on the same inode twice (to update or change the event mask) a refence was taken on the original inode mark by fsnotify_find_mark_entry but was not being dropped at the end of the inotify_add_watch call. Thus if inotify_rm_watch was called although the mark was removed from the inode, the refcnt wouldn't hit zero and we would leak memory. Reported-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: drop user watch count when a watch is removedEric Paris2009-07-211-0/+2
| | | | | | | | | The inotify rewrite forgot to drop the inotify watch use cound when a watch was removed. This means that a single inotify fd can only ever register a maximum of /proc/sys/fs/max_user_watches even if some of those had been freed. Signed-off-by: Eric Paris <eparis@redhat.com>
* fs/notify/inotify: decrement user inotify count on closeKeith Packard2009-07-021-0/+3
| | | | | | | | | The per-user inotify_devs value is incremented each time a new file is allocated, but never decremented. This led to inotify_init failing after a limited number of calls. Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: inotify_destroy_mark_entry could get called twiceEric Paris2009-06-193-29/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inotify_destroy_mark_entry could get called twice for the same mark since it is called directly in inotify_rm_watch and when the mark is being destroyed for another reason. As an example assume that the file being watched was just deleted so inotify_destroy_mark_entry would get called from the path fsnotify_inoderemove() -> fsnotify_destroy_marks_by_inode() -> fsnotify_destroy_mark_entry() -> inotify_destroy_mark_entry(). If this happened at the same time as userspace tried to remove a watch via inotify_rm_watch we could attempt to remove the mark from the idr twice and could thus double dec the ref cnt and potentially could be in a use after free/double free situation. The fix is to have inotify_rm_watch use the generic recursive safe fsnotify_destroy_mark_by_entry() so we are sure the inotify_destroy_mark_entry() function can only be called one. This patch also renames the function to inotify_ingored_remove_idr() so it is clear what is actually going on in the function. Hopefully this fixes: [ 20.342058] idr_remove called for id=20 which is not allocated. [ 20.348000] Pid: 1860, comm: udevd Not tainted 2.6.30-tip #1077 [ 20.353933] Call Trace: [ 20.356410] [<ffffffff811a82b7>] idr_remove+0x115/0x18f [ 20.361737] [<ffffffff8134259d>] ? _spin_lock+0x6d/0x75 [ 20.367061] [<ffffffff8111640a>] ? inotify_destroy_mark_entry+0xa3/0xcf [ 20.373771] [<ffffffff8111641e>] inotify_destroy_mark_entry+0xb7/0xcf [ 20.380306] [<ffffffff81115913>] inotify_freeing_mark+0xe/0x10 [ 20.386238] [<ffffffff8111410d>] fsnotify_destroy_mark_by_entry+0x143/0x170 [ 20.393293] [<ffffffff811163a3>] inotify_destroy_mark_entry+0x3c/0xcf [ 20.399829] [<ffffffff811164d1>] sys_inotify_rm_watch+0x9b/0xc6 [ 20.405850] [<ffffffff8100bcdb>] system_call_fastpath+0x16/0x1b Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Eric Paris <eparis@redhat.com> Tested-by: Peter Ziljlstra <peterz@infradead.org>
* fsnotify: allow groups to set freeing_mark to nullEric Paris2009-06-112-8/+3
| | | | | | | | Most fsnotify listeners (all but inotify) do not care about marks being freed. Allow groups to set freeing_mark to null and do not call any function if it is set that way. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify/dnotify: should_send_event shouldn't match on FS_EVENT_ON_CHILDEric Paris2009-06-113-3/+7
| | | | | | | | inotify and dnotify will both indicate that they want any event which came from a child inode. The fix is to mask off FS_EVENT_ON_CHILD when deciding if inotify or dnotify is interested in a given event. Signed-off-by: Eric Paris <eparis@redhat.com>
* dnotify: do not bother to lock entry->lock when reading maskEric Paris2009-06-111-2/+1
| | | | | | | | | entry->lock is needed to make sure entry->mask does not change while manipulating it. In dnotify_should_send_event() we don't care if we get an old or a new mask value out of this entry so there is no point it taking the lock. Signed-off-by: Eric Paris <eparis@redhat.com>
* dnotify: do not use ?true:false when assigning to a boolEric Paris2009-06-111-1/+1
| | | | | | | dnotify_should send event assigned a bool using ?true:false when computing a bit operation. This is poitless and the bool type does this for us. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: reimplement inotify using fsnotifyEric Paris2009-06-115-447/+570
| | | | | | | | | | | | Reimplement inotify_user using fsnotify. This should be feature for feature exactly the same as the original inotify_user. This does not make any changes to the in kernel inotify feature used by audit. Those patches (and the eventual removal of in kernel inotify) will come after the new inotify_user proves to be working correctly. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: handle filesystem unmounts with fsnotify marksEric Paris2009-06-111-0/+72
| | | | | | | | | | When an fs is unmounted with an fsnotify mark entry attached to one of its inodes we need to destroy that mark entry and we also (like inotify) send an unmount event. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: fsnotify marks on inodes pin them in coreEric Paris2009-06-111-0/+7
| | | | | | | | | | | | | | | | | | | This patch pins any inodes with an fsnotify mark in core. The idea is that as soon as the mark is removed from the inode->fsnotify_mark_entries list the inode will be iput. In reality is doesn't quite work exactly this way. The igrab will happen when the mark is added to an inode, but the iput will happen when the inode pointer is NULL'd inside the mark. It's possible that 2 racing things will try to remove the mark from different directions. One may try to remove the mark because of an explicit request and one might try to remove it because the inode was deleted. It's possible that the removal because of inode deletion will remove the mark from the inode's list, but the removal by explicit request will actually set entry->inode == NULL; and call the iput. This is safe. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: allow groups to add private data to eventsEric Paris2009-06-112-4/+49
| | | | | | | | | | inotify needs per group information attached to events. This patch allows groups to attach private information and implements a callback so that information can be freed when an event is being destroyed. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: add correlations between eventsEric Paris2009-06-112-5/+21
| | | | | | | | | | | As part of the standard inotify events it includes a correlation cookie between two dentry move operations. This patch includes the same behaviour in fsnotify events. It is needed so that inotify userspace can be implemented on top of fsnotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: include pathnames with entries when possibleEric Paris2009-06-112-4/+19
| | | | | | | | | | When inotify wants to send events to a directory about a child it includes the name of the original file. This patch collects that filename and makes it available for notification. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: generic notification queue and waitqEric Paris2009-06-113-7/+241
| | | | | | | | | | | inotify needs to do asyc notification in which event information is stored on a queue until the listener is ready to receive it. This patch implements a generic notification queue for inotify (and later fanotify) to store events to be sent at a later time. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* dnotify: reimplement dnotify using fsnotifyEric Paris2009-06-112-107/+363
| | | | | | | | Reimplement dnotify using fsnotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: parent event notificationEric Paris2009-06-113-0/+113
| | | | | | | | | | | inotify and dnotify both use a similar parent notification mechanism. We add a generic parent notification mechanism to fsnotify for both of these to use. This new machanism also adds the dentry flag optimization which exists for inotify to dnotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: add marks to inodes so groups can interpret how to handle those inodesEric Paris2009-06-115-2/+396
| | | | | | | | | | | | | | | | | This patch creates a way for fsnotify groups to attach marks to inodes. These marks have little meaning to the generic fsnotify infrastructure and thus their meaning should be interpreted by the group that attached them to the inode's list. dnotify and inotify will make use of these markings to indicate which inodes are of interest to their respective groups. But this implementation has the useful property that in the future other listeners could actually use the marks for the exact opposite reason, aka to indicate which inodes it had NO interest in. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: unified filesystem notification backendEric Paris2009-06-117-0/+448
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fsnotify is a backend for filesystem notification. fsnotify does not provide any userspace interface but does provide the basis needed for other notification schemes such as dnotify. fsnotify can be extended to be the backend for inotify or the upcoming fanotify. fsnotify provides a mechanism for "groups" to register for some set of filesystem events and to then deliver those events to those groups for processing. fsnotify has a number of benefits, the first being actually shrinking the size of an inode. Before fsnotify to support both dnotify and inotify an inode had unsigned long i_dnotify_mask; /* Directory notify events */ struct dnotify_struct *i_dnotify; /* for directory notifications */ struct list_head inotify_watches; /* watches on this inode */ struct mutex inotify_mutex; /* protects the watches list But with fsnotify this same functionallity (and more) is done with just __u32 i_fsnotify_mask; /* all events for this inode */ struct hlist_head i_fsnotify_mark_entries; /* marks on this inode */ That's right, inotify, dnotify, and fanotify all in 64 bits. We used that much space just in inotify_watches alone, before this patch set. fsnotify object lifetime and locking is MUCH better than what we have today. inotify locking is incredibly complex. See 8f7b0ba1c8539 as an example of what's been busted since inception. inotify needs to know internal semantics of superblock destruction and unmounting to function. The inode pinning and vfs contortions are horrible. no fsnotify implementers do allocation under locks. This means things like f04b30de3 which (due to an overabundance of caution) changes GFP_KERNEL to GFP_NOFS can be reverted. There are no longer any allocation rules when using or implementing your own fsnotify listener. fsnotify paves the way for fanotify. In brief fanotify is a notification mechanism that delivers the lisener both an 'event' and an open file descriptor to the object in question. This means that fanotify is pathname agnostic. Some on lkml may not care for the original companies or users that pushed for TALPA, but fanotify was designed with flexibility and input for other users in mind. The readahead group expressed interest in fanotify as it could be used to profile disk access on boot without breaking the audit system. The desktop search groups have also expressed interest in fanotify as it solves a number of the race conditions and problems present with managing inotify when more than a limited number of specific files are of interest. fanotify can provide for a userspace access control system which makes it a clean interface for AV vendors to hook without trying to do binary patching on the syscall table, LSM, and everywhere else they do their things today. With this patch series fanotify can be implemented in less than 1200 lines of easy to review code. Almost all of which is the socket based user interface. This patch series builds fsnotify to the point that it can implement dnotify and inotify_user. Patches exist and will be sent soon after acceptance to finish the in kernel inotify conversion (audit) and implement fanotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* inotify: use GFP_NOFS in kernel_event() to work around a lockdep false-positiveWu Fengguang2009-05-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is what we believe to be a false positive reported by lockdep. inotify_inode_queue_event() => take inotify_mutex => kernel_event() => kmalloc() => SLOB => alloc_pages_node() => page reclaim => slab reclaim => dcache reclaim => inotify_inode_is_dead => take inotify_mutex => deadlock The plan is to fix this via lockdep annotation, but that is proving to be quite involved. The patch flips the allocation over to GFP_NFS to shut the warning up, for the 2.6.30 release. Hopefully we will fix this for real in 2.6.31. I'll queue a patch in -mm to switch it back to GFP_KERNEL so we don't forget. ================================= [ INFO: inconsistent lock state ] 2.6.30-rc2-next-20090417 #203 --------------------------------- inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. kswapd0/380 [HC0[0]:SC0[0]:HE1:SE1] takes: (&inode->inotify_mutex){+.+.?.}, at: [<ffffffff8112f1b5>] inotify_inode_is_dead+0x35/0xb0 {RECLAIM_FS-ON-W} state was registered at: [<ffffffff81079188>] mark_held_locks+0x68/0x90 [<ffffffff810792a5>] lockdep_trace_alloc+0xf5/0x100 [<ffffffff810f5261>] __kmalloc_node+0x31/0x1e0 [<ffffffff81130652>] kernel_event+0xe2/0x190 [<ffffffff81130826>] inotify_dev_queue_event+0x126/0x230 [<ffffffff8112f096>] inotify_inode_queue_event+0xc6/0x110 [<ffffffff8110444d>] vfs_create+0xcd/0x140 [<ffffffff8110825d>] do_filp_open+0x88d/0xa20 [<ffffffff810f6b68>] do_sys_open+0x98/0x140 [<ffffffff810f6c50>] sys_open+0x20/0x30 [<ffffffff8100c272>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff irq event stamp: 690455 hardirqs last enabled at (690455): [<ffffffff81564fe4>] _spin_unlock_irqrestore+0x44/0x80 hardirqs last disabled at (690454): [<ffffffff81565372>] _spin_lock_irqsave+0x32/0xa0 softirqs last enabled at (690178): [<ffffffff81052282>] __do_softirq+0x202/0x220 softirqs last disabled at (690157): [<ffffffff8100d50c>] call_softirq+0x1c/0x50 other info that might help us debug this: 2 locks held by kswapd0/380: #0: (shrinker_rwsem){++++..}, at: [<ffffffff810d0bd7>] shrink_slab+0x37/0x180 #1: (&type->s_umount_key#17){++++..}, at: [<ffffffff8110cfbf>] shrink_dcache_memory+0x11f/0x1e0 stack backtrace: Pid: 380, comm: kswapd0 Not tainted 2.6.30-rc2-next-20090417 #203 Call Trace: [<ffffffff810789ef>] print_usage_bug+0x19f/0x200 [<ffffffff81018bff>] ? save_stack_trace+0x2f/0x50 [<ffffffff81078f0b>] mark_lock+0x4bb/0x6d0 [<ffffffff810799e0>] ? check_usage_forwards+0x0/0xc0 [<ffffffff8107b142>] __lock_acquire+0xc62/0x1ae0 [<ffffffff810f478c>] ? slob_free+0x10c/0x370 [<ffffffff8107c0a1>] lock_acquire+0xe1/0x120 [<ffffffff8112f1b5>] ? inotify_inode_is_dead+0x35/0xb0 [<ffffffff81562d43>] mutex_lock_nested+0x63/0x420 [<ffffffff8112f1b5>] ? inotify_inode_is_dead+0x35/0xb0 [<ffffffff8112f1b5>] ? inotify_inode_is_dead+0x35/0xb0 [<ffffffff81012fe9>] ? sched_clock+0x9/0x10 [<ffffffff81077165>] ? lock_release_holdtime+0x35/0x1c0 [<ffffffff8112f1b5>] inotify_inode_is_dead+0x35/0xb0 [<ffffffff8110c9dc>] dentry_iput+0xbc/0xe0 [<ffffffff8110cb23>] d_kill+0x33/0x60 [<ffffffff8110ce23>] __shrink_dcache_sb+0x2d3/0x350 [<ffffffff8110cffa>] shrink_dcache_memory+0x15a/0x1e0 [<ffffffff810d0cc5>] shrink_slab+0x125/0x180 [<ffffffff810d1540>] kswapd+0x560/0x7a0 [<ffffffff810ce160>] ? isolate_pages_global+0x0/0x2c0 [<ffffffff81065a30>] ? autoremove_wake_function+0x0/0x40 [<ffffffff8107953d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff810d0fe0>] ? kswapd+0x0/0x7a0 [<ffffffff8106555b>] kthread+0x5b/0xa0 [<ffffffff8100d40a>] child_rip+0xa/0x20 [<ffffffff8100cdd0>] ? restore_args+0x0/0x30 [<ffffffff81065500>] ? kthread+0x0/0xa0 [<ffffffff8100d400>] ? child_rip+0x0/0x20 [eparis@redhat.com: fix audit too] Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matt Mackall <mpm@selenic.com> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Eric Paris <eparis@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: avoid I_NEW inodesNick Piggin2009-03-271-8/+8
| | | | | | | | | | | | | | | | | | To be on the safe side, it should be less fragile to exclude I_NEW inodes from inode list scans by default (unless there is an important reason to have them). Normally they will get excluded (eg. by zero refcount or writecount etc), however it is a bit fragile for list walkers to know exactly what parts of the inode state is set up and valid to test when in I_NEW. So along these lines, move I_NEW checks upward as well (sometimes taking I_FREEING etc checks with them too -- this shouldn't be a problem should it?) Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* inotify: fix GFP_KERNEL related deadlockIngo Molnar2009-02-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enhanced lockdep coverage of __GFP_NOFS turned up this new lockdep assert: [ 1093.677775] [ 1093.677781] ================================= [ 1093.680031] [ INFO: inconsistent lock state ] [ 1093.680031] 2.6.29-rc5-tip-01504-gb49eca1-dirty #1 [ 1093.680031] --------------------------------- [ 1093.680031] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. [ 1093.680031] kswapd0/308 [HC0[0]:SC0[0]:HE1:SE1] takes: [ 1093.680031] (&inode->inotify_mutex){+.+.?.}, at: [<c0205942>] inotify_inode_is_dead+0x20/0x80 [ 1093.680031] {RECLAIM_FS-ON-W} state was registered at: [ 1093.680031] [<c01696b9>] mark_held_locks+0x43/0x5b [ 1093.680031] [<c016baa4>] lockdep_trace_alloc+0x6c/0x6e [ 1093.680031] [<c01cf8b0>] kmem_cache_alloc+0x20/0x150 [ 1093.680031] [<c040d0ec>] idr_pre_get+0x27/0x6c [ 1093.680031] [<c02056e3>] inotify_handle_get_wd+0x25/0xad [ 1093.680031] [<c0205f43>] inotify_add_watch+0x7a/0x129 [ 1093.680031] [<c020679e>] sys_inotify_add_watch+0x20f/0x250 [ 1093.680031] [<c010389e>] sysenter_do_call+0x12/0x35 [ 1093.680031] [<ffffffff>] 0xffffffff [ 1093.680031] irq event stamp: 60417 [ 1093.680031] hardirqs last enabled at (60417): [<c018d5f5>] call_rcu+0x53/0x59 [ 1093.680031] hardirqs last disabled at (60416): [<c018d5b9>] call_rcu+0x17/0x59 [ 1093.680031] softirqs last enabled at (59656): [<c0146229>] __do_softirq+0x157/0x16b [ 1093.680031] softirqs last disabled at (59651): [<c0106293>] do_softirq+0x74/0x15d [ 1093.680031] [ 1093.680031] other info that might help us debug this: [ 1093.680031] 2 locks held by kswapd0/308: [ 1093.680031] #0: (shrinker_rwsem){++++..}, at: [<c01b0502>] shrink_slab+0x36/0x189 [ 1093.680031] #1: (&type->s_umount_key#4){+++++.}, at: [<c01e6d77>] shrink_dcache_memory+0x110/0x1fb [ 1093.680031] [ 1093.680031] stack backtrace: [ 1093.680031] Pid: 308, comm: kswapd0 Not tainted 2.6.29-rc5-tip-01504-gb49eca1-dirty #1 [ 1093.680031] Call Trace: [ 1093.680031] [<c016947a>] valid_state+0x12a/0x13d [ 1093.680031] [<c016954e>] mark_lock+0xc1/0x1e9 [ 1093.680031] [<c016a5b4>] ? check_usage_forwards+0x0/0x3f [ 1093.680031] [<c016ab74>] __lock_acquire+0x2c6/0xac8 [ 1093.680031] [<c01688d9>] ? register_lock_class+0x17/0x228 [ 1093.680031] [<c016b3d3>] lock_acquire+0x5d/0x7a [ 1093.680031] [<c0205942>] ? inotify_inode_is_dead+0x20/0x80 [ 1093.680031] [<c08824c4>] __mutex_lock_common+0x3a/0x4cb [ 1093.680031] [<c0205942>] ? inotify_inode_is_dead+0x20/0x80 [ 1093.680031] [<c08829ed>] mutex_lock_nested+0x2e/0x36 [ 1093.680031] [<c0205942>] ? inotify_inode_is_dead+0x20/0x80 [ 1093.680031] [<c0205942>] inotify_inode_is_dead+0x20/0x80 [ 1093.680031] [<c01e6672>] dentry_iput+0x90/0xc2 [ 1093.680031] [<c01e67a3>] d_kill+0x21/0x45 [ 1093.680031] [<c01e6a46>] __shrink_dcache_sb+0x27f/0x355 [ 1093.680031] [<c01e6dc5>] shrink_dcache_memory+0x15e/0x1fb [ 1093.680031] [<c01b05ed>] shrink_slab+0x121/0x189 [ 1093.680031] [<c01b0d12>] kswapd+0x39f/0x561 [ 1093.680031] [<c01ae499>] ? isolate_pages_global+0x0/0x233 [ 1093.680031] [<c0157eae>] ? autoremove_wake_function+0x0/0x43 [ 1093.680031] [<c01b0973>] ? kswapd+0x0/0x561 [ 1093.680031] [<c0157daf>] kthread+0x41/0x82 [ 1093.680031] [<c0157d6e>] ? kthread+0x0/0x82 [ 1093.680031] [<c01043ab>] kernel_thread_helper+0x7/0x10 inotify_handle_get_wd() does idr_pre_get() which does a kmem_cache_alloc() without __GFP_FS - and is hence deadlockable under extreme MM pressure. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: MinChan Kim <minchan.kim@gmail.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* inotify: clean up inotify_read and fix locking problemsVegard Nossum2009-01-261-61/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If userspace supplies an invalid pointer to a read() of an inotify instance, the inotify device's event list mutex is unlocked twice. This causes an unbalance which effectively leaves the data structure unprotected, and we can trigger oopses by accessing the inotify instance from different tasks concurrently. The best fix (contributed largely by Linus) is a total rewrite of the function in question: On Thu, Jan 22, 2009 at 7:05 AM, Linus Torvalds wrote: > The thing to notice is that: > > - locking is done in just one place, and there is no question about it > not having an unlock. > > - that whole double-while(1)-loop thing is gone. > > - use multiple functions to make nesting and error handling sane > > - do error testing after doing the things you always need to do, ie do > this: > > mutex_lock(..) > ret = function_call(); > mutex_unlock(..) > > .. test ret here .. > > instead of doing conditional exits with unlocking or freeing. > > So if the code is written in this way, it may still be buggy, but at least > it's not buggy because of subtle "forgot to unlock" or "forgot to free" > issues. > > This _always_ unlocks if it locked, and it always frees if it got a > non-error kevent. Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Robert Love <rlove@google.com> Cc: <stable@kernel.org> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CVE-2009-0029] System call wrappers part 29Heiko Carstens2009-01-141-2/+3
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-28 17:44:50 +0000