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* autofs: fix a leak in autofs_expire_indirect()Al Viro2019-12-211-2/+3
| | | | | | | | | | | [ Upstream commit 03ad0d703df75c43f78bd72e16124b5b94a95188 ] if the second call of should_expire() in there ends up grabbing and returning a new reference to dentry, we need to drop it before continuing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* autofs: fix error return in autofs_fill_super()Ian Kent2019-03-131-1/+3
| | | | | | | | | | | | | | [ Upstream commit f585b283e3f025754c45bbe7533fc6e5c4643700 ] In autofs_fill_super() on error of get inode/make root dentry the return should be ENOMEM as this is the only failure case of the called functions. Link: http://lkml.kernel.org/r/154725123240.11260.796773942606871359.stgit@pluto-themaw-net Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* autofs: drop dentry reference only when it is never usedPan Bian2019-03-131-1/+2
| | | | | | | | | | | | | | | | [ Upstream commit 63ce5f552beb9bdb41546b3a26c4374758b21815 ] autofs_expire_run() calls dput(dentry) to drop the reference count of dentry. However, dentry is read via autofs_dentry_ino(dentry) after that. This may result in a use-free-bug. The patch drops the reference count of dentry only when it is never used. Link: http://lkml.kernel.org/r/154725122396.11260.16053424107144453867.stgit@pluto-themaw-net Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* autofs: fix autofs_sbi() does not check super block typeIan Kent2018-09-192-2/+3
| | | | | | | | | | | | | | | | | | | commit 0633da48f0793aeba27f82d30605624416723a91 upstream. autofs_sbi() does not check the superblock magic number to verify it has been given an autofs super block. Backport Note: autofs4 has been renamed to autofs upstream. As a result the upstream patch does not apply cleanly onto 4.14.y. Link: http://lkml.kernel.org/r/153475422934.17131.7563724552005298277.stgit@pluto.themaw.net Reported-by: <syzbot+87c3c541582e56943277@syzkaller.appspotmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Zubin Mithra <zsm@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* autofs: mount point create should honour passed in modeIan Kent2018-04-241-1/+1
| | | | | | | | | | | | | | | | | | | | | commit 1e6306652ba18723015d1b4967fe9de55f042499 upstream. The autofs file system mkdir inode operation blindly sets the created directory mode to S_IFDIR | 0555, ingoring the passed in mode, which can cause selinux dac_override denials. But the function also checks if the caller is the daemon (as no-one else should be able to do anything here) so there's no point in not honouring the passed in mode, allowing the daemon to set appropriate mode when required. Link: http://lkml.kernel.org/r/152361593601.8051.14014139124905996173.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* autofs: fix careless error in recent commitNeilBrown2017-12-201-1/+0
| | | | | | | | | | | | | | | | | | commit 302ec300ef8a545a7fc7f667e5fd743b091c2eeb upstream. Commit ecc0c469f277 ("autofs: don't fail mount for transient error") was meant to replace an 'if' with a 'switch', but instead added the 'switch' leaving the case in place. Link: http://lkml.kernel.org/r/87zi6wstmw.fsf@notabene.neil.brown.name Fixes: ecc0c469f277 ("autofs: don't fail mount for transient error") Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: NeilBrown <neilb@suse.com> Cc: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* autofs: don't fail mount for transient errorNeilBrown2017-11-301-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ecc0c469f27765ed1e2b967be0aa17cee1a60b76 upstream. Currently if the autofs kernel module gets an error when writing to the pipe which links to the daemon, then it marks the whole moutpoint as catatonic, and it will stop working. It is possible that the error is transient. This can happen if the daemon is slow and more than 16 requests queue up. If a subsequent process tries to queue a request, and is then signalled, the write to the pipe will return -ERESTARTSYS and autofs will take that as total failure. So change the code to assess -ERESTARTSYS and -ENOMEM as transient failures which only abort the current request, not the whole mountpoint. It isn't a crash or a data corruption, but having autofs mountpoints suddenly stop working is rather inconvenient. Ian said: : And given the problems with a half dozen (or so) user space applications : consuming large amounts of CPU under heavy mount and umount activity this : could happen more easily than we expect. Link: http://lkml.kernel.org/r/87y3norvgp.fsf@notabene.neil.brown.name Signed-off-by: NeilBrown <neilb@suse.com> Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAILNeilBrown2017-06-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | commit 9fa4eb8e490a28de40964b1b0e583d8db4c7e57c upstream. If a positive status is passed with the AUTOFS_DEV_IOCTL_FAIL ioctl, autofs4_d_automount() will return ERR_PTR(status) with that status to follow_automount(), which will then dereference an invalid pointer. So treat a positive status the same as zero, and map to ENOENT. See comment in systemd src/core/automount.c::automount_send_ready(). Link: http://lkml.kernel.org/r/871sqwczx5.fsf@notabene.neil.brown.name Signed-off-by: NeilBrown <neilb@suse.com> Cc: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs: Better permission checking for submountsEric W. Biederman2017-03-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 93faccbbfa958a9668d3ab4e30f38dd205cee8d8 upstream. To support unprivileged users mounting filesystems two permission checks have to be performed: a test to see if the user allowed to create a mount in the mount namespace, and a test to see if the user is allowed to access the specified filesystem. The automount case is special in that mounting the original filesystem grants permission to mount the sub-filesystems, to any user who happens to stumble across the their mountpoint and satisfies the ordinary filesystem permission checks. Attempting to handle the automount case by using override_creds almost works. It preserves the idea that permission to mount the original filesystem is permission to mount the sub-filesystem. Unfortunately using override_creds messes up the filesystems ordinary permission checks. Solve this by being explicit that a mount is a submount by introducing vfs_submount, and using it where appropriate. vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let sget and friends know that a mount is a submount so they can take appropriate action. sget and sget_userns are modified to not perform any permission checks on submounts. follow_automount is modified to stop using override_creds as that has proven problemantic. do_mount is modified to always remove the new MS_SUBMOUNT flag so that we know userspace will never by able to specify it. autofs4 is modified to stop using current_real_cred that was put in there to handle the previous version of submount permission checking. cifs is modified to pass the mountpoint all of the way down to vfs_submount. debugfs is modified to pass the mountpoint all of the way down to trace_automount by adding a new parameter. To make this change easier a new typedef debugfs_automount_t is introduced to capture the type of the debugfs automount function. Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com> Reviewed-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* autofs: refactor ioctl fn vector in iookup_dev_ioctl()Tomohiro Kusumi2016-10-111-33/+16
| | | | | | | | | | | cmd part of this struct is the same as an index of itself within _ioctls[]. In fact this cmd is unused, so we can drop this part. Link: http://lkml.kernel.org/r/20160831033414.9910.66697.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: remove possibly misleading /* #define DEBUG */Tomohiro Kusumi2016-10-111-2/+0
| | | | | | | | | | | | | | | | | | | Having this in autofs_i.h gives illusion that uncommenting this enables pr_debug(), but it doesn't enable all the pr_debug() in autofs because inclusion order matters. XFS has the same DEBUG macro in its core header fs/xfs/xfs.h, however XFS seems to have a rule to include this prior to other XFS headers as well as kernel headers. This is not the case with autofs, and DEBUG could be enabled via Makefile, so autofs should just get rid of this comment to make the code less confusing. It's a comment, so there is literally no functional difference. Link: http://lkml.kernel.org/r/20160831033409.9910.77067.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: fix print format for ioctl warning messageTomohiro Kusumi2016-10-111-1/+1
| | | | | | | | | | | | | | All other warnings use "cmd(0x%08x)" and this is the only one with "cmd(%d)". (below comes from my userspace debug program, but not automount daemon) [ 1139.905676] autofs4:pid:1640:check_dev_ioctl_version: ioctl control interface version mismatch: kernel(1.0), user(0.0), cmd(-1072131215) Link: http://lkml.kernel.org/r/20160812024851.12352.75458.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: add autofs_dev_ioctl_version() for AUTOFS_DEV_IOCTL_VERSION_CMDIan Kent2016-10-111-8/+17
| | | | | | | | | | | | | | | | | No functional changes, based on the following justification. 1. Make the code more consistent using the ioctl vector _ioctls[], rather than assigning NULL only for this ioctl command. 2. Remove goto done; for better maintainability in the long run. 3. The existing code is based on the fact that validate_dev_ioctl() sets ioctl version for any command, but AUTOFS_DEV_IOCTL_VERSION_CMD should explicitly set it regardless of the default behavior. Link: http://lkml.kernel.org/r/20160812024846.12352.9885.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: fix dev ioctl number range checkIan Kent2016-10-112-2/+3
| | | | | | | | | | | | | | | | The count of miscellaneous device ioctls in fs/autofs4/autofs_i.h is wrong. The number of ioctls is the difference between AUTOFS_DEV_IOCTL_VERSION_CMD and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD (14) not the difference between AUTOFS_IOC_COUNT and 11 (21). [kusumi.tomohiro@gmail.com: fix typo that made the count macro negative] Link: http://lkml.kernel.org/r/20160831033420.9910.16809.stgit@pluto.themaw.net Link: http://lkml.kernel.org/r/20160812024841.12352.11975.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: fix pr_debug() messageTomohiro Kusumi2016-10-111-1/+1
| | | | | | | | | | | | | This isn't a return value, so change the message to indicate the status is the result of may_umount(). (or locate pr_debug() after put_user() with the same message) Link: http://lkml.kernel.org/r/20160812024836.12352.74628.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: don't fail to free_dev_ioctl(param)Tomohiro Kusumi2016-10-111-1/+2
| | | | | | | | | | Returning -ENOTTY here fails to free dynamically allocated param. Link: http://lkml.kernel.org/r/20160812024815.12352.69153.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: remove obsolete sb fieldsTomohiro Kusumi2016-10-111-2/+0
| | | | | | | | | | | These two were left from commit aa55ddf340c9 ("autofs4: remove unused ioctls") which removed unused ioctls. Link: http://lkml.kernel.org/r/20160812024810.12352.96377.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <ikent@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: use autofs4_free_ino() to kfree dentry dataTomohiro Kusumi2016-10-111-1/+1
| | | | | | | | | | | | | | kfree dentry data allocated by autofs4_new_ino() with autofs4_free_ino() instead of raw kfree. (since we have the interface to free autofs_info*) This patch was modified to remove the need to set the dentry info field to NULL dew to a change in the previous patch. Link: http://lkml.kernel.org/r/20160812024805.12352.43650.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: remove ino free in autofs4_dir_symlink()Ian Kent2016-10-111-2/+0
| | | | | | | | | | | | | | The inode allocation failure case in autofs4_dir_symlink() frees the autofs dentry info of the dentry without setting ->d_fsdata to NULL. That could lead to a double free so just get rid of the free and leave it to ->d_release(). Link: http://lkml.kernel.org/r/20160812024759.12352.10653.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: add WARN_ON(1) for non dir/link inode caseTomohiro Kusumi2016-10-111-1/+2
| | | | | | | | | | | It's invalid if the given mode is neither dir nor link, so warn on else case. Link: http://lkml.kernel.org/r/20160812024754.12352.8536.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: fix autofs4_fill_super() error exit handlingIan Kent2016-10-111-3/+3
| | | | | | | | | | Somewhere along the line the error handling gotos have become incorrect. Link: http://lkml.kernel.org/r/20160812024749.12352.15100.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: test autofs versions first on sb initializationTomohiro Kusumi2016-10-111-17/+17
| | | | | | | | | | | | | | This patch does what the below comment says. It could be and it's considered better to do this first before various functions get called during initialization. /* Couldn't this be tested earlier? */ Link: http://lkml.kernel.org/r/20160812024744.12352.43075.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* autofs: drop unnecessary extern in autofs_i.hTomohiro Kusumi2016-10-111-1/+1
| | | | | | | | | | | autofs4_kill_sb() doesn't need to be declared as extern, and no other functions in .h are explicitly declared as extern. Link: http://lkml.kernel.org/r/20160812024739.12352.99354.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2016-10-102-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
| * Merge remote-tracking branch 'ovl/rename2' into for-linusAl Viro2016-10-101-13/+42
| |\
| * | fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani2016-09-272-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2016-10-061-2/+2
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This set of changes is a number of smaller things that have been overlooked in other development cycles focused on more fundamental change. The devpts changes are small things that were a distraction until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an trivial regression fix to autofs for the unprivileged mount changes that went in last cycle. A pair of ioctls has been added by Andrey Vagin making it is possible to discover the relationships between namespaces when referring to them through file descriptors. The big user visible change is starting to add simple resource limits to catch programs that misbehave. With namespaces in general and user namespaces in particular allowing users to use more kinds of resources, it has become important to have something to limit errant programs. Because the purpose of these limits is to catch errant programs the code needs to be inexpensive to use as it always on, and the default limits need to be high enough that well behaved programs on well behaved systems don't encounter them. To this end, after some review I have implemented per user per user namespace limits, and use them to limit the number of namespaces. The limits being per user mean that one user can not exhause the limits of another user. The limits being per user namespace allow contexts where the limit is 0 and security conscious folks can remove from their threat anlysis the code used to manage namespaces (as they have historically done as it root only). At the same time the limits being per user namespace allow other parts of the system to use namespaces. Namespaces are increasingly being used in application sand boxing scenarios so an all or nothing disable for the entire system for the security conscious folks makes increasing use of these sandboxes impossible. There is also added a limit on the maximum number of mounts present in a single mount namespace. It is nontrivial to guess what a reasonable system wide limit on the number of mount structure in the kernel would be, especially as it various based on how a system is using containers. A limit on the number of mounts in a mount namespace however is much easier to understand and set. In most cases in practice only about 1000 mounts are used. Given that some autofs scenarious have the potential to be 30,000 to 50,000 mounts I have set the default limit for the number of mounts at 100,000 which is well above every known set of users but low enough that the mount hash tables don't degrade unreaonsably. These limits are a start. I expect this estabilishes a pattern that other limits for resources that namespaces use will follow. There has been interest in making inotify event limits per user per user namespace as well as interest expressed in making details about what is going on in the kernel more visible" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits) autofs: Fix automounts by using current_real_cred()->uid mnt: Add a per mount namespace limit on the number of mounts netns: move {inc,dec}_net_namespaces into #ifdef nsfs: Simplify __ns_get_path tools/testing: add a test to check nsfs ioctl-s nsfs: add ioctl to get a parent namespace nsfs: add ioctl to get an owning user namespace for ns file descriptor kernel: add a helper to get an owning user namespace for a namespace devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts devpts: Remove sync_filesystems devpts: Make devpts_kill_sb safe if fsi is NULL devpts: Simplify devpts_mount by using mount_nodev devpts: Move the creation of /dev/pts/ptmx into fill_super devpts: Move parse_mount_options into fill_super userns: When the per user per user namespace limit is reached return ENOSPC userns; Document per user per user namespace limits. mntns: Add a limit on the number of mount namespaces. netns: Add a limit on the number of net namespaces cgroupns: Add a limit on the number of cgroup namespaces ipcns: Add a limit on the number of ipc namespaces ...
| * | autofs: Fix automounts by using current_real_cred()->uidEric W. Biederman2016-09-301-2/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Seth Forshee reports that in 4.8-rcN some automounts are failing because the requesting the automount changed. The relevant call path is: follow_automount() ->d_automount autofs4_d_automount autofs4_mount_wait autofs4_wait In autofs4_wait wq_uid and wq_gid are set to current_uid() and current_gid respectively. With follow_automount now overriding creds uid that we export to userspace changes and that breaks existing setups. To remove the regression set wq_uid and wq_gid from current_real_cred()->uid and current_real_cred()->gid respectively. This restores the current behavior as current->real_cred is identical to current->cred except when override creds are used. Cc: stable@vger.kernel.org Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Reported-by: Seth Forshee <seth.forshee@canonical.com> Tested-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* / autofs: use dentry flags to block walks during expireIan Kent2016-09-191-13/+42
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Somewhere along the way the autofs expire operation has changed to hold a spin lock over expired dentry selection. The autofs indirect mount expired dentry selection is complicated and quite lengthy so it isn't appropriate to hold a spin lock over the operation. Commit 47be61845c77 ("fs/dcache.c: avoid soft-lockup in dput()") added a might_sleep() to dput() causing a WARN_ONCE() about this usage to be issued. But the spin lock doesn't need to be held over this check, the autofs dentry info. flags are enough to block walks into dentrys during the expire. I've left the direct mount expire as it is (for now) because it is much simpler and quicker than the indirect mount expire and adding spin lock release and re-aquires would do nothing more than add overhead. Fixes: 47be61845c77 ("fs/dcache.c: avoid soft-lockup in dput()") Link: http://lkml.kernel.org/r/20160912014017.1773.73060.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Reported-by: Takashi Iwai <tiwai@suse.de> Tested-by: Takashi Iwai <tiwai@suse.de> Cc: Takashi Iwai <tiwai@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Al 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>
* Merge branch 'work.const-qstr' of ↵Linus Torvalds2016-08-062-6/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull qstr constification updates from Al Viro: "Fairly self-contained bunch - surprising lot of places passes struct qstr * as an argument when const struct qstr * would suffice; it complicates analysis for no good reason. I'd prefer to feed that separately from the assorted fixes (those are in #for-linus and with somewhat trickier topology)" * 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: qstr: constify instances in adfs qstr: constify instances in lustre qstr: constify instances in f2fs qstr: constify instances in ext2 qstr: constify instances in vfat qstr: constify instances in procfs qstr: constify instances in fuse qstr constify instances in fs/dcache.c qstr: constify instances in nfs qstr: constify instances in ocfs2 qstr: constify instances in autofs4 qstr: constify instances in hfs qstr: constify instances in hfsplus qstr: constify instances in logfs qstr: constify dentry_init_security
| * qstr: constify instances in autofs4Al Viro2016-07-202-6/+6
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'salted-string-hash'Linus Torvalds2016-07-281-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes the vfs dentry hashing to mix in the parent pointer at the _beginning_ of the hash, rather than at the end. That actually improves both the hash and the code generation, because we can move more of the computation to the "static" part of the dcache setup, and do less at lookup runtime. It turns out that a lot of other hash users also really wanted to mix in a base pointer as a 'salt' for the hash, and so the slightly extended interface ends up working well for other cases too. Users that want a string hash that is purely about the string pass in a 'salt' pointer of NULL. * merge branch 'salted-string-hash': fs/dcache.c: Save one 32-bit multiply in dcache lookup vfs: make the string hashes salt the hash
| * vfs: make the string hashes salt the hashLinus Torvalds2016-06-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We always mixed in the parent pointer into the dentry name hash, but we did it late at lookup time. It turns out that we can simplify that lookup-time action by salting the hash with the parent pointer early instead of late. A few other users of our string hashes also wanted to mix in their own pointers into the hash, and those are updated to use the same mechanism. Hash users that don't have any particular initial salt can just use the NULL pointer as a no-salt. Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs: don't get stuck in a loop if vfs_write() returns an errorAndrey Vagin2016-06-241-3/+4
| | | | | | | | | | | | | | | | | | | | __vfs_write() returns a negative value in a error case. Link: http://lkml.kernel.org/r/20160616083108.6278.65815.stgit@pluto.themaw.net Signed-off-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs racesAl Viro2016-06-123-22/+15
|/ | | | | | | | | | | | | * make autofs4_expire_indirect() skip the dentries being in process of expiry * do *not* mess with list_move(); making sure that dentry with AUTOFS_INF_EXPIRING are not picked for expiry is enough. * do not remove NO_RCU when we set EXPIRING, don't bother with smp_mb() there. Clear it at the same time we clear EXPIRING. Makes a bunch of tests simpler. * rename NO_RCU to WANT_EXPIRE, which is what it really is. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* dcache_{readdir,dir_lseek}() users: switch to ->iterate_sharedAl Viro2016-05-021-2/+2
| | | | | | | no need to lock directory in dcache_dir_lseek(), while we are at it - per-struct file exclusion is enough. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2016-03-191-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: - Preparations of parallel lookups (the remaining main obstacle is the need to move security_d_instantiate(); once that becomes safe, the rest will be a matter of rather short series local to fs/*.c - preadv2/pwritev2 series from Christoph - assorted fixes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits) splice: handle zero nr_pages in splice_to_pipe() vfs: show_vfsstat: do not ignore errors from show_devname method dcache.c: new helper: __d_add() don't bother with __d_instantiate(dentry, NULL) untangle fsnotify_d_instantiate() a bit uninline d_add() replace d_add_unique() with saner primitive quota: use lookup_one_len_unlocked() cifs_get_root(): use lookup_one_len_unlocked() nfs_lookup: don't bother with d_instantiate(dentry, NULL) kill dentry_unhash() ceph_fill_trace(): don't bother with d_instantiate(dn, NULL) autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup() configfs: move d_rehash() into configfs_create() for regular files ceph: don't bother with d_rehash() in splice_dentry() namei: teach lookup_slow() to skip revalidate namei: massage lookup_slow() to be usable by lookup_one_len_unlocked() lookup_one_len_unlocked(): use lookup_dcache() namei: simplify invalidation logics in lookup_dcache() namei: change calling conventions for lookup_{fast,slow} and follow_managed() ...
| * autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()Al Viro2016-03-141-2/+0
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | autofs4: use pr_xxx() macros directly for loggingIan Kent2016-03-156-75/+68
| | | | | | | | | | | | | | | | | | | | Use the standard pr_xxx() log macros directly for log prints instead of the AUTOFS_XXX() macros. Signed-off-by: Ian Kent <ikent@redhat.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs4: change log print macros to not insert newlineIan Kent2016-03-156-49/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | Common kernel coding practice is to include the newline of log prints within the log text rather than hidden away in a macro. To avoid introducing inconsistencies as changes are made change the log macros to not include the newline. Signed-off-by: Ian Kent <raven@themaw.net> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs4: make autofs log prints consistentIan Kent2016-03-154-12/+12
| | | | | | | | | | | | | | | | | | | | | | Use the pr_*() print in AUTOFS_*() macros instead of printks and include the module name in log message macros. Also use the AUTOFS_*() macros everywhere instead of raw printks. Signed-off-by: Ian Kent <raven@themaw.net> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs4: fix some white space errorsIan Kent2016-03-154-8/+6
| | | | | | | | | | | | | | | | Fix some white space format errors. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()Ian Kent2016-03-151-1/+1
| | | | | | | | | | | | | | | | | | The return from an ioctl if an invalid ioctl is passed in should be EINVAL not ENOSYS. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs4: fix coding style line length in autofs4_wait()Ian Kent2016-03-151-2/+4
| | | | | | | | | | | | | | | | | | The need for this is questionable but checkpatch.pl complains about the line length and it's a straightfoward change. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs4: fix coding style problem in autofs4_get_set_timeout()Ian Kent2016-03-151-8/+20
| | | | | | | | | | | | | | | | Refactor autofs4_get_set_timeout() to eliminate coding style error. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs4: coding style fixesIan Kent2016-03-158-158/+175
| | | | | | | | | | | | | | | | | | Try and make the coding style completely consistent throughtout the autofs module and inline with kernel coding style recommendations. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | autofs: show pipe inode in mount optionsStanislav Kinsburskiy2016-03-151-1/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is required for CRIU (Checkpoint Restart In Userspace) to migrate a mount point when write end in user space is closed. Below is a brief description of the problem. To migrate a non-catatonic autofs mount point, one has to restore the control pipe between kernel and autofs master process. One of the autofs masters is systemd, which closes pipe write end after passing it to the kernel with mount call. To be able to restore the systemd control pipe one has to know which read pipe end in systemd corresponds to the write pipe end in the kernel. The pipe "fd" in mount options is not enough because it was closed and probably replaced by some other descriptor. Thus, some other attribute is required to be able to find the read pipe end. The best attribute to use to find the correct pipe end is inode number becuase it's unique for the whole system and can't be reused while the autofs mount exists. This attribute can also be used to recognize a situation where an autofs mount has no master (no process with specified "pgrp" or no file descriptor with "pipe_ino", specified in autofs mount options). Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* switch ->get_link() to delayed_call, kill ->put_link()Al Viro2015-12-301-1/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* replace ->follow_link() with new method that could stay in RCU modeAl Viro2015-12-081-4/+9
| | | | | | | | | | | | | | | | | | new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* make simple_positive() publicAl Viro2015-06-231-5/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>