kernel/linux.git/fs/autofs, branch v6.6.131

Merge tag 'v6.6-vfs.autofs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2023-08-28T18:39:14+00:00

Pull autofs fixes from Christian Brauner: "This fixes a memory leak in autofs reported by syzkaller and a missing conversion from uninterruptible to interruptible wake up when autofs is in catatonic mode" * tag 'v6.6-vfs.autofs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: autofs: use wake_up() instead of wake_up_interruptible(() autofs: fix memory leak of waitqueues in autofs_catatonic_mode

Merge tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2023-08-28T16:31:32+00:00

Pull vfs timestamp updates from Christian Brauner: "This adds VFS support for multi-grain timestamps and converts tmpfs, xfs, ext4, and btrfs to use them. This carries acks from all relevant filesystems. The VFS always uses coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot of metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g., backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. This introduces fine-grained timestamps that are used when they are actively queried. This uses the 31st bit of the ctime tv_nsec field to indicate that something has queried the inode for the mtime or ctime. When this flag is set, on the next mtime or ctime update, the kernel will fetch a fine-grained timestamp instead of the usual coarse-grained one. As POSIX generally mandates that when the mtime changes, the ctime must also change the kernel always stores normalized ctime values, so only the first 30 bits of the tv_nsec field are ever used. Filesytems can opt into this behavior by setting the FS_MGTIME flag in the fstype. Filesystems that don't set this flag will continue to use coarse-grained timestamps. Various preparatory changes, fixes and cleanups are included: - Fixup all relevant places where POSIX requires updating ctime together with mtime. This is a wide-range of places and all maintainers provided necessary Acks. - Add new accessors for inode->i_ctime directly and change all callers to rely on them. Plain accesses to inode->i_ctime are now gone and it is accordingly rename to inode->__i_ctime and commented as requiring accessors. - Extend generic_fillattr() to pass in a request mask mirroring in a sense the statx() uapi. This allows callers to pass in a request mask to only get a subset of attributes filled in. - Rework timestamp updates so it's possible to drop the @now parameter the update_time() inode operation and associated helpers. - Add inode_update_timestamps() and convert all filesystems to it removing a bunch of open-coding" * tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (107 commits) btrfs: convert to multigrain timestamps ext4: switch to multigrain timestamps xfs: switch to multigrain timestamps tmpfs: add support for multigrain timestamps fs: add infrastructure for multigrain timestamps fs: drop the timespec64 argument from update_time xfs: have xfs_vn_update_time gets its own timestamp fat: make fat_update_time get its own timestamp fat: remove i_version handling from fat_update_time ubifs: have ubifs_update_time use inode_update_timestamps btrfs: have it use inode_update_timestamps fs: drop the timespec64 arg from generic_update_time fs: pass the request_mask to generic_fillattr fs: remove silly warning from current_time gfs2: fix timestamp handling on quota inodes fs: rename i_ctime field to __i_ctime selinux: convert to ctime accessor functions security: convert to ctime accessor functions apparmor: convert to ctime accessor functions sunrpc: convert to ctime accessor functions ...

autofs: use wake_up() instead of wake_up_interruptible(()

2023-08-04T11:57:34+00:00

In autofs_wait_release() wake_up() is used to wake up processes waiting on a mount callback to complete which matches the wait_event_killable() in autofs_wait(). But in autofs_catatonic_mode() the wake_up_interruptible() was not also changed at the time autofs_wait_release() was changed. Signed-off-by: Ian Kent Message-Id: <169112719813.7590.4971499386839952992.stgit@donald.themaw.net> Signed-off-by: Christian Brauner

autofs: fix memory leak of waitqueues in autofs_catatonic_mode

2023-08-04T11:57:34+00:00

Syzkaller reports a memory leak: BUG: memory leak unreferenced object 0xffff88810b279e00 (size 96): comm "syz-executor399", pid 3631, jiffies 4294964921 (age 23.870s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 9e 27 0b 81 88 ff ff ..........'..... 08 9e 27 0b 81 88 ff ff 00 00 00 00 00 00 00 00 ..'............. backtrace: [] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046 [] kmalloc include/linux/slab.h:576 [inline] [] autofs_wait+0x3fa/0x9a0 fs/autofs/waitq.c:378 [] autofs_do_expire_multi+0xa7/0x3e0 fs/autofs/expire.c:593 [] autofs_expire_multi+0x53/0x80 fs/autofs/expire.c:619 [] autofs_root_ioctl_unlocked+0x322/0x3b0 fs/autofs/root.c:897 [] autofs_root_ioctl+0x25/0x30 fs/autofs/root.c:910 [] vfs_ioctl fs/ioctl.c:51 [inline] [] __do_sys_ioctl fs/ioctl.c:870 [inline] [] __se_sys_ioctl fs/ioctl.c:856 [inline] [] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:856 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd autofs_wait_queue structs should be freed if their wait_ctr becomes zero. Otherwise they will be lost. In this case an AUTOFS_IOC_EXPIRE_MULTI ioctl is done, then a new waitqueue struct is allocated in autofs_wait(), its initial wait_ctr equals 2. After that wait_event_killable() is interrupted (it returns -ERESTARTSYS), so that 'wq->name.name == NULL' condition may be not satisfied. Actually, this condition can be satisfied when autofs_wait_release() or autofs_catatonic_mode() is called and, what is also important, wait_ctr is decremented in those places. Upon the exit of autofs_wait(), wait_ctr is decremented to 1. Then the unmounting process begins: kill_sb calls autofs_catatonic_mode(), which should have freed the waitqueues, but it only decrements its usage counter to zero which is not a correct behaviour. edit:imk This description is of course not correct. The umount performed as a result of an expire is a umount of a mount that has been automounted, it's not the autofs mount itself. They happen independently, usually after everything mounted within the autofs file system has been expired away. If everything hasn't been expired away the automount daemon can still exit leaving mounts in place. But expires done in both cases will result in a notification that calls autofs_wait_release() with a result status. The problem case is the summary execution of of the automount daemon. In this case any waiting processes won't be woken up until either they are terminated or the mount is umounted. end edit: imk So in catatonic mode we should free waitqueues which counter becomes zero. edit: imk Initially I was concerned that the calling of autofs_wait_release() and autofs_catatonic_mode() was not mutually exclusive but that can't be the case (obviously) because the queue entry (or entries) is removed from the list when either of these two functions are called. Consequently the wait entry will be freed by only one of these functions or by the woken process in autofs_wait() depending on the order of the calls. end edit: imk Reported-by: syzbot+5e53f70e69ff0c0a1c0c@syzkaller.appspotmail.com Suggested-by: Takeshi Misawa Signed-off-by: Fedor Pchelkin Signed-off-by: Alexey Khoroshilov Signed-off-by: Ian Kent Cc: Matthew Wilcox Cc: Andrei Vagin Cc: autofs@vger.kernel.org Cc: linux-kernel@vger.kernel.org Message-Id: <169112719161.7590.6700123246297365841.stgit@donald.themaw.net> Signed-off-by: Christian Brauner

arch//configs/defconfig: Replace AUTOFS4_FS by AUTOFS_FS

2023-07-29T21:08:22+00:00

Commit a2225d931f75 ("autofs: remove left-over autofs4 stubs") promised the removal of the fs/autofs/Kconfig fragment for AUTOFS4_FS within a couple of releases, but five years later this still has not happened yet, and AUTOFS4_FS is still enabled in 63 defconfigs. Get rid of it mechanically: git grep -l CONFIG_AUTOFS4_FS -- '*defconfig' | xargs sed -i 's/AUTOFS4_FS/AUTOFS_FS/' Also just remove the AUTOFS4_FS config option stub. Anybody who hasn't regenerated their config file in the last five years will need to just get the new name right when they do. Signed-off-by: Sven Joachim Acked-by: Ian Kent Signed-off-by: Linus Torvalds

autofs: convert to ctime accessor functions

2023-07-13T08:28:04+00:00

In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Reviewed-by: Ian Kent Reviewed-by: Jan Kara Signed-off-by: Jeff Layton Message-Id: <20230705190309.579783-24-jlayton@kernel.org> Signed-off-by: Christian Brauner

autofs: set ctime as well when mtime changes on a dir

2023-06-15T07:22:24+00:00

When adding entries to a directory, POSIX generally requires that the ctime also be updated alongside the mtime. Signed-off-by: Jeff Layton Acked-by: Ian Kent Message-Id: <20230612104524.17058-4-jlayton@kernel.org> Signed-off-by: Christian Brauner

fs: port ->permission() to pass mnt_idmap

2023-01-19T08:24:28+00:00

Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft)

fs: port ->mkdir() to pass mnt_idmap

2023-01-19T08:24:26+00:00

fs: port ->symlink() to pass mnt_idmap

2023-01-19T08:24:25+00:00