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2024-01-12Merge tag 'pull-dcache' of ↵Linus Torvalds1-5/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull dcache updates from Al Viro: "Change of locking rules for __dentry_kill(), regularized refcounting rules in that area, assorted cleanups and removal of weird corner cases (e.g. now ->d_iput() on child is always called before the parent might hit __dentry_kill(), etc)" * tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) dcache: remove unnecessary NULL check in dget_dlock() kill DCACHE_MAY_FREE __d_unalias() doesn't use inode argument d_alloc_parallel(): in-lookup hash insertion doesn't need an RCU variant get rid of DCACHE_GENOCIDE d_genocide(): move the extern into fs/internal.h simple_fill_super(): don't bother with d_genocide() on failure nsfs: use d_make_root() d_alloc_pseudo(): move setting ->d_op there from the (sole) caller kill d_instantate_anon(), fold __d_instantiate_anon() into remaining caller retain_dentry(): introduce a trimmed-down lockless variant __dentry_kill(): new locking scheme d_prune_aliases(): use a shrink list switch select_collect{,2}() to use of to_shrink_list() to_shrink_list(): call only if refcount is 0 fold dentry_kill() into dput() don't try to cut corners in shrink_lock_dentry() fold the call of retain_dentry() into fast_dput() Call retain_dentry() with refcount 0 dentry_kill(): don't bother with retain_dentry() on slow path ...
2023-11-25dentry: switch the lists of children to hlistAl Viro1-5/+2
Saves a pointer per struct dentry and actually makes the things less clumsy. Cleaned the d_walk() and dcache_readdir() a bit by use of hlist_for_... iterators. A couple of new helpers - d_first_child() and d_next_sibling(), to make the expressions less awful. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-11-20autofs: add: new_inode check in autofs_fill_super()Ian Kent1-35/+21
Add missing NULL check of root_inode in autofs_fill_super(). While we are at it simplify the logic by taking advantage of the VFS cleanup procedures and get rid of the goto error handling, as suggested by Al Viro. Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/20231119225319.331156-1-raven@themaw.net Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Bill O'Donnell <billodo@redhat.com> Reported-by: <syzbot+662f87a8ef490f45fa64@syzkaller.appspotmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-30Merge tag 'vfs-6.7.ctime' of ↵Linus Torvalds2-4/+4
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs inode time accessor updates from Christian Brauner: "This finishes the conversion of all inode time fields to accessor functions as discussed on list. Changing timestamps manually as we used to do before is error prone. Using accessors function makes this robust. It does not contain the switch of the time fields to discrete 64 bit integers to replace struct timespec and free up space in struct inode. But after this, the switch can be trivially made and the patch should only affect the vfs if we decide to do it" * tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (86 commits) fs: rename inode i_atime and i_mtime fields security: convert to new timestamp accessors selinux: convert to new timestamp accessors apparmor: convert to new timestamp accessors sunrpc: convert to new timestamp accessors mm: convert to new timestamp accessors bpf: convert to new timestamp accessors ipc: convert to new timestamp accessors linux: convert to new timestamp accessors zonefs: convert to new timestamp accessors xfs: convert to new timestamp accessors vboxsf: convert to new timestamp accessors ufs: convert to new timestamp accessors udf: convert to new timestamp accessors ubifs: convert to new timestamp accessors tracefs: convert to new timestamp accessors sysv: convert to new timestamp accessors squashfs: convert to new timestamp accessors server: convert to new timestamp accessors client: convert to new timestamp accessors ...
2023-10-24autofs: fix add autofs_parse_fd()Ian Kent2-4/+11
We are seeing systemd hang on its autofs direct mount at /proc/sys/fs/binfmt_misc. Historically this was due to a mismatch in the communication structure size between a 64 bit kernel and a 32 bit user space and was fixed by making the pipe communication record oriented. During autofs v5 development I decided to stay with the existing usage instead of changing to a packed structure for autofs <=> user space communications which turned out to be a mistake on my part. Problems arose and they were fixed by allowing for the 64 bit to 32 bit size difference in the automount(8) code. Along the way systemd started to use autofs and eventually encountered this problem too. systemd refused to compensate for the length difference insisting it be fixed in the kernel. Fortunately Linus implemented the packetized pipe which resolved the problem in a straight forward and simple way. In the autofs mount api conversion series I inadvertatly dropped the packet pipe flag settings when adding the autofs_parse_fd() function. This patch fixes that omission. Fixes: 546694b8f658 ("autofs: add autofs_parse_fd()") Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/20231023093359.64265-1-raven@themaw.net Tested-by: Anders Roxell <anders.roxell@linaro.org> Cc: Bill O'Donnell <bodonnel@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-18autofs: convert to new timestamp accessorsJeff Layton2-4/+4
Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185347.80880-17-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: fix protocol sub version settingIan Kent1-1/+11
There were a number of updates to protocol version 4, take account of that when setting the super block info sub version field. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-9-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: convert autofs to use the new mount apiIan Kent3-124/+155
Convert the autofs filesystem to use the mount API. The conversion patch was originally written by David Howells. I have taken that patch and broken it into several patches in an effort to make the change easier to review. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-8-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: validate protocol versionIan Kent1-15/+23
Move the protocol parameter validation into a seperate function. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-7-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: refactor parse_options()Ian Kent1-64/+72
Seperate out parts of parse_options() that will match better the individual option processing used in the mount API to further simplify the upcoming conversion. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-6-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: reformat 0pt enum declarationIan Kent1-3/+14
The enum of options is only reformated in the patch to convert autofs to use the mount API so do that now to simplify the conversion patch. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-5-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: refactor super block info initIan Kent1-25/+28
Move the allocation and initialisation of the super block info struct to its own function. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-4-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: add autofs_parse_fd()Ian Kent1-17/+31
Factor out the fd mount option handling. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-3-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-22autofs: refactor autofs_prepare_pipe()Ian Kent1-1/+9
Refactor autofs_prepare_pipe() by seperating out a check function to be used later. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Message-Id: <20230922041215.13675-2-raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-28Merge tag 'v6.6-vfs.autofs' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs 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
2023-08-28Merge tag 'v6.6-vfs.ctime' of ↵Linus Torvalds2-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs 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 ...
2023-08-04autofs: use wake_up() instead of wake_up_interruptible(()Ian Kent1-1/+1
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 <raven@themaw.net> Message-Id: <169112719813.7590.4971499386839952992.stgit@donald.themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-04autofs: fix memory leak of waitqueues in autofs_catatonic_modeFedor Pchelkin1-1/+2
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: [<ffffffff814cfc90>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046 [<ffffffff81bb75ca>] kmalloc include/linux/slab.h:576 [inline] [<ffffffff81bb75ca>] autofs_wait+0x3fa/0x9a0 fs/autofs/waitq.c:378 [<ffffffff81bb88a7>] autofs_do_expire_multi+0xa7/0x3e0 fs/autofs/expire.c:593 [<ffffffff81bb8c33>] autofs_expire_multi+0x53/0x80 fs/autofs/expire.c:619 [<ffffffff81bb6972>] autofs_root_ioctl_unlocked+0x322/0x3b0 fs/autofs/root.c:897 [<ffffffff81bb6a95>] autofs_root_ioctl+0x25/0x30 fs/autofs/root.c:910 [<ffffffff81602a9c>] vfs_ioctl fs/ioctl.c:51 [inline] [<ffffffff81602a9c>] __do_sys_ioctl fs/ioctl.c:870 [inline] [<ffffffff81602a9c>] __se_sys_ioctl fs/ioctl.c:856 [inline] [<ffffffff81602a9c>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:856 [<ffffffff84608225>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff84608225>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84800087>] 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 <jeliantsurux@gmail.com> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Ian Kent <raven@themaw.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Andrei Vagin <avagin@gmail.com> 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 <brauner@kernel.org>
2023-07-30arch/*/configs/*defconfig: Replace AUTOFS4_FS by AUTOFS_FSSven Joachim1-12/+0
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 <svenjoac@gmx.de> Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-13autofs: convert to ctime accessor functionsJeff Layton2-4/+4
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 <raven@themaw.net> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jeff Layton <jlayton@kernel.org> Message-Id: <20230705190309.579783-24-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-15autofs: set ctime as well when mtime changes on a dirJeff Layton1-3/+3
When adding entries to a directory, POSIX generally requires that the ctime also be updated alongside the mtime. Signed-off-by: Jeff Layton <jlayton@kernel.org> Acked-by: Ian Kent <raven@themaw.net> Message-Id: <20230612104524.17058-4-jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-01-19fs: port ->permission() to pass mnt_idmapChristian Brauner1-3/+3
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 <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->mkdir() to pass mnt_idmapChristian Brauner1-2/+2
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 <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19fs: port ->symlink() to pass mnt_idmapChristian Brauner1-2/+2
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 <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-07-18autofs: remove unused ino field inodeIan Kent1-2/+0
Remove the unused inode field of the autofs dentry info structure. Link: https://lkml.kernel.org/r/165724460393.30914.6511330213821246793.stgit@donald.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18autofs: add comment about autofs_mountpoint_changed()Ian Kent1-3/+20
The function autofs_mountpoint_changed() is unusual, add a comment about two cases for which it is needed. Link: https://lkml.kernel.org/r/165724459804.30914.10974834416046555127.stgit@donald.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18autofs: use dentry info count instead of simple_empty()Ian Kent3-11/+14
The dentry info. field count is used to check if a dentry is in use during expire. But, to be used for this the count field must account for the presence of child dentries in a directory dentry. Therefore it can also be used to check for an empty directory dentry which can be done without having to to take an additional lock or account for the presence of a readdir cursor dentry as is done by simple_empty(). Link: https://lkml.kernel.org/r/165724459238.30914.1504611159945950108.stgit@donald.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18autofs: make dentry info count consistentIan Kent2-4/+1
If an autofs dentry is a mount root directory there's no ->mkdir() call to set its count to one. To make the dentry info count consistent for all autofs dentries set count to one when the dentry info struct is allocated. Link: https://lkml.kernel.org/r/165724458671.30914.2902424437132835325.stgit@donald.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18autofs: use inode permission method for write accessIan Kent1-41/+22
Patch series "autofs: misc patches". This series contains several patches that resulted mostly from comments made by Al Viro (quite a long time ago now). This patch (of 5): Eliminate some code duplication from mkdir/rmdir/symlink/unlink methods by using the inode operation .permission(). Link: https://lkml.kernel.org/r/165724445154.30914.10970894936827635879.stgit@donald.themaw.net Link: https://lkml.kernel.org/r/165724458096.30914.13499431569758625806.stgit@donald.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2021-10-21autofs: fix wait name hash calculation in autofs_wait()Ian Kent1-1/+1
There's a mistake in commit 2be7828c9fefc ("get rid of autofs_getpath()") that affects kernels from v5.13.0, basically missed because of me not fully testing the change for Al. The problem is that the hash calculation for the wait name qstr hasn't been updated to account for the change to use dentry_path_raw(). This prevents the correct matching an existing wait resulting in multiple notifications being sent to the daemon for the same mount which must not occur. The problem wasn't discovered earlier because it only occurs when multiple processes trigger a request for the same mount concurrently so it only shows up in more aggressive testing. Fixes: 2be7828c9fefc ("get rid of autofs_getpath()") Cc: stable@vger.kernel.org Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-03-24autofs: should_expire() argument is guaranteed to be positiveAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-03-21get rid of autofs_getpath()Al Viro2-56/+17
allow wq->name.name to point not at the beginning of the object containing the string, with wq->offset telling how far into it we are. Then we can bloody well just use dentry_path_raw() instead of autofs_getpath() - the only real difference is that dentry_path_raw() puts the result into the end of buffer and returns where it starts. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-01-24fs: make helpers idmap mount awareChristian Brauner1-7/+10
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-12-10file: Replace ksys_close with close_fdEric W. Biederman1-2/+3
Now that ksys_close is exactly identical to close_fd replace the one caller of ksys_close with close_fd. [1] https://lkml.kernel.org/r/20200818112020.GA17080@infradead.org Suggested-by: Christoph Hellwig <hch@infradead.org> Link: https://lkml.kernel.org/r/20201120231441.29911-22-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-10-16autofs: harden ioctl tableMatthew Wilcox1-2/+6
The table of ioctl functions should be marked const in order to put them in read-only memory, and we should use array_index_nospec() to avoid speculation disclosing the contents of kernel memory to userspace. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Ian Kent <raven@themaw.net> Link: https://lkml.kernel.org/r/20200818122203.GO17456@casper.infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-30autofs: use __kernel_write() for the autofs pipe writingLinus Torvalds1-1/+1
autofs got broken in some configurations by commit 13c164b1a186 ("autofs: switch to kernel_write") because there is now an extra LSM permission check done by security_file_permission() in rw_verify_area(). autofs is one if the few places that really does want the much more limited __kernel_write(), because the write is an internal kernel one that shouldn't do any user permission checks (it also doesn't need the file_start_write/file_end_write logic, since it's just a pipe). There are a couple of other cases like that - accounting, core dumping, and splice - but autofs stands out because it can be built as a module. As a result, we need to export this internal __kernel_write() function again. We really don't want any other module to use this, but we don't have a "EXPORT_SYMBOL_FOR_AUTOFS_ONLY()". But we can mark it GPL-only to at least approximate that "internal use only" for licensing. While in this area, make autofs pass in NULL for the file position pointer, since it's always a pipe, and we now use a NULL file pointer for streaming file descriptors (see file_ppos() and commit 438ab720c675: "vfs: pass ppos=NULL to .read()/.write() of FMODE_STREAM files") This effectively reverts commits 9db977522449 ("fs: unexport __kernel_write") and 13c164b1a186 ("autofs: switch to kernel_write"). Fixes: 13c164b1a186 ("autofs: switch to kernel_write") Reported-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-15fs: autofs: delete repeated words in commentsRandy Dunlap1-2/+2
Drop duplicated words {the, at} in comments. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Ian Kent <raven@themaw.net> Link: http://lkml.kernel.org/r/20200811021817.24982-1-rdunlap@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-08autofs: switch to kernel_writeChristoph Hellwig1-1/+1
While pipes don't really need sb_writers projection, __kernel_write is an interface better kept private, and the additional rw_verify_area does not hurt here. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ian Kent <raven@themaw.net>
2020-03-14LOOKUP_MOUNTPOINT: fold path_mountpointat() into path_lookupat()Al Viro1-3/+3
New LOOKUP flag, telling path_lookupat() to act as path_mountpointat(). IOW, traverse mounts at the final point and skip revalidation of the location where it ends up. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-06Merge branch 'next.autofs' of ↵Linus Torvalds3-29/+18
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull autofs updates from Al Viro: "autofs misuses checks for ->d_subdirs emptiness; the cursors are in the same lists, resulting in false negatives. It's not needed anyway, since autofs maintains counter in struct autofs_info, containing 0 for removed ones, 1 for live symlinks and 1 + number of children for live directories, which is precisely what we need for those checks. This series switches to use of that counter and untangles the crap around its uses (it needs not be atomic and there's a bunch of completely pointless "defensive" checks). This fell out of dcache_readdir work; the main point is to get rid of ->d_subdirs abuses in there. I've more followup cleanups, but I hadn't run those by Ian yet, so they can go next cycle" * 'next.autofs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: autofs: don't bother with atomics for ino->count autofs_dir_rmdir(): check ino->count for deciding whether it's empty... autofs: get rid of pointless checks around ->count handling autofs_clear_leaf_automount_flags(): use ino->count instead of ->d_subdirs
2019-10-25autofs: fix a leak in autofs_expire_indirect()Al Viro1-2/+3
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>
2019-09-18autofs: don't bother with atomics for ino->countAl Viro3-14/+14
All writers are serialized on inode->i_rwsem. So are the readers outside of expire.c. And the readers in expire.c are in the code that really doesn't care about narrow races - it's looking for expiry candidates and its callers have to cope with the possibility of a good candidate becoming busy right under them. No point bothering with atomic operations - just use int and mark the non-serialized readers with READ_ONCE(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-18autofs_dir_rmdir(): check ino->count for deciding whether it's empty...Al Viro1-4/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-18autofs: get rid of pointless checks around ->count handlingAl Viro1-14/+8
* IS_ROOT can't be true for unlink or rmdir victim * any positive autofs dentry has non-NULL autofs_dentry_ino() * autofs symlink can't have ->count other than 1 * autofs empty directory can't have ->count other than 1 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-18autofs_clear_leaf_automount_flags(): use ino->count instead of ->d_subdirsAl Viro1-5/+1
We want to find out if the parent will become empty after we remove the victim of rmdir(). Checking if the victim is the only element of parent's ->d_subdirs is completely wrong - e.g. opening the parent will end up with a cursor added to its ->d_parent and fooling the check. We do maintain ino->count - 0 for anything removed, 1 + number of children for anything live. Which gives us precisely what we need for that check... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-27autofs_lookup(): hold ->d_lock over playing with ->d_flagsAl Viro1-6/+7
... as well as setting ->d_fsdata, etc. Make all of that atomic. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-27get rid of autofs_info->active_countAl Viro2-28/+6
autofs_add_active() is always called only once (and on a dentry with freshly allocated ino, at that). autofs_del_active() is never called more than once. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-25autofs: simplify get_next_positive_...(), get rid of trylocksAl Viro1-71/+32
* new helper: positive_after(parent, child); parent->d_lock is held by caller, grabs and returns the first thing after child in the list of children that has simple_positive() true. NULL if nothing's found; NULL child == search the entire list. * get_next_positive_subdir() loses the redundant check for d_count and switches to use of that helper. BTW, dput(NULL) is a no-op for a good reason... * get_next_positive_dentry() switched to the same helper. Logics: look for positive child in prev; if not found, look for the positive child of prev's parent following prev, etc. That way we are guaranteed that we are only moving rootwards through the ancestors of prev, which is pinned and thus not going anywhere. Since ->d_parent on autofs never changes, the same goes for the entire chain of ancestors and we don't need overlapping ->d_lock on them. Which avoids the trylock loops, in addition to simplifying the logics in there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 83Thomas Gleixner8-32/+8
Based on 1 normalized pattern(s): this file is part of the linux kernel and is made available under the terms of the gnu general public license version 2 or at your option any later version incorporated herein by reference extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 18 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520075211.321157221@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner2-0/+2
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>