kernel.git/fs/notify/fanotify, branch linux-6.9.y

fanotify: allow freeze when waiting response for permission events

2024-03-07T11:59:51Z

This is a long-standing issue that uninterruptible sleep in fanotify could make system hibernation fail if the usperspace server gets frozen before the process waiting for the response (as reported e.g. [1][2]). A few years ago, there was an attempt to switch to interruptible sleep while waiting [3], but that would lead to EINTR returns from open(2) and break userspace [4], so it's been changed to only killable [5]. And the core freezer logic had been rewritten [6][7] in v6.1, allowing freezing in uninterrupted sleep, so we can solve this problem now. [1] https://lore.kernel.org/lkml/1518774280-38090-1-git-send-email-t.vivek@samsung.com/ [2] https://lore.kernel.org/lkml/c1bb16b7-9eee-9cea-2c96-a512d8b3b9c7@nwra.com/ [3] https://lore.kernel.org/linux-fsdevel/20190213145443.26836-1-jack@suse.cz/ [4] https://lore.kernel.org/linux-fsdevel/d0031e3a-f050-0832-fa59-928a80ffd44b@nwra.com/ [5] https://lore.kernel.org/linux-fsdevel/20190221105558.GA20921@quack2.suse.cz/ [6] https://lore.kernel.org/lkml/20220822114649.055452969@infradead.org/ [7] https://lore.kernel.org/lkml/20230908-avoid-spurious-freezer-wakeups-v4-0-6155aa3dafae@quicinc.com/ Signed-off-by: Winston Wen Signed-off-by: Jan Kara Message-Id:

Merge tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

2024-01-11T01:44:36Z

Pull sysctl updates from Luis Chamberlain: "To help make the move of sysctls out of kernel/sysctl.c not incur a size penalty sysctl has been changed to allow us to not require the sentinel, the final empty element on the sysctl array. Joel Granados has been doing all this work. In the v6.6 kernel we got the major infrastructure changes required to support this. For v6.7 we had all arch/ and drivers/ modified to remove the sentinel. For v6.8-rc1 we get a few more updates for fs/ directory only. The kernel/ directory is left but we'll save that for v6.9-rc1 as those patches are still being reviewed. After that we then can expect also the removal of the no longer needed check for procname == NULL. Let us recap the purpose of this work: - this helps reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array - the extra 64-byte penalty is no longer inncurred now when we move sysctls out from kernel/sysctl.c to their own files Thomas Weißschuh also sent a few cleanups, for v6.9-rc1 we expect to see further work by Thomas Weißschuh with the constificatin of the struct ctl_table. Due to Joel Granados's work, and to help bring in new blood, I have suggested for him to become a maintainer and he's accepted. So for v6.9-rc1 I look forward to seeing him sent you a pull request for further sysctl changes. This also removes Iurii Zaikin as a maintainer as he has moved on to other projects and has had no time to help at all" * tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: sysctl: remove struct ctl_path sysctl: delete unused define SYSCTL_PERM_EMPTY_DIR coda: Remove the now superfluous sentinel elements from ctl_table array sysctl: Remove the now superfluous sentinel elements from ctl_table array fs: Remove the now superfluous sentinel elements from ctl_table array cachefiles: Remove the now superfluous sentinel element from ctl_table array sysclt: Clarify the results of selftest run sysctl: Add a selftest for handling empty dirs sysctl: Fix out of bounds access for empty sysctl registers MAINTAINERS: Add Joel Granados as co-maintainer for proc sysctl MAINTAINERS: remove Iurii Zaikin from proc sysctl

fs: Remove the now superfluous sentinel elements from ctl_table array

2023-12-28T12:57:57Z

This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel elements ctl_table struct. Special attention was placed in making sure that an empty directory for fs/verity was created when CONFIG_FS_VERITY_BUILTIN_SIGNATURES is not defined. In this case we use the register sysctl call that expects a size. Signed-off-by: Joel Granados Reviewed-by: Jan Kara Reviewed-by: "Darrick J. Wong" Acked-by: Christian Brauner Signed-off-by: Luis Chamberlain

fanotify: allow "weak" fsid when watching a single filesystem

2023-12-01T09:55:21Z

So far, fanotify returns -ENODEV or -EXDEV when trying to set a mark on a filesystem with a "weak" fsid, namely, zero fsid (e.g. fuse), or non-uniform fsid (e.g. btrfs non-root subvol). When group is watching inodes all from the same filesystem (or subvol), allow adding inode marks with "weak" fsid, because there is no ambiguity regarding which filesystem reports the event. The first mark added to a group determines if this group is single or multi filesystem, depending on the fsid at the path of the added mark. If the first mark added has a "strong" fsid, marks with "weak" fsid cannot be added and vice versa. If the first mark added has a "weak" fsid, following marks must have the same "weak" fsid and the same sb as the first mark. Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Message-Id: <20231130165619.3386452-3-amir73il@gmail.com>

fanotify: store fsid in mark instead of in connector

2023-12-01T09:55:21Z

Some filesystems like fuse and nfs have zero or non-unique fsid. We would like to avoid reporting ambiguous fsid in events, so we need to avoid marking objects with same fsid and different sb. To make this easier to enforce, store the fsid in the marks of the group instead of in the shared conenctor. Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Message-Id: <20231130165619.3386452-2-amir73il@gmail.com>

Merge tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2023-11-07T20:11:26Z

Pull vfs fanotify fsid updates from Christian Brauner: "This work is part of the plan to enable fanotify to serve as a drop-in replacement for inotify. While inotify is availabe on all filesystems, fanotify currently isn't. In order to support fanotify on all filesystems two things are needed: (1) all filesystems need to support AT_HANDLE_FID (2) all filesystems need to report a non-zero f_fsid This contains (1) and allows filesystems to encode non-decodable file handlers for fanotify without implementing any exportfs operations by encoding a file id of type FILEID_INO64_GEN from i_ino and i_generation. Filesystems that want to opt out of encoding non-decodable file ids for fanotify that don't support NFS export can do so by providing an empty export_operations struct. This also partially addresses (2) by generating f_fsid for simple filesystems as well as freevxfs. Remaining filesystems will be dealt with by separate patches. Finally, this contains the patch from the current exportfs maintainers which moves exportfs under vfs with Chuck, Jeff, and Amir as maintainers and vfs.git as tree" * tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: MAINTAINERS: create an entry for exportfs fs: fix build error with CONFIG_EXPORTFS=m or not defined freevxfs: derive f_fsid from bdev->bd_dev fs: report f_fsid from s_dev for "simple" filesystems exportfs: support encoding non-decodeable file handles by default exportfs: define FILEID_INO64_GEN* file handle types exportfs: make ->encode_fh() a mandatory method for NFS export exportfs: add helpers to check if filesystem can encode/decode file handles

Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-11-03T06:53:31Z

Pull non-MM updates from Andrew Morton: "As usual, lots of singleton and doubleton patches all over the tree and there's little I can say which isn't in the individual changelogs. The lengthier patch series are - 'kdump: use generic functions to simplify crashkernel reservation in arch', from Baoquan He. This is mainly cleanups and consolidation of the 'crashkernel=' kernel parameter handling - After much discussion, David Laight's 'minmax: Relax type checks in min() and max()' is here. Hopefully reduces some typecasting and the use of min_t() and max_t() - A group of patches from Oleg Nesterov which clean up and slightly fix our handling of reads from /proc/PID/task/... and which remove task_struct.thread_group" * tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits) scripts/gdb/vmalloc: disable on no-MMU scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n .mailmap: add address mapping for Tomeu Vizoso mailmap: update email address for Claudiu Beznea tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions .mailmap: map Benjamin Poirier's address scripts/gdb: add lx_current support for riscv ocfs2: fix a spelling typo in comment proc: test ProtectionKey in proc-empty-vm test proc: fix proc-empty-vm test with vsyscall fs/proc/base.c: remove unneeded semicolon do_io_accounting: use sig->stats_lock do_io_accounting: use __for_each_thread() ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error() ocfs2: fix a typo in a comment scripts/show_delta: add __main__ judgement before main code treewide: mark stuff as __ro_after_init fs: ocfs2: check status values proc: test /proc/${pid}/statm compiler.h: move __is_constexpr() to compiler.h ...

Merge tag 'fsnotify_for_v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2023-11-02T18:27:04Z

Pull fsnotify update from Jan Kara: "This time just one tiny cleanup for fsnotify" * tag 'fsnotify_for_v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fanotify: delete useless parenthesis in FANOTIFY_INLINE_FH macro

exportfs: add helpers to check if filesystem can encode/decode file handles

2023-10-24T15:57:45Z

The logic of whether filesystem can encode/decode file handles is open coded in many places. In preparation to changing the logic, move the open coded logic into inline helpers. Reviewed-by: Jan Kara Reviewed-by: Jeff Layton Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20231023180801.2953446-2-amir73il@gmail.com Signed-off-by: Christian Brauner

fanotify: limit reporting of event with non-decodeable file handles

2023-10-19T14:19:20Z

Commit a95aef69a740 ("fanotify: support reporting non-decodeable file handles") merged in v6.5-rc1, added the ability to use an fanotify group with FAN_REPORT_FID mode to watch filesystems that do not support nfs export, but do know how to encode non-decodeable file handles, with the newly introduced AT_HANDLE_FID flag. At the time that this commit was merged, there were no filesystems in-tree with those traits. Commit 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles"), merged in v6.6-rc1, added this trait to overlayfs, thus allowing fanotify watching of overlayfs with FAN_REPORT_FID mode. In retrospect, allowing an fanotify filesystem/mount mark on such filesystem in FAN_REPORT_FID mode will result in getting events with file handles, without the ability to resolve the filesystem objects from those file handles (i.e. no open_by_handle_at() support). For v6.6, the safer option would be to allow this mode for inode marks only, where the caller has the opportunity to use name_to_handle_at() at the time of setting the mark. In the future we can revise this decision. Fixes: a95aef69a740 ("fanotify: support reporting non-decodeable file handles") Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Message-Id: <20231018100000.2453965-2-amir73il@gmail.com>