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2023-10-30Merge tag 'vfs-6.7.ctime' of ↵Linus Torvalds193-907/+1046
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 ...
2023-10-30Merge tag 'vfs-6.7.xattr' of ↵Linus Torvalds53-66/+66
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs xattr updates from Christian Brauner: "The 's_xattr' field of 'struct super_block' currently requires a mutable table of 'struct xattr_handler' entries (although each handler itself is const). However, no code in vfs actually modifies the tables. This changes the type of 's_xattr' to allow const tables, and modifies existing file systems to move their tables to .rodata. This is desirable because these tables contain entries with function pointers in them; moving them to .rodata makes it considerably less likely to be modified accidentally or maliciously at runtime" * tag 'vfs-6.7.xattr' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (30 commits) const_structs.checkpatch: add xattr_handler net: move sockfs_xattr_handlers to .rodata shmem: move shmem_xattr_handlers to .rodata overlayfs: move xattr tables to .rodata xfs: move xfs_xattr_handlers to .rodata ubifs: move ubifs_xattr_handlers to .rodata squashfs: move squashfs_xattr_handlers to .rodata smb: move cifs_xattr_handlers to .rodata reiserfs: move reiserfs_xattr_handlers to .rodata orangefs: move orangefs_xattr_handlers to .rodata ocfs2: move ocfs2_xattr_handlers and ocfs2_xattr_handler_map to .rodata ntfs3: move ntfs_xattr_handlers to .rodata nfs: move nfs4_xattr_handlers to .rodata kernfs: move kernfs_xattr_handlers to .rodata jfs: move jfs_xattr_handlers to .rodata jffs2: move jffs2_xattr_handlers to .rodata hfsplus: move hfsplus_xattr_handlers to .rodata hfs: move hfs_xattr_handlers to .rodata gfs2: move gfs2_xattr_handlers_max to .rodata fuse: move fuse_xattr_handlers to .rodata ...
2023-10-30Merge tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfsLinus Torvalds20-174/+358
Pull misc vfs updates from Christian Brauner: "This contains the usual miscellaneous features, cleanups, and fixes for vfs and individual fses. Features: - Rename and export helpers that get write access to a mount. They are used in overlayfs to get write access to the upper mount. - Print the pretty name of the root device on boot failure. This helps in scenarios where we would usually only print "unknown-block(1,2)". - Add an internal SB_I_NOUMASK flag. This is another part in the endless POSIX ACL saga in a way. When POSIX ACLs are enabled via SB_POSIXACL the vfs cannot strip the umask because if the relevant inode has POSIX ACLs set it might take the umask from there. But if the inode doesn't have any POSIX ACLs set then we apply the umask in the filesytem itself. So we end up with: (1) no SB_POSIXACL -> strip umask in vfs (2) SB_POSIXACL -> strip umask in filesystem The umask semantics associated with SB_POSIXACL allowed filesystems that don't even support POSIX ACLs at all to raise SB_POSIXACL purely to avoid umask stripping. That specifically means NFS v4 and Overlayfs. NFS v4 does it because it delegates this to the server and Overlayfs because it needs to delegate umask stripping to the upper filesystem, i.e., the filesystem used as the writable layer. This went so far that SB_POSIXACL is raised eve on kernels that don't even have POSIX ACL support at all. Stop this blatant abuse and add SB_I_NOUMASK which is an internal superblock flag that filesystems can raise to opt out of umask handling. That should really only be the two mentioned above. It's not that we want any filesystems to do this. Ideally we have all umask handling always in the vfs. - Make overlayfs use SB_I_NOUMASK too. - Now that we have SB_I_NOUMASK, stop checking for SB_POSIXACL in IS_POSIXACL() if the kernel doesn't have support for it. This is a very old patch but it's only possible to do this now with the wider cleanup that was done. - Follow-up work on fake path handling from last cycle. Citing mostly from Amir: When overlayfs was first merged, overlayfs files of regular files and directories, the ones that are installed in file table, had a "fake" path, namely, f_path is the overlayfs path and f_inode is the "real" inode on the underlying filesystem. In v6.5, we took another small step by introducing of the backing_file container and the file_real_path() helper. This change allowed vfs and filesystem code to get the "real" path of an overlayfs backing file. With this change, we were able to make fsnotify work correctly and report events on the "real" filesystem objects that were accessed via overlayfs. This method works fine, but it still leaves the vfs vulnerable to new code that is not aware of files with fake path. A recent example is commit db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version"). This commit uses direct referencing to f_path in IMA code that otherwise uses file_inode() and file_dentry() to reference the filesystem objects that it is measuring. This contains work to switch things around: instead of having filesystem code opt-in to get the "real" path, have generic code opt-in for the "fake" path in the few places that it is needed. Is it far more likely that new filesystems code that does not use the file_dentry() and file_real_path() helpers will end up causing crashes or averting LSM/audit rules if we keep the "fake" path exposed by default. This change already makes file_dentry() moot, but for now we did not change this helper just added a WARN_ON() in ovl_d_real() to catch if we have made any wrong assumptions. After the dust settles on this change, we can make file_dentry() a plain accessor and we can drop the inode argument to ->d_real(). - Switch struct file to SLAB_TYPESAFE_BY_RCU. This looks like a small change but it really isn't and I would like to see everyone on their tippie toes for any possible bugs from this work. Essentially we've been doing most of what SLAB_TYPESAFE_BY_RCU for files since a very long time because of the nasty interactions between the SCM_RIGHTS file descriptor garbage collection. So extending it makes a lot of sense but it is a subtle change. There are almost no places that fiddle with file rcu semantics directly and the ones that did mess around with struct file internal under rcu have been made to stop doing that because it really was always dodgy. I forgot to put in the link tag for this change and the discussion in the commit so adding it into the merge message: https://lore.kernel.org/r/20230926162228.68666-1-mjguzik@gmail.com Cleanups: - Various smaller pipe cleanups including the removal of a spin lock that was only used to protect against writes without pipe_lock() from O_NOTIFICATION_PIPE aka watch queues. As that was never implemented remove the additional locking from pipe_write(). - Annotate struct watch_filter with the new __counted_by attribute. - Clarify do_unlinkat() cleanup so that it doesn't look like an extra iput() is done that would cause issues. - Simplify file cleanup when the file has never been opened. - Use module helper instead of open-coding it. - Predict error unlikely for stale retry. - Use WRITE_ONCE() for mount expiry field instead of just commenting that one hopes the compiler doesn't get smart. Fixes: - Fix readahead on block devices. - Fix writeback when layztime is enabled and inodes whose timestamp is the only thing that changed reside on wb->b_dirty_time. This caused excessively large zombie memory cgroup when lazytime was enabled as such inodes weren't handled fast enough. - Convert BUG_ON() to WARN_ON_ONCE() in open_last_lookups()" * tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (26 commits) file, i915: fix file reference for mmap_singleton() vfs: Convert BUG_ON to WARN_ON_ONCE in open_last_lookups writeback, cgroup: switch inodes with dirty timestamps to release dying cgwbs chardev: Simplify usage of try_module_get() ovl: rely on SB_I_NOUMASK fs: fix umask on NFS with CONFIG_FS_POSIX_ACL=n fs: store real path instead of fake path in backing file f_path fs: create helper file_user_path() for user displayed mapped file path fs: get mnt_writers count for an open backing file's real path vfs: stop counting on gcc not messing with mnt_expiry_mark if not asked vfs: predict the error in retry_estale as unlikely backing file: free directly vfs: fix readahead(2) on block devices io_uring: use files_lookup_fd_locked() file: convert to SLAB_TYPESAFE_BY_RCU vfs: shave work on failed file open fs: simplify misleading code to remove ambiguity regarding ihold()/iput() watch_queue: Annotate struct watch_filter with __counted_by fs/pipe: use spinlock in pipe_read() only if there is a watch_queue fs/pipe: remove unnecessary spinlock from pipe_write() ...
2023-10-30Merge tag 'vfs-6.7.autofs' of ↵Linus Torvalds4-182/+283
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull autofs mount api updates from Christian Brauner: "This ports autofs to the new mount api. The patchset has existed for quite a while but never made it upstream. Ian picked it back up. This also fixes a bug where fs_param_is_fd() was passed a garbage param->dirfd but it expected it to be set to the fd that was used to set param->file otherwise result->uint_32 contains nonsense. So make sure it's set. One less filesystem using the old mount api. We're getting there, albeit rather slow. The last remaining major filesystem that hasn't converted is btrfs. Patches exist - I even wrote them - but so far they haven't made it upstream" * tag 'vfs-6.7.autofs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: autofs: fix add autofs_parse_fd() fsconfig: ensure that dirfd is set to aux autofs: fix protocol sub version setting autofs: convert autofs to use the new mount api autofs: validate protocol version autofs: refactor parse_options() autofs: reformat 0pt enum declaration autofs: refactor super block info init autofs: add autofs_parse_fd() autofs: refactor autofs_prepare_pipe()
2023-10-30Merge tag 'vfs-6.7.super' of ↵Linus Torvalds27-306/+345
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs superblock updates from Christian Brauner: "This contains the work to make block device opening functions return a struct bdev_handle instead of just a struct block_device. The same struct bdev_handle is then also passed to block device closing functions. This allows us to propagate context from opening to closing a block device without having to modify all users everytime. Sidenote, in the future we might even want to try and have block device opening functions return a struct file directly but that's a series on top of this. These are further preparatory changes to be able to count writable opens and blocking writes to mounted block devices. That's a separate piece of work for next cycle and for that we absolutely need the changes to btrfs that have been quietly dropped somehow. Originally the series contained a patch that removed the old blkdev_*() helpers. But since this would've caused needles churn in -next for bcachefs we ended up delaying it. The second piece of work addresses one of the major annoyances about the work last cycle, namely that we required dropping s_umount whenever we used the superblock and fs_holder_ops for a block device. The reason for that requirement had been that in some codepaths s_umount could've been taken under disk->open_mutex (that's always been the case, at least theoretically). For example, on surprise block device removal or media change. And opening and closing block devices required grabbing disk->open_mutex as well. So we did the work and went through the block layer and fixed all those places so that s_umount is never taken under disk->open_mutex. This means no more brittle games where we yield and reacquire s_umount during block device opening and closing and no more requirements where block devices need to be closed. Filesystems don't need to care about this. There's a bunch of other follow-up work such as moving block device freezing and thawing to holder operations which makes it work for all block devices and not just the main block device just as we did for surprise removal. But that is for next cycle. Tested with fstests for all major fses, blktests, LTP" * tag 'vfs-6.7.super' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (37 commits) porting: update locking requirements fs: assert that open_mutex isn't held over holder ops block: assert that we're not holding open_mutex over blk_report_disk_dead block: move bdev_mark_dead out of disk_check_media_change block: WARN_ON_ONCE() when we remove active partitions block: simplify bdev_del_partition() fs: Avoid grabbing sb->s_umount under bdev->bd_holder_lock jfs: fix log->bdev_handle null ptr deref in lbmStartIO bcache: Fixup error handling in register_cache() xfs: Convert to bdev_open_by_path() reiserfs: Convert to bdev_open_by_dev/path() ocfs2: Convert to use bdev_open_by_dev() nfs/blocklayout: Convert to use bdev_open_by_dev/path() jfs: Convert to bdev_open_by_dev() f2fs: Convert to bdev_open_by_dev/path() ext4: Convert to bdev_open_by_dev() erofs: Convert to use bdev_open_by_path() btrfs: Convert to bdev_open_by_path() fs: Convert to bdev_open_by_dev() mm/swap: Convert to use bdev_open_by_dev() ...
2023-10-28fs: assert that open_mutex isn't held over holder opsChristian Brauner1-0/+1
With recent block level changes we should never be in a situation where we hold disk->open_mutex when calling into these helpers. So assert that in the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20231017184823.1383356-6-hch@lst.de Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28fs: Avoid grabbing sb->s_umount under bdev->bd_holder_lockJan Kara1-18/+32
The implementation of bdev holder operations such as fs_bdev_mark_dead() and fs_bdev_sync() grab sb->s_umount semaphore under bdev->bd_holder_lock. This is problematic because it leads to disk->open_mutex -> sb->s_umount lock ordering which is counterintuitive (usually we grab higher level (e.g. filesystem) locks first and lower level (e.g. block layer) locks later) and indeed makes lockdep complain about possible locking cycles whenever we open a block device while holding sb->s_umount semaphore. Implement a function bdev_super_lock_shared() which safely transitions from holding bdev->bd_holder_lock to holding sb->s_umount on alive superblock without introducing the problematic lock dependency. We use this function fs_bdev_sync() and fs_bdev_mark_dead(). Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20231018152924.3858-1-jack@suse.cz Link: https://lore.kernel.org/r/20231017184823.1383356-1-hch@lst.de Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28jfs: fix log->bdev_handle null ptr deref in lbmStartIOLizhi Xu1-1/+5
When sbi->flag is JFS_NOINTEGRITY in lmLogOpen(), log->bdev_handle can't be inited, so it value will be NULL. Therefore, add the "log ->no_integrity=1" judgment in lbmStartIO() to avoid such problems. Reported-and-tested-by: syzbot+23bc20037854bb335d59@syzkaller.appspotmail.com Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Link: https://lore.kernel.org/r/20231009094557.1398920-1-lizhi.xu@windriver.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28xfs: Convert to bdev_open_by_path()Jan Kara3-31/+36
Convert xfs to use bdev_open_by_path() and pass the handle around. CC: "Darrick J. Wong" <djwong@kernel.org> CC: linux-xfs@vger.kernel.org Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-28-jack@suse.cz Acked-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28reiserfs: Convert to bdev_open_by_dev/path()Jan Kara3-36/+33
Convert reiserfs to use bdev_open_by_dev/path() and pass the handle around. CC: reiserfs-devel@vger.kernel.org Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-27-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28ocfs2: Convert to use bdev_open_by_dev()Jan Kara1-36/+45
Convert ocfs2 heartbeat code to use bdev_open_by_dev() and pass the handle around. CC: Joseph Qi <joseph.qi@linux.alibaba.com> CC: ocfs2-devel@oss.oracle.com Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-26-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28nfs/blocklayout: Convert to use bdev_open_by_dev/path()Jan Kara2-40/+38
Convert block device handling to use bdev_open_by_dev/path() and pass the handle around. CC: linux-nfs@vger.kernel.org CC: Trond Myklebust <trond.myklebust@hammerspace.com> CC: Anna Schumaker <anna@kernel.org> Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-25-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28jfs: Convert to bdev_open_by_dev()Jan Kara3-16/+18
Convert jfs to use bdev_open_by_dev() and pass the handle around. CC: Dave Kleikamp <shaggy@kernel.org> CC: jfs-discussion@lists.sourceforge.net Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-24-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28f2fs: Convert to bdev_open_by_dev/path()Jan Kara2-6/+8
Convert f2fs to use bdev_open_by_dev/path() and pass the handle around. CC: Jaegeuk Kim <jaegeuk@kernel.org> CC: Chao Yu <chao@kernel.org> CC: linux-f2fs-devel@lists.sourceforge.net Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-23-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28ext4: Convert to bdev_open_by_dev()Jan Kara3-30/+33
Convert ext4 to use bdev_open_by_dev() and pass the handle around. CC: linux-ext4@vger.kernel.org CC: Ted Tso <tytso@mit.edu> Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-22-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28erofs: Convert to use bdev_open_by_path()Jan Kara3-13/+13
Convert erofs to use bdev_open_by_path() and pass the handle around. CC: Gao Xiang <xiang@kernel.org> CC: Chao Yu <chao@kernel.org> CC: linux-erofs@lists.ozlabs.org Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-21-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28btrfs: Convert to bdev_open_by_path()Jan Kara4-72/+73
Convert btrfs to use bdev_open_by_path() and pass the handle around. We also drop the holder from struct btrfs_device as it is now not needed anymore. CC: David Sterba <dsterba@suse.com> CC: linux-btrfs@vger.kernel.org Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-20-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28fs: Convert to bdev_open_by_dev()Jan Kara3-8/+11
Convert mount code to use bdev_open_by_dev() and propagate the handle around to bdev_release(). Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-19-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-1/+1
Pull misc filesystem fixes from Al Viro: "Assorted fixes all over the place: literally nothing in common, could have been three separate pull requests. All are simple regression fixes, but not for anything from this cycle" * tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ceph_wait_on_conflict_unlink(): grab reference before dropping ->d_lock io_uring: kiocb_done() should *not* trust ->ki_pos if ->{read,write}_iter() failed sparc32: fix a braino in fault handling in csum_and_copy_..._user()
2023-10-28ceph_wait_on_conflict_unlink(): grab reference before dropping ->d_lockAl Viro1-1/+1
Use of dget() after we'd dropped ->d_lock is too late - dentry might be gone by that point. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-10-25file, i915: fix file reference for mmap_singleton()Christian Brauner1-0/+25
Today we got a report at [1] for rcu stalls on the i915 testsuite in [2] due to the conversion of files to SLAB_TYPSSAFE_BY_RCU. Afaict, get_file_rcu() goes into an infinite loop trying to carefully verify that i915->gem.mmap_singleton hasn't changed - see the splat below. So I stared at this code to figure out what it actually does. It seems that the i915->gem.mmap_singleton pointer itself never had rcu semantics. The i915->gem.mmap_singleton is replaced in file->f_op->release::singleton_release(): static int singleton_release(struct inode *inode, struct file *file) { struct drm_i915_private *i915 = file->private_data; cmpxchg(&i915->gem.mmap_singleton, file, NULL); drm_dev_put(&i915->drm); return 0; } The cmpxchg() is ordered against a concurrent update of i915->gem.mmap_singleton from mmap_singleton(). IOW, when mmap_singleton() fails to get a reference on i915->gem.mmap_singleton: While mmap_singleton() does rcu_read_lock(); file = get_file_rcu(&i915->gem.mmap_singleton); rcu_read_unlock(); it allocates a new file via anon_inode_getfile() and does smp_store_mb(i915->gem.mmap_singleton, file); So, then what happens in the case of this bug is that at some point fput() is called and drops the file->f_count to zero leaving the pointer in i915->gem.mmap_singleton in tact. Now, there might be delays until file->f_op->release::singleton_release() is called and i915->gem.mmap_singleton is set to NULL. Say concurrently another task hits mmap_singleton() and does: rcu_read_lock(); file = get_file_rcu(&i915->gem.mmap_singleton); rcu_read_unlock(); When get_file_rcu() fails to get a reference via atomic_inc_not_zero() it will try the reload from i915->gem.mmap_singleton expecting it to be NULL, assuming it has comparable semantics as we expect in __fget_files_rcu(). But it hasn't so it reloads the same pointer again, trying the same atomic_inc_not_zero() again and doing so until file->f_op->release::singleton_release() of the old file has been called. So, in contrast to __fget_files_rcu() here we want to not retry when atomic_inc_not_zero() has failed. We only want to retry in case we managed to get a reference but the pointer did change on reload. <3> [511.395679] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: <3> [511.395716] rcu: Tasks blocked on level-1 rcu_node (CPUs 0-9): P6238 <3> [511.395934] rcu: (detected by 16, t=65002 jiffies, g=123977, q=439 ncpus=20) <6> [511.395944] task:i915_selftest state:R running task stack:10568 pid:6238 tgid:6238 ppid:1001 flags:0x00004002 <6> [511.395962] Call Trace: <6> [511.395966] <TASK> <6> [511.395974] ? __schedule+0x3a8/0xd70 <6> [511.395995] ? asm_sysvec_apic_timer_interrupt+0x1a/0x20 <6> [511.396003] ? lockdep_hardirqs_on+0xc3/0x140 <6> [511.396013] ? asm_sysvec_apic_timer_interrupt+0x1a/0x20 <6> [511.396029] ? get_file_rcu+0x10/0x30 <6> [511.396039] ? get_file_rcu+0x10/0x30 <6> [511.396046] ? i915_gem_object_mmap+0xbc/0x450 [i915] <6> [511.396509] ? i915_gem_mmap+0x272/0x480 [i915] <6> [511.396903] ? mmap_region+0x253/0xb60 <6> [511.396925] ? do_mmap+0x334/0x5c0 <6> [511.396939] ? vm_mmap_pgoff+0x9f/0x1c0 <6> [511.396949] ? rcu_is_watching+0x11/0x50 <6> [511.396962] ? igt_mmap_offset+0xfc/0x110 [i915] <6> [511.397376] ? __igt_mmap+0xb3/0x570 [i915] <6> [511.397762] ? igt_mmap+0x11e/0x150 [i915] <6> [511.398139] ? __trace_bprintk+0x76/0x90 <6> [511.398156] ? __i915_subtests+0xbf/0x240 [i915] <6> [511.398586] ? __pfx___i915_live_setup+0x10/0x10 [i915] <6> [511.399001] ? __pfx___i915_live_teardown+0x10/0x10 [i915] <6> [511.399433] ? __run_selftests+0xbc/0x1a0 [i915] <6> [511.399875] ? i915_live_selftests+0x4b/0x90 [i915] <6> [511.400308] ? i915_pci_probe+0x106/0x200 [i915] <6> [511.400692] ? pci_device_probe+0x95/0x120 <6> [511.400704] ? really_probe+0x164/0x3c0 <6> [511.400715] ? __pfx___driver_attach+0x10/0x10 <6> [511.400722] ? __driver_probe_device+0x73/0x160 <6> [511.400731] ? driver_probe_device+0x19/0xa0 <6> [511.400741] ? __driver_attach+0xb6/0x180 <6> [511.400749] ? __pfx___driver_attach+0x10/0x10 <6> [511.400756] ? bus_for_each_dev+0x77/0xd0 <6> [511.400770] ? bus_add_driver+0x114/0x210 <6> [511.400781] ? driver_register+0x5b/0x110 <6> [511.400791] ? i915_init+0x23/0xc0 [i915] <6> [511.401153] ? __pfx_i915_init+0x10/0x10 [i915] <6> [511.401503] ? do_one_initcall+0x57/0x270 <6> [511.401515] ? rcu_is_watching+0x11/0x50 <6> [511.401521] ? kmalloc_trace+0xa3/0xb0 <6> [511.401532] ? do_init_module+0x5f/0x210 <6> [511.401544] ? load_module+0x1d00/0x1f60 <6> [511.401581] ? init_module_from_file+0x86/0xd0 <6> [511.401590] ? init_module_from_file+0x86/0xd0 <6> [511.401613] ? idempotent_init_module+0x17c/0x230 <6> [511.401639] ? __x64_sys_finit_module+0x56/0xb0 <6> [511.401650] ? do_syscall_64+0x3c/0x90 <6> [511.401659] ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8 <6> [511.401684] </TASK> Link: [1]: https://lore.kernel.org/intel-gfx/SJ1PR11MB6129CB39EED831784C331BAFB9DEA@SJ1PR11MB6129.namprd11.prod.outlook.com Link: [2]: https://intel-gfx-ci.01.org/tree/linux-next/next-20231013/bat-dg2-11/igt@i915_selftest@live@mman.html#dmesg-warnings10963 Cc: Jann Horn <jannh@google.com>, Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20231025-formfrage-watscheln-84526cd3bd7d@brauner Signed-off-by: Christian Brauner <brauner@kernel.org>
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>
2023-10-24vfs: Convert BUG_ON to WARN_ON_ONCE in open_last_lookupsBernd Schubert1-1/+2
The calling code actually handles -ECHILD, so this BUG_ON can be converted to WARN_ON_ONCE. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Link: https://lore.kernel.org/r/20231023184718.11143-1-bschubert@ddn.com Cc: Christian Brauner <brauner@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Amir Goldstein <amir73il@gmail.com> Cc: Dharmendra Singh <dsingh@ddn.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-24Merge tag 'pull-nfsd-fix' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull nfsd fix from Al Viro: "Catch from lock_rename() audit; nfsd_rename() checked that both directories belonged to the same filesystem, but only after having done lock_rename(). Trivial fix, tested and acked by nfs folks" * tag 'pull-nfsd-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: nfsd: lock_rename() needs both directories to live on the same fs
2023-10-23Merge tag 'for-6.6-rc7-tag' of ↵Linus Torvalds5-15/+33
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One more fix for a problem with snapshot of a newly created subvolume that can lead to inconsistent data under some circumstances. Kernel 6.5 added a performance optimization to skip transaction commit for subvolume creation but this could end up with newer data on disk but not linked to other structures. The fix itself is an added condition, the rest of the patch is a parameter added to several functions" * tag 'for-6.6-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix unwritten extent buffer after snapshotting a new subvolume
2023-10-23btrfs: fix unwritten extent buffer after snapshotting a new subvolumeFilipe Manana5-15/+33
When creating a snapshot of a subvolume that was created in the current transaction, we can end up not persisting a dirty extent buffer that is referenced by the snapshot, resulting in IO errors due to checksum failures when trying to read the extent buffer later from disk. A sequence of steps that leads to this is the following: 1) At ioctl.c:create_subvol() we allocate an extent buffer, with logical address 36007936, for the leaf/root of a new subvolume that has an ID of 291. We mark the extent buffer as dirty, and at this point the subvolume tree has a single node/leaf which is also its root (level 0); 2) We no longer commit the transaction used to create the subvolume at create_subvol(). We used to, but that was recently removed in commit 1b53e51a4a8f ("btrfs: don't commit transaction for every subvol create"); 3) The transaction used to create the subvolume has an ID of 33, so the extent buffer 36007936 has a generation of 33; 4) Several updates happen to subvolume 291 during transaction 33, several files created and its tree height changes from 0 to 1, so we end up with a new root at level 1 and the extent buffer 36007936 is now a leaf of that new root node, which is extent buffer 36048896. The commit root remains as 36007936, since we are still at transaction 33; 5) Creation of a snapshot of subvolume 291, with an ID of 292, starts at ioctl.c:create_snapshot(). This triggers a commit of transaction 33 and we end up at transaction.c:create_pending_snapshot(), in the critical section of a transaction commit. There we COW the root of subvolume 291, which is extent buffer 36048896. The COW operation returns extent buffer 36048896, since there's no need to COW because the extent buffer was created in this transaction and it was not written yet. The we call btrfs_copy_root() against the root node 36048896. During this operation we allocate a new extent buffer to turn into the root node of the snapshot, copy the contents of the root node 36048896 into this snapshot root extent buffer, set the owner to 292 (the ID of the snapshot), etc, and then we call btrfs_inc_ref(). This will create a delayed reference for each leaf pointed by the root node with a reference root of 292 - this includes a reference for the leaf 36007936. After that we set the bit BTRFS_ROOT_FORCE_COW in the root's state. Then we call btrfs_insert_dir_item(), to create the directory entry in in the tree of subvolume 291 that points to the snapshot. This ends up needing to modify leaf 36007936 to insert the respective directory items. Because the bit BTRFS_ROOT_FORCE_COW is set for the root's state, we need to COW the leaf. We end up at btrfs_force_cow_block() and then at update_ref_for_cow(). At update_ref_for_cow() we call btrfs_block_can_be_shared() which returns false, despite the fact the leaf 36007936 is shared - the subvolume's root and the snapshot's root point to that leaf. The reason that it incorrectly returns false is because the commit root of the subvolume is extent buffer 36007936 - it was the initial root of the subvolume when we created it. So btrfs_block_can_be_shared() which has the following logic: int btrfs_block_can_be_shared(struct btrfs_root *root, struct extent_buffer *buf) { if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && buf != root->node && buf != root->commit_root && (btrfs_header_generation(buf) <= btrfs_root_last_snapshot(&root->root_item) || btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) return 1; return 0; } Returns false (0) since 'buf' (extent buffer 36007936) matches the root's commit root. As a result, at update_ref_for_cow(), we don't check for the number of references for extent buffer 36007936, we just assume it's not shared and therefore that it has only 1 reference, so we set the local variable 'refs' to 1. Later on, in the final if-else statement at update_ref_for_cow(): static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *cow, int *last_ref) { (...) if (refs > 1) { (...) } else { (...) btrfs_clear_buffer_dirty(trans, buf); *last_ref = 1; } } So we mark the extent buffer 36007936 as not dirty, and as a result we don't write it to disk later in the transaction commit, despite the fact that the snapshot's root points to it. Attempting to access the leaf or dumping the tree for example shows that the extent buffer was not written: $ btrfs inspect-internal dump-tree -t 292 /dev/sdb btrfs-progs v6.2.2 file tree key (292 ROOT_ITEM 33) node 36110336 level 1 items 2 free space 119 generation 33 owner 292 node 36110336 flags 0x1(WRITTEN) backref revision 1 checksum stored a8103e3e checksum calced a8103e3e fs uuid 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79 chunk uuid e8c9c885-78f4-4d31-85fe-89e5f5fd4a07 key (256 INODE_ITEM 0) block 36007936 gen 33 key (257 EXTENT_DATA 0) block 36052992 gen 33 checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 total bytes 107374182400 bytes used 38572032 uuid 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79 The respective on disk region is full of zeroes as the device was trimmed at mkfs time. Obviously 'btrfs check' also detects and complains about this: $ btrfs check /dev/sdb Opening filesystem to check... Checking filesystem on /dev/sdb UUID: 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79 generation: 33 (33) [1/7] checking root items [2/7] checking extents checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 bad tree block 36007936, bytenr mismatch, want=36007936, have=0 owner ref check failed [36007936 4096] ERROR: errors found in extent allocation tree or chunk allocation [3/7] checking free space tree [4/7] checking fs roots checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29 bad tree block 36007936, bytenr mismatch, want=36007936, have=0 The following tree block(s) is corrupted in tree 292: tree block bytenr: 36110336, level: 1, node key: (256, 1, 0) root 292 root dir 256 not found ERROR: errors found in fs roots found 38572032 bytes used, error(s) found total csum bytes: 16048 total tree bytes: 1265664 total fs tree bytes: 1118208 total extent tree bytes: 65536 btree space waste bytes: 562598 file data blocks allocated: 65978368 referenced 36569088 Fix this by updating btrfs_block_can_be_shared() to consider that an extent buffer may be shared if it matches the commit root and if its generation matches the current transaction's generation. This can be reproduced with the following script: $ cat test.sh #!/bin/bash MNT=/mnt/sdi DEV=/dev/sdi # Use a filesystem with a 64K node size so that we have the same node # size on every machine regardless of its page size (on x86_64 default # node size is 16K due to the 4K page size, while on PPC it's 64K by # default). This way we can make sure we are able to create a btree for # the subvolume with a height of 2. mkfs.btrfs -f -n 64K $DEV mount $DEV $MNT btrfs subvolume create $MNT/subvol # Create a few empty files on the subvolume, this bumps its btree # height to 2 (root node at level 1 and 2 leaves). for ((i = 1; i <= 300; i++)); do echo -n > $MNT/subvol/file_$i done btrfs subvolume snapshot -r $MNT/subvol $MNT/subvol/snap umount $DEV btrfs check $DEV Running it on a 6.5 kernel (or any 6.6-rc kernel at the moment): $ ./test.sh Create subvolume '/mnt/sdi/subvol' Create a readonly snapshot of '/mnt/sdi/subvol' in '/mnt/sdi/subvol/snap' Opening filesystem to check... Checking filesystem on /dev/sdi UUID: bbdde2ff-7d02-45ca-8a73-3c36f23755a1 [1/7] checking root items [2/7] checking extents parent transid verify failed on 30539776 wanted 7 found 5 parent transid verify failed on 30539776 wanted 7 found 5 parent transid verify failed on 30539776 wanted 7 found 5 Ignoring transid failure owner ref check failed [30539776 65536] ERROR: errors found in extent allocation tree or chunk allocation [3/7] checking free space tree [4/7] checking fs roots parent transid verify failed on 30539776 wanted 7 found 5 Ignoring transid failure Wrong key of child node/leaf, wanted: (256, 1, 0), have: (2, 132, 0) Wrong generation of child node/leaf, wanted: 5, have: 7 root 257 root dir 256 not found ERROR: errors found in fs roots found 917504 bytes used, error(s) found total csum bytes: 0 total tree bytes: 851968 total fs tree bytes: 393216 total extent tree bytes: 65536 btree space waste bytes: 736550 file data blocks allocated: 0 referenced 0 A test case for fstests will follow soon. Fixes: 1b53e51a4a8f ("btrfs: don't commit transaction for every subvol create") CC: stable@vger.kernel.org # 6.5+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-21Merge tag 'iomap-6.6-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds1-3/+7
Pull iomap fix from Darrick Wong: - Fix a bug where a writev consisting of a bunch of sub-fsblock writes where the last buffer address is invalid could lead to an infinite loop * tag 'iomap-6.6-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: iomap: fix short copy in iomap_write_iter()
2023-10-21Merge tag 'nfs-for-6.6-4' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds5-21/+38
Pull NFS client fixes from Anna Schumaker: "Stable Fix: - Fix a pNFS hang in nfs4_evict_inode() Fixes: - Force update of suid/sgid bits after an NFS v4.2 ALLOCATE op - Fix a potential oops in nfs_inode_remove_request() - Check the validity of the layout pointer in ff_layout_mirror_prepare_stats() - Fix incorrectly marking the pNFS MDS with USE_PNFS_DS in some cases" * tag 'nfs-for-6.6-4' of git://git.linux-nfs.org/projects/anna/linux-nfs: NFSv4.1: fixup use EXCHGID4_FLAG_USE_PNFS_DS for DS server pNFS/flexfiles: Check the layout validity in ff_layout_mirror_prepare_stats pNFS: Fix a hang in nfs4_evict_inode() NFS: Fix potential oops in nfs_inode_remove_request() nfs42: client needs to strip file mode's suid/sgid bit after ALLOCATE op
2023-10-21Merge tag 'fsnotify_for_v6.6-rc7' of ↵Linus Torvalds1-8/+17
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fanotify fix from Jan Kara: "Disable superblock / mount marks for filesystems that can encode file handles but not open them (currently only overlayfs). It is not clear the functionality is useful in any way so let's better disable it before someone comes up with some creative misuse" * tag 'fsnotify_for_v6.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fanotify: limit reporting of event with non-decodeable file handles
2023-10-19iomap: fix short copy in iomap_write_iter()Jan Stancek1-3/+7
Starting with commit 5d8edfb900d5 ("iomap: Copy larger chunks from userspace"), iomap_write_iter() can get into endless loop. This can be reproduced with LTP writev07 which uses partially valid iovecs: struct iovec wr_iovec[] = { { buffer, 64 }, { bad_addr, 64 }, { buffer + 64, 64 }, { buffer + 64 * 2, 64 }, }; commit bc1bb416bbb9 ("generic_perform_write()/iomap_write_actor(): saner logics for short copy") previously introduced the logic, which made short copy retry in next iteration with amount of "bytes" it managed to copy: if (unlikely(status == 0)) { /* * A short copy made iomap_write_end() reject the * thing entirely. Might be memory poisoning * halfway through, might be a race with munmap, * might be severe memory pressure. */ if (copied) bytes = copied; However, since 5d8edfb900d5 "bytes" is no longer carried into next iteration, because it is now always initialized at the beginning of the loop. And for iov_iter_count < PAGE_SIZE, "bytes" ends up with same value as previous iteration, making the loop retry same copy over and over, which leads to writev07 testcase hanging. Make next iteration retry with amount of bytes we managed to copy. Fixes: 5d8edfb900d5 ("iomap: Copy larger chunks from userspace") Signed-off-by: Jan Stancek <jstancek@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-10-19Merge tag 'v6.6-rc7.vfs.fixes' of ↵Linus Torvalds1-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fix from Christian Brauner: "An openat() call from io_uring triggering an audit call can apparently cause the refcount of struct filename to be incremented from multiple threads concurrently during async execution, triggering a refcount underflow and hitting a BUG_ON(). That bug has been lurking around since at least v5.16 apparently. Switch to an atomic counter to fix that. The underflow check is downgraded from a BUG_ON() to a WARN_ON_ONCE() but we could easily remove that check altogether tbh" * tag 'v6.6-rc7.vfs.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: audit,io_uring: io_uring openat triggers audit reference count underflow
2023-10-19Merge tag 'ntfs3_for_6.6' of ↵Linus Torvalds16-82/+197
https://github.com/Paragon-Software-Group/linux-ntfs3 Pull ntfs3 fixes from Konstantin Komarov: - memory leak - some logic errors, NULL dereferences - some code was refactored - more sanity checks * tag 'ntfs3_for_6.6' of https://github.com/Paragon-Software-Group/linux-ntfs3: fs/ntfs3: Avoid possible memory leak fs/ntfs3: Fix directory element type detection fs/ntfs3: Fix possible null-pointer dereference in hdr_find_e() fs/ntfs3: Fix OOB read in ntfs_init_from_boot fs/ntfs3: fix panic about slab-out-of-bounds caused by ntfs_list_ea() fs/ntfs3: Fix NULL pointer dereference on error in attr_allocate_frame() fs/ntfs3: Fix possible NULL-ptr-deref in ni_readpage_cmpr() fs/ntfs3: Do not allow to change label if volume is read-only fs/ntfs3: Add more info into /proc/fs/ntfs3/<dev>/volinfo fs/ntfs3: Refactoring and comments fs/ntfs3: Fix alternative boot searching fs/ntfs3: Allow repeated call to ntfs3_put_sbi fs/ntfs3: Use inode_set_ctime_to_ts instead of inode_set_ctime fs/ntfs3: Fix shift-out-of-bounds in ntfs_fill_super fs/ntfs3: fix deadlock in mark_as_free_ex fs/ntfs3: Add more attributes checks in mi_enum_attr() fs/ntfs3: Use kvmalloc instead of kmalloc(... __GFP_NOWARN) fs/ntfs3: Write immediately updated ntfs state fs/ntfs3: Add ckeck in ni_update_parent()
2023-10-19Merge tag 'for-6.6-rc6-tag' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "Fix a bug in chunk size decision that could lead to suboptimal placement and filling patterns" * tag 'for-6.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix stripe length calculation for non-zoned data chunk allocation
2023-10-19fanotify: limit reporting of event with non-decodeable file handlesAmir Goldstein1-8/+17
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 <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20231018100000.2453965-2-amir73il@gmail.com>
2023-10-19writeback, cgroup: switch inodes with dirty timestamps to release dying cgwbsJingbo Xu1-12/+29
The cgwb cleanup routine will try to release the dying cgwb by switching the attached inodes. It fetches the attached inodes from wb->b_attached list, omitting the fact that inodes only with dirty timestamps reside in wb->b_dirty_time list, which is the case when lazytime is enabled. This causes enormous zombie memory cgroup when lazytime is enabled, as inodes with dirty timestamps can not be switched to a live cgwb for a long time. It is reasonable not to switch cgwb for inodes with dirty data, as otherwise it may break the bandwidth restrictions. However since the writeback of inode metadata is not accounted for, let's also switch inodes with dirty timestamps to avoid zombie memory and block cgroups when laztytime is enabled. Fixes: c22d70a162d3 ("writeback, cgroup: release dying cgwbs by switching attached inodes") Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> Link: https://lore.kernel.org/r/20231014125511.102978-1-jefflexu@linux.alibaba.com Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19chardev: Simplify usage of try_module_get()Uwe Kleine-König1-1/+1
try_module_get(NULL) is true, so there is no need to check owner being NULL. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231013132441.1406200-2-u.kleine-koenig@pengutronix.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19ovl: rely on SB_I_NOUMASKChristian Brauner1-0/+8
In commit f61b9bb3f838 ("fs: add a new SB_I_NOUMASK flag") we added a new SB_I_NOUMASK flag that is used by filesystems like NFS to indicate that umask stripping is never supposed to be done in the vfs independent of whether or not POSIX ACLs are supported. Overlayfs falls into the same category as it raises SB_POSIXACL unconditionally to defer umask application to the upper filesystem. Now that we have SB_I_NOUMASK use that and make SB_POSIXACL properly conditional on whether or not the kernel does have support for it. This will enable use to turn IS_POSIXACL() into nop on kernels that don't have POSIX ACL support avoding bugs from missed umask stripping. Link: https://lore.kernel.org/r/20231012-einband-uferpromenade-80541a047a1f@brauner Acked-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs: store real path instead of fake path in backing file f_pathAmir Goldstein4-23/+30
A backing file struct stores two path's, one "real" path that is referring to f_inode and one "fake" path, which should be displayed to users in /proc/<pid>/maps. There is a lot more potential code that needs to know the "real" path, then code that needs to know the "fake" path. Instead of code having to request the "real" path with file_real_path(), store the "real" path in f_path and require code that needs to know the "fake" path request it with file_user_path(). Replace the file_real_path() helper with a simple const accessor f_path(). After this change, file_dentry() is not expected to observe any files with overlayfs f_path and real f_inode, so the call to ->d_real() should not be needed. Leave the ->d_real() call for now and add an assertion in ovl_d_real() to catch if we made wrong assumptions. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpegtt48eXhhjDFA1ojcHPNKj3Go6joryCPtEFAKpocyBsnw@mail.gmail.com/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231009153712.1566422-4-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs: create helper file_user_path() for user displayed mapped file pathAmir Goldstein4-5/+5
Overlayfs uses backing files with "fake" overlayfs f_path and "real" underlying f_inode, in order to use underlying inode aops for mapped files and to display the overlayfs path in /proc/<pid>/maps. In preparation for storing the overlayfs "fake" path instead of the underlying "real" path in struct backing_file, define a noop helper file_user_path() that returns f_path for now. Use the new helper in procfs and kernel logs whenever a path of a mapped file is displayed to users. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231009153712.1566422-3-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs: get mnt_writers count for an open backing file's real pathAmir Goldstein2-8/+34
A writeable mapped backing file can perform writes to the real inode. Therefore, the real path mount must be kept writable so long as the writable map exists. This may not be strictly needed for ovelrayfs private upper mount, but it is correct to take the mnt_writers count in the vfs helper. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231009153712.1566422-2-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19vfs: stop counting on gcc not messing with mnt_expiry_mark if not askedMateusz Guzik1-2/+2
So happens it already was not doing it, but there is no need to "hope" as indicated in the comment. No changes in generated assembly. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20231004111916.728135-3-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19backing file: free directlyChristian Brauner2-8/+4
Backing files as used by overlayfs are never installed into file descriptor tables and are explicitly documented as such. They aren't subject to rcu access conditions like regular files are. Their lifetime is bound to the lifetime of the overlayfs file, i.e., they're stashed in ovl_file->private_data and go away otherwise. If they're set as vma->vm_file - which is their main purpose - then they're subject to regular refcount rules and vma->vm_file can't be installed into an fdtable after having been set. All in all I don't see any need for rcu delay here. So free it directly. This all hinges on such hybrid beasts to never actually be installed into fdtables which - as mentioned before - is not allowed. So add an explicit WARN_ON_ONCE() so we catch any case where someone is suddenly trying to install one of those things into a file descriptor table so we can have a nice long chat with them. Link: https://lore.kernel.org/r/20231005-sakralbau-wappnen-f5c31755ed70@brauner Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19file: convert to SLAB_TYPESAFE_BY_RCUChristian Brauner5-45/+148
In recent discussions around some performance improvements in the file handling area we discussed switching the file cache to rely on SLAB_TYPESAFE_BY_RCU which allows us to get rid of call_rcu() based freeing for files completely. This is a pretty sensitive change overall but it might actually be worth doing. The main downside is the subtlety. The other one is that we should really wait for Jann's patch to land that enables KASAN to handle SLAB_TYPESAFE_BY_RCU UAFs. Currently it doesn't but a patch for this exists. With SLAB_TYPESAFE_BY_RCU objects may be freed and reused multiple times which requires a few changes. So it isn't sufficient anymore to just acquire a reference to the file in question under rcu using atomic_long_inc_not_zero() since the file might have already been recycled and someone else might have bumped the reference. In other words, callers might see reference count bumps from newer users. For this reason it is necessary to verify that the pointer is the same before and after the reference count increment. This pattern can be seen in get_file_rcu() and __files_get_rcu(). In addition, it isn't possible to access or check fields in struct file without first aqcuiring a reference on it. Not doing that was always very dodgy and it was only usable for non-pointer data in struct file. With SLAB_TYPESAFE_BY_RCU it is necessary that callers first acquire a reference under rcu or they must hold the files_lock of the fdtable. Failing to do either one of this is a bug. Thanks to Jann for pointing out that we need to ensure memory ordering between reallocations and pointer check by ensuring that all subsequent loads have a dependency on the second load in get_file_rcu() and providing a fixup that was folded into this patch. Cc: Jann Horn <jannh@google.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19vfs: shave work on failed file openMateusz Guzik3-1/+17
Failed opens (mostly ENOENT) legitimately happen a lot, for example here are stats from stracing kernel build for few seconds (strace -fc make): % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ------------------ 0.76 0.076233 5 15040 3688 openat (this is tons of header files tried in different paths) In the common case of there being nothing to close (only the file object to free) there is a lot of overhead which can be avoided. This is most notably delegation of freeing to task_work, which comes with an enormous cost (see 021a160abf62 ("fs: use __fput_sync in close(2)" for an example). Benchmarked with will-it-scale with a custom testcase based on tests/open1.c, stuffed into tests/openneg.c: [snip] while (1) { int fd = open("/tmp/nonexistent", O_RDONLY); assert(fd == -1); (*iterations)++; } [/snip] Sapphire Rapids, openneg_processes -t 1 (ops/s): before: 1950013 after: 2914973 (+49%) file refcount is checked as a safety belt against buggy consumers with an atomic cmpxchg. Technically it is not necessary, but it happens to not be measurable due to several other atomics which immediately follow. Optmizing them away to make this atomic into a problem is left as an exercise for the reader. v2: - unexport fput_badopen and move to fs/internal.h - handle the refcount with cmpxchg, adjust commentary accordingly - tweak the commit message Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20230926162228.68666-1-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs: simplify misleading code to remove ambiguity regarding ihold()/iput()Luís Henriques1-3/+1
Because 'inode' is being initialised before checking if 'dentry' is negative it looks like an extra iput() on 'inode' may happen since the ihold() is done only if the dentry is *not* negative. In reality this doesn't happen because d_is_negative() is never true if ->d_inode is NULL. This patch only makes the code easier to understand, as I was initially mislead by it. Signed-off-by: Luís Henriques <lhenriques@suse.de> Link: https://lore.kernel.org/r/20230928152341.303-1-lhenriques@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs/pipe: use spinlock in pipe_read() only if there is a watch_queueMax Kellermann1-11/+32
If there is no watch_queue, holding the pipe mutex is enough to prevent concurrent writes, and we can avoid the spinlock. O_NOTIFICATION_QUEUE is an exotic and rarely used feature, and of all the pipes that exist at any given time, only very few actually have a watch_queue, therefore it appears worthwile to optimize the common case. This patch does not optimize pipe_resize_ring() where the spinlocks could be avoided as well; that does not seem like a worthwile optimization because this function is not called often. Related commits: - commit 8df441294dd3 ("pipe: Check for ring full inside of the spinlock in pipe_write()") - commit b667b8673443 ("pipe: Advance tail pointer inside of wait spinlock in pipe_read()") - commit 189b0ddc2451 ("pipe: Fix missing lock in pipe_resize_ring()") Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Message-Id: <20230921075755.1378787-4-max.kellermann@ionos.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs/pipe: remove unnecessary spinlock from pipe_write()Max Kellermann1-9/+0
This reverts commit 8df441294dd3 ("pipe: Check for ring full inside of the spinlock in pipe_write()") which was obsoleted by commit c73be61cede ("pipe: Add general notification queue support") because now pipe_write() fails early with -EXDEV if there is a watch_queue. Without a watch_queue, no notifications can be posted to the pipe and mutex protection is enough, as can be seen in splice_pipe_to_pipe() which does not use the spinlock either. Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Message-Id: <20230921075755.1378787-3-max.kellermann@ionos.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs/pipe: move check to pipe_has_watch_queue()Max Kellermann1-9/+3
This declutters the code by reducing the number of #ifdefs and makes the watch_queue checks simpler. This has no runtime effect; the machine code is identical. Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Message-Id: <20230921075755.1378787-2-max.kellermann@ionos.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19fs: add a new SB_I_NOUMASK flagJeff Layton3-24/+3
SB_POSIXACL must be set when a filesystem supports POSIX ACLs, but NFSv4 also sets this flag to prevent the VFS from applying the umask on newly-created files. NFSv4 doesn't support POSIX ACLs however, which causes confusion when other subsystems try to test for them. Add a new SB_I_NOUMASK flag that allows filesystems to opt-in to umask stripping without advertising support for POSIX ACLs. Set the new flag on NFSv4 instead of SB_POSIXACL. Also, move mode_strip_umask to namei.h and convert init_mknod and init_mkdir to use it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Message-Id: <20230911-acl-fix-v3-1-b25315333f6c@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-18NFSv4.1: fixup use EXCHGID4_FLAG_USE_PNFS_DS for DS serverOlga Kornievskaia1-2/+0
This patches fixes commit 51d674a5e488 "NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server", purpose of that commit was to mark EXCHANGE_ID to the DS with the appropriate flag. However, connection to MDS can return both EXCHGID4_FLAG_USE_PNFS_DS and EXCHGID4_FLAG_USE_PNFS_MDS set but previous patch would only remember the USE_PNFS_DS and for the 2nd EXCHANGE_ID send that to the MDS. Instead, just mark the pnfs path exclusively. Fixes: 51d674a5e488 ("NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server") Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>