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6 daysMerge tag 'vfs-7.4-rc1.fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: - writeback: - Update dirtied_when instead of dirtied_time_when when a wb switch puts an inode at the newest end of the target b_dirty list. The list was left out of order so move_expired_inodes() could stop before older inodes, and the lazytime expiration timestamp was reset - Clear the old wb's dirty-I/O state and bandwidth contribution when a batch of inode switches leaves its dirty lists empty. An empty wb stayed scheduled for periodic writeback and inflated bdi->tot_write_bandwidth - Take wb_switch_rwsem across the inode scan of cleanup_offline_cgwb(). The v7.3-rc5 fix that rotates scanned inodes let a scan racing a sync()'s queue_io() move lazytime inodes past the sync's cutoff, so sync() returned without persisting their timestamps - Don't kick writeback for an IOCB_DONTCACHE write on an inode that has no wb yet. With cgroup writeback an O_DIRECT RWF_DONTCACHE write to a block device dereferenced NULL - statmount/listmount/listns: - Refuse statmount() string requests with a buffer that isn't larger than struct statmount - Don't wrap around with a U64_MAX cursor in listmount() and listns() - Don't end listns() at an inactive namespace - Only add init_ipc_ns and init_net to the namespace trees if CONFIG_IPC_NS and CONFIG_NET_NS are enabled - iomap: - Only mark blocks uptodate in __iomap_write_begin() after reading them and let __iomap_write_end() mark the zeroed blocks uptodate once the copy from userspace succeeded - Check a chunk against max_integrity_io_size() on its own before the bio size check - Only enforce block alignment for direct I/O into holes and unwritten extents if IOMAP_DIO_FSBLOCK_ALIGNED is set - backing-file: - Check S_APPEND and S_IMMUTABLE on the backing inode. FUSE passthrough opens the backing file with vfs_open() which skips may_open(), so anyone who may open the FUSE file for writing could overwrite an append-only backing file anywhere or write to an immutable one. Open, mmap and writes now check the backing inode the way may_open() and do_mmap() do - Always call kiocb_end_write() for a queued write - Let backing files inherit FMODE_NONOTIFY from the user file. The event fds fanotify creates for permission events on a stacked filesystem raised FS_OPEN_PERM on the real path from inside the listener's read() and deadlocked listeners with marks on both layers - pidfs: - Look the task up before checking for exit information in PIDFD_GET_INFO and start over if the task no longer owns the pid once all fields have been read. A caller racing release_task() got neither PIDFD_INFO_PID nor PIDFD_INFO_EXIT or ESRCH although the exit information was available, and a caller racing a sub-thread's exec reported that thread's tid as the pid - Clear the mask bits of fields that lie beyond the struct size the caller passed. The uapi header promises that the mask names no such field but a caller passing PIDFD_INFO_SIZE_VER0 got the coredump and supported mask bits set for fields that were never written - aio: - Give the aio ring a ->read_folio that fails with EIO so a fault on a ring whose file was truncated gets SIGBUS instead of jumping to NULL - Check nr_events against the ring size before doubling it in ioctx_alloc() - splice: - Only write back an implicit file position in do_splice() when the splice helper succeeded. splice doesn't take f_pos_lock so a failed splice restored a stale snapshot over a position that a concurrent getdents() had moved. On ext2 the next readdir then trusted an offset inside a directory entry - Retry tee() when the input pipe was emptied or the output pipe filled between the prep steps and link_pipe() instead of returning 0 while the input pipe still has writers, as splice_pipe_to_pipe() does - ucount: - Take the reference that pins a ucounts level on the 0 -> 1 transition before checking the rlimit - Read the parent ucounts before dropping the rlimit count in do_dec_rlimit_put_ucounts() - inode: - Rotate inodes whose page cache couldn't be dropped to the tail of the LRU - Skip inodes that another LRU walker is isolating - setns: - Set nsset->flags before anything in prepare_nsset() can fail so the error path drops the cred prepared for CLONE_NEWUSER. A failing setns() with CLONE_NEWUSER and CLONE_NEWNS leaked it together with its user namespace - Refuse setns(CLONE_NEWNS) for a task that shares its fs_struct again when more namespaces are requested - minix: - Restore uptodate on the pinned bitmap buffers before redirtying them after a failed writeback instead of tripping the warning in mark_buffer_dirty(), as ext2 and ext4 do for their superblock buffers - Reject rmdir() of a directory with a corrupted link count with EFSCORRUPTED instead of hitting the drop_nlink() warning - userns: Keep the exec securebits and their locks when creating or joining a user namespace. set_cred_user_ns() reset all securebits to SECUREBITS_DEFAULT so anyone who may create a user namespace could shed SECBIT_EXEC_RESTRICT_FILE and SECBIT_EXEC_DENY_INTERACTIVE with a single unshare(CLONE_NEWUSER) - fs: Honor FOP_UNSIGNED_OFFSET in sys_llseek() and in the pread64(), pwrite64(), preadv() and pwritev() wrappers - proc/kcore: Advance the vmalloc retry in read_kcore_iter() by the last vread_iter() copy instead of the running total - eventpoll: Return the error when the wakeup source for EPOLLWAKEUP can't be created in EPOLL_CTL_MOD instead of reporting success without suspend protection - coredump: Mark do_coredump() noinline_for_stack - nsfs: Check the trailing bytes of a namespace file handle in bytes instead of words - netfs: Restore the per-level and per-point decoding of the debug mask - exportfs: Release the directory file get_name() opened with __fput_sync(). From nfsd's kernel threads the deferred fputs arrived faster than delayed_fput retired them and each pinned the directory's readdir state, growing unreclaimable slab by about 90 MB per second under a parallel tree walk - fs: Call ramfs_kill_sb() for a ramfs rootfs. Since rootfs can be unmounted as of v7.0 its struct ramfs_fs_info was leaked - signal: Check the blocked mask for every entry dequeue_synchronous_signal() looks at. The scan could select a blocked synchronous signal and deliver it while blocked - super: Convert the superblock device table from an rhltable to a plain hashtable under a spinlock. This fixes a bug from v7.3 where fs_bdev_freeze() froze a btrfs filesystem through a stale member that open_ctree() had already released while the freeze was waiting for SB_BORN - fork: Leave rcu_users at zero until copy_process() can't fail anymore. bpf_task_acquire() handed out trusted references to the new task from the task_alloc LSM hook and sched_ext's ops.init_task() and a failing fork freed the task behind them - xattr: Always run cap_convert_nscap() for a security.capability write. A zero-length setxattr() skipped it and let an unprivileged caller without CAP_SETFCAP or write permission on the file plant an empty security.capability xattr that made every execve() of the binary fail with EINVAL - namei: Skip the S_ISDIR assertion in - proc: Refuse to mount on entries below /proc/<pid>/net like fd/, fdinfo/ and map_files/. proc_net_d_revalidate() always fails so the first lookup by anyone with search permission ran d_invalidate() on the dentry and detached every mount on it, locked mounts included - libfs: Hold one mount reference for all pins instead of one per pin. The pin count is what keeps the mount alive, so the per-pin reference only cost a mntget() and a mntput() through mntput_no_expire_slowpath() for every debugfs, tracefs, securityfs or configfs file that comes and goes - iov_iter: Return 0 from iov_iter_alignment() for an empty iterator of any type - watch_queue: Give info_id its own storage instead of overlaying it with rcu_head - filelock: Take an active superblock reference while waiting for a delegation break. After a lazy umount closing the delegation holder could shut down the superblock under the waiter whose final iput() then ran shmem_evict_inode() on freed state - fs: Skip the copy_file_range() write limit checks when there is no data to copy - bpf: Allow bpf_d_path() from fentry on filp_close_sync(). Since close_range() became synchronous this cycle close(), close_range() and the closes on exec and exit no longer go through filp_close(). fexit stays rejected since the file may be gone by then - fs_pin: Dequeue the wait entry unconditionally in pin_kill(). A spuriously woken waiter kept its on-stack entry queued, took that as proof that the pin was alive and used the freed acct structure when umount() of the accounting file raced acct(2) - dcache: Don't fail __d_obtain_alias() for an inode without links and aliases. The ESTALE check added this cycle broke open_by_handle_at() and nfsd file handle decoding on NFS and FUSE where i_nlink is just what the server last reported and the handle may well still be valid - selftests/ovl: Fix the mountinfo expectations of the detached layer test which has failed since it was added * tag 'vfs-7.4-rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (60 commits) fs: don't fail __d_obtain_alias() for unlinked inodes ns: don't add init_ipc_ns and init_net without namespace support aio: avoid request count overflow in ioctx_alloc() selftests/ovl: fix detached layer mountinfo expectations bpf: Allow bpf_d_path() from filp_close_sync() fs: skip copy_file_range write limits when there is no data minix: reject rmdir of a directory with a corrupted link count fs_pin: do not trust the pin after a spurious wakeup in pin_kill() ucount: read the parent ucounts before dropping the rlimit count splice: retry tee() instead of returning 0 when it races selftests/pidfd: test that fields beyond the struct size are not reported pidfs: do not report fields that do not fit into the caller's struct fs: let backing files inherit FMODE_NONOTIFY from the user file splice: avoid stale f_pos writeback on error backing-file: always end a queued write filelock: keep superblock active through delegation wait watch_queue: keep info_id separate from rcu_head iomap: only follow dio alignment requirement if specified iov_iter: fix NULL deref in iov_iter_alignment() backing-file: enforce append-only and immutable backing inodes ...
9 daysMerge tag 'for-7.4/io_uring-dmabuf-20261023' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull io_uring dma-buf support from Jens Axboe: "This adds native dma-buf support to the I/O path, exposed through io_uring. It's been in development for a while and should be ready to go now. - dma-buf file I/O infrastructure: a dma_buf_io_ctx created through a new ->init_dma_buf_io_ctx file operation, and a dma_buf_io_map holding the device DMA mapping. The two are split so a mapping can be invalidated and re-established underneath a live context, with the map counting in-flight requests so it can be torn down safely. - A new iov_iter type for dmabuf maps, and a dma map backed bio type for the block layer, with raw block device support on top. - nvme-pci backend implementing dma-buf backed requests, including SGL support. - io_uring dmabuf backed registered buffers, built on a reworked buffer registration structure with an extended update path, regbuf import flags, an uncloneable flag for buffer types that can't be cloned, and cloning support for registered dma-bufs" * tag 'for-7.4/io_uring-dmabuf-20261023' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: io_uring/dma-buf: don't fail fixed buffers without dma-buf support nvme-pci: detach dma-bufs only on removal block: reject dma-bufs larger than 4GiB io_uring/dma-buf: allow cloning registered dma-bufs dma-buf-io: document dma_buf_io_init_map dma-buf-io: fix typos in kernel docs block: fix indention for dma-buf checks io_uring/rsrc: add dmabuf backed registered buffers io_uring/rsrc: add regbuf import flags io_uring/rsrc: add uncloneable regbuf flag io_uring/rsrc: extend buffer update io_uring/rsrc: introduce buf registration structure nvme-pci: add SGL support for the dmabuf path nvme-pci: implement dma-buf backed requests nvme-pci: rename nvme_pci_sgl_set_data to nvme_pci_dma_iter_set_sgl block: add dma-buf support for raw bdev block: introduce dma map backed bio type block: always adjust bi_offset on bio_advance_iter iov_iter: add iterator type for dmabuf maps dma-buf: introduce initial file I/O infrastructure
2026-10-22Merge patch series "writeback: fix timestamp and dirty-state handling in wb ↵Christian Brauner
switches" Julian Sun <sunjunchao@bytedance.com> says: This series fixes two issues when moving inodes between writeback structures: 1. Update dirtied_when rather than dirtied_time_when when inserting an inode at the newest end of the target dirty list. This maintains the list ordering without resetting the lazytime expiration timestamp. 2. Clear the source wb's dirty-I/O state and bandwidth contribution when inode migration leaves its dirty-I/O lists empty. * patches from https://patch.msgid.link/20261016115230.3640770-1-sunjunchao@bytedance.com: writeback: clear old wb dirty state after inode switches writeback: reset dirtied_when when switching wbs Link: https://patch.msgid.link/20261016115230.3640770-1-sunjunchao@bytedance.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-10-21writeback: reset dirtied_when when switching wbsJulian Sun
When switching a dirty inode to another wb, inode_do_switch_wbs() puts it at the newest end of the target b_dirty list instead of searching for its sorted position. This requires updating dirtied_when, which move_expired_inodes() uses to decide where to stop scanning. However, the switch updates dirtied_time_when instead. This leaves b_dirty out of order and can make the scan stop before reaching older inodes. It also resets the lazytime expiration timestamp, potentially delaying timestamp writeback. Update dirtied_when instead, preserving both the constant-time insertion and the lazytime expiration timestamp. Correct the field name in the comment and document the distinction between the two inode timestamps. Fixes: 9a6ebbdbd412 ("writeback: Avoid excessively long inode switching times") Cc: stable@vger.kernel.org Signed-off-by: Julian Sun <sunjunchao@bytedance.com> Link: https://patch.msgid.link/20261016115230.3640770-2-sunjunchao@bytedance.com Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-10-19Merge tag 'vfs-7.4-rc1.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Fixes: - aio: a keyed poll completion on an epoll instance could recurse into the same epoll waitqueue lock when the result eventfd is watched by that very instance. An unprivileged process could make a CPU spin on the recursive lock. eventfd-backed poll completions are always deferred now. - fsnotify_inoderemove() is only called once the inode is really dead, no nlink and no aliases, and open_by_handle_at() can't add an alias to a dead inode anymore. The race could crash fsnotify or lose inode mark notifications. - devtmpfs: the conversion of the public instance to ->get_tree() broke reconfiguring the shared superblock's options on later mounts which made the boot time defaults permanent. A reconfigure context is kept in fc->fs_private so the parse ops can forward options to the underlying filesystem. - ufs truncated the 64-bit directory size to an unsigned int in ufs_last_byte(). A crafted image with a 4 GiB directory produced an out-of-folio read in ufs_find_entry() and, with CONFIG_UFS_FS_WRITE, a write into an adjacent page. - devpts rejects max=0 instead of silently lifting the per-instance pty limit. The value wrapped into ida_alloc_max() and became unlimited. - fs_pin publishes pins with the rcu list helpers so the kill paths reading the lists under rcu see the initialization. - dentry_kill() reports a Tasks-RCU quiescent state. Its cond_resched() is the only reschedule point on the dentry teardown path and cond_resched() isn't a quiescent state for Tasks-RCU, so Meta kept seeing rcu_tasks stalls in btrfs subvolume deletion. - writeback sizes foreign flushes by the target wb's dirty pages instead of the memcg-wide count which over or undersized a single bdi flush. - nfsd READ emitted two fsnotify access events on the iterator path since vfs_iocb_iter_read() already sends one. A READ on a krb5i or krb5p mount showed up twice in inotify. - pipe and splice pass a poll key when waking readers and writers so epoll, poll() and select() waiters only wake for the event they asked for. - the iso8859-14 Unicode to charset tables had page01 duplicated as page1e so 29 code points mapped to the wrong bytes and 22 that aren't in the charset were accepted. - orangefs doesn't wait for an unmount service operation that never returns on system shutdown and uses ssize_t for strscpy() errors. - __register_chrdev() checks the kobject_set_name() return value. - selftest fixes: the openat2 tests hardcoded O_LARGEFILE to 0x8000 which is O_NOFOLLOW on powerpc, resolve_test makes /tmp a mountpoint so RESOLVE_NO_XDEV has a boundary to trip over, file_stressor moves into its own directory with a 30 minute timeout, the kernfs listxattr test skips when SELinux exposes security.selinux, the namespaces active reference tests wait for the thread via a PIDFD_THREAD pidfd since pthread_join() returns before exit_nsproxy_namespaces(), the idmapped_tmpfile test chowns its directory into the mapped range, the clone3 CLONE_CLEAR_SIGHAND test adds CLONE_VM so it fails for the intended reason, the pidfd PPID error message prints the values it compares and fscontext_ns gets a .gitignore. Cleanups: - vmcore prints the release of the crashed kernel from the VMCOREINFO note so a kdump that dies before the dump lands still says which kernel it was for. - initramfs allocates hardlink hash entries with the validated cpio name length instead of PATH_MAX, which put every entry in kmalloc-8k. - the unused dax_layout_busy_page() is removed, dax_layout_busy_page_range() becomes static and dax_folio_init() drops a redundant list initialization. - vfs_empty_path() is removed, it has had no callers since getname_maybe_null(). - comment and documentation fixes in aio, bpf_fs_kfuncs, fs-writeback, inode, read_write, squashfs and the vfs.rst copy of struct file_system_type" * tag 'vfs-7.4-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits) selftests/filesystems: Fix idmapped_tmpfile layer dir ownership selftests/namespaces: Wait for thread exit via pidfd in active-ref tests writeback: size foreign flushes by target wb dirty pages initramfs: Reduce hardlink hash allocation sizes fs: remove unused vfs_empty_path() dcache: report a Tasks-RCU quiescent state in dentry_kill() vmcore: report the release of the crashed kernel splice: pass a poll key when waking pipe readers and writers pipe: pass a poll key when waking writers after a resize orangefs: use ssize_t instead of size_t for error codes... orangefs_super: don't wait on service operation on system shutdown. docs/vfs: Fix the struct file_system_type copy nls: fix the Unicode to charset tables of iso8859-14 selftests/filesystems/openat2: make /tmp a mountpoint inside private namespace selftests/filesystems/openat2: fix O_LARGEFILE definitions for non-arm64 architectures fs: fix misleading comments in read_write.c squashfs: fix inode number description in documentation fs: fix typos in comments fs/dax: Make dax_layout_busy_page_range() static fs/dax: Remove unused dax_layout_busy_page() ...
2026-10-19Merge tag 'vfs-7.4-rc1.lookup' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull path lookup updates from Christian Brauner: "This prepares for Neil's changes to directory locking. The goal is for the VFS to lock the dentry and not the parent directory and to push the i_rwsem parent locking down into the filesystems where it can be kept, removed or adjusted as each filesystem sees fit. The next step in that is to swap the lock order of d_alloc_parallel() and i_rwsem so code can wait on i_rwsem while holding an in-lookup dentry. Two things have to change before that can happen. Nobody may call d_alloc_parallel() while holding i_rwsem, and nobody may d_drop() a dentry while it is being worked on since that effectively unlocks an in-lookup dentry and lets another one be allocated too early. So d_splice_alias() learns to handle hashed dentries in addition to unhashed and in-lookup ones, which is what ->atomic_open() needs and removes the reason filesystems d_drop() first. d_alloc_trylock() is a non-blocking d_alloc_parallel() for the filesystems that prime the dcache from readdir, smb, nfs, fuse and ceph, where waiting for a concurrent lookup is pointless. d_duplicate() creates an in-lookup dentry with the name of an existing one for silly-rename and whiteouts. LOOKUP_SHARED tells ->lookup() how the parent is locked so it can drop and retake it. DCACHE_PAR_LOOKUP is tracked by lockdep now with a per filesystem type key, and overlayfs gets its own class since it stacks over itself. And a d_flags bit is reserved for filesystem private use. Also included is Mateusz's fix for the spurious dentry reference cycle on open. __legitimize_path() grabs a reference, do_dentry_open() grabs another and terminate_walk() drops the first. do_dentry_open() consumes the held reference now. Opening the same file read-only on a 20-core VM goes from 4,043,375 to 5,629,378 ops/s in will-it-scale" * tag 'vfs-7.4-rc1.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: VFS: d_duplicate: repair comments to avoid kernel-doc warnings ovl: provide private lockdep class for dentry->dep_map VFS: rename lookup_map to dep_map VFS: per-fs-type lockdep key for dentry in-lookup locking VFS: reserve a d_flags bit for fs-specific usage VFS: add lockdep monitoring of DCACHE_PAR_LOOKUP lock. VFS: Add LOOKUP_SHARED flag. VFS: add d_duplicate() VFS: introduce d_alloc_trylock() VFS: enhance d_splice_alias() to handle hashed dentries VFS: fix various typos in documentation for start_creating start_removing etc fs: avoid spurious dentry ref/unref cycle on open
2026-10-19Merge tag 'vfs-7.4-rc1.idmap' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs idmap constification from Christian Brauner: "This makes struct mnt_idmap const throughout the tree. A mount's idmapping is immutable. The only thing modified after alloc_mnt_idmap() is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only reads from it. That is the same model struct cred uses and the idmapping is sensitive enough to deserve it. The conversion goes bottom up through the vfs{g,u}id and fs{g,u}id helpers, the privilege checks, acl, xattr and quota and then every inode operation that takes an idmap, so ->permission(), ->getattr(), ->setattr(), ->create(), ->mkdir(), ->mknod(), ->symlink(), ->rename(), ->tmpfile(), ->get_acl(), ->set_acl() and ->fileattr_set() with their implementations in every filesystem, plus the LSM hooks. struct vfsmount, struct mount_kattr and struct kstatmount store a const pointer and nop_mnt_idmap and invalid_mnt_idmap live in rodata, so anything that tries to modify them faults instead of silently corrupting the initial idmapping" * tag 'vfs-7.4-rc1.idmap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits) fs: make nop_mnt_idmap and invalid_mnt_idmap const fs: port mnt_idmap() and file_mnt_idmap() to const mnt_idmap fs: port vfs_*() helpers to const mnt_idmap fs: port ->setattr() to pass const mnt_idmap fs: port ->getattr() to pass const mnt_idmap fs: port ->create() to pass const mnt_idmap fs: port ->symlink() to pass const mnt_idmap fs: port ->mkdir() to pass const mnt_idmap fs: port ->rename() to pass const mnt_idmap fs: port ->mknod() to pass const mnt_idmap fs: port ->tmpfile() to pass const mnt_idmap fs: port ->get_acl() to pass const mnt_idmap fs: port ->set_acl() to pass const mnt_idmap fs: port ->fileattr_set() to pass const mnt_idmap fs: port xattr to const mnt_idmap fs: port ->permission() to pass const mnt_idmap fs: port acl to const mnt_idmap fs: port inode_init_owner() to const mnt_idmap fs: port inode_owner_or_capable() to const mnt_idmap fs: port privilege checking helpers to const mnt_idmap ...
2026-10-16VFS: per-fs-type lockdep key for dentry in-lookup lockingNeilBrown
Stacked file-systems might call d_alloc_parallel() in another file-system while holding an in-lookup dentry is this filesystem. In order for lockdep not to report that, we give each file-system-type a different lockdep key for in-lookup locking. This matches what is already done for lockdep tracking of i_rwsem. Fixes: 59492f9991dc ("VFS: add lockdep monitoring of DCACHE_PAR_LOOKUP lock.") Signed-off-by: NeilBrown <neil@brown.name> Link: https://patch.msgid.link/20261002223746.3248726-2-neilb@ownmail.net Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-10-14dma-buf: introduce initial file I/O infrastructurePavel Begunkov
The goal is to be able to natively use dma-buf in the read-write / IO path. This patch adds basic building blocks serving as a glue and API between drivers and upper layer subsystems providing the uAPI. Later patches implement it for NVMe raw block devices and expose it to the user space via io_uring. There are two main objects. struct dma_buf_io_ctx and struct dma_buf_io_map. The ctx is used during initial registration and serves as an interface between the upper layer user like io_uring and to the importer subsystem / driver. The map represents the actual dma map established for the target device[s] with dma_buf_map_attachment() and stored in a device specific format. The context is created via a new file operation ->init_dma_buf_io_ctx. The ctx-map separation exists to facilitate map invalidation (see dma_buf_io_invalidate_mappings()). A ctx can create multiple maps during its lifetime, but there can only be no more than one (active) map attached to it. Invalidation drops the active map if present, and any new I/O request will try to create a new one. The primary task of dma_buf_io_map is to count requests using it and wait for their completion when we want to destroy the DMA map. [un]mapping and any work with dma addresses is delegated to the importer driver via an ops table stored in the ctx, see struct dma_buf_io_ops. Only the target driver / subsystem knows about devices it wants to use the dma-buf with, especially in case of multi-device filesystems or stacking in the future. Acked-by: Matthew Brost <matthew.brost@intel.com> Tested-by: Matthew Brost <matthew.brost@intel.com> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/49e24334953262e85d5616c9afde88c680e4f3a3.1791975048.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-10-04readdir: take no inode lock on an immutable directoryChristian Brauner
iterate_dir() takes the directory's i_rwsem shared and holds it across ->iterate_shared(). For a directory that never has an entry and is never removed the lock keeps nothing still, it only orders every reader and every writer of that inode behind each other. For the directory of a nullfs instance that matters. The instance of the initial mount namespace is the root of every empty mount namespace and the private instance is the root of every kernel thread, so one inode is shared across users who have nothing else in common. And a reader can hold the lock for as long as it likes: back the getdents() buffer with a mapping of a file on a FUSE mount of your own, let the copy of "." and ".." fault and let the server wait. Queue an exclusive taker behind it, a mkdir() in that directory goes through start_dirop() before the read-only mount is reported, and from then on every lookup that misses the dcache in that directory, every create and every mount on it waits until the server answers. One user of an empty mount namespace stalls all the others. Add FOP_IMMUTABLE for the file operations of a directory that never changes and is never removed and let iterate_dir() skip the lock for it. The flag never changes for a file, ->f_pos is protected by f_pos_lock since directories are FMODE_ATOMIC_POS, IS_DEADDIR can't be set on such a directory and neither touch_atime() nor fsnotify take i_rwsem. Set it on the nullfs directory. The placeholder directories of libfs never have an entry either but their owners remove them, so they keep the lock. Fixes: 9d4e752a24f7 ("namespace: allow creating empty mount namespaces") Cc: stable@vger.kernel.org # v7.1+ Link: https://patch.msgid.link/20261002-work-mount-fixes-4-v1-19-dd44b89d44ce@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-10-04fsnotify: let a filesystem refuse marks on its objectsChristian Brauner
Don't let nullfs be watched. fanotify refuses mount and filesystem marks on SB_NOUSER superblocks but inode marks of inotify, fanotify and dnotify go through. The one inode of knullfs is the root of every kernel thread and the following patches make it reachable from userspace as the directory that stands in for an unmounted mount. A watch placed through one such directory would report the opens through all the others, across users. Add FS_DISALLOW_NOTIFY next to FS_DISALLOW_NOTIFY_PERM, refuse a mark on any object of such a filesystem in fsnotify_add_mark_list() where every backend ends up and set it for nullfs. There's nothing to watch on a permanently empty and immutable filesystem. Link: https://patch.msgid.link/20261002-work-mount-fixes-4-v1-16-dd44b89d44ce@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-25fs: remove unused vfs_empty_path()Sang-Heon Jeon
Since commit e896474fe485 ("getname_maybe_null() - the third variant of pathname copy-in"), vfs_empty_path() has no callers. So remove it. No functional change. Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Link: https://patch.msgid.link/20260918165105.1013792-1-ekffu200098@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port mnt_idmap() and file_mnt_idmap() to const mnt_idmapChristian Brauner
Now that everything takes a mnt_idmap as const store a const pointer in struct vfsmount, struct mount_kattr and struct kstatmount and return one from mnt_idmap(), file_mnt_idmap() and ovl_upper_mnt_idmap(). Finally, also make mnt_idmap_get() return a const pointer. Also convert the remaining local variables that are initialized from the accessors. alloc_mnt_idmap() keeps returning a non-const pointer. It is the only place where an idmapping is actually written to. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-26-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port vfs_*() helpers to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-25-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->setattr() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-24-54ccd48e100b@kernel.org Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->getattr() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-23-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->create() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-22-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->symlink() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-21-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->mkdir() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-20-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->rename() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-19-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->mknod() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-18-54ccd48e100b@kernel.org Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->tmpfile() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-17-54ccd48e100b@kernel.org Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->get_acl() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-16-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->set_acl() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-15-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->fileattr_set() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-14-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port xattr to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-13-54ccd48e100b@kernel.org Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port ->permission() to pass const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-12-54ccd48e100b@kernel.org Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port inode_init_owner() to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-10-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port inode_owner_or_capable() to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-9-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port privilege checking helpers to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-8-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port i_{g,u}id_{needs_}update() to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-6-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port i_{g,u}id_into_vfs{g,u}id() to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-5-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-23fs: port fs{g,u}id helpers to const mnt_idmapChristian Brauner
Convert to const struct mnt_idmap. A mount's idmapping is immutable. The only thing that is allowed to be modified afterwards is the reference count and that is hidden behind mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads from the idmapping. This is the same model that struct cred uses and the idmapping is also rather sensitive. So make the idmap argument const wherever we can. The conversion is done from the bottom up so callers can continue to pass a non-const pointer to a const parameter until the conversion is finished. No functional changes. Link: https://patch.msgid.link/20260901-work-idmap-const-v1-4-54ccd48e100b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Seth Forshee <sforshee@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-10fs: fix typos in commentsHemanth Selam
Fix typos in comments, reported by scripts/checkpatch.pl using the misspelling list in scripts/spelling.txt. Only touches comments, no code changes. Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com> Link: https://patch.msgid.link/20260907063252.21433-1-hemanth.selam@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-08-27Merge tag 'mm-stable-2026-08-26-15-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff" (Lorenzo Stoakes) Index MAP_PRIVATE file-backed folios by their anonymous page offset to resolve confusion around reverse mapping for zeroed and CoW'd file-backed memory. Use this new VMA anonymous page offset tracking to eliminate index conflicts and lay the foundation for scalable CoW performance improvements. - "promote mapped executable folios after first usage for MGLRU" (Baolin Wang) Make MGLRU's protection of mapped executable file folios more reliable. Follow the classical LRU's logic, promoting mapped executable file folios after their first usage to give executable code a better chance to stay in memory and improve workload performance. - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen) Fix per-node proactive reclaim interface's ignoring the swappiness parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness() into a single function that checks proactive_swappiness regardless of kernel configuration. - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance cost" (Usama Arif) Reduce lru_lock contention in the reclaim path by deriving scan-balance costs from vmstat counters rather than lock-acquired producer updates. Read and decay these cost signals on the reclaim side under a dedicated per-lruvec lock, reducing total LRU lock wait time by over 60% without impacting scan throughput. - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky) Fix two low-risk zram bugs which Sashiko spotted in drive-by review. - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's memcg" (Zi Yan) Fix xas_split_alloc() by enabling target folio memcg charging during splits and adding the missing __GFP_ACCOUNT flag for proper XArray node memory accounting. - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick) Replace hardcoded binary names in selftests/mm/.gitignore with a generic pattern-matching rule to automatically ignore generated test files and avoid manual updates when adding new tests. - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon) Make the incompatibility between FLATMEM and NUMA explicit in mm/Kconfig and remove the unused pgdat_page_ext_init() function. - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang) Clean up zram compression backends by removing redundant error cleanup, adding parameter and dictionary validation, auto-prefixing algorithm error logs, and resetting parameters prior to reinitialization. - "zram: fix stale scan bounds after reinitialization" (Longlong Xia) Prevent out-of-bounds slot accesses during concurrent zram resets by moving table scan bound calculations under dev_lock in writeback_store() and read_block_state(). - "add anon mTHP collapse test cases" (Baolin Wang) Extend selftests helper functions to support arbitrary page orders and add new test cases and options for mTHP collapse in khugepaged. - "selftests/mm: Handle unsupported and transient test conditions" (Muhammad Usama Anjum) Update MM selftests to report a SKIP status instead of a failure when required kernel or filesystem features are unsupported, while adding retry logic for transient page migration errors. - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia) Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled and extend shrink_memcg() to support batch writeback for improved writeback efficiency. - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan) Introduce an IOCTL-based binary interface for memory allocation profiling that enables kernel-side filtering before per-CPU counter aggregation. This eliminates the text-parsing overhead of /proc/allocinfo and provides up to a 20x speedup by transferring only filtered allocation data to userspace. - "better block swap batching and a different take on swap_ops v5" (Christoph Hellwig) Refactor block swap I/O to use swap_iocb for batching instead of single-bio requests and rebase the swap_ops interface, achieving faster swap throughput during kernel builds. - "mm: kmemleak: reduce transient false positives by confirming leaks" (Catalin Marinas) Reduce false-positive kmemleak reports by combining two kmemleak enhancements that add a second confirmation scan and a configurable minimum unreferenced scan count module parameter. - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels" (Breno Leitao) Auto-scanning kernels can generate false-positive memory leak reports on single scans, so this patch defaults min_unref_scans to 2 when CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming scan. - "swap_ops updates" (Christoph Hellwig) Batching I/O for synchronous swap devices causes performance regressions and filesystem-based swap suffers from double-indirection overhead. This series resolves both issues by reintroducing per-folio writes for synchronous swap and allowing filesystems to directly export their own swap_ops. - "mm/khugepaged: several cleanups" (Nico Pache) khugepaged accumulated redundant state-checking patterns and outdated comments following mTHP integration. Introduce dedicated helpers for PTE validation and event counting while refreshing the internal documentation. - "maple_tree: lock checking and clean ups" (Liam Howlett) Syzbot reports incorrectly blame memory management exit paths for locking bugs, maple tree erase operations risk allocation failures without gfp flags and internal documentation lacks clarity. Improve lock error detection, update docs, fix race and allocation edge cases and optimize erase allocations using a fallback to GFP_KERNEL | GFP_NOFAIL. * tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits) selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC memcg: move LRU size accounting on reparenting instead of copying it mm/vmscan: fix comment logic in balance_pgdat maple_tree: add helper mas_make_walkable() maple_tree: avoid extra gap calculation maple_tree: fix argument name in header maple_tree: change two GFP flags in tests maple_tree: document erase and allocations better maple_tree: avoid mas_erase() and mtree_erase() failures maple_tree: document that erase may use GFP_KERNEL for allocations maple_tree: catch race in mas_alloc_cyclic() maple_tree: add bulk parent set helper maple_tree: micro optimisation of mas_wr_store_type() maple_tree: optimise mas_wr_node_store() when not in rcu mode maple_tree: use prefetched value in mas_wr_store_type() maple_tree: clarify comments on mas_nomem() maple_tree: drop MAPLE_ALLOC_SLOTS maple_tree: drop dead code from mas_extend_spanning_null() maple_tree: documentation fix maple_tree: add write lock checking with lockdep sequence numbers ...
2026-08-24mm/swap: move swap_ops into file systems for file system-based swapChristoph Hellwig
Currently swap to and from file systems goes through two indirect calls between the swap ops and the swap_rw method. Reduce this by directly providing the swap_ops from the file system. For this refactor swap_fs_submit into a swap_fs_prepare_rw helper that initializes the iov_iter on the callers stack so that file systems can call it directly, and use that to initialize file system specific ops in the NFS and SMB clients, which then get passed to swap_fs_activate. Link: https://lore.kernel.org/20260723054622.3460249-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Chris Li <chrisl@kernel.org> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Kairui Song <kasong@tencent.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Steve French <sfrench@samba.org> Cc: Usama Arif <usama.arif@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-20Merge tag 'ext4_for_linus-7.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: - Improve performance by allowing parallel DIO writes when we were previously being overly conservative when checking whether it was safe to avoid requiring an exclusive lock - Improve the performance of ext4_mb_prefetch() used by fallocate() by avoiding work when it is not needed - Remove the unnecessary custom end_io function ext4_end_buffer_io_sync() - Improve performance when performing an overwrite to an already uptodate folio - Clean up how we handle deallocating EA inodes to avoid a potential lock ordering issue when there is a failed mount while an EA inode is still being evicted - Use str_plural() instead of a custom macro - Avoid soft lockups or RCU stalls if there are many busy buffers (caused by heavy I/O) while checkpointing - Use scoped NOFS when starting a handle in nojournal mode - Align fields in handle structure to optimize setting and getting the h_type and h_line_no fields - Fix documentation of the meta_bg block group layout - Bug fixes: - Fix a potential out-of-bounds read in ext4_read_inline_dir() - Fix a potential deadlock when concurrent xattr operations are racing with each other when some of the xattrs are using the ea_inode feature - Fix a spurious warning with data=journal that can be triggered when writeback races with remounting the file system read-only - Fix a potential deadlock when EXT4_IOC_MIGRATE races with a file system freeze operation - Make sure all in-flight direct I/O operations are complete before falling back to buffered I/O - Handle IOCB_NOWAIT properly when performing a extending DAX write - Prevent potentially sleeping on a block allocation when IOCB_NOWAIT is set - Fix potential races when racing an inline data write with a page fault - Propagate errors when adding or removing extent ranges during a fast commit replay - Avoid trying to expand an inode's extra size when it is being evicted to avoid a number of corner case or deadlocks - Avoid spurious error when retrying inode extra size expansion - Fix corner cases where we underestimate the number of journal credits needed - Avoid hangs/crashes/WARNINGS caused by maliciously corrupted file systems - Don't issue spurious orphan clean message on RO file systems - Avoid leaving the file system in an inconsistent state after a crash when a WRITE_ZEROS in progress converting an unwritten extent to a written extent - Handle WRITE_ZEROS correctly when there are some partially dirtied regions in the page cache - Pass errors during zero-rage, truncate, or punch hole to the caller if ext4_get_block() fails - Wait for writeback to finish when triggered by zero-range or zero-range for those devices that require stable writes - If the reserved gid superblock field is set, set the reserved gid instead of the reserved uid * tag 'ext4_for_linus-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (56 commits) ext4: fix estimate extent index blocks in ext4_ext_index_trans_blocks() ext4: fix transaction overflow during writeback ext4: teach ext4_meta_trans_blocks() about number of allocated extents ext4: guard against NULL s_group_info in ext4_get_group_info ext4: fix spurious message about orphan cleanup on RO fs ext4: stop retrying saturated xattr cache entries ext4: don't enable DAX on new encrypted files ext4: protect WRITE_ZEROES written extents with orphan list ext4: export converted block count from ext4_convert_unwritten_extents() ext4: fix incorrect function call when initializing s_resgid ext4: validate EA inode i_nlink in ext4_xattr_inode_iget jbd2: align h_type and h_line_no in the handle structure on byte boundaries ext4: enable scoped NOFS when starting a handle in nojournal mode ext4: write back partial-zeroed edges in WRITE_ZEROES ext4: zero out whole block for clean edges in WRITE_ZEROES ext4: track partial-zero outcome per edge in ext4_zero_partial_blocks() ext4: clarify return semantics of ext4_load_tail_bh() ext4: move partial block zeroing earlier in ext4_zero_range() ext4: check return value of ext4_get_block() in ext4_load_tail_bh() ext4: skip tail block zeroing for inline data files ...
2026-08-17Merge tag 'vfs-7.3-rc1.sync' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs writeback updates from Christian Brauner: "This makes sync_inode_metadata() and writeback_single_inode() persist not only the inode but all metadata associated with it. A new .sync_inode_metadata superblock operation is called from __writeback_single_inode(). Alongside it a new I_METADATA_WRITEBACK state flag is added. Filesystems no longer need their own mmb_fsync() implementations and can just use simple_fsync(). All metadata is now written for IS_SYNC and IS_DIRSYNC inodes. Races where several fsyncs raced and mmb_sync() could return before all buffers were really persisted are fixed since I_SYNC now serializes properly. The I_METADATA_WRITEBACK scheme also fixes the case where a WB_SYNC_NONE writeback landing between write(2) and fsync(2) left fsync(2) failing to persist the inode. That problem is not specific to filesystems using the generic metadata bh tracking, and the ones that do not are left alone. ext2, udf, bfs, minix, fat and ext4 in nojournal mode have their data integrity writeout fixed and are converted. affs drops metadata bh tracking and mmb_fsync() is removed. A few other fixes came out of this: - a UAF in mark_buffer_write_io_error() - missed inode writeback when racing with __writeback_single_inode() - ext4 allocating the mapping_metadata_bhs struct on demand - three fat fixes: a lost inode update in do_msdos_rename() with DIRSYNC, inode buffer write errors not propagating out of fat_sync_inode_metadata() and directory entries not being persisted on fsync(2) of the root directory" * tag 'vfs-7.3-rc1.sync' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits) writeback: Export __inode_attach_wb() fat: Fix persisting directory entries on fsync(2) of the root directory fat: Propagate inode buffer write errors from fat_sync_inode_metadata() fat: Fix lost inode update in do_msdos_rename() with DIRSYNC vfs: Remove mmb_fsync() fat: Replace fat_sync_inode() with sync_inode_metadata() fat: Fix missed inode writeback during fsync(2) ext4: Fix data integrity writeout issues in nojournal mode minix: Fix data integrity writeout issues bfs: Fix data integrity writeout issues udf: Fold udf_update_inode() into udf_write_inode() udf: Use sync_inode_metadata() in udf_evict_inode() udf: Drop udf_sync_inode() udf: Use sync_inode_metadata() to writeout IS_SYNC inode udf: Fix data integrity writeout issues ext2: Fix data integrity writeout issues ext2: Avoid unnecessary inode buffer writeback for sync(2) ext2: Drop __ext2_write_inode() ext2: Fix lost inode updates for IS_SYNC inodes fs: Provide way for filesystem to wait for metadata writeback ...
2026-08-17Merge tag 'vfs-7.3-rc1.super' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs superblock updates from Christian Brauner: - Make it possible to share a block device between multiple filesystems. erofs can mount read-only blob devices shared between many superblocks, but because we only tracked a single superblock a freeze, thaw, removal or sync on such a device was never propagated to all the superblocks using it, and there was no way to find them. Add an efficient table to lookup all superblocks using a given block device. - A bunch of pre-existing fixes fell out of this work: A block-device freeze racing a btrfs device change could leave the whole filesystem stuck frozen. A bdev_freeze() issued by "dmsetup suspend" or an LVM snapshot resolves that holder to freeze the filesystem. and bdev_thaw() resolves it again to thaw. A freeze landing while btrfs is adding, removing or replacing a device freezes the filesystem. The membership change then drops that link. So the matching thaw could no longer find the superblock. Forbid freezing a device for the duration of a membership change, modelled on deny_write_access()/allow_write_access(). * tag 'vfs-7.3-rc1.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits) super: fix dying superblock warning messages block: reject block device inodes with i_rdev == 0 in lookup_bdev() selftests/filesystems: add ustat() coverage fs: look up the superblock via the device table in user_get_super() super: make fs_holder_ops private f2fs: open via dedicated fs bdev helpers erofs: open via dedicated fs bdev helpers fs: tolerate per-superblock freeze errors on shared devices fs: look up superblocks via the device table in fs_holder_ops ext4: open via dedicated fs bdev helpers btrfs: open via dedicated fs bdev helpers xfs: port to fs_bdev_file_open_by_path() fs: add dedicated block device open helpers for filesystems fs: maintain a global device-to-superblock table ocfs2: don't reset s_dev on dismount ext4: use anonymous devices for KUnit test superblocks fs, block: move blk_mode_t and fop_flags_t into <linux/types.h> super: take lock after last reference count super: convert s_count to refcount_t s_passive btrfs: deny freezing devices undergoing a replace ...
2026-08-17Merge tag 'vfs-7.3-rc1.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Bigger cleanups: - The lockref dead-count handling is tidied up. The open-coded check for a count below zero as the dead marker relies on information the caller should not have. - make put_mnt_ns() leave mounts connected. Destroying a mount namespace disconnected its mounts from their mount points. So a file descriptor still open on the parent of a mount point could be used to peek under it. Locked mounts were already kept connected to prevent exactly that. But a mount is only locked when its tree is copied across a user namespace boundary. So a mount namespace set up by a privileged component had no locked mounts and its mounts were disconnected. Passing UMOUNT_CONNECTED keeps every mount connected and prevents that bug. - vfs_prepare_mode() passes S_IFDIR for directories. I meant to fix that ago but didn't get to it. So now someone finally did it. This kills the exception where the mode could be 0 when a directory was created whereas every other creation operation passed it explicitly already. - move long delayed work for ufs, jffs2, hfsplus, hfs and affs from the per-cpu system_long_wq to the new unbound system_dfl_long_wq. None of that work relies on per-cpu state and the work item is enqueued with queue_delayed_work() whose timer is global anyway. So it may as well benefit from scheduler task placement. Smaller fixes and cleanups: - unlock_buffer() and journal_end_buffer_io_sync() use clear_and_wake_up_bit() - the pipe page pools are unified into a single per-pipe pool and the extra wake_up(rd_wait) is limited to EPOLLET consumers - eventpoll now computes its timer slack lazily in ep_poll() - shrink_dcache_for_umount() keeps making progress on busy roots - excess xarray nodes are freed in clear_inode() - romfs detects hard link cycles - the user path of nested backing files is fixed - pidfd holds exec_update_lock around the namespace ioctl - non-memcg-aware nr_cached_objects is skipped during memcg slab shrink - iomap_write_iter() always returns status - mangle_path() is renamed to seq_mangle_path() - inode timestamp accessors are annotated - new regression test for pipe->poll_usage. - a few documentation, kernel-doc and selftest fixes" * tag 'vfs-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (67 commits) selftests/namespaces: Fix racy pipe handshake in timens and pidns_separate selftests/epoll: add a regression test for pipe->poll_usage pipe: only enable the extra wake_up(rd_wait) for EPOLLET consumers pidfd: hold exec_update_lock around namespace ioctl fs: fix user path of nested backing files fs: remove stale inode_insert5() kernel-doc parameter fs: fix switch/case indentation in sysfs() syscall fs: document semantics of kstat::{uid,gid} fields dcache: keep shrink_dcache_for_umount() making progress on busy roots seq_file: rename mangle_path to seq_mangle_path nstree: add/fix struct ns_id_req kernel-doc member fields dcache: use lockref routines for dead count checks lockref: tidy up dead count handling initramfs: fix typo in reserve_initrd_mem comment fs/pipe: unify the page pools into a single per-pipe pool fs: annotate inode timestamp accessors eventpoll: compute timer slack lazily in ep_poll() selftests/filesystems: add mntns cleanup test put_mnt_ns(): leave mounts connected affs: Move long delayed work on system_dfl_long_wq ...
2026-08-17Merge tag 'vfs-7.3-rc1.lookup' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs lookup updates from Christian Brauner: "This refactors lookup_open() and adds vfs_lookup_open() for nfsd. mnt_want_write() and parent locking are moved into lookup_open() itself. audit_inode_child() is also now called in lookup_open() on failure. That is the calling convention in vfs_create() and vfs_mkdir(), but lookup_open() made no such call when atomic_open() should have created a file and did not. And neither did the regular ->create() path fwiw. This also contains work to remove the unneeded excl argument from the ->create() inode op" * tag 'vfs-7.3-rc1.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs/namei.c: fix coding style in atomic_open() and lookup_open() fs/namei.c: fix kerneldoc of atomic_open() and vfs_lookup_open() fs/namei.c: update stale comments in lookup_open() Remove excl arg to ->create inode_operation fs/namei.c: update kerneldoc of atomic_open() vfs: call audit_inode_child() in lookup_open() on failure vfs: move create error && negative dentry case in lookup_open() up VFS: add vfs_lookup_open() for nfsd VFS: move delegated_inode retry loop into lookup_open() VFS: move mnt_want_write() and locking into lookup_open()
2026-07-31Remove excl arg to ->create inode_operationNeilBrown
The only time that 'false' is passed as the 'excl' arg to the ->create inode_operation is in lookup_open() when ->atomic_open is not provided by the parent directory. *all* directory inode_operations which do not have ->atomic_open completely ignore the 'excl' arg. Therefore we don't need the 'excl' arg. Those few ->create operations which pay attention to the arg are only ever called with a value of 'true'. We remove that arg and change all ->create operations to behave as those thhe arg were 'true'. Signed-off-by: NeilBrown <neil@brown.name> Link: https://patch.msgid.link/178290671516.27465.15984496764174914338@noble.neil.brown.name Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-31fs: annotate inode timestamp accessorsYu Peng
syzbot reported a KCSAN race between fill_mg_cmtime() and inode_set_ctime_to_ts() on inode->i_ctime_{sec,nsec}. stat/getattr can sample inode timestamps while update paths store new values concurrently, so KCSAN can report benign races on these fields. Annotate the timestamp accessors with READ_ONCE()/WRITE_ONCE(), and use the ctime accessor for the remaining ctime loads. This avoids the KCSAN reports without changing timestamp semantics. Fixes: 4e40eff0b573 ("fs: add infrastructure for multigrain timestamps") Reported-by: syzbot+8b3bd9f8a06658479d4a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8b3bd9f8a06658479d4a Signed-off-by: Yu Peng <pengyu@kylinos.cn> Link: https://patch.msgid.link/20260708080232.2564807-1-pengyu@kylinos.cn Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-27fs: Provide way for filesystem to wait for metadata writebackJan Kara
Currently, inode and in general metadata writeback is handled in a lazy manner. When inode is dirty, __writeback_single_inode() calls .write_inode method which for lots of filesystems just copies inode metadata into the underlying block buffer. Writeback of other metadata associated with the inode (as well as buffers underlying inodes) is usually handled completely separately and implicitely during writeback of block device inode. This is good for efficiency of WB_SYNC_NONE writeback or sync(2). However it becomes problematic for situations where we want to make sure inode and its metadata is really persistent on disk. fsync(2) is the most pronounced example of this and thus we have grown a special file operation and various helper functions to assist with this task. However fsync(2) is not the only case, For example directories with DIRSYNC flag need similar functionality and current use of sync_inode_metadata() for this task in filesystems generally misses writeout of necessary metadata. Furthermore even fsync(2) handling as implemented by simple_fsync() or similar helpers is racy and can fail to properly persist the inode. The problem is that WB_SYNC_NONE writeback can copy inode metadata into underlying buffer and clean inode dirty bits. Following fsync(2) will see inode is clean and will fail to make sure underlying buffer is written out. When multiple fsync(2) calls race, there's also another type of race involving mmb_fsync(). There the problem is buffers already submitted to the disk are no longer tracked in the mmb list and so racing mmb_sync() can return before all of the IO completes. Provide a new inode state bit I_METADATA_WRITEBACK tracking whether writeback of inode related metadata may be needed for successful data integrity sync and if this bit is set __writeback_single_inode() for data integrity writeback will call new superblock operation .sync_inode_metadata whose task is to make sure all metadata associated with the inode (including the inode itself) is properly persisted. This will allow filesystems to address the data integrity issues described above and at the same time somewhat simplify our fsync implementations. Issues with racing fsync(2) calls will be addressed by synchronization on I_SYNC inode state which is set while calling .sync_inode_metadata, issues with missed inode buffer writeback are fixed by filesystems looking up corresponding buffer head and writing it out if needed. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260727104923.3828017-25-jack@suse.cz Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-22fs: add iput_if_not_last() helperYun Zhou
Add a helper that drops an inode reference only if the caller does not hold the last one. Returns true if the reference was dropped, false otherwise. This is useful for filesystems that need to release inode references in contexts where triggering final iput (and thus eviction) would be unsafe due to lock ordering constraints. The caller can check the return value and defer the final iput to a safe context. Unlike iput_not_last() which BUG_ON's if called with the last ref, this variant is designed to be called speculatively. Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Suggested-by: Jan Kara <jack@suse.cz> Suggested-by: Mateusz Guzik <mjguzik@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christian Brauner (Amutable) <brauner@kernel.org> Tested-by: syzbot@syzkaller.appspotmail.com Link: https://patch.msgid.link/20260710030851.2791589-2-yun.zhou@windriver.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-01mm: do file ownership checks with the proper mount idmapPedro Falcato
Ever since idmapped mounts were introduced, inode ownership checks (for side-channel protection) in mincore() and madvise(MADV_PAGEOUT) were done against the nop_mnt_idmap, which completely ignores the file's mount's idmap. This results in odd edgecases like: 1) mount/bind-mount with an idmap userA:userB:1 2) userB runs an owner_or_capable() check on file that is owned by userA on-disk/in-memory, but owned by userB after idmap translation 3) owner_or_capable() mysteriously fails as the correct idmap wasn't supplied In the case of mincore/madvise MADV_PAGEOUT, this is usually benign, because file_permission(file, MAY_WRITE) will probably succeed, as it uses the proper idmap internally, but it does not need to be the case on e.g a 0444 file where even the owner itself doesn't have permissions to write to it. Since this is clearly not trivial to get right, introduce a file_owner_or_capable() that can carry the correct semantics, and switch the various users in mm to it. The issue was found by manual code inspection & an off-list discussion with Jan Kara. Link: https://lore.kernel.org/20260625153853.913949-1-pfalcato@suse.de Fixes: 9caccd41541a ("fs: introduce MOUNT_ATTR_IDMAP") Signed-off-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christian Brauner (Amutable) <brauner@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-06-29fs, block: move blk_mode_t and fop_flags_t into <linux/types.h>Christian Brauner
blk_mode_t and fop_flags_t are both plain 'unsigned int __bitwise' flag typedefs, exactly like the gfp_t, slab_flags_t and fmode_t that already live in <linux/types.h>. Move them there so they are available everywhere without having to drag in a subsystem header. Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260616-work-super-bdev_holder_global-v2-4-7df6b864028e@kernel.org Tested-by: syzbot@syzkaller.appspotmail.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-23Merge tag 'mm-stable-2026-06-23-08-55' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - "khugepaged: add mTHP collapse support" (Nico Pache) Provide khugepaged with the capability to collapse anonymous memory regions to mTHPs - "Remove CONFIG_READ_ONLY_THP_FOR_FS and enable file THP for writable files" (Zi Yan) Remove the READ_ONLY_THP_FOR_FS check in file_thp_enabled(), so that khugepaged and MADV_COLLAPSE can run on filesystems with PMD THP pagecache support even without READ_ONLY_THP_FOR_FS enabled - "make MM selftests more CI friendly" (Mike Rapoport) General fixes and cleanups to the MM selftests. Also move more MM selftests under the kselftest framework, making them more amenable to ongoing CI testing - "selftests/mm: fix failures and robustness improvements" and "selftests/mm: assorted fixes for hmm-tests" (Sayali Patil) Fix several issues in MM selftests which were revealed by powerpc 64k pagesize * tag 'mm-stable-2026-06-23-08-55' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (118 commits) Revert "mm: limit filemap_fault readahead to VMA boundaries" mm/vmscan: pass NULL to trace vmscan node reclaim mm: use mapping_mapped to simplify the code selftests/mm: fix exclusive_cow test fork() handling selftests/mm: remove hardcoded THP sizing assumptions in hmm tests selftests/mm: allow PUD-level entries in compound testcase of hmm tests mm/gup_test: reject wrapped user ranges mm/page_frag: reject invalid CPUs in page_frag_test mm/damon/core: always put unsuccessfully committed target pids mm: page_isolation: avoid unsafe folio reads while scanning compound pages mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show() selftests: mm: fix and speedup "droppable" test mm: merge writeout into pageout MAINTAINERS: add Hao Ge as reviewer for codetag and alloc_tag selftests/mm: clarify alternate unmapping in compaction_test selftests/mm: move hwpoison setup into run_test() and silence modprobe output for memory-failure category selftests/mm: skip uffd-stress test when nr_pages_per_cpu is zero selftests/mm: skip uffd-wp-mremap if UFFD write-protect is unsupported selftests/mm: ensure destination is hugetlb-backed in hugetlb-mremap selftest/mm: register existing mapping with userfaultfd in hugetlb-mremap ...
2026-06-21fs: remove nr_thps from struct address_spaceZi Yan
filemap_nr_thps*() are removed, the related field, address_space->nr_thps, is no longer needed. Remove it. This shrinks struct address_space by 8 bytes on 64-bit systems which may increase the number of inodes we can cache. Link: https://lore.kernel.org/20260517135416.1434539-8-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Nico Pache <npache@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-06-15Merge tag 'vfs-7.2-rc1.procfs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull procfs updates from Christian Brauner: - Revamp fs/filesystems.c The file was a mess with a hand-rolled linked list in desperate need of a cleanup. The filesystems list is now RCU-ified, /proc files can be marked permanent from outside fs/proc/, and the string emitted when reading /proc/filesystems is pre-generated and cached instead of pointer-chasing and printfing entry by entry on every read. The file is read frequently because libselinux reads it and is linked into numerous frequently used programs (even ones you would not suspect, like sed!). Scalability also improves since reference maintenance on open/close is bypassed. open+read+close cycle single-threaded (ops/s): before: 442732 after: 1063462 (+140%) open+read+close cycle with 20 processes (ops/s): before: 606177 after: 3300576 (+444%) A follow-up patch adds missing unlocks in some corner cases and tidies things up. - Relax the mount visibility check for subset=pid mounts When procfs is mounted with subset=pid, all static files become unavailable and only the dynamic pid information is accessible. In that case there is no point in imposing the full mount visibility restrictions on the mounter - everything that can be hidden in procfs is already inaccessible. These restrictions prevented procfs from being mounted inside rootless containers since almost all container implementations overmount parts of procfs to hide certain directories. As part of this /proc/self/net is only shown in subset=pid mounts for CAP_NET_ADMIN, reconfiguring subset=pid is rejected, the SB_I_USERNS_VISIBLE superblock flag is replaced with an FS_USERNS_MOUNT_RESTRICTED filesystem flag, fully visible mounts are recorded in a list, and the mount restrictions are finally documented. - Protect ptrace_may_access() with exec_update_lock in procfs Most uses of ptrace_may_access() in procfs should hold exec_update_lock to avoid TOCTOU issues with concurrent privileged execve() (like setuid binary execution). This fixes the easy cases - the owner and visibility checks and the FD link permission checks - with the gnarlier ones to follow later. * tag 'vfs-7.2-rc1.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: fix ups and tidy ups to /proc/filesystems caching proc: protect ptrace_may_access() with exec_update_lock (FD links) proc: protect ptrace_may_access() with exec_update_lock (part 1) docs: proc: add documentation about mount restrictions proc: handle subset=pid separately in userns visibility checks proc: prevent reconfiguring subset=pid proc: subset=pid: Show /proc/self/net only for CAP_NET_ADMIN fs: cache the string generated by reading /proc/filesystems sysfs: remove trivial sysfs_get_tree() wrapper fs: RCU-ify filesystems list fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED proc: allow to mark /proc files permanent outside of fs/proc/ namespace: record fully visible mounts in list