kernel/linux.git/fs/ceph, branch v7.2-rc1

Merge tag 'ceph-for-7.2-rc1' of https://github.com/ceph/ceph-client

2026-06-26T23:15:53+00:00

Pull ceph updates from Ilya Dryomov: "This adds support for manual client session reset in CephFS, allowing operators to get out of tricky livelock situations involving caps and file locks without evicting the problematic client instance on the MDS side or rebooting the client node both of which can be disruptive" * tag 'ceph-for-7.2-rc1' of https://github.com/ceph/ceph-client: ceph: add manual reset debugfs control and tracepoints ceph: add client reset state machine and session teardown ceph: add diagnostic timeout loop to wait_caps_flush() ceph: harden send_mds_reconnect and handle active-MDS peer reset ceph: use proper endian conversion for flock_len in reconnect ceph: convert inode flags to named bit positions and atomic bitops rbd: switch to dynamic root device

ceph: add manual reset debugfs control and tracepoints

2026-06-22T20:45:05+00:00

Add the debugfs and trace plumbing used to trigger and observe manual client reset. The reset interface exposes a trigger file for operator-initiated reset and a status file for tracking the most recent run. The tracepoints record scheduling, completion, and blocked caller behavior so reset progress can be diagnosed from the client side. debugfs layout under /sys/kernel/debug/ceph//reset/: trigger - write to initiate a manual reset status - read to see the most recent reset result The reset directory is cleaned up via debugfs_remove_recursive() on the parent, so individual file dentries are not stored. Tracepoints: ceph_client_reset_schedule - reset queued ceph_client_reset_complete - reset finished (success or failure) ceph_client_reset_blocked - caller blocked waiting for reset ceph_client_reset_unblocked - caller unblocked after reset All tracepoints use a null-safe access for monc.auth->global_id to guard against early-init or late-teardown edge cases. Signed-off-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov

ceph: add client reset state machine and session teardown

2026-06-22T20:45:00+00:00

Add the client-side reset state machine, request gating, and manual session teardown implementation. Manual reset is an operator-triggered escape hatch for client/MDS stalemates in which caps, locks, or unsafe metadata state stop making forward progress. The reset blocks new metadata work, attempts a bounded best-effort drain of dirty client state while sessions are still alive, and finally asks the MDS to close sessions before tearing local session state down directly. The reset state machine tracks four phases: IDLE -> QUIESCING -> DRAINING -> TEARDOWN -> IDLE. QUIESCING is set synchronously by schedule_reset() before the workqueue item is dispatched, so that new metadata requests and file-lock acquisitions are gated immediately -- even before the work function begins running. All non-IDLE phases block callers on blocked_wq, preventing races with session teardown. The drain phase flushes mdlog state, dirty caps, and pending cap releases for a bounded interval. State that still cannot make progress within that interval is discarded during teardown, which is the point of the reset: break the stalemate and allow fresh sessions to rebuild clean state. The session teardown follows the established check_new_map() forced-close pattern: unregister sessions under mdsc->mutex, then clean up caps and requests under s->s_mutex. Reconnect is not attempted because the MDS only accepts reconnects during its own RECONNECT phase after restart, not from an active client. Blocked callers are released when reset completes and observe the final result via -EAGAIN (reset failed) or 0 (success). Internal work-function errors such as -ENOMEM are not propagated to unrelated callers like open() or flock(); the detailed error remains in debugfs and tracepoints. The work function checks st->shutdown before each phase transition (DRAINING, TEARDOWN) so that a concurrent ceph_mdsc_destroy() is not overwritten. If destroy already took ownership, the work function releases session references and returns without touching the state. The timeout calculation for blocked-request waiters uses max_t() to prevent jiffies underflow when the deadline has already passed. The close-grace sleep before teardown is a best-effort nudge to let queued REQUEST_CLOSE messages egress; it is not a correctness requirement since the MDS still has session_autoclose as a fallback. The destroy path marks reset as failed and wakes blocked waiters before cancel_work_sync() so unmount does not stall. Signed-off-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov

ceph: add diagnostic timeout loop to wait_caps_flush()

2026-06-22T20:44:56+00:00

Convert wait_caps_flush() from a silent indefinite wait into a diagnostic wait loop that periodically dumps pending cap flush state. The underlying wait semantics remain intact: callers still wait until the requested cap flushes complete. The difference is that long stalls now produce actionable diagnostics instead of looking like a silent hang. CEPH_CAP_FLUSH_MAX_DUMP_ENTRIES limits the number of entries emitted per diagnostic dump, and CEPH_CAP_FLUSH_MAX_DUMP_ITERS limits the number of timed diagnostic dumps before the wait continues silently. When more entries exist than the per-dump limit, a truncation count is reported. When the dump iteration limit is reached, a final suppression message is emitted so the transition to silence is explicit. The diagnostic dump collects flush entry data under cap_dirty_lock into a bounded on-stack array, then prints after releasing the lock. This avoids holding the spinlock across printk calls. A null cf->ci on the global flush list indicates a bug since all cap_flush entries are initialized with a valid ci before being added. Signal this with WARN_ON_ONCE while still printing enough context for debugging. READ_ONCE is used for the i_last_cap_flush_ack field, which is read outside the inode lock domain. Flush tids are monotonically increasing and acks are processed in order under i_ceph_lock, so the latest ack tid is always the most recently written value. Add a ci pointer to struct ceph_cap_flush so that the diagnostic dump can identify which inode each pending flush belongs to. The new i_last_cap_flush_ack field tracks the latest acknowledged flush tid per inode for diagnostic correlation. This improves reset-drain observability and is also useful for existing sync and writeback troubleshooting paths. Signed-off-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov

ceph: harden send_mds_reconnect and handle active-MDS peer reset

2026-06-22T20:44:50+00:00

Change send_mds_reconnect() to return an error code so callers can detect and report reconnect failures instead of silently ignoring them. Add early bailout checks for sessions that are already closed, rejected, or unregistered, which avoids sending reconnect messages for sessions that can no longer be recovered. The early -ESTALE and -ENOENT bailouts use a separate fail_return label that skips the pr_err_client diagnostic, since these codes indicate expected concurrent-teardown races rather than genuine reconnect build failures. Move the "reconnect start" log after the early-bailout checks so it only appears for sessions that actually proceed with reconnect. Save the prior session state before transitioning to RECONNECTING, and restore it in the failure path. Without this, a transient build or encoding failure (-ENOMEM, -ENOSPC) strands the session in RECONNECTING indefinitely because check_new_map() only retries sessions in RESTARTING state. Rewrite mds_peer_reset() to handle the case where the MDS is past its RECONNECT phase (i.e. active). An active MDS rejects CLIENT_RECONNECT messages because it only accepts them during its own RECONNECT window after restart. Previously, the client would send a doomed reconnect that the MDS would reject or ignore. Now, the client tears the session down locally and lets new requests re-open a fresh session, which is the correct recovery for this scenario. The RECONNECTING state is handled on the same teardown path, since the MDS will reject reconnect attempts from an active client regardless of the session's local state. Add explicit cases for CLOSED and REJECTED session states in mds_peer_reset() since these are terminal states where a connection drop is expected behavior. The session teardown path in mds_peer_reset() follows the established drop-and-reacquire locking pattern from check_new_map(): take mdsc->mutex for session unregistration, release it, then take s->s_mutex separately for cleanup. This avoids introducing a new simultaneous lock nesting pattern. Log reconnect failures from check_new_map() and mds_peer_reset() at pr_warn level rather than pr_err, since return codes like -ESTALE (closed/rejected session) and -ENOENT (unregistered session) are expected during concurrent teardown. Log dropped messages for unregistered sessions via doutc() (dynamic debug) rather than pr_info, as post-reset message arrival is routine and does not warrant unconditional logging. Signed-off-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov

ceph: use proper endian conversion for flock_len in reconnect

2026-06-22T20:44:47+00:00

Replace the __force __le32 cast with cpu_to_le32() for the flock_len field in reconnect_caps_cb(). The old code used a type-system bypass to silence sparse; the new form uses the proper endian conversion macro. Also switch from a raw bitmask test against i_ceph_flags to test_bit() on the named CEPH_I_ERROR_FILELOCK_BIT, which is the correct accessor for the unsigned long flags field after the bit-position conversion. Remove the now-unused CEPH_I_ERROR_FILELOCK mask define since all callers use the _BIT form with test_bit/set_bit/clear_bit. Signed-off-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov

ceph: convert inode flags to named bit positions and atomic bitops

2026-06-22T20:44:42+00:00

Define named bit-position constants for all CEPH_I_* inode flags and derive the bitmask values from them. This gives every flag a named _BIT constant usable with the test_bit/set_bit/clear_bit family. The intentionally unused bit position 1 is documented inline. Convert all flag modifications to use atomic bitops (set_bit, clear_bit, test_and_clear_bit). The previous code mixed lockless atomic ops on some flags (ERROR_WRITE, ODIRECT) with non-atomic read-modify-write (|= / &= ~) on other flags sharing the same unsigned long. A concurrent non-atomic RMW can clobber an adjacent lockless atomic update -- for example, a lockless clear_bit(ERROR_WRITE) could be silently resurrected by a concurrent ci->i_ceph_flags |= CEPH_I_FLUSH under the spinlock. Using atomic bitops for all modifications eliminates this class of race entirely. Flags whose only users are now the _BIT form (ERROR_WRITE, ASYNC_CHECK_CAPS) have their old mask defines removed to document that callers must use the _BIT constant with the set_bit/test_bit family. ERROR_FILELOCK and SHUTDOWN retain their mask defines because they are still used via bitmask tests in lockless readers (ceph_inode_is_shutdown, reconnect_caps_cb). The direct assignment in ceph_finish_async_create() is converted from i_ceph_flags = CEPH_I_ASYNC_CREATE to set_bit(). This inode is I_NEW at this point -- still invisible to other threads and guaranteed to have zero flags from alloc_inode -- so either form is safe, but set_bit() keeps the conversion uniform. Signed-off-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov

Merge tag 'vfs-7.2-rc1.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-06-14T21:41:05+00:00

Pull openat2 updates from Christian Brauner: "Features: - Add O_EMPTYPATH to openat(2)/openat2(2). To get an operable file descriptor from an O_PATH file descriptor it is possible to use openat(fd, ".", O_DIRECTORY) for directories, but other file types require going through open("/proc//fd/") and thus depend on a functioning procfs. With O_EMPTYPATH an empty path string is accepted and LOOKUP_EMPTY is set at path resolution time, allowing to reopen the file behind the file descriptor directly. Selftests are included. - Add an OPENAT2_REGULAR flag for openat2(2) which refuses to open anything but regular files with the new EFTYPE error code. This implements the "ability to only open regular files" feature requested by userspace via uapi-group.org and protects services from being redirected to fifos, device nodes, and friends. All atomic_open implementations were audited for OPENAT2_REGULAR handling. Explicit checks were added to ceph, gfs2, nfs (v4), and cifs/smb - these are the filesystems whose atomic_open can encounter an existing non-regular file and would otherwise call finish_open() on it or return a misleading error code. The remaining implementations (9p, fuse, vboxsf, nfs v2/v3) only call finish_open() on freshly created files and use finish_no_open() for lookup hits, letting the VFS catch non-regular files via the do_open() safety net. Cleanups: - Migrate the openat2 selftests to the kselftest harness and move them under selftests/filesystems/. The tests were written in the early days of selftests' TAP support and the modern kselftest harness is much easier to follow and maintain. The contents of the tests are unchanged and the new emptypath tests are ported on top. - Make the LAST_XXX last-type constants private to fs/namei.c. The only user outside of fs/namei.c was ksmbd which only needs to know whether the last component is a regular one, so vfs_path_parent_lookup() now performs the LAST_NORM check internally. The ints are replaced with a dedicated enum last_type" * tag 'vfs-7.2-rc1.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: vfs: replace ints with enum last_type for LAST_XXX vfs: make LAST_XXX private to fs/namei.c selftests: openat2: port emptypath_test to kselftest harness kselftest/openat2: test for OPENAT2_REGULAR flag openat2: new OPENAT2_REGULAR flag support openat2: introduce EFTYPE error code selftest: add tests for O_EMPTYPATH vfs: add O_EMPTYPATH to openat(2)/openat2(2) selftests: openat2: migrate to kselftest harness selftests: openat2: switch from custom ARRAY_LEN to ARRAY_SIZE selftests: openat2: move helpers to header selftests: move openat2 tests to selftests/filesystems/

Merge tag 'vfs-7.2-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-06-14T21:14:23+00:00

Pull vfs inode updates from Christian Brauner: "This extends the lockless ->i_count handling. iput() could already decrement any value greater than one locklessly but acquiring a reference always required taking inode->i_lock. Now acquiring a reference is lockless as long as the count was already at least 1, i.e., only the 0->1 and 1->0 transitions take the lock. This avoids the lock for the common cases of nfs calling into the inode hash and btrfs using igrab(). Cleanup-wise icount_read_once() is added to line up with inode_state_read_once() and the open-coded ->i_count loads across the tree are converted, and ihold() is relocated and tidied up. On top of that some stale lock ordering annotations are retired from the inode hash code: iunique() no longer takes the hash lock since the inode hash became RCU-searchable and s_inode_list_lock is no longer taken under the hash lock either" * tag 'vfs-7.2-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: retire stale lock ordering annotations from inode hash fs: allow lockless ->i_count bumps as long as it does not transition 0->1 fs: relocate and tidy up ihold() fs: add icount_read_once() and stop open-coding ->i_count loads

openat2: new OPENAT2_REGULAR flag support

2026-05-21T13:33:47+00:00

This flag indicates the path should be opened if it's a regular file. This is useful to write secure programs that want to avoid being tricked into opening device nodes with special semantics while thinking they operate on regular files. This is a requested feature from the uapi-group[1]. The previously introduced EFTYPE error code is returned when the path doesn't refer to a regular file. For example, if openat2 is called on path /dev/null with OPENAT2_REGULAR in the flag param, it will return -EFTYPE. When used in combination with O_CREAT, either the regular file is created, or if the path already exists, it is opened if it's a regular file. Otherwise, -EFTYPE is returned. When OPENAT2_REGULAR is combined with O_DIRECTORY, -EINVAL is returned as it doesn't make sense to open a path that is both a directory and a regular file. The UAPI bit lives in the upper 32 bits of open_how::flags (((__u64)1 << 32)) so that open(2) and openat(2) -- whose @flags argument is a C int -- cannot physically express it. This is a structural guarantee, not a runtime mask: the bit is unrepresentable in 32 bits. Because the rest of the VFS open path narrows to 32 bits in several places (op->open_flag, f->f_flags, the unsigned open_flag argument of i_op->atomic_open()), build_open_flags() translates OPENAT2_REGULAR into a kernel-internal lower-32-bit carrier __O_REGULAR (bit 4, unused as an O_* on every architecture) before the assignment to op->open_flag. __O_REGULAR then rides through the existing channels exactly like __FMODE_EXEC. do_dentry_open() strips it so it cannot leak back to userspace via fcntl(F_GETFL). Four BUILD_BUG_ON_MSG() invariants in build_open_flags() prevent any future bit collision or accidental low-32 redefinition: - VALID_OPEN_FLAGS fits in 32 bits. - OPENAT2_REGULAR lives in the upper 32 bits. - OPENAT2_REGULAR does not alias any open()/openat() flag. - __O_REGULAR does not alias any user-visible flag. [1]: https://uapi-group.org/kernel-features/#ability-to-only-open-regular-files Christian Brauner says: Move OPENAT2_REGULAR to the upper 32 bits of open_how::flags with a kernel-internal __O_REGULAR carrier so that open(2)/openat(2) cannot encode the flag; add BUILD_BUG_ON_MSG() invariants and register __O_REGULAR in the fcntl_init() allocation-uniqueness BUILD_BUG_ON() (bit count 21 -> 22). Signed-off-by: Dorjoy Chowdhury Link: https://patch.msgid.link/20260328172314.45807-2-dorjoychy111@gmail.com Reviewed-by: Jeff Layton Reviewed-by: Aleksa Sarai Signed-off-by: Christian Brauner (Amutable)