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-rw-r--r--.mailmap1
-rw-r--r--Documentation/process/embargoed-hardware-issues.rst1
-rw-r--r--fs/smb/server/connection.c2
-rw-r--r--fs/smb/server/connection.h1
-rw-r--r--fs/smb/server/smb2pdu.c74
-rw-r--r--fs/smb/server/transport_rdma.c10
-rw-r--r--fs/smb/server/transport_tcp.c3
-rw-r--r--fs/smb/server/vfs.c5
-rw-r--r--fs/smb/server/vfs_cache.h1
-rw-r--r--kernel/cgroup/legacy_freezer.c3
-rw-r--r--rust/bindings/bindings_helper.h1
-rw-r--r--rust/helpers/completion.c8
-rw-r--r--rust/helpers/helpers.c1
-rw-r--r--rust/kernel/devres.rs60
-rw-r--r--rust/kernel/revocable.rs18
-rw-r--r--rust/kernel/sync.rs2
-rw-r--r--rust/kernel/sync/completion.rs112
17 files changed, 256 insertions, 47 deletions
diff --git a/.mailmap b/.mailmap
index 1999905a9c7e..fee7681100a8 100644
--- a/.mailmap
+++ b/.mailmap
@@ -197,6 +197,7 @@ Daniel Borkmann <daniel@iogearbox.net> <daniel.borkmann@tik.ee.ethz.ch>
Daniel Borkmann <daniel@iogearbox.net> <dborkmann@redhat.com>
Daniel Borkmann <daniel@iogearbox.net> <dborkman@redhat.com>
Daniel Borkmann <daniel@iogearbox.net> <dxchgb@gmail.com>
+Danilo Krummrich <dakr@kernel.org> <dakr@redhat.com>
David Brownell <david-b@pacbell.net>
David Collins <quic_collinsd@quicinc.com> <collinsd@codeaurora.org>
David Heidelberg <david@ixit.cz> <d.okias@gmail.com>
diff --git a/Documentation/process/embargoed-hardware-issues.rst b/Documentation/process/embargoed-hardware-issues.rst
index da6bf0f6d01e..34e00848e0da 100644
--- a/Documentation/process/embargoed-hardware-issues.rst
+++ b/Documentation/process/embargoed-hardware-issues.rst
@@ -290,6 +290,7 @@ an involved disclosed party. The current ambassadors list:
AMD Tom Lendacky <thomas.lendacky@amd.com>
Ampere Darren Hart <darren@os.amperecomputing.com>
ARM Catalin Marinas <catalin.marinas@arm.com>
+ IBM Power Madhavan Srinivasan <maddy@linux.ibm.com>
IBM Z Christian Borntraeger <borntraeger@de.ibm.com>
Intel Tony Luck <tony.luck@intel.com>
Qualcomm Trilok Soni <quic_tsoni@quicinc.com>
diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c
index 83764c230e9d..3f04a2977ba8 100644
--- a/fs/smb/server/connection.c
+++ b/fs/smb/server/connection.c
@@ -40,7 +40,7 @@ void ksmbd_conn_free(struct ksmbd_conn *conn)
kvfree(conn->request_buf);
kfree(conn->preauth_info);
if (atomic_dec_and_test(&conn->refcnt)) {
- ksmbd_free_transport(conn->transport);
+ conn->transport->ops->free_transport(conn->transport);
kfree(conn);
}
}
diff --git a/fs/smb/server/connection.h b/fs/smb/server/connection.h
index 6efed923bd68..dd3e0e3f7bf0 100644
--- a/fs/smb/server/connection.h
+++ b/fs/smb/server/connection.h
@@ -133,6 +133,7 @@ struct ksmbd_transport_ops {
void *buf, unsigned int len,
struct smb2_buffer_desc_v1 *desc,
unsigned int desc_len);
+ void (*free_transport)(struct ksmbd_transport *kt);
};
struct ksmbd_transport {
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index 1a308171b599..fafa86273f12 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -1607,17 +1607,18 @@ static int krb5_authenticate(struct ksmbd_work *work,
out_len = work->response_sz -
(le16_to_cpu(rsp->SecurityBufferOffset) + 4);
- /* Check previous session */
- prev_sess_id = le64_to_cpu(req->PreviousSessionId);
- if (prev_sess_id && prev_sess_id != sess->id)
- destroy_previous_session(conn, sess->user, prev_sess_id);
-
retval = ksmbd_krb5_authenticate(sess, in_blob, in_len,
out_blob, &out_len);
if (retval) {
ksmbd_debug(SMB, "krb5 authentication failed\n");
return -EINVAL;
}
+
+ /* Check previous session */
+ prev_sess_id = le64_to_cpu(req->PreviousSessionId);
+ if (prev_sess_id && prev_sess_id != sess->id)
+ destroy_previous_session(conn, sess->user, prev_sess_id);
+
rsp->SecurityBufferLength = cpu_to_le16(out_len);
if ((conn->sign || server_conf.enforced_signing) ||
@@ -4871,8 +4872,13 @@ static int get_file_standard_info(struct smb2_query_info_rsp *rsp,
sinfo = (struct smb2_file_standard_info *)rsp->Buffer;
delete_pending = ksmbd_inode_pending_delete(fp);
- sinfo->AllocationSize = cpu_to_le64(stat.blocks << 9);
- sinfo->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+ if (ksmbd_stream_fd(fp) == false) {
+ sinfo->AllocationSize = cpu_to_le64(stat.blocks << 9);
+ sinfo->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+ } else {
+ sinfo->AllocationSize = cpu_to_le64(fp->stream.size);
+ sinfo->EndOfFile = cpu_to_le64(fp->stream.size);
+ }
sinfo->NumberOfLinks = cpu_to_le32(get_nlink(&stat) - delete_pending);
sinfo->DeletePending = delete_pending;
sinfo->Directory = S_ISDIR(stat.mode) ? 1 : 0;
@@ -4935,9 +4941,14 @@ static int get_file_all_info(struct ksmbd_work *work,
file_info->ChangeTime = cpu_to_le64(time);
file_info->Attributes = fp->f_ci->m_fattr;
file_info->Pad1 = 0;
- file_info->AllocationSize =
- cpu_to_le64(stat.blocks << 9);
- file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+ if (ksmbd_stream_fd(fp) == false) {
+ file_info->AllocationSize =
+ cpu_to_le64(stat.blocks << 9);
+ file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+ } else {
+ file_info->AllocationSize = cpu_to_le64(fp->stream.size);
+ file_info->EndOfFile = cpu_to_le64(fp->stream.size);
+ }
file_info->NumberOfLinks =
cpu_to_le32(get_nlink(&stat) - delete_pending);
file_info->DeletePending = delete_pending;
@@ -4946,7 +4957,10 @@ static int get_file_all_info(struct ksmbd_work *work,
file_info->IndexNumber = cpu_to_le64(stat.ino);
file_info->EASize = 0;
file_info->AccessFlags = fp->daccess;
- file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+ if (ksmbd_stream_fd(fp) == false)
+ file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+ else
+ file_info->CurrentByteOffset = cpu_to_le64(fp->stream.pos);
file_info->Mode = fp->coption;
file_info->AlignmentRequirement = 0;
conv_len = smbConvertToUTF16((__le16 *)file_info->FileName, filename,
@@ -5134,8 +5148,13 @@ static int get_file_network_open_info(struct smb2_query_info_rsp *rsp,
time = ksmbd_UnixTimeToNT(stat.ctime);
file_info->ChangeTime = cpu_to_le64(time);
file_info->Attributes = fp->f_ci->m_fattr;
- file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
- file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+ if (ksmbd_stream_fd(fp) == false) {
+ file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
+ file_info->EndOfFile = S_ISDIR(stat.mode) ? 0 : cpu_to_le64(stat.size);
+ } else {
+ file_info->AllocationSize = cpu_to_le64(fp->stream.size);
+ file_info->EndOfFile = cpu_to_le64(fp->stream.size);
+ }
file_info->Reserved = cpu_to_le32(0);
rsp->OutputBufferLength =
cpu_to_le32(sizeof(struct smb2_file_ntwrk_info));
@@ -5158,7 +5177,11 @@ static void get_file_position_info(struct smb2_query_info_rsp *rsp,
struct smb2_file_pos_info *file_info;
file_info = (struct smb2_file_pos_info *)rsp->Buffer;
- file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+ if (ksmbd_stream_fd(fp) == false)
+ file_info->CurrentByteOffset = cpu_to_le64(fp->filp->f_pos);
+ else
+ file_info->CurrentByteOffset = cpu_to_le64(fp->stream.pos);
+
rsp->OutputBufferLength =
cpu_to_le32(sizeof(struct smb2_file_pos_info));
}
@@ -5247,8 +5270,13 @@ static int find_file_posix_info(struct smb2_query_info_rsp *rsp,
file_info->ChangeTime = cpu_to_le64(time);
file_info->DosAttributes = fp->f_ci->m_fattr;
file_info->Inode = cpu_to_le64(stat.ino);
- file_info->EndOfFile = cpu_to_le64(stat.size);
- file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
+ if (ksmbd_stream_fd(fp) == false) {
+ file_info->EndOfFile = cpu_to_le64(stat.size);
+ file_info->AllocationSize = cpu_to_le64(stat.blocks << 9);
+ } else {
+ file_info->EndOfFile = cpu_to_le64(fp->stream.size);
+ file_info->AllocationSize = cpu_to_le64(fp->stream.size);
+ }
file_info->HardLinks = cpu_to_le32(stat.nlink);
file_info->Mode = cpu_to_le32(stat.mode & 0777);
switch (stat.mode & S_IFMT) {
@@ -6190,6 +6218,9 @@ static int set_file_allocation_info(struct ksmbd_work *work,
if (!(fp->daccess & FILE_WRITE_DATA_LE))
return -EACCES;
+ if (ksmbd_stream_fd(fp) == true)
+ return 0;
+
rc = vfs_getattr(&fp->filp->f_path, &stat, STATX_BASIC_STATS,
AT_STATX_SYNC_AS_STAT);
if (rc)
@@ -6248,7 +6279,8 @@ static int set_end_of_file_info(struct ksmbd_work *work, struct ksmbd_file *fp,
* truncate of some filesystem like FAT32 fill zero data in
* truncated range.
*/
- if (inode->i_sb->s_magic != MSDOS_SUPER_MAGIC) {
+ if (inode->i_sb->s_magic != MSDOS_SUPER_MAGIC &&
+ ksmbd_stream_fd(fp) == false) {
ksmbd_debug(SMB, "truncated to newsize %lld\n", newsize);
rc = ksmbd_vfs_truncate(work, fp, newsize);
if (rc) {
@@ -6321,7 +6353,13 @@ static int set_file_position_info(struct ksmbd_file *fp,
return -EINVAL;
}
- fp->filp->f_pos = current_byte_offset;
+ if (ksmbd_stream_fd(fp) == false)
+ fp->filp->f_pos = current_byte_offset;
+ else {
+ if (current_byte_offset > XATTR_SIZE_MAX)
+ current_byte_offset = XATTR_SIZE_MAX;
+ fp->stream.pos = current_byte_offset;
+ }
return 0;
}
diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c
index 4998df04ab95..64a428a06ace 100644
--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -159,7 +159,8 @@ struct smb_direct_transport {
};
#define KSMBD_TRANS(t) ((struct ksmbd_transport *)&((t)->transport))
-
+#define SMBD_TRANS(t) ((struct smb_direct_transport *)container_of(t, \
+ struct smb_direct_transport, transport))
enum {
SMB_DIRECT_MSG_NEGOTIATE_REQ = 0,
SMB_DIRECT_MSG_DATA_TRANSFER
@@ -410,6 +411,11 @@ err:
return NULL;
}
+static void smb_direct_free_transport(struct ksmbd_transport *kt)
+{
+ kfree(SMBD_TRANS(kt));
+}
+
static void free_transport(struct smb_direct_transport *t)
{
struct smb_direct_recvmsg *recvmsg;
@@ -455,7 +461,6 @@ static void free_transport(struct smb_direct_transport *t)
smb_direct_destroy_pools(t);
ksmbd_conn_free(KSMBD_TRANS(t)->conn);
- kfree(t);
}
static struct smb_direct_sendmsg
@@ -2281,4 +2286,5 @@ static const struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops = {
.read = smb_direct_read,
.rdma_read = smb_direct_rdma_read,
.rdma_write = smb_direct_rdma_write,
+ .free_transport = smb_direct_free_transport,
};
diff --git a/fs/smb/server/transport_tcp.c b/fs/smb/server/transport_tcp.c
index abedf510899a..4e9f98db9ff4 100644
--- a/fs/smb/server/transport_tcp.c
+++ b/fs/smb/server/transport_tcp.c
@@ -93,7 +93,7 @@ static struct tcp_transport *alloc_transport(struct socket *client_sk)
return t;
}
-void ksmbd_free_transport(struct ksmbd_transport *kt)
+static void ksmbd_tcp_free_transport(struct ksmbd_transport *kt)
{
struct tcp_transport *t = TCP_TRANS(kt);
@@ -656,4 +656,5 @@ static const struct ksmbd_transport_ops ksmbd_tcp_transport_ops = {
.read = ksmbd_tcp_read,
.writev = ksmbd_tcp_writev,
.disconnect = ksmbd_tcp_disconnect,
+ .free_transport = ksmbd_tcp_free_transport,
};
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index ba45e809555a..0f3aad12e495 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -293,6 +293,7 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos,
if (v_len - *pos < count)
count = v_len - *pos;
+ fp->stream.pos = v_len;
memcpy(buf, &stream_buf[*pos], count);
@@ -456,8 +457,8 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
true);
if (err < 0)
goto out;
-
- fp->filp->f_pos = *pos;
+ else
+ fp->stream.pos = size;
err = 0;
out:
kvfree(stream_buf);
diff --git a/fs/smb/server/vfs_cache.h b/fs/smb/server/vfs_cache.h
index 5bbb179736c2..0708155b5caf 100644
--- a/fs/smb/server/vfs_cache.h
+++ b/fs/smb/server/vfs_cache.h
@@ -44,6 +44,7 @@ struct ksmbd_lock {
struct stream {
char *name;
ssize_t size;
+ loff_t pos;
};
struct ksmbd_inode {
diff --git a/kernel/cgroup/legacy_freezer.c b/kernel/cgroup/legacy_freezer.c
index 039d1eb2f215..507b8f19a262 100644
--- a/kernel/cgroup/legacy_freezer.c
+++ b/kernel/cgroup/legacy_freezer.c
@@ -188,13 +188,12 @@ static void freezer_attach(struct cgroup_taskset *tset)
if (!(freezer->state & CGROUP_FREEZING)) {
__thaw_task(task);
} else {
- freeze_task(task);
-
/* clear FROZEN and propagate upwards */
while (freezer && (freezer->state & CGROUP_FROZEN)) {
freezer->state &= ~CGROUP_FROZEN;
freezer = parent_freezer(freezer);
}
+ freeze_task(task);
}
}
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index bc494745f67b..8cbb660e2ec2 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -39,6 +39,7 @@
#include <linux/blk_types.h>
#include <linux/blkdev.h>
#include <linux/clk.h>
+#include <linux/completion.h>
#include <linux/configfs.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
diff --git a/rust/helpers/completion.c b/rust/helpers/completion.c
new file mode 100644
index 000000000000..b2443262a2ae
--- /dev/null
+++ b/rust/helpers/completion.c
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/completion.h>
+
+void rust_helper_init_completion(struct completion *x)
+{
+ init_completion(x);
+}
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 16fa9bca5949..b15b3cddad4e 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -13,6 +13,7 @@
#include "build_assert.c"
#include "build_bug.c"
#include "clk.c"
+#include "completion.c"
#include "cpu.c"
#include "cpufreq.c"
#include "cpumask.c"
diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs
index 0f79a2ec9474..57502534d985 100644
--- a/rust/kernel/devres.rs
+++ b/rust/kernel/devres.rs
@@ -12,26 +12,28 @@ use crate::{
error::{Error, Result},
ffi::c_void,
prelude::*,
- revocable::Revocable,
- sync::Arc,
+ revocable::{Revocable, RevocableGuard},
+ sync::{rcu, Arc, Completion},
types::ARef,
};
-use core::ops::Deref;
-
#[pin_data]
struct DevresInner<T> {
dev: ARef<Device>,
callback: unsafe extern "C" fn(*mut c_void),
#[pin]
data: Revocable<T>,
+ #[pin]
+ revoke: Completion,
}
/// This abstraction is meant to be used by subsystems to containerize [`Device`] bound resources to
/// manage their lifetime.
///
/// [`Device`] bound resources should be freed when either the resource goes out of scope or the
-/// [`Device`] is unbound respectively, depending on what happens first.
+/// [`Device`] is unbound respectively, depending on what happens first. In any case, it is always
+/// guaranteed that revoking the device resource is completed before the corresponding [`Device`]
+/// is unbound.
///
/// To achieve that [`Devres`] registers a devres callback on creation, which is called once the
/// [`Device`] is unbound, revoking access to the encapsulated resource (see also [`Revocable`]).
@@ -102,6 +104,7 @@ impl<T> DevresInner<T> {
dev: dev.into(),
callback: Self::devres_callback,
data <- Revocable::new(data),
+ revoke <- Completion::new(),
}),
flags,
)?;
@@ -130,26 +133,28 @@ impl<T> DevresInner<T> {
self as _
}
- fn remove_action(this: &Arc<Self>) {
+ fn remove_action(this: &Arc<Self>) -> bool {
// SAFETY:
// - `self.inner.dev` is a valid `Device`,
// - the `action` and `data` pointers are the exact same ones as given to devm_add_action()
// previously,
// - `self` is always valid, even if the action has been released already.
- let ret = unsafe {
+ let success = unsafe {
bindings::devm_remove_action_nowarn(
this.dev.as_raw(),
Some(this.callback),
this.as_ptr() as _,
)
- };
+ } == 0;
- if ret == 0 {
+ if success {
// SAFETY: We leaked an `Arc` reference to devm_add_action() in `DevresInner::new`; if
// devm_remove_action_nowarn() was successful we can (and have to) claim back ownership
// of this reference.
let _ = unsafe { Arc::from_raw(this.as_ptr()) };
}
+
+ success
}
#[allow(clippy::missing_safety_doc)]
@@ -161,7 +166,12 @@ impl<T> DevresInner<T> {
// `DevresInner::new`.
let inner = unsafe { Arc::from_raw(ptr) };
- inner.data.revoke();
+ if !inner.data.revoke() {
+ // If `revoke()` returns false, it means that `Devres::drop` already started revoking
+ // `inner.data` for us. Hence we have to wait until `Devres::drop()` signals that it
+ // completed revoking `inner.data`.
+ inner.revoke.wait_for_completion();
+ }
}
}
@@ -218,20 +228,36 @@ impl<T> Devres<T> {
// SAFETY: `dev` being the same device as the device this `Devres` has been created for
// proves that `self.0.data` hasn't been revoked and is guaranteed to not be revoked as
// long as `dev` lives; `dev` lives at least as long as `self`.
- Ok(unsafe { self.deref().access() })
+ Ok(unsafe { self.0.data.access() })
}
-}
-impl<T> Deref for Devres<T> {
- type Target = Revocable<T>;
+ /// [`Devres`] accessor for [`Revocable::try_access`].
+ pub fn try_access(&self) -> Option<RevocableGuard<'_, T>> {
+ self.0.data.try_access()
+ }
+
+ /// [`Devres`] accessor for [`Revocable::try_access_with`].
+ pub fn try_access_with<R, F: FnOnce(&T) -> R>(&self, f: F) -> Option<R> {
+ self.0.data.try_access_with(f)
+ }
- fn deref(&self) -> &Self::Target {
- &self.0.data
+ /// [`Devres`] accessor for [`Revocable::try_access_with_guard`].
+ pub fn try_access_with_guard<'a>(&'a self, guard: &'a rcu::Guard) -> Option<&'a T> {
+ self.0.data.try_access_with_guard(guard)
}
}
impl<T> Drop for Devres<T> {
fn drop(&mut self) {
- DevresInner::remove_action(&self.0);
+ // SAFETY: When `drop` runs, it is guaranteed that nobody is accessing the revocable data
+ // anymore, hence it is safe not to wait for the grace period to finish.
+ if unsafe { self.0.data.revoke_nosync() } {
+ // We revoked `self.0.data` before the devres action did, hence try to remove it.
+ if !DevresInner::remove_action(&self.0) {
+ // We could not remove the devres action, which means that it now runs concurrently,
+ // hence signal that `self.0.data` has been revoked successfully.
+ self.0.revoke.complete_all();
+ }
+ }
}
}
diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
index db4aa46bb121..06a3cdfce344 100644
--- a/rust/kernel/revocable.rs
+++ b/rust/kernel/revocable.rs
@@ -154,8 +154,10 @@ impl<T> Revocable<T> {
/// # Safety
///
/// Callers must ensure that there are no more concurrent users of the revocable object.
- unsafe fn revoke_internal<const SYNC: bool>(&self) {
- if self.is_available.swap(false, Ordering::Relaxed) {
+ unsafe fn revoke_internal<const SYNC: bool>(&self) -> bool {
+ let revoke = self.is_available.swap(false, Ordering::Relaxed);
+
+ if revoke {
if SYNC {
// SAFETY: Just an FFI call, there are no further requirements.
unsafe { bindings::synchronize_rcu() };
@@ -165,6 +167,8 @@ impl<T> Revocable<T> {
// `compare_exchange` above that takes `is_available` from `true` to `false`.
unsafe { drop_in_place(self.data.get()) };
}
+
+ revoke
}
/// Revokes access to and drops the wrapped object.
@@ -172,10 +176,13 @@ impl<T> Revocable<T> {
/// Access to the object is revoked immediately to new callers of [`Revocable::try_access`],
/// expecting that there are no concurrent users of the object.
///
+ /// Returns `true` if `&self` has been revoked with this call, `false` if it was revoked
+ /// already.
+ ///
/// # Safety
///
/// Callers must ensure that there are no more concurrent users of the revocable object.
- pub unsafe fn revoke_nosync(&self) {
+ pub unsafe fn revoke_nosync(&self) -> bool {
// SAFETY: By the safety requirement of this function, the caller ensures that nobody is
// accessing the data anymore and hence we don't have to wait for the grace period to
// finish.
@@ -189,7 +196,10 @@ impl<T> Revocable<T> {
/// If there are concurrent users of the object (i.e., ones that called
/// [`Revocable::try_access`] beforehand and still haven't dropped the returned guard), this
/// function waits for the concurrent access to complete before dropping the wrapped object.
- pub fn revoke(&self) {
+ ///
+ /// Returns `true` if `&self` has been revoked with this call, `false` if it was revoked
+ /// already.
+ pub fn revoke(&self) -> bool {
// SAFETY: By passing `true` we ask `revoke_internal` to wait for the grace period to
// finish.
unsafe { self.revoke_internal::<true>() }
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index 36a719015583..c23a12639924 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -10,6 +10,7 @@ use crate::types::Opaque;
use pin_init;
mod arc;
+pub mod completion;
mod condvar;
pub mod lock;
mod locked_by;
@@ -17,6 +18,7 @@ pub mod poll;
pub mod rcu;
pub use arc::{Arc, ArcBorrow, UniqueArc};
+pub use completion::Completion;
pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult};
pub use lock::global::{global_lock, GlobalGuard, GlobalLock, GlobalLockBackend, GlobalLockedBy};
pub use lock::mutex::{new_mutex, Mutex, MutexGuard};
diff --git a/rust/kernel/sync/completion.rs b/rust/kernel/sync/completion.rs
new file mode 100644
index 000000000000..c50012a940a3
--- /dev/null
+++ b/rust/kernel/sync/completion.rs
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Completion support.
+//!
+//! Reference: <https://docs.kernel.org/scheduler/completion.html>
+//!
+//! C header: [`include/linux/completion.h`](srctree/include/linux/completion.h)
+
+use crate::{bindings, prelude::*, types::Opaque};
+
+/// Synchronization primitive to signal when a certain task has been completed.
+///
+/// The [`Completion`] synchronization primitive signals when a certain task has been completed by
+/// waking up other tasks that have been queued up to wait for the [`Completion`] to be completed.
+///
+/// # Examples
+///
+/// ```
+/// use kernel::sync::{Arc, Completion};
+/// use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
+///
+/// #[pin_data]
+/// struct MyTask {
+/// #[pin]
+/// work: Work<MyTask>,
+/// #[pin]
+/// done: Completion,
+/// }
+///
+/// impl_has_work! {
+/// impl HasWork<Self> for MyTask { self.work }
+/// }
+///
+/// impl MyTask {
+/// fn new() -> Result<Arc<Self>> {
+/// let this = Arc::pin_init(pin_init!(MyTask {
+/// work <- new_work!("MyTask::work"),
+/// done <- Completion::new(),
+/// }), GFP_KERNEL)?;
+///
+/// let _ = workqueue::system().enqueue(this.clone());
+///
+/// Ok(this)
+/// }
+///
+/// fn wait_for_completion(&self) {
+/// self.done.wait_for_completion();
+///
+/// pr_info!("Completion: task complete\n");
+/// }
+/// }
+///
+/// impl WorkItem for MyTask {
+/// type Pointer = Arc<MyTask>;
+///
+/// fn run(this: Arc<MyTask>) {
+/// // process this task
+/// this.done.complete_all();
+/// }
+/// }
+///
+/// let task = MyTask::new()?;
+/// task.wait_for_completion();
+/// # Ok::<(), Error>(())
+/// ```
+#[pin_data]
+pub struct Completion {
+ #[pin]
+ inner: Opaque<bindings::completion>,
+}
+
+// SAFETY: `Completion` is safe to be send to any task.
+unsafe impl Send for Completion {}
+
+// SAFETY: `Completion` is safe to be accessed concurrently.
+unsafe impl Sync for Completion {}
+
+impl Completion {
+ /// Create an initializer for a new [`Completion`].
+ pub fn new() -> impl PinInit<Self> {
+ pin_init!(Self {
+ inner <- Opaque::ffi_init(|slot: *mut bindings::completion| {
+ // SAFETY: `slot` is a valid pointer to an uninitialized `struct completion`.
+ unsafe { bindings::init_completion(slot) };
+ }),
+ })
+ }
+
+ fn as_raw(&self) -> *mut bindings::completion {
+ self.inner.get()
+ }
+
+ /// Signal all tasks waiting on this completion.
+ ///
+ /// This method wakes up all tasks waiting on this completion; after this operation the
+ /// completion is permanently done, i.e. signals all current and future waiters.
+ pub fn complete_all(&self) {
+ // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`.
+ unsafe { bindings::complete_all(self.as_raw()) };
+ }
+
+ /// Wait for completion of a task.
+ ///
+ /// This method waits for the completion of a task; it is not interruptible and there is no
+ /// timeout.
+ ///
+ /// See also [`Completion::complete_all`].
+ pub fn wait_for_completion(&self) {
+ // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`.
+ unsafe { bindings::wait_for_completion(self.as_raw()) };
+ }
+}
generated by cgit (git 2.34.1) at 2025-06-19 10:18:32 +0000