This is a note to let you know that I've just added the patch titled
dlm: fix user space lock decision to copy lvb
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dlm-fix-user-space-lock-decision-to-copy-lvb.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cb3f168729a818b95bac6a73ec5f4854627a0df4
Author: Alexander Aring <aahringo@xxxxxxxxxx>
Date: Thu Mar 28 11:48:33 2024 -0400
dlm: fix user space lock decision to copy lvb
[ Upstream commit ad191e0eeebf64a60ca2d16ca01a223d2b1dd25e ]
This patch fixes the copy lvb decision for user space lock requests.
Checking dlm_lvb_operations is done earlier, where granted/requested
lock modes are available to use in the matrix.
The decision had been moved to the wrong location, where granted mode
and requested mode where the same, which causes the dlm_lvb_operations
matix to produce the wrong copy decision. For PW or EX requests, the
caller could get invalid lvb data.
Fixes: 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks")
Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
Signed-off-by: David Teigland <teigland@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 1f2f70a1b824e..decedc4ee15f6 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -12,6 +12,7 @@
#include <trace/events/dlm.h>
#include "dlm_internal.h"
+#include "lvb_table.h"
#include "memory.h"
#include "lock.h"
#include "user.h"
@@ -42,6 +43,7 @@ int dlm_enqueue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
struct dlm_ls *ls = lkb->lkb_resource->res_ls;
int rv = DLM_ENQUEUE_CALLBACK_SUCCESS;
struct dlm_callback *cb;
+ int copy_lvb = 0;
int prev_mode;
if (flags & DLM_CB_BAST) {
@@ -73,6 +75,17 @@ int dlm_enqueue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
goto out;
}
}
+ } else if (flags & DLM_CB_CAST) {
+ if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
+ if (lkb->lkb_last_cast)
+ prev_mode = lkb->lkb_last_cb->mode;
+ else
+ prev_mode = -1;
+
+ if (!status && lkb->lkb_lksb->sb_lvbptr &&
+ dlm_lvb_operations[prev_mode + 1][mode + 1])
+ copy_lvb = 1;
+ }
}
cb = dlm_allocate_cb();
@@ -85,6 +98,7 @@ int dlm_enqueue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
cb->mode = mode;
cb->sb_status = status;
cb->sb_flags = (sbflags & 0x000000FF);
+ cb->copy_lvb = copy_lvb;
kref_init(&cb->ref);
if (!test_and_set_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags))
rv = DLM_ENQUEUE_CALLBACK_NEED_SCHED;
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index dfc444dad3298..511d0b984f580 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -222,6 +222,7 @@ struct dlm_callback {
int sb_status; /* copy to lksb status */
uint8_t sb_flags; /* copy to lksb flags */
int8_t mode; /* rq mode of bast, gr mode of cast */
+ int copy_lvb;
struct list_head list;
struct kref ref;
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 9f9b68448830e..12a483deeef5e 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -21,7 +21,6 @@
#include "dlm_internal.h"
#include "lockspace.h"
#include "lock.h"
-#include "lvb_table.h"
#include "user.h"
#include "ast.h"
#include "config.h"
@@ -806,8 +805,7 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count,
struct dlm_lkb *lkb;
DECLARE_WAITQUEUE(wait, current);
struct dlm_callback *cb;
- int rv, ret, copy_lvb = 0;
- int old_mode, new_mode;
+ int rv, ret;
if (count == sizeof(struct dlm_device_version)) {
rv = copy_version_to_user(buf, count);
@@ -864,9 +862,6 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count,
lkb = list_first_entry(&proc->asts, struct dlm_lkb, lkb_cb_list);
- /* rem_lkb_callback sets a new lkb_last_cast */
- old_mode = lkb->lkb_last_cast->mode;
-
rv = dlm_dequeue_lkb_callback(lkb, &cb);
switch (rv) {
case DLM_DEQUEUE_CALLBACK_EMPTY:
@@ -895,12 +890,6 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count,
if (cb->flags & DLM_CB_BAST) {
trace_dlm_bast(lkb->lkb_resource->res_ls, lkb, cb->mode);
} else if (cb->flags & DLM_CB_CAST) {
- new_mode = cb->mode;
-
- if (!cb->sb_status && lkb->lkb_lksb->sb_lvbptr &&
- dlm_lvb_operations[old_mode + 1][new_mode + 1])
- copy_lvb = 1;
-
lkb->lkb_lksb->sb_status = cb->sb_status;
lkb->lkb_lksb->sb_flags = cb->sb_flags;
trace_dlm_ast(lkb->lkb_resource->res_ls, lkb);
@@ -908,7 +897,7 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count,
ret = copy_result_to_user(lkb->lkb_ua,
test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
- cb->flags, cb->mode, copy_lvb, buf, count);
+ cb->flags, cb->mode, cb->copy_lvb, buf, count);
kref_put(&cb->ref, dlm_release_callback);
