From: Franck Bui <fbui@suse.com>
Date: Thu, 25 Jan 2024 08:53:21 +0000 (+0100)
Subject: loop-util: drop unused .uevent_seqnum_not_before and .timestamp_not_before fields
X-Git-Tag: v256-rc1~1042
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ba1816dfe747199cd30c95476ec354240397f69;p=thirdparty%2Fsystemd.git

loop-util: drop unused .uevent_seqnum_not_before and .timestamp_not_before fields
---

diff --git a/src/shared/loop-util.c b/src/shared/loop-util.c
index 8434587286c..c6dfff43197 100644
--- a/src/shared/loop-util.c
+++ b/src/shared/loop-util.c
@@ -57,21 +57,6 @@ static int loop_is_bound(int fd) {
         return true; /* bound! */
 }
 
-static int get_current_uevent_seqnum(uint64_t *ret) {
-        _cleanup_free_ char *p = NULL;
-        int r;
-
-        r = read_full_virtual_file("/sys/kernel/uevent_seqnum", &p, NULL);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to read current uevent sequence number: %m");
-
-        r = safe_atou64(strstrip(p), ret);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to parse current uevent sequence number: %s", p);
-
-        return 0;
-}
-
 static int open_lock_fd(int primary_fd, int operation) {
         _cleanup_close_ int lock_fd = -EBADF;
 
@@ -266,8 +251,7 @@ static int loop_configure(
         _cleanup_(cleanup_clear_loop_close) int loop_with_fd = -EBADF; /* This must be declared before lock_fd. */
         _cleanup_close_ int fd = -EBADF, lock_fd = -EBADF;
         _cleanup_free_ char *node = NULL;
-        uint64_t diskseq = 0, seqnum = UINT64_MAX;
-        usec_t timestamp = USEC_INFINITY;
+        uint64_t diskseq = 0;
         dev_t devno;
         int r;
 
@@ -327,18 +311,6 @@ static int loop_configure(
                                               "Removed partitions on the loopback block device.");
 
         if (!loop_configure_broken) {
-                /* Acquire uevent seqnum immediately before attaching the loopback device. This allows
-                 * callers to ignore all uevents with a seqnum before this one, if they need to associate
-                 * uevent with this attachment. Doing so isn't race-free though, as uevents that happen in
-                 * the window between this reading of the seqnum, and the LOOP_CONFIGURE call might still be
-                 * mistaken as originating from our attachment, even though might be caused by an earlier
-                 * use. But doing this at least shortens the race window a bit. */
-                r = get_current_uevent_seqnum(&seqnum);
-                if (r < 0)
-                        return log_device_debug_errno(dev, r, "Failed to get the current uevent seqnum: %m");
-
-                timestamp = now(CLOCK_MONOTONIC);
-
                 if (ioctl(fd, LOOP_CONFIGURE, c) < 0) {
                         /* Do fallback only if LOOP_CONFIGURE is not supported, propagate all other
                          * errors. Note that the kernel is weird: non-existing ioctls currently return EINVAL
@@ -370,13 +342,6 @@ static int loop_configure(
         }
 
         if (loop_configure_broken) {
-                /* Let's read the seqnum again, to shorten the window. */
-                r = get_current_uevent_seqnum(&seqnum);
-                if (r < 0)
-                        return log_device_debug_errno(dev, r, "Failed to get the current uevent seqnum: %m");
-
-                timestamp = now(CLOCK_MONOTONIC);
-
                 if (ioctl(fd, LOOP_SET_FD, c->fd) < 0)
                         return log_device_debug_errno(dev, errno, "ioctl(LOOP_SET_FD) failed: %m");
 
@@ -423,8 +388,6 @@ static int loop_configure(
                 .devno = devno,
                 .dev = TAKE_PTR(dev),
                 .diskseq = diskseq,
-                .uevent_seqnum_not_before = seqnum,
-                .timestamp_not_before = timestamp,
                 .sector_size = c->block_size,
                 .device_size = device_size,
                 .created = true,
@@ -986,8 +949,6 @@ int loop_device_open(
                 .relinquished = true, /* It's not ours, don't try to destroy it when this object is freed */
                 .devno = devnum,
                 .diskseq = diskseq,
-                .uevent_seqnum_not_before = UINT64_MAX,
-                .timestamp_not_before = USEC_INFINITY,
                 .sector_size = sector_size,
                 .device_size = device_size,
                 .created = false,
diff --git a/src/shared/loop-util.h b/src/shared/loop-util.h
index 94357bba717..4f563172b6d 100644
--- a/src/shared/loop-util.h
+++ b/src/shared/loop-util.h
@@ -26,8 +26,6 @@ struct LoopDevice {
         dev_t backing_devno; /* The backing file's dev_t */
         ino_t backing_inode; /* The backing file's ino_t */
         uint64_t diskseq; /* Block device sequence number, monothonically incremented by the kernel on create/attach, or 0 if we don't know */
-        uint64_t uevent_seqnum_not_before; /* uevent sequm right before we attached the loopback device, or UINT64_MAX if we don't know */
-        usec_t timestamp_not_before; /* CLOCK_MONOTONIC timestamp taken immediately before attaching the loopback device, or USEC_INFINITY if we don't know */
         uint32_t sector_size;
         uint64_t device_size;
 };