From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/btrfs/volumes.c | 44 +++++++++++++++++++++++++++++++++++++++-----
1 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/kernel/fs/btrfs/volumes.c b/kernel/fs/btrfs/volumes.c
index 9191bbb..389493e 100644
--- a/kernel/fs/btrfs/volumes.c
+++ b/kernel/fs/btrfs/volumes.c
@@ -381,6 +381,7 @@
static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device;
+
WARN_ON(fs_devices->opened);
while (!list_empty(&fs_devices->devices)) {
device = list_entry(fs_devices->devices.next,
@@ -715,6 +716,14 @@
blkdev_put(bdev, flags);
return -EINVAL;
+}
+
+u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb)
+{
+ bool has_metadata_uuid = (btrfs_super_incompat_flags(sb) &
+ BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
+
+ return has_metadata_uuid ? sb->metadata_uuid : sb->fsid;
}
/*
@@ -1227,8 +1236,21 @@
mutex_lock(&uuid_mutex);
close_fs_devices(fs_devices);
- if (!fs_devices->opened)
+ if (!fs_devices->opened) {
list_splice_init(&fs_devices->seed_list, &list);
+
+ /*
+ * If the struct btrfs_fs_devices is not assembled with any
+ * other device, it can be re-initialized during the next mount
+ * without the needing device-scan step. Therefore, it can be
+ * fully freed.
+ */
+ if (fs_devices->num_devices == 1) {
+ list_del(&fs_devices->fs_list);
+ free_fs_devices(fs_devices);
+ }
+ }
+
list_for_each_entry_safe(fs_devices, tmp, &list, seed_list) {
close_fs_devices(fs_devices);
@@ -1396,8 +1418,17 @@
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
bytenr = btrfs_sb_offset(0);
- flags |= FMODE_EXCL;
+ /*
+ * Avoid using flag |= FMODE_EXCL here, as the systemd-udev may
+ * initiate the device scan which may race with the user's mount
+ * or mkfs command, resulting in failure.
+ * Since the device scan is solely for reading purposes, there is
+ * no need for FMODE_EXCL. Additionally, the devices are read again
+ * during the mount process. It is ok to get some inconsistent
+ * values temporarily, as the device paths of the fsid are the only
+ * required information for assembling the volume.
+ */
bdev = blkdev_get_by_path(path, flags, holder);
if (IS_ERR(bdev))
return ERR_CAST(bdev);
@@ -1579,7 +1610,7 @@
goto out;
}
- while (1) {
+ while (search_start < search_end) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
@@ -1601,6 +1632,9 @@
if (key.type != BTRFS_DEV_EXTENT_KEY)
goto next;
+
+ if (key.offset > search_end)
+ break;
if (key.offset > search_start) {
hole_size = key.offset - search_start;
@@ -1662,6 +1696,7 @@
else
ret = 0;
+ ASSERT(max_hole_start + max_hole_size <= search_end);
out:
btrfs_free_path(path);
*start = max_hole_start;
@@ -4432,8 +4467,7 @@
}
}
- BUG_ON(fs_info->balance_ctl ||
- test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+ ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
atomic_dec(&fs_info->balance_cancel_req);
mutex_unlock(&fs_info->balance_mutex);
return 0;
--
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