Merge tag 'for-6.8-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - zoned mode fixes:
     - fix slowdown when writing large file sequentially by looking up
       block groups with enough space faster
     - locking fixes when activating a zone

 - new mount API fixes:
     - preserve mount options for a ro/rw mount of the same subvolume

 - scrub fixes:
     - fix use-after-free in case the chunk length is not aligned to
       64K, this does not happen normally but has been reported on
       images converted from ext4
     - similar alignment check was missing with raid-stripe-tree

 - subvolume deletion fixes:
     - prevent calling ioctl on already deleted subvolume
     - properly track flag tracking a deleted subvolume

 - in subpage mode, fix decompression of an inline extent (zlib, lzo,
   zstd)

 - fix crash when starting writeback on a folio, after integration with
   recent MM changes this needs to be started conditionally

 - reject unknown flags in defrag ioctl

 - error handling, API fixes, minor warning fixes

* tag 'for-6.8-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: scrub: limit RST scrub to chunk boundary
  btrfs: scrub: avoid use-after-free when chunk length is not 64K aligned
  btrfs: don't unconditionally call folio_start_writeback in subpage
  btrfs: use the original mount's mount options for the legacy reconfigure
  btrfs: don't warn if discard range is not aligned to sector
  btrfs: tree-checker: fix inline ref size in error messages
  btrfs: zstd: fix and simplify the inline extent decompression
  btrfs: lzo: fix and simplify the inline extent decompression
  btrfs: zlib: fix and simplify the inline extent decompression
  btrfs: defrag: reject unknown flags of btrfs_ioctl_defrag_range_args
  btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot of subvolume being deleted
  btrfs: don't abort filesystem when attempting to snapshot deleted subvolume
  btrfs: zoned: fix lock ordering in btrfs_zone_activate()
  btrfs: fix unbalanced unlock of mapping_tree_lock
  btrfs: ref-verify: free ref cache before clearing mount opt
  btrfs: fix kvcalloc() arguments order in btrfs_ioctl_send()
  btrfs: zoned: optimize hint byte for zoned allocator
  btrfs: zoned: factor out prepare_allocation_zoned()

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 896acfda1789..101f786963d4 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1457,6 +1457,14 @@ static int btrfs_reconfigure(struct fs_context *fc)
 
 	btrfs_info_to_ctx(fs_info, &old_ctx);
 
+	/*
+	 * This is our "bind mount" trick, we don't want to allow the user to do
+	 * anything other than mount a different ro/rw and a different subvol,
+	 * all of the mount options should be maintained.
+	 */
+	if (mount_reconfigure)
+		ctx->mount_opt = old_ctx.mount_opt;
+
 	sync_filesystem(sb);
 	set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);