nbd: NBD_CLEAR_SOCK races with buffered writes and triggers mark_buffer_dirty() warning

[blktests-ci]

Pull request for series with
subject: nbd: NBD_CLEAR_SOCK races with buffered writes and triggers mark_buffer_dirty() warning
version: 1
url: https://patchwork.kernel.org/project/linux-block/list/?series=1117579

[blktests-ci]

Upstream branch: 523fc0d
series: https://patchwork.kernel.org/project/linux-block/list/?series=1117579
version: 1

Pull request is NOT updated. Failed to apply https://patchwork.kernel.org/project/linux-block/list/?series=1117579
error message:

Cmd('git') failed due to: exit code(128)
  cmdline: git am --3way
  stdout: 'Applying: nbd: NBD_CLEAR_SOCK races with buffered writes and triggers mark_buffer_dirty() warning
Using index info to reconstruct a base tree...
M	fs/buffer.c
Falling back to patching base and 3-way merge...
Auto-merging fs/buffer.c
CONFLICT (content): Merge conflict in fs/buffer.c
Patch failed at 0001 nbd: NBD_CLEAR_SOCK races with buffered writes and triggers mark_buffer_dirty() warning
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".'
  stderr: 'error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch'

conflict:

diff --cc fs/buffer.c
index 9af5f061a1f8,d5937b193ed2..000000000000
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@@ -54,6 -57,47 +57,50 @@@
  
  #include "internal.h"
  
++<<<<<<< HEAD
++=======
+ static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
+ 			  enum rw_hint hint, struct writeback_control *wbc);
+ 
+ static unsigned int nbd_block_commit_delay_ms;
+ 
+ /*
+  * Parse the test-only delay that widens the block_commit_write() window for
+  * NBD buffer_heads.
+  */
+ static int __init nbd_block_commit_delay_setup(char *str)
+ {
+ 	if (kstrtouint(str, 0, &nbd_block_commit_delay_ms))
+ 		nbd_block_commit_delay_ms = 0;
+ 	return 1;
+ }
+ __setup("nbd_block_commit_delay_ms=", nbd_block_commit_delay_setup);
+ 
+ /* Return whether a buffer_head belongs to an NBD block device. */
+ static bool buffer_head_is_nbd(struct buffer_head *bh)
+ {
+ 	if (!bh->b_bdev)
+ 		return false;
+ 	return MAJOR(bh->b_bdev->bd_dev) == NBD_MAJOR;
+ }
+ 
+ /*
+  * Delay after BH_Uptodate is set but before mark_buffer_dirty() checks it, so
+  * NBD_CLEAR_SOCK has a larger window to complete an old writeback with IOERR.
+  */
+ static void nbd_block_commit_delay(struct buffer_head *bh)
+ {
+ 	unsigned int delay_ms = READ_ONCE(nbd_block_commit_delay_ms);
+ 
+ 	if (!delay_ms || !buffer_head_is_nbd(bh))
+ 		return;
+ 
+ 	pr_info_ratelimited("nbd-block-commit-delay: delaying %u ms for bh=%p b_state=0x%lx bdev=%pg\n",
+ 			    delay_ms, bh, bh->b_state, bh->b_bdev);
+ 	msleep(delay_ms);
+ }
+ 
++>>>>>>> nbd: NBD_CLEAR_SOCK races with buffered writes and triggers mark_buffer_dirty() warning
  #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)
  
  inline void touch_buffer(struct buffer_head *bh)