git: 27006229f7a4 - main - vinvalbuf: do not panic if we were unable to flush dirty buffers

[Konstantin Belousov]

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=27006229f7a40a18a61a0e8fd270bc583326b690

commit 27006229f7a40a18a61a0e8fd270bc583326b690
Author:     Konstantin Belousov <kib at FreeBSD.org>
AuthorDate: 2021-05-30 16:52:42 +0000
Commit:     Konstantin Belousov <kib at FreeBSD.org>
CommitDate: 2021-05-30 22:20:53 +0000

    vinvalbuf: do not panic if we were unable to flush dirty buffers
    
    Return EBUSY instead and let caller to handle the issue.
    
    For vgone()/vnode reclamation, caller first does vinvalbuf(V_SAVE),
    which return EBUSY in case dirty buffers where not flushed. Then caller
    calls vinvalbuf(0) due to non-zero return, which gets rid of all dirty
    buffers without dependencies.
    
    PR:     238565
    Reviewed by:    asomers, mckusick
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D30555
---
 sys/kern/vfs_subr.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 7c9604457aef..ad0f1c2a0c7c 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -2032,13 +2032,11 @@ bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
 			} while (error == ERELOOKUP);
 			if (error != 0)
 				return (error);
-			/*
-			 * XXX We could save a lock/unlock if this was only
-			 * enabled under INVARIANTS
-			 */
 			BO_LOCK(bo);
-			if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
-				panic("vinvalbuf: dirty bufs");
+			if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) {
+				BO_UNLOCK(bo);
+				return (EBUSY);
+			}
 		}
 	}
 	/*