From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Mon, 9 Feb 2009 18:46:13 +0000 (-0800)
Subject: HAMMER VFS: Correct a ref count leak in the recent I/O invalidation work
X-Git-Tag: v2.2.0~7^2~1
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/4983f1f6fa80b8035dd5fac7d32c4e470fb5766a

HAMMER VFS: Correct a ref count leak in the recent I/O invalidation work

Correct a ref count leak in the recent I/O invalidation work.  This could
lead to permanently referenced hammer_buffers and prevent reservations
from terminating.

Reported-by: Michael Neumann <mneumann@ntecs.de>
---

diff --git a/sys/vfs/hammer/hammer_ondisk.c b/sys/vfs/hammer/hammer_ondisk.c
index 44e4e00ce9..711fe65a81 100644
--- a/sys/vfs/hammer/hammer_ondisk.c
+++ b/sys/vfs/hammer/hammer_ondisk.c
@@ -736,8 +736,10 @@ hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
 				   base_offset);
 		if (buffer) {
 			error = hammer_ref_buffer(buffer);
-			if (error == 0 && buffer->io.lock.refs != 1)
+			if (error == 0 && buffer->io.lock.refs != 1) {
 				error = EAGAIN;
+				hammer_rel_buffer(buffer, 0);
+			}
 			if (error == 0) {
 				KKASSERT(buffer->zone2_offset == zone2_offset);
 				hammer_io_clear_modify(&buffer->io, 1);
@@ -752,7 +754,7 @@ hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
 		if (error) {
 			ret_error = error;
 			if (report_conflicts || (hammer_debug_general & 0x8000))
-				kprintf("hammer_del_buffers: unable to invalidate %016llx rep=%d\n", base_offset, report_conflicts);
+				kprintf("hammer_del_buffers: unable to invalidate %016llx buffer=%p rep=%d\n", base_offset, buffer, report_conflicts);
 		}
 		base_offset += HAMMER_BUFSIZE;
 		zone2_offset += HAMMER_BUFSIZE;