Date: Tue, 27 Jul 2021 16:59:00 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 10db1896495b - main - fifofs: fifo vnode might be relocked before VOP_OPEN() is called Message-ID: <202107271659.16RGx0Sf083540@gitrepo.freebsd.org>
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The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=10db1896495b744aa5b039dd4ef1973b7a339379 commit 10db1896495b744aa5b039dd4ef1973b7a339379 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2021-07-22 10:27:43 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2021-07-27 16:58:47 +0000 fifofs: fifo vnode might be relocked before VOP_OPEN() is called Handle it in fifo_close by checking for v_fifoinfo == NULL Reported and tested by: pho Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D31310 --- sys/fs/fifofs/fifo_vnops.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/sys/fs/fifofs/fifo_vnops.c b/sys/fs/fifofs/fifo_vnops.c index d2a51de84fba..861f1b40a744 100644 --- a/sys/fs/fifofs/fifo_vnops.c +++ b/sys/fs/fifofs/fifo_vnops.c @@ -282,9 +282,21 @@ fifo_close(ap) struct pipe *cpipe; vp = ap->a_vp; + ASSERT_VOP_ELOCKED(vp, "fifo_close"); fip = vp->v_fifoinfo; + + /* + * During open, it is possible that the fifo vnode is relocked + * after the vnode is instantiated but before VOP_OPEN() is + * done. For instance, vn_open_vnode() might need to upgrade + * vnode lock, or ffs_vput_pair() needs to unlock vp to sync + * dvp. In this case, reclaim can observe us with v_fifoinfo + * equal to NULL. + */ + if (fip == NULL) + return (0); + cpipe = fip->fi_pipe; - ASSERT_VOP_ELOCKED(vp, "fifo_close"); if (ap->a_fflag & FREAD) { fip->fi_readers--; if (fip->fi_readers == 0) {
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