Date: Sun, 6 Aug 2023 20:36:39 GMT From: Marius Strobl <marius@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 0096e445c55a - stable/13 - ffs: wait for trims earlier during unmount to avoid panic Message-ID: <202308062036.376Kadbo042916@gitrepo.freebsd.org>
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The branch stable/13 has been updated by marius: URL: https://cgit.FreeBSD.org/src/commit/?id=0096e445c55a4a882c213d91eaf33766e27439f4 commit 0096e445c55a4a882c213d91eaf33766e27439f4 Author: Chuck Silvers <chs@FreeBSD.org> AuthorDate: 2022-04-08 17:19:40 +0000 Commit: Marius Strobl <marius@FreeBSD.org> CommitDate: 2023-08-06 17:56:42 +0000 ffs: wait for trims earlier during unmount to avoid panic All softdep processing is supposed to be completed by softdep_flushfiles() and no more deps are supposed to be created after that, but if a pending trim completes after softdep_flushfiles() and before softdep_unmount() then the blkfree that is performed by ffs_blkfree_trim_task() will create a dep when none should exist, and if softdep_unmount() is called before that dep is freed then the kernel will panic. Prevent this by waiting for trims to complete earlier in the unmount process, in ffs_flushfiles(), so that any deps will be freed and any modified CG buffers will be flushed by the final fsync of the devvp in ffs_flushfiles() as intended. (cherry picked from commit 3dc5f8e19d8c975a5e27752d65f9aa91d67c9c9e) --- sys/ufs/ffs/ffs_vfsops.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c index e77d5e336bf1..23d0c9bc60df 100644 --- a/sys/ufs/ffs/ffs_vfsops.c +++ b/sys/ufs/ffs/ffs_vfsops.c @@ -1452,9 +1452,7 @@ ffs_unmount(struct mount *mp, int mntflags) if (susp) vfs_write_resume(mp, VR_START_WRITE); if (ump->um_trim_tq != NULL) { - while (ump->um_trim_inflight != 0) - pause("ufsutr", hz); - taskqueue_drain_all(ump->um_trim_tq); + MPASS(ump->um_trim_inflight == 0); taskqueue_free(ump->um_trim_tq); free (ump->um_trimhash, M_TRIM); } @@ -1564,6 +1562,20 @@ ffs_flushfiles(struct mount *mp, int flags, struct thread *td) if (qerror == 0 && (error = vflush(mp, 0, flags, td)) != 0) return (error); + /* + * If this is a forcible unmount and there were any files that + * were unlinked but still open, then vflush() will have + * truncated and freed those files, which might have started + * some trim work. Wait here for any trims to complete + * and process the blkfrees which follow the trims. + * This may create more dirty devvp buffers and softdep deps. + */ + if (ump->um_trim_tq != NULL) { + while (ump->um_trim_inflight != 0) + pause("ufsutr", hz); + taskqueue_drain_all(ump->um_trim_tq); + } + /* * Flush filesystem metadata. */
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