From afa7b3484556d3ae610a34582ce5ebd2c3e27bba Mon Sep 17 00:00:00 2001 From: Paul Zuchowski <31706010+PaulZ-98@users.noreply.github.com> Date: Fri, 11 Jun 2021 20:00:33 -0400 Subject: [PATCH] Do not hash unlinked inodes In zfs_znode_alloc we always hash inodes. If the znode is unlinked, we do not need to hash it. This fixes the problem where zfs_suspend_fs is doing zrele (iput) in an async fashion, and zfs_resume_fs unlinked drain processing will try to hash an inode that could still be hashed, resulting in a panic. Reviewed-by: Brian Behlendorf Reviewed-by: Alan Somers Signed-off-by: Paul Zuchowski Closes #9741 Closes #11223 Closes #11648 Closes #12210 --- module/os/linux/zfs/zfs_znode.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/module/os/linux/zfs/zfs_znode.c b/module/os/linux/zfs/zfs_znode.c index 6015aea62d..577927747a 100644 --- a/module/os/linux/zfs/zfs_znode.c +++ b/module/os/linux/zfs/zfs_znode.c @@ -606,17 +606,24 @@ zfs_znode_alloc(zfsvfs_t *zfsvfs, dmu_buf_t *db, int blksz, * number is already hashed for this super block. This can never * happen because the inode numbers map 1:1 with the object numbers. * - * The one exception is rolling back a mounted file system, but in - * this case all the active inode are unhashed during the rollback. + * Exceptions include rolling back a mounted file system, either + * from the zfs rollback or zfs recv command. + * + * Active inodes are unhashed during the rollback, but since zrele + * can happen asynchronously, we can't guarantee they've been + * unhashed. This can cause hash collisions in unlinked drain + * processing so do not hash unlinked znodes. */ - VERIFY3S(insert_inode_locked(ip), ==, 0); + if (links > 0) + VERIFY3S(insert_inode_locked(ip), ==, 0); mutex_enter(&zfsvfs->z_znodes_lock); list_insert_tail(&zfsvfs->z_all_znodes, zp); zfsvfs->z_nr_znodes++; mutex_exit(&zfsvfs->z_znodes_lock); - unlock_new_inode(ip); + if (links > 0) + unlock_new_inode(ip); return (zp); error: