From 41e1aa2a06f81640c3a3e1a6b12558d95887f662 Mon Sep 17 00:00:00 2001 From: Heitor Alves de Siqueira Date: Fri, 15 Nov 2019 14:56:05 -0300 Subject: [PATCH] Break out of zfs_zget early if unlinked znode If zp->z_unlinked is set, we're working with a znode that has been marked for deletion. If that's the case, we can skip the "goto again" loop and return ENOENT, as the znode should not be discovered. Reviewed-by: Richard Yao Reviewed-by: Matt Ahrens Reviewed-by: Brian Behlendorf Signed-off-by: Heitor Alves de Siqueira Closes #9583 --- module/os/linux/zfs/zfs_znode.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/module/os/linux/zfs/zfs_znode.c b/module/os/linux/zfs/zfs_znode.c index ab24d875ec95..c623d61f7066 100644 --- a/module/os/linux/zfs/zfs_znode.c +++ b/module/os/linux/zfs/zfs_znode.c @@ -1094,6 +1094,9 @@ zfs_zget(zfsvfs_t *zfsvfs, uint64_t obj_num, znode_t **zpp) mutex_enter(&zp->z_lock); ASSERT3U(zp->z_id, ==, obj_num); /* + * If zp->z_unlinked is set, the znode is already marked + * for deletion and should not be discovered. + * * If igrab() returns NULL the VFS has independently * determined the inode should be evicted and has * called iput_final() to start the eviction process. @@ -1107,19 +1110,24 @@ zfs_zget(zfsvfs_t *zfsvfs, uint64_t obj_num, znode_t **zpp) * need to detect the active SA hold thereby informing * the VFS that this inode should not be evicted. */ - if (igrab(ZTOI(zp)) == NULL) { - mutex_exit(&zp->z_lock); - sa_buf_rele(db, NULL); - zfs_znode_hold_exit(zfsvfs, zh); - /* inode might need this to finish evict */ - cond_resched(); - goto again; + if (zp->z_unlinked) { + err = SET_ERROR(ENOENT); + } else if (igrab(ZTOI(zp)) == NULL) { + err = SET_ERROR(EAGAIN); + } else { + *zpp = zp; + err = 0; } - *zpp = zp; - err = 0; + mutex_exit(&zp->z_lock); sa_buf_rele(db, NULL); zfs_znode_hold_exit(zfsvfs, zh); + + if (err == EAGAIN) { + /* inode might need this to finish evict */ + cond_resched(); + goto again; + } return (err); }