diff options
| author | Brian Behlendorf <[email protected]> | 2020-02-28 08:58:39 -0800 |
|---|---|---|
| committer | GitHub <[email protected]> | 2020-02-28 08:58:39 -0800 |
| commit | bd0d24e09b089af589ebaecd9e85d9fd4ac31deb (patch) | |
| tree | 929a38a76c16333e79d637954e72ee3486264b89 /module | |
| parent | 2ce90dca91a991592da48c52332326ae4bb25b69 (diff) | |
Linux 5.5 compat: blkg_tryget()
Commit https://github.com/torvalds/linux/commit/9e8d42a0f accidentally
converted the static inline function blkg_tryget() to GPL-only for
kernels built with CONFIG_PREEMPT_RCU=y and CONFIG_BLK_CGROUP=y.
Resolve the build issue by providing our own equivalent functionality
when needed which uses rcu_read_lock_sched() internally as before.
Reviewed-by: Tony Hutter <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #9745
Closes #10072
Diffstat (limited to 'module')
| -rw-r--r-- | module/os/linux/zfs/vdev_disk.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/module/os/linux/zfs/vdev_disk.c b/module/os/linux/zfs/vdev_disk.c index cbe9e1831..66e408c6c 100644 --- a/module/os/linux/zfs/vdev_disk.c +++ b/module/os/linux/zfs/vdev_disk.c @@ -457,6 +457,36 @@ vdev_submit_bio_impl(struct bio *bio) #ifdef HAVE_BIO_SET_DEV #if defined(CONFIG_BLK_CGROUP) && defined(HAVE_BIO_SET_DEV_GPL_ONLY) /* + * The Linux 5.5 kernel updated percpu_ref_tryget() which is inlined by + * blkg_tryget() to use rcu_read_lock() instead of rcu_read_lock_sched(). + * As a side effect the function was converted to GPL-only. Define our + * own version when needed which uses rcu_read_lock_sched(). + */ +#if defined(HAVE_BLKG_TRYGET_GPL_ONLY) +static inline bool +vdev_blkg_tryget(struct blkcg_gq *blkg) +{ + struct percpu_ref *ref = &blkg->refcnt; + unsigned long __percpu *count; + bool rc; + + rcu_read_lock_sched(); + + if (__ref_is_percpu(ref, &count)) { + this_cpu_inc(*count); + rc = true; + } else { + rc = atomic_long_inc_not_zero(&ref->count); + } + + rcu_read_unlock_sched(); + + return (rc); +} +#elif defined(HAVE_BLKG_TRYGET) +#define vdev_blkg_tryget(bg) blkg_tryget(bg) +#endif +/* * The Linux 5.0 kernel updated the bio_set_dev() macro so it calls the * GPL-only bio_associate_blkg() symbol thus inadvertently converting * the entire macro. Provide a minimal version which always assigns the @@ -470,7 +500,7 @@ vdev_bio_associate_blkg(struct bio *bio) ASSERT3P(q, !=, NULL); ASSERT3P(bio->bi_blkg, ==, NULL); - if (q->root_blkg && blkg_tryget(q->root_blkg)) + if (q->root_blkg && vdev_blkg_tryget(q->root_blkg)) bio->bi_blkg = q->root_blkg; } #define bio_associate_blkg vdev_bio_associate_blkg |