projects / zfsonlinux.git / blame
| Commit | Line | Data |
|---|---|---|
| 68be554e TL |
1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| 2 | From: Rob Norris <rob.norris@klarasystems.com> | |
| 3 | Date: Tue, 2 Apr 2024 15:14:54 +1100 | |
| 4 | Subject: [PATCH] vdev_disk: don't touch vbio after its handed off to the | |
| 5 | kernel | |
| 6 | ||
| 7 | After IO is unplugged, it may complete immediately and vbio_completion | |
| 8 | be called on interrupt context. That may interrupt or deschedule our | |
| 9 | task. If its the last bio, the vbio will be freed. Then, we get | |
| 10 | rescheduled, and try to write to freed memory through vbio->. | |
| 11 | ||
| 12 | This patch just removes the the cleanup, and the corresponding assert. | |
| 13 | These were leftovers from a previous iteration of vbio_submit() and were | |
| 14 | always "belt and suspenders" ops anyway, never strictly required. | |
| 15 | ||
| 16 | Reported-by: Rich Ercolani <rincebrain@gmail.com> | |
| 17 | Signed-off-by: Rob Norris <rob.norris@klarasystems.com> | |
| 18 | Sponsored-by: Klara, Inc. | |
| 19 | Sponsored-by: Wasabi Technology, Inc. | |
| 20 | (cherry picked from commit 34f662ad22206af6852020fd923ceccd836a855f) | |
| 21 | Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com> | |
| 22 | --- | |
| 23 | module/os/linux/zfs/vdev_disk.c | 11 ++++++----- | |
| 24 | 1 file changed, 6 insertions(+), 5 deletions(-) | |
| 25 | ||
| 26 | diff --git a/module/os/linux/zfs/vdev_disk.c b/module/os/linux/zfs/vdev_disk.c | |
| 27 | index e1c19a085..62c7aa14f 100644 | |
| 28 | --- a/module/os/linux/zfs/vdev_disk.c | |
| 29 | +++ b/module/os/linux/zfs/vdev_disk.c | |
| 30 | @@ -758,8 +758,6 @@ vbio_fill_cb(struct page *page, size_t off, size_t len, void *priv) | |
| 31 | static void | |
| 32 | vbio_submit(vbio_t *vbio, abd_t *abd, uint64_t size) | |
| 33 | { | |
| 34 | - ASSERT(vbio->vbio_bdev); | |
| 35 | - | |
| 36 | /* | |
| 37 | * We plug so we can submit the BIOs as we go and only unplug them when | |
| 38 | * they are fully created and submitted. This is important; if we don't | |
| 39 | @@ -777,12 +775,15 @@ vbio_submit(vbio_t *vbio, abd_t *abd, uint64_t size) | |
| 40 | vbio->vbio_bio->bi_end_io = vbio_completion; | |
| 41 | vbio->vbio_bio->bi_private = vbio; | |
| 42 | ||
| 43 | + /* | |
| 44 | + * Once submitted, vbio_bio now owns vbio (through bi_private) and we | |
| 45 | + * can't touch it again. The bio may complete and vbio_completion() be | |
| 46 | + * called and free the vbio before this task is run again, so we must | |
| 47 | + * consider it invalid from this point. | |
| 48 | + */ | |
| 49 | vdev_submit_bio(vbio->vbio_bio); | |
| 50 | ||
| 51 | blk_finish_plug(&plug); | |
| 52 | - | |
| 53 | - vbio->vbio_bio = NULL; | |
| 54 | - vbio->vbio_bdev = NULL; | |
| 55 | } | |
| 56 | ||
| 57 | /* IO completion callback */ |