| Message ID | b6183586bd5d9dd6f26ff4aaf3bab0a6629c6018.1615479658.git.josef@toxicpanda.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Handle bad dev_root properly with rescue=all | expand |
On 12/3/21 12:23 am, Josef Bacik wrote: > While helping Neal fix his broken file system I added a debug patch to > catch if we were calling btrfs_search_slot with a NULL root, and this > stack trace popped > > we tried to search with a NULL root > CPU: 0 PID: 1760 Comm: mount Not tainted 5.11.0-155.nealbtrfstest.1.fc34.x86_64 #1 > Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/22/2020 > Call Trace: > dump_stack+0x6b/0x83 > btrfs_search_slot.cold+0x11/0x1b > ? btrfs_init_dev_replace+0x36/0x450 > btrfs_init_dev_replace+0x71/0x450 > open_ctree+0x1054/0x1610 > btrfs_mount_root.cold+0x13/0xfa > legacy_get_tree+0x27/0x40 > vfs_get_tree+0x25/0xb0 > vfs_kern_mount.part.0+0x71/0xb0 > btrfs_mount+0x131/0x3d0 > ? legacy_get_tree+0x27/0x40 > ? btrfs_show_options+0x640/0x640 > legacy_get_tree+0x27/0x40 > vfs_get_tree+0x25/0xb0 > path_mount+0x441/0xa80 > __x64_sys_mount+0xf4/0x130 > do_syscall_64+0x33/0x40 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x7f644730352e > > Fix this by not starting the device replace stuff if we do not have a > NULL dev root. > > Reported-by: Neal Gompa <ngompa13@gmail.com> > Signed-off-by: Josef Bacik <josef@toxicpanda.com> > --- > fs/btrfs/dev-replace.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c > index 3a9c1e046ebe..d05f73530af7 100644 > --- a/fs/btrfs/dev-replace.c > +++ b/fs/btrfs/dev-replace.c > @@ -81,6 +81,9 @@ int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) > struct btrfs_dev_replace_item *ptr; > u64 src_devid; > > + if (!dev_root) > + return 0; > + If we have a replace device target. fs_info->dev_replace->is_valid is 0, and btrfs_dev_replace_is_ongoing() is false. And num_device count at various places does not include replace target device. And also this happens only in RO mount. Reviewed-by: Anand Jain <anand.jain@oracle.com> > path = btrfs_alloc_path(); > if (!path) { > ret = -ENOMEM; >
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 3a9c1e046ebe..d05f73530af7 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -81,6 +81,9 @@ int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) struct btrfs_dev_replace_item *ptr; u64 src_devid; + if (!dev_root) + return 0; + path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM;
While helping Neal fix his broken file system I added a debug patch to catch if we were calling btrfs_search_slot with a NULL root, and this stack trace popped we tried to search with a NULL root CPU: 0 PID: 1760 Comm: mount Not tainted 5.11.0-155.nealbtrfstest.1.fc34.x86_64 #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/22/2020 Call Trace: dump_stack+0x6b/0x83 btrfs_search_slot.cold+0x11/0x1b ? btrfs_init_dev_replace+0x36/0x450 btrfs_init_dev_replace+0x71/0x450 open_ctree+0x1054/0x1610 btrfs_mount_root.cold+0x13/0xfa legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x131/0x3d0 ? legacy_get_tree+0x27/0x40 ? btrfs_show_options+0x640/0x640 legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 path_mount+0x441/0xa80 __x64_sys_mount+0xf4/0x130 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f644730352e Fix this by not starting the device replace stuff if we do not have a NULL dev root. Reported-by: Neal Gompa <ngompa13@gmail.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- fs/btrfs/dev-replace.c | 3 +++ 1 file changed, 3 insertions(+)