From 668e48af7a94985be7cf3b97a860d9819271d8bf Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Mon, 6 Jan 2020 19:38:31 +0800 Subject: btrfs: sysfs, add devid/dev_state kobject and device attributes New sysfs attributes that track the filesystem status of devices, stored in the per-filesystem directory in /sys/fs/btrfs/FSID/devinfo . There's a directory for each device, with name corresponding to the numerical device id. in_fs_metadata - device is in the list of fs metadata missing - device is missing (no device node or block device) replace_target - device is target of replace writeable - writes from fs are allowed These attributes reflect the state of the device::dev_state and created at mount time. Sample output: $ pwd /sys/fs/btrfs/6e1961f1-5918-4ecc-a22f-948897b409f7/devinfo/1/ $ ls in_fs_metadata missing replace_target writeable $ cat missing 0 The output from these attributes are 0 or 1. 0 indicates unset and 1 indicates set. These attributes are readonly. It is observed that the device delete thread and sysfs read thread will not race because the delete thread calls sysfs kobject_put() which in turn waits for existing sysfs read to complete. Note for device replace devid swap: During the replace the target device temporarily assumes devid 0 before assigning the devid of the soruce device. In btrfs_dev_replace_finishing() we remove source sysfs devid using the function btrfs_sysfs_remove_devices_attr(), so after that call kobject_rename() to update the devid in the sysfs. This adds and calls btrfs_sysfs_update_devid() helper function to update the device id. Signed-off-by: Anand Jain Reviewed-by: David Sterba [ update changelog ] Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index f639dde2a679..8600beb9c086 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -707,6 +707,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, /* replace the sysfs entry */ btrfs_sysfs_rm_device_link(fs_info->fs_devices, src_device); + btrfs_sysfs_update_devid(tgt_device); btrfs_rm_dev_replace_free_srcdev(src_device); /* write back the superblocks */ -- cgit v1.2.3-59-g8ed1b From 4cea9037f82a6deed0f2f61e4054b7ae2519ef87 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Sat, 25 Jan 2020 12:35:38 +0100 Subject: btrfs: dev-replace: remove warning for unknown return codes when finished The fstests btrfs/011 triggered a warning at the end of device replace, [ 1891.998975] BTRFS warning (device vdd): failed setting block group ro: -28 [ 1892.038338] BTRFS error (device vdd): btrfs_scrub_dev(/dev/vdd, 1, /dev/vdb) failed -28 [ 1892.059993] ------------[ cut here ]------------ [ 1892.063032] WARNING: CPU: 2 PID: 2244 at fs/btrfs/dev-replace.c:506 btrfs_dev_replace_start.cold+0xf9/0x140 [btrfs] [ 1892.074346] CPU: 2 PID: 2244 Comm: btrfs Not tainted 5.5.0-rc7-default+ #942 [ 1892.079956] RIP: 0010:btrfs_dev_replace_start.cold+0xf9/0x140 [btrfs] [ 1892.096576] RSP: 0018:ffffbb58c7b3fd10 EFLAGS: 00010286 [ 1892.098311] RAX: 00000000ffffffe4 RBX: 0000000000000001 RCX: 8888888888888889 [ 1892.100342] RDX: 0000000000000001 RSI: ffff9e889645f5d8 RDI: ffffffff92821080 [ 1892.102291] RBP: ffff9e889645c000 R08: 000001b8878fe1f6 R09: 0000000000000000 [ 1892.104239] R10: ffffbb58c7b3fd08 R11: 0000000000000000 R12: ffff9e88a0017000 [ 1892.106434] R13: ffff9e889645f608 R14: ffff9e88794e1000 R15: ffff9e88a07b5200 [ 1892.108642] FS: 00007fcaed3f18c0(0000) GS:ffff9e88bda00000(0000) knlGS:0000000000000000 [ 1892.111558] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1892.113492] CR2: 00007f52509ff420 CR3: 00000000603dd002 CR4: 0000000000160ee0 [ 1892.115814] Call Trace: [ 1892.116896] btrfs_dev_replace_by_ioctl+0x35/0x60 [btrfs] [ 1892.118962] btrfs_ioctl+0x1d62/0x2550 [btrfs] caused by the previous patch ("btrfs: scrub: Require mandatory block group RO for dev-replace"). Hitting ENOSPC is possible and could happen when the block group is set read-only, preventing NOCOW writes to the area that's being accessed by dev-replace. This has happend with scratch devices of size 12G but not with 5G and 20G, so this is depends on timing and other activity on the filesystem. The whole replace operation is restartable, the space state should be examined by the user in any case. The error code is propagated back to the ioctl caller so the kernel warning is causing false alerts. Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index f639dde2a679..ba4d8f375b3c 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -500,11 +500,8 @@ static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, &dev_replace->scrub_progress, 0, 1); ret = btrfs_dev_replace_finishing(fs_info, ret); - if (ret == -EINPROGRESS) { + if (ret == -EINPROGRESS) ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; - } else if (ret != -ECANCELED) { - WARN_ON(ret); - } return ret; -- cgit v1.2.3-59-g8ed1b