From 2fc9f6baa24ac230166df41ed636224969523341 Mon Sep 17 00:00:00 2001 From: Eryu Guan Date: Mon, 13 Oct 2014 12:42:12 +0800 Subject: [PATCH] Btrfs: return failure if btrfs_dev_replace_finishing() failed device replace could fail due to another running scrub process or any other errors btrfs_scrub_dev() may hit, but this failure doesn't get returned to userspace. The following steps could reproduce this issue mkfs -t btrfs -f /dev/sdb1 /dev/sdb2 mount /dev/sdb1 /mnt/btrfs while true; do btrfs scrub start -B /mnt/btrfs >/dev/null 2>&1; done & btrfs replace start -Bf /dev/sdb2 /dev/sdb3 /mnt/btrfs # if this replace succeeded, do the following and repeat until # you see this log in dmesg # BTRFS: btrfs_scrub_dev(/dev/sdb2, 2, /dev/sdb3) failed -115 #btrfs replace start -Bf /dev/sdb3 /dev/sdb2 /mnt/btrfs # once you see the error log in dmesg, check return value of # replace echo $? Introduce a new dev replace result BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS to catch -EINPROGRESS explicitly and return other errors directly to userspace. Signed-off-by: Eryu Guan Signed-off-by: Chris Mason --- fs/btrfs/dev-replace.c | 12 +++++++++--- include/uapi/linux/btrfs.h | 1 + 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 6f662b3..971c061 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -422,9 +422,15 @@ int btrfs_dev_replace_start(struct btrfs_root *root, &dev_replace->scrub_progress, 0, 1); ret = btrfs_dev_replace_finishing(root->fs_info, ret); - WARN_ON(ret); + /* don't warn if EINPROGRESS, someone else might be running scrub */ + if (ret == -EINPROGRESS) { + args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; + ret = 0; + } else { + WARN_ON(ret); + } - return 0; + return ret; leave: dev_replace->srcdev = NULL; @@ -542,7 +548,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); - return 0; + return scrub_ret; } printk_in_rcu(KERN_INFO diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index 2f47824..611e1c5 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -157,6 +157,7 @@ struct btrfs_ioctl_dev_replace_status_params { #define BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR 0 #define BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED 1 #define BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED 2 +#define BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS 3 struct btrfs_ioctl_dev_replace_args { __u64 cmd; /* in */ __u64 result; /* out */ -- 2.7.4