From: Anand Jain <Anand.Jain@oracle.com>
To: Qu Wenruo <quwenruo@cn.fujitsu.com>, linux-btrfs@vger.kernel.org
Cc: Karel Zak <kzak@redhat.com>
Subject: Re: [PATCH RFC] btrfs: Add ctime/mtime update for btrfs device add/remove.
Date: Fri, 30 May 2014 15:51:31 +0800 [thread overview]
Message-ID: <53883883.8020608@oracle.com> (raw)
In-Reply-To: <1397638952-16691-1-git-send-email-quwenruo@cn.fujitsu.com>
Hi Qu,
In line below...
On 16/04/14 17:02, Qu Wenruo wrote:
> Btrfs will send uevent to udev inform the device change,
> but ctime/mtime for the block device inode is not udpated, which cause
> libblkid used by btrfs-progs unable to detect device change and use old
> cache, causing 'btrfs dev scan; btrfs dev rmove; btrfs dev scan' give an
> error message.
>
> Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
> Cc: Karel Zak <kzak@redhat.com>
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
> fs/btrfs/volumes.c | 26 ++++++++++++++++++++++++--
> 1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 49d7fab..ce232d7 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1452,6 +1452,22 @@ out:
> return ret;
> }
>
> +/*
> + * Function to update ctime/mtime for a given device path.
> + * Mainly used for ctime/mtime based probe like libblkid.
> + */
> +static void update_dev_time(char *path_name)
> +{
> + struct file *filp;
> +
> + filp = filp_open(path_name, O_RDWR, 0);
> + if (!filp)
> + return;
> + file_update_time(filp);
> + filp_close(filp, NULL);
> + return;
> +}
> +
IMO /(I might be wrong) I think its not a good idea to explicitly
achieve this. Since this thread would have already scratched the
device's SB, shouldn't that take care of updating the mtime ?
Thanks, Anand
> static int btrfs_rm_dev_item(struct btrfs_root *root,
> struct btrfs_device *device)
> {
> @@ -1704,10 +1720,14 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
>
> ret = 0;
>
> - /* Notify udev that device has changed */
> - if (bdev)
> + if (bdev) {
> + /* Notify udev that device has changed */
> btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
>
> + /* Update ctime/mtime for device path for libblkid */
> + update_dev_time(device_path);
> + }
> +
> error_brelse:
> brelse(bh);
> if (bdev)
> @@ -2146,6 +2166,8 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
> ret = btrfs_commit_transaction(trans, root);
> }
>
> + /* Update ctime/mtime for libblkid */
> + update_dev_time(device_path);
> return ret;
>
> error_trans:
>
next prev parent reply other threads:[~2014-05-30 7:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-16 9:02 [PATCH RFC] btrfs: Add ctime/mtime update for btrfs device add/remove Qu Wenruo
2014-05-29 12:43 ` David Sterba
2014-05-30 1:27 ` Qu Wenruo
2014-06-04 5:51 ` Qu Wenruo
2014-05-30 7:51 ` Anand Jain [this message]
2014-05-30 7:53 ` Anand Jain
2014-05-30 8:43 ` Qu Wenruo
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