From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.fusionio.com ([66.114.96.31]:55334 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756329Ab2FUUGD (ORCPT ); Thu, 21 Jun 2012 16:06:03 -0400 From: Josef Bacik To: , Subject: [PATCH] Btrfs-progs: add btrfs device ready command Date: Thu, 21 Jun 2012 16:10:31 -0400 Message-ID: <1340309431-9972-3-git-send-email-jbacik@fusionio.com> In-Reply-To: <1340309431-9972-1-git-send-email-jbacik@fusionio.com> References: <1340309431-9972-1-git-send-email-jbacik@fusionio.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: This command will be used by things like dracut that wish to know very simply if all of the devices have been added to the kernel cache yet for the device to be fully mounted. This keeps initrd's from constantly having to try to mount the file system until it succeeds every time a device is added to the system. Thanks, Signed-off-by: Josef Bacik --- cmds-device.c | 35 +++++++++++++++++++++++++++++++++++ ioctl.h | 2 ++ 2 files changed, 37 insertions(+), 0 deletions(-) diff --git a/cmds-device.c b/cmds-device.c index db625a6..fccf870 100644 --- a/cmds-device.c +++ b/cmds-device.c @@ -246,11 +246,46 @@ static int cmd_scan_dev(int argc, char **argv) return 0; } +static const char * const cmd_ready_dev_usage[] = { + "btrfs device ready ", + "Check device to see if it has all of it's devices in cache for mounting", + NULL +}; + +static int cmd_ready_dev(int argc, char **argv) +{ + struct btrfs_ioctl_vol_args args; + int fd; + int ret; + + if (check_argc_min(argc, 2)) + usage(cmd_ready_dev_usage); + + fd = open("/dev/btrfs-control", O_RDWR); + if (fd < 0) { + perror("failed to open /dev/btrfs-control"); + return 10; + } + + strncpy(args.name, argv[argc - 1], BTRFS_PATH_NAME_MAX); + ret = ioctl(fd, BTRFS_IOC_DEVICES_READY, &args); + if (ret < 0) { + fprintf(stderr, "ERROR: unable to determine if the device '%s'" + " is ready for mounting - %s\n", argv[argc - 1], + strerror(errno)); + ret = 1; + } + + close(fd); + return ret; +} + const struct cmd_group device_cmd_group = { device_cmd_group_usage, NULL, { { "add", cmd_add_dev, cmd_add_dev_usage, NULL, 0 }, { "delete", cmd_rm_dev, cmd_rm_dev_usage, NULL, 0 }, { "scan", cmd_scan_dev, cmd_scan_dev_usage, NULL, 0 }, + { "ready", cmd_ready_dev, cmd_ready_dev_usage, NULL, 0 }, { 0, 0, 0, 0, 0 } } }; diff --git a/ioctl.h b/ioctl.h index f2e5d8d..e5f8a94 100644 --- a/ioctl.h +++ b/ioctl.h @@ -330,5 +330,7 @@ struct btrfs_ioctl_logical_ino_args { struct btrfs_ioctl_ino_path_args) #define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \ struct btrfs_ioctl_ino_path_args) +#define BTRFS_IOC_DEVICES_READY _IOW(BTRFS_IOCTL_MAGIC, 54, \ + struct btrfs_ioctl_vol_args) #endif -- 1.7.7.6