These ioctls simply freeze and thaw ploop bdev, respectively (i.e. FS mounted over ploop device). They are required by ploop push backup for freezing secondary ploops mounted inside containers. The point is that these mount points are not shown in host's /proc/mounts due to mount namespace, so there's no easy way for push backup process to get the mount point given a device name in order to call FIFREEZE ioctl. (Actually, there's a way - using /proc/PID/mounts and /proc/PID/root where PID is the pid of a container's process, but it's cumbersome).
https://jira.sw.ru/browse/PSBM-49091 Signed-off-by: Vladimir Davydov <[email protected]> Cc: Pavel Borzenkov <[email protected]> --- drivers/block/ploop/dev.c | 28 ++++++++++++++++++++++++++++ include/linux/ploop/ploop_if.h | 6 ++++++ 2 files changed, 34 insertions(+) diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c index e5f010b9aeba..d2b3c9fd9176 100644 --- a/drivers/block/ploop/dev.c +++ b/drivers/block/ploop/dev.c @@ -4815,6 +4815,28 @@ static int ploop_push_backup_stop(struct ploop_device *plo, unsigned long arg) return copy_to_user((void*)arg, &ctl, sizeof(ctl)); } +static int ploop_freeze(struct block_device *bdev) +{ + struct super_block *sb; + + sb = freeze_bdev(bdev); + if (sb && IS_ERR(sb)) + return PTR_ERR(sb); + return 0; +} + +static int ploop_thaw(struct block_device *bdev) +{ + struct super_block *sb; + int err; + + sb = get_active_super(bdev); + err = thaw_bdev(bdev, sb); + if (sb) + deactivate_super(sb); + return err; +} + static int ploop_ioctl(struct block_device *bdev, fmode_t fmode, unsigned int cmd, unsigned long arg) { @@ -4928,6 +4950,12 @@ static int ploop_ioctl(struct block_device *bdev, fmode_t fmode, unsigned int cm case PLOOP_IOC_PUSH_BACKUP_STOP: err = ploop_push_backup_stop(plo, arg); break; + case PLOOP_IOC_FREEZE: + err = ploop_freeze(bdev); + break; + case PLOOP_IOC_THAW: + err = ploop_thaw(bdev); + break; default: err = -EINVAL; } diff --git a/include/linux/ploop/ploop_if.h b/include/linux/ploop/ploop_if.h index a098ca9d0ef0..302ace984a5a 100644 --- a/include/linux/ploop/ploop_if.h +++ b/include/linux/ploop/ploop_if.h @@ -352,6 +352,12 @@ struct ploop_track_extent /* Stop push backup */ #define PLOOP_IOC_PUSH_BACKUP_STOP _IOR(PLOOPCTLTYPE, 31, struct ploop_push_backup_stop_ctl) +/* Freeze FS mounted over ploop */ +#define PLOOP_IOC_FREEZE _IO(PLOOPCTLTYPE, 32) + +/* Unfreeze FS mounted over ploop */ +#define PLOOP_IOC_THAW _IO(PLOOPCTLTYPE, 33) + /* Events exposed via /sys/block/ploopN/pstate/event */ #define PLOOP_EVENT_ABORTED 1 #define PLOOP_EVENT_STOPPED 2 -- 2.1.4 _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
