From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sage Weil Subject: Re: [PATCH 1/5] btrfs: Make async snapshot ioctl more generic Date: Mon, 29 Nov 2010 11:28:41 -0800 (PST) Message-ID: References: <4CF35E17.6050705@cn.fujitsu.com> <4CF35E28.4070206@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: linux-btrfs@vger.kernel.org To: Li Zefan Return-path: In-Reply-To: <4CF35E28.4070206@cn.fujitsu.com> List-ID: Hi Li, On Mon, 29 Nov 2010, Li Zefan wrote: > So we don't have to add new structures as we create more ioctls > for snapshots. > > Now to create async snapshot, set BTRFS_SNAPSHOT_CREATE_ASYNC bit of > vol_arg_v2->flags, and then call ioctl(BTRFS_IOCT_SNAP_CREATE_V2). > > Note: this changes the async snapshot ioctl ABI, which was merged > in .37 merge window, so we have to make this change into .37. These changes all look good to me. Thanks! sage > > Signed-off-by: Li Zefan > --- > fs/btrfs/ioctl.c | 34 +++++++++++++++++++++------------- > fs/btrfs/ioctl.h | 12 ++++++++---- > 2 files changed, 29 insertions(+), 17 deletions(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 463d91b..d3f1a60 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -935,23 +935,31 @@ out: > > static noinline int btrfs_ioctl_snap_create(struct file *file, > void __user *arg, int subvol, > - int async) > + bool v2) > { > struct btrfs_ioctl_vol_args *vol_args = NULL; > - struct btrfs_ioctl_async_vol_args *async_vol_args = NULL; > + struct btrfs_ioctl_vol_args_v2 *vol_args_v2 = NULL; > char *name; > u64 fd; > u64 transid = 0; > + bool async = false; > int ret; > > - if (async) { > - async_vol_args = memdup_user(arg, sizeof(*async_vol_args)); > - if (IS_ERR(async_vol_args)) > - return PTR_ERR(async_vol_args); > + if (v2) { > + vol_args_v2 = memdup_user(arg, sizeof(*vol_args_v2)); > + if (IS_ERR(vol_args_v2)) > + return PTR_ERR(vol_args_v2); > > - name = async_vol_args->name; > - fd = async_vol_args->fd; > - async_vol_args->name[BTRFS_SNAPSHOT_NAME_MAX] = '\0'; > + if (vol_args_v2->flags & ~BTRFS_SNAPSHOT_CREATE_ASYNC) { > + ret = -EINVAL; > + goto out; > + } > + > + name = vol_args_v2->name; > + fd = vol_args_v2->fd; > + vol_args_v2->name[BTRFS_SNAPSHOT_NAME_MAX] = '\0'; > + if (vol_args_v2->flags & BTRFS_SNAPSHOT_CREATE_ASYNC) > + async = true; > } else { > vol_args = memdup_user(arg, sizeof(*vol_args)); > if (IS_ERR(vol_args)) > @@ -966,13 +974,13 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, > > if (!ret && async) { > if (copy_to_user(arg + > - offsetof(struct btrfs_ioctl_async_vol_args, > + offsetof(struct btrfs_ioctl_vol_args_v2, > transid), &transid, sizeof(transid))) > return -EFAULT; > } > - > +out: > kfree(vol_args); > - kfree(async_vol_args); > + kfree(vol_args_v2); > > return ret; > } > @@ -2235,7 +2243,7 @@ long btrfs_ioctl(struct file *file, unsigned int > return btrfs_ioctl_getversion(file, argp); > case BTRFS_IOC_SNAP_CREATE: > return btrfs_ioctl_snap_create(file, argp, 0, 0); > - case BTRFS_IOC_SNAP_CREATE_ASYNC: > + case BTRFS_IOC_SNAP_CREATE_V2: > return btrfs_ioctl_snap_create(file, argp, 0, 1); > case BTRFS_IOC_SUBVOL_CREATE: > return btrfs_ioctl_snap_create(file, argp, 1, 0); > diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h > index 17c99eb..bc70584 100644 > --- a/fs/btrfs/ioctl.h > +++ b/fs/btrfs/ioctl.h > @@ -30,10 +30,14 @@ struct btrfs_ioctl_vol_args { > char name[BTRFS_PATH_NAME_MAX + 1]; > }; > > -#define BTRFS_SNAPSHOT_NAME_MAX 4079 > -struct btrfs_ioctl_async_vol_args { > +#define BTRFS_SNAPSHOT_CREATE_ASYNC (1ULL << 0) > + > +#define BTRFS_SNAPSHOT_NAME_MAX 4039 > +struct btrfs_ioctl_vol_args_v2 { > __s64 fd; > __u64 transid; > + __u64 flags; > + __u64 unused[4]; > char name[BTRFS_SNAPSHOT_NAME_MAX + 1]; > }; > > @@ -187,6 +191,6 @@ struct btrfs_ioctl_space_args { > struct btrfs_ioctl_space_args) > #define BTRFS_IOC_START_SYNC _IOR(BTRFS_IOCTL_MAGIC, 24, __u64) > #define BTRFS_IOC_WAIT_SYNC _IOW(BTRFS_IOCTL_MAGIC, 22, __u64) > -#define BTRFS_IOC_SNAP_CREATE_ASYNC _IOW(BTRFS_IOCTL_MAGIC, 23, \ > - struct btrfs_ioctl_async_vol_args) > +#define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \ > + struct btrfs_ioctl_vol_args_v2) > #endif > -- > 1.6.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >