| Message ID | 1302082493-14589-1-git-send-email-xin.zhong@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi On 04/06/2011 11:34 AM, Zhong, Xin wrote: > We create two subvolumes (meego_root and meego_home) in > btrfs root directory. And set meego_root as default mount > subvolume. After we remount btrfs, meego_root is mounted > to top directory by default. Then if we create a directory with > the same name as meego_home, we can mount meego_home subvolume > sucessfully (subvol=meego_home). But this is incorrect. What we > do in this mount point will not change anything in meego_home > subvolume. The problem is when default mount subvolume is set to > meego_root, we search meego_home in meego_root. But if we find a > directory with the same name, we will treat it as subvolume. So > the solution is to check if what we find is really a subvolume. I think that this a bug, so a warning should be raised. We had a lot of problem because "btrfsctl -s " did the same thing: if we referred to a directory, they snapshot the directory's subvolume and the user didn't understood what happened. Personally I prefer that in case a wrong option the kernel raises a warning and stops, not that it makes a choice about which default is more reasonable. Reagrds G.Baroncelli > > Signed-off-by: Zhong, Xin <xin.zhong@intel.com> > --- > fs/btrfs/super.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index b85fe78..66a76b7 100644 > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -823,7 +823,9 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags, > error = PTR_ERR(new_root); > goto error_free_subvol_name; > } > - if (!new_root->d_inode) { > + if (!new_root->d_inode || > + /* new_root is a directory, not subvolume */ > + new_root->d_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) { > dput(root); > dput(new_root); > deactivate_locked_super(s); -- 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
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index b85fe78..66a76b7 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -823,7 +823,9 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags, error = PTR_ERR(new_root); goto error_free_subvol_name; } - if (!new_root->d_inode) { + if (!new_root->d_inode || + /* new_root is a directory, not subvolume */ + new_root->d_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) { dput(root); dput(new_root); deactivate_locked_super(s);
We create two subvolumes (meego_root and meego_home) in btrfs root directory. And set meego_root as default mount subvolume. After we remount btrfs, meego_root is mounted to top directory by default. Then if we create a directory with the same name as meego_home, we can mount meego_home subvolume sucessfully (subvol=meego_home). But this is incorrect. What we do in this mount point will not change anything in meego_home subvolume. The problem is when default mount subvolume is set to meego_root, we search meego_home in meego_root. But if we find a directory with the same name, we will treat it as subvolume. So the solution is to check if what we find is really a subvolume. Signed-off-by: Zhong, Xin <xin.zhong@intel.com> --- fs/btrfs/super.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)