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From: Ilan Schwarts <ilan84@gmail.com>
Date: Mon, 22 Jan 2018 10:07:38 +0200
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Subject: btrfs inode is different across file systems ?
To: linux-btrfs <linux-btrfs@vger.kernel.org>
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Hey,

If I get btrfs inode in this way: btrfs_ino(inode)
implemented at btrfs_inode.h:
static inline u64 btrfs_ino(struct inode *inode)
{
u64 ino = BTRFS_I(inode)->location.objectid;
if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
ino = inode->i_ino;
return ino;
}

Is that inode number is unique between 2 btrfs file systems ?
Lets assume, i have 2 btrfs file systems on my machine, file system A
and file system B, each of these file system has volumes.
is the inode obtained via BTRFS_I(inode)->location.objectid is
guaranteed to be unique across all the btrfs file systems, or just per
the file system this inode is at ?