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| author |   Amir Goldstein <amir73il@gmail.com> | 2017-11-07 13:55:04 +0200 |
|---|---|---|
| committer |   Miklos Szeredi <mszeredi@redhat.com> | 2018-04-12 12:04:50 +0200 |
| commit | e487d889b7e3e8ec4091eb83bc4f7e67c7f05e27 (patch) | |
| tree | bab0024b22cbfacdacc7892cdad93129101fe8bc /fs/overlayfs/ovl_entry.h | |
| parent | ovl: allocate anon bdev per unique lower fs (diff) | |
| download | linux-dev-e487d889b7e3e8ec4091eb83bc4f7e67c7f05e27.tar.xz linux-dev-e487d889b7e3e8ec4091eb83bc4f7e67c7f05e27.zip | |
ovl: constant st_ino for non-samefs with xino
On 64bit systems, when overlay layers are not all on the same fs, but
all inode numbers of underlying fs are not using the high bits, use the
high bits to partition the overlay st_ino address space. The high bits
hold the fsid (upper fsid is 0). This way overlay inode numbers are unique
and all inodes use overlay st_dev. Inode numbers are also persistent
for a given layer configuration.
Currently, our only indication for available high ino bits is from a
filesystem that supports file handles and uses the default encode_fh()
operation, which encodes a 32bit inode number.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/ovl_entry.h')
| -rw-r--r-- | fs/overlayfs/ovl_entry.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index e1c838c27a74..620bd20f9a22 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -63,6 +63,8 @@ struct ovl_fs { /* Did we take the inuse lock? */ bool upperdir_locked; bool workdir_locked; + /* Inode numbers in all layers do not use the high xino_bits */ + unsigned int xino_bits; }; /* private information held for every overlayfs dentry */ |