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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/overlayfs.h | |
| parent | 5148626b806a74dd219f2bce5f204abf909f6930 (diff) | |
| download | linux-e487d889b7e3e8ec4091eb83bc4f7e67c7f05e27.tar.bz2 | |
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/overlayfs.h')
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 09779f9111a8..8eefc309aeb6 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -202,7 +202,7 @@ void ovl_drop_write(struct dentry *dentry); struct dentry *ovl_workdir(struct dentry *dentry); const struct cred *ovl_override_creds(struct super_block *sb); struct super_block *ovl_same_sb(struct super_block *sb); -bool ovl_can_decode_fh(struct super_block *sb); +int ovl_can_decode_fh(struct super_block *sb); struct dentry *ovl_indexdir(struct super_block *sb); bool ovl_index_all(struct super_block *sb); bool ovl_verify_lower(struct super_block *sb); @@ -264,6 +264,13 @@ static inline bool ovl_is_impuredir(struct dentry *dentry) return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE); } +static inline unsigned int ovl_xino_bits(struct super_block *sb) +{ + struct ovl_fs *ofs = sb->s_fs_info; + + return ofs->xino_bits; +} + /* namei.c */ int ovl_check_fh_len(struct ovl_fh *fh, int fh_len); |