Make btrfs able to parse vfs_shift_uids and vfs_shift_gids options and
set the appropriate flags into the super_block structure.
vfs_shift_uids and vfs_shift_gids allow mounts that show up in a mount
namespace that supports VFS UID/GID shifts on inodes to perform translation
from in kernel virtual view into on-disk view and vice versa. This
allows user namespaces users to be able to access, read and write inodes
on these mounts.
Signed-off-by: Dongsu Park <dongsu@xxxxxxxxxxxx>
Signed-off-by: Djalal Harouni <tixxdz@xxxxxxxxxx>
---
fs/btrfs/super.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 00b8f37..20e7223 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -304,7 +304,8 @@ enum {
Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
- Opt_nologreplay, Opt_norecovery,
+ Opt_nologreplay, Opt_norecovery, Opt_vfs_shift_uids,
+ Opt_vfs_shift_gids,
#ifdef CONFIG_BTRFS_DEBUG
Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
#endif
@@ -364,6 +365,8 @@ static const match_table_t tokens = {
{Opt_rescan_uuid_tree, "rescan_uuid_tree"},
{Opt_fatal_errors, "fatal_errors=%s"},
{Opt_commit_interval, "commit=%d"},
+ {Opt_vfs_shift_uids, "vfs_shift_uids"},
+ {Opt_vfs_shift_gids, "vfs_shift_gids"},
#ifdef CONFIG_BTRFS_DEBUG
{Opt_fragment_data, "fragment=data"},
{Opt_fragment_metadata, "fragment=metadata"},
@@ -786,6 +789,12 @@ int btrfs_parse_options(struct btrfs_root *root, char *options,
info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
}
break;
+ case Opt_vfs_shift_uids:
+ root->fs_info->sb->s_iflags |= SB_I_VFS_SHIFT_UIDS;
+ break;
+ case Opt_vfs_shift_gids:
+ root->fs_info->sb->s_iflags |= SB_I_VFS_SHIFT_GIDS;
+ break;
#ifdef CONFIG_BTRFS_DEBUG
case Opt_fragment_all:
btrfs_info(root->fs_info, "fragmenting all space");
@@ -1279,6 +1288,10 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
if (btrfs_test_opt(root, FRAGMENT_METADATA))
seq_puts(seq, ",fragment=metadata");
#endif
+ if (root->fs_info->sb->s_iflags & SB_I_VFS_SHIFT_UIDS)
+ seq_puts(seq, ",vfs_shift_uids");
+ if (root->fs_info->sb->s_iflags & SB_I_VFS_SHIFT_GIDS)
+ seq_puts(seq, ",vfs_shift_gids");
seq_printf(seq, ",subvolid=%llu",
BTRFS_I(d_inode(dentry))->root->root_key.objectid);
seq_puts(seq, ",subvol=");
--
2.5.5
--
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