@@ -25,7 +25,8 @@
#include "mount.h"
/**
- * generic_fillattr - Fill in the basic attributes from the inode struct
+ * mapped_generic_fillattr - Fill in the basic attributes from the inode struct on idmapped mounts
+ * @user_ns: the user namespace from which we access this inode
* @inode: Inode to use as the source
* @stat: Where to fill in the attributes
*
@@ -33,14 +34,15 @@
* found on the VFS inode structure. This is the default if no getattr inode
* operation is supplied.
*/
-void generic_fillattr(struct inode *inode, struct kstat *stat)
+void mapped_generic_fillattr(struct user_namespace *mnt_user_ns,
+ struct inode *inode, struct kstat *stat)
{
stat->dev = inode->i_sb->s_dev;
stat->ino = inode->i_ino;
stat->mode = inode->i_mode;
stat->nlink = inode->i_nlink;
- stat->uid = inode->i_uid;
- stat->gid = inode->i_gid;
+ stat->uid = i_uid_into_mnt(mnt_user_ns, inode);
+ stat->gid = i_gid_into_mnt(mnt_user_ns, inode);
stat->rdev = inode->i_rdev;
stat->size = i_size_read(inode);
stat->atime = inode->i_atime;
@@ -49,6 +51,12 @@ void generic_fillattr(struct inode *inode, struct kstat *stat)
stat->blksize = i_blocksize(inode);
stat->blocks = inode->i_blocks;
}
+EXPORT_SYMBOL(mapped_generic_fillattr);
+
+void generic_fillattr(struct inode *inode, struct kstat *stat)
+{
+ mapped_generic_fillattr(&init_user_ns, inode, stat);
+}
EXPORT_SYMBOL(generic_fillattr);
/**
@@ -87,7 +95,7 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
return inode->i_op->getattr(path, stat, request_mask,
query_flags);
- generic_fillattr(inode, stat);
+ mapped_generic_fillattr(mnt_user_ns(path->mnt), inode, stat);
return 0;
}
EXPORT_SYMBOL(vfs_getattr_nosec);
@@ -3162,6 +3162,7 @@ extern int page_symlink(struct inode *inode, const char *symname, int len);
extern const struct inode_operations page_symlink_inode_operations;
extern void kfree_link(void *);
extern void generic_fillattr(struct inode *, struct kstat *);
+extern void mapped_generic_fillattr(struct user_namespace *, struct inode *, struct kstat *);
extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int);
extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
void __inode_add_bytes(struct inode *inode, loff_t bytes);
The generic_fillattr() helper fills in the basic attributes associated with an inode. Add a mapped_generic_fillattr() helper to handle idmapped mounts. If the inode is accessed through an idmapped mount we need to map it according to the mount's user namespace. If the initial user namespace is passed all operations are a nop so non-idmapped mounts will not see a change in behavior and will also not see any performance impact. This also means that the non-idmapped-mount aware generic_fillattr() helper can be implemented on top of the idmapped-mount aware mapped_generic_fillattr() helper. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> --- fs/stat.c | 18 +++++++++++++----- include/linux/fs.h | 1 + 2 files changed, 14 insertions(+), 5 deletions(-)