| Message ID | 20241112202552.3393751-4-viro@zeniv.linux.org.uk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/5] io_statx_prep(): use getname_uflags() | expand |
On Tue, Nov 12, 2024 at 08:25:51PM +0000, Al Viro wrote: > From: Stefan Berger <stefanb@linux.ibm.com> > > Commit 8a924db2d7b5 ("fs: Pass AT_GETATTR_NOSEC flag to getattr interface > function")' introduced the AT_GETATTR_NOSEC flag to ensure that the > call paths only call vfs_getattr_nosec if it is set instead of vfs_getattr. > Now, simplify the getattr interface functions of filesystems where the flag > AT_GETATTR_NOSEC is checked. > > There is only a single caller of inode_operations getattr function and it > is located in fs/stat.c in vfs_getattr_nosec. The caller there is the only > one from which the AT_GETATTR_NOSEC flag is passed from. > > Two filesystems are checking this flag in .getattr and the flag is always > passed to them unconditionally from only vfs_getattr_nosec: > > - ecryptfs: Simplify by always calling vfs_getattr_nosec in > ecryptfs_getattr. From there the flag is passed to no other > function and this function is not called otherwise. > > - overlayfs: Simplify by always calling vfs_getattr_nosec in > ovl_getattr. From there the flag is passed to no other > function and this function is not called otherwise. > > The query_flags in vfs_getattr_nosec will mask-out AT_GETATTR_NOSEC from > any caller using AT_STATX_SYNC_TYPE as mask so that the flag is not > important inside this function. Also, since no filesystem is checking the > flag anymore, remove the flag entirely now, including the BUG_ON check that > never triggered. > > The net change of the changes here combined with the original commit is > that ecryptfs and overlayfs do not call vfs_getattr but only > vfs_getattr_nosec. > > Fixes: 8a924db2d7b5 ("fs: Pass AT_GETATTR_NOSEC flag to getattr interface function") > Reported-by: Al Viro <viro@zeniv.linux.org.uk> > Closes: https://lore.kernel.org/linux-fsdevel/20241101011724.GN1350452@ZenIV/T/#u > Cc: Tyler Hicks <code@tyhicks.com> > Cc: ecryptfs@vger.kernel.org > Cc: Miklos Szeredi <miklos@szeredi.hu> > Cc: Amir Goldstein <amir73il@gmail.com> > Cc: linux-unionfs@vger.kernel.org > Cc: Christian Brauner <brauner@kernel.org> > Cc: linux-fsdevel@vger.kernel.org > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> > --- Reviewed-by: Christian Brauner <brauner@kernel.org>
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 5ed1e4cf6c0b..644e973d5a77 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -1008,14 +1008,6 @@ static int ecryptfs_getattr_link(struct mnt_idmap *idmap, return rc; } -static int ecryptfs_do_getattr(const struct path *path, struct kstat *stat, - u32 request_mask, unsigned int flags) -{ - if (flags & AT_GETATTR_NOSEC) - return vfs_getattr_nosec(path, stat, request_mask, flags); - return vfs_getattr(path, stat, request_mask, flags); -} - static int ecryptfs_getattr(struct mnt_idmap *idmap, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags) @@ -1024,8 +1016,8 @@ static int ecryptfs_getattr(struct mnt_idmap *idmap, struct kstat lower_stat; int rc; - rc = ecryptfs_do_getattr(ecryptfs_dentry_to_lower_path(dentry), - &lower_stat, request_mask, flags); + rc = vfs_getattr_nosec(ecryptfs_dentry_to_lower_path(dentry), + &lower_stat, request_mask, flags); if (!rc) { fsstack_copy_attr_all(d_inode(dentry), ecryptfs_inode_to_lower(d_inode(dentry))); diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 35fd3e3e1778..8b31f44c12cd 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -170,7 +170,7 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, type = ovl_path_real(dentry, &realpath); old_cred = ovl_override_creds(dentry->d_sb); - err = ovl_do_getattr(&realpath, stat, request_mask, flags); + err = vfs_getattr_nosec(&realpath, stat, request_mask, flags); if (err) goto out; @@ -195,8 +195,8 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, (!is_dir ? STATX_NLINK : 0); ovl_path_lower(dentry, &realpath); - err = ovl_do_getattr(&realpath, &lowerstat, lowermask, - flags); + err = vfs_getattr_nosec(&realpath, &lowerstat, lowermask, + flags); if (err) goto out; @@ -248,8 +248,8 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, ovl_path_lowerdata(dentry, &realpath); if (realpath.dentry) { - err = ovl_do_getattr(&realpath, &lowerdatastat, - lowermask, flags); + err = vfs_getattr_nosec(&realpath, &lowerdatastat, + lowermask, flags); if (err) goto out; } else { diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 0bfe35da4b7b..910dbbb2bb7b 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -412,14 +412,6 @@ static inline bool ovl_open_flags_need_copy_up(int flags) return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); } -static inline int ovl_do_getattr(const struct path *path, struct kstat *stat, - u32 request_mask, unsigned int flags) -{ - if (flags & AT_GETATTR_NOSEC) - return vfs_getattr_nosec(path, stat, request_mask, flags); - return vfs_getattr(path, stat, request_mask, flags); -} - /* util.c */ int ovl_get_write_access(struct dentry *dentry); void ovl_put_write_access(struct dentry *dentry); diff --git a/fs/stat.c b/fs/stat.c index 855b995ad09b..011d2160b7af 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -165,7 +165,7 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat, if (inode->i_op->getattr) return inode->i_op->getattr(idmap, path, stat, request_mask, - query_flags | AT_GETATTR_NOSEC); + query_flags); generic_fillattr(idmap, request_mask, inode, stat); return 0; @@ -198,9 +198,6 @@ int vfs_getattr(const struct path *path, struct kstat *stat, { int retval; - if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC)) - return -EPERM; - retval = security_inode_getattr(path); if (retval) return retval; diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index 87e2dec79fea..a40833bf2855 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -154,8 +154,4 @@ usable with open_by_handle_at(2). */ #define AT_HANDLE_MNT_ID_UNIQUE 0x001 /* Return the u64 unique mount ID. */ -#if defined(__KERNEL__) -#define AT_GETATTR_NOSEC 0x80000000 -#endif - #endif /* _UAPI_LINUX_FCNTL_H */