| Message ID | 20240212165821.1901300-6-aalbersh@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | fs-verity support for XFS | expand |
On Mon, Feb 12, 2024 at 05:58:02PM +0100, Andrey Albershteyn wrote: > +FS_IOC_FSGETXATTR > +----------------- > + > +Since Linux v6.9, FS_XFLAG_VERITY (0x00020000) file attribute is set for verity > +files. The attribute can be observed via lsattr. > + > + [root@vm:~]# lsattr /mnt/test/foo > + --------------------V- /mnt/test/foo > + > +Note that this attribute cannot be set with FS_IOC_FSSETXATTR as enabling verity > +requires input parameters. See FS_IOC_ENABLE_VERITY. The lsattr example is irrelevant and misleading because lsattr uses FS_IOC_GETFLAGS, not FS_IOC_FSGETXATTR. Also, I know that you titled the subsection "FS_IOC_FSGETXATTR", but the text itself should make it super clear that FS_XFLAG_VERITY is only for FS_IOC_FSGETXATTR, not FS_IOC_GETFLAGS. > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h > index 48ad69f7722e..6e63ea832d4f 100644 > --- a/include/uapi/linux/fs.h > +++ b/include/uapi/linux/fs.h > @@ -140,6 +140,7 @@ struct fsxattr { > #define FS_XFLAG_FILESTREAM 0x00004000 /* use filestream allocator */ > #define FS_XFLAG_DAX 0x00008000 /* use DAX for IO */ > #define FS_XFLAG_COWEXTSIZE 0x00010000 /* CoW extent size allocator hint */ > +#define FS_XFLAG_VERITY 0x00020000 /* fs-verity sealed inode */ There's currently nowhere in the documentation or code that uses the phrase "fs-verity sealed inode". It's instead called a verity file, or a file that has fs-verity enabled. We should try to avoid inconsistent terminology. - Eric
On 2024-02-22 20:23:04, Eric Biggers wrote: > On Mon, Feb 12, 2024 at 05:58:02PM +0100, Andrey Albershteyn wrote: > > +FS_IOC_FSGETXATTR > > +----------------- > > + > > +Since Linux v6.9, FS_XFLAG_VERITY (0x00020000) file attribute is set for verity > > +files. The attribute can be observed via lsattr. > > + > > + [root@vm:~]# lsattr /mnt/test/foo > > + --------------------V- /mnt/test/foo > > + > > +Note that this attribute cannot be set with FS_IOC_FSSETXATTR as enabling verity > > +requires input parameters. See FS_IOC_ENABLE_VERITY. > > The lsattr example is irrelevant and misleading because lsattr uses > FS_IOC_GETFLAGS, not FS_IOC_FSGETXATTR. > > Also, I know that you titled the subsection "FS_IOC_FSGETXATTR", but the text > itself should make it super clear that FS_XFLAG_VERITY is only for > FS_IOC_FSGETXATTR, not FS_IOC_GETFLAGS. Sure, I will remove the example. Would something like this be clear enough? FS_IOC_FSGETXATTR ----------------- Since Linux v6.9, FS_XFLAG_VERITY (0x00020000) file attribute is set for verity files. This attribute can be checked with FS_IOC_FSGETXATTR ioctl. Note that this attribute cannot be set with FS_IOC_FSSETXATTR as enabling verity requires input parameters. See FS_IOC_ENABLE_VERITY. > > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h > > index 48ad69f7722e..6e63ea832d4f 100644 > > --- a/include/uapi/linux/fs.h > > +++ b/include/uapi/linux/fs.h > > @@ -140,6 +140,7 @@ struct fsxattr { > > #define FS_XFLAG_FILESTREAM 0x00004000 /* use filestream allocator */ > > #define FS_XFLAG_DAX 0x00008000 /* use DAX for IO */ > > #define FS_XFLAG_COWEXTSIZE 0x00010000 /* CoW extent size allocator hint */ > > +#define FS_XFLAG_VERITY 0x00020000 /* fs-verity sealed inode */ > > There's currently nowhere in the documentation or code that uses the phrase > "fs-verity sealed inode". It's instead called a verity file, or a file that has > fs-verity enabled. We should try to avoid inconsistent terminology. Oops, missed this one. Thanks!
On Fri, Feb 23, 2024 at 01:55:21PM +0100, Andrey Albershteyn wrote: > On 2024-02-22 20:23:04, Eric Biggers wrote: > > On Mon, Feb 12, 2024 at 05:58:02PM +0100, Andrey Albershteyn wrote: > > > +FS_IOC_FSGETXATTR > > > +----------------- > > > + > > > +Since Linux v6.9, FS_XFLAG_VERITY (0x00020000) file attribute is set for verity > > > +files. The attribute can be observed via lsattr. > > > + > > > + [root@vm:~]# lsattr /mnt/test/foo > > > + --------------------V- /mnt/test/foo > > > + > > > +Note that this attribute cannot be set with FS_IOC_FSSETXATTR as enabling verity > > > +requires input parameters. See FS_IOC_ENABLE_VERITY. > > > > The lsattr example is irrelevant and misleading because lsattr uses > > FS_IOC_GETFLAGS, not FS_IOC_FSGETXATTR. > > > > Also, I know that you titled the subsection "FS_IOC_FSGETXATTR", but the text > > itself should make it super clear that FS_XFLAG_VERITY is only for > > FS_IOC_FSGETXATTR, not FS_IOC_GETFLAGS. > > Sure, I will remove the example. Would something like this be clear > enough? > > FS_IOC_FSGETXATTR > ----------------- > > Since Linux v6.9, FS_XFLAG_VERITY (0x00020000) file attribute is set for verity > files. This attribute can be checked with FS_IOC_FSGETXATTR ioctl. Note that > this attribute cannot be set with FS_IOC_FSSETXATTR as enabling verity requires > input parameters. See FS_IOC_ENABLE_VERITY. It's better, but I'd probably put FS_IOC_FSGETXATTR in the first sentence. Like: Since Linux v6.9, the FS_IOC_FSGETXATTR ioctl sets FS_XFLAG_VERITY (0x00020000) in the returned flags when the file has verity enabled. - Eric
diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst index 13e4b18e5dbb..19e59e87999e 100644 --- a/Documentation/filesystems/fsverity.rst +++ b/Documentation/filesystems/fsverity.rst @@ -326,6 +326,18 @@ the file has fs-verity enabled. This can perform better than FS_IOC_GETFLAGS and FS_IOC_MEASURE_VERITY because it doesn't require opening the file, and opening verity files can be expensive. +FS_IOC_FSGETXATTR +----------------- + +Since Linux v6.9, FS_XFLAG_VERITY (0x00020000) file attribute is set for verity +files. The attribute can be observed via lsattr. + + [root@vm:~]# lsattr /mnt/test/foo + --------------------V- /mnt/test/foo + +Note that this attribute cannot be set with FS_IOC_FSSETXATTR as enabling verity +requires input parameters. See FS_IOC_ENABLE_VERITY. + .. _accessing_verity_files: Accessing verity files diff --git a/fs/ioctl.c b/fs/ioctl.c index 76cf22ac97d7..38c00e47c069 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -481,6 +481,8 @@ void fileattr_fill_xflags(struct fileattr *fa, u32 xflags) fa->flags |= FS_DAX_FL; if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT) fa->flags |= FS_PROJINHERIT_FL; + if (fa->fsx_xflags & FS_XFLAG_VERITY) + fa->flags |= FS_VERITY_FL; } EXPORT_SYMBOL(fileattr_fill_xflags); @@ -511,6 +513,8 @@ void fileattr_fill_flags(struct fileattr *fa, u32 flags) fa->fsx_xflags |= FS_XFLAG_DAX; if (fa->flags & FS_PROJINHERIT_FL) fa->fsx_xflags |= FS_XFLAG_PROJINHERIT; + if (fa->flags & FS_VERITY_FL) + fa->fsx_xflags |= FS_XFLAG_VERITY; } EXPORT_SYMBOL(fileattr_fill_flags); @@ -641,6 +645,13 @@ static int fileattr_set_prepare(struct inode *inode, !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) return -EINVAL; + /* + * Verity cannot be set through FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS. + * See FS_IOC_ENABLE_VERITY + */ + if (fa->fsx_xflags & FS_XFLAG_VERITY) + return -EINVAL; + /* Extent size hints of zero turn off the flags. */ if (fa->fsx_extsize == 0) fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT); diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 48ad69f7722e..6e63ea832d4f 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -140,6 +140,7 @@ struct fsxattr { #define FS_XFLAG_FILESTREAM 0x00004000 /* use filestream allocator */ #define FS_XFLAG_DAX 0x00008000 /* use DAX for IO */ #define FS_XFLAG_COWEXTSIZE 0x00010000 /* CoW extent size allocator hint */ +#define FS_XFLAG_VERITY 0x00020000 /* fs-verity sealed inode */ #define FS_XFLAG_HASATTR 0x80000000 /* no DIFLAG for this */ /* the read-only stuff doesn't really belong here, but any other place is
Add extended attribute FS_XFLAG_VERITY for inodes with fs-verity enabled. Signed-off-by: Andrey Albershteyn <aalbersh@redhat.com> --- Documentation/filesystems/fsverity.rst | 12 ++++++++++++ fs/ioctl.c | 11 +++++++++++ include/uapi/linux/fs.h | 1 + 3 files changed, 24 insertions(+)