linux-kernel - Re: [PATCH] f2fs-tools: fix do_set

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Message-ID: <CAOsHCa0bUg3Kam_4G=aiWzQpisn7rAS3nQWMQEPWB04==Sftbw@mail.gmail.com>
Date: Tue, 18 Jun 2024 13:35:31 +0800
From: Xiuhong Wang <xiuhong.wang.cn@...il.com>
To: Chao Yu <chao@...nel.org>
Cc: Xiuhong Wang <xiuhong.wang@...soc.com>, jaegeuk@...nel.org, 
	linux-f2fs-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org, 
	niuzhiguo84@...il.com, ke.wang@...soc.com, hao_hao.wang@...soc.com
Subject: Re: [PATCH] f2fs-tools: fix do_set_verity ioctl fail issue

Chao Yu <chao@...nel.org> 于2024年6月18日周二 11:04写道：

>
> On 2024/6/17 15:11, Xiuhong Wang wrote:
> > When using the f2fs_io tool to set_verity, it will fail as follows:
> > unisc:/data # ./f2fs_io set_verity file
> > FS_IOC_ENABLE_VERITY: Inappropriate ioctl for device
> > this is because commit: 95ae251fe828 ("f2fs: add fs-verity support"),
> > the passed parameters do not match the latest kernel version.
> >
> > After patch:
> > unisoc:/data # ./f2fs_io set_verity file
> > Set fsverity bit to file
> > unisoc:/data # ./f2fs_io getflags file
> > get a flag on file ret=0, flags=verity
> >
> > Fixes: 95ae251fe828 ("f2fs: add fs-verity support")
> > Signed-off-by: Xiuhong Wang <xiuhong.wang@...soc.com>
> > Signed-off-by: Zhiguo Niu <zhiguo.niu@...soc.com>
> > ---
> >   include/android_config.h |  1 +
> >   tools/f2fs_io/f2fs_io.c  |  9 ++++++---
> >   tools/f2fs_io/f2fs_io.h  | 20 ++++++++++++++++++--
> >   3 files changed, 25 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/android_config.h b/include/android_config.h
> > index 05b686e..9c8b163 100644
> > --- a/include/android_config.h
> > +++ b/include/android_config.h
> > @@ -13,6 +13,7 @@
> >   #define HAVE_LINUX_XATTR_H 1
> >   #define HAVE_LINUX_FS_H 1
> >   #define HAVE_LINUX_FIEMAP_H 1
> > +#define HAVE_LINUX_VERITY_H 1
> >   #define HAVE_MNTENT_H 1
> >   #define HAVE_STDLIB_H 1
> >   #define HAVE_STRING_H 1
> > diff --git a/tools/f2fs_io/f2fs_io.c b/tools/f2fs_io/f2fs_io.c
> > index a7b593a..2447490 100644
> > --- a/tools/f2fs_io/f2fs_io.c
> > +++ b/tools/f2fs_io/f2fs_io.c
> > @@ -182,16 +182,19 @@ static void do_fsync(int argc, char **argv, const struct cmd_desc *cmd)
> >   static void do_set_verity(int argc, char **argv, const struct cmd_desc *cmd)
> >   {
> >       int ret, fd;
> > +     struct fsverity_enable_arg args = {.version = 1};
> > +
> > +     args.hash_algorithm = FS_VERITY_HASH_ALG_SHA256;
> > +     args.block_size = 4096;
> >
> >       if (argc != 2) {
> >               fputs("Excess arguments\n\n", stderr);
> >               fputs(cmd->cmd_help, stderr);
> >               exit(1);
> >       }
> > +     fd = open(argv[1], O_RDONLY);
> >
> > -     fd = open(argv[1], O_RDWR);
>
> It needs write permission?
>
> Thanks,
>
If you open the file with O_RDWR, the following error will be returned:
unisoc:/data # ./f2fs_io set_verity file
FS_IOC_ENABLE_VERITY: Text file busy

/Documentation/filesystems/fsverity.rst has the following description:
FS_IOC_ENABLE_VERITY checks for write access to the inode. However, it
must be executed on an O_RDONLY file descriptor and no processes can
have the file open for writing. Attempts to open the file for writing
while this ioctl is executing will fail with ETXTBSY. (This is
necessary to guarantee that no writable file descriptors will exist
after verity is enabled, and to guarantee that the file's contents are
stable while the Merkle tree is being built over it.)

> > -
> > -     ret = ioctl(fd, FS_IOC_ENABLE_VERITY);
> > +     ret = ioctl(fd, FS_IOC_ENABLE_VERITY, &args);
> >       if (ret < 0) {
> >               perror("FS_IOC_ENABLE_VERITY");
> >               exit(1);
> > diff --git a/tools/f2fs_io/f2fs_io.h b/tools/f2fs_io/f2fs_io.h
> > index b5c82f5..e55db5f 100644
> > --- a/tools/f2fs_io/f2fs_io.h
> > +++ b/tools/f2fs_io/f2fs_io.h
> > @@ -16,6 +16,9 @@
> >   #ifdef HAVE_LINUX_FS_H
> >   #include <linux/fs.h>
> >   #endif
> > +#ifdef HAVE_LINUX_VERITY_H
> > +#include <linux/fsverity.h>
> > +#endif
> >
> >   #include <sys/types.h>
> >
> > @@ -136,8 +139,21 @@ struct fscrypt_get_policy_ex_arg {
> >   #define F2FS_IOC_GET_ENCRYPTION_POLICY      FS_IOC_GET_ENCRYPTION_POLICY
> >   #define F2FS_IOC_GET_ENCRYPTION_PWSALT      FS_IOC_GET_ENCRYPTION_PWSALT
> >
> > -#define FS_IOC_ENABLE_VERITY         _IO('f', 133)
> > -
> > +#ifndef FS_IOC_ENABLE_VERITY
> > +#define FS_IOC_ENABLE_VERITY    _IOW('f', 133, struct fsverity_enable_arg)
> > +#define FS_VERITY_HASH_ALG_SHA256       1
> > +struct fsverity_enable_arg {
> > +     __u32 version;
> > +     __u32 hash_algorithm;
> > +     __u32 block_size;
> > +     __u32 salt_size;
> > +     __u64 salt_ptr;
> > +     __u32 sig_size;
> > +     __u32 __reserved1;
> > +     __u64 sig_ptr;
> > +     __u64 __reserved2[11];
> > +};
> > +#endif
> >   /*
> >    * Inode flags
> >    */