Re: [RFC PATCH v10 07/48] ceph: parse new fscrypt_auth and fscrypt_file fields in inode traces

[Jeff Layton <jlayton@kernel.org>]

On Thu, 2022-02-17 at 16:25 +0800, Xiubo Li wrote:
> On 1/12/22 3:15 AM, Jeff Layton wrote:
> > ...and store them in the ceph_inode_info.
> > 
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > ---
> >   fs/ceph/file.c       |  2 ++
> >   fs/ceph/inode.c      | 18 ++++++++++++++-
> >   fs/ceph/mds_client.c | 55 ++++++++++++++++++++++++++++++++++++++++++++
> >   fs/ceph/mds_client.h |  4 ++++
> >   fs/ceph/super.h      |  6 +++++
> >   5 files changed, 84 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> > index ace72a052254..5937a25ddddd 100644
> > --- a/fs/ceph/file.c
> > +++ b/fs/ceph/file.c
> > @@ -597,6 +597,8 @@ static int ceph_finish_async_create(struct inode *dir, struct inode *inode,
> >   	iinfo.xattr_data = xattr_buf;
> >   	memset(iinfo.xattr_data, 0, iinfo.xattr_len);
> >   
> > +	/* FIXME: set fscrypt_auth and fscrypt_file */
> > +
> >   	in.ino = cpu_to_le64(vino.ino);
> >   	in.snapid = cpu_to_le64(CEPH_NOSNAP);
> >   	in.version = cpu_to_le64(1);	// ???
> > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> > index 649d7a059d7b..d090fe081093 100644
> > --- a/fs/ceph/inode.c
> > +++ b/fs/ceph/inode.c
> > @@ -609,7 +609,10 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
> >   	INIT_WORK(&ci->i_work, ceph_inode_work);
> >   	ci->i_work_mask = 0;
> >   	memset(&ci->i_btime, '\0', sizeof(ci->i_btime));
> > -
> > +#ifdef CONFIG_FS_ENCRYPTION
> > +	ci->fscrypt_auth = NULL;
> > +	ci->fscrypt_auth_len = 0;
> > +#endif
> >   	ceph_fscache_inode_init(ci);
> >   
> >   	return &ci->vfs_inode;
> > @@ -620,6 +623,9 @@ void ceph_free_inode(struct inode *inode)
> >   	struct ceph_inode_info *ci = ceph_inode(inode);
> >   
> >   	kfree(ci->i_symlink);
> > +#ifdef CONFIG_FS_ENCRYPTION
> > +	kfree(ci->fscrypt_auth);
> > +#endif
> >   	kmem_cache_free(ceph_inode_cachep, ci);
> >   }
> >   
> > @@ -1020,6 +1026,16 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
> >   		xattr_blob = NULL;
> >   	}
> >   
> > +#ifdef CONFIG_FS_ENCRYPTION
> > +	if (iinfo->fscrypt_auth_len && !ci->fscrypt_auth) {
> > +		ci->fscrypt_auth_len = iinfo->fscrypt_auth_len;
> > +		ci->fscrypt_auth = iinfo->fscrypt_auth;
> > +		iinfo->fscrypt_auth = NULL;
> > +		iinfo->fscrypt_auth_len = 0;
> > +		inode_set_flags(inode, S_ENCRYPTED, S_ENCRYPTED);
> > +	}
> > +#endif
> > +
> >   	/* finally update i_version */
> >   	if (le64_to_cpu(info->version) > ci->i_version)
> >   		ci->i_version = le64_to_cpu(info->version);
> > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> > index 57cf21c9199f..bd824e989449 100644
> > --- a/fs/ceph/mds_client.c
> > +++ b/fs/ceph/mds_client.c
> > @@ -184,8 +184,50 @@ static int parse_reply_info_in(void **p, void *end,
> >   			info->rsnaps = 0;
> >   		}
> >   
> > +		if (struct_v >= 5) {
> > +			u32 alen;
> > +
> > +			ceph_decode_32_safe(p, end, alen, bad);
> > +
> > +			while (alen--) {
> > +				u32 len;
> > +
> > +				/* key */
> > +				ceph_decode_32_safe(p, end, len, bad);
> > +				ceph_decode_skip_n(p, end, len, bad);
> > +				/* value */
> > +				ceph_decode_32_safe(p, end, len, bad);
> > +				ceph_decode_skip_n(p, end, len, bad);
> > +			}
> > +		}
> > +
> > +		/* fscrypt flag -- ignore */
> > +		if (struct_v >= 6)
> > +			ceph_decode_skip_8(p, end, bad);
> > +
> > +		info->fscrypt_auth = NULL;
> > +		info->fscrypt_file = NULL;
> 
> The 'fscrypt_auth_len' and 'fscrypt_file_len' should also be reset here. 
> Or we will hit the issue I mentioned as bellow:
> 
> 
> cp: cannot access './dir___683': No buffer space available
> cp: cannot access './dir___686': No buffer space available
> 
> The dmesg logs:
> 
> <7>[ 1256.918250] ceph:  readdir 0000000089964a71 file 00000000065cb689
> pos 0
> <7>[ 1256.918254] ceph:  readdir off 0 -> '.'
> <7>[ 1256.918258] ceph:  readdir off 1 -> '..'
> <4>[ 1256.918262] fscrypt (ceph, inode 1099511630270): Error -105
> getting encryption context
> <7>[ 1256.918269] ceph:  readdir 0000000089964a71 file 00000000065cb689
> pos 2
> <4>[ 1256.918273] fscrypt (ceph, inode 1099511630270): Error -105
> getting encryption context
> 
> 
> This can be reproduced when using an old ceph cluster without fscrypt 
> support.
> 
> And also I have sent out one fix to zero the memory when allocating it 
> in ceph_readdir() to fix the potential bug like this.
> 
> Thanks
> 
> BRs
> 
> -- Xiubo
> 
> 

Good catch, Xiubo.

I merged your patch into the testing branch, and fixed this patch to
also zero out the fscrypt_auth_len and fscrypt_file_len. I've also
rebased the wip-fscrypt branch onto the current testing branch.

> > +		if (struct_v >= 7) {
> > +			ceph_decode_32_safe(p, end, info->fscrypt_auth_len, bad);
> > +			if (info->fscrypt_auth_len) {
> > +				info->fscrypt_auth = kmalloc(info->fscrypt_auth_len, GFP_KERNEL);
> > +				if (!info->fscrypt_auth)
> > +					return -ENOMEM;
> > +				ceph_decode_copy_safe(p, end, info->fscrypt_auth,
> > +						      info->fscrypt_auth_len, bad);
> > +			}
> > +			ceph_decode_32_safe(p, end, info->fscrypt_file_len, bad);
> > +			if (info->fscrypt_file_len) {
> > +				info->fscrypt_file = kmalloc(info->fscrypt_file_len, GFP_KERNEL);
> > +				if (!info->fscrypt_file)
> > +					return -ENOMEM;
> > +				ceph_decode_copy_safe(p, end, info->fscrypt_file,
> > +						      info->fscrypt_file_len, bad);
> > +			}
> > +		}
> >   		*p = end;
> >   	} else {
> > +		/* legacy (unversioned) struct */
> >   		if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
> >   			ceph_decode_64_safe(p, end, info->inline_version, bad);
> >   			ceph_decode_32_safe(p, end, info->inline_len, bad);
> > @@ -626,8 +668,21 @@ static int parse_reply_info(struct ceph_mds_session *s, struct ceph_msg *msg,
> >   
> >   static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
> >   {
> > +	int i;
> > +
> > +	kfree(info->diri.fscrypt_auth);
> > +	kfree(info->diri.fscrypt_file);
> > +	kfree(info->targeti.fscrypt_auth);
> > +	kfree(info->targeti.fscrypt_file);
> >   	if (!info->dir_entries)
> >   		return;
> > +
> > +	for (i = 0; i < info->dir_nr; i++) {
> > +		struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
> > +
> > +		kfree(rde->inode.fscrypt_auth);
> > +		kfree(rde->inode.fscrypt_file);
> > +	}
> >   	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
> >   }
> >   
> > diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
> > index c3986a412fb5..98a8710807d1 100644
> > --- a/fs/ceph/mds_client.h
> > +++ b/fs/ceph/mds_client.h
> > @@ -88,6 +88,10 @@ struct ceph_mds_reply_info_in {
> >   	s32 dir_pin;
> >   	struct ceph_timespec btime;
> >   	struct ceph_timespec snap_btime;
> > +	u8 *fscrypt_auth;
> > +	u8 *fscrypt_file;
> > +	u32 fscrypt_auth_len;
> > +	u32 fscrypt_file_len;
> >   	u64 rsnaps;
> >   	u64 change_attr;
> >   };
> > diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> > index 532ee9fca878..5b4092e5f291 100644
> > --- a/fs/ceph/super.h
> > +++ b/fs/ceph/super.h
> > @@ -433,6 +433,12 @@ struct ceph_inode_info {
> >   	struct work_struct i_work;
> >   	unsigned long  i_work_mask;
> >   
> > +#ifdef CONFIG_FS_ENCRYPTION
> > +	u32 fscrypt_auth_len;
> > +	u32 fscrypt_file_len;
> > +	u8 *fscrypt_auth;
> > +	u8 *fscrypt_file;
> > +#endif
> >   #ifdef CONFIG_CEPH_FSCACHE
> >   	struct fscache_cookie *fscache;
> >   #endif
> 

-- 
Jeff Layton <jlayton@kernel.org>