On 05/02/2021 19:04, Bob Peterson wrote:
Hi,Comments below. ----- Original Message -----From: Andreas Gruenbacher <agrue...@redhat.com> Add support for an additional filesystem version (sb_fs_format = 1802). When a filesystem with the new version is mounted, the filesystem supports "trusted.*" xattrs. In addition, version 1802 filesystems implement a form of forward compatibility for xattrs: when xattrs with an unknown prefix (ea_type) are found on a version 1802 filesystem, those attributes are not shown by listxattr, and they are not accessible by getxattr, setxattr, or removexattr. This mechanism might turn out to be what we need in the future, but if not, we can always bump the filesystem version and break compatibility instead. Signed-off-by: Andrew Price <anpr...@redhat.com>If this is from Andreas, it should have his Signed-off-by:
Yes, it wasn't in the original patch (posted on bugzilla). With Andreas' permission I'll add it to the next version.
--- fs/gfs2/ops_fstype.c | 14 +++++++++- fs/gfs2/super.h | 4 ++- fs/gfs2/xattr.c | 48 +++++++++++++++++++++++++++++--- include/uapi/linux/gfs2_ondisk.h | 5 ++-- 4 files changed, 63 insertions(+), 8 deletions(-) diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index 52fe78378faa..64ad19bb978c 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -489,6 +489,19 @@ static int init_sb(struct gfs2_sbd *sdp, int silent) goto out; }+ switch(sdp->sd_sb.sb_fs_format) {+ case GFS2_FS_FORMAT_MAX: + sb->s_xattr = gfs2_xattr_handlers_max; + break; + + case GFS2_FS_FORMAT_MIN: + sb->s_xattr = gfs2_xattr_handlers_min; + break; + + default: + BUG(); + } + /* Set up the buffer cache and SB for real */ if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) { ret = -EINVAL; @@ -1109,7 +1122,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_op = &gfs2_super_ops; sb->s_d_op = &gfs2_dops; sb->s_export_op = &gfs2_export_ops; - sb->s_xattr = gfs2_xattr_handlers; sb->s_qcop = &gfs2_quotactl_ops; sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP; sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE; diff --git a/fs/gfs2/super.h b/fs/gfs2/super.h index 977079693bdc..08e502dec7ec 100644 --- a/fs/gfs2/super.h +++ b/fs/gfs2/super.h @@ -58,7 +58,9 @@ extern struct file_system_type gfs2meta_fs_type; extern const struct export_operations gfs2_export_ops; extern const struct super_operations gfs2_super_ops; extern const struct dentry_operations gfs2_dops; -extern const struct xattr_handler *gfs2_xattr_handlers[]; + +extern const struct xattr_handler *gfs2_xattr_handlers_max[]; +extern const struct xattr_handler **gfs2_xattr_handlers_min;#endif /* __SUPER_DOT_H__ */ diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.cindex 9d7667bc4292..a860a144f3d4 100644 --- a/fs/gfs2/xattr.c +++ b/fs/gfs2/xattr.c @@ -70,6 +70,20 @@ static int ea_check_size(struct gfs2_sbd *sdp, unsigned int nsize, size_t dsize) return 0; }+bool gfs2_eatype_valid(struct gfs2_sbd *sdp, u8 type)This should be "static bool".
Ok, I'll update that.
+{ + switch(sdp->sd_sb.sb_fs_format) { + case GFS2_FS_FORMAT_MAX: + return true; + + case GFS2_FS_FORMAT_MIN: + return type <= GFS2_EATYPE_SECURITY; + + default: + return false; + } +} + typedef int (*ea_call_t) (struct gfs2_inode *ip, struct buffer_head *bh, struct gfs2_ea_header *ea, struct gfs2_ea_header *prev, void *private); @@ -77,6 +91,7 @@ typedef int (*ea_call_t) (struct gfs2_inode *ip, struct buffer_head *bh, static int ea_foreach_i(struct gfs2_inode *ip, struct buffer_head *bh, ea_call_t ea_call, void *data) { + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_ea_header *ea, *prev = NULL; int error = 0;@@ -89,9 +104,8 @@ static int ea_foreach_i(struct gfs2_inode *ip, structbuffer_head *bh, if (!(bh->b_data <= (char *)ea && (char *)GFS2_EA2NEXT(ea) <= bh->b_data + bh->b_size)) goto fail; - if (!GFS2_EATYPE_VALID(ea->ea_type)) + if (!gfs2_eatype_valid(sdp, ea->ea_type)) goto fail; - error = ea_call(ip, bh, ea, prev, data); if (error) return error; @@ -344,6 +358,7 @@ static int ea_list_i(struct gfs2_inode *ip, struct buffer_head *bh, struct gfs2_ea_header *ea, struct gfs2_ea_header *prev, void *private) { + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct ea_list *ei = private; struct gfs2_ea_request *er = ei->ei_er; unsigned int ea_size; @@ -353,6 +368,8 @@ static int ea_list_i(struct gfs2_inode *ip, struct buffer_head *bh, if (ea->ea_type == GFS2_EATYPE_UNUSED) return 0;+ BUG_ON(ea->ea_type > GFS2_EATYPE_SECURITY &&+ sdp->sd_sb.sb_fs_format == GFS2_FS_FORMAT_MIN); switch (ea->ea_type) { case GFS2_EATYPE_USR: prefix = "user."; @@ -366,8 +383,12 @@ static int ea_list_i(struct gfs2_inode *ip, struct buffer_head *bh, prefix = "security."; l = 9; break; + case GFS2_EATYPE_TRUSTED: + prefix = "trusted."; + l = 8; + break; default: - BUG(); + return 0; }ea_size = l + ea->ea_name_len + 1;@@ -1463,7 +1484,25 @@ static const struct xattr_handler gfs2_xattr_security_handler = { .set = gfs2_xattr_set, };-const struct xattr_handler *gfs2_xattr_handlers[] = {+static bool +gfs2_xattr_trusted_list(struct dentry *dentry) +{ + return capable(CAP_SYS_ADMIN); +} + +static const struct xattr_handler gfs2_xattr_trusted_handler = { + .prefix = XATTR_TRUSTED_PREFIX, + .flags = GFS2_EATYPE_TRUSTED, + .list = gfs2_xattr_trusted_list, + .get = gfs2_xattr_get, + .set = gfs2_xattr_set, +}; + +const struct xattr_handler *gfs2_xattr_handlers_max[] = { + /* GFS2_FS_FORMAT_MAX */ + &gfs2_xattr_trusted_handler, + + /* GFS2_FS_FORMAT_MIN */ &gfs2_xattr_user_handler, &gfs2_xattr_security_handler, &posix_acl_access_xattr_handler, @@ -1471,3 +1510,4 @@ const struct xattr_handler *gfs2_xattr_handlers[] = { NULL, };+const struct xattr_handler **gfs2_xattr_handlers_min =gfs2_xattr_handlers_max + 1; diff --git a/include/uapi/linux/gfs2_ondisk.h b/include/uapi/linux/gfs2_ondisk.h index 07e508e6691b..6ec4291bcc7a 100644 --- a/include/uapi/linux/gfs2_ondisk.h +++ b/include/uapi/linux/gfs2_ondisk.h @@ -47,7 +47,7 @@ #define GFS2_FORMAT_DE 1200 #define GFS2_FORMAT_QU 1500 /* These are part of the superblock */ -#define GFS2_FORMAT_FS 1801 +#define GFS2_FORMAT_FS 1802 #define GFS2_FORMAT_MULTI 1900/*@@ -389,8 +389,9 @@ struct gfs2_leaf { #define GFS2_EATYPE_USR 1 #define GFS2_EATYPE_SYS 2 #define GFS2_EATYPE_SECURITY 3 +#define GFS2_EATYPE_TRUSTED 4-#define GFS2_EATYPE_LAST 3+#define GFS2_EATYPE_LAST 4 #define GFS2_EATYPE_VALID(x) ((x) <= GFS2_EATYPE_LAST)GFS2_EATYPE_VALID was replaced by the function and isn't used elsewhere, so this line should be deleted. And if we do that, we might as well eliminate GFS2_EATYPE_LAST, or, alternately, use it in the new function.
I don't think we should remove things from gfs2_ondisk.h once they're in there, as it's a uapi header. GFS2_EATYPE_VALID is actually used in fsck.gfs2, but even if that was removed then we'd still want older gfs2-utils versions to compile against the latest kernel headers for bisecting etc.
Thanks, Andy
