| Message ID | 20231129-idmap-fscap-refactor-v1-12-da5a26058a5b@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: use type-safe uid representation for filesystem capabilities | expand |
On Wed, Nov 29, 2023 at 11:50 PM Seth Forshee (DigitalOcean) <sforshee@kernel.org> wrote: > > Using vfs_{get,set}xattr() for fscaps will be blocked in a future > commit, so convert ovl to use the new interfaces. Also remove the now > unused ovl_getxattr_value(). > > Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> You may add: Reviewed-by: Amir Goldstein <amir73il@gmail.com> I am assuming that this work is destined to be merged via the vfs tree? Note that there is already a (non-conflicting) patch to copy_up.c on Christian's vfs.rw branch. I think it is best that all the overlayfs patches are tested together by the vfs maintainer in preparation for the 6.8 merge window, so I have a feeling that the 6.8 overlayfs PR is going to be merged via the vfs tree ;-) Thanks, Amir. > --- > fs/overlayfs/copy_up.c | 72 ++++++++++++++++++++++++++------------------------ > 1 file changed, 37 insertions(+), 35 deletions(-) > > diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c > index 4382881b0709..b43af5ce4b21 100644 > --- a/fs/overlayfs/copy_up.c > +++ b/fs/overlayfs/copy_up.c > @@ -73,6 +73,23 @@ static int ovl_copy_acl(struct ovl_fs *ofs, const struct path *path, > return err; > } > > +static int ovl_copy_fscaps(struct ovl_fs *ofs, const struct path *oldpath, > + struct dentry *new) > +{ > + struct vfs_caps capability; > + int err; > + > + err = vfs_get_fscaps(mnt_idmap(oldpath->mnt), oldpath->dentry, > + &capability); > + if (err) { > + if (err == -ENODATA || err == -EOPNOTSUPP) > + return 0; > + return err; > + } > + > + return vfs_set_fscaps(ovl_upper_mnt_idmap(ofs), new, &capability, 0); > +} > + > int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct dentry *new) > { > struct dentry *old = oldpath->dentry; > @@ -130,6 +147,14 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de > break; > } > > + if (!strcmp(name, XATTR_NAME_CAPS)) { > + error = ovl_copy_fscaps(OVL_FS(sb), oldpath, new); > + if (!error) > + continue; > + /* fs capabilities must be copied */ > + break; > + } > + > retry: > size = ovl_do_getxattr(oldpath, name, value, value_size); > if (size == -ERANGE) > @@ -1006,61 +1031,40 @@ static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, > return true; > } > > -static ssize_t ovl_getxattr_value(const struct path *path, char *name, char **value) > -{ > - ssize_t res; > - char *buf; > - > - res = ovl_do_getxattr(path, name, NULL, 0); > - if (res == -ENODATA || res == -EOPNOTSUPP) > - res = 0; > - > - if (res > 0) { > - buf = kzalloc(res, GFP_KERNEL); > - if (!buf) > - return -ENOMEM; > - > - res = ovl_do_getxattr(path, name, buf, res); > - if (res < 0) > - kfree(buf); > - else > - *value = buf; > - } > - return res; > -} > - > /* Copy up data of an inode which was copied up metadata only in the past. */ > static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) > { > struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); > struct path upperpath; > int err; > - char *capability = NULL; > - ssize_t cap_size; > + struct vfs_caps capability; > + bool has_capability = false; > > ovl_path_upper(c->dentry, &upperpath); > if (WARN_ON(upperpath.dentry == NULL)) > return -EIO; > > if (c->stat.size) { > - err = cap_size = ovl_getxattr_value(&upperpath, XATTR_NAME_CAPS, > - &capability); > - if (cap_size < 0) > + err = vfs_get_fscaps(mnt_idmap(upperpath.mnt), upperpath.dentry, > + &capability); > + if (!err) > + has_capability = 1; > + else if (err != -ENODATA && err != EOPNOTSUPP) > goto out; > } > > err = ovl_copy_up_data(c, &upperpath); > if (err) > - goto out_free; > + goto out; > > /* > * Writing to upper file will clear security.capability xattr. We > * don't want that to happen for normal copy-up operation. > */ > ovl_start_write(c->dentry); > - if (capability) { > - err = ovl_do_setxattr(ofs, upperpath.dentry, XATTR_NAME_CAPS, > - capability, cap_size, 0); > + if (has_capability) { > + err = vfs_set_fscaps(mnt_idmap(upperpath.mnt), upperpath.dentry, > + &capability, 0); > } > if (!err) { > err = ovl_removexattr(ofs, upperpath.dentry, > @@ -1068,13 +1072,11 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) > } > ovl_end_write(c->dentry); > if (err) > - goto out_free; > + goto out; > > ovl_clear_flag(OVL_HAS_DIGEST, d_inode(c->dentry)); > ovl_clear_flag(OVL_VERIFIED_DIGEST, d_inode(c->dentry)); > ovl_set_upperdata(d_inode(c->dentry)); > -out_free: > - kfree(capability); > out: > return err; > } > > -- > 2.43.0 >
On Thu, Nov 30, 2023 at 08:23:28AM +0200, Amir Goldstein wrote: > On Wed, Nov 29, 2023 at 11:50 PM Seth Forshee (DigitalOcean) > <sforshee@kernel.org> wrote: > > > > Using vfs_{get,set}xattr() for fscaps will be blocked in a future > > commit, so convert ovl to use the new interfaces. Also remove the now > > unused ovl_getxattr_value(). > > > > Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> > > You may add: > > Reviewed-by: Amir Goldstein <amir73il@gmail.com> Thanks! > I am assuming that this work is destined to be merged via the vfs tree? > Note that there is already a (non-conflicting) patch to copy_up.c on > Christian's vfs.rw branch. I'll leave that up to Christian. There are also other mnt_idmapping.h changes on vfs.misc which could cause (probably minor) conflicts.
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 4382881b0709..b43af5ce4b21 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -73,6 +73,23 @@ static int ovl_copy_acl(struct ovl_fs *ofs, const struct path *path, return err; } +static int ovl_copy_fscaps(struct ovl_fs *ofs, const struct path *oldpath, + struct dentry *new) +{ + struct vfs_caps capability; + int err; + + err = vfs_get_fscaps(mnt_idmap(oldpath->mnt), oldpath->dentry, + &capability); + if (err) { + if (err == -ENODATA || err == -EOPNOTSUPP) + return 0; + return err; + } + + return vfs_set_fscaps(ovl_upper_mnt_idmap(ofs), new, &capability, 0); +} + int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct dentry *new) { struct dentry *old = oldpath->dentry; @@ -130,6 +147,14 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de break; } + if (!strcmp(name, XATTR_NAME_CAPS)) { + error = ovl_copy_fscaps(OVL_FS(sb), oldpath, new); + if (!error) + continue; + /* fs capabilities must be copied */ + break; + } + retry: size = ovl_do_getxattr(oldpath, name, value, value_size); if (size == -ERANGE) @@ -1006,61 +1031,40 @@ static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, return true; } -static ssize_t ovl_getxattr_value(const struct path *path, char *name, char **value) -{ - ssize_t res; - char *buf; - - res = ovl_do_getxattr(path, name, NULL, 0); - if (res == -ENODATA || res == -EOPNOTSUPP) - res = 0; - - if (res > 0) { - buf = kzalloc(res, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - res = ovl_do_getxattr(path, name, buf, res); - if (res < 0) - kfree(buf); - else - *value = buf; - } - return res; -} - /* Copy up data of an inode which was copied up metadata only in the past. */ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) { struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); struct path upperpath; int err; - char *capability = NULL; - ssize_t cap_size; + struct vfs_caps capability; + bool has_capability = false; ovl_path_upper(c->dentry, &upperpath); if (WARN_ON(upperpath.dentry == NULL)) return -EIO; if (c->stat.size) { - err = cap_size = ovl_getxattr_value(&upperpath, XATTR_NAME_CAPS, - &capability); - if (cap_size < 0) + err = vfs_get_fscaps(mnt_idmap(upperpath.mnt), upperpath.dentry, + &capability); + if (!err) + has_capability = 1; + else if (err != -ENODATA && err != EOPNOTSUPP) goto out; } err = ovl_copy_up_data(c, &upperpath); if (err) - goto out_free; + goto out; /* * Writing to upper file will clear security.capability xattr. We * don't want that to happen for normal copy-up operation. */ ovl_start_write(c->dentry); - if (capability) { - err = ovl_do_setxattr(ofs, upperpath.dentry, XATTR_NAME_CAPS, - capability, cap_size, 0); + if (has_capability) { + err = vfs_set_fscaps(mnt_idmap(upperpath.mnt), upperpath.dentry, + &capability, 0); } if (!err) { err = ovl_removexattr(ofs, upperpath.dentry, @@ -1068,13 +1072,11 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) } ovl_end_write(c->dentry); if (err) - goto out_free; + goto out; ovl_clear_flag(OVL_HAS_DIGEST, d_inode(c->dentry)); ovl_clear_flag(OVL_VERIFIED_DIGEST, d_inode(c->dentry)); ovl_set_upperdata(d_inode(c->dentry)); -out_free: - kfree(capability); out: return err; }
Using vfs_{get,set}xattr() for fscaps will be blocked in a future commit, so convert ovl to use the new interfaces. Also remove the now unused ovl_getxattr_value(). Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> --- fs/overlayfs/copy_up.c | 72 ++++++++++++++++++++++++++------------------------ 1 file changed, 37 insertions(+), 35 deletions(-)