On Fri, Sep 13, 2024 at 12:15:23AM +0200, Pali Rohár wrote:
> Currently the directory restricted deletion flag (sticky bit, SVTX) is not
> mapped into NFS4 ACL by knfsd. Which means that the NFS4 ACL client is not
> aware of the fact that it cannot delete some files if the sticky bit is set
> on the server on parent directory. If the client copies sticky bit
> directory recursively to some other storage which implements the NFS4-like
> ACL (e.g. to NTFS filesystem or to SMB server) then the directory's
> restricted deletion flag is completely lost.
>
> This change aims to improve interoperability of the POSIX directory
> restricted deletion flag (sticky bit, SVTX) and NFS4 ACL structure in
> knfsd. It transparently maps POSIX directory's sticky bit into NFS4 ACL
> and vice-versa similarly like it already maps POSIX ACL into NFS4 ACL.
> It covers NFS4 GETATTR ACL, NFS4 SETATTR ACL, NFS4 CREATE+OPEN operations.
> When creating a new object over NFS4, it is possible to optionally specify
> NFS4 ACL, so this is covered too.
>
> For client SETATTR ACL, CREATE with ACL and OPEN-create with ACL
> operations, detection pattern for restricted deletion flag is ACE entry
> INHERIT_ONLY NO_PROPAGATE ALLOW OWNER@ DELETE together with check that
> nobody except the OWNER@ has DELETE_CHILD permission. Note that the OWNER@
> does not have to have DELETE_CHILD permission in case it does not have
> write access to directory.
>
> For client GETATTR ACL operation, when restricted deletion flag is present
> in inode, following ACE entries are prepended before any other ACEs:
>
> ALLOW OWNER@ DELETE_CHILD (1)
> DENY EVERYONE@ DELETE_CHILD
> INHERIT_ONLY NO_PROPAGATE DENY user_owner_of_dir DELETE (3)
> INHERIT_ONLY NO_PROPAGATE DENY OWNER@ DELETE (4)
> INHERIT_ONLY NO_PROPAGATE DENY user1 DELETE (ACL user1)
> ...
> INHERIT_ONLY NO_PROPAGATE DENY userN DELETE (ACL userN)
> INHERIT_ONLY NO_PROPAGATE ALLOW OWNER@ DELETE
>
> ACE entry (1) is present only when user OWNER@ has write access (can modify
> directory, including removing child entries), because it is possible to
> have sticky bit set also on read-only directory.
>
> ACE entry (3) is present only when user OWNER@ does not have write access
> (cannot modify directory) and it is required to override effect of the last
> ACE entry which allows child entry OWNER@ to remove entry itself. This is
> needed for example for POSIX mode 1577.
>
> ACE entry (4) is present only when anybody else except the directory owner
> has no write access to the directory. This is the case when sticky bit is
> set but nobody can use it because of missing directory write access. So
> this explicit DENY covers this edge case.
>
> ACE entries (ACL user1...userN) are for POSIX users which do not have write
> access to directory and therefore they cannot remove directory entries
> which they own. This is again needed for overriding the effect of the last
> ACE entry.
>
> When restricted deletion flag is not present then nothing is added.
>
> This is probably the best approximation of the directory restricted
> deletion flag. It covers directory's OWNER@ grant access, child OWNER@
> grant access and also restrictions for all other users. It also covers the
> situation when OWNER@ or some POSIX user does not have write access to the
> directory, and also covers situation when nobody except directory owner has
> write access to the directory.
>
> What this does not cover is the restriction when some POSIX group does not
> have directory write access, and another POSIX group has directory write
> access. This is probably not possible to express in NFS4 ACL language
> without ability to evaluate if user is member of some group or not. NFS4
> ACL in this case says for the owner of the file that the delete operation
> is allowed.
>
> The whole change is only about the mapping of the sticky bit into NFS4 ACL
> and only for NFS4 GET and SET ACL operations. It does not change any access
> permission checks.
>
> Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
> ---
> fs/nfsd/acl.h | 2 +-
> fs/nfsd/nfs4acl.c | 242 ++++++++++++++++++++++++++++++++++++++++++---
> fs/nfsd/nfs4proc.c | 31 +++++-
> 3 files changed, 255 insertions(+), 20 deletions(-)
>
> diff --git a/fs/nfsd/acl.h b/fs/nfsd/acl.h
> index 4b7324458a94..e7e7909bf03a 100644
> --- a/fs/nfsd/acl.h
> +++ b/fs/nfsd/acl.h
> @@ -48,6 +48,6 @@ __be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who);
> int nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
> struct nfs4_acl **acl);
> __be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl,
> - struct nfsd_attrs *attr);
> + struct nfsd_attrs *attr, int *dir_sticky);
>
> #endif /* LINUX_NFS4_ACL_H */
> diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
> index 96e786b5e544..6a53772c2a13 100644
> --- a/fs/nfsd/nfs4acl.c
> +++ b/fs/nfsd/nfs4acl.c
> @@ -46,6 +46,7 @@
> #define NFS4_ACL_TYPE_DEFAULT 0x01
> #define NFS4_ACL_DIR 0x02
> #define NFS4_ACL_OWNER 0x04
> +#define NFS4_ACL_DIR_STICKY 0x08
>
> /* mode bit translations: */
> #define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
> @@ -73,7 +74,7 @@ mask_from_posix(unsigned short perm, unsigned int flags)
> mask |= NFS4_READ_MODE;
> if (perm & ACL_WRITE)
> mask |= NFS4_WRITE_MODE;
> - if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
> + if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR) && !(flags & NFS4_ACL_DIR_STICKY))
> mask |= NFS4_ACE_DELETE_CHILD;
> if (perm & ACL_EXECUTE)
> mask |= NFS4_EXECUTE_MODE;
> @@ -89,7 +90,7 @@ deny_mask_from_posix(unsigned short perm, u32 flags)
> mask |= NFS4_READ_MODE;
> if (perm & ACL_WRITE)
> mask |= NFS4_WRITE_MODE;
> - if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
> + if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR) && !(flags & NFS4_ACL_DIR_STICKY))
> mask |= NFS4_ACE_DELETE_CHILD;
> if (perm & ACL_EXECUTE)
> mask |= NFS4_EXECUTE_MODE;
> @@ -110,7 +111,7 @@ low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
> {
> u32 write_mode = NFS4_WRITE_MODE;
>
> - if (flags & NFS4_ACL_DIR)
> + if ((flags & NFS4_ACL_DIR) && !(flags | NFS4_ACL_DIR_STICKY))
> write_mode |= NFS4_ACE_DELETE_CHILD;
> *mode = 0;
> if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
> @@ -123,7 +124,7 @@ low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
>
> static short ace2type(struct nfs4_ace *);
> static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
> - unsigned int);
> + unsigned int, kuid_t);
>
> int
> nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
> @@ -142,8 +143,11 @@ nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
> if (IS_ERR(pacl))
> return PTR_ERR(pacl);
>
> - /* allocate for worst case: one (deny, allow) pair each: */
> - size += 2 * pacl->a_count;
> + /*
> + * allocate for worst case: one (deny, allow) pair for each
> + * plus for restricted deletion flag (sticky bit): 4 + one for each
> + */
> + size += 2 * pacl->a_count + (4 + pacl->a_count);
>
> if (S_ISDIR(inode->i_mode)) {
> flags = NFS4_ACL_DIR;
> @@ -155,6 +159,10 @@ nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
>
> if (dpacl)
> size += 2 * dpacl->a_count;
> +
> + /* propagate restricted deletion flag (sticky bit) */
> + if (inode->i_mode & S_ISVTX)
> + flags |= NFS4_ACL_DIR_STICKY;
> }
>
> *acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
> @@ -164,10 +172,10 @@ nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
> }
> (*acl)->naces = 0;
>
> - _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
> + _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT, inode->i_uid);
>
> if (dpacl)
> - _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
> + _posix_to_nfsv4_one(dpacl, *acl, (flags | NFS4_ACL_TYPE_DEFAULT) & ~NFS4_ACL_DIR_STICKY, inode->i_uid);
>
> out:
> posix_acl_release(dpacl);
> @@ -231,7 +239,7 @@ summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
> /* We assume the acl has been verified with posix_acl_valid. */
> static void
> _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
> - unsigned int flags)
> + unsigned int flags, kuid_t owner_uid)
> {
> struct posix_acl_entry *pa, *group_owner_entry;
> struct nfs4_ace *ace;
> @@ -243,9 +251,149 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
> BUG_ON(pacl->a_count < 3);
> summarize_posix_acl(pacl, &pas);
>
> - pa = pacl->a_entries;
> ace = acl->aces + acl->naces;
>
> + /*
> + * Translate restricted deletion flag (sticky bit, SVTX) set on the
> + * directory to following NFS4 ACEs prepended before any other ACEs:
> + *
> + * ALLOW OWNER@ DELETE_CHILD (1)
> + * DENY EVERYONE@ DELETE_CHILD
> + * INHERIT_ONLY NO_PROPAGATE DENY user_owner_of_dir DELETE (3)
> + * INHERIT_ONLY NO_PROPAGATE DENY OWNER@ DELETE (4)
> + * INHERIT_ONLY NO_PROPAGATE DENY user1 DELETE (ACL user1)
> + * ...
> + * INHERIT_ONLY NO_PROPAGATE DENY userN DELETE (ACL userN)
> + * INHERIT_ONLY NO_PROPAGATE ALLOW OWNER@ DELETE
> + *
> + * (1) - only if user-owner has write access
> + * (3) - only if user-owner does not have write access
> + * (4) - only if non-user-owner does not have write access
> + * (ACL user1) - only if user1 does not have write access
> + * (ACL userN) - only if userN does not have write access
> + *
> + * These ACEs describe behavior of set restricted deletion flag (sticky
> + * bit) on directory as they allow only owner of individual child entries
> + * and owner of the directory to delete individual child entries.
> + * Everyone else is denied to remove child entries in this directory.
> + *
> + * For deleting entry in NFS4 ACL model it is needed either DELETE_CHILD
> + * permission (access mask) from the parent directory or DELETE permission
> + * (access mask) on the child. Just one of these two permissions is enough.
> + * So if there is explicit DENY DELETE_CHILD on the parent together with
> + * explicit ALLOW DELETE on the child, it means that deleting is allowed
> + * (evaluation of permissions is independent in NFS4 ACL model). OWNER@
> + * for inherited ACEs means owner of the child entry and not the owner
> + * of the parent from which was ACE inherited.
> + *
> + * This translation is imperfect just for a case when some group
> + * (including group-owner and others-group) does not have write access
> + * to directory. Handled is only the edge case (via rule 4) when
> + * everyone else except owner has no write access to the directory.
> + * This information is not present in NFS4 ACL because it looks like that
> + * this is not possible to express in this ACL model. So for ACL consumer
> + * it could look like that owner of the file can delete its own file even
> + * when group or other mode bits of the directory do not allow it.
> + */
> + if (flags & NFS4_ACL_DIR_STICKY) {
> + /*
> + * Explicitly allow directory owner to delete child entries
> + * if directory owner has write access
> + */
> + if (pas.owner & ACL_WRITE) {
> + ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
> + ace->flag = 0;
> + ace->access_mask = NFS4_ACE_DELETE_CHILD;
> + ace->whotype = NFS4_ACL_WHO_OWNER;
> + ace++;
> + acl->naces++;
> + }
> +
> + /*
> + * And then deny deleting child entries for all other users
> + * which do not have explicit DELETE permission granted by
> + * last rule in this section.
> + */
> + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
> + ace->flag = 0;
> + ace->access_mask = NFS4_ACE_DELETE_CHILD;
> + ace->whotype = NFS4_ACL_WHO_EVERYONE;
> + ace++;
> + acl->naces++;
> +
> + /*
> + * Do not grant directory owner to delete child entries (by the
> + * last rule in this section) if it does not have write access.
> + */
> + if (!(pas.owner & ACL_WRITE)) {
> + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
> + ace->flag = NFS4_INHERITANCE_FLAGS |
> + NFS4_ACE_INHERIT_ONLY_ACE |
> + NFS4_ACE_NO_PROPAGATE_INHERIT_ACE;
> + ace->access_mask = NFS4_ACE_DELETE;
> + ace->whotype = NFS4_ACL_WHO_NAMED;
> + ace->who_uid = owner_uid;
> + ace++;
> + acl->naces++;
> + }
> +
> + if (!(pas.users & ACL_WRITE) && !(pas.group & ACL_WRITE) &&
> + !(pas.groups & ACL_WRITE) && !(pas.other & ACL_WRITE)) {
> + /*
> + * Do not grant child owner who is not directory owner
> + * (handled by the first rule in this section) to
> + * delete own child entries if there is no possible
> + * directory write permission (checked for named users,
> + * group-owner, named groups and others-groups).
> + * This handles special edge case when only directory
> + * owner has write access to directory.
> + */
> + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
> + ace->flag = NFS4_INHERITANCE_FLAGS |
> + NFS4_ACE_INHERIT_ONLY_ACE |
> + NFS4_ACE_NO_PROPAGATE_INHERIT_ACE;
> + ace->access_mask = NFS4_ACE_DELETE;
> + ace->whotype = NFS4_ACL_WHO_OWNER;
> + ace++;
> + acl->naces++;
> + } else {
> + /*
> + * Do not grant individual named users to delete child
> + * entries (by the last rule in this section) if user
> + * does not have write access to directory.
> + */
> + for (pa = pacl->a_entries + 1; pa->e_tag == ACL_USER; pa++) {
> + if (pa->e_perm & pas.mask & ACL_WRITE)
> + continue;
> + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
> + ace->flag = NFS4_INHERITANCE_FLAGS |
> + NFS4_ACE_INHERIT_ONLY_ACE |
> + NFS4_ACE_NO_PROPAGATE_INHERIT_ACE;
> + ace->access_mask = NFS4_ACE_DELETE;
> + ace->whotype = NFS4_ACL_WHO_NAMED;
> + ace->who_uid = pa->e_uid;
> + ace++;
> + acl->naces++;
> + }
> + }
> +
> + /*
> + * Above rules filtered out users which do not have write access
> + * to the directory. Now allow child-owner to delete its own
> + * directory entries.
> + */
> + ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
> + ace->flag = NFS4_INHERITANCE_FLAGS |
> + NFS4_ACE_INHERIT_ONLY_ACE |
> + NFS4_ACE_NO_PROPAGATE_INHERIT_ACE;
> + ace->access_mask = NFS4_ACE_DELETE;
> + ace->whotype = NFS4_ACL_WHO_OWNER;
> + ace++;
> + acl->naces++;
> + }
> +
> + pa = pacl->a_entries;
> +
> /* We could deny everything not granted by the owner: */
> deny = ~pas.owner;
> /*
> @@ -517,7 +665,8 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
>
> pace = pacl->a_entries;
> pace->e_tag = ACL_USER_OBJ;
> - low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
> + /* owner is never affected by restricted deletion flag, so clear NFS4_ACL_DIR_STICKY */
> + low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags & ~NFS4_ACL_DIR_STICKY);
>
> for (i=0; i < state->users->n; i++) {
> pace++;
> @@ -691,9 +840,14 @@ static void process_one_v4_ace(struct posix_acl_state *state,
>
> static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
> struct posix_acl **pacl, struct posix_acl **dpacl,
> + int *dir_sticky,
> unsigned int flags)
> {
> struct posix_acl_state effective_acl_state, default_acl_state;
> + bool dir_allow_nonowner_delete_child = false;
> + bool dir_deny_everyone_delete_child = false;
> + bool dir_allow_child_owner_delete = false;
> + unsigned int eflags = 0;
> struct nfs4_ace *ace;
> int ret;
>
> @@ -705,6 +859,28 @@ static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
> goto out_estate;
> ret = -EINVAL;
> for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
> + /*
> + * Process and parse ACE entry INHERIT_ONLY NO_PROPAGATE DELETE
> + * for detecting restricted deletion flag (sticky bit). Allow
> + * SYNCHRONIZE access mask to be present as NFS4 clients can
> + * include this access mask together with any other one.
> + *
> + * It needs to be done before validation as NFS4_SUPPORTED_FLAGS
> + * does not contain NFS4_ACE_NO_PROPAGATE_INHERIT_ACE and this
> + * ACE must not throw error.
> + */
> + if ((flags & NFS4_ACL_DIR) &&
> + !(ace->flag & ~(NFS4_SUPPORTED_FLAGS|NFS4_ACE_NO_PROPAGATE_INHERIT_ACE)) &&
> + (ace->flag & NFS4_INHERITANCE_FLAGS) &&
> + (ace->flag & NFS4_ACE_INHERIT_ONLY_ACE) &&
> + (ace->flag & NFS4_ACE_NO_PROPAGATE_INHERIT_ACE) &&
> + (ace->access_mask & ~NFS4_ACE_SYNCHRONIZE) == NFS4_ACE_DELETE) {
> + if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
> + ace->whotype == NFS4_ACL_WHO_OWNER)
> + dir_allow_child_owner_delete = true;
> + continue;
> + }
> +
> if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
> ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
> goto out_dstate;
> @@ -725,6 +901,38 @@ static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
>
> if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
> process_one_v4_ace(&effective_acl_state, ace);
> +
> + /*
> + * Process and parse ACE entry with DELETE_CHILD access mask
> + * for detecting restricted deletion flag (sticky bit).
> + */
> + if ((flags & NFS4_ACL_DIR) &&
> + !(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE) &&
> + (ace->access_mask & NFS4_ACE_DELETE_CHILD)) {
> + if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
> + !dir_deny_everyone_delete_child &&
> + ace->whotype != NFS4_ACL_WHO_OWNER)
> + dir_allow_nonowner_delete_child = true;
> + else if (ace->type == NFS4_ACE_ACCESS_DENIED_ACE_TYPE &&
> + ace->whotype == NFS4_ACL_WHO_EVERYONE)
> + dir_deny_everyone_delete_child = true;
> + }
> + }
> +
> + /*
> + * Recognize restricted deletion flag (sticky bit) from directory ACL
> + * if ACEs on directory allow only owner of directory child entry to
> + * delete entry itself.
> + *
> + * This is relaxed check for rules generated by _posix_to_nfsv4_one().
> + * Relaxed check of restricted deletion flag is for security reasons
> + * and means that permissions would be more stricter, to prevent
> + * granting more access than what was specified in NFS4 ACL packet.
> + */
> + if (flags & NFS4_ACL_DIR) {
> + *dir_sticky = !dir_allow_nonowner_delete_child && dir_allow_child_owner_delete;
> + if (*dir_sticky)
> + eflags |= NFS4_ACL_DIR_STICKY;
> }
>
> /*
> @@ -750,7 +958,7 @@ static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
> default_acl_state.other = effective_acl_state.other;
> }
>
> - *pacl = posix_state_to_acl(&effective_acl_state, flags);
> + *pacl = posix_state_to_acl(&effective_acl_state, flags | eflags);
> if (IS_ERR(*pacl)) {
> ret = PTR_ERR(*pacl);
> *pacl = NULL;
> @@ -776,19 +984,23 @@ static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
> }
>
> __be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl,
> - struct nfsd_attrs *attr)
> + struct nfsd_attrs *attr, int *dir_sticky)
> {
> int host_error;
> unsigned int flags = 0;
>
> - if (!acl)
> + if (!acl) {
> + if (type == NF4DIR)
> + *dir_sticky = -1;
> return nfs_ok;
> + }
>
> if (type == NF4DIR)
> flags = NFS4_ACL_DIR;
>
> host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl,
> - &attr->na_dpacl, flags);
> + &attr->na_dpacl, dir_sticky,
> + flags);
> if (host_error == -EINVAL)
> return nfserr_attrnotsupp;
> else
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 0f67f4a7b8b2..56aeb745d108 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -259,7 +259,7 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
> return nfserrno(host_err);
>
> if (is_create_with_attrs(open))
> - nfsd4_acl_to_attr(NF4REG, open->op_acl, &attrs);
> + nfsd4_acl_to_attr(NF4REG, open->op_acl, &attrs, NULL);
>
> inode_lock_nested(inode, I_MUTEX_PARENT);
>
> @@ -791,6 +791,7 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> };
> struct svc_fh resfh;
> __be32 status;
> + int dir_sticky;
> dev_t rdev;
>
> fh_init(&resfh, NFS4_FHSIZE);
> @@ -804,7 +805,7 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> if (status)
> return status;
>
> - status = nfsd4_acl_to_attr(create->cr_type, create->cr_acl, &attrs);
> + status = nfsd4_acl_to_attr(create->cr_type, create->cr_acl, &attrs, &dir_sticky);
> current->fs->umask = create->cr_umask;
> switch (create->cr_type) {
> case NF4LNK:
> @@ -848,6 +849,11 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> break;
>
> case NF4DIR:
> + if (dir_sticky == 1) {
> + /* Set directory sticky bit deduced from the ACL attr. */
> + create->cr_iattr.ia_valid |= ATTR_MODE;
> + create->cr_iattr.ia_mode |= S_ISVTX;
> + }
> create->cr_iattr.ia_valid &= ~ATTR_SIZE;
> status = nfsd_create(rqstp, &cstate->current_fh,
> create->cr_name, create->cr_namelen,
> @@ -1144,6 +1150,7 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> struct inode *inode;
> __be32 status = nfs_ok;
> bool save_no_wcc;
> + int dir_sticky;
> int err;
>
> if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
> @@ -1165,10 +1172,26 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>
> inode = cstate->current_fh.fh_dentry->d_inode;
> status = nfsd4_acl_to_attr(S_ISDIR(inode->i_mode) ? NF4DIR : NF4REG,
> - setattr->sa_acl, &attrs);
> -
> + setattr->sa_acl, &attrs, &dir_sticky);
> if (status)
> goto out;
> +
> + if (S_ISDIR(inode->i_mode) && dir_sticky != -1 && !!(inode->i_mode & S_ISVTX) != dir_sticky) {
> + /*
> + * Set directory sticky bit deduced from the ACL attr.
> + * Do not clear sticky bit if it was explicitly set in MODE attr
> + * but was not deduced from ACL attr because clients can send
> + * both MODE and ACL attrs where sticky bit is only in MODE attr.
> + */
> + if (!(attrs.na_iattr->ia_valid & ATTR_MODE))
> + attrs.na_iattr->ia_mode = inode->i_mode;
> + if (dir_sticky)
> + attrs.na_iattr->ia_mode |= S_ISVTX;
> + else if (!(attrs.na_iattr->ia_valid & ATTR_MODE))
> + attrs.na_iattr->ia_mode &= ~S_ISVTX;
> + attrs.na_iattr->ia_valid |= ATTR_MODE;
> + }
> +
> save_no_wcc = cstate->current_fh.fh_no_wcc;
> cstate->current_fh.fh_no_wcc = true;
> status = nfsd_setattr(rqstp, &cstate->current_fh, &attrs, NULL);
> --
> 2.20.1
>
Hi Pali -
Apologies for the delayed response.
Being somewhat un-expert in things ACL, I'm not sure if this is the
correct approach, or if it's right for the POSIX ACL-only
implementation we have in Linux. I'm going to research this a bit
and get back to you.
--
Chuck Lever
