[PATCH RFC 04/24] vfs: allow mkdir to wait for delegation break on parent

Jeff Layton
2024-03-15T16:53:19Z

In order to add directory delegation support, we need to break
delegations on the parent whenever there is going to be a change in the
directory.

Add a new delegated_inode parameter to vfs_mkdir. Most callers will set
that to NULL, but do_mkdirat can use that to wait for the delegation
break to complete and then retry.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
drivers/base/devtmpfs.c | 2 +-
fs/cachefiles/namei.c | 2 +-
fs/ecryptfs/inode.c | 2 +-
fs/init.c | 2 +-
fs/namei.c | 17 +++++++++++++----
fs/nfsd/nfs4recover.c | 2 +-
fs/nfsd/vfs.c | 2 +-
fs/overlayfs/overlayfs.h | 2 +-
fs/smb/server/vfs.c | 2 +-
include/linux/fs.h | 2 +-
10 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index b848764ef018..8d1dbcad69f7 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -166,7 +166,7 @@ static int dev_mkdir(const char *name, umode_t mode)
if (IS_ERR(dentry))
return PTR_ERR(dentry);

- err = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode);
+ err = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode, NULL);
if (!err)
/* mark as kernel-created inode */
d_inode(dentry)->i_private = &thread;
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 7ade836beb58..4e3e31320275 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -130,7 +130,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
goto mkdir_error;
ret = cachefiles_inject_write_error();
if (ret == 0)
- ret = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700);
+ ret = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700, NULL);
if (ret < 0) {
trace_cachefiles_vfs_error(NULL, d_inode(dir), ret,
cachefiles_trace_mkdir_error);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5ed1e4cf6c0b..d26b4484fa60 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -513,7 +513,7 @@ static int ecryptfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
rc = lock_parent(dentry, &lower_dentry, &lower_dir);
if (!rc)
rc = vfs_mkdir(&nop_mnt_idmap, lower_dir,
- lower_dentry, mode);
+ lower_dentry, mode, NULL);
if (rc || d_really_is_negative(lower_dentry))
goto out;
rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
diff --git a/fs/init.c b/fs/init.c
index e9387b6c4f30..325c9e4d9b20 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -232,7 +232,7 @@ int __init init_mkdir(const char *pathname, umode_t mode)
error = security_path_mkdir(&path, dentry, mode);
if (!error)
error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
- dentry, mode);
+ dentry, mode, NULL);
done_path_create(&path, dentry);
return error;
}
diff --git a/fs/namei.c b/fs/namei.c
index 56d3ebed7bac..6a22517f9938 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4103,7 +4103,7 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
* raw inode simply pass @nop_mnt_idmap.
*/
int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
- struct dentry *dentry, umode_t mode)
+ struct dentry *dentry, umode_t mode, struct inode **delegated_inode)
{
int error;
unsigned max_links = dir->i_sb->s_max_links;
@@ -4123,6 +4123,10 @@ int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
if (max_links && dir->i_nlink >= max_links)
return -EMLINK;

+ error = try_break_deleg(dir, delegated_inode);
+ if (error)
+ return error;
+
error = dir->i_op->mkdir(idmap, dir, dentry, mode);
if (!error)
fsnotify_mkdir(dir, dentry);
@@ -4136,6 +4140,7 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)
struct path path;
int error;
unsigned int lookup_flags = LOOKUP_DIRECTORY;
+ struct inode *delegated_inode = NULL;

retry:
dentry = filename_create(dfd, name, &path, lookup_flags);
@@ -4145,11 +4150,15 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)

error = security_path_mkdir(&path, dentry,
mode_strip_umask(path.dentry->d_inode, mode));
- if (!error) {
+ if (!error)
error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
- dentry, mode);
- }
+ dentry, mode, &delegated_inode);
done_path_create(&path, dentry);
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry;
+ }
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 2c060e0b1604..5bfced783a70 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -234,7 +234,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
* as well be forgiving and just succeed silently.
*/
goto out_put;
- status = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
+ status = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU, NULL);
out_put:
dput(dentry);
out_unlock:
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 6a4c506038e0..e42e58825590 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1496,7 +1496,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
nfsd_check_ignore_resizing(iap);
break;
case S_IFDIR:
- host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
+ host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode, NULL);
if (!host_err && unlikely(d_unhashed(dchild))) {
struct dentry *d;
d = lookup_one_len(dchild->d_name.name,
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index ee949f3e7c77..baa371947f86 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -242,7 +242,7 @@ static inline int ovl_do_mkdir(struct ovl_fs *ofs,
struct inode *dir, struct dentry *dentry,
umode_t mode)
{
- int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
+ int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, NULL);
pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
return err;
}
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index c487e834331a..3760e0dda349 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -227,7 +227,7 @@ int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)

idmap = mnt_idmap(path.mnt);
mode |= S_IFDIR;
- err = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode);
+ err = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode, NULL);
if (!err && d_unhashed(dentry)) {
struct dentry *d;

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8dfcddafdb3d..18eb7d628290 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1839,7 +1839,7 @@ bool inode_owner_or_capable(struct mnt_idmap *idmap,
int vfs_create(struct mnt_idmap *, struct inode *,
struct dentry *, umode_t, bool);
int vfs_mkdir(struct mnt_idmap *, struct inode *,
- struct dentry *, umode_t);
+ struct dentry *, umode_t, struct inode **);
int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
umode_t, dev_t);
int vfs_symlink(struct mnt_idmap *, struct inode *,

--
2.44.0