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.
Rename vfs_create as __vfs_create, make it static, and add a new
delegated_inode parameter. Fix do_mknodat to call __vfs_create and wait
for a delegation break if there is one. Add a new exported vfs_create
wrapper that passes in NULL for delegated_inode.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/namei.c | 55 ++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 36 insertions(+), 19 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 786f42bd184b5dbf6d754fa1fb6c94c0f75429f2..1427c53e13978e70adefdc572b71247536985430 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3458,6 +3458,32 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
return mode;
}
+static int __vfs_create(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode, bool want_excl,
+ struct inode **delegated_inode)
+{
+ int error;
+
+ error = may_create(idmap, dir, dentry);
+ if (error)
+ return error;
+
+ if (!dir->i_op->create)
+ return -EACCES; /* shouldn't it be ENOSYS? */
+
+ mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
+ error = security_inode_create(dir, dentry, mode);
+ if (error)
+ return error;
+ error = try_break_deleg(dir, delegated_inode);
+ if (error)
+ return error;
+ error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
+ if (!error)
+ fsnotify_create(dir, dentry);
+ return error;
+}
+
/**
* vfs_create - create new file
* @idmap: idmap of the mount the inode was found from
@@ -3477,23 +3503,7 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
int vfs_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool want_excl)
{
- int error;
-
- error = may_create(idmap, dir, dentry);
- if (error)
- return error;
-
- if (!dir->i_op->create)
- return -EACCES; /* shouldn't it be ENOSYS? */
-
- mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
- error = security_inode_create(dir, dentry, mode);
- if (error)
- return error;
- error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
- if (!error)
- fsnotify_create(dir, dentry);
- return error;
+ return __vfs_create(idmap, dir, dentry, mode, want_excl, NULL);
}
EXPORT_SYMBOL(vfs_create);
@@ -4365,6 +4375,7 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
struct path path;
int error;
unsigned int lookup_flags = 0;
+ struct inode *delegated_inode = NULL;
error = may_mknod(mode);
if (error)
@@ -4383,8 +4394,9 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
idmap = mnt_idmap(path.mnt);
switch (mode & S_IFMT) {
case 0: case S_IFREG:
- error = vfs_create(idmap, path.dentry->d_inode,
- dentry, mode, true);
+ error = __vfs_create(idmap, path.dentry->d_inode,
+ dentry, mode, true,
+ &delegated_inode);
if (!error)
security_path_post_mknod(idmap, dentry);
break;
@@ -4399,6 +4411,11 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
}
out2:
end_creating_path(&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;
--
2.51.0On Mon 13-10-25 10:48:05, Jeff Layton wrote:
> 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.
>
> Rename vfs_create as __vfs_create, make it static, and add a new
> delegated_inode parameter. Fix do_mknodat to call __vfs_create and wait
> for a delegation break if there is one. Add a new exported vfs_create
> wrapper that passes in NULL for delegated_inode.
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/namei.c | 55 ++++++++++++++++++++++++++++++++++++-------------------
> 1 file changed, 36 insertions(+), 19 deletions(-)
>
> diff --git a/fs/namei.c b/fs/namei.c
> index 786f42bd184b5dbf6d754fa1fb6c94c0f75429f2..1427c53e13978e70adefdc572b71247536985430 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -3458,6 +3458,32 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
> return mode;
> }
>
> +static int __vfs_create(struct mnt_idmap *idmap, struct inode *dir,
> + struct dentry *dentry, umode_t mode, bool want_excl,
> + struct inode **delegated_inode)
> +{
> + int error;
> +
> + error = may_create(idmap, dir, dentry);
> + if (error)
> + return error;
> +
> + if (!dir->i_op->create)
> + return -EACCES; /* shouldn't it be ENOSYS? */
> +
> + mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
> + error = security_inode_create(dir, dentry, mode);
> + if (error)
> + return error;
> + error = try_break_deleg(dir, delegated_inode);
> + if (error)
> + return error;
> + error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
> + if (!error)
> + fsnotify_create(dir, dentry);
> + return error;
> +}
> +
> /**
> * vfs_create - create new file
> * @idmap: idmap of the mount the inode was found from
> @@ -3477,23 +3503,7 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
> int vfs_create(struct mnt_idmap *idmap, struct inode *dir,
> struct dentry *dentry, umode_t mode, bool want_excl)
> {
> - int error;
> -
> - error = may_create(idmap, dir, dentry);
> - if (error)
> - return error;
> -
> - if (!dir->i_op->create)
> - return -EACCES; /* shouldn't it be ENOSYS? */
> -
> - mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
> - error = security_inode_create(dir, dentry, mode);
> - if (error)
> - return error;
> - error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
> - if (!error)
> - fsnotify_create(dir, dentry);
> - return error;
> + return __vfs_create(idmap, dir, dentry, mode, want_excl, NULL);
> }
> EXPORT_SYMBOL(vfs_create);
>
> @@ -4365,6 +4375,7 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
> struct path path;
> int error;
> unsigned int lookup_flags = 0;
> + struct inode *delegated_inode = NULL;
>
> error = may_mknod(mode);
> if (error)
> @@ -4383,8 +4394,9 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
> idmap = mnt_idmap(path.mnt);
> switch (mode & S_IFMT) {
> case 0: case S_IFREG:
> - error = vfs_create(idmap, path.dentry->d_inode,
> - dentry, mode, true);
> + error = __vfs_create(idmap, path.dentry->d_inode,
> + dentry, mode, true,
> + &delegated_inode);
> if (!error)
> security_path_post_mknod(idmap, dentry);
> break;
> @@ -4399,6 +4411,11 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
> }
> out2:
> end_creating_path(&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;
>
> --
> 2.51.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
On Mon, 2025-10-13 at 10:48 -0400, Jeff Layton wrote:
> 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.
>
> Rename vfs_create as __vfs_create, make it static, and add a new
> delegated_inode parameter. Fix do_mknodat to call __vfs_create and wait
> for a delegation break if there is one. Add a new exported vfs_create
> wrapper that passes in NULL for delegated_inode.
>
My apologies. I meant to change this to just add the extra parameter to
vfs_create() without all of the wrapper nonsense. I'll plan to re-post
at least once more, but I'll wait a bit in case there are other changes
needed.
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> fs/namei.c | 55 ++++++++++++++++++++++++++++++++++++-------------------
> 1 file changed, 36 insertions(+), 19 deletions(-)
>
> diff --git a/fs/namei.c b/fs/namei.c
> index 786f42bd184b5dbf6d754fa1fb6c94c0f75429f2..1427c53e13978e70adefdc572b71247536985430 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -3458,6 +3458,32 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
> return mode;
> }
>
> +static int __vfs_create(struct mnt_idmap *idmap, struct inode *dir,
> + struct dentry *dentry, umode_t mode, bool want_excl,
> + struct inode **delegated_inode)
> +{
> + int error;
> +
> + error = may_create(idmap, dir, dentry);
> + if (error)
> + return error;
> +
> + if (!dir->i_op->create)
> + return -EACCES; /* shouldn't it be ENOSYS? */
> +
> + mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
> + error = security_inode_create(dir, dentry, mode);
> + if (error)
> + return error;
> + error = try_break_deleg(dir, delegated_inode);
> + if (error)
> + return error;
> + error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
> + if (!error)
> + fsnotify_create(dir, dentry);
> + return error;
> +}
> +
> /**
> * vfs_create - create new file
> * @idmap: idmap of the mount the inode was found from
> @@ -3477,23 +3503,7 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
> int vfs_create(struct mnt_idmap *idmap, struct inode *dir,
> struct dentry *dentry, umode_t mode, bool want_excl)
> {
> - int error;
> -
> - error = may_create(idmap, dir, dentry);
> - if (error)
> - return error;
> -
> - if (!dir->i_op->create)
> - return -EACCES; /* shouldn't it be ENOSYS? */
> -
> - mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
> - error = security_inode_create(dir, dentry, mode);
> - if (error)
> - return error;
> - error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
> - if (!error)
> - fsnotify_create(dir, dentry);
> - return error;
> + return __vfs_create(idmap, dir, dentry, mode, want_excl, NULL);
> }
> EXPORT_SYMBOL(vfs_create);
>
> @@ -4365,6 +4375,7 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
> struct path path;
> int error;
> unsigned int lookup_flags = 0;
> + struct inode *delegated_inode = NULL;
>
> error = may_mknod(mode);
> if (error)
> @@ -4383,8 +4394,9 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
> idmap = mnt_idmap(path.mnt);
> switch (mode & S_IFMT) {
> case 0: case S_IFREG:
> - error = vfs_create(idmap, path.dentry->d_inode,
> - dentry, mode, true);
> + error = __vfs_create(idmap, path.dentry->d_inode,
> + dentry, mode, true,
> + &delegated_inode);
> if (!error)
> security_path_post_mknod(idmap, dentry);
> break;
> @@ -4399,6 +4411,11 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
> }
> out2:
> end_creating_path(&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;
--
Jeff Layton <jlayton@kernel.org>
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