Re: [PATCH 07/13] vfs: make vfs_create break delegations on parent directory
From: Jeff Layton <jlayton@kernel.org>
Date: 2025-10-13 20:33:27
Also in:
linux-cifs, linux-fsdevel, linux-nfs, linux-unionfs, linux-xfs, lkml, netfs
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.
quoted hunk ↗ jump to hunk
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 [off-list ref]