Re: [PATCH 01/13] filelock: push the S_ISREG check down to ->setlease handlers
From: NeilBrown <hidden>
Date: 2025-10-14 05:37:40
Also in:
linux-cifs, linux-fsdevel, linux-nfs, linux-unionfs, linux-xfs, lkml, netfs
On Tue, 14 Oct 2025, Jeff Layton wrote:
When nfsd starts requesting directory delegations, setlease handlers may see requests for leases on directories. Push the !S_ISREG check down into the non-trivial setlease handlers, so we can selectively enable them where they're supported. FUSE is special: It's the only filesystem that supports atomic_open and allows kernel-internal leases. Ensure that we don't allow directory leases by default going forward by explicitly disabling them there.
What is special about atomic_open w.r.t leases? Thanks, NeilBrown
quoted hunk ↗ jump to hunk
Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/fuse/dir.c | 1 + fs/locks.c | 5 +++-- fs/nfs/nfs4file.c | 2 ++ fs/smb/client/cifsfs.c | 3 +++ 4 files changed, 9 insertions(+), 2 deletions(-)diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index ecaec0fea3a132e7cbb88121e7db7fb504d57d3c..667774cc72a1d49796f531fcb342d2e4878beb85 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c@@ -2230,6 +2230,7 @@ static const struct file_operations fuse_dir_operations = { .fsync = fuse_dir_fsync, .unlocked_ioctl = fuse_dir_ioctl, .compat_ioctl = fuse_dir_compat_ioctl, + .setlease = simple_nosetlease, }; static const struct inode_operations fuse_common_inode_operations = {diff --git a/fs/locks.c b/fs/locks.c index 04a3f0e2072461b6e2d3d1cd12f2b089d69a7db3..0b16921fb52e602ea2e0c3de39d9d772af98ba7d 100644 --- a/fs/locks.c +++ b/fs/locks.c@@ -1929,6 +1929,9 @@ static int generic_delete_lease(struct file *filp, void *owner) int generic_setlease(struct file *filp, int arg, struct file_lease **flp, void **priv) { + if (!S_ISREG(file_inode(filp)->i_mode)) + return -EINVAL; + switch (arg) { case F_UNLCK: return generic_delete_lease(filp, *priv);@@ -2018,8 +2021,6 @@ vfs_setlease(struct file *filp, int arg, struct file_lease **lease, void **priv) if ((!vfsuid_eq_kuid(vfsuid, current_fsuid())) && !capable(CAP_LEASE)) return -EACCES; - if (!S_ISREG(inode->i_mode)) - return -EINVAL; error = security_file_lock(filp, arg); if (error) return error;diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c index 7f43e890d3564a000dab9365048a3e17dc96395c..7317f26892c5782a39660cae87ec1afea24e36c0 100644 --- a/fs/nfs/nfs4file.c +++ b/fs/nfs/nfs4file.c@@ -431,6 +431,8 @@ void nfs42_ssc_unregister_ops(void) static int nfs4_setlease(struct file *file, int arg, struct file_lease **lease, void **priv) { + if (!S_ISREG(file_inode(file)->i_mode)) + return -EINVAL; return nfs4_proc_setlease(file, arg, lease, priv); }diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c index 05b1fa76e8ccf1e86f0c174593cd6e1acb84608d..03c44c1d9bb631b87a8b67aa16e481d6bb3c7d14 100644 --- a/fs/smb/client/cifsfs.c +++ b/fs/smb/client/cifsfs.c@@ -1149,6 +1149,9 @@ cifs_setlease(struct file *file, int arg, struct file_lease **lease, void **priv struct inode *inode = file_inode(file); struct cifsFileInfo *cfile = file->private_data; + if (!S_ISREG(inode->i_mode)) + return -EINVAL; + /* Check if file is oplocked if this is request for new lease */ if (arg == F_UNLCK || ((arg == F_RDLCK) && CIFS_CACHE_READ(CIFS_I(inode))) ||-- 2.51.0