The logic of whether filesystem can encode/decode file handles is open
coded in many places.
In preparation to changing the logic, move the open coded logic into
inline helpers.
Reviewed-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/exportfs/expfs.c | 8 ++------
fs/fhandle.c | 6 +-----
fs/nfsd/export.c | 3 +--
fs/notify/fanotify/fanotify_user.c | 4 ++--
fs/overlayfs/util.c | 2 +-
include/linux/exportfs.h | 27 +++++++++++++++++++++++++++
6 files changed, 34 insertions(+), 16 deletions(-)
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index c20704aa21b3..9ee205df8fa7 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -396,11 +396,7 @@ int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid,
{
const struct export_operations *nop = inode->i_sb->s_export_op;
- /*
- * If a decodeable file handle was requested, we need to make sure that
- * filesystem can decode file handles.
- */
- if (nop && !(flags & EXPORT_FH_FID) && !nop->fh_to_dentry)
+ if (!exportfs_can_encode_fh(nop, flags))
return -EOPNOTSUPP;
if (nop && nop->encode_fh)
@@ -456,7 +452,7 @@ exportfs_decode_fh_raw(struct vfsmount *mnt, struct fid *fid, int fh_len,
/*
* Try to get any dentry for the given file handle from the filesystem.
*/
- if (!nop || !nop->fh_to_dentry)
+ if (!exportfs_can_decode_fh(nop))
return ERR_PTR(-ESTALE);
result = nop->fh_to_dentry(mnt->mnt_sb, fid, fh_len, fileid_type);
if (IS_ERR_OR_NULL(result))
diff --git a/fs/fhandle.c b/fs/fhandle.c
index 6ea8d35a9382..18b3ba8dc8ea 100644
--- a/fs/fhandle.c
+++ b/fs/fhandle.c
@@ -26,12 +26,8 @@ static long do_sys_name_to_handle(const struct path *path,
/*
* We need to make sure whether the file system support decoding of
* the file handle if decodeable file handle was requested.
- * Otherwise, even empty export_operations are sufficient to opt-in
- * to encoding FIDs.
*/
- if (!path->dentry->d_sb->s_export_op ||
- (!(fh_flags & EXPORT_FH_FID) &&
- !path->dentry->d_sb->s_export_op->fh_to_dentry))
+ if (!exportfs_can_encode_fh(path->dentry->d_sb->s_export_op, fh_flags))
return -EOPNOTSUPP;
if (copy_from_user(&f_handle, ufh, sizeof(struct file_handle)))
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 11a0eaa2f914..dc99dfc1d411 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -421,8 +421,7 @@ static int check_export(struct path *path, int *flags, unsigned char *uuid)
return -EINVAL;
}
- if (!inode->i_sb->s_export_op ||
- !inode->i_sb->s_export_op->fh_to_dentry) {
+ if (!exportfs_can_decode_fh(inode->i_sb->s_export_op)) {
dprintk("exp_export: export of invalid fs type.\n");
return -EINVAL;
}
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 62fe0b679e58..0eb9622e8a9f 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -1595,7 +1595,7 @@ static int fanotify_test_fid(struct dentry *dentry, unsigned int flags)
* file handles so user can use name_to_handle_at() to compare fids
* reported with events to the file handle of watched objects.
*/
- if (!nop)
+ if (!exportfs_can_encode_fid(nop))
return -EOPNOTSUPP;
/*
@@ -1603,7 +1603,7 @@ static int fanotify_test_fid(struct dentry *dentry, unsigned int flags)
* supports decoding file handles, so user has a way to map back the
* reported fids to filesystem objects.
*/
- if (mark_type != FAN_MARK_INODE && !nop->fh_to_dentry)
+ if (mark_type != FAN_MARK_INODE && !exportfs_can_decode_fh(nop))
return -EOPNOTSUPP;
return 0;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 89e0d60d35b6..f0a712214ec2 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -55,7 +55,7 @@ int ovl_can_decode_fh(struct super_block *sb)
if (!capable(CAP_DAC_READ_SEARCH))
return 0;
- if (!sb->s_export_op || !sb->s_export_op->fh_to_dentry)
+ if (!exportfs_can_decode_fh(sb->s_export_op))
return 0;
return sb->s_export_op->encode_fh ? -1 : FILEID_INO32_GEN;
diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
index 11fbd0ee1370..5b3c9f30b422 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -233,6 +233,33 @@ extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid,
extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,
int *max_len, int flags);
+static inline bool exportfs_can_encode_fid(const struct export_operations *nop)
+{
+ return nop;
+}
+
+static inline bool exportfs_can_decode_fh(const struct export_operations *nop)
+{
+ return nop && nop->fh_to_dentry;
+}
+
+static inline bool exportfs_can_encode_fh(const struct export_operations *nop,
+ int fh_flags)
+{
+ /*
+ * If a non-decodeable file handle was requested, we only need to make
+ * sure that filesystem can encode file handles.
+ */
+ if (fh_flags & EXPORT_FH_FID)
+ return exportfs_can_encode_fid(nop);
+
+ /*
+ * If a decodeable file handle was requested, we need to make sure that
+ * filesystem can also decode file handles.
+ */
+ return exportfs_can_decode_fh(nop);
+}
+
static inline int exportfs_encode_fid(struct inode *inode, struct fid *fid,
int *max_len)
{
--
2.34.1
