[PATCHv1 1/2] libfs: allow simple_fill_super() to add symlinks

From: David Vrabel
Date: Tue May 17 2016 - 06:28:10 EST


simple_fill_super() will add symlinks if an entry has mode & S_IFLNK.
The target is provided in the new "link" field.

Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
v2:
- simplified.
---
fs/libfs.c | 15 +++++++++++++--
include/linux/fs.h | 2 +-
2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index f3fa82c..5b3a391 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -517,9 +517,20 @@ int simple_fill_super(struct super_block *s, unsigned long magic,
dput(dentry);
goto out;
}
- inode->i_mode = S_IFREG | files->mode;
+ if (files->mode & S_IFLNK) {
+ inode->i_mode = files->mode;
+ inode->i_op = &simple_symlink_inode_operations;
+ inode->i_link = kstrdup(files->link, GFP_KERNEL);
+ if (!inode->i_link) {
+ iput(inode);
+ dput(dentry);
+ goto out;
+ }
+ } else {
+ inode->i_mode = S_IFREG | files->mode;
+ inode->i_fop = files->ops;
+ }
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
- inode->i_fop = files->ops;
inode->i_ino = i;
d_add(dentry, inode);
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 70e61b5..8a09998 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2897,7 +2897,7 @@ extern const struct file_operations simple_dir_operations;
extern const struct inode_operations simple_dir_inode_operations;
extern void make_empty_dir_inode(struct inode *inode);
extern bool is_empty_dir_inode(struct inode *inode);
-struct tree_descr { char *name; const struct file_operations *ops; int mode; };
+struct tree_descr { char *name; const struct file_operations *ops; int mode; char *link; };
struct dentry *d_alloc_name(struct dentry *, const char *);
extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
--
2.1.4