[patch 20/24] vfs: add path_link()

From: Miklos Szeredi
Date: Tue May 06 2008 - 05:22:37 EST


From: Miklos Szeredi <mszeredi@xxxxxxx>

Introduce path_link(). Make vfs_link() static.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
fs/ecryptfs/inode.c | 10 +++++-----
fs/namei.c | 26 ++++++++++++++++++--------
fs/nfsd/vfs.c | 14 ++++----------
include/linux/fs.h | 2 +-
4 files changed, 28 insertions(+), 24 deletions(-)

Index: linux-2.6/fs/ecryptfs/inode.c
===================================================================
--- linux-2.6.orig/fs/ecryptfs/inode.c 2008-05-06 11:04:40.000000000 +0200
+++ linux-2.6/fs/ecryptfs/inode.c 2008-05-06 11:04:40.000000000 +0200
@@ -379,7 +379,7 @@ static int ecryptfs_link(struct dentry *
{
struct dentry *lower_old_dentry;
struct dentry *lower_new_dentry;
- struct dentry *lower_dir_dentry;
+ struct path lower_dir;
u64 file_size_save;
int rc;

@@ -388,9 +388,9 @@ static int ecryptfs_link(struct dentry *
lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
dget(lower_old_dentry);
dget(lower_new_dentry);
- lower_dir_dentry = lock_parent(lower_new_dentry);
- rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
- lower_new_dentry);
+ lower_dir.mnt = ecryptfs_dentry_to_lower_mnt(new_dentry);
+ lower_dir.dentry = lock_parent(lower_new_dentry);
+ rc = path_link(lower_old_dentry, &lower_dir, lower_new_dentry);
if (rc || !lower_new_dentry->d_inode)
goto out_lock;
rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
@@ -402,7 +402,7 @@ static int ecryptfs_link(struct dentry *
ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
i_size_write(new_dentry->d_inode, file_size_save);
out_lock:
- unlock_dir(lower_dir_dentry);
+ unlock_dir(lower_dir.dentry);
dput(lower_new_dentry);
dput(lower_old_dentry);
d_drop(lower_old_dentry);
Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c 2008-05-06 11:04:40.000000000 +0200
+++ linux-2.6/fs/namei.c 2008-05-06 11:04:40.000000000 +0200
@@ -2514,7 +2514,7 @@ asmlinkage long sys_symlink(const char _
return sys_symlinkat(oldname, AT_FDCWD, newname);
}

-int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
+static int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
{
struct inode *inode = old_dentry->d_inode;
int error;
@@ -2552,6 +2552,22 @@ int vfs_link(struct dentry *old_dentry,
return error;
}

+int path_link(struct dentry *old_dentry, struct path *dir_path,
+ struct dentry *new_dentry)
+{
+ int error = mnt_want_write(dir_path->mnt);
+
+ if (!error) {
+ struct inode *dir = dir_path->dentry->d_inode;
+
+ error = vfs_link(old_dentry, dir, new_dentry);
+ mnt_drop_write(dir_path->mnt);
+ }
+
+ return error;
+}
+EXPORT_SYMBOL(path_link);
+
/*
* Hardlinks are often used in delicate situations. We avoid
* security-related surprises by not following symlinks on the
@@ -2592,12 +2608,7 @@ asmlinkage long sys_linkat(int olddfd, c
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
goto out_unlock;
- error = mnt_want_write(nd.path.mnt);
- if (error)
- goto out_dput;
- error = vfs_link(old_nd.path.dentry, nd.path.dentry->d_inode, new_dentry);
- mnt_drop_write(nd.path.mnt);
-out_dput:
+ error = path_link(old_nd.path.dentry, &nd.path, new_dentry);
dput(new_dentry);
out_unlock:
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
@@ -3017,7 +3028,6 @@ EXPORT_SYMBOL(vfs_permission);
EXPORT_SYMBOL(file_permission);
EXPORT_SYMBOL(unlock_rename);
EXPORT_SYMBOL(vfs_follow_link);
-EXPORT_SYMBOL(vfs_link);
EXPORT_SYMBOL(generic_permission);
EXPORT_SYMBOL(vfs_readlink);
EXPORT_SYMBOL(vfs_rename);
Index: linux-2.6/fs/nfsd/vfs.c
===================================================================
--- linux-2.6.orig/fs/nfsd/vfs.c 2008-05-06 11:04:40.000000000 +0200
+++ linux-2.6/fs/nfsd/vfs.c 2008-05-06 11:04:40.000000000 +0200
@@ -1586,8 +1586,9 @@ __be32
nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
char *name, int len, struct svc_fh *tfhp)
{
+ struct path dir_path;
struct dentry *ddir, *dnew, *dold;
- struct inode *dirp, *dest;
+ struct inode *dest;
__be32 err;
int host_err;

@@ -1607,7 +1608,6 @@ nfsd_link(struct svc_rqst *rqstp, struct

fh_lock_nested(ffhp, I_MUTEX_PARENT);
ddir = ffhp->fh_dentry;
- dirp = ddir->d_inode;

dnew = lookup_one_len(name, ddir, len);
host_err = PTR_ERR(dnew);
@@ -1617,12 +1617,8 @@ nfsd_link(struct svc_rqst *rqstp, struct
dold = tfhp->fh_dentry;
dest = dold->d_inode;

- host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt);
- if (host_err) {
- err = nfserrno(host_err);
- goto out_dput;
- }
- host_err = vfs_link(dold, dirp, dnew);
+ fh_to_path(ffhp, &dir_path);
+ host_err = path_link(dold, &dir_path, dnew);
if (!host_err) {
if (EX_ISSYNC(ffhp->fh_export)) {
err = nfserrno(nfsd_sync_dir(ddir));
@@ -1635,8 +1631,6 @@ nfsd_link(struct svc_rqst *rqstp, struct
else
err = nfserrno(host_err);
}
- mnt_drop_write(tfhp->fh_export->ex_path.mnt);
-out_dput:
dput(dnew);
out_unlock:
fh_unlock(ffhp);
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h 2008-05-06 11:04:40.000000000 +0200
+++ linux-2.6/include/linux/fs.h 2008-05-06 11:04:40.000000000 +0200
@@ -1128,7 +1128,7 @@ extern int path_create(struct path *, st
extern int path_mkdir(struct path *, struct dentry *, int);
extern int path_mknod(struct path *, struct dentry *, int, dev_t);
extern int path_symlink(struct path *, struct dentry *, const char *, int);
-extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
+extern int path_link(struct dentry *, struct path *, struct dentry *);
extern int path_rmdir(struct path *, struct dentry *);
extern int path_unlink(struct path *, struct dentry *);
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);

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