[PATCH 04/13] vfs: add renameat2 syscall
From: Miklos Szeredi
Date: Fri Feb 07 2014 - 11:56:07 EST
From: Miklos Szeredi <mszeredi@xxxxxxx>
Add new renameat2 syscall, which is the same as renameat with an added
flags argument.
Pass flags to vfs_rename() and to i_op->rename() as well.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
Documentation/filesystems/Locking | 6 +++-
Documentation/filesystems/vfs.txt | 16 ++++++++++
arch/x86/syscalls/syscall_64.tbl | 1 +
.../lustre/lustre/include/linux/lustre_compat25.h | 4 +--
drivers/staging/lustre/lustre/lvfs/lvfs_linux.c | 2 +-
fs/cachefiles/namei.c | 2 +-
fs/ecryptfs/inode.c | 2 +-
fs/namei.c | 34 +++++++++++++++++-----
fs/nfsd/vfs.c | 2 +-
include/linux/fs.h | 4 ++-
10 files changed, 58 insertions(+), 15 deletions(-)
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 5b0c083d7c0e..f424e0e5b46b 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -47,6 +47,8 @@ prototypes:
int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
int (*rename) (struct inode *, struct dentry *,
struct inode *, struct dentry *);
+ int (*rename2) (struct inode *, struct dentry *,
+ struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
void * (*follow_link) (struct dentry *, struct nameidata *);
void (*put_link) (struct dentry *, struct nameidata *, void *);
@@ -78,6 +80,7 @@ mkdir: yes
unlink: yes (both)
rmdir: yes (both) (see below)
rename: yes (all) (see below)
+rename2: yes (all) (see below)
readlink: no
follow_link: no
put_link: no
@@ -96,7 +99,8 @@ tmpfile: no
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
victim.
- cross-directory ->rename() has (per-superblock) ->s_vfs_rename_sem.
+ cross-directory ->rename() and rename2() has (per-superblock)
+->s_vfs_rename_sem.
See Documentation/filesystems/directory-locking for more detailed discussion
of the locking scheme for directory operations.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index c53784c119c8..94eb86287bcb 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -347,6 +347,8 @@ struct inode_operations {
int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
int (*rename) (struct inode *, struct dentry *,
struct inode *, struct dentry *);
+ int (*rename2) (struct inode *, struct dentry *,
+ struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
void * (*follow_link) (struct dentry *, struct nameidata *);
void (*put_link) (struct dentry *, struct nameidata *, void *);
@@ -414,6 +416,20 @@ otherwise noted.
rename: called by the rename(2) system call to rename the object to
have the parent and name given by the second inode and dentry.
+ rename2: this has an additional flags argument compared to rename.
+ If no flags are supported by the filesystem then this method
+ need not be implemented. If some flags are supported then the
+ filesystem must return -EINVAL for any unsupported or unknown
+ flags. Currently the following flags are implemented:
+ (1) RENAME_NOREPLACE: this flag indicates that if the target
+ of the rename exists the rename should fail with -EEXIST
+ instead of replacing the target. The VFS already checks for
+ existence, so for local filesystems the RENAME_NOREPLACE
+ implementation is equivalent to plain rename.
+ (2) RENAME_EXCHANGE: exchange source and target. Both must
+ exist; this is checked by the VFS. Unlike plain rename,
+ source and target may be of different type.
+
readlink: called by the readlink(2) system call. Only required if
you want to support reading symbolic links
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index a12bddc7ccea..04376ac3d9ef 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -322,6 +322,7 @@
313 common finit_module sys_finit_module
314 common sched_setattr sys_sched_setattr
315 common sched_getattr sys_sched_getattr
+316 common renameat2 sys_renameat2
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/drivers/staging/lustre/lustre/include/linux/lustre_compat25.h b/drivers/staging/lustre/lustre/include/linux/lustre_compat25.h
index eefdb8d061b1..81cc7a0134bb 100644
--- a/drivers/staging/lustre/lustre/include/linux/lustre_compat25.h
+++ b/drivers/staging/lustre/lustre/include/linux/lustre_compat25.h
@@ -105,8 +105,8 @@ static inline void ll_set_fs_pwd(struct fs_struct *fs, struct vfsmount *mnt,
#define ll_vfs_unlink(inode,entry,mnt) vfs_unlink(inode,entry)
#define ll_vfs_mknod(dir,entry,mnt,mode,dev) vfs_mknod(dir,entry,mode,dev)
#define ll_security_inode_unlink(dir,entry,mnt) security_inode_unlink(dir,entry)
-#define ll_vfs_rename(old,old_dir,mnt,new,new_dir,mnt1,delegated_inode) \
- vfs_rename(old,old_dir,new,new_dir,delegated_inode)
+#define ll_vfs_rename(old, old_dir, mnt, new, new_dir, mnt1) \
+ vfs_rename(old, old_dir, new, new_dir, NULL, 0)
#define cfs_bio_io_error(a,b) bio_io_error((a))
#define cfs_bio_endio(a,b,c) bio_endio((a),(c))
diff --git a/drivers/staging/lustre/lustre/lvfs/lvfs_linux.c b/drivers/staging/lustre/lustre/lvfs/lvfs_linux.c
index 428ffd8c37b7..d50822be3230 100644
--- a/drivers/staging/lustre/lustre/lvfs/lvfs_linux.c
+++ b/drivers/staging/lustre/lustre/lvfs/lvfs_linux.c
@@ -223,7 +223,7 @@ int lustre_rename(struct dentry *dir, struct vfsmount *mnt,
GOTO(put_old, err = PTR_ERR(dchild_new));
err = ll_vfs_rename(dir->d_inode, dchild_old, mnt,
- dir->d_inode, dchild_new, mnt, NULL);
+ dir->d_inode, dchild_new, mnt);
dput(dchild_new);
put_old:
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index ca65f39dc8dc..31088a969351 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -396,7 +396,7 @@ try_again:
cachefiles_io_error(cache, "Rename security error %d", ret);
} else {
ret = vfs_rename(dir->d_inode, rep,
- cache->graveyard->d_inode, grave, NULL);
+ cache->graveyard->d_inode, grave, NULL, 0);
if (ret != 0 && ret != -ENOMEM)
cachefiles_io_error(cache,
"Rename failed with error %d", ret);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index b167ca48b8ee..d4a9431ec73c 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -641,7 +641,7 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
}
rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry,
- NULL);
+ NULL, 0);
if (rc)
goto out_lock;
if (target_inode)
diff --git a/fs/namei.c b/fs/namei.c
index b6976bd59cbb..93a98a303db5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3953,6 +3953,7 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
* @new_dir: parent of destination
* @new_dentry: destination
* @delegated_inode: returns an inode needing a delegation break
+ * @flags: rename flags
*
* The caller must hold multiple mutexes--see lock_rename()).
*
@@ -3996,7 +3997,7 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
*/
int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
- struct inode **delegated_inode)
+ struct inode **delegated_inode, unsigned int flags)
{
int error;
bool is_dir = d_is_dir(old_dentry);
@@ -4021,6 +4022,9 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (!old_dir->i_op->rename)
return -EPERM;
+ if (flags && !old_dir->i_op->rename2)
+ return -EINVAL;
+
/*
* If we are going to change the parent - check write permissions,
* we'll need to flip '..'.
@@ -4066,7 +4070,13 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
goto out;
}
}
- error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
+ if (!flags) {
+ error = old_dir->i_op->rename(old_dir, old_dentry,
+ new_dir, new_dentry);
+ } else {
+ error = old_dir->i_op->rename2(old_dir, old_dentry,
+ new_dir, new_dentry, flags);
+ }
if (error)
goto out;
@@ -4091,8 +4101,8 @@ out:
return error;
}
-SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
- int, newdfd, const char __user *, newname)
+SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
+ int, newdfd, const char __user *, newname, unsigned int, flags)
{
struct dentry *old_dir, *new_dir;
struct dentry *old_dentry, *new_dentry;
@@ -4104,6 +4114,10 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
unsigned int lookup_flags = 0;
bool should_retry = false;
int error;
+
+ if (flags)
+ return -EINVAL;
+
retry:
from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
if (IS_ERR(from)) {
@@ -4175,8 +4189,8 @@ retry_deleg:
if (error)
goto exit5;
error = vfs_rename(old_dir->d_inode, old_dentry,
- new_dir->d_inode, new_dentry,
- &delegated_inode);
+ new_dir->d_inode, new_dentry,
+ &delegated_inode, flags);
exit5:
dput(new_dentry);
exit4:
@@ -4206,9 +4220,15 @@ exit:
return error;
}
+SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
+ int, newdfd, const char __user *, newname)
+{
+ return sys_renameat2(olddfd, oldname, newdfd, newname, 0);
+}
+
SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname)
{
- return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname);
+ return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
}
int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 017d3cb5e99b..f88df9c1336d 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1693,7 +1693,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
goto out_dput_new;
- host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL);
+ host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
if (!host_err) {
host_err = commit_metadata(tfhp);
if (!host_err)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 09f553c59813..4fbdfae87410 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1456,7 +1456,7 @@ extern int vfs_symlink(struct inode *, struct dentry *, const char *);
extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
extern int vfs_rmdir(struct inode *, struct dentry *);
extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
-extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **);
+extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
/*
* VFS dentry helper functions.
@@ -1567,6 +1567,8 @@ struct inode_operations {
int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
int (*rename) (struct inode *, struct dentry *,
struct inode *, struct dentry *);
+ int (*rename2) (struct inode *, struct dentry *,
+ struct inode *, struct dentry *, unsigned int);
int (*setattr) (struct dentry *, struct iattr *);
int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
--
1.8.1.4
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