Commit 7df93452 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull renameat2 system call from Miklos Szeredi:
 "This adds a new syscall, renameat2(), which is the same as renameat()
  but with a flags argument.

  The purpose of extending rename is to add cross-rename, a symmetric
  variant of rename, which exchanges the two files.  This allows
  interesting things, which were not possible before, for example
  atomically replacing a directory tree with a symlink, etc...  This
  also allows overlayfs and friends to operate on whiteouts atomically.

  Andy Lutomirski also suggested a "noreplace" flag, which disables the
  overwriting behavior of rename.

  These two flags, RENAME_EXCHANGE and RENAME_NOREPLACE are only
  implemented for ext4 as an example and for testing"

* 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ext4: add cross rename support
  ext4: rename: split out helper functions
  ext4: rename: move EMLINK check up
  ext4: rename: create ext4_renament structure for local vars
  vfs: add cross-rename
  vfs: lock_two_nondirectories: allow directory args
  security: add flags to rename hooks
  vfs: add RENAME_NOREPLACE flag
  vfs: add renameat2 syscall
  vfs: rename: use common code for dir and non-dir
  vfs: rename: move d_move() up
  vfs: add d_is_dir()
parents 3c83e61e bd42998a
......@@ -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.
......
......@@ -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
......
......@@ -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
......
......@@ -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))
......
......@@ -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:
......
......@@ -391,12 +391,12 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
path.dentry = dir;
path_to_graveyard.mnt = cache->mnt;
path_to_graveyard.dentry = cache->graveyard;
ret = security_path_rename(&path, rep, &path_to_graveyard, grave);
ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0);
if (ret < 0) {
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);
......
......@@ -2483,12 +2483,14 @@ static void switch_names(struct dentry *dentry, struct dentry *target)
dentry->d_name.name = dentry->d_iname;
} else {
/*
* Both are internal. Just copy target to dentry
* Both are internal.
*/
memcpy(dentry->d_iname, target->d_name.name,
target->d_name.len + 1);
dentry->d_name.len = target->d_name.len;
return;
unsigned int i;
BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long)));
for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) {
swap(((long *) &dentry->d_iname)[i],
((long *) &target->d_iname)[i]);
}
}
}
swap(dentry->d_name.len, target->d_name.len);
......@@ -2545,13 +2547,15 @@ static void dentry_unlock_parents_for_move(struct dentry *dentry,
* __d_move - move a dentry
* @dentry: entry to move
* @target: new dentry
* @exchange: exchange the two dentries
*
* Update the dcache to reflect the move of a file name. Negative
* dcache entries should not be moved in this way. Caller must hold
* rename_lock, the i_mutex of the source and target directories,
* and the sb->s_vfs_rename_mutex if they differ. See lock_rename().
*/
static void __d_move(struct dentry * dentry, struct dentry * target)
static void __d_move(struct dentry *dentry, struct dentry *target,
bool exchange)
{
if (!dentry->d_inode)
printk(KERN_WARNING "VFS: moving negative dcache entry\n");
......@@ -2573,8 +2577,15 @@ static void __d_move(struct dentry * dentry, struct dentry * target)
__d_drop(dentry);
__d_rehash(dentry, d_hash(target->d_parent, target->d_name.hash));
/* Unhash the target: dput() will then get rid of it */
/*
* Unhash the target (d_delete() is not usable here). If exchanging
* the two dentries, then rehash onto the other's hash queue.
*/
__d_drop(target);
if (exchange) {
__d_rehash(target,
d_hash(dentry->d_parent, dentry->d_name.hash));
}
list_del(&dentry->d_u.d_child);
list_del(&target->d_u.d_child);
......@@ -2601,6 +2612,8 @@ static void __d_move(struct dentry * dentry, struct dentry * target)
write_seqcount_end(&dentry->d_seq);
dentry_unlock_parents_for_move(dentry, target);
if (exchange)
fsnotify_d_move(target);
spin_unlock(&target->d_lock);
fsnotify_d_move(dentry);
spin_unlock(&dentry->d_lock);
......@@ -2618,11 +2631,30 @@ static void __d_move(struct dentry * dentry, struct dentry * target)
void d_move(struct dentry *dentry, struct dentry *target)
{
write_seqlock(&rename_lock);
__d_move(dentry, target);
__d_move(dentry, target, false);
write_sequnlock(&rename_lock);
}
EXPORT_SYMBOL(d_move);
/*
* d_exchange - exchange two dentries
* @dentry1: first dentry
* @dentry2: second dentry
*/
void d_exchange(struct dentry *dentry1, struct dentry *dentry2)
{
write_seqlock(&rename_lock);
WARN_ON(!dentry1->d_inode);
WARN_ON(!dentry2->d_inode);
WARN_ON(IS_ROOT(dentry1));
WARN_ON(IS_ROOT(dentry2));
__d_move(dentry1, dentry2, true);
write_sequnlock(&rename_lock);
}
/**
* d_ancestor - search for an ancestor
* @p1: ancestor dentry
......@@ -2670,7 +2702,7 @@ static struct dentry *__d_unalias(struct inode *inode,
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
if (likely(!d_mountpoint(alias))) {
__d_move(alias, dentry);
__d_move(alias, dentry, false);
ret = alias;
}
out_err:
......
......@@ -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)
......
This diff is collapsed.
......@@ -944,24 +944,22 @@ EXPORT_SYMBOL(unlock_new_inode);
/**
* lock_two_nondirectories - take two i_mutexes on non-directory objects
*
* Lock any non-NULL argument that is not a directory.
* Zero, one or two objects may be locked by this function.
*
* @inode1: first inode to lock
* @inode2: second inode to lock
*/
void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
{
WARN_ON_ONCE(S_ISDIR(inode1->i_mode));
if (inode1 == inode2 || !inode2) {
mutex_lock(&inode1->i_mutex);
return;
}
WARN_ON_ONCE(S_ISDIR(inode2->i_mode));
if (inode1 < inode2) {
if (inode1 > inode2)
swap(inode1, inode2);
if (inode1 && !S_ISDIR(inode1->i_mode))
mutex_lock(&inode1->i_mutex);
if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1)
mutex_lock_nested(&inode2->i_mutex, I_MUTEX_NONDIR2);
} else {
mutex_lock(&inode2->i_mutex);
mutex_lock_nested(&inode1->i_mutex, I_MUTEX_NONDIR2);
}
}
EXPORT_SYMBOL(lock_two_nondirectories);
......@@ -972,8 +970,9 @@ EXPORT_SYMBOL(lock_two_nondirectories);
*/
void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2)
{
if (inode1 && !S_ISDIR(inode1->i_mode))
mutex_unlock(&inode1->i_mutex);
if (inode2 && inode2 != inode1)
if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1)
mutex_unlock(&inode2->i_mutex);
}
EXPORT_SYMBOL(unlock_two_nondirectories);
......
This diff is collapsed.
......@@ -1694,7 +1694,7 @@ 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)
......
......@@ -308,6 +308,7 @@ extern void dentry_update_name_case(struct dentry *, struct qstr *);
/* used for rename() and baskets */
extern void d_move(struct dentry *, struct dentry *);
extern void d_exchange(struct dentry *, struct dentry *);
extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
/* appendix may either be NULL or be used for transname suffixes */
......@@ -429,7 +430,7 @@ static inline unsigned __d_entry_type(const struct dentry *dentry)
return dentry->d_flags & DCACHE_ENTRY_TYPE;
}
static inline bool d_is_directory(const struct dentry *dentry)
static inline bool d_can_lookup(const struct dentry *dentry)
{
return __d_entry_type(dentry) == DCACHE_DIRECTORY_TYPE;
}
......@@ -439,6 +440,11 @@ static inline bool d_is_autodir(const struct dentry *dentry)
return __d_entry_type(dentry) == DCACHE_AUTODIR_TYPE;
}
static inline bool d_is_dir(const struct dentry *dentry)
{
return d_can_lookup(dentry) || d_is_autodir(dentry);
}
static inline bool d_is_symlink(const struct dentry *dentry)
{
return __d_entry_type(dentry) == DCACHE_SYMLINK_TYPE;
......
......@@ -1461,7 +1461,7 @@ 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.
......@@ -1572,6 +1572,8 @@ 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);
......
......@@ -1793,7 +1793,8 @@ int security_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
int security_inode_rmdir(struct inode *dir, struct dentry *dentry);
int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev);
int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry);
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags);
int security_inode_readlink(struct dentry *dentry);
int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd);
int security_inode_permission(struct inode *inode, int mask);
......@@ -2161,7 +2162,8 @@ static inline int security_inode_mknod(struct inode *dir,
static inline int security_inode_rename(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry)
struct dentry *new_dentry,
unsigned int flags)
{
return 0;
}
......@@ -2955,7 +2957,8 @@ int security_path_symlink(struct path *dir, struct dentry *dentry,
int security_path_link(struct dentry *old_dentry, struct path *new_dir,
struct dentry *new_dentry);
int security_path_rename(struct path *old_dir, struct dentry *old_dentry,
struct path *new_dir, struct dentry *new_dentry);
struct path *new_dir, struct dentry *new_dentry,
unsigned int flags);
int security_path_chmod(struct path *path, umode_t mode);
int security_path_chown(struct path *path, kuid_t uid, kgid_t gid);
int security_path_chroot(struct path *path);
......@@ -3003,7 +3006,8 @@ static inline int security_path_link(struct dentry *old_dentry,
static inline int security_path_rename(struct path *old_dir,
struct dentry *old_dentry,
struct path *new_dir,
struct dentry *new_dentry)
struct dentry *new_dentry,
unsigned int flags)
{
return 0;
}
......
......@@ -35,6 +35,9 @@
#define SEEK_HOLE 4 /* seek to the next hole */
#define SEEK_MAX SEEK_HOLE
#define RENAME_NOREPLACE (1 << 0) /* Don't overwrite target */
#define RENAME_EXCHANGE (1 << 1) /* Exchange source and dest */
struct fstrim_range {
__u64 start;
__u64 len;
......
......@@ -433,11 +433,20 @@ int security_path_link(struct dentry *old_dentry, struct path *new_dir,
}
int security_path_rename(struct path *old_dir, struct dentry *old_dentry,
struct path *new_dir, struct dentry *new_dentry)
struct path *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (unlikely(IS_PRIVATE(old_dentry->d_inode) ||
(new_dentry->d_inode && IS_PRIVATE(new_dentry->d_inode))))
return 0;
if (flags & RENAME_EXCHANGE) {
int err = security_ops->path_rename(new_dir, new_dentry,
old_dir, old_dentry);
if (err)
return err;
}
return security_ops->path_rename(old_dir, old_dentry, new_dir,
new_dentry);
}
......@@ -524,11 +533,20 @@ int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
}
int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (unlikely(IS_PRIVATE(old_dentry->d_inode) ||
(new_dentry->d_inode && IS_PRIVATE(new_dentry->d_inode))))
return 0;
if (flags & RENAME_EXCHANGE) {
int err = security_ops->inode_rename(new_dir, new_dentry,
old_dir, old_dentry);
if (err)
return err;
}
return security_ops->inode_rename(old_dir, old_dentry,
new_dir, new_dentry);
}
......
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