aboutsummaryrefslogtreecommitdiffstats
path: root/fs/namei.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c315
1 files changed, 171 insertions, 144 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 4b491b431990..c1178880f23c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1796,7 +1796,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
if (err)
return err;
}
- if (!d_is_directory(nd->path.dentry)) {
+ if (!d_can_lookup(nd->path.dentry)) {
err = -ENOTDIR;
break;
}
@@ -1817,7 +1817,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
struct dentry *root = nd->root.dentry;
struct inode *inode = root->d_inode;
if (*name) {
- if (!d_is_directory(root))
+ if (!d_can_lookup(root))
return -ENOTDIR;
retval = inode_permission(inode, MAY_EXEC);
if (retval)
@@ -1873,7 +1873,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
dentry = f.file->f_path.dentry;
if (*name) {
- if (!d_is_directory(dentry)) {
+ if (!d_can_lookup(dentry)) {
fdput(f);
return -ENOTDIR;
}
@@ -1955,7 +1955,7 @@ static int path_lookupat(int dfd, const char *name,
err = complete_walk(nd);
if (!err && nd->flags & LOOKUP_DIRECTORY) {
- if (!d_is_directory(nd->path.dentry)) {
+ if (!d_can_lookup(nd->path.dentry)) {
path_put(&nd->path);
err = -ENOTDIR;
}
@@ -2414,11 +2414,11 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir)
IS_IMMUTABLE(inode) || IS_SWAPFILE(inode))
return -EPERM;
if (isdir) {
- if (!d_is_directory(victim) && !d_is_autodir(victim))
+ if (!d_is_dir(victim))
return -ENOTDIR;
if (IS_ROOT(victim))
return -EBUSY;
- } else if (d_is_directory(victim) || d_is_autodir(victim))
+ } else if (d_is_dir(victim))
return -EISDIR;
if (IS_DEADDIR(dir))
return -ENOENT;
@@ -3016,11 +3016,10 @@ finish_open:
}
audit_inode(name, nd->path.dentry, 0);
error = -EISDIR;
- if ((open_flag & O_CREAT) &&
- (d_is_directory(nd->path.dentry) || d_is_autodir(nd->path.dentry)))
+ if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
goto out;
error = -ENOTDIR;
- if ((nd->flags & LOOKUP_DIRECTORY) && !d_is_directory(nd->path.dentry))
+ if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.dentry))
goto out;
if (!S_ISREG(nd->inode->i_mode))
will_truncate = false;
@@ -3744,7 +3743,7 @@ exit1:
slashes:
if (d_is_negative(dentry))
error = -ENOENT;
- else if (d_is_directory(dentry) || d_is_autodir(dentry))
+ else if (d_is_dir(dentry))
error = -EISDIR;
else
error = -ENOTDIR;
@@ -3974,7 +3973,28 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
}
-/*
+/**
+ * vfs_rename - rename a filesystem object
+ * @old_dir: parent of source
+ * @old_dentry: source
+ * @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()).
+ *
+ * If vfs_rename discovers a delegation in need of breaking at either
+ * the source or destination, it will return -EWOULDBLOCK and return a
+ * reference to the inode in delegated_inode. The caller should then
+ * break the delegation and retry. Because breaking a delegation may
+ * take a long time, the caller should drop all locks before doing
+ * so.
+ *
+ * Alternatively, a caller may pass NULL for delegated_inode. This may
+ * be appropriate for callers that expect the underlying filesystem not
+ * to be NFS exported.
+ *
* The worst of all namespace operations - renaming directory. "Perverted"
* doesn't even start to describe it. Somebody in UCB had a heck of a trip...
* Problems:
@@ -4002,163 +4022,139 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
* ->i_mutex on parents, which works but leads to some truly excessive
* locking].
*/
-static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry)
+int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ struct inode **delegated_inode, unsigned int flags)
{
- int error = 0;
+ int error;
+ bool is_dir = d_is_dir(old_dentry);
+ const unsigned char *old_name;
+ struct inode *source = old_dentry->d_inode;
struct inode *target = new_dentry->d_inode;
+ bool new_is_dir = false;
unsigned max_links = new_dir->i_sb->s_max_links;
+ if (source == target)
+ return 0;
+
+ error = may_delete(old_dir, old_dentry, is_dir);
+ if (error)
+ return error;
+
+ if (!target) {
+ error = may_create(new_dir, new_dentry);
+ } else {
+ new_is_dir = d_is_dir(new_dentry);
+
+ if (!(flags & RENAME_EXCHANGE))
+ error = may_delete(new_dir, new_dentry, is_dir);
+ else
+ error = may_delete(new_dir, new_dentry, new_is_dir);
+ }
+ if (error)
+ return error;
+
+ 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 '..'.
*/
if (new_dir != old_dir) {
- error = inode_permission(old_dentry->d_inode, MAY_WRITE);
- if (error)
- return error;
+ if (is_dir) {
+ error = inode_permission(source, MAY_WRITE);
+ if (error)
+ return error;
+ }
+ if ((flags & RENAME_EXCHANGE) && new_is_dir) {
+ error = inode_permission(target, MAY_WRITE);
+ if (error)
+ return error;
+ }
}
- error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
+ error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry,
+ flags);
if (error)
return error;
+ old_name = fsnotify_oldname_init(old_dentry->d_name.name);
dget(new_dentry);
- if (target)
+ if (!is_dir || (flags & RENAME_EXCHANGE))
+ lock_two_nondirectories(source, target);
+ else if (target)
mutex_lock(&target->i_mutex);
error = -EBUSY;
if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
goto out;
- error = -EMLINK;
- if (max_links && !target && new_dir != old_dir &&
- new_dir->i_nlink >= max_links)
- goto out;
-
- if (target)
+ if (max_links && new_dir != old_dir) {
+ error = -EMLINK;
+ if (is_dir && !new_is_dir && new_dir->i_nlink >= max_links)
+ goto out;
+ if ((flags & RENAME_EXCHANGE) && !is_dir && new_is_dir &&
+ old_dir->i_nlink >= max_links)
+ goto out;
+ }
+ if (is_dir && !(flags & RENAME_EXCHANGE) && target)
shrink_dcache_parent(new_dentry);
- error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
- if (error)
- goto out;
-
- if (target) {
- target->i_flags |= S_DEAD;
- dont_mount(new_dentry);
+ if (!is_dir) {
+ error = try_break_deleg(source, delegated_inode);
+ if (error)
+ goto out;
}
-out:
- if (target)
- mutex_unlock(&target->i_mutex);
- dput(new_dentry);
- if (!error)
- if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
- d_move(old_dentry,new_dentry);
- return error;
-}
-
-static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry,
- struct inode **delegated_inode)
-{
- struct inode *target = new_dentry->d_inode;
- struct inode *source = old_dentry->d_inode;
- int error;
-
- error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
- if (error)
- return error;
-
- dget(new_dentry);
- lock_two_nondirectories(source, target);
-
- error = -EBUSY;
- if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
- goto out;
-
- error = try_break_deleg(source, delegated_inode);
- if (error)
- goto out;
- if (target) {
+ if (target && !new_is_dir) {
error = try_break_deleg(target, delegated_inode);
if (error)
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;
- if (target)
+ if (!(flags & RENAME_EXCHANGE) && target) {
+ if (is_dir)
+ target->i_flags |= S_DEAD;
dont_mount(new_dentry);
- if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
- d_move(old_dentry, new_dentry);
+ }
+ if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) {
+ if (!(flags & RENAME_EXCHANGE))
+ d_move(old_dentry, new_dentry);
+ else
+ d_exchange(old_dentry, new_dentry);
+ }
out:
- unlock_two_nondirectories(source, target);
+ if (!is_dir || (flags & RENAME_EXCHANGE))
+ unlock_two_nondirectories(source, target);
+ else if (target)
+ mutex_unlock(&target->i_mutex);
dput(new_dentry);
- return error;
-}
-
-/**
- * vfs_rename - rename a filesystem object
- * @old_dir: parent of source
- * @old_dentry: source
- * @new_dir: parent of destination
- * @new_dentry: destination
- * @delegated_inode: returns an inode needing a delegation break
- *
- * The caller must hold multiple mutexes--see lock_rename()).
- *
- * If vfs_rename discovers a delegation in need of breaking at either
- * the source or destination, it will return -EWOULDBLOCK and return a
- * reference to the inode in delegated_inode. The caller should then
- * break the delegation and retry. Because breaking a delegation may
- * take a long time, the caller should drop all locks before doing
- * so.
- *
- * Alternatively, a caller may pass NULL for delegated_inode. This may
- * be appropriate for callers that expect the underlying filesystem not
- * to be NFS exported.
- */
-int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry,
- struct inode **delegated_inode)
-{
- int error;
- int is_dir = d_is_directory(old_dentry) || d_is_autodir(old_dentry);
- const unsigned char *old_name;
-
- if (old_dentry->d_inode == new_dentry->d_inode)
- return 0;
-
- error = may_delete(old_dir, old_dentry, is_dir);
- if (error)
- return error;
-
- if (!new_dentry->d_inode)
- error = may_create(new_dir, new_dentry);
- else
- error = may_delete(new_dir, new_dentry, is_dir);
- if (error)
- return error;
-
- if (!old_dir->i_op->rename)
- return -EPERM;
-
- old_name = fsnotify_oldname_init(old_dentry->d_name.name);
-
- if (is_dir)
- error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
- else
- error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode);
- if (!error)
+ if (!error) {
fsnotify_move(old_dir, new_dir, old_name, is_dir,
- new_dentry->d_inode, old_dentry);
+ !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry);
+ if (flags & RENAME_EXCHANGE) {
+ fsnotify_move(new_dir, old_dir, old_dentry->d_name.name,
+ new_is_dir, NULL, new_dentry);
+ }
+ }
fsnotify_oldname_free(old_name);
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;
@@ -4170,6 +4166,13 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
unsigned int lookup_flags = 0;
bool should_retry = false;
int error;
+
+ if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+ return -EINVAL;
+
+ if ((flags & RENAME_NOREPLACE) && (flags & RENAME_EXCHANGE))
+ return -EINVAL;
+
retry:
from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
if (IS_ERR(from)) {
@@ -4193,6 +4196,8 @@ retry:
goto exit2;
new_dir = newnd.path.dentry;
+ if (flags & RENAME_NOREPLACE)
+ error = -EEXIST;
if (newnd.last_type != LAST_NORM)
goto exit2;
@@ -4202,7 +4207,8 @@ retry:
oldnd.flags &= ~LOOKUP_PARENT;
newnd.flags &= ~LOOKUP_PARENT;
- newnd.flags |= LOOKUP_RENAME_TARGET;
+ if (!(flags & RENAME_EXCHANGE))
+ newnd.flags |= LOOKUP_RENAME_TARGET;
retry_deleg:
trap = lock_rename(new_dir, old_dir);
@@ -4215,34 +4221,49 @@ retry_deleg:
error = -ENOENT;
if (d_is_negative(old_dentry))
goto exit4;
+ new_dentry = lookup_hash(&newnd);
+ error = PTR_ERR(new_dentry);
+ if (IS_ERR(new_dentry))
+ goto exit4;
+ error = -EEXIST;
+ if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry))
+ goto exit5;
+ if (flags & RENAME_EXCHANGE) {
+ error = -ENOENT;
+ if (d_is_negative(new_dentry))
+ goto exit5;
+
+ if (!d_is_dir(new_dentry)) {
+ error = -ENOTDIR;
+ if (newnd.last.name[newnd.last.len])
+ goto exit5;
+ }
+ }
/* unless the source is a directory trailing slashes give -ENOTDIR */
- if (!d_is_directory(old_dentry) && !d_is_autodir(old_dentry)) {
+ if (!d_is_dir(old_dentry)) {
error = -ENOTDIR;
if (oldnd.last.name[oldnd.last.len])
- goto exit4;
- if (newnd.last.name[newnd.last.len])
- goto exit4;
+ goto exit5;
+ if (!(flags & RENAME_EXCHANGE) && newnd.last.name[newnd.last.len])
+ goto exit5;
}
/* source should not be ancestor of target */
error = -EINVAL;
if (old_dentry == trap)
- goto exit4;
- new_dentry = lookup_hash(&newnd);
- error = PTR_ERR(new_dentry);
- if (IS_ERR(new_dentry))
- goto exit4;
+ goto exit5;
/* target should not be an ancestor of source */
- error = -ENOTEMPTY;
+ if (!(flags & RENAME_EXCHANGE))
+ error = -ENOTEMPTY;
if (new_dentry == trap)
goto exit5;
error = security_path_rename(&oldnd.path, old_dentry,
- &newnd.path, new_dentry);
+ &newnd.path, new_dentry, flags);
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:
@@ -4272,9 +4293,15 @@ 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)

Privacy Policy