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-rw-r--r--fs/namei.c75
1 files changed, 48 insertions, 27 deletions
diff --git a/fs/namei.c b/fs/namei.c
index c981dec3c..9342fa6a3 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -289,7 +289,7 @@ EXPORT_SYMBOL(putname);
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
static int check_acl(struct mnt_idmap *idmap,
struct inode *inode, int mask)
@@ -334,7 +334,7 @@ static int check_acl(struct mnt_idmap *idmap,
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
static int acl_permission_check(struct mnt_idmap *idmap,
struct inode *inode, int mask)
@@ -395,7 +395,7 @@ static int acl_permission_check(struct mnt_idmap *idmap,
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int generic_permission(struct mnt_idmap *idmap, struct inode *inode,
int mask)
@@ -1071,7 +1071,6 @@ static struct ctl_table namei_sysctls[] = {
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_TWO,
},
- { }
};
static int __init init_fs_namei_sysctls(void)
@@ -1718,7 +1717,11 @@ static inline int may_lookup(struct mnt_idmap *idmap,
{
if (nd->flags & LOOKUP_RCU) {
int err = inode_permission(idmap, nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
- if (err != -ECHILD || !try_to_unlazy(nd))
+ if (!err) // success, keep going
+ return 0;
+ if (!try_to_unlazy(nd))
+ return -ECHILD; // redo it all non-lazy
+ if (err != -ECHILD) // hard error
return err;
}
return inode_permission(idmap, nd->inode, MAY_EXEC);
@@ -2467,7 +2470,7 @@ static int handle_lookup_down(struct nameidata *nd)
return PTR_ERR(step_into(nd, WALK_NOFOLLOW, nd->path.dentry));
}
-/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
+/* Returns 0 and nd will be valid on success; Returns error, otherwise. */
static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path)
{
const char *s = path_init(nd, flags);
@@ -2522,7 +2525,7 @@ int filename_lookup(int dfd, struct filename *name, unsigned flags,
return retval;
}
-/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
+/* Returns 0 and nd will be valid on success; Returns error, otherwise. */
static int path_parentat(struct nameidata *nd, unsigned flags,
struct path *parent)
{
@@ -3024,21 +3027,37 @@ static inline int may_create(struct mnt_idmap *idmap,
return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
}
+// p1 != p2, both are on the same filesystem, ->s_vfs_rename_mutex is held
static struct dentry *lock_two_directories(struct dentry *p1, struct dentry *p2)
{
- struct dentry *p;
+ struct dentry *p = p1, *q = p2, *r;
- p = d_ancestor(p2, p1);
- if (p) {
+ while ((r = p->d_parent) != p2 && r != p)
+ p = r;
+ if (r == p2) {
+ // p is a child of p2 and an ancestor of p1 or p1 itself
inode_lock_nested(p2->d_inode, I_MUTEX_PARENT);
inode_lock_nested(p1->d_inode, I_MUTEX_PARENT2);
return p;
}
-
- p = d_ancestor(p1, p2);
- inode_lock_nested(p1->d_inode, I_MUTEX_PARENT);
- inode_lock_nested(p2->d_inode, I_MUTEX_PARENT2);
- return p;
+ // p is the root of connected component that contains p1
+ // p2 does not occur on the path from p to p1
+ while ((r = q->d_parent) != p1 && r != p && r != q)
+ q = r;
+ if (r == p1) {
+ // q is a child of p1 and an ancestor of p2 or p2 itself
+ inode_lock_nested(p1->d_inode, I_MUTEX_PARENT);
+ inode_lock_nested(p2->d_inode, I_MUTEX_PARENT2);
+ return q;
+ } else if (likely(r == p)) {
+ // both p2 and p1 are descendents of p
+ inode_lock_nested(p1->d_inode, I_MUTEX_PARENT);
+ inode_lock_nested(p2->d_inode, I_MUTEX_PARENT2);
+ return NULL;
+ } else { // no common ancestor at the time we'd been called
+ mutex_unlock(&p1->d_sb->s_vfs_rename_mutex);
+ return ERR_PTR(-EXDEV);
+ }
}
/*
@@ -3162,7 +3181,7 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int vfs_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool want_excl)
@@ -3650,7 +3669,7 @@ static int do_open(struct nameidata *nd,
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
static int vfs_tmpfile(struct mnt_idmap *idmap,
const struct path *parentpath,
@@ -3789,10 +3808,7 @@ static struct file *path_openat(struct nameidata *nd,
WARN_ON(1);
error = -EINVAL;
}
- if (unlikely(file->f_mode & FMODE_OPENED))
- fput(file);
- else
- release_empty_file(file);
+ fput(file);
if (error == -EOPENSTALE) {
if (flags & LOOKUP_RCU)
error = -ECHILD;
@@ -3958,7 +3974,7 @@ EXPORT_SYMBOL(user_path_create);
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t dev)
@@ -4084,7 +4100,7 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
@@ -4165,7 +4181,7 @@ SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int vfs_rmdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry)
@@ -4294,7 +4310,7 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int vfs_unlink(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, struct inode **delegated_inode)
@@ -4447,7 +4463,7 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname)
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, const char *oldname)
@@ -4539,7 +4555,7 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn
* the vfsmount must be passed through @idmap. This function will then take
* care to map the inode according to @idmap before checking permissions.
* On non-idmapped mounts or if permission checking is to be performed on the
- * raw inode simply passs @nop_mnt_idmap.
+ * raw inode simply pass @nop_mnt_idmap.
*/
int vfs_link(struct dentry *old_dentry, struct mnt_idmap *idmap,
struct inode *dir, struct dentry *new_dentry,
@@ -4957,6 +4973,10 @@ retry:
retry_deleg:
trap = lock_rename(new_path.dentry, old_path.dentry);
+ if (IS_ERR(trap)) {
+ error = PTR_ERR(trap);
+ goto exit_lock_rename;
+ }
old_dentry = lookup_one_qstr_excl(&old_last, old_path.dentry,
lookup_flags);
@@ -5024,6 +5044,7 @@ exit4:
dput(old_dentry);
exit3:
unlock_rename(new_path.dentry, old_path.dentry);
+exit_lock_rename:
if (delegated_inode) {
error = break_deleg_wait(&delegated_inode);
if (!error)
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-16 03:13:33 +0000