[PATCH] unshare system call -v5: unshare filesystem info
If filesystem structure is being shared, allocate a new one and copy
information from the current, shared, structure.
Signed-off-by: Janak Desai <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Michael Kerrisk <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Paul Mackerras <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/kernel/fork.c b/kernel/fork.c
index 6eb9362..598e5c2 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1371,15 +1371,18 @@
}
/*
- * Unsharing of fs info for tasks created with CLONE_FS is not supported yet
+ * Unshare the filesystem structure if it is being shared
*/
static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
{
struct fs_struct *fs = current->fs;
if ((unshare_flags & CLONE_FS) &&
- (fs && atomic_read(&fs->count) > 1))
- return -EINVAL;
+ (fs && atomic_read(&fs->count) > 1)) {
+ *new_fsp = __copy_fs_struct(current->fs);
+ if (!*new_fsp)
+ return -ENOMEM;
+ }
return 0;
}
