[PATCH] fdtable: Provide free_fdtable() wrapper

Christoph Hellwig has expressed concerns that the recent fdtable changes expose the details of the RCU methodology used to release no-longer-used fdtable structures to the rest of the kernel. The trivial patch below addresses these concerns by introducing the appropriate free_fdtable() calls, which simply wrap the release RCU usage. Since free_fdtable() is a one-liner, it makes sense to promote it to an inline helper. Signed-off-by: Vadim Lobanov <[email protected]> Cc: Christoph Hellwig <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
niw · Dec 22, 2006 · 01b2d93 · 01b2d93
1 parent 31fccf7
commit 01b2d93
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Showing 3 changed files with 7 additions and 2 deletions.
diff --git a/fs/file.c b/fs/file.c
@@ -206,7 +206,7 @@ static int expand_fdtable(struct files_struct *files, int nr)
 		copy_fdtable(new_fdt, cur_fdt);
 		rcu_assign_pointer(files->fdt, new_fdt);
 		if (cur_fdt->max_fds > NR_OPEN_DEFAULT)
-			call_rcu(&cur_fdt->rcu, free_fdtable_rcu);
+			free_fdtable(cur_fdt);
 	} else {
 		/* Somebody else expanded, so undo our attempt */
 		free_fdarr(new_fdt);

diff --git a/include/linux/file.h b/include/linux/file.h
@@ -80,6 +80,11 @@ extern int expand_files(struct files_struct *, int nr);
 extern void free_fdtable_rcu(struct rcu_head *rcu);
 extern void __init files_defer_init(void);
 
+static inline void free_fdtable(struct fdtable *fdt)
+{
+	call_rcu(&fdt->rcu, free_fdtable_rcu);
+}
+
 static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
 {
 	struct file * file = NULL;

diff --git a/kernel/exit.c b/kernel/exit.c
@@ -468,7 +468,7 @@ void fastcall put_files_struct(struct files_struct *files)
 		fdt = files_fdtable(files);
 		if (fdt != &files->fdtab)
 			kmem_cache_free(files_cachep, files);
-		call_rcu(&fdt->rcu, free_fdtable_rcu);
+		free_fdtable(fdt);
 	}
 }