X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Ffile_table.c;h=768b581675433ed0e02eb0a9bcf35288de7adca5;hb=9f5974c8734d83d4ab7096ed98136a82f41210d6;hp=43e9e1737de2cb365c954afeddfb64ae0433779b;hpb=529980c8b0b04e8a3f6606cdc156f1f81a5d68cd;p=linux-2.6

diff --git a/fs/file_table.c b/fs/file_table.c
index 43e9e1737d..768b581675 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -14,7 +14,9 @@
 #include <linux/fs.h>
 #include <linux/security.h>
 #include <linux/eventpoll.h>
+#include <linux/rcupdate.h>
 #include <linux/mount.h>
+#include <linux/capability.h>
 #include <linux/cdev.h>
 #include <linux/fsnotify.h>
 
@@ -34,7 +36,7 @@ static DEFINE_SPINLOCK(filp_count_lock);
  * context and must be fully threaded - use a local spinlock
  * to protect files_stat.nr_files
  */
-void filp_ctor(void * objp, struct kmem_cache_s *cachep, unsigned long cflags)
+void filp_ctor(void *objp, struct kmem_cache *cachep, unsigned long cflags)
 {
 	if ((cflags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 	    SLAB_CTOR_CONSTRUCTOR) {
@@ -45,7 +47,7 @@ void filp_ctor(void * objp, struct kmem_cache_s *cachep, unsigned long cflags)
 	}
 }
 
-void filp_dtor(void * objp, struct kmem_cache_s *cachep, unsigned long dflags)
+void filp_dtor(void *objp, struct kmem_cache *cachep, unsigned long dflags)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&filp_count_lock, flags);
@@ -53,11 +55,17 @@ void filp_dtor(void * objp, struct kmem_cache_s *cachep, unsigned long dflags)
 	spin_unlock_irqrestore(&filp_count_lock, flags);
 }
 
-static inline void file_free(struct file *f)
+static inline void file_free_rcu(struct rcu_head *head)
 {
+	struct file *f =  container_of(head, struct file, f_u.fu_rcuhead);
 	kmem_cache_free(filp_cachep, f);
 }
 
+static inline void file_free(struct file *f)
+{
+	call_rcu(&f->f_u.fu_rcuhead, file_free_rcu);
+}
+
 /* Find an unused file structure and return a pointer to it.
  * Returns NULL, if there are no more free file structures or
  * we run out of memory.
@@ -88,7 +96,7 @@ struct file *get_empty_filp(void)
 	f->f_gid = current->fsgid;
 	rwlock_init(&f->f_owner.lock);
 	/* f->f_version: 0 */
-	INIT_LIST_HEAD(&f->f_list);
+	INIT_LIST_HEAD(&f->f_u.fu_list);
 	return f;
 
 over:
@@ -156,11 +164,17 @@ struct file fastcall *fget(unsigned int fd)
 	struct file *file;
 	struct files_struct *files = current->files;
 
-	spin_lock(&files->file_lock);
+	rcu_read_lock();
 	file = fcheck_files(files, fd);
-	if (file)
-		get_file(file);
-	spin_unlock(&files->file_lock);
+	if (file) {
+		if (!atomic_inc_not_zero(&file->f_count)) {
+			/* File object ref couldn't be taken */
+			rcu_read_unlock();
+			return NULL;
+		}
+	}
+	rcu_read_unlock();
+
 	return file;
 }
 
@@ -182,14 +196,18 @@ struct file fastcall *fget_light(unsigned int fd, int *fput_needed)
 	if (likely((atomic_read(&files->count) == 1))) {
 		file = fcheck_files(files, fd);
 	} else {
-		spin_lock(&files->file_lock);
+		rcu_read_lock();
 		file = fcheck_files(files, fd);
 		if (file) {
-			get_file(file);
-			*fput_needed = 1;
+			if (atomic_inc_not_zero(&file->f_count))
+				*fput_needed = 1;
+			else
+				/* Didn't get the reference, someone's freed */
+				file = NULL;
 		}
-		spin_unlock(&files->file_lock);
+		rcu_read_unlock();
 	}
+
 	return file;
 }
 
@@ -208,15 +226,15 @@ void file_move(struct file *file, struct list_head *list)
 	if (!list)
 		return;
 	file_list_lock();
-	list_move(&file->f_list, list);
+	list_move(&file->f_u.fu_list, list);
 	file_list_unlock();
 }
 
 void file_kill(struct file *file)
 {
-	if (!list_empty(&file->f_list)) {
+	if (!list_empty(&file->f_u.fu_list)) {
 		file_list_lock();
-		list_del_init(&file->f_list);
+		list_del_init(&file->f_u.fu_list);
 		file_list_unlock();
 	}
 }
@@ -228,7 +246,7 @@ int fs_may_remount_ro(struct super_block *sb)
 	/* Check that no files are currently opened for writing. */
 	file_list_lock();
 	list_for_each(p, &sb->s_files) {
-		struct file *file = list_entry(p, struct file, f_list);
+		struct file *file = list_entry(p, struct file, f_u.fu_list);
 		struct inode *inode = file->f_dentry->d_inode;
 
 		/* File with pending delete? */
@@ -257,4 +275,5 @@ void __init files_init(unsigned long mempages)
 	files_stat.max_files = n; 
 	if (files_stat.max_files < NR_FILE)
 		files_stat.max_files = NR_FILE;
+	files_defer_init();
 }