X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Ffile_table.c;h=334ce39881f8fea36897196a262f4164cccde1f8;hb=4eb3991c5def39bcf553c14ebe2618fcb47b627f;hp=f45a4493f9e71b5afe52640f453a33bce0603c70;hpb=516e0cc5646f377ab80fcc2ee639892eccb99853;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/file_table.c b/fs/file_table.c
index f45a449..334ce39 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/security.h>
+#include <linux/ima.h>
 #include <linux/eventpoll.h>
 #include <linux/rcupdate.h>
 #include <linux/mount.h>
@@ -32,11 +33,16 @@ struct files_stat_struct files_stat = {
 /* public. Not pretty! */
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(files_lock);
 
+/* SLAB cache for file structures */
+static struct kmem_cache *filp_cachep __read_mostly;
+
 static struct percpu_counter nr_files __cacheline_aligned_in_smp;
 
 static inline void file_free_rcu(struct rcu_head *head)
 {
-	struct file *f =  container_of(head, struct file, f_u.fu_rcuhead);
+	struct file *f = container_of(head, struct file, f_u.fu_rcuhead);
+
+	put_cred(f->f_cred);
 	kmem_cache_free(filp_cachep, f);
 }
 
@@ -94,7 +100,7 @@ int proc_nr_files(ctl_table *table, int write, struct file *filp,
  */
 struct file *get_empty_filp(void)
 {
-	struct task_struct *tsk;
+	const struct cred *cred = current_cred();
 	static int old_max;
 	struct file * f;
 
@@ -118,12 +124,11 @@ struct file *get_empty_filp(void)
 	if (security_file_alloc(f))
 		goto fail_sec;
 
-	tsk = current;
 	INIT_LIST_HEAD(&f->f_u.fu_list);
 	atomic_long_set(&f->f_count, 1);
 	rwlock_init(&f->f_owner.lock);
-	f->f_uid = tsk->fsuid;
-	f->f_gid = tsk->fsgid;
+	f->f_cred = get_cred(cred);
+	spin_lock_init(&f->f_lock);
 	eventpoll_init_file(f);
 	/* f->f_version: 0 */
 	return f;
@@ -161,10 +166,9 @@ EXPORT_SYMBOL(get_empty_filp);
  * code should be moved into this function.
  */
 struct file *alloc_file(struct vfsmount *mnt, struct dentry *dentry,
-		mode_t mode, const struct file_operations *fop)
+		fmode_t mode, const struct file_operations *fop)
 {
 	struct file *file;
-	struct path;
 
 	file = get_empty_filp();
 	if (!file)
@@ -193,7 +197,7 @@ EXPORT_SYMBOL(alloc_file);
  * of this should be moving to alloc_file().
  */
 int init_file(struct file *file, struct vfsmount *mnt, struct dentry *dentry,
-	   mode_t mode, const struct file_operations *fop)
+	   fmode_t mode, const struct file_operations *fop)
 {
 	int error = 0;
 	file->f_path.dentry = dentry;
@@ -210,7 +214,7 @@ int init_file(struct file *file, struct vfsmount *mnt, struct dentry *dentry,
 	 */
 	if ((mode & FMODE_WRITE) && !special_file(dentry->d_inode->i_mode)) {
 		file_take_write(file);
-		error = mnt_want_write(mnt);
+		error = mnt_clone_write(mnt);
 		WARN_ON(error);
 	}
 	return error;
@@ -269,9 +273,14 @@ void __fput(struct file *file)
 	eventpoll_release(file);
 	locks_remove_flock(file);
 
+	if (unlikely(file->f_flags & FASYNC)) {
+		if (file->f_op && file->f_op->fasync)
+			file->f_op->fasync(-1, file, 0);
+	}
 	if (file->f_op && file->f_op->release)
 		file->f_op->release(inode, file);
 	security_file_free(file);
+	ima_file_free(file);
 	if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL))
 		cdev_put(inode->i_cdev);
 	fops_put(file->f_op);
@@ -390,10 +399,53 @@ too_bad:
 	return 0;
 }
 
+/**
+ *	mark_files_ro - mark all files read-only
+ *	@sb: superblock in question
+ *
+ *	All files are marked read-only.  We don't care about pending
+ *	delete files so this should be used in 'force' mode only.
+ */
+void mark_files_ro(struct super_block *sb)
+{
+	struct file *f;
+
+retry:
+	file_list_lock();
+	list_for_each_entry(f, &sb->s_files, f_u.fu_list) {
+		struct vfsmount *mnt;
+		if (!S_ISREG(f->f_path.dentry->d_inode->i_mode))
+		       continue;
+		if (!file_count(f))
+			continue;
+		if (!(f->f_mode & FMODE_WRITE))
+			continue;
+		f->f_mode &= ~FMODE_WRITE;
+		if (file_check_writeable(f) != 0)
+			continue;
+		file_release_write(f);
+		mnt = mntget(f->f_path.mnt);
+		file_list_unlock();
+		/*
+		 * This can sleep, so we can't hold
+		 * the file_list_lock() spinlock.
+		 */
+		mnt_drop_write(mnt);
+		mntput(mnt);
+		goto retry;
+	}
+	file_list_unlock();
+}
+
 void __init files_init(unsigned long mempages)
 { 
 	int n; 
-	/* One file with associated inode and dcache is very roughly 1K. 
+
+	filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
+			SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
+
+	/*
+	 * One file with associated inode and dcache is very roughly 1K.
 	 * Per default don't use more than 10% of our memory for files. 
 	 */