Commit b0c013e2 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: add a new ioctl EXT4_IOC_CLEAR_ES_CACHE 



The new ioctl EXT4_IOC_CLEAR_ES_CACHE will force an inode's extent
status cache to be cleared out.  This is intended for use for
debugging.

Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 547b9ad6

fs/ext4/ext4.h

+2 −0
Original line number Diff line number Diff line
@@ -649,6 +649,8 @@ enum { 
#define EXT4_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY

#define EXT4_IOC_GET_ENCRYPTION_PWSALT	FS_IOC_GET_ENCRYPTION_PWSALT

#define EXT4_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY

/* ioctl codes 19--39 are reserved for fscrypt */

#define EXT4_IOC_CLEAR_ES_CACHE		_IO('f', 40)



#define EXT4_IOC_FSGETXATTR		FS_IOC_FSGETXATTR

#define EXT4_IOC_FSSETXATTR		FS_IOC_FSSETXATTR

fs/ext4/extents_status.c

+28 −0
Original line number Diff line number Diff line
@@ -1374,6 +1374,34 @@ static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan) 
	return nr_shrunk;

}



/*

 * Called to support EXT4_IOC_CLEAR_ES_CACHE.  We can only remove

 * discretionary entries from the extent status cache.  (Some entries

 * must be present for proper operations.)

 */

void ext4_clear_inode_es(struct inode *inode)

{

	struct ext4_inode_info *ei = EXT4_I(inode);

	struct extent_status *es;

	struct ext4_es_tree *tree;

	struct rb_node *node;



	write_lock(&ei->i_es_lock);

	tree = &EXT4_I(inode)->i_es_tree;

	tree->cache_es = NULL;

	node = rb_first(&tree->root);

	while (node) {

		es = rb_entry(node, struct extent_status, rb_node);

		node = rb_next(node);

		if (!ext4_es_is_delayed(es)) {

			rb_erase(&es->rb_node, &tree->root);

			ext4_es_free_extent(inode, es);

		}

	}

	ext4_clear_inode_state(inode, EXT4_STATE_EXT_PRECACHED);

	write_unlock(&ei->i_es_lock);

}



#ifdef ES_DEBUG__

static void ext4_print_pending_tree(struct inode *inode)

{

fs/ext4/extents_status.h

+1 −0
Original line number Diff line number Diff line
@@ -248,5 +248,6 @@ extern unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk, 
					ext4_lblk_t len);

extern void ext4_es_remove_blks(struct inode *inode, ext4_lblk_t lblk,

				ext4_lblk_t len);

extern void ext4_clear_inode_es(struct inode *inode);



#endif /* _EXT4_EXTENTS_STATUS_H */

fs/ext4/ioctl.c

+9 −0
Original line number Diff line number Diff line
@@ -1115,6 +1115,14 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
	case EXT4_IOC_GET_ENCRYPTION_POLICY:

		return fscrypt_ioctl_get_policy(filp, (void __user *)arg);



	case EXT4_IOC_CLEAR_ES_CACHE:

	{

		if (!inode_owner_or_capable(inode))

			return -EACCES;

		ext4_clear_inode_es(inode);

		return 0;

	}



	case EXT4_IOC_FSGETXATTR:

	{

		struct fsxattr fa;
@@ -1233,6 +1241,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	case EXT4_IOC_GET_ENCRYPTION_POLICY:

	case EXT4_IOC_SHUTDOWN:

	case FS_IOC_GETFSMAP:

	case EXT4_IOC_CLEAR_ES_CACHE:

		break;

	default:

		return -ENOIOCTLCMD;