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Commit b50d9aa3 authored by Paul Lawrence's avatar Paul Lawrence
Browse files

ANDROID: Incremental fs: Support xattrs 



To make selinux work, add xattr support. This is a bit clunky -
it seems like it would be better for the log and pending read
functionality to be ioctls rather than this mixture of real
and virtual files.

Bug: 133435829
Change-Id: I56579fabe2ae7efb88f0344553948dc9573299aa
Signed-off-by: default avatarPaul Lawrence <paullawrence@google.com>
parent 7a824723

fs/incfs/data_mgmt.c

+2 −0
Original line number Diff line number Diff line
@@ -68,6 +68,8 @@ void incfs_free_mount_info(struct mount_info *mi) 
	mutex_destroy(&mi->mi_pending_reads_mutex);

	put_cred(mi->mi_owner);

	kfree(mi->mi_log.rl_ring_buf);

	kfree(mi->log_xattr);

	kfree(mi->pending_read_xattr);

	kfree(mi);

}

fs/incfs/data_mgmt.h

+6 −0
Original line number Diff line number Diff line
@@ -105,6 +105,12 @@ struct mount_info { 


	/* Temporary buffer for read logger. */

	struct read_log mi_log;



	void *log_xattr;

	size_t log_xattr_size;



	void *pending_read_xattr;

	size_t pending_read_xattr_size;

};



struct data_file_block {

fs/incfs/vfs.c

+76 −2
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ static void evict_inode(struct inode *inode); 


static ssize_t incfs_getxattr(struct dentry *d, const char *name,

			void *value, size_t size);

static ssize_t incfs_setxattr(struct dentry *d, const char *name,

			const void *value, size_t size, int flags);

static ssize_t incfs_listxattr(struct dentry *d, char *list, size_t size);



static int show_options(struct seq_file *, struct dentry *);
@@ -166,9 +168,18 @@ static int incfs_handler_getxattr(const struct xattr_handler *xh, 
	return incfs_getxattr(d, name, buffer, size);

}



static int incfs_handler_setxattr(const struct xattr_handler *xh,

				  struct dentry *d, struct inode *inode,

				  const char *name, const void *buffer,

				  size_t size, int flags)

{

	return incfs_setxattr(d, name, buffer, size, flags);

}



static const struct xattr_handler incfs_xattr_handler = {

	.prefix = "",	/* AKA all attributes */

	.get = incfs_handler_getxattr,

	.set = incfs_handler_setxattr,

};



static const struct xattr_handler *incfs_xattr_ops[] = {
@@ -2045,11 +2056,74 @@ static ssize_t incfs_getxattr(struct dentry *d, const char *name, 
			void *value, size_t size)

{

	struct dentry_info *di = get_incfs_dentry(d);

	struct mount_info *mi = get_mount_info(d->d_sb);

	char *stored_value;

	size_t stored_size;



	if (!di || !di->backing_path.dentry)

	if (di && di->backing_path.dentry)

		return vfs_getxattr(di->backing_path.dentry, name, value, size);



	if (strcmp(name, "security.selinux"))

		return -ENODATA;



	return vfs_getxattr(di->backing_path.dentry, name, value, size);

	if (!strcmp(d->d_iname, INCFS_PENDING_READS_FILENAME)) {

		stored_value = mi->pending_read_xattr;

		stored_size = mi->pending_read_xattr_size;

	} else if (!strcmp(d->d_iname, INCFS_LOG_FILENAME)) {

		stored_value = mi->log_xattr;

		stored_size = mi->log_xattr_size;

	} else {

		return -ENODATA;

	}



	if (!stored_value)

		return -ENODATA;



	if (stored_size > size)

		return -E2BIG;



	memcpy(value, stored_value, stored_size);

	return stored_size;



}





static ssize_t incfs_setxattr(struct dentry *d, const char *name,

			const void *value, size_t size, int flags)

{

	struct dentry_info *di = get_incfs_dentry(d);

	struct mount_info *mi = get_mount_info(d->d_sb);

	void **stored_value;

	size_t *stored_size;



	if (di && di->backing_path.dentry)

		return vfs_setxattr(di->backing_path.dentry, name, value, size,

				    flags);



	if (strcmp(name, "security.selinux"))

		return -ENODATA;



	if (size > INCFS_MAX_FILE_ATTR_SIZE)

		return -E2BIG;



	if (!strcmp(d->d_iname, INCFS_PENDING_READS_FILENAME)) {

		stored_value = &mi->pending_read_xattr;

		stored_size = &mi->pending_read_xattr_size;

	} else if (!strcmp(d->d_iname, INCFS_LOG_FILENAME)) {

		stored_value = &mi->log_xattr;

		stored_size = &mi->log_xattr_size;

	} else {

		return -ENODATA;

	}



	kfree (*stored_value);

	*stored_value = kzalloc(size, GFP_NOFS);

	if (!*stored_value)

		return -ENOMEM;



	memcpy(*stored_value, value, size);

	*stored_size = size;

	return 0;

}



static ssize_t incfs_listxattr(struct dentry *d, char *list, size_t size)