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Commit 2ed2d5b3 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: fix a deadlock during init_acl procedure 



The deadlock is found through the following scenario.

sys_mkdir()
 -> f2fs_add_link()
  -> __f2fs_add_link()
   -> init_inode_metadata()
     : lock_page(inode);
    -> f2fs_init_acl()
     -> f2fs_set_acl()
      -> f2fs_setxattr(..., NULL)
       : This NULL page incurs a deadlock at update_inode_page().

So, likewise f2fs_init_security(), this patch adds a parameter to transfer the
locked inode page to f2fs_setxattr().

Found by Linux File System Verification project (linuxtesting.org).

Reported-by: default avatarAlexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
parent b8b60e1a

fs/f2fs/acl.c

+8 −7
Original line number Diff line number Diff line
@@ -205,7 +205,8 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int type) 
	return acl;

}



static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl)

static int f2fs_set_acl(struct inode *inode, int type,

			struct posix_acl *acl, struct page *ipage)

{

	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

	struct f2fs_inode_info *fi = F2FS_I(inode);
@@ -250,7 +251,7 @@ static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl) 
		}

	}



	error = f2fs_setxattr(inode, name_index, "", value, size, NULL);

	error = f2fs_setxattr(inode, name_index, "", value, size, ipage);



	kfree(value);

	if (!error)
@@ -260,7 +261,7 @@ static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl) 
	return error;

}



int f2fs_init_acl(struct inode *inode, struct inode *dir)

int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage)

{

	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);

	struct posix_acl *acl = NULL;
@@ -280,7 +281,7 @@ int f2fs_init_acl(struct inode *inode, struct inode *dir) 
		goto cleanup;



	if (S_ISDIR(inode->i_mode)) {

		error = f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl);

		error = f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl, ipage);

		if (error)

			goto cleanup;

	}
@@ -288,7 +289,7 @@ int f2fs_init_acl(struct inode *inode, struct inode *dir) 
	if (error < 0)

		return error;

	if (error > 0)

		error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);

		error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, ipage);

cleanup:

	posix_acl_release(acl);

	return error;
@@ -314,7 +315,7 @@ int f2fs_acl_chmod(struct inode *inode) 
	if (error)

		return error;



	error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);

	error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, NULL);

	posix_acl_release(acl);

	return error;

}
@@ -389,7 +390,7 @@ static int f2fs_xattr_set_acl(struct dentry *dentry, const char *name, 
		acl = NULL;

	}



	error = f2fs_set_acl(inode, type, acl);

	error = f2fs_set_acl(inode, type, acl, NULL);



release_and_out:

	posix_acl_release(acl);

fs/f2fs/acl.h

+3 −2
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ struct f2fs_acl_header { 


extern struct posix_acl *f2fs_get_acl(struct inode *, int);

extern int f2fs_acl_chmod(struct inode *);

extern int f2fs_init_acl(struct inode *, struct inode *);

extern int f2fs_init_acl(struct inode *, struct inode *, struct page *);

#else

#define f2fs_check_acl	NULL

#define f2fs_get_acl	NULL
@@ -49,7 +49,8 @@ static inline int f2fs_acl_chmod(struct inode *inode) 
	return 0;

}



static inline int f2fs_init_acl(struct inode *inode, struct inode *dir)

static inline int f2fs_init_acl(struct inode *inode, struct inode *dir,

							struct page *page)

{

	return 0;

}

fs/f2fs/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -346,7 +346,7 @@ static struct page *init_inode_metadata(struct inode *inode, 
				goto error;

		}



		err = f2fs_init_acl(inode, dir);

		err = f2fs_init_acl(inode, dir, page);

		if (err)

			goto error;