Commit d631abda authored Jun 01, 2014 by Jaegeuk Kim

f2fs: fix recursive lock by f2fs_setxattr



This patch should resolve the following recursive lock.

[<ffffffff8135a9c3>] call_rwsem_down_write_failed+0x13/0x20
[<ffffffffa01749dc>] f2fs_setxattr+0x5c/0xa0 [f2fs]
[<ffffffffa0174c99>] __f2fs_set_acl+0x1b9/0x340 [f2fs]
[<ffffffffa017515a>] f2fs_init_acl+0x4a/0xcb [f2fs]
[<ffffffffa0159abe>] __f2fs_add_link+0x26e/0x780 [f2fs]
[<ffffffffa015d4d8>] f2fs_mkdir+0xb8/0x150 [f2fs]
[<ffffffff811cebd7>] vfs_mkdir+0xb7/0x160
[<ffffffff811cf89b>] SyS_mkdir+0xab/0xe0
[<ffffffff817244bf>] tracesys+0xe1/0xe6
[<ffffffffffffffff>] 0xffffffffffffffff

The call path indicates:
- f2fs_add_link
   : down_write(&fi->i_sem);

 - init_inode_metadata
   - f2fs_init_acl
     - __f2fs_set_acl
       - f2fs_setxattr
         : down_write(&fi->i_sem);

Here we should not call f2fs_setxattr, but __f2fs_setxattr.
But __f2fs_setxattr is a static function in xattr.c, so that I found the other
generic approach to use f2fs_setxattr.

In f2fs_setxattr, the page pointer is only given from init_inode_metadata.
So, this patch adds this condition to avoid this in f2fs_setxattr.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

parent f6238a72

fs/f2fs/xattr.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -156,10 +156,6 @@ static int f2fs_xattr_advise_set(struct dentry dentry, const char name,
		}

		#ifdef CONFIG_F2FS_FS_SECURITY
		static int __f2fs_setxattr(struct inode *inode, int index,
		const char name, const void value, size_t size,
		struct page *ipage, int);

		static int f2fs_initxattrs(struct inode inode, const struct xattr xattr_array,
		void *page)
		{
		@@ -167,7 +163,7 @@ static int f2fs_initxattrs(struct inode inode, const struct xattr xattr_array,
		int err = 0;

		for (xattr = xattr_array; xattr->name != NULL; xattr++) {
		err = __f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
		err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
		xattr->name, xattr->value,
		xattr->value_len, (struct page *)page, 0);
		if (err < 0)
		@@ -603,6 +599,10 @@ int f2fs_setxattr(struct inode inode, int index, const char name,
		struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
		int err;

		/* this case is only from init_inode_metadata */
		if (ipage)
		return __f2fs_setxattr(inode, index, name, value,
		size, ipage, flags);
		f2fs_balance_fs(sbi);

		f2fs_lock_op(sbi);

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