I hit ENOSPC error when creating new file in a newly created ext4
with ea_inode feature enabled, if selinux is enabled and ext4 is
mounted without any selinux context. e.g.
mkfs -t ext4 -O ea_inode -F /dev/sda5
mount /dev/sda5 /mnt/ext4
touch /mnt/ext4/testfile # got ENOSPC here
It turns out that we run out of journal credits in
ext4_xattr_set_handle() when creating new selinux label for the
newly created inode.
This is because that in __ext4_new_inode() we use
__ext4_xattr_set_credits() to calculate the reserved credits for new
xattr, with the 'is_create' argument being true, which implies less
credits in the ea_inode case. But we calculate the required credits
in ext4_xattr_set_handle() with 'is_create' being false, which means
we need more credits if ea_inode feature is enabled. So we don't
have enough credits and error out with ENOSPC.
Fix it by simply calling ext4_xattr_set_handle() with XATTR_CREATE
flag in ext4_initxattrs(), so we end up with requiring less credits
than reserved. The semantic of XATTR_CREATE is "Perform a pure
create, which fails if the named attribute exists already." (from
setxattr(2)), which is fine in this case, because we only call
ext4_initxattrs() on newly created inode.
Fixes: af65207c76ce ("ext4: fix __ext4_new_inode() journal credits calculation")
Cc: Tahsin Erdogan <tahsin@xxxxxxxxxx>
Signed-off-by: Eryu Guan <guaneryu@xxxxxxxxx>
---
fs/ext4/xattr_security.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 629001b28632..197a9d8a15ef 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -43,7 +43,7 @@ ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array,
err = ext4_xattr_set_handle(handle, inode,
EXT4_XATTR_INDEX_SECURITY,
xattr->name, xattr->value,
- xattr->value_len, 0);
+ xattr->value_len, XATTR_CREATE);
if (err < 0)
break;
}
--
2.14.3
