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| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-07-29 12:05:24 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2016-07-29 12:05:24 +0200 |
| commit | d837a49bd57f1ec2f6411efa829fecc34002b110 (patch) | |
| tree | 0de26dde37daa784a9f5cfb24837f0b1d6e6a410 /fs/overlayfs/inode.c | |
| parent | 51f7e52dc943468c6929fa0a82d4afac3c8e9636 (diff) | |
ovl: fix POSIX ACL setting
Setting POSIX ACL needs special handling:
1) Some permission checks are done by ->setxattr() which now uses mounter's
creds ("ovl: do operations on underlying file system in mounter's
context"). These permission checks need to be done with current cred as
well.
2) Setting ACL can fail for various reasons. We do not need to copy up in
these cases.
In the mean time switch to using generic_setxattr.
[Arnd Bergmann] Fix link error without POSIX ACL. posix_acl_from_xattr()
doesn't have a 'static inline' implementation when CONFIG_FS_POSIX_ACL is
disabled, and I could not come up with an obvious way to do it.
This instead avoids the link error by defining two sets of ACL operations
and letting the compiler drop one of the two at compile time depending
on CONFIG_FS_POSIX_ACL. This avoids all references to the ACL code,
also leading to smaller code.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/inode.c')
| -rw-r--r-- | fs/overlayfs/inode.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 6be0d276fd05..f7caf16f9bec 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -190,7 +190,9 @@ static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz) static bool ovl_is_private_xattr(const char *name) { - return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0; +#define OVL_XATTR_PRE_NAME OVL_XATTR_PREFIX "." + return strncmp(name, OVL_XATTR_PRE_NAME, + sizeof(OVL_XATTR_PRE_NAME) - 1) == 0; } int ovl_setxattr(struct dentry *dentry, struct inode *inode, @@ -205,10 +207,6 @@ int ovl_setxattr(struct dentry *dentry, struct inode *inode, if (err) goto out; - err = -EPERM; - if (ovl_is_private_xattr(name)) - goto out_drop_write; - err = ovl_copy_up(dentry); if (err) goto out_drop_write; @@ -389,7 +387,7 @@ static const struct inode_operations ovl_file_inode_operations = { .setattr = ovl_setattr, .permission = ovl_permission, .getattr = ovl_getattr, - .setxattr = ovl_setxattr, + .setxattr = generic_setxattr, .getxattr = ovl_getxattr, .listxattr = ovl_listxattr, .removexattr = ovl_removexattr, @@ -402,7 +400,7 @@ static const struct inode_operations ovl_symlink_inode_operations = { .get_link = ovl_get_link, .readlink = ovl_readlink, .getattr = ovl_getattr, - .setxattr = ovl_setxattr, + .setxattr = generic_setxattr, .getxattr = ovl_getxattr, .listxattr = ovl_listxattr, .removexattr = ovl_removexattr, |