Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[cascardo/linux.git] / fs / overlayfs / super.c

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 0ffc8da..bcf3965 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -273,12 +273,11 @@ static bool ovl_is_opaquedir(struct dentry *dentry)
 {
        int res;
        char val;
-       struct inode *inode = dentry->d_inode;
 
-       if (!S_ISDIR(inode->i_mode) || !(inode->i_opflags & IOP_XATTR))
+       if (!d_is_dir(dentry))
                return false;
 
-       res = __vfs_getxattr(dentry, inode, OVL_XATTR_OPAQUE, &val, 1);
+       res = vfs_getxattr(dentry, OVL_XATTR_OPAQUE, &val, 1);
        if (res == 1 && val == 'y')
                return true;
 
@@ -419,16 +418,12 @@ static bool ovl_dentry_weird(struct dentry *dentry)
                                  DCACHE_OP_COMPARE);
 }
 
-static inline struct dentry *ovl_lookup_real(struct super_block *ovl_sb,
-                                            struct dentry *dir,
+static inline struct dentry *ovl_lookup_real(struct dentry *dir,
                                             const struct qstr *name)
 {
-       const struct cred *old_cred;
        struct dentry *dentry;
 
-       old_cred = ovl_override_creds(ovl_sb);
        dentry = lookup_one_len_unlocked(name->name, dir, name->len);
-       revert_creds(old_cred);
 
        if (IS_ERR(dentry)) {
                if (PTR_ERR(dentry) == -ENOENT)
@@ -469,6 +464,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
                          unsigned int flags)
 {
        struct ovl_entry *oe;
+       const struct cred *old_cred;
        struct ovl_entry *poe = dentry->d_parent->d_fsdata;
        struct path *stack = NULL;
        struct dentry *upperdir, *upperdentry = NULL;
@@ -479,9 +475,10 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
        unsigned int i;
        int err;
 
+       old_cred = ovl_override_creds(dentry->d_sb);
        upperdir = ovl_upperdentry_dereference(poe);
        if (upperdir) {
-               this = ovl_lookup_real(dentry->d_sb, upperdir, &dentry->d_name);
+               this = ovl_lookup_real(upperdir, &dentry->d_name);
                err = PTR_ERR(this);
                if (IS_ERR(this))
                        goto out;
@@ -514,8 +511,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
                bool opaque = false;
                struct path lowerpath = poe->lowerstack[i];
 
-               this = ovl_lookup_real(dentry->d_sb,
-                                      lowerpath.dentry, &dentry->d_name);
+               this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name);
                err = PTR_ERR(this);
                if (IS_ERR(this)) {
                        /*
@@ -588,6 +584,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
                ovl_copyattr(realdentry->d_inode, inode);
        }
 
+       revert_creds(old_cred);
        oe->opaque = upperopaque;
        oe->__upperdentry = upperdentry;
        memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr);
@@ -606,6 +603,7 @@ out_put:
 out_put_upper:
        dput(upperdentry);
 out:
+       revert_creds(old_cred);
        return ERR_PTR(err);
 }
 
@@ -834,6 +832,19 @@ retry:
                if (err)
                        goto out_dput;
 
+               /*
+                * Try to remove POSIX ACL xattrs from workdir.  We are good if:
+                *
+                * a) success (there was a POSIX ACL xattr and was removed)
+                * b) -ENODATA (there was no POSIX ACL xattr)
+                * c) -EOPNOTSUPP (POSIX ACL xattrs are not supported)
+                *
+                * There are various other error values that could effectively
+                * mean that the xattr doesn't exist (e.g. -ERANGE is returned
+                * if the xattr name is too long), but the set of filesystems
+                * allowed as upper are limited to "normal" ones, where checking
+                * for the above two errors is sufficient.
+                */
                err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);
                if (err && err != -ENODATA && err != -EOPNOTSUPP)
                        goto out_dput;