phy: mediatek: Make PHY_MTK_{XSPHY, TPHY} depend on HAS_IOMEM and OF_ADDRESS to fix...

[linux-2.6-microblaze.git] / fs / libfs.c

diff --git a/fs/libfs.c b/fs/libfs.c
index e0d42e9..fc34361 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -20,6 +20,8 @@
 #include <linux/fs_context.h>
 #include <linux/pseudo_fs.h>
 #include <linux/fsnotify.h>
+#include <linux/unicode.h>
+#include <linux/fscrypt.h>
 
 #include <linux/uaccess.h>
 
@@ -1363,3 +1365,88 @@ bool is_empty_dir_inode(struct inode *inode)
        return (inode->i_fop == &empty_dir_operations) &&
                (inode->i_op == &empty_dir_inode_operations);
 }
+
+#ifdef CONFIG_UNICODE
+/*
+ * Determine if the name of a dentry should be casefolded.
+ *
+ * Return: if names will need casefolding
+ */
+static bool needs_casefold(const struct inode *dir)
+{
+       return IS_CASEFOLDED(dir) && dir->i_sb->s_encoding;
+}
+
+/**
+ * generic_ci_d_compare - generic d_compare implementation for casefolding filesystems
+ * @dentry:    dentry whose name we are checking against
+ * @len:       len of name of dentry
+ * @str:       str pointer to name of dentry
+ * @name:      Name to compare against
+ *
+ * Return: 0 if names match, 1 if mismatch, or -ERRNO
+ */
+int generic_ci_d_compare(const struct dentry *dentry, unsigned int len,
+                         const char *str, const struct qstr *name)
+{
+       const struct dentry *parent = READ_ONCE(dentry->d_parent);
+       const struct inode *dir = READ_ONCE(parent->d_inode);
+       const struct super_block *sb = dentry->d_sb;
+       const struct unicode_map *um = sb->s_encoding;
+       struct qstr qstr = QSTR_INIT(str, len);
+       char strbuf[DNAME_INLINE_LEN];
+       int ret;
+
+       if (!dir || !needs_casefold(dir))
+               goto fallback;
+       /*
+        * If the dentry name is stored in-line, then it may be concurrently
+        * modified by a rename.  If this happens, the VFS will eventually retry
+        * the lookup, so it doesn't matter what ->d_compare() returns.
+        * However, it's unsafe to call utf8_strncasecmp() with an unstable
+        * string.  Therefore, we have to copy the name into a temporary buffer.
+        */
+       if (len <= DNAME_INLINE_LEN - 1) {
+               memcpy(strbuf, str, len);
+               strbuf[len] = 0;
+               qstr.name = strbuf;
+               /* prevent compiler from optimizing out the temporary buffer */
+               barrier();
+       }
+       ret = utf8_strncasecmp(um, name, &qstr);
+       if (ret >= 0)
+               return ret;
+
+       if (sb_has_strict_encoding(sb))
+               return -EINVAL;
+fallback:
+       if (len != name->len)
+               return 1;
+       return !!memcmp(str, name->name, len);
+}
+EXPORT_SYMBOL(generic_ci_d_compare);
+
+/**
+ * generic_ci_d_hash - generic d_hash implementation for casefolding filesystems
+ * @dentry:    dentry of the parent directory
+ * @str:       qstr of name whose hash we should fill in
+ *
+ * Return: 0 if hash was successful or unchanged, and -EINVAL on error
+ */
+int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str)
+{
+       const struct inode *dir = READ_ONCE(dentry->d_inode);
+       struct super_block *sb = dentry->d_sb;
+       const struct unicode_map *um = sb->s_encoding;
+       int ret = 0;
+
+       if (!dir || !needs_casefold(dir))
+               return 0;
+
+       ret = utf8_casefold_hash(um, dentry, str);
+       if (ret < 0 && sb_has_strict_encoding(sb))
+               return -EINVAL;
+       return 0;
+}
+EXPORT_SYMBOL(generic_ci_d_hash);
+#endif