ANDROID: Included sdcardfs source code for kernel 3.0
Only included the source code as is for kernel 3.0. Following patches
take care of porting this file system to version 3.10.
Change-Id: I09e76db77cd98a059053ba5b6fd88572a4b75b5b
Signed-off-by: Daniel Campello <campello@google.com>
diff --git a/fs/sdcardfs/dentry.c b/fs/sdcardfs/dentry.c
new file mode 100644
index 0000000..4572a54
--- /dev/null
+++ b/fs/sdcardfs/dentry.c
@@ -0,0 +1,182 @@
+/*
+ * fs/sdcardfs/dentry.c
+ *
+ * Copyright (c) 2013 Samsung Electronics Co. Ltd
+ * Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun,
+ * Sunghwan Yun, Sungjong Seo
+ *
+ * This program has been developed as a stackable file system based on
+ * the WrapFS which written by
+ *
+ * Copyright (c) 1998-2011 Erez Zadok
+ * Copyright (c) 2009 Shrikar Archak
+ * Copyright (c) 2003-2011 Stony Brook University
+ * Copyright (c) 2003-2011 The Research Foundation of SUNY
+ *
+ * This file is dual licensed. It may be redistributed and/or modified
+ * under the terms of the Apache 2.0 License OR version 2 of the GNU
+ * General Public License.
+ */
+
+#include "sdcardfs.h"
+#include "linux/ctype.h"
+
+/*
+ * returns: -ERRNO if error (returned to user)
+ * 0: tell VFS to invalidate dentry
+ * 1: dentry is valid
+ */
+static int sdcardfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ int err = 1;
+ struct path parent_lower_path, lower_path;
+ struct dentry *parent_dentry = NULL;
+ struct dentry *parent_lower_dentry = NULL;
+ struct dentry *lower_cur_parent_dentry = NULL;
+ struct dentry *lower_dentry = NULL;
+
+ if (nd && nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ spin_lock(&dentry->d_lock);
+ if (IS_ROOT(dentry)) {
+ spin_unlock(&dentry->d_lock);
+ return 1;
+ }
+ spin_unlock(&dentry->d_lock);
+
+ /* check uninitialized obb_dentry and
+ * whether the base obbpath has been changed or not */
+ if (is_obbpath_invalid(dentry)) {
+ d_drop(dentry);
+ return 0;
+ }
+
+ parent_dentry = dget_parent(dentry);
+ sdcardfs_get_lower_path(parent_dentry, &parent_lower_path);
+ sdcardfs_get_real_lower(dentry, &lower_path);
+ parent_lower_dentry = parent_lower_path.dentry;
+ lower_dentry = lower_path.dentry;
+ lower_cur_parent_dentry = dget_parent(lower_dentry);
+
+ spin_lock(&lower_dentry->d_lock);
+ if (d_unhashed(lower_dentry)) {
+ spin_unlock(&lower_dentry->d_lock);
+ d_drop(dentry);
+ err = 0;
+ goto out;
+ }
+ spin_unlock(&lower_dentry->d_lock);
+
+ if (parent_lower_dentry != lower_cur_parent_dentry) {
+ d_drop(dentry);
+ err = 0;
+ goto out;
+ }
+
+ if (dentry < lower_dentry) {
+ spin_lock(&dentry->d_lock);
+ spin_lock(&lower_dentry->d_lock);
+ } else {
+ spin_lock(&lower_dentry->d_lock);
+ spin_lock(&dentry->d_lock);
+ }
+
+ if (dentry->d_name.len != lower_dentry->d_name.len) {
+ __d_drop(dentry);
+ err = 0;
+ } else if (strncasecmp(dentry->d_name.name, lower_dentry->d_name.name,
+ dentry->d_name.len) != 0) {
+ __d_drop(dentry);
+ err = 0;
+ }
+
+ if (dentry < lower_dentry) {
+ spin_unlock(&lower_dentry->d_lock);
+ spin_unlock(&dentry->d_lock);
+ } else {
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&lower_dentry->d_lock);
+ }
+
+out:
+ dput(parent_dentry);
+ dput(lower_cur_parent_dentry);
+ sdcardfs_put_lower_path(parent_dentry, &parent_lower_path);
+ sdcardfs_put_real_lower(dentry, &lower_path);
+ return err;
+}
+
+static void sdcardfs_d_release(struct dentry *dentry)
+{
+ /* release and reset the lower paths */
+ if(has_graft_path(dentry)) {
+ sdcardfs_put_reset_orig_path(dentry);
+ }
+ sdcardfs_put_reset_lower_path(dentry);
+ free_dentry_private_data(dentry);
+ return;
+}
+
+static int sdcardfs_hash_ci(const struct dentry *dentry,
+ const struct inode *inode, struct qstr *qstr)
+{
+ /*
+ * This function is copy of vfat_hashi.
+ * FIXME Should we support national language?
+ * Refer to vfat_hashi()
+ * struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io;
+ */
+ const unsigned char *name;
+ unsigned int len;
+ unsigned long hash;
+
+ name = qstr->name;
+ //len = vfat_striptail_len(qstr);
+ len = qstr->len;
+
+ hash = init_name_hash();
+ while (len--)
+ //hash = partial_name_hash(nls_tolower(t, *name++), hash);
+ hash = partial_name_hash(tolower(*name++), hash);
+ qstr->hash = end_name_hash(hash);
+
+ return 0;
+}
+
+/*
+ * Case insensitive compare of two vfat names.
+ */
+static int sdcardfs_cmp_ci(const struct dentry *parent,
+ const struct inode *pinode,
+ const struct dentry *dentry, const struct inode *inode,
+ unsigned int len, const char *str, const struct qstr *name)
+{
+ /* This function is copy of vfat_cmpi */
+ // FIXME Should we support national language?
+ //struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io;
+ //unsigned int alen, blen;
+
+ /* A filename cannot end in '.' or we treat it like it has none */
+ /*
+ alen = vfat_striptail_len(name);
+ blen = __vfat_striptail_len(len, str);
+ if (alen == blen) {
+ if (nls_strnicmp(t, name->name, str, alen) == 0)
+ return 0;
+ }
+ */
+ if (name->len == len) {
+ if (strncasecmp(name->name, str, len) == 0)
+ return 0;
+ }
+ return 1;
+}
+
+const struct dentry_operations sdcardfs_ci_dops = {
+ .d_revalidate = sdcardfs_d_revalidate,
+ .d_release = sdcardfs_d_release,
+ .d_hash = sdcardfs_hash_ci,
+ .d_compare = sdcardfs_cmp_ci,
+};
+