ANDROID: sdcardfs: Add sdcardfs filesystem
Bug: 11118565
Bug: 27915347
Bug: 27992761
Bug: 28024488
Bug: 30013843
Bug: 30954918
Bug: 34133558
Bug: 34262585
Bug: 34542611
Bug: 34691169
Bug: 34723223
Bug: 35307857
Bug: 35331000
Bug: 35633782
Bug: 35643557
Bug: 35666680
bug: 35766959
Bug: 35766959
Bug: 35848445
Bug: 36004503
Bug: 36007653
Bug: 36138424
Bug: 36160015
Bug: 37193650
Bug: 37231161
Bug: 37488099
Bug: 37516160
Bug: 38045152
Bug: 38117720
Bug: 38502532
Bug: 62390017
Bug: 63245673
Bug: 63260873
Bug: 63785372
Bug: 64672411
Bug: 70278506
Bug: 72007585
Bug: 73055997
Bug: 73287721
Bug: 75987238
Bug: 77923821
Bug: 78262592
Bug: 111641492
Bug: 111642636
Bug: 111860541
Bug: 120446149
Change-Id: Ic1e01e602ce335d97342be54f3da0c5c65c087cc
Signed-off-by: Daniel Rosenberg <drosen@google.com>
[astrachan: Folded the following changes into this patch:
903cea7ab0b2 ("ANDROID: Included sdcardfs source code for kernel 3.0")
612a725e3d97 ("ANDROID: Port of sdcardfs to 4.4")
e4187c55208b ("ANDROID: Changed type-casting in packagelist management")
cf76072a5cd8 ("ANDROID: sdcardfs: Bring up to date with Android M permissions:")
a43aa502c608 ("ANDROID: sdcardfs: Add support for d_canonical_path")
d8fefbf85af2 ("ANDROID: sdcardfs: remove effectless config option")
416677409336 ("ANDROID: sdcardfs: Remove unused code")
8e49a570d351 ("ANDROID: sdcardfs: remove unneeded __init and __exit")
40ee0e93f1d7 ("ANDROID: sdcardfs: Truncate packages_gid.list on overflow")
b1d9602aa3fe ("ANDROID: sdcardfs: fix itnull.cocci warnings")
60a177f5a167 ("ANDROID: sdcardfs: override umask on mkdir and create")
efb3d2695203 ("ANDROID: sdcardfs: Check for other cases on path lookup")
0da87f63666f ("ANDROID: sdcardfs: Fix locking for permission fix up")
75b93060655e ("ANDROID: sdcardfs: Switch package list to RCU")
657b0a00f497 ("ANDROID: sdcardfs: Added top to sdcardfs_inode_info")
5008d91cba25 ("ANDROID: sdcardfs: fix external storage exporting incorrect uid")
e06c452d0d07 ("ANDROID: sdcardfs: Move directory unlock before touch")
72e5443a2816 ("ANDROID: sdcardfs: User new permission2 functions")
ae8be7da556d ("ANDROID: sdcardfs: Add gid and mask to private mount data")
151a3efe57a6 ("ANDROID: sdcardfs: Use per mount permissions")
cff865a370f3 ("ANDROID: sdcardfs: Switch ->d_inode to d_inode()")
065ac66804bf ("ANDROID: sdcardfs: Fix locking issue with permision fix up")
31ea603eb3c4 ("ANDROID: sdcardfs: use wrappers to access i_mutex")
c25c2f5018a2 ("ANDROID: sdcardfs: add parent pointer into dentry name hash")
58616bb4ec68 ("ANDROID: sdcardfs: get rid of 'parent' argument of ->d_compare()")
1654d7ffdd20 ("ANDROID: sdcardfs: Propagate dentry down to inode_change_ok()")
39335cac1d2f ("ANDROID: sdcardfs: make it use new .rename i_op")
7622bb3fcc79 ("ANDROID: sdcardfs: eliminate the offset argument to ->direct_IO")
843bd7295ee0 ("ANDROID: sdcardfs: Allow non-owners to touch")
e3d74804d174 ("ANDROID: sdcardfs: Refactor configfs interface")
5833eda87a72 ("ANDROID: sdcardfs: add support for user permission isolation")
d83fb1f41dd4 ("ANDROID: sdcardfs: Remove redundant operation")
8767af17c0e5 ("ANDROID: sdcardfs: Add GID Derivation to sdcardfs")
7119d96ad3ee ("ANDROID: sdcardfs: switch to full_name_hash and qstr")
778e02a54859 ("ANDROID: sdcardfs: Switch strcasecmp for internal call")
cd4965d04404 ("ANDROID: sdcardfs: Fix incorrect hash")
40a2ee053505 ("ANDROID: sdcardfs: Add missing path_put")
da5342bac57a ("ANDROID: sdcardfs: Don't bother deleting freelist")
c91857b01e05 ("ANDROID: sdcardfs: implement vm_ops->page_mkwrite")
f62b3906044b ("ANDROID: sdcardfs: support direct-IO (DIO) operations")
c2e216d36d63 ("ANDROID: sdcardfs: Fix case insensitive lookup")
57b92ab6f774 ("ANDROID: sdcardfs: rate limit warning print")
8534cee39a81 ("ANDROID: sdcardfs: Replace get/put with d_lock")
156085b2fccf ("ANDROID: sdcardfs: Use spin_lock_nested")
8a260cabac4e ("ANDROID: sdcardfs: Switch to internal case insensitive compare")
a8d51569573c ("ANDROID: sdcardfs: Use d_invalidate instead of drop_recurisve")
932a6071de63 ("ANDROID: sdcardfs: Get the blocksize from the lower fs")
0ad4c0f87527 ("ANDROID: sdcardfs: declare MODULE_ALIAS_FS")
b97c83b5b683 ("ANDROID: sdcardfs: Use case insensitive hash function")
9920dfb08265 ("ANDROID: sdcardfs: move path_put outside of spinlock")
f9a25348b233 ("ANDROID: sdcardfs: Remove uninformative prints")
720d9030bea1 ("ANDROID: sdcardfs: Fix gid issue")
4cbb7fa6e66c ("ANDROID: sdcardfs: correct order of descriptors")
6cff6cc301ed ("ANDROID: sdcardfs: Fix formatting")
ac2a40412e26 ("ANDROID: sdcardfs: Fix style issues with comments")
2212bb8ec064 ("ANDROID: sdcardfs: remove unneeded null check")
4c1a0add8d21 ("ANDROID: sdcardfs: Use pr_[...] instead of printk")
74535fe211ac ("ANDROID: sdcardfs: Use to kstrout")
e6cf8dffd014 ("ANDROID: sdcardfs: Use seq_puts over seq_printf")
2b1ac93a90b6 ("ANDROID: sdcardfs: Fix style issues in macros")
bab6d117426f ("ANDROID: sdcardfs: remove unnecessary call to do_munmap")
1c0bf09f19b6 ("ANDROID: sdcardfs: copy lower inode attributes in ->ioctl")
42f3db55942b ("ANDROID: sdcardfs: fix ->llseek to update upper and lower offset")
97ad6205055e ("ANDROID: sdcardfs: add read_iter/write_iter opeations")
be9abc81332b ("ANDROID: sdcardfs: use d_splice_alias")
4e90114cb1b4 ("ANDROID: sdcardfs: update module info")
0e1f7ab14924 ("ANDROID: sdcardfs: Directly pass lower file for mmap")
28be4beb43f9 ("ANDROID: sdcardfs: Change cache GID value")
9fc2c452aefe ("ANDROID: sdcardfs: ->iget fixes")
9bb72cf15cbc ("ANDROID: sdcardfs: Don't do d_add for lower fs")
1bc21a04c11b ("ANDROID: sdcardfs: Don't complain in fixup_lower_ownership")
0fb5b10b28a9 ("ANDROID: sdcardfs: Use filesystem specific hash")
30e2f0aadce2 ("ANDROID: sdcardfs: Copy meta-data from lower inode")
f748c7053194 ("ANDROID: sdcardfs: Avoid setting GIDs outside of valid ranges")
3d38f08bacdb ("ANDROID: sdcardfs: Call lower fs's revalidate")
2d1f1c203978 ("ANDROID: sdcardfs: Don't iput if we didn't igrab")
857fc5e717fc ("ANDROID: sdcardfs: fix sdcardfs_destroy_inode for the inode RCU approach")
4fceeccf1d23 ("ANDROID: sdcardfs: Move top to its own struct")
f51470044a15 ("ANDROID: sdcardfs: Check for NULL in revalidate")
8c7f6c97ac81 ("ANDROID: sdcardfs: d_splice_alias can return error values")
17da01b37d61 ("ANDROID: sdcardfs: remove dead function open_flags_to_access_mode()")
16662dd604be ("ANDROID: sdcardfs: use mount_nodev and fix a issue in sdcardfs_kill_sb")
43c0dca6039a ("ANDROID: sdcardfs: Remove unnecessary lock")
48960c25cdc1 ("ANDROID: sdcardfs: override credential for ioctl to lower fs")
5d6410b9a88d ("ANDROID: Sdcardfs: Move gid derivation under flag")
c7dd98431f83 ("ANDROID: sdcardfs: Add default_normal option")
db9bf31a5d86 ("ANDROID: sdcardfs: port to 4.14")
c70c9d1e82d2 ("ANDROID: sdcardfs: Use lower getattr times/size")
04e961477d62 ("ANDROID: sdcardfs: Protect set_top")
1ed04b79d281 ("ANDROID: sdcardfs: Hold i_mutex for i_size_write")
77f52fc10982 ("ANDROID: sdcardfs: Set num in extension_details during make_item")
d71596efa247 ("ANDROID: sdcardfs: fix lock issue on 32 bit/SMP architectures")
ee6b07fced4a ("ANDROID: sdcardfs: Fix sdcardfs to stop creating cases-sensitive duplicate entries.")
ce12807d5b75 ("ANDROID: sdcardfs: Check for private data earlier")
c080450304cd ("ANDROID: sdcardfs: d_make_root calls iput")
900e77796781 ("ANDROID: sdcardfs: Set s_root to NULL after putting")
49092e89ffa4 ("ANDROID: sdcardfs: Don't d_drop in d_revalidate")
e1f978bc9b9c ("ANDROID: sdcardfs: fix potential crash when reserved_mb is not zero")
faa148eaf8ed ("ANDROID: sdcardfs: Check stacked filesystem depth")
6edd721e972c ("ANDROID: sdcardfs: Don't use OVERRIDE_CRED macro")
11ca578b4336 ("ANDROID: sdcardfs: Change current->fs under lock")
83dea6ba6ea7 ("ANDROID: sdcardfs: Use inode iversion helpers")
12064f3a794e ("ANDROID: sdcardfs: Add option to drop unused dentries")
d9fe221bbf84 ("ANDROID: sdcardfs: Add sandbox")
f544ad0b1547 ("ANDROID: sdcardfs: Add option to not link obb")]
Signed-off-by: Alistair Strachan <astrachan@google.com>
diff --git a/fs/sdcardfs/Kconfig b/fs/sdcardfs/Kconfig
new file mode 100644
index 0000000..a1c1033
--- /dev/null
+++ b/fs/sdcardfs/Kconfig
@@ -0,0 +1,13 @@
+config SDCARD_FS
+ tristate "sdcard file system"
+ depends on CONFIGFS_FS
+ default n
+ help
+ Sdcardfs is based on Wrapfs file system.
+
+config SDCARD_FS_FADV_NOACTIVE
+ bool "sdcardfs fadvise noactive support"
+ depends on FADV_NOACTIVE
+ default y
+ help
+ Sdcardfs supports fadvise noactive mode.
diff --git a/fs/sdcardfs/Makefile b/fs/sdcardfs/Makefile
new file mode 100644
index 0000000..b84fbb2
--- /dev/null
+++ b/fs/sdcardfs/Makefile
@@ -0,0 +1,7 @@
+SDCARDFS_VERSION="0.1"
+
+EXTRA_CFLAGS += -DSDCARDFS_VERSION=\"$(SDCARDFS_VERSION)\"
+
+obj-$(CONFIG_SDCARD_FS) += sdcardfs.o
+
+sdcardfs-y := dentry.o file.o inode.o main.o super.o lookup.o mmap.o packagelist.o derived_perm.o
diff --git a/fs/sdcardfs/dentry.c b/fs/sdcardfs/dentry.c
new file mode 100644
index 0000000..cb573f1
--- /dev/null
+++ b/fs/sdcardfs/dentry.c
@@ -0,0 +1,196 @@
+/*
+ * 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, unsigned int flags)
+{
+ 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;
+ struct inode *inode;
+ struct sdcardfs_inode_data *data;
+
+ if (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)) {
+ 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);
+
+ if ((lower_dentry->d_flags & DCACHE_OP_REVALIDATE)) {
+ err = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
+ if (err == 0) {
+ goto out;
+ }
+ }
+
+ spin_lock(&lower_dentry->d_lock);
+ if (d_unhashed(lower_dentry)) {
+ spin_unlock(&lower_dentry->d_lock);
+ err = 0;
+ goto out;
+ }
+ spin_unlock(&lower_dentry->d_lock);
+
+ if (parent_lower_dentry != lower_cur_parent_dentry) {
+ err = 0;
+ goto out;
+ }
+
+ if (dentry < lower_dentry) {
+ spin_lock(&dentry->d_lock);
+ spin_lock_nested(&lower_dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ } else {
+ spin_lock(&lower_dentry->d_lock);
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ }
+
+ if (!qstr_case_eq(&dentry->d_name, &lower_dentry->d_name)) {
+ 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);
+ }
+ if (!err)
+ goto out;
+
+ /* If our top's inode is gone, we may be out of date */
+ inode = igrab(d_inode(dentry));
+ if (inode) {
+ data = top_data_get(SDCARDFS_I(inode));
+ if (!data || data->abandoned) {
+ err = 0;
+ }
+ if (data)
+ data_put(data);
+ iput(inode);
+ }
+
+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;
+}
+
+/* 1 = delete, 0 = cache */
+static int sdcardfs_d_delete(const struct dentry *d)
+{
+ return SDCARDFS_SB(d->d_sb)->options.nocache ? 1 : 0;
+}
+
+static void sdcardfs_d_release(struct dentry *dentry)
+{
+ if (!dentry || !dentry->d_fsdata)
+ return;
+ /* 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);
+}
+
+static int sdcardfs_hash_ci(const struct dentry *dentry,
+ 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 = qstr->len;
+
+ hash = init_name_hash(dentry);
+ while (len--)
+ 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 *dentry,
+ unsigned int len, const char *str, const struct qstr *name)
+{
+ /* FIXME Should we support national language? */
+
+ if (name->len == len) {
+ if (str_n_case_eq(name->name, str, len))
+ return 0;
+ }
+ return 1;
+}
+
+static void sdcardfs_canonical_path(const struct path *path,
+ struct path *actual_path)
+{
+ sdcardfs_get_real_lower(path->dentry, actual_path);
+}
+
+const struct dentry_operations sdcardfs_ci_dops = {
+ .d_revalidate = sdcardfs_d_revalidate,
+ .d_delete = sdcardfs_d_delete,
+ .d_release = sdcardfs_d_release,
+ .d_hash = sdcardfs_hash_ci,
+ .d_compare = sdcardfs_cmp_ci,
+ .d_canonical_path = sdcardfs_canonical_path,
+};
+
diff --git a/fs/sdcardfs/derived_perm.c b/fs/sdcardfs/derived_perm.c
new file mode 100644
index 0000000..78a669c
--- /dev/null
+++ b/fs/sdcardfs/derived_perm.c
@@ -0,0 +1,477 @@
+/*
+ * fs/sdcardfs/derived_perm.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"
+
+/* copy derived state from parent inode */
+static void inherit_derived_state(struct inode *parent, struct inode *child)
+{
+ struct sdcardfs_inode_info *pi = SDCARDFS_I(parent);
+ struct sdcardfs_inode_info *ci = SDCARDFS_I(child);
+
+ ci->data->perm = PERM_INHERIT;
+ ci->data->userid = pi->data->userid;
+ ci->data->d_uid = pi->data->d_uid;
+ ci->data->under_android = pi->data->under_android;
+ ci->data->under_cache = pi->data->under_cache;
+ ci->data->under_obb = pi->data->under_obb;
+}
+
+/* helper function for derived state */
+void setup_derived_state(struct inode *inode, perm_t perm, userid_t userid,
+ uid_t uid)
+{
+ struct sdcardfs_inode_info *info = SDCARDFS_I(inode);
+
+ info->data->perm = perm;
+ info->data->userid = userid;
+ info->data->d_uid = uid;
+ info->data->under_android = false;
+ info->data->under_cache = false;
+ info->data->under_obb = false;
+}
+
+/* While renaming, there is a point where we want the path from dentry,
+ * but the name from newdentry
+ */
+void get_derived_permission_new(struct dentry *parent, struct dentry *dentry,
+ const struct qstr *name)
+{
+ struct sdcardfs_inode_info *info = SDCARDFS_I(d_inode(dentry));
+ struct sdcardfs_inode_info *parent_info = SDCARDFS_I(d_inode(parent));
+ struct sdcardfs_inode_data *parent_data = parent_info->data;
+ appid_t appid;
+ unsigned long user_num;
+ int err;
+ struct qstr q_Android = QSTR_LITERAL("Android");
+ struct qstr q_data = QSTR_LITERAL("data");
+ struct qstr q_sandbox = QSTR_LITERAL("sandbox");
+ struct qstr q_obb = QSTR_LITERAL("obb");
+ struct qstr q_media = QSTR_LITERAL("media");
+ struct qstr q_cache = QSTR_LITERAL("cache");
+
+ /* By default, each inode inherits from its parent.
+ * the properties are maintained on its private fields
+ * because the inode attributes will be modified with that of
+ * its lower inode.
+ * These values are used by our custom permission call instead
+ * of using the inode permissions.
+ */
+
+ inherit_derived_state(d_inode(parent), d_inode(dentry));
+
+ /* Files don't get special labels */
+ if (!S_ISDIR(d_inode(dentry)->i_mode)) {
+ set_top(info, parent_info);
+ return;
+ }
+ /* Derive custom permissions based on parent and current node */
+ switch (parent_data->perm) {
+ case PERM_INHERIT:
+ case PERM_ANDROID_PACKAGE_CACHE:
+ set_top(info, parent_info);
+ break;
+ case PERM_PRE_ROOT:
+ /* Legacy internal layout places users at top level */
+ info->data->perm = PERM_ROOT;
+ err = kstrtoul(name->name, 10, &user_num);
+ if (err)
+ info->data->userid = 0;
+ else
+ info->data->userid = user_num;
+ break;
+ case PERM_ROOT:
+ /* Assume masked off by default. */
+ if (qstr_case_eq(name, &q_Android)) {
+ /* App-specific directories inside; let anyone traverse */
+ info->data->perm = PERM_ANDROID;
+ info->data->under_android = true;
+ } else {
+ set_top(info, parent_info);
+ }
+ break;
+ case PERM_ANDROID:
+ if (qstr_case_eq(name, &q_data)) {
+ /* App-specific directories inside; let anyone traverse */
+ info->data->perm = PERM_ANDROID_DATA;
+ } else if (qstr_case_eq(name, &q_sandbox)) {
+ /* App-specific directories inside; let anyone traverse */
+ info->data->perm = PERM_ANDROID_DATA;
+ } else if (qstr_case_eq(name, &q_obb)) {
+ /* App-specific directories inside; let anyone traverse */
+ info->data->perm = PERM_ANDROID_OBB;
+ info->data->under_obb = true;
+ /* Single OBB directory is always shared */
+ } else if (qstr_case_eq(name, &q_media)) {
+ /* App-specific directories inside; let anyone traverse */
+ info->data->perm = PERM_ANDROID_MEDIA;
+ } else {
+ set_top(info, parent_info);
+ }
+ break;
+ case PERM_ANDROID_OBB:
+ case PERM_ANDROID_DATA:
+ case PERM_ANDROID_MEDIA:
+ info->data->perm = PERM_ANDROID_PACKAGE;
+ appid = get_appid(name->name);
+ if (appid != 0 && !is_excluded(name->name, parent_data->userid))
+ info->data->d_uid =
+ multiuser_get_uid(parent_data->userid, appid);
+ break;
+ case PERM_ANDROID_PACKAGE:
+ if (qstr_case_eq(name, &q_cache)) {
+ info->data->perm = PERM_ANDROID_PACKAGE_CACHE;
+ info->data->under_cache = true;
+ }
+ set_top(info, parent_info);
+ break;
+ }
+}
+
+void get_derived_permission(struct dentry *parent, struct dentry *dentry)
+{
+ get_derived_permission_new(parent, dentry, &dentry->d_name);
+}
+
+static appid_t get_type(const char *name)
+{
+ const char *ext = strrchr(name, '.');
+ appid_t id;
+
+ if (ext && ext[0]) {
+ ext = &ext[1];
+ id = get_ext_gid(ext);
+ return id?:AID_MEDIA_RW;
+ }
+ return AID_MEDIA_RW;
+}
+
+void fixup_lower_ownership(struct dentry *dentry, const char *name)
+{
+ struct path path;
+ struct inode *inode;
+ struct inode *delegated_inode = NULL;
+ int error;
+ struct sdcardfs_inode_info *info;
+ struct sdcardfs_inode_data *info_d;
+ struct sdcardfs_inode_data *info_top;
+ perm_t perm;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ uid_t uid = sbi->options.fs_low_uid;
+ gid_t gid = sbi->options.fs_low_gid;
+ struct iattr newattrs;
+
+ if (!sbi->options.gid_derivation)
+ return;
+
+ info = SDCARDFS_I(d_inode(dentry));
+ info_d = info->data;
+ perm = info_d->perm;
+ if (info_d->under_obb) {
+ perm = PERM_ANDROID_OBB;
+ } else if (info_d->under_cache) {
+ perm = PERM_ANDROID_PACKAGE_CACHE;
+ } else if (perm == PERM_INHERIT) {
+ info_top = top_data_get(info);
+ perm = info_top->perm;
+ data_put(info_top);
+ }
+
+ switch (perm) {
+ case PERM_ROOT:
+ case PERM_ANDROID:
+ case PERM_ANDROID_DATA:
+ case PERM_ANDROID_MEDIA:
+ case PERM_ANDROID_PACKAGE:
+ case PERM_ANDROID_PACKAGE_CACHE:
+ uid = multiuser_get_uid(info_d->userid, uid);
+ break;
+ case PERM_ANDROID_OBB:
+ uid = AID_MEDIA_OBB;
+ break;
+ case PERM_PRE_ROOT:
+ default:
+ break;
+ }
+ switch (perm) {
+ case PERM_ROOT:
+ case PERM_ANDROID:
+ case PERM_ANDROID_DATA:
+ case PERM_ANDROID_MEDIA:
+ if (S_ISDIR(d_inode(dentry)->i_mode))
+ gid = multiuser_get_uid(info_d->userid, AID_MEDIA_RW);
+ else
+ gid = multiuser_get_uid(info_d->userid, get_type(name));
+ break;
+ case PERM_ANDROID_OBB:
+ gid = AID_MEDIA_OBB;
+ break;
+ case PERM_ANDROID_PACKAGE:
+ if (uid_is_app(info_d->d_uid))
+ gid = multiuser_get_ext_gid(info_d->d_uid);
+ else
+ gid = multiuser_get_uid(info_d->userid, AID_MEDIA_RW);
+ break;
+ case PERM_ANDROID_PACKAGE_CACHE:
+ if (uid_is_app(info_d->d_uid))
+ gid = multiuser_get_ext_cache_gid(info_d->d_uid);
+ else
+ gid = multiuser_get_uid(info_d->userid, AID_MEDIA_RW);
+ break;
+ case PERM_PRE_ROOT:
+ default:
+ break;
+ }
+
+ sdcardfs_get_lower_path(dentry, &path);
+ inode = d_inode(path.dentry);
+ if (d_inode(path.dentry)->i_gid.val != gid || d_inode(path.dentry)->i_uid.val != uid) {
+retry_deleg:
+ newattrs.ia_valid = ATTR_GID | ATTR_UID | ATTR_FORCE;
+ newattrs.ia_uid = make_kuid(current_user_ns(), uid);
+ newattrs.ia_gid = make_kgid(current_user_ns(), gid);
+ if (!S_ISDIR(inode->i_mode))
+ newattrs.ia_valid |=
+ ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
+ inode_lock(inode);
+ error = security_path_chown(&path, newattrs.ia_uid, newattrs.ia_gid);
+ if (!error)
+ error = notify_change2(path.mnt, path.dentry, &newattrs, &delegated_inode);
+ inode_unlock(inode);
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
+ if (error)
+ pr_debug("sdcardfs: Failed to touch up lower fs gid/uid for %s\n", name);
+ }
+ sdcardfs_put_lower_path(dentry, &path);
+}
+
+static int descendant_may_need_fixup(struct sdcardfs_inode_data *data,
+ struct limit_search *limit)
+{
+ if (data->perm == PERM_ROOT)
+ return (limit->flags & BY_USERID) ?
+ data->userid == limit->userid : 1;
+ if (data->perm == PERM_PRE_ROOT || data->perm == PERM_ANDROID)
+ return 1;
+ return 0;
+}
+
+static int needs_fixup(perm_t perm)
+{
+ if (perm == PERM_ANDROID_DATA || perm == PERM_ANDROID_OBB
+ || perm == PERM_ANDROID_MEDIA)
+ return 1;
+ return 0;
+}
+
+static void __fixup_perms_recursive(struct dentry *dentry, struct limit_search *limit, int depth)
+{
+ struct dentry *child;
+ struct sdcardfs_inode_info *info;
+
+ /*
+ * All paths will terminate their recursion on hitting PERM_ANDROID_OBB,
+ * PERM_ANDROID_MEDIA, or PERM_ANDROID_DATA. This happens at a depth of
+ * at most 3.
+ */
+ WARN(depth > 3, "%s: Max expected depth exceeded!\n", __func__);
+ spin_lock_nested(&dentry->d_lock, depth);
+ if (!d_inode(dentry)) {
+ spin_unlock(&dentry->d_lock);
+ return;
+ }
+ info = SDCARDFS_I(d_inode(dentry));
+
+ if (needs_fixup(info->data->perm)) {
+ list_for_each_entry(child, &dentry->d_subdirs, d_child) {
+ spin_lock_nested(&child->d_lock, depth + 1);
+ if (!(limit->flags & BY_NAME) || qstr_case_eq(&child->d_name, &limit->name)) {
+ if (d_inode(child)) {
+ get_derived_permission(dentry, child);
+ fixup_tmp_permissions(d_inode(child));
+ spin_unlock(&child->d_lock);
+ break;
+ }
+ }
+ spin_unlock(&child->d_lock);
+ }
+ } else if (descendant_may_need_fixup(info->data, limit)) {
+ list_for_each_entry(child, &dentry->d_subdirs, d_child) {
+ __fixup_perms_recursive(child, limit, depth + 1);
+ }
+ }
+ spin_unlock(&dentry->d_lock);
+}
+
+void fixup_perms_recursive(struct dentry *dentry, struct limit_search *limit)
+{
+ __fixup_perms_recursive(dentry, limit, 0);
+}
+
+/* main function for updating derived permission */
+inline void update_derived_permission_lock(struct dentry *dentry)
+{
+ struct dentry *parent;
+
+ if (!dentry || !d_inode(dentry)) {
+ pr_err("sdcardfs: %s: invalid dentry\n", __func__);
+ return;
+ }
+ /* FIXME:
+ * 1. need to check whether the dentry is updated or not
+ * 2. remove the root dentry update
+ */
+ if (!IS_ROOT(dentry)) {
+ parent = dget_parent(dentry);
+ if (parent) {
+ get_derived_permission(parent, dentry);
+ dput(parent);
+ }
+ }
+ fixup_tmp_permissions(d_inode(dentry));
+}
+
+int need_graft_path(struct dentry *dentry)
+{
+ int ret = 0;
+ struct dentry *parent = dget_parent(dentry);
+ struct sdcardfs_inode_info *parent_info = SDCARDFS_I(d_inode(parent));
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ struct qstr obb = QSTR_LITERAL("obb");
+
+ if (!sbi->options.unshared_obb &&
+ parent_info->data->perm == PERM_ANDROID &&
+ qstr_case_eq(&dentry->d_name, &obb)) {
+
+ /* /Android/obb is the base obbpath of DERIVED_UNIFIED */
+ if (!(sbi->options.multiuser == false
+ && parent_info->data->userid == 0)) {
+ ret = 1;
+ }
+ }
+ dput(parent);
+ return ret;
+}
+
+int is_obbpath_invalid(struct dentry *dent)
+{
+ int ret = 0;
+ struct sdcardfs_dentry_info *di = SDCARDFS_D(dent);
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dent->d_sb);
+ char *path_buf, *obbpath_s;
+ int need_put = 0;
+ struct path lower_path;
+
+ /* check the base obbpath has been changed.
+ * this routine can check an uninitialized obb dentry as well.
+ * regarding the uninitialized obb, refer to the sdcardfs_mkdir()
+ */
+ spin_lock(&di->lock);
+ if (di->orig_path.dentry) {
+ if (!di->lower_path.dentry) {
+ ret = 1;
+ } else {
+ path_get(&di->lower_path);
+
+ path_buf = kmalloc(PATH_MAX, GFP_ATOMIC);
+ if (!path_buf) {
+ ret = 1;
+ pr_err("sdcardfs: fail to allocate path_buf in %s.\n", __func__);
+ } else {
+ obbpath_s = d_path(&di->lower_path, path_buf, PATH_MAX);
+ if (d_unhashed(di->lower_path.dentry) ||
+ !str_case_eq(sbi->obbpath_s, obbpath_s)) {
+ ret = 1;
+ }
+ kfree(path_buf);
+ }
+
+ pathcpy(&lower_path, &di->lower_path);
+ need_put = 1;
+ }
+ }
+ spin_unlock(&di->lock);
+ if (need_put)
+ path_put(&lower_path);
+ return ret;
+}
+
+int is_base_obbpath(struct dentry *dentry)
+{
+ int ret = 0;
+ struct dentry *parent = dget_parent(dentry);
+ struct sdcardfs_inode_info *parent_info = SDCARDFS_I(d_inode(parent));
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ struct qstr q_obb = QSTR_LITERAL("obb");
+
+ spin_lock(&SDCARDFS_D(dentry)->lock);
+ if (sbi->options.multiuser) {
+ if (parent_info->data->perm == PERM_PRE_ROOT &&
+ qstr_case_eq(&dentry->d_name, &q_obb)) {
+ ret = 1;
+ }
+ } else if (parent_info->data->perm == PERM_ANDROID &&
+ qstr_case_eq(&dentry->d_name, &q_obb)) {
+ ret = 1;
+ }
+ spin_unlock(&SDCARDFS_D(dentry)->lock);
+ return ret;
+}
+
+/* The lower_path will be stored to the dentry's orig_path
+ * and the base obbpath will be copyed to the lower_path variable.
+ * if an error returned, there's no change in the lower_path
+ * returns: -ERRNO if error (0: no error)
+ */
+int setup_obb_dentry(struct dentry *dentry, struct path *lower_path)
+{
+ int err = 0;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ struct path obbpath;
+
+ /* A local obb dentry must have its own orig_path to support rmdir
+ * and mkdir of itself. Usually, we expect that the sbi->obbpath
+ * is avaiable on this stage.
+ */
+ sdcardfs_set_orig_path(dentry, lower_path);
+
+ err = kern_path(sbi->obbpath_s,
+ LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &obbpath);
+
+ if (!err) {
+ /* the obbpath base has been found */
+ pathcpy(lower_path, &obbpath);
+ } else {
+ /* if the sbi->obbpath is not available, we can optionally
+ * setup the lower_path with its orig_path.
+ * but, the current implementation just returns an error
+ * because the sdcard daemon also regards this case as
+ * a lookup fail.
+ */
+ pr_info("sdcardfs: the sbi->obbpath is not available\n");
+ }
+ return err;
+}
+
+
diff --git a/fs/sdcardfs/file.c b/fs/sdcardfs/file.c
new file mode 100644
index 0000000..271c4c4
--- /dev/null
+++ b/fs/sdcardfs/file.c
@@ -0,0 +1,467 @@
+/*
+ * fs/sdcardfs/file.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"
+#ifdef CONFIG_SDCARD_FS_FADV_NOACTIVE
+#include <linux/backing-dev.h>
+#endif
+
+static ssize_t sdcardfs_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int err;
+ struct file *lower_file;
+ struct dentry *dentry = file->f_path.dentry;
+#ifdef CONFIG_SDCARD_FS_FADV_NOACTIVE
+ struct backing_dev_info *bdi;
+#endif
+
+ lower_file = sdcardfs_lower_file(file);
+
+#ifdef CONFIG_SDCARD_FS_FADV_NOACTIVE
+ if (file->f_mode & FMODE_NOACTIVE) {
+ if (!(lower_file->f_mode & FMODE_NOACTIVE)) {
+ bdi = lower_file->f_mapping->backing_dev_info;
+ lower_file->f_ra.ra_pages = bdi->ra_pages * 2;
+ spin_lock(&lower_file->f_lock);
+ lower_file->f_mode |= FMODE_NOACTIVE;
+ spin_unlock(&lower_file->f_lock);
+ }
+ }
+#endif
+
+ err = vfs_read(lower_file, buf, count, ppos);
+ /* update our inode atime upon a successful lower read */
+ if (err >= 0)
+ fsstack_copy_attr_atime(d_inode(dentry),
+ file_inode(lower_file));
+
+ return err;
+}
+
+static ssize_t sdcardfs_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int err;
+ struct file *lower_file;
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = d_inode(dentry);
+
+ /* check disk space */
+ if (!check_min_free_space(dentry, count, 0)) {
+ pr_err("No minimum free space.\n");
+ return -ENOSPC;
+ }
+
+ lower_file = sdcardfs_lower_file(file);
+ err = vfs_write(lower_file, buf, count, ppos);
+ /* update our inode times+sizes upon a successful lower write */
+ if (err >= 0) {
+ if (sizeof(loff_t) > sizeof(long))
+ inode_lock(inode);
+ fsstack_copy_inode_size(inode, file_inode(lower_file));
+ fsstack_copy_attr_times(inode, file_inode(lower_file));
+ if (sizeof(loff_t) > sizeof(long))
+ inode_unlock(inode);
+ }
+
+ return err;
+}
+
+static int sdcardfs_readdir(struct file *file, struct dir_context *ctx)
+{
+ int err;
+ struct file *lower_file = NULL;
+ struct dentry *dentry = file->f_path.dentry;
+
+ lower_file = sdcardfs_lower_file(file);
+
+ lower_file->f_pos = file->f_pos;
+ err = iterate_dir(lower_file, ctx);
+ file->f_pos = lower_file->f_pos;
+ if (err >= 0) /* copy the atime */
+ fsstack_copy_attr_atime(d_inode(dentry),
+ file_inode(lower_file));
+ return err;
+}
+
+static long sdcardfs_unlocked_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ long err = -ENOTTY;
+ struct file *lower_file;
+ const struct cred *saved_cred = NULL;
+ struct dentry *dentry = file->f_path.dentry;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+
+ lower_file = sdcardfs_lower_file(file);
+
+ /* XXX: use vfs_ioctl if/when VFS exports it */
+ if (!lower_file || !lower_file->f_op)
+ goto out;
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(sbi, SDCARDFS_I(file_inode(file))->data);
+ if (!saved_cred) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ if (lower_file->f_op->unlocked_ioctl)
+ err = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
+
+ /* some ioctls can change inode attributes (EXT2_IOC_SETFLAGS) */
+ if (!err)
+ sdcardfs_copy_and_fix_attrs(file_inode(file),
+ file_inode(lower_file));
+ revert_fsids(saved_cred);
+out:
+ return err;
+}
+
+#ifdef CONFIG_COMPAT
+static long sdcardfs_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ long err = -ENOTTY;
+ struct file *lower_file;
+ const struct cred *saved_cred = NULL;
+ struct dentry *dentry = file->f_path.dentry;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+
+ lower_file = sdcardfs_lower_file(file);
+
+ /* XXX: use vfs_ioctl if/when VFS exports it */
+ if (!lower_file || !lower_file->f_op)
+ goto out;
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(sbi, SDCARDFS_I(file_inode(file))->data);
+ if (!saved_cred) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ if (lower_file->f_op->compat_ioctl)
+ err = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
+
+ revert_fsids(saved_cred);
+out:
+ return err;
+}
+#endif
+
+static int sdcardfs_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ int err = 0;
+ bool willwrite;
+ struct file *lower_file;
+ const struct vm_operations_struct *saved_vm_ops = NULL;
+
+ /* this might be deferred to mmap's writepage */
+ willwrite = ((vma->vm_flags | VM_SHARED | VM_WRITE) == vma->vm_flags);
+
+ /*
+ * File systems which do not implement ->writepage may use
+ * generic_file_readonly_mmap as their ->mmap op. If you call
+ * generic_file_readonly_mmap with VM_WRITE, you'd get an -EINVAL.
+ * But we cannot call the lower ->mmap op, so we can't tell that
+ * writeable mappings won't work. Therefore, our only choice is to
+ * check if the lower file system supports the ->writepage, and if
+ * not, return EINVAL (the same error that
+ * generic_file_readonly_mmap returns in that case).
+ */
+ lower_file = sdcardfs_lower_file(file);
+ if (willwrite && !lower_file->f_mapping->a_ops->writepage) {
+ err = -EINVAL;
+ pr_err("sdcardfs: lower file system does not support writeable mmap\n");
+ goto out;
+ }
+
+ /*
+ * find and save lower vm_ops.
+ *
+ * XXX: the VFS should have a cleaner way of finding the lower vm_ops
+ */
+ if (!SDCARDFS_F(file)->lower_vm_ops) {
+ err = lower_file->f_op->mmap(lower_file, vma);
+ if (err) {
+ pr_err("sdcardfs: lower mmap failed %d\n", err);
+ goto out;
+ }
+ saved_vm_ops = vma->vm_ops; /* save: came from lower ->mmap */
+ }
+
+ /*
+ * Next 3 lines are all I need from generic_file_mmap. I definitely
+ * don't want its test for ->readpage which returns -ENOEXEC.
+ */
+ file_accessed(file);
+ vma->vm_ops = &sdcardfs_vm_ops;
+
+ file->f_mapping->a_ops = &sdcardfs_aops; /* set our aops */
+ if (!SDCARDFS_F(file)->lower_vm_ops) /* save for our ->fault */
+ SDCARDFS_F(file)->lower_vm_ops = saved_vm_ops;
+ vma->vm_private_data = file;
+ get_file(lower_file);
+ vma->vm_file = lower_file;
+
+out:
+ return err;
+}
+
+static int sdcardfs_open(struct inode *inode, struct file *file)
+{
+ int err = 0;
+ struct file *lower_file = NULL;
+ struct path lower_path;
+ struct dentry *dentry = file->f_path.dentry;
+ struct dentry *parent = dget_parent(dentry);
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ const struct cred *saved_cred = NULL;
+
+ /* don't open unhashed/deleted files */
+ if (d_unhashed(dentry)) {
+ err = -ENOENT;
+ goto out_err;
+ }
+
+ if (!check_caller_access_to_name(d_inode(parent), &dentry->d_name)) {
+ err = -EACCES;
+ goto out_err;
+ }
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(sbi, SDCARDFS_I(inode)->data);
+ if (!saved_cred) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+
+ file->private_data =
+ kzalloc(sizeof(struct sdcardfs_file_info), GFP_KERNEL);
+ if (!SDCARDFS_F(file)) {
+ err = -ENOMEM;
+ goto out_revert_cred;
+ }
+
+ /* open lower object and link sdcardfs's file struct to lower's */
+ sdcardfs_get_lower_path(file->f_path.dentry, &lower_path);
+ lower_file = dentry_open(&lower_path, file->f_flags, current_cred());
+ path_put(&lower_path);
+ if (IS_ERR(lower_file)) {
+ err = PTR_ERR(lower_file);
+ lower_file = sdcardfs_lower_file(file);
+ if (lower_file) {
+ sdcardfs_set_lower_file(file, NULL);
+ fput(lower_file); /* fput calls dput for lower_dentry */
+ }
+ } else {
+ sdcardfs_set_lower_file(file, lower_file);
+ }
+
+ if (err)
+ kfree(SDCARDFS_F(file));
+ else
+ sdcardfs_copy_and_fix_attrs(inode, sdcardfs_lower_inode(inode));
+
+out_revert_cred:
+ revert_fsids(saved_cred);
+out_err:
+ dput(parent);
+ return err;
+}
+
+static int sdcardfs_flush(struct file *file, fl_owner_t id)
+{
+ int err = 0;
+ struct file *lower_file = NULL;
+
+ lower_file = sdcardfs_lower_file(file);
+ if (lower_file && lower_file->f_op && lower_file->f_op->flush) {
+ filemap_write_and_wait(file->f_mapping);
+ err = lower_file->f_op->flush(lower_file, id);
+ }
+
+ return err;
+}
+
+/* release all lower object references & free the file info structure */
+static int sdcardfs_file_release(struct inode *inode, struct file *file)
+{
+ struct file *lower_file;
+
+ lower_file = sdcardfs_lower_file(file);
+ if (lower_file) {
+ sdcardfs_set_lower_file(file, NULL);
+ fput(lower_file);
+ }
+
+ kfree(SDCARDFS_F(file));
+ return 0;
+}
+
+static int sdcardfs_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ int err;
+ struct file *lower_file;
+ struct path lower_path;
+ struct dentry *dentry = file->f_path.dentry;
+
+ err = __generic_file_fsync(file, start, end, datasync);
+ if (err)
+ goto out;
+
+ lower_file = sdcardfs_lower_file(file);
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ err = vfs_fsync_range(lower_file, start, end, datasync);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+out:
+ return err;
+}
+
+static int sdcardfs_fasync(int fd, struct file *file, int flag)
+{
+ int err = 0;
+ struct file *lower_file = NULL;
+
+ lower_file = sdcardfs_lower_file(file);
+ if (lower_file->f_op && lower_file->f_op->fasync)
+ err = lower_file->f_op->fasync(fd, lower_file, flag);
+
+ return err;
+}
+
+/*
+ * Sdcardfs cannot use generic_file_llseek as ->llseek, because it would
+ * only set the offset of the upper file. So we have to implement our
+ * own method to set both the upper and lower file offsets
+ * consistently.
+ */
+static loff_t sdcardfs_file_llseek(struct file *file, loff_t offset, int whence)
+{
+ int err;
+ struct file *lower_file;
+
+ err = generic_file_llseek(file, offset, whence);
+ if (err < 0)
+ goto out;
+
+ lower_file = sdcardfs_lower_file(file);
+ err = generic_file_llseek(lower_file, offset, whence);
+
+out:
+ return err;
+}
+
+/*
+ * Sdcardfs read_iter, redirect modified iocb to lower read_iter
+ */
+ssize_t sdcardfs_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ int err;
+ struct file *file = iocb->ki_filp, *lower_file;
+
+ lower_file = sdcardfs_lower_file(file);
+ if (!lower_file->f_op->read_iter) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ get_file(lower_file); /* prevent lower_file from being released */
+ iocb->ki_filp = lower_file;
+ err = lower_file->f_op->read_iter(iocb, iter);
+ iocb->ki_filp = file;
+ fput(lower_file);
+ /* update upper inode atime as needed */
+ if (err >= 0 || err == -EIOCBQUEUED)
+ fsstack_copy_attr_atime(file->f_path.dentry->d_inode,
+ file_inode(lower_file));
+out:
+ return err;
+}
+
+/*
+ * Sdcardfs write_iter, redirect modified iocb to lower write_iter
+ */
+ssize_t sdcardfs_write_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ int err;
+ struct file *file = iocb->ki_filp, *lower_file;
+ struct inode *inode = file->f_path.dentry->d_inode;
+
+ lower_file = sdcardfs_lower_file(file);
+ if (!lower_file->f_op->write_iter) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ get_file(lower_file); /* prevent lower_file from being released */
+ iocb->ki_filp = lower_file;
+ err = lower_file->f_op->write_iter(iocb, iter);
+ iocb->ki_filp = file;
+ fput(lower_file);
+ /* update upper inode times/sizes as needed */
+ if (err >= 0 || err == -EIOCBQUEUED) {
+ if (sizeof(loff_t) > sizeof(long))
+ inode_lock(inode);
+ fsstack_copy_inode_size(inode, file_inode(lower_file));
+ fsstack_copy_attr_times(inode, file_inode(lower_file));
+ if (sizeof(loff_t) > sizeof(long))
+ inode_unlock(inode);
+ }
+out:
+ return err;
+}
+
+const struct file_operations sdcardfs_main_fops = {
+ .llseek = generic_file_llseek,
+ .read = sdcardfs_read,
+ .write = sdcardfs_write,
+ .unlocked_ioctl = sdcardfs_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = sdcardfs_compat_ioctl,
+#endif
+ .mmap = sdcardfs_mmap,
+ .open = sdcardfs_open,
+ .flush = sdcardfs_flush,
+ .release = sdcardfs_file_release,
+ .fsync = sdcardfs_fsync,
+ .fasync = sdcardfs_fasync,
+ .read_iter = sdcardfs_read_iter,
+ .write_iter = sdcardfs_write_iter,
+};
+
+/* trimmed directory options */
+const struct file_operations sdcardfs_dir_fops = {
+ .llseek = sdcardfs_file_llseek,
+ .read = generic_read_dir,
+ .iterate = sdcardfs_readdir,
+ .unlocked_ioctl = sdcardfs_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = sdcardfs_compat_ioctl,
+#endif
+ .open = sdcardfs_open,
+ .release = sdcardfs_file_release,
+ .flush = sdcardfs_flush,
+ .fsync = sdcardfs_fsync,
+ .fasync = sdcardfs_fasync,
+};
diff --git a/fs/sdcardfs/inode.c b/fs/sdcardfs/inode.c
new file mode 100644
index 0000000..4dd681e
--- /dev/null
+++ b/fs/sdcardfs/inode.c
@@ -0,0 +1,821 @@
+/*
+ * fs/sdcardfs/inode.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/fs_struct.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/task.h>
+
+const struct cred *override_fsids(struct sdcardfs_sb_info *sbi,
+ struct sdcardfs_inode_data *data)
+{
+ struct cred *cred;
+ const struct cred *old_cred;
+ uid_t uid;
+
+ cred = prepare_creds();
+ if (!cred)
+ return NULL;
+
+ if (sbi->options.gid_derivation) {
+ if (data->under_obb)
+ uid = AID_MEDIA_OBB;
+ else
+ uid = multiuser_get_uid(data->userid, sbi->options.fs_low_uid);
+ } else {
+ uid = sbi->options.fs_low_uid;
+ }
+ cred->fsuid = make_kuid(&init_user_ns, uid);
+ cred->fsgid = make_kgid(&init_user_ns, sbi->options.fs_low_gid);
+
+ old_cred = override_creds(cred);
+
+ return old_cred;
+}
+
+void revert_fsids(const struct cred *old_cred)
+{
+ const struct cred *cur_cred;
+
+ cur_cred = current->cred;
+ revert_creds(old_cred);
+ put_cred(cur_cred);
+}
+
+static int sdcardfs_create(struct inode *dir, struct dentry *dentry,
+ umode_t mode, bool want_excl)
+{
+ int err;
+ struct dentry *lower_dentry;
+ struct vfsmount *lower_dentry_mnt;
+ struct dentry *lower_parent_dentry = NULL;
+ struct path lower_path;
+ const struct cred *saved_cred = NULL;
+ struct fs_struct *saved_fs;
+ struct fs_struct *copied_fs;
+
+ if (!check_caller_access_to_name(dir, &dentry->d_name)) {
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(SDCARDFS_SB(dir->i_sb),
+ SDCARDFS_I(dir)->data);
+ if (!saved_cred)
+ return -ENOMEM;
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_dentry_mnt = lower_path.mnt;
+ lower_parent_dentry = lock_parent(lower_dentry);
+
+ /* set last 16bytes of mode field to 0664 */
+ mode = (mode & S_IFMT) | 00664;
+
+ /* temporarily change umask for lower fs write */
+ saved_fs = current->fs;
+ copied_fs = copy_fs_struct(current->fs);
+ if (!copied_fs) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+ copied_fs->umask = 0;
+ task_lock(current);
+ current->fs = copied_fs;
+ task_unlock(current);
+
+ err = vfs_create2(lower_dentry_mnt, d_inode(lower_parent_dentry), lower_dentry, mode, want_excl);
+ if (err)
+ goto out;
+
+ err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path,
+ SDCARDFS_I(dir)->data->userid);
+ if (err)
+ goto out;
+ fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir));
+ fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry));
+ fixup_lower_ownership(dentry, dentry->d_name.name);
+
+out:
+ task_lock(current);
+ current->fs = saved_fs;
+ task_unlock(current);
+ free_fs_struct(copied_fs);
+out_unlock:
+ unlock_dir(lower_parent_dentry);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ revert_fsids(saved_cred);
+out_eacces:
+ return err;
+}
+
+static int sdcardfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ int err;
+ struct dentry *lower_dentry;
+ struct vfsmount *lower_mnt;
+ struct inode *lower_dir_inode = sdcardfs_lower_inode(dir);
+ struct dentry *lower_dir_dentry;
+ struct path lower_path;
+ const struct cred *saved_cred = NULL;
+
+ if (!check_caller_access_to_name(dir, &dentry->d_name)) {
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(SDCARDFS_SB(dir->i_sb),
+ SDCARDFS_I(dir)->data);
+ if (!saved_cred)
+ return -ENOMEM;
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_mnt = lower_path.mnt;
+ dget(lower_dentry);
+ lower_dir_dentry = lock_parent(lower_dentry);
+
+ err = vfs_unlink2(lower_mnt, lower_dir_inode, lower_dentry, NULL);
+
+ /*
+ * Note: unlinking on top of NFS can cause silly-renamed files.
+ * Trying to delete such files results in EBUSY from NFS
+ * below. Silly-renamed files will get deleted by NFS later on, so
+ * we just need to detect them here and treat such EBUSY errors as
+ * if the upper file was successfully deleted.
+ */
+ if (err == -EBUSY && lower_dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ err = 0;
+ if (err)
+ goto out;
+ fsstack_copy_attr_times(dir, lower_dir_inode);
+ fsstack_copy_inode_size(dir, lower_dir_inode);
+ set_nlink(d_inode(dentry),
+ sdcardfs_lower_inode(d_inode(dentry))->i_nlink);
+ d_inode(dentry)->i_ctime = dir->i_ctime;
+ d_drop(dentry); /* this is needed, else LTP fails (VFS won't do it) */
+out:
+ unlock_dir(lower_dir_dentry);
+ dput(lower_dentry);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ revert_fsids(saved_cred);
+out_eacces:
+ return err;
+}
+
+static int touch(char *abs_path, mode_t mode)
+{
+ struct file *filp = filp_open(abs_path, O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW, mode);
+
+ if (IS_ERR(filp)) {
+ if (PTR_ERR(filp) == -EEXIST) {
+ return 0;
+ } else {
+ pr_err("sdcardfs: failed to open(%s): %ld\n",
+ abs_path, PTR_ERR(filp));
+ return PTR_ERR(filp);
+ }
+ }
+ filp_close(filp, current->files);
+ return 0;
+}
+
+static int sdcardfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ int err;
+ int make_nomedia_in_obb = 0;
+ struct dentry *lower_dentry;
+ struct vfsmount *lower_mnt;
+ struct dentry *lower_parent_dentry = NULL;
+ struct dentry *parent_dentry = NULL;
+ struct path lower_path;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ const struct cred *saved_cred = NULL;
+ struct sdcardfs_inode_data *pd = SDCARDFS_I(dir)->data;
+ int touch_err = 0;
+ struct fs_struct *saved_fs;
+ struct fs_struct *copied_fs;
+ struct qstr q_obb = QSTR_LITERAL("obb");
+ struct qstr q_data = QSTR_LITERAL("data");
+
+ if (!check_caller_access_to_name(dir, &dentry->d_name)) {
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(SDCARDFS_SB(dir->i_sb),
+ SDCARDFS_I(dir)->data);
+ if (!saved_cred)
+ return -ENOMEM;
+
+ /* check disk space */
+ parent_dentry = dget_parent(dentry);
+ if (!check_min_free_space(parent_dentry, 0, 1)) {
+ pr_err("sdcardfs: No minimum free space.\n");
+ err = -ENOSPC;
+ dput(parent_dentry);
+ goto out_revert;
+ }
+ dput(parent_dentry);
+
+ /* the lower_dentry is negative here */
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_mnt = lower_path.mnt;
+ lower_parent_dentry = lock_parent(lower_dentry);
+
+ /* set last 16bytes of mode field to 0775 */
+ mode = (mode & S_IFMT) | 00775;
+
+ /* temporarily change umask for lower fs write */
+ saved_fs = current->fs;
+ copied_fs = copy_fs_struct(current->fs);
+ if (!copied_fs) {
+ err = -ENOMEM;
+ unlock_dir(lower_parent_dentry);
+ goto out_unlock;
+ }
+ copied_fs->umask = 0;
+ task_lock(current);
+ current->fs = copied_fs;
+ task_unlock(current);
+
+ err = vfs_mkdir2(lower_mnt, d_inode(lower_parent_dentry), lower_dentry, mode);
+
+ if (err) {
+ unlock_dir(lower_parent_dentry);
+ goto out;
+ }
+
+ /* if it is a local obb dentry, setup it with the base obbpath */
+ if (need_graft_path(dentry)) {
+
+ err = setup_obb_dentry(dentry, &lower_path);
+ if (err) {
+ /* if the sbi->obbpath is not available, the lower_path won't be
+ * changed by setup_obb_dentry() but the lower path is saved to
+ * its orig_path. this dentry will be revalidated later.
+ * but now, the lower_path should be NULL
+ */
+ sdcardfs_put_reset_lower_path(dentry);
+
+ /* the newly created lower path which saved to its orig_path or
+ * the lower_path is the base obbpath.
+ * therefore, an additional path_get is required
+ */
+ path_get(&lower_path);
+ } else
+ make_nomedia_in_obb = 1;
+ }
+
+ err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path, pd->userid);
+ if (err) {
+ unlock_dir(lower_parent_dentry);
+ goto out;
+ }
+
+ fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir));
+ fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry));
+ /* update number of links on parent directory */
+ set_nlink(dir, sdcardfs_lower_inode(dir)->i_nlink);
+ fixup_lower_ownership(dentry, dentry->d_name.name);
+ unlock_dir(lower_parent_dentry);
+ if ((!sbi->options.multiuser) && (qstr_case_eq(&dentry->d_name, &q_obb))
+ && (pd->perm == PERM_ANDROID) && (pd->userid == 0))
+ make_nomedia_in_obb = 1;
+
+ /* When creating /Android/data and /Android/obb, mark them as .nomedia */
+ if (make_nomedia_in_obb ||
+ ((pd->perm == PERM_ANDROID)
+ && (qstr_case_eq(&dentry->d_name, &q_data)))) {
+ revert_fsids(saved_cred);
+ saved_cred = override_fsids(sbi,
+ SDCARDFS_I(d_inode(dentry))->data);
+ if (!saved_cred) {
+ pr_err("sdcardfs: failed to set up .nomedia in %s: %d\n",
+ lower_path.dentry->d_name.name,
+ -ENOMEM);
+ goto out;
+ }
+ set_fs_pwd(current->fs, &lower_path);
+ touch_err = touch(".nomedia", 0664);
+ if (touch_err) {
+ pr_err("sdcardfs: failed to create .nomedia in %s: %d\n",
+ lower_path.dentry->d_name.name,
+ touch_err);
+ goto out;
+ }
+ }
+out:
+ task_lock(current);
+ current->fs = saved_fs;
+ task_unlock(current);
+
+ free_fs_struct(copied_fs);
+out_unlock:
+ sdcardfs_put_lower_path(dentry, &lower_path);
+out_revert:
+ revert_fsids(saved_cred);
+out_eacces:
+ return err;
+}
+
+static int sdcardfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct dentry *lower_dentry;
+ struct dentry *lower_dir_dentry;
+ struct vfsmount *lower_mnt;
+ int err;
+ struct path lower_path;
+ const struct cred *saved_cred = NULL;
+
+ if (!check_caller_access_to_name(dir, &dentry->d_name)) {
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(SDCARDFS_SB(dir->i_sb),
+ SDCARDFS_I(dir)->data);
+ if (!saved_cred)
+ return -ENOMEM;
+
+ /* sdcardfs_get_real_lower(): in case of remove an user's obb dentry
+ * the dentry on the original path should be deleted.
+ */
+ sdcardfs_get_real_lower(dentry, &lower_path);
+
+ lower_dentry = lower_path.dentry;
+ lower_mnt = lower_path.mnt;
+ lower_dir_dentry = lock_parent(lower_dentry);
+
+ err = vfs_rmdir2(lower_mnt, d_inode(lower_dir_dentry), lower_dentry);
+ if (err)
+ goto out;
+
+ d_drop(dentry); /* drop our dentry on success (why not VFS's job?) */
+ if (d_inode(dentry))
+ clear_nlink(d_inode(dentry));
+ fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
+ fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
+ set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
+
+out:
+ unlock_dir(lower_dir_dentry);
+ sdcardfs_put_real_lower(dentry, &lower_path);
+ revert_fsids(saved_cred);
+out_eacces:
+ return err;
+}
+
+/*
+ * The locking rules in sdcardfs_rename are complex. We could use a simpler
+ * superblock-level name-space lock for renames and copy-ups.
+ */
+static int sdcardfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ int err = 0;
+ struct dentry *lower_old_dentry = NULL;
+ struct dentry *lower_new_dentry = NULL;
+ struct dentry *lower_old_dir_dentry = NULL;
+ struct dentry *lower_new_dir_dentry = NULL;
+ struct vfsmount *lower_mnt = NULL;
+ struct dentry *trap = NULL;
+ struct path lower_old_path, lower_new_path;
+ const struct cred *saved_cred = NULL;
+
+ if (flags)
+ return -EINVAL;
+
+ if (!check_caller_access_to_name(old_dir, &old_dentry->d_name) ||
+ !check_caller_access_to_name(new_dir, &new_dentry->d_name)) {
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(SDCARDFS_SB(old_dir->i_sb),
+ SDCARDFS_I(new_dir)->data);
+ if (!saved_cred)
+ return -ENOMEM;
+
+ sdcardfs_get_real_lower(old_dentry, &lower_old_path);
+ sdcardfs_get_lower_path(new_dentry, &lower_new_path);
+ lower_old_dentry = lower_old_path.dentry;
+ lower_new_dentry = lower_new_path.dentry;
+ lower_mnt = lower_old_path.mnt;
+ lower_old_dir_dentry = dget_parent(lower_old_dentry);
+ lower_new_dir_dentry = dget_parent(lower_new_dentry);
+
+ trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+ /* source should not be ancestor of target */
+ if (trap == lower_old_dentry) {
+ err = -EINVAL;
+ goto out;
+ }
+ /* target should not be ancestor of source */
+ if (trap == lower_new_dentry) {
+ err = -ENOTEMPTY;
+ goto out;
+ }
+
+ err = vfs_rename2(lower_mnt,
+ d_inode(lower_old_dir_dentry), lower_old_dentry,
+ d_inode(lower_new_dir_dentry), lower_new_dentry,
+ NULL, 0);
+ if (err)
+ goto out;
+
+ /* Copy attrs from lower dir, but i_uid/i_gid */
+ sdcardfs_copy_and_fix_attrs(new_dir, d_inode(lower_new_dir_dentry));
+ fsstack_copy_inode_size(new_dir, d_inode(lower_new_dir_dentry));
+
+ if (new_dir != old_dir) {
+ sdcardfs_copy_and_fix_attrs(old_dir, d_inode(lower_old_dir_dentry));
+ fsstack_copy_inode_size(old_dir, d_inode(lower_old_dir_dentry));
+ }
+ get_derived_permission_new(new_dentry->d_parent, old_dentry, &new_dentry->d_name);
+ fixup_tmp_permissions(d_inode(old_dentry));
+ fixup_lower_ownership(old_dentry, new_dentry->d_name.name);
+ d_invalidate(old_dentry); /* Can't fixup ownership recursively :( */
+out:
+ unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+ dput(lower_old_dir_dentry);
+ dput(lower_new_dir_dentry);
+ sdcardfs_put_real_lower(old_dentry, &lower_old_path);
+ sdcardfs_put_lower_path(new_dentry, &lower_new_path);
+ revert_fsids(saved_cred);
+out_eacces:
+ return err;
+}
+
+#if 0
+static int sdcardfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+{
+ int err;
+ struct dentry *lower_dentry;
+ struct path lower_path;
+ /* XXX readlink does not requires overriding credential */
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ if (!d_inode(lower_dentry)->i_op ||
+ !d_inode(lower_dentry)->i_op->readlink) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = d_inode(lower_dentry)->i_op->readlink(lower_dentry,
+ buf, bufsiz);
+ if (err < 0)
+ goto out;
+ fsstack_copy_attr_atime(d_inode(dentry), d_inode(lower_dentry));
+
+out:
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ return err;
+}
+#endif
+
+#if 0
+static const char *sdcardfs_follow_link(struct dentry *dentry, void **cookie)
+{
+ char *buf;
+ int len = PAGE_SIZE, err;
+ mm_segment_t old_fs;
+
+ /* This is freed by the put_link method assuming a successful call. */
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf) {
+ buf = ERR_PTR(-ENOMEM);
+ return buf;
+ }
+
+ /* read the symlink, and then we will follow it */
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ err = sdcardfs_readlink(dentry, buf, len);
+ set_fs(old_fs);
+ if (err < 0) {
+ kfree(buf);
+ buf = ERR_PTR(err);
+ } else {
+ buf[err] = '\0';
+ }
+ return *cookie = buf;
+}
+#endif
+
+static int sdcardfs_permission_wrn(struct inode *inode, int mask)
+{
+ WARN_RATELIMIT(1, "sdcardfs does not support permission. Use permission2.\n");
+ return -EINVAL;
+}
+
+void copy_attrs(struct inode *dest, const struct inode *src)
+{
+ dest->i_mode = src->i_mode;
+ dest->i_uid = src->i_uid;
+ dest->i_gid = src->i_gid;
+ dest->i_rdev = src->i_rdev;
+ dest->i_atime = src->i_atime;
+ dest->i_mtime = src->i_mtime;
+ dest->i_ctime = src->i_ctime;
+ dest->i_blkbits = src->i_blkbits;
+ dest->i_flags = src->i_flags;
+#ifdef CONFIG_FS_POSIX_ACL
+ dest->i_acl = src->i_acl;
+#endif
+#ifdef CONFIG_SECURITY
+ dest->i_security = src->i_security;
+#endif
+}
+
+static int sdcardfs_permission(struct vfsmount *mnt, struct inode *inode, int mask)
+{
+ int err;
+ struct inode tmp;
+ struct sdcardfs_inode_data *top = top_data_get(SDCARDFS_I(inode));
+
+ if (IS_ERR(mnt))
+ return PTR_ERR(mnt);
+
+ if (!top)
+ return -EINVAL;
+
+ /*
+ * Permission check on sdcardfs inode.
+ * Calling process should have AID_SDCARD_RW permission
+ * Since generic_permission only needs i_mode, i_uid,
+ * i_gid, and i_sb, we can create a fake inode to pass
+ * this information down in.
+ *
+ * The underlying code may attempt to take locks in some
+ * cases for features we're not using, but if that changes,
+ * locks must be dealt with to avoid undefined behavior.
+ */
+ copy_attrs(&tmp, inode);
+ tmp.i_uid = make_kuid(&init_user_ns, top->d_uid);
+ tmp.i_gid = make_kgid(&init_user_ns, get_gid(mnt, inode->i_sb, top));
+ tmp.i_mode = (inode->i_mode & S_IFMT)
+ | get_mode(mnt, SDCARDFS_I(inode), top);
+ data_put(top);
+ tmp.i_sb = inode->i_sb;
+ if (IS_POSIXACL(inode))
+ pr_warn("%s: This may be undefined behavior...\n", __func__);
+ err = generic_permission(&tmp, mask);
+ return err;
+}
+
+static int sdcardfs_setattr_wrn(struct dentry *dentry, struct iattr *ia)
+{
+ WARN_RATELIMIT(1, "sdcardfs does not support setattr. User setattr2.\n");
+ return -EINVAL;
+}
+
+static int sdcardfs_setattr(struct vfsmount *mnt, struct dentry *dentry, struct iattr *ia)
+{
+ int err;
+ struct dentry *lower_dentry;
+ struct vfsmount *lower_mnt;
+ struct inode *inode;
+ struct inode *lower_inode;
+ struct path lower_path;
+ struct iattr lower_ia;
+ struct dentry *parent;
+ struct inode tmp;
+ struct dentry tmp_d;
+ struct sdcardfs_inode_data *top;
+
+ const struct cred *saved_cred = NULL;
+
+ inode = d_inode(dentry);
+ top = top_data_get(SDCARDFS_I(inode));
+
+ if (!top)
+ return -EINVAL;
+
+ /*
+ * Permission check on sdcardfs inode.
+ * Calling process should have AID_SDCARD_RW permission
+ * Since generic_permission only needs i_mode, i_uid,
+ * i_gid, and i_sb, we can create a fake inode to pass
+ * this information down in.
+ *
+ * The underlying code may attempt to take locks in some
+ * cases for features we're not using, but if that changes,
+ * locks must be dealt with to avoid undefined behavior.
+ *
+ */
+ copy_attrs(&tmp, inode);
+ tmp.i_uid = make_kuid(&init_user_ns, top->d_uid);
+ tmp.i_gid = make_kgid(&init_user_ns, get_gid(mnt, dentry->d_sb, top));
+ tmp.i_mode = (inode->i_mode & S_IFMT)
+ | get_mode(mnt, SDCARDFS_I(inode), top);
+ tmp.i_size = i_size_read(inode);
+ data_put(top);
+ tmp.i_sb = inode->i_sb;
+ tmp_d.d_inode = &tmp;
+
+ /*
+ * Check if user has permission to change dentry. We don't check if
+ * this user can change the lower inode: that should happen when
+ * calling notify_change on the lower inode.
+ */
+ /* prepare our own lower struct iattr (with the lower file) */
+ memcpy(&lower_ia, ia, sizeof(lower_ia));
+ /* Allow touch updating timestamps. A previous permission check ensures
+ * we have write access. Changes to mode, owner, and group are ignored
+ */
+ ia->ia_valid |= ATTR_FORCE;
+ err = setattr_prepare(&tmp_d, ia);
+
+ if (!err) {
+ /* check the Android group ID */
+ parent = dget_parent(dentry);
+ if (!check_caller_access_to_name(d_inode(parent), &dentry->d_name))
+ err = -EACCES;
+ dput(parent);
+ }
+
+ if (err)
+ goto out_err;
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(SDCARDFS_SB(dentry->d_sb),
+ SDCARDFS_I(inode)->data);
+ if (!saved_cred)
+ return -ENOMEM;
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_mnt = lower_path.mnt;
+ lower_inode = sdcardfs_lower_inode(inode);
+
+ if (ia->ia_valid & ATTR_FILE)
+ lower_ia.ia_file = sdcardfs_lower_file(ia->ia_file);
+
+ lower_ia.ia_valid &= ~(ATTR_UID | ATTR_GID | ATTR_MODE);
+
+ /*
+ * If shrinking, first truncate upper level to cancel writing dirty
+ * pages beyond the new eof; and also if its' maxbytes is more
+ * limiting (fail with -EFBIG before making any change to the lower
+ * level). There is no need to vmtruncate the upper level
+ * afterwards in the other cases: we fsstack_copy_inode_size from
+ * the lower level.
+ */
+ if (ia->ia_valid & ATTR_SIZE) {
+ err = inode_newsize_ok(&tmp, ia->ia_size);
+ if (err) {
+ goto out;
+ }
+ truncate_setsize(inode, ia->ia_size);
+ }
+
+ /*
+ * mode change is for clearing setuid/setgid bits. Allow lower fs
+ * to interpret this in its own way.
+ */
+ if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+ lower_ia.ia_valid &= ~ATTR_MODE;
+
+ /* notify the (possibly copied-up) lower inode */
+ /*
+ * Note: we use d_inode(lower_dentry), because lower_inode may be
+ * unlinked (no inode->i_sb and i_ino==0. This happens if someone
+ * tries to open(), unlink(), then ftruncate() a file.
+ */
+ inode_lock(d_inode(lower_dentry));
+ err = notify_change2(lower_mnt, lower_dentry, &lower_ia, /* note: lower_ia */
+ NULL);
+ inode_unlock(d_inode(lower_dentry));
+ if (err)
+ goto out;
+
+ /* get attributes from the lower inode and update derived permissions */
+ sdcardfs_copy_and_fix_attrs(inode, lower_inode);
+
+ /*
+ * Not running fsstack_copy_inode_size(inode, lower_inode), because
+ * VFS should update our inode size, and notify_change on
+ * lower_inode should update its size.
+ */
+
+out:
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ revert_fsids(saved_cred);
+out_err:
+ return err;
+}
+
+static int sdcardfs_fillattr(struct vfsmount *mnt, struct inode *inode,
+ struct kstat *lower_stat, struct kstat *stat)
+{
+ struct sdcardfs_inode_info *info = SDCARDFS_I(inode);
+ struct sdcardfs_inode_data *top = top_data_get(info);
+ struct super_block *sb = inode->i_sb;
+
+ if (!top)
+ return -EINVAL;
+
+ stat->dev = inode->i_sb->s_dev;
+ stat->ino = inode->i_ino;
+ stat->mode = (inode->i_mode & S_IFMT) | get_mode(mnt, info, top);
+ stat->nlink = inode->i_nlink;
+ stat->uid = make_kuid(&init_user_ns, top->d_uid);
+ stat->gid = make_kgid(&init_user_ns, get_gid(mnt, sb, top));
+ stat->rdev = inode->i_rdev;
+ stat->size = lower_stat->size;
+ stat->atime = lower_stat->atime;
+ stat->mtime = lower_stat->mtime;
+ stat->ctime = lower_stat->ctime;
+ stat->blksize = lower_stat->blksize;
+ stat->blocks = lower_stat->blocks;
+ data_put(top);
+ return 0;
+}
+static int sdcardfs_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ struct vfsmount *mnt = path->mnt;
+ struct dentry *dentry = path->dentry;
+ struct kstat lower_stat;
+ struct path lower_path;
+ struct dentry *parent;
+ int err;
+
+ parent = dget_parent(dentry);
+ if (!check_caller_access_to_name(d_inode(parent), &dentry->d_name)) {
+ dput(parent);
+ return -EACCES;
+ }
+ dput(parent);
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ err = vfs_getattr(&lower_path, &lower_stat, request_mask, flags);
+ if (err)
+ goto out;
+ sdcardfs_copy_and_fix_attrs(d_inode(dentry),
+ d_inode(lower_path.dentry));
+ err = sdcardfs_fillattr(mnt, d_inode(dentry), &lower_stat, stat);
+out:
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ return err;
+}
+
+const struct inode_operations sdcardfs_symlink_iops = {
+ .permission2 = sdcardfs_permission,
+ .setattr2 = sdcardfs_setattr,
+ /* XXX Following operations are implemented,
+ * but FUSE(sdcard) or FAT does not support them
+ * These methods are *NOT* perfectly tested.
+ .readlink = sdcardfs_readlink,
+ .follow_link = sdcardfs_follow_link,
+ .put_link = kfree_put_link,
+ */
+};
+
+const struct inode_operations sdcardfs_dir_iops = {
+ .create = sdcardfs_create,
+ .lookup = sdcardfs_lookup,
+ .permission = sdcardfs_permission_wrn,
+ .permission2 = sdcardfs_permission,
+ .unlink = sdcardfs_unlink,
+ .mkdir = sdcardfs_mkdir,
+ .rmdir = sdcardfs_rmdir,
+ .rename = sdcardfs_rename,
+ .setattr = sdcardfs_setattr_wrn,
+ .setattr2 = sdcardfs_setattr,
+ .getattr = sdcardfs_getattr,
+};
+
+const struct inode_operations sdcardfs_main_iops = {
+ .permission = sdcardfs_permission_wrn,
+ .permission2 = sdcardfs_permission,
+ .setattr = sdcardfs_setattr_wrn,
+ .setattr2 = sdcardfs_setattr,
+ .getattr = sdcardfs_getattr,
+};
diff --git a/fs/sdcardfs/lookup.c b/fs/sdcardfs/lookup.c
new file mode 100644
index 0000000..a5c9686
--- /dev/null
+++ b/fs/sdcardfs/lookup.c
@@ -0,0 +1,470 @@
+/*
+ * fs/sdcardfs/lookup.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/delay.h"
+
+/* The dentry cache is just so we have properly sized dentries */
+static struct kmem_cache *sdcardfs_dentry_cachep;
+
+int sdcardfs_init_dentry_cache(void)
+{
+ sdcardfs_dentry_cachep =
+ kmem_cache_create("sdcardfs_dentry",
+ sizeof(struct sdcardfs_dentry_info),
+ 0, SLAB_RECLAIM_ACCOUNT, NULL);
+
+ return sdcardfs_dentry_cachep ? 0 : -ENOMEM;
+}
+
+void sdcardfs_destroy_dentry_cache(void)
+{
+ kmem_cache_destroy(sdcardfs_dentry_cachep);
+}
+
+void free_dentry_private_data(struct dentry *dentry)
+{
+ kmem_cache_free(sdcardfs_dentry_cachep, dentry->d_fsdata);
+ dentry->d_fsdata = NULL;
+}
+
+/* allocate new dentry private data */
+int new_dentry_private_data(struct dentry *dentry)
+{
+ struct sdcardfs_dentry_info *info = SDCARDFS_D(dentry);
+
+ /* use zalloc to init dentry_info.lower_path */
+ info = kmem_cache_zalloc(sdcardfs_dentry_cachep, GFP_ATOMIC);
+ if (!info)
+ return -ENOMEM;
+
+ spin_lock_init(&info->lock);
+ dentry->d_fsdata = info;
+
+ return 0;
+}
+
+struct inode_data {
+ struct inode *lower_inode;
+ userid_t id;
+};
+
+static int sdcardfs_inode_test(struct inode *inode, void *candidate_data/*void *candidate_lower_inode*/)
+{
+ struct inode *current_lower_inode = sdcardfs_lower_inode(inode);
+ userid_t current_userid = SDCARDFS_I(inode)->data->userid;
+
+ if (current_lower_inode == ((struct inode_data *)candidate_data)->lower_inode &&
+ current_userid == ((struct inode_data *)candidate_data)->id)
+ return 1; /* found a match */
+ else
+ return 0; /* no match */
+}
+
+static int sdcardfs_inode_set(struct inode *inode, void *lower_inode)
+{
+ /* we do actual inode initialization in sdcardfs_iget */
+ return 0;
+}
+
+struct inode *sdcardfs_iget(struct super_block *sb, struct inode *lower_inode, userid_t id)
+{
+ struct sdcardfs_inode_info *info;
+ struct inode_data data;
+ struct inode *inode; /* the new inode to return */
+
+ if (!igrab(lower_inode))
+ return ERR_PTR(-ESTALE);
+
+ data.id = id;
+ data.lower_inode = lower_inode;
+ inode = iget5_locked(sb, /* our superblock */
+ /*
+ * hashval: we use inode number, but we can
+ * also use "(unsigned long)lower_inode"
+ * instead.
+ */
+ lower_inode->i_ino, /* hashval */
+ sdcardfs_inode_test, /* inode comparison function */
+ sdcardfs_inode_set, /* inode init function */
+ &data); /* data passed to test+set fxns */
+ if (!inode) {
+ iput(lower_inode);
+ return ERR_PTR(-ENOMEM);
+ }
+ /* if found a cached inode, then just return it (after iput) */
+ if (!(inode->i_state & I_NEW)) {
+ iput(lower_inode);
+ return inode;
+ }
+
+ /* initialize new inode */
+ info = SDCARDFS_I(inode);
+
+ inode->i_ino = lower_inode->i_ino;
+ sdcardfs_set_lower_inode(inode, lower_inode);
+
+ inode_inc_iversion_raw(inode);
+
+ /* use different set of inode ops for symlinks & directories */
+ if (S_ISDIR(lower_inode->i_mode))
+ inode->i_op = &sdcardfs_dir_iops;
+ else if (S_ISLNK(lower_inode->i_mode))
+ inode->i_op = &sdcardfs_symlink_iops;
+ else
+ inode->i_op = &sdcardfs_main_iops;
+
+ /* use different set of file ops for directories */
+ if (S_ISDIR(lower_inode->i_mode))
+ inode->i_fop = &sdcardfs_dir_fops;
+ else
+ inode->i_fop = &sdcardfs_main_fops;
+
+ inode->i_mapping->a_ops = &sdcardfs_aops;
+
+ inode->i_atime.tv_sec = 0;
+ inode->i_atime.tv_nsec = 0;
+ inode->i_mtime.tv_sec = 0;
+ inode->i_mtime.tv_nsec = 0;
+ inode->i_ctime.tv_sec = 0;
+ inode->i_ctime.tv_nsec = 0;
+
+ /* properly initialize special inodes */
+ if (S_ISBLK(lower_inode->i_mode) || S_ISCHR(lower_inode->i_mode) ||
+ S_ISFIFO(lower_inode->i_mode) || S_ISSOCK(lower_inode->i_mode))
+ init_special_inode(inode, lower_inode->i_mode,
+ lower_inode->i_rdev);
+
+ /* all well, copy inode attributes */
+ sdcardfs_copy_and_fix_attrs(inode, lower_inode);
+ fsstack_copy_inode_size(inode, lower_inode);
+
+ unlock_new_inode(inode);
+ return inode;
+}
+
+/*
+ * Helper interpose routine, called directly by ->lookup to handle
+ * spliced dentries.
+ */
+static struct dentry *__sdcardfs_interpose(struct dentry *dentry,
+ struct super_block *sb,
+ struct path *lower_path,
+ userid_t id)
+{
+ struct inode *inode;
+ struct inode *lower_inode;
+ struct super_block *lower_sb;
+ struct dentry *ret_dentry;
+
+ lower_inode = d_inode(lower_path->dentry);
+ lower_sb = sdcardfs_lower_super(sb);
+
+ /* check that the lower file system didn't cross a mount point */
+ if (lower_inode->i_sb != lower_sb) {
+ ret_dentry = ERR_PTR(-EXDEV);
+ goto out;
+ }
+
+ /*
+ * We allocate our new inode below by calling sdcardfs_iget,
+ * which will initialize some of the new inode's fields
+ */
+
+ /* inherit lower inode number for sdcardfs's inode */
+ inode = sdcardfs_iget(sb, lower_inode, id);
+ if (IS_ERR(inode)) {
+ ret_dentry = ERR_CAST(inode);
+ goto out;
+ }
+
+ ret_dentry = d_splice_alias(inode, dentry);
+ dentry = ret_dentry ?: dentry;
+ if (!IS_ERR(dentry))
+ update_derived_permission_lock(dentry);
+out:
+ return ret_dentry;
+}
+
+/*
+ * Connect an sdcardfs inode dentry/inode with several lower ones. This is
+ * the classic stackable file system "vnode interposition" action.
+ *
+ * @dentry: sdcardfs's dentry which interposes on lower one
+ * @sb: sdcardfs's super_block
+ * @lower_path: the lower path (caller does path_get/put)
+ */
+int sdcardfs_interpose(struct dentry *dentry, struct super_block *sb,
+ struct path *lower_path, userid_t id)
+{
+ struct dentry *ret_dentry;
+
+ ret_dentry = __sdcardfs_interpose(dentry, sb, lower_path, id);
+ return PTR_ERR(ret_dentry);
+}
+
+struct sdcardfs_name_data {
+ struct dir_context ctx;
+ const struct qstr *to_find;
+ char *name;
+ bool found;
+};
+
+static int sdcardfs_name_match(struct dir_context *ctx, const char *name,
+ int namelen, loff_t offset, u64 ino, unsigned int d_type)
+{
+ struct sdcardfs_name_data *buf = container_of(ctx, struct sdcardfs_name_data, ctx);
+ struct qstr candidate = QSTR_INIT(name, namelen);
+
+ if (qstr_case_eq(buf->to_find, &candidate)) {
+ memcpy(buf->name, name, namelen);
+ buf->name[namelen] = 0;
+ buf->found = true;
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Main driver function for sdcardfs's lookup.
+ *
+ * Returns: NULL (ok), ERR_PTR if an error occurred.
+ * Fills in lower_parent_path with <dentry,mnt> on success.
+ */
+static struct dentry *__sdcardfs_lookup(struct dentry *dentry,
+ unsigned int flags, struct path *lower_parent_path, userid_t id)
+{
+ int err = 0;
+ struct vfsmount *lower_dir_mnt;
+ struct dentry *lower_dir_dentry = NULL;
+ struct dentry *lower_dentry;
+ const struct qstr *name;
+ struct path lower_path;
+ struct qstr dname;
+ struct dentry *ret_dentry = NULL;
+ struct sdcardfs_sb_info *sbi;
+
+ sbi = SDCARDFS_SB(dentry->d_sb);
+ /* must initialize dentry operations */
+ d_set_d_op(dentry, &sdcardfs_ci_dops);
+
+ if (IS_ROOT(dentry))
+ goto out;
+
+ name = &dentry->d_name;
+
+ /* now start the actual lookup procedure */
+ lower_dir_dentry = lower_parent_path->dentry;
+ lower_dir_mnt = lower_parent_path->mnt;
+
+ /* Use vfs_path_lookup to check if the dentry exists or not */
+ err = vfs_path_lookup(lower_dir_dentry, lower_dir_mnt, name->name, 0,
+ &lower_path);
+ /* check for other cases */
+ if (err == -ENOENT) {
+ struct file *file;
+ const struct cred *cred = current_cred();
+
+ struct sdcardfs_name_data buffer = {
+ .ctx.actor = sdcardfs_name_match,
+ .to_find = name,
+ .name = __getname(),
+ .found = false,
+ };
+
+ if (!buffer.name) {
+ err = -ENOMEM;
+ goto out;
+ }
+ file = dentry_open(lower_parent_path, O_RDONLY, cred);
+ if (IS_ERR(file)) {
+ err = PTR_ERR(file);
+ goto put_name;
+ }
+ err = iterate_dir(file, &buffer.ctx);
+ fput(file);
+ if (err)
+ goto put_name;
+
+ if (buffer.found)
+ err = vfs_path_lookup(lower_dir_dentry,
+ lower_dir_mnt,
+ buffer.name, 0,
+ &lower_path);
+ else
+ err = -ENOENT;
+put_name:
+ __putname(buffer.name);
+ }
+
+ /* no error: handle positive dentries */
+ if (!err) {
+ /* check if the dentry is an obb dentry
+ * if true, the lower_inode must be replaced with
+ * the inode of the graft path
+ */
+
+ if (need_graft_path(dentry)) {
+
+ /* setup_obb_dentry()
+ * The lower_path will be stored to the dentry's orig_path
+ * and the base obbpath will be copyed to the lower_path variable.
+ * if an error returned, there's no change in the lower_path
+ * returns: -ERRNO if error (0: no error)
+ */
+ err = setup_obb_dentry(dentry, &lower_path);
+
+ if (err) {
+ /* if the sbi->obbpath is not available, we can optionally
+ * setup the lower_path with its orig_path.
+ * but, the current implementation just returns an error
+ * because the sdcard daemon also regards this case as
+ * a lookup fail.
+ */
+ pr_info("sdcardfs: base obbpath is not available\n");
+ sdcardfs_put_reset_orig_path(dentry);
+ goto out;
+ }
+ }
+
+ sdcardfs_set_lower_path(dentry, &lower_path);
+ ret_dentry =
+ __sdcardfs_interpose(dentry, dentry->d_sb, &lower_path, id);
+ if (IS_ERR(ret_dentry)) {
+ err = PTR_ERR(ret_dentry);
+ /* path_put underlying path on error */
+ sdcardfs_put_reset_lower_path(dentry);
+ }
+ goto out;
+ }
+
+ /*
+ * We don't consider ENOENT an error, and we want to return a
+ * negative dentry.
+ */
+ if (err && err != -ENOENT)
+ goto out;
+
+ /* instatiate a new negative dentry */
+ dname.name = name->name;
+ dname.len = name->len;
+
+ /* See if the low-level filesystem might want
+ * to use its own hash
+ */
+ lower_dentry = d_hash_and_lookup(lower_dir_dentry, &dname);
+ if (IS_ERR(lower_dentry))
+ return lower_dentry;
+
+ if (!lower_dentry) {
+ /* We called vfs_path_lookup earlier, and did not get a negative
+ * dentry then. Don't confuse the lower filesystem by forcing
+ * one on it now...
+ */
+ err = -ENOENT;
+ goto out;
+ }
+
+ lower_path.dentry = lower_dentry;
+ lower_path.mnt = mntget(lower_dir_mnt);
+ sdcardfs_set_lower_path(dentry, &lower_path);
+
+ /*
+ * If the intent is to create a file, then don't return an error, so
+ * the VFS will continue the process of making this negative dentry
+ * into a positive one.
+ */
+ if (flags & (LOOKUP_CREATE|LOOKUP_RENAME_TARGET))
+ err = 0;
+
+out:
+ if (err)
+ return ERR_PTR(err);
+ return ret_dentry;
+}
+
+/*
+ * On success:
+ * fills dentry object appropriate values and returns NULL.
+ * On fail (== error)
+ * returns error ptr
+ *
+ * @dir : Parent inode.
+ * @dentry : Target dentry to lookup. we should set each of fields.
+ * (dentry->d_name is initialized already)
+ * @nd : nameidata of parent inode
+ */
+struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct dentry *ret = NULL, *parent;
+ struct path lower_parent_path;
+ int err = 0;
+ const struct cred *saved_cred = NULL;
+
+ parent = dget_parent(dentry);
+
+ if (!check_caller_access_to_name(d_inode(parent), &dentry->d_name)) {
+ ret = ERR_PTR(-EACCES);
+ goto out_err;
+ }
+
+ /* save current_cred and override it */
+ saved_cred = override_fsids(SDCARDFS_SB(dir->i_sb),
+ SDCARDFS_I(dir)->data);
+ if (!saved_cred) {
+ ret = ERR_PTR(-ENOMEM);
+ goto out_err;
+ }
+
+ sdcardfs_get_lower_path(parent, &lower_parent_path);
+
+ /* allocate dentry private data. We free it in ->d_release */
+ err = new_dentry_private_data(dentry);
+ if (err) {
+ ret = ERR_PTR(err);
+ goto out;
+ }
+
+ ret = __sdcardfs_lookup(dentry, flags, &lower_parent_path,
+ SDCARDFS_I(dir)->data->userid);
+ if (IS_ERR(ret))
+ goto out;
+ if (ret)
+ dentry = ret;
+ if (d_inode(dentry)) {
+ fsstack_copy_attr_times(d_inode(dentry),
+ sdcardfs_lower_inode(d_inode(dentry)));
+ /* get derived permission */
+ get_derived_permission(parent, dentry);
+ fixup_tmp_permissions(d_inode(dentry));
+ fixup_lower_ownership(dentry, dentry->d_name.name);
+ }
+ /* update parent directory's atime */
+ fsstack_copy_attr_atime(d_inode(parent),
+ sdcardfs_lower_inode(d_inode(parent)));
+
+out:
+ sdcardfs_put_lower_path(parent, &lower_parent_path);
+ revert_fsids(saved_cred);
+out_err:
+ dput(parent);
+ return ret;
+}
diff --git a/fs/sdcardfs/main.c b/fs/sdcardfs/main.c
new file mode 100644
index 0000000..d890c57
--- /dev/null
+++ b/fs/sdcardfs/main.c
@@ -0,0 +1,511 @@
+/*
+ * fs/sdcardfs/main.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/module.h>
+#include <linux/types.h>
+#include <linux/parser.h>
+
+enum {
+ Opt_fsuid,
+ Opt_fsgid,
+ Opt_gid,
+ Opt_debug,
+ Opt_mask,
+ Opt_multiuser,
+ Opt_userid,
+ Opt_reserved_mb,
+ Opt_gid_derivation,
+ Opt_default_normal,
+ Opt_nocache,
+ Opt_unshared_obb,
+ Opt_err,
+};
+
+static const match_table_t sdcardfs_tokens = {
+ {Opt_fsuid, "fsuid=%u"},
+ {Opt_fsgid, "fsgid=%u"},
+ {Opt_gid, "gid=%u"},
+ {Opt_debug, "debug"},
+ {Opt_mask, "mask=%u"},
+ {Opt_userid, "userid=%d"},
+ {Opt_multiuser, "multiuser"},
+ {Opt_gid_derivation, "derive_gid"},
+ {Opt_default_normal, "default_normal"},
+ {Opt_unshared_obb, "unshared_obb"},
+ {Opt_reserved_mb, "reserved_mb=%u"},
+ {Opt_nocache, "nocache"},
+ {Opt_err, NULL}
+};
+
+static int parse_options(struct super_block *sb, char *options, int silent,
+ int *debug, struct sdcardfs_vfsmount_options *vfsopts,
+ struct sdcardfs_mount_options *opts)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+
+ /* by default, we use AID_MEDIA_RW as uid, gid */
+ opts->fs_low_uid = AID_MEDIA_RW;
+ opts->fs_low_gid = AID_MEDIA_RW;
+ vfsopts->mask = 0;
+ opts->multiuser = false;
+ opts->fs_user_id = 0;
+ vfsopts->gid = 0;
+ /* by default, 0MB is reserved */
+ opts->reserved_mb = 0;
+ /* by default, gid derivation is off */
+ opts->gid_derivation = false;
+ opts->default_normal = false;
+ opts->nocache = false;
+
+ *debug = 0;
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+
+ if (!*p)
+ continue;
+
+ token = match_token(p, sdcardfs_tokens, args);
+
+ switch (token) {
+ case Opt_debug:
+ *debug = 1;
+ break;
+ case Opt_fsuid:
+ if (match_int(&args[0], &option))
+ return 0;
+ opts->fs_low_uid = option;
+ break;
+ case Opt_fsgid:
+ if (match_int(&args[0], &option))
+ return 0;
+ opts->fs_low_gid = option;
+ break;
+ case Opt_gid:
+ if (match_int(&args[0], &option))
+ return 0;
+ vfsopts->gid = option;
+ break;
+ case Opt_userid:
+ if (match_int(&args[0], &option))
+ return 0;
+ opts->fs_user_id = option;
+ break;
+ case Opt_mask:
+ if (match_int(&args[0], &option))
+ return 0;
+ vfsopts->mask = option;
+ break;
+ case Opt_multiuser:
+ opts->multiuser = true;
+ break;
+ case Opt_reserved_mb:
+ if (match_int(&args[0], &option))
+ return 0;
+ opts->reserved_mb = option;
+ break;
+ case Opt_gid_derivation:
+ opts->gid_derivation = true;
+ break;
+ case Opt_default_normal:
+ opts->default_normal = true;
+ break;
+ case Opt_nocache:
+ opts->nocache = true;
+ break;
+ case Opt_unshared_obb:
+ opts->unshared_obb = true;
+ break;
+ /* unknown option */
+ default:
+ if (!silent)
+ pr_err("Unrecognized mount option \"%s\" or missing value", p);
+ return -EINVAL;
+ }
+ }
+
+ if (*debug) {
+ pr_info("sdcardfs : options - debug:%d\n", *debug);
+ pr_info("sdcardfs : options - uid:%d\n",
+ opts->fs_low_uid);
+ pr_info("sdcardfs : options - gid:%d\n",
+ opts->fs_low_gid);
+ }
+
+ return 0;
+}
+
+int parse_options_remount(struct super_block *sb, char *options, int silent,
+ struct sdcardfs_vfsmount_options *vfsopts)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+ int debug;
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+
+ if (!*p)
+ continue;
+
+ token = match_token(p, sdcardfs_tokens, args);
+
+ switch (token) {
+ case Opt_debug:
+ debug = 1;
+ break;
+ case Opt_gid:
+ if (match_int(&args[0], &option))
+ return 0;
+ vfsopts->gid = option;
+
+ break;
+ case Opt_mask:
+ if (match_int(&args[0], &option))
+ return 0;
+ vfsopts->mask = option;
+ break;
+ case Opt_unshared_obb:
+ case Opt_default_normal:
+ case Opt_multiuser:
+ case Opt_userid:
+ case Opt_fsuid:
+ case Opt_fsgid:
+ case Opt_reserved_mb:
+ case Opt_gid_derivation:
+ if (!silent)
+ pr_warn("Option \"%s\" can't be changed during remount\n", p);
+ break;
+ /* unknown option */
+ default:
+ if (!silent)
+ pr_err("Unrecognized mount option \"%s\" or missing value", p);
+ return -EINVAL;
+ }
+ }
+
+ if (debug) {
+ pr_info("sdcardfs : options - debug:%d\n", debug);
+ pr_info("sdcardfs : options - gid:%d\n", vfsopts->gid);
+ pr_info("sdcardfs : options - mask:%d\n", vfsopts->mask);
+ }
+
+ return 0;
+}
+
+#if 0
+/*
+ * our custom d_alloc_root work-alike
+ *
+ * we can't use d_alloc_root if we want to use our own interpose function
+ * unchanged, so we simply call our own "fake" d_alloc_root
+ */
+static struct dentry *sdcardfs_d_alloc_root(struct super_block *sb)
+{
+ struct dentry *ret = NULL;
+
+ if (sb) {
+ static const struct qstr name = {
+ .name = "/",
+ .len = 1
+ };
+
+ ret = d_alloc(NULL, &name);
+ if (ret) {
+ d_set_d_op(ret, &sdcardfs_ci_dops);
+ ret->d_sb = sb;
+ ret->d_parent = ret;
+ }
+ }
+ return ret;
+}
+#endif
+
+DEFINE_MUTEX(sdcardfs_super_list_lock);
+EXPORT_SYMBOL_GPL(sdcardfs_super_list_lock);
+LIST_HEAD(sdcardfs_super_list);
+EXPORT_SYMBOL_GPL(sdcardfs_super_list);
+
+/*
+ * There is no need to lock the sdcardfs_super_info's rwsem as there is no
+ * way anyone can have a reference to the superblock at this point in time.
+ */
+static int sdcardfs_read_super(struct vfsmount *mnt, struct super_block *sb,
+ const char *dev_name, void *raw_data, int silent)
+{
+ int err = 0;
+ int debug;
+ struct super_block *lower_sb;
+ struct path lower_path;
+ struct sdcardfs_sb_info *sb_info;
+ struct sdcardfs_vfsmount_options *mnt_opt = mnt->data;
+ struct inode *inode;
+
+ pr_info("sdcardfs version 2.0\n");
+
+ if (!dev_name) {
+ pr_err("sdcardfs: read_super: missing dev_name argument\n");
+ err = -EINVAL;
+ goto out;
+ }
+
+ pr_info("sdcardfs: dev_name -> %s\n", dev_name);
+ pr_info("sdcardfs: options -> %s\n", (char *)raw_data);
+ pr_info("sdcardfs: mnt -> %p\n", mnt);
+
+ /* parse lower path */
+ err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
+ &lower_path);
+ if (err) {
+ pr_err("sdcardfs: error accessing lower directory '%s'\n", dev_name);
+ goto out;
+ }
+
+ /* allocate superblock private data */
+ sb->s_fs_info = kzalloc(sizeof(struct sdcardfs_sb_info), GFP_KERNEL);
+ if (!SDCARDFS_SB(sb)) {
+ pr_crit("sdcardfs: read_super: out of memory\n");
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ sb_info = sb->s_fs_info;
+ /* parse options */
+ err = parse_options(sb, raw_data, silent, &debug, mnt_opt, &sb_info->options);
+ if (err) {
+ pr_err("sdcardfs: invalid options\n");
+ goto out_freesbi;
+ }
+
+ /* set the lower superblock field of upper superblock */
+ lower_sb = lower_path.dentry->d_sb;
+ atomic_inc(&lower_sb->s_active);
+ sdcardfs_set_lower_super(sb, lower_sb);
+
+ sb->s_stack_depth = lower_sb->s_stack_depth + 1;
+ if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
+ pr_err("sdcardfs: maximum fs stacking depth exceeded\n");
+ err = -EINVAL;
+ goto out_sput;
+ }
+
+ /* inherit maxbytes from lower file system */
+ sb->s_maxbytes = lower_sb->s_maxbytes;
+
+ /*
+ * Our c/m/atime granularity is 1 ns because we may stack on file
+ * systems whose granularity is as good.
+ */
+ sb->s_time_gran = 1;
+
+ sb->s_magic = SDCARDFS_SUPER_MAGIC;
+ sb->s_op = &sdcardfs_sops;
+
+ /* get a new inode and allocate our root dentry */
+ inode = sdcardfs_iget(sb, d_inode(lower_path.dentry), 0);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_sput;
+ }
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root) {
+ err = -ENOMEM;
+ goto out_sput;
+ }
+ d_set_d_op(sb->s_root, &sdcardfs_ci_dops);
+
+ /* link the upper and lower dentries */
+ sb->s_root->d_fsdata = NULL;
+ err = new_dentry_private_data(sb->s_root);
+ if (err)
+ goto out_freeroot;
+
+ /* set the lower dentries for s_root */
+ sdcardfs_set_lower_path(sb->s_root, &lower_path);
+
+ /*
+ * No need to call interpose because we already have a positive
+ * dentry, which was instantiated by d_make_root. Just need to
+ * d_rehash it.
+ */
+ d_rehash(sb->s_root);
+
+ /* setup permission policy */
+ sb_info->obbpath_s = kzalloc(PATH_MAX, GFP_KERNEL);
+ mutex_lock(&sdcardfs_super_list_lock);
+ if (sb_info->options.multiuser) {
+ setup_derived_state(d_inode(sb->s_root), PERM_PRE_ROOT,
+ sb_info->options.fs_user_id, AID_ROOT);
+ snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name);
+ } else {
+ setup_derived_state(d_inode(sb->s_root), PERM_ROOT,
+ sb_info->options.fs_user_id, AID_ROOT);
+ snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name);
+ }
+ fixup_tmp_permissions(d_inode(sb->s_root));
+ sb_info->sb = sb;
+ list_add(&sb_info->list, &sdcardfs_super_list);
+ mutex_unlock(&sdcardfs_super_list_lock);
+
+ if (!silent)
+ pr_info("sdcardfs: mounted on top of %s type %s\n",
+ dev_name, lower_sb->s_type->name);
+ goto out; /* all is well */
+
+ /* no longer needed: free_dentry_private_data(sb->s_root); */
+out_freeroot:
+ dput(sb->s_root);
+ sb->s_root = NULL;
+out_sput:
+ /* drop refs we took earlier */
+ atomic_dec(&lower_sb->s_active);
+out_freesbi:
+ kfree(SDCARDFS_SB(sb));
+ sb->s_fs_info = NULL;
+out_free:
+ path_put(&lower_path);
+
+out:
+ return err;
+}
+
+struct sdcardfs_mount_private {
+ struct vfsmount *mnt;
+ const char *dev_name;
+ void *raw_data;
+};
+
+static int __sdcardfs_fill_super(
+ struct super_block *sb,
+ void *_priv, int silent)
+{
+ struct sdcardfs_mount_private *priv = _priv;
+
+ return sdcardfs_read_super(priv->mnt,
+ sb, priv->dev_name, priv->raw_data, silent);
+}
+
+static struct dentry *sdcardfs_mount(struct vfsmount *mnt,
+ struct file_system_type *fs_type, int flags,
+ const char *dev_name, void *raw_data)
+{
+ struct sdcardfs_mount_private priv = {
+ .mnt = mnt,
+ .dev_name = dev_name,
+ .raw_data = raw_data
+ };
+
+ return mount_nodev(fs_type, flags,
+ &priv, __sdcardfs_fill_super);
+}
+
+static struct dentry *sdcardfs_mount_wrn(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *raw_data)
+{
+ WARN(1, "sdcardfs does not support mount. Use mount2.\n");
+ return ERR_PTR(-EINVAL);
+}
+
+void *sdcardfs_alloc_mnt_data(void)
+{
+ return kmalloc(sizeof(struct sdcardfs_vfsmount_options), GFP_KERNEL);
+}
+
+void sdcardfs_kill_sb(struct super_block *sb)
+{
+ struct sdcardfs_sb_info *sbi;
+
+ if (sb->s_magic == SDCARDFS_SUPER_MAGIC && sb->s_fs_info) {
+ sbi = SDCARDFS_SB(sb);
+ mutex_lock(&sdcardfs_super_list_lock);
+ list_del(&sbi->list);
+ mutex_unlock(&sdcardfs_super_list_lock);
+ }
+ kill_anon_super(sb);
+}
+
+static struct file_system_type sdcardfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = SDCARDFS_NAME,
+ .mount = sdcardfs_mount_wrn,
+ .mount2 = sdcardfs_mount,
+ .alloc_mnt_data = sdcardfs_alloc_mnt_data,
+ .kill_sb = sdcardfs_kill_sb,
+ .fs_flags = 0,
+};
+MODULE_ALIAS_FS(SDCARDFS_NAME);
+
+static int __init init_sdcardfs_fs(void)
+{
+ int err;
+
+ pr_info("Registering sdcardfs " SDCARDFS_VERSION "\n");
+
+ err = sdcardfs_init_inode_cache();
+ if (err)
+ goto out;
+ err = sdcardfs_init_dentry_cache();
+ if (err)
+ goto out;
+ err = packagelist_init();
+ if (err)
+ goto out;
+ err = register_filesystem(&sdcardfs_fs_type);
+out:
+ if (err) {
+ sdcardfs_destroy_inode_cache();
+ sdcardfs_destroy_dentry_cache();
+ packagelist_exit();
+ }
+ return err;
+}
+
+static void __exit exit_sdcardfs_fs(void)
+{
+ sdcardfs_destroy_inode_cache();
+ sdcardfs_destroy_dentry_cache();
+ packagelist_exit();
+ unregister_filesystem(&sdcardfs_fs_type);
+ pr_info("Completed sdcardfs module unload\n");
+}
+
+/* Original wrapfs authors */
+MODULE_AUTHOR("Erez Zadok, Filesystems and Storage Lab, Stony Brook University (http://www.fsl.cs.sunysb.edu/)");
+
+/* Original sdcardfs authors */
+MODULE_AUTHOR("Woojoong Lee, Daeho Jeong, Kitae Lee, Yeongjin Gil System Memory Lab., Samsung Electronics");
+
+/* Current maintainer */
+MODULE_AUTHOR("Daniel Rosenberg, Google");
+MODULE_DESCRIPTION("Sdcardfs " SDCARDFS_VERSION);
+MODULE_LICENSE("GPL");
+
+module_init(init_sdcardfs_fs);
+module_exit(exit_sdcardfs_fs);
diff --git a/fs/sdcardfs/mmap.c b/fs/sdcardfs/mmap.c
new file mode 100644
index 0000000..2847c0e
--- /dev/null
+++ b/fs/sdcardfs/mmap.c
@@ -0,0 +1,87 @@
+/*
+ * fs/sdcardfs/mmap.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"
+
+static int sdcardfs_fault(struct vm_fault *vmf)
+{
+ int err;
+ struct file *file;
+ const struct vm_operations_struct *lower_vm_ops;
+
+ file = (struct file *)vmf->vma->vm_private_data;
+ lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
+ BUG_ON(!lower_vm_ops);
+
+ err = lower_vm_ops->fault(vmf);
+ return err;
+}
+
+static void sdcardfs_vm_open(struct vm_area_struct *vma)
+{
+ struct file *file = (struct file *)vma->vm_private_data;
+
+ get_file(file);
+}
+
+static void sdcardfs_vm_close(struct vm_area_struct *vma)
+{
+ struct file *file = (struct file *)vma->vm_private_data;
+
+ fput(file);
+}
+
+static int sdcardfs_page_mkwrite(struct vm_fault *vmf)
+{
+ int err = 0;
+ struct file *file;
+ const struct vm_operations_struct *lower_vm_ops;
+
+ file = (struct file *)vmf->vma->vm_private_data;
+ lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
+ BUG_ON(!lower_vm_ops);
+ if (!lower_vm_ops->page_mkwrite)
+ goto out;
+
+ err = lower_vm_ops->page_mkwrite(vmf);
+out:
+ return err;
+}
+
+static ssize_t sdcardfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+ /*
+ * This function should never be called directly. We need it
+ * to exist, to get past a check in open_check_o_direct(),
+ * which is called from do_last().
+ */
+ return -EINVAL;
+}
+
+const struct address_space_operations sdcardfs_aops = {
+ .direct_IO = sdcardfs_direct_IO,
+};
+
+const struct vm_operations_struct sdcardfs_vm_ops = {
+ .fault = sdcardfs_fault,
+ .page_mkwrite = sdcardfs_page_mkwrite,
+ .open = sdcardfs_vm_open,
+ .close = sdcardfs_vm_close,
+};
diff --git a/fs/sdcardfs/multiuser.h b/fs/sdcardfs/multiuser.h
new file mode 100644
index 0000000..85341e7
--- /dev/null
+++ b/fs/sdcardfs/multiuser.h
@@ -0,0 +1,53 @@
+/*
+ * fs/sdcardfs/multiuser.h
+ *
+ * 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.
+ */
+
+#define AID_USER_OFFSET 100000 /* offset for uid ranges for each user */
+#define AID_APP_START 10000 /* first app user */
+#define AID_APP_END 19999 /* last app user */
+#define AID_CACHE_GID_START 20000 /* start of gids for apps to mark cached data */
+#define AID_EXT_GID_START 30000 /* start of gids for apps to mark external data */
+#define AID_EXT_CACHE_GID_START 40000 /* start of gids for apps to mark external cached data */
+#define AID_EXT_CACHE_GID_END 49999 /* end of gids for apps to mark external cached data */
+#define AID_SHARED_GID_START 50000 /* start of gids for apps in each user to share */
+
+typedef uid_t userid_t;
+typedef uid_t appid_t;
+
+static inline uid_t multiuser_get_uid(userid_t user_id, appid_t app_id)
+{
+ return (user_id * AID_USER_OFFSET) + (app_id % AID_USER_OFFSET);
+}
+
+static inline bool uid_is_app(uid_t uid)
+{
+ appid_t appid = uid % AID_USER_OFFSET;
+
+ return appid >= AID_APP_START && appid <= AID_APP_END;
+}
+
+static inline gid_t multiuser_get_ext_cache_gid(uid_t uid)
+{
+ return uid - AID_APP_START + AID_EXT_CACHE_GID_START;
+}
+
+static inline gid_t multiuser_get_ext_gid(uid_t uid)
+{
+ return uid - AID_APP_START + AID_EXT_GID_START;
+}
diff --git a/fs/sdcardfs/packagelist.c b/fs/sdcardfs/packagelist.c
new file mode 100644
index 0000000..4b9a563
--- /dev/null
+++ b/fs/sdcardfs/packagelist.c
@@ -0,0 +1,882 @@
+/*
+ * fs/sdcardfs/packagelist.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/hashtable.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/radix-tree.h>
+#include <linux/dcache.h>
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/configfs.h>
+
+struct hashtable_entry {
+ struct hlist_node hlist;
+ struct hlist_node dlist; /* for deletion cleanup */
+ struct qstr key;
+ atomic_t value;
+};
+
+static DEFINE_HASHTABLE(package_to_appid, 8);
+static DEFINE_HASHTABLE(package_to_userid, 8);
+static DEFINE_HASHTABLE(ext_to_groupid, 8);
+
+
+static struct kmem_cache *hashtable_entry_cachep;
+
+static unsigned int full_name_case_hash(const void *salt, const unsigned char *name, unsigned int len)
+{
+ unsigned long hash = init_name_hash(salt);
+
+ while (len--)
+ hash = partial_name_hash(tolower(*name++), hash);
+ return end_name_hash(hash);
+}
+
+static inline void qstr_init(struct qstr *q, const char *name)
+{
+ q->name = name;
+ q->len = strlen(q->name);
+ q->hash = full_name_case_hash(0, q->name, q->len);
+}
+
+static inline int qstr_copy(const struct qstr *src, struct qstr *dest)
+{
+ dest->name = kstrdup(src->name, GFP_KERNEL);
+ dest->hash_len = src->hash_len;
+ return !!dest->name;
+}
+
+
+static appid_t __get_appid(const struct qstr *key)
+{
+ struct hashtable_entry *hash_cur;
+ unsigned int hash = key->hash;
+ appid_t ret_id;
+
+ rcu_read_lock();
+ hash_for_each_possible_rcu(package_to_appid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
+ ret_id = atomic_read(&hash_cur->value);
+ rcu_read_unlock();
+ return ret_id;
+ }
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+appid_t get_appid(const char *key)
+{
+ struct qstr q;
+
+ qstr_init(&q, key);
+ return __get_appid(&q);
+}
+
+static appid_t __get_ext_gid(const struct qstr *key)
+{
+ struct hashtable_entry *hash_cur;
+ unsigned int hash = key->hash;
+ appid_t ret_id;
+
+ rcu_read_lock();
+ hash_for_each_possible_rcu(ext_to_groupid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
+ ret_id = atomic_read(&hash_cur->value);
+ rcu_read_unlock();
+ return ret_id;
+ }
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+appid_t get_ext_gid(const char *key)
+{
+ struct qstr q;
+
+ qstr_init(&q, key);
+ return __get_ext_gid(&q);
+}
+
+static appid_t __is_excluded(const struct qstr *app_name, userid_t user)
+{
+ struct hashtable_entry *hash_cur;
+ unsigned int hash = app_name->hash;
+
+ rcu_read_lock();
+ hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
+ if (atomic_read(&hash_cur->value) == user &&
+ qstr_case_eq(app_name, &hash_cur->key)) {
+ rcu_read_unlock();
+ return 1;
+ }
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+appid_t is_excluded(const char *key, userid_t user)
+{
+ struct qstr q;
+ qstr_init(&q, key);
+ return __is_excluded(&q, user);
+}
+
+/* Kernel has already enforced everything we returned through
+ * derive_permissions_locked(), so this is used to lock down access
+ * even further, such as enforcing that apps hold sdcard_rw.
+ */
+int check_caller_access_to_name(struct inode *parent_node, const struct qstr *name)
+{
+ struct qstr q_autorun = QSTR_LITERAL("autorun.inf");
+ struct qstr q__android_secure = QSTR_LITERAL(".android_secure");
+ struct qstr q_android_secure = QSTR_LITERAL("android_secure");
+
+ /* Always block security-sensitive files at root */
+ if (parent_node && SDCARDFS_I(parent_node)->data->perm == PERM_ROOT) {
+ if (qstr_case_eq(name, &q_autorun)
+ || qstr_case_eq(name, &q__android_secure)
+ || qstr_case_eq(name, &q_android_secure)) {
+ return 0;
+ }
+ }
+
+ /* Root always has access; access for any other UIDs should always
+ * be controlled through packages.list.
+ */
+ if (from_kuid(&init_user_ns, current_fsuid()) == 0)
+ return 1;
+
+ /* No extra permissions to enforce */
+ return 1;
+}
+
+static struct hashtable_entry *alloc_hashtable_entry(const struct qstr *key,
+ appid_t value)
+{
+ struct hashtable_entry *ret = kmem_cache_alloc(hashtable_entry_cachep,
+ GFP_KERNEL);
+ if (!ret)
+ return NULL;
+ INIT_HLIST_NODE(&ret->dlist);
+ INIT_HLIST_NODE(&ret->hlist);
+
+ if (!qstr_copy(key, &ret->key)) {
+ kmem_cache_free(hashtable_entry_cachep, ret);
+ return NULL;
+ }
+
+ atomic_set(&ret->value, value);
+ return ret;
+}
+
+static int insert_packagelist_appid_entry_locked(const struct qstr *key, appid_t value)
+{
+ struct hashtable_entry *hash_cur;
+ struct hashtable_entry *new_entry;
+ unsigned int hash = key->hash;
+
+ hash_for_each_possible_rcu(package_to_appid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
+ atomic_set(&hash_cur->value, value);
+ return 0;
+ }
+ }
+ new_entry = alloc_hashtable_entry(key, value);
+ if (!new_entry)
+ return -ENOMEM;
+ hash_add_rcu(package_to_appid, &new_entry->hlist, hash);
+ return 0;
+}
+
+static int insert_ext_gid_entry_locked(const struct qstr *key, appid_t value)
+{
+ struct hashtable_entry *hash_cur;
+ struct hashtable_entry *new_entry;
+ unsigned int hash = key->hash;
+
+ /* An extension can only belong to one gid */
+ hash_for_each_possible_rcu(ext_to_groupid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key))
+ return -EINVAL;
+ }
+ new_entry = alloc_hashtable_entry(key, value);
+ if (!new_entry)
+ return -ENOMEM;
+ hash_add_rcu(ext_to_groupid, &new_entry->hlist, hash);
+ return 0;
+}
+
+static int insert_userid_exclude_entry_locked(const struct qstr *key, userid_t value)
+{
+ struct hashtable_entry *hash_cur;
+ struct hashtable_entry *new_entry;
+ unsigned int hash = key->hash;
+
+ /* Only insert if not already present */
+ hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
+ if (atomic_read(&hash_cur->value) == value &&
+ qstr_case_eq(key, &hash_cur->key))
+ return 0;
+ }
+ new_entry = alloc_hashtable_entry(key, value);
+ if (!new_entry)
+ return -ENOMEM;
+ hash_add_rcu(package_to_userid, &new_entry->hlist, hash);
+ return 0;
+}
+
+static void fixup_all_perms_name(const struct qstr *key)
+{
+ struct sdcardfs_sb_info *sbinfo;
+ struct limit_search limit = {
+ .flags = BY_NAME,
+ .name = QSTR_INIT(key->name, key->len),
+ };
+ list_for_each_entry(sbinfo, &sdcardfs_super_list, list) {
+ if (sbinfo_has_sdcard_magic(sbinfo))
+ fixup_perms_recursive(sbinfo->sb->s_root, &limit);
+ }
+}
+
+static void fixup_all_perms_name_userid(const struct qstr *key, userid_t userid)
+{
+ struct sdcardfs_sb_info *sbinfo;
+ struct limit_search limit = {
+ .flags = BY_NAME | BY_USERID,
+ .name = QSTR_INIT(key->name, key->len),
+ .userid = userid,
+ };
+ list_for_each_entry(sbinfo, &sdcardfs_super_list, list) {
+ if (sbinfo_has_sdcard_magic(sbinfo))
+ fixup_perms_recursive(sbinfo->sb->s_root, &limit);
+ }
+}
+
+static void fixup_all_perms_userid(userid_t userid)
+{
+ struct sdcardfs_sb_info *sbinfo;
+ struct limit_search limit = {
+ .flags = BY_USERID,
+ .userid = userid,
+ };
+ list_for_each_entry(sbinfo, &sdcardfs_super_list, list) {
+ if (sbinfo_has_sdcard_magic(sbinfo))
+ fixup_perms_recursive(sbinfo->sb->s_root, &limit);
+ }
+}
+
+static int insert_packagelist_entry(const struct qstr *key, appid_t value)
+{
+ int err;
+
+ mutex_lock(&sdcardfs_super_list_lock);
+ err = insert_packagelist_appid_entry_locked(key, value);
+ if (!err)
+ fixup_all_perms_name(key);
+ mutex_unlock(&sdcardfs_super_list_lock);
+
+ return err;
+}
+
+static int insert_ext_gid_entry(const struct qstr *key, appid_t value)
+{
+ int err;
+
+ mutex_lock(&sdcardfs_super_list_lock);
+ err = insert_ext_gid_entry_locked(key, value);
+ mutex_unlock(&sdcardfs_super_list_lock);
+
+ return err;
+}
+
+static int insert_userid_exclude_entry(const struct qstr *key, userid_t value)
+{
+ int err;
+
+ mutex_lock(&sdcardfs_super_list_lock);
+ err = insert_userid_exclude_entry_locked(key, value);
+ if (!err)
+ fixup_all_perms_name_userid(key, value);
+ mutex_unlock(&sdcardfs_super_list_lock);
+
+ return err;
+}
+
+static void free_hashtable_entry(struct hashtable_entry *entry)
+{
+ kfree(entry->key.name);
+ kmem_cache_free(hashtable_entry_cachep, entry);
+}
+
+static void remove_packagelist_entry_locked(const struct qstr *key)
+{
+ struct hashtable_entry *hash_cur;
+ unsigned int hash = key->hash;
+ struct hlist_node *h_t;
+ HLIST_HEAD(free_list);
+
+ hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
+ hash_del_rcu(&hash_cur->hlist);
+ hlist_add_head(&hash_cur->dlist, &free_list);
+ }
+ }
+ hash_for_each_possible_rcu(package_to_appid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
+ hash_del_rcu(&hash_cur->hlist);
+ hlist_add_head(&hash_cur->dlist, &free_list);
+ break;
+ }
+ }
+ synchronize_rcu();
+ hlist_for_each_entry_safe(hash_cur, h_t, &free_list, dlist)
+ free_hashtable_entry(hash_cur);
+}
+
+static void remove_packagelist_entry(const struct qstr *key)
+{
+ mutex_lock(&sdcardfs_super_list_lock);
+ remove_packagelist_entry_locked(key);
+ fixup_all_perms_name(key);
+ mutex_unlock(&sdcardfs_super_list_lock);
+}
+
+static void remove_ext_gid_entry_locked(const struct qstr *key, gid_t group)
+{
+ struct hashtable_entry *hash_cur;
+ unsigned int hash = key->hash;
+
+ hash_for_each_possible_rcu(ext_to_groupid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key) && atomic_read(&hash_cur->value) == group) {
+ hash_del_rcu(&hash_cur->hlist);
+ synchronize_rcu();
+ free_hashtable_entry(hash_cur);
+ break;
+ }
+ }
+}
+
+static void remove_ext_gid_entry(const struct qstr *key, gid_t group)
+{
+ mutex_lock(&sdcardfs_super_list_lock);
+ remove_ext_gid_entry_locked(key, group);
+ mutex_unlock(&sdcardfs_super_list_lock);
+}
+
+static void remove_userid_all_entry_locked(userid_t userid)
+{
+ struct hashtable_entry *hash_cur;
+ struct hlist_node *h_t;
+ HLIST_HEAD(free_list);
+ int i;
+
+ hash_for_each_rcu(package_to_userid, i, hash_cur, hlist) {
+ if (atomic_read(&hash_cur->value) == userid) {
+ hash_del_rcu(&hash_cur->hlist);
+ hlist_add_head(&hash_cur->dlist, &free_list);
+ }
+ }
+ synchronize_rcu();
+ hlist_for_each_entry_safe(hash_cur, h_t, &free_list, dlist) {
+ free_hashtable_entry(hash_cur);
+ }
+}
+
+static void remove_userid_all_entry(userid_t userid)
+{
+ mutex_lock(&sdcardfs_super_list_lock);
+ remove_userid_all_entry_locked(userid);
+ fixup_all_perms_userid(userid);
+ mutex_unlock(&sdcardfs_super_list_lock);
+}
+
+static void remove_userid_exclude_entry_locked(const struct qstr *key, userid_t userid)
+{
+ struct hashtable_entry *hash_cur;
+ unsigned int hash = key->hash;
+
+ hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(key, &hash_cur->key) &&
+ atomic_read(&hash_cur->value) == userid) {
+ hash_del_rcu(&hash_cur->hlist);
+ synchronize_rcu();
+ free_hashtable_entry(hash_cur);
+ break;
+ }
+ }
+}
+
+static void remove_userid_exclude_entry(const struct qstr *key, userid_t userid)
+{
+ mutex_lock(&sdcardfs_super_list_lock);
+ remove_userid_exclude_entry_locked(key, userid);
+ fixup_all_perms_name_userid(key, userid);
+ mutex_unlock(&sdcardfs_super_list_lock);
+}
+
+static void packagelist_destroy(void)
+{
+ struct hashtable_entry *hash_cur;
+ struct hlist_node *h_t;
+ HLIST_HEAD(free_list);
+ int i;
+
+ mutex_lock(&sdcardfs_super_list_lock);
+ hash_for_each_rcu(package_to_appid, i, hash_cur, hlist) {
+ hash_del_rcu(&hash_cur->hlist);
+ hlist_add_head(&hash_cur->dlist, &free_list);
+ }
+ hash_for_each_rcu(package_to_userid, i, hash_cur, hlist) {
+ hash_del_rcu(&hash_cur->hlist);
+ hlist_add_head(&hash_cur->dlist, &free_list);
+ }
+ synchronize_rcu();
+ hlist_for_each_entry_safe(hash_cur, h_t, &free_list, dlist)
+ free_hashtable_entry(hash_cur);
+ mutex_unlock(&sdcardfs_super_list_lock);
+ pr_info("sdcardfs: destroyed packagelist pkgld\n");
+}
+
+#define SDCARDFS_CONFIGFS_ATTR(_pfx, _name) \
+static struct configfs_attribute _pfx##attr_##_name = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IRUGO | S_IWUGO, \
+ .ca_owner = THIS_MODULE, \
+ .show = _pfx##_name##_show, \
+ .store = _pfx##_name##_store, \
+}
+
+#define SDCARDFS_CONFIGFS_ATTR_RO(_pfx, _name) \
+static struct configfs_attribute _pfx##attr_##_name = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IRUGO, \
+ .ca_owner = THIS_MODULE, \
+ .show = _pfx##_name##_show, \
+}
+
+#define SDCARDFS_CONFIGFS_ATTR_WO(_pfx, _name) \
+static struct configfs_attribute _pfx##attr_##_name = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IWUGO, \
+ .ca_owner = THIS_MODULE, \
+ .store = _pfx##_name##_store, \
+}
+
+struct package_details {
+ struct config_item item;
+ struct qstr name;
+};
+
+static inline struct package_details *to_package_details(struct config_item *item)
+{
+ return item ? container_of(item, struct package_details, item) : NULL;
+}
+
+static ssize_t package_details_appid_show(struct config_item *item, char *page)
+{
+ return scnprintf(page, PAGE_SIZE, "%u\n", __get_appid(&to_package_details(item)->name));
+}
+
+static ssize_t package_details_appid_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ unsigned int tmp;
+ int ret;
+
+ ret = kstrtouint(page, 10, &tmp);
+ if (ret)
+ return ret;
+
+ ret = insert_packagelist_entry(&to_package_details(item)->name, tmp);
+
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static ssize_t package_details_excluded_userids_show(struct config_item *item,
+ char *page)
+{
+ struct package_details *package_details = to_package_details(item);
+ struct hashtable_entry *hash_cur;
+ unsigned int hash = package_details->name.hash;
+ int count = 0;
+
+ rcu_read_lock();
+ hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
+ if (qstr_case_eq(&package_details->name, &hash_cur->key))
+ count += scnprintf(page + count, PAGE_SIZE - count,
+ "%d ", atomic_read(&hash_cur->value));
+ }
+ rcu_read_unlock();
+ if (count)
+ count--;
+ count += scnprintf(page + count, PAGE_SIZE - count, "\n");
+ return count;
+}
+
+static ssize_t package_details_excluded_userids_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ unsigned int tmp;
+ int ret;
+
+ ret = kstrtouint(page, 10, &tmp);
+ if (ret)
+ return ret;
+
+ ret = insert_userid_exclude_entry(&to_package_details(item)->name, tmp);
+
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static ssize_t package_details_clear_userid_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ unsigned int tmp;
+ int ret;
+
+ ret = kstrtouint(page, 10, &tmp);
+ if (ret)
+ return ret;
+ remove_userid_exclude_entry(&to_package_details(item)->name, tmp);
+ return count;
+}
+
+static void package_details_release(struct config_item *item)
+{
+ struct package_details *package_details = to_package_details(item);
+
+ pr_info("sdcardfs: removing %s\n", package_details->name.name);
+ remove_packagelist_entry(&package_details->name);
+ kfree(package_details->name.name);
+ kfree(package_details);
+}
+
+SDCARDFS_CONFIGFS_ATTR(package_details_, appid);
+SDCARDFS_CONFIGFS_ATTR(package_details_, excluded_userids);
+SDCARDFS_CONFIGFS_ATTR_WO(package_details_, clear_userid);
+
+static struct configfs_attribute *package_details_attrs[] = {
+ &package_details_attr_appid,
+ &package_details_attr_excluded_userids,
+ &package_details_attr_clear_userid,
+ NULL,
+};
+
+static struct configfs_item_operations package_details_item_ops = {
+ .release = package_details_release,
+};
+
+static struct config_item_type package_appid_type = {
+ .ct_item_ops = &package_details_item_ops,
+ .ct_attrs = package_details_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+struct extensions_value {
+ struct config_group group;
+ unsigned int num;
+};
+
+struct extension_details {
+ struct config_item item;
+ struct qstr name;
+ unsigned int num;
+};
+
+static inline struct extensions_value *to_extensions_value(struct config_item *item)
+{
+ return item ? container_of(to_config_group(item), struct extensions_value, group) : NULL;
+}
+
+static inline struct extension_details *to_extension_details(struct config_item *item)
+{
+ return item ? container_of(item, struct extension_details, item) : NULL;
+}
+
+static void extension_details_release(struct config_item *item)
+{
+ struct extension_details *extension_details = to_extension_details(item);
+
+ pr_info("sdcardfs: No longer mapping %s files to gid %d\n",
+ extension_details->name.name, extension_details->num);
+ remove_ext_gid_entry(&extension_details->name, extension_details->num);
+ kfree(extension_details->name.name);
+ kfree(extension_details);
+}
+
+static struct configfs_item_operations extension_details_item_ops = {
+ .release = extension_details_release,
+};
+
+static struct config_item_type extension_details_type = {
+ .ct_item_ops = &extension_details_item_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_item *extension_details_make_item(struct config_group *group, const char *name)
+{
+ struct extensions_value *extensions_value = to_extensions_value(&group->cg_item);
+ struct extension_details *extension_details = kzalloc(sizeof(struct extension_details), GFP_KERNEL);
+ const char *tmp;
+ int ret;
+
+ if (!extension_details)
+ return ERR_PTR(-ENOMEM);
+
+ tmp = kstrdup(name, GFP_KERNEL);
+ if (!tmp) {
+ kfree(extension_details);
+ return ERR_PTR(-ENOMEM);
+ }
+ qstr_init(&extension_details->name, tmp);
+ extension_details->num = extensions_value->num;
+ ret = insert_ext_gid_entry(&extension_details->name, extensions_value->num);
+
+ if (ret) {
+ kfree(extension_details->name.name);
+ kfree(extension_details);
+ return ERR_PTR(ret);
+ }
+ config_item_init_type_name(&extension_details->item, name, &extension_details_type);
+
+ return &extension_details->item;
+}
+
+static struct configfs_group_operations extensions_value_group_ops = {
+ .make_item = extension_details_make_item,
+};
+
+static struct config_item_type extensions_name_type = {
+ .ct_group_ops = &extensions_value_group_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_group *extensions_make_group(struct config_group *group, const char *name)
+{
+ struct extensions_value *extensions_value;
+ unsigned int tmp;
+ int ret;
+
+ extensions_value = kzalloc(sizeof(struct extensions_value), GFP_KERNEL);
+ if (!extensions_value)
+ return ERR_PTR(-ENOMEM);
+ ret = kstrtouint(name, 10, &tmp);
+ if (ret) {
+ kfree(extensions_value);
+ return ERR_PTR(ret);
+ }
+
+ extensions_value->num = tmp;
+ config_group_init_type_name(&extensions_value->group, name,
+ &extensions_name_type);
+ return &extensions_value->group;
+}
+
+static void extensions_drop_group(struct config_group *group, struct config_item *item)
+{
+ struct extensions_value *value = to_extensions_value(item);
+
+ pr_info("sdcardfs: No longer mapping any files to gid %d\n", value->num);
+ kfree(value);
+}
+
+static struct configfs_group_operations extensions_group_ops = {
+ .make_group = extensions_make_group,
+ .drop_item = extensions_drop_group,
+};
+
+static struct config_item_type extensions_type = {
+ .ct_group_ops = &extensions_group_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+struct config_group extension_group = {
+ .cg_item = {
+ .ci_namebuf = "extensions",
+ .ci_type = &extensions_type,
+ },
+};
+
+static struct config_item *packages_make_item(struct config_group *group, const char *name)
+{
+ struct package_details *package_details;
+ const char *tmp;
+
+ package_details = kzalloc(sizeof(struct package_details), GFP_KERNEL);
+ if (!package_details)
+ return ERR_PTR(-ENOMEM);
+ tmp = kstrdup(name, GFP_KERNEL);
+ if (!tmp) {
+ kfree(package_details);
+ return ERR_PTR(-ENOMEM);
+ }
+ qstr_init(&package_details->name, tmp);
+ config_item_init_type_name(&package_details->item, name,
+ &package_appid_type);
+
+ return &package_details->item;
+}
+
+static ssize_t packages_list_show(struct config_item *item, char *page)
+{
+ struct hashtable_entry *hash_cur_app;
+ struct hashtable_entry *hash_cur_user;
+ int i;
+ int count = 0, written = 0;
+ const char errormsg[] = "<truncated>\n";
+ unsigned int hash;
+
+ rcu_read_lock();
+ hash_for_each_rcu(package_to_appid, i, hash_cur_app, hlist) {
+ written = scnprintf(page + count, PAGE_SIZE - sizeof(errormsg) - count, "%s %d\n",
+ hash_cur_app->key.name, atomic_read(&hash_cur_app->value));
+ hash = hash_cur_app->key.hash;
+ hash_for_each_possible_rcu(package_to_userid, hash_cur_user, hlist, hash) {
+ if (qstr_case_eq(&hash_cur_app->key, &hash_cur_user->key)) {
+ written += scnprintf(page + count + written - 1,
+ PAGE_SIZE - sizeof(errormsg) - count - written + 1,
+ " %d\n", atomic_read(&hash_cur_user->value)) - 1;
+ }
+ }
+ if (count + written == PAGE_SIZE - sizeof(errormsg) - 1) {
+ count += scnprintf(page + count, PAGE_SIZE - count, errormsg);
+ break;
+ }
+ count += written;
+ }
+ rcu_read_unlock();
+
+ return count;
+}
+
+static ssize_t packages_remove_userid_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ unsigned int tmp;
+ int ret;
+
+ ret = kstrtouint(page, 10, &tmp);
+ if (ret)
+ return ret;
+ remove_userid_all_entry(tmp);
+ return count;
+}
+
+static struct configfs_attribute packages_attr_packages_gid_list = {
+ .ca_name = "packages_gid.list",
+ .ca_mode = S_IRUGO,
+ .ca_owner = THIS_MODULE,
+ .show = packages_list_show,
+};
+
+SDCARDFS_CONFIGFS_ATTR_WO(packages_, remove_userid);
+
+static struct configfs_attribute *packages_attrs[] = {
+ &packages_attr_packages_gid_list,
+ &packages_attr_remove_userid,
+ NULL,
+};
+
+/*
+ * Note that, since no extra work is required on ->drop_item(),
+ * no ->drop_item() is provided.
+ */
+static struct configfs_group_operations packages_group_ops = {
+ .make_item = packages_make_item,
+};
+
+static struct config_item_type packages_type = {
+ .ct_group_ops = &packages_group_ops,
+ .ct_attrs = packages_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+struct config_group *sd_default_groups[] = {
+ &extension_group,
+ NULL,
+};
+
+static struct configfs_subsystem sdcardfs_packages = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "sdcardfs",
+ .ci_type = &packages_type,
+ },
+ },
+};
+
+static int configfs_sdcardfs_init(void)
+{
+ int ret, i;
+ struct configfs_subsystem *subsys = &sdcardfs_packages;
+
+ config_group_init(&subsys->su_group);
+ for (i = 0; sd_default_groups[i]; i++) {
+ config_group_init(sd_default_groups[i]);
+ configfs_add_default_group(sd_default_groups[i], &subsys->su_group);
+ }
+ mutex_init(&subsys->su_mutex);
+ ret = configfs_register_subsystem(subsys);
+ if (ret) {
+ pr_err("Error %d while registering subsystem %s\n",
+ ret,
+ subsys->su_group.cg_item.ci_namebuf);
+ }
+ return ret;
+}
+
+static void configfs_sdcardfs_exit(void)
+{
+ configfs_unregister_subsystem(&sdcardfs_packages);
+}
+
+int packagelist_init(void)
+{
+ hashtable_entry_cachep =
+ kmem_cache_create("packagelist_hashtable_entry",
+ sizeof(struct hashtable_entry), 0, 0, NULL);
+ if (!hashtable_entry_cachep) {
+ pr_err("sdcardfs: failed creating pkgl_hashtable entry slab cache\n");
+ return -ENOMEM;
+ }
+
+ configfs_sdcardfs_init();
+ return 0;
+}
+
+void packagelist_exit(void)
+{
+ configfs_sdcardfs_exit();
+ packagelist_destroy();
+ kmem_cache_destroy(hashtable_entry_cachep);
+}
diff --git a/fs/sdcardfs/sdcardfs.h b/fs/sdcardfs/sdcardfs.h
new file mode 100644
index 0000000..9ccf62c
--- /dev/null
+++ b/fs/sdcardfs/sdcardfs.h
@@ -0,0 +1,655 @@
+/*
+ * fs/sdcardfs/sdcardfs.h
+ *
+ * The sdcardfs v2.0
+ * This file system replaces the sdcard daemon on Android
+ * On version 2.0, some of the daemon functions have been ported
+ * to support the multi-user concepts of Android 4.4
+ *
+ * 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.
+ */
+
+#ifndef _SDCARDFS_H_
+#define _SDCARDFS_H_
+
+#include <linux/dcache.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/aio.h>
+#include <linux/kref.h>
+#include <linux/mm.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/seq_file.h>
+#include <linux/statfs.h>
+#include <linux/fs_stack.h>
+#include <linux/magic.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/security.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/iversion.h>
+#include "multiuser.h"
+
+/* the file system name */
+#define SDCARDFS_NAME "sdcardfs"
+
+/* sdcardfs root inode number */
+#define SDCARDFS_ROOT_INO 1
+
+/* useful for tracking code reachability */
+#define UDBG pr_default("DBG:%s:%s:%d\n", __FILE__, __func__, __LINE__)
+
+#define SDCARDFS_DIRENT_SIZE 256
+
+/* temporary static uid settings for development */
+#define AID_ROOT 0 /* uid for accessing /mnt/sdcard & extSdcard */
+#define AID_MEDIA_RW 1023 /* internal media storage write access */
+
+#define AID_SDCARD_RW 1015 /* external storage write access */
+#define AID_SDCARD_R 1028 /* external storage read access */
+#define AID_SDCARD_PICS 1033 /* external storage photos access */
+#define AID_SDCARD_AV 1034 /* external storage audio/video access */
+#define AID_SDCARD_ALL 1035 /* access all users external storage */
+#define AID_MEDIA_OBB 1059 /* obb files */
+
+#define AID_SDCARD_IMAGE 1057
+
+#define AID_PACKAGE_INFO 1027
+
+
+/*
+ * Permissions are handled by our permission function.
+ * We don't want anyone who happens to look at our inode value to prematurely
+ * block access, so store more permissive values. These are probably never
+ * used.
+ */
+#define fixup_tmp_permissions(x) \
+ do { \
+ (x)->i_uid = make_kuid(&init_user_ns, \
+ SDCARDFS_I(x)->data->d_uid); \
+ (x)->i_gid = make_kgid(&init_user_ns, AID_SDCARD_RW); \
+ (x)->i_mode = ((x)->i_mode & S_IFMT) | 0775;\
+ } while (0)
+
+/* Android 5.0 support */
+
+/* Permission mode for a specific node. Controls how file permissions
+ * are derived for children nodes.
+ */
+typedef enum {
+ /* Nothing special; this node should just inherit from its parent. */
+ PERM_INHERIT,
+ /* This node is one level above a normal root; used for legacy layouts
+ * which use the first level to represent user_id.
+ */
+ PERM_PRE_ROOT,
+ /* This node is "/" */
+ PERM_ROOT,
+ /* This node is "/Android" */
+ PERM_ANDROID,
+ /* This node is "/Android/data" */
+ PERM_ANDROID_DATA,
+ /* This node is "/Android/obb" */
+ PERM_ANDROID_OBB,
+ /* This node is "/Android/media" */
+ PERM_ANDROID_MEDIA,
+ /* This node is "/Android/[data|media|obb]/[package]" */
+ PERM_ANDROID_PACKAGE,
+ /* This node is "/Android/[data|media|obb]/[package]/cache" */
+ PERM_ANDROID_PACKAGE_CACHE,
+} perm_t;
+
+struct sdcardfs_sb_info;
+struct sdcardfs_mount_options;
+struct sdcardfs_inode_info;
+struct sdcardfs_inode_data;
+
+/* Do not directly use this function. Use OVERRIDE_CRED() instead. */
+const struct cred *override_fsids(struct sdcardfs_sb_info *sbi,
+ struct sdcardfs_inode_data *data);
+/* Do not directly use this function, use REVERT_CRED() instead. */
+void revert_fsids(const struct cred *old_cred);
+
+/* operations vectors defined in specific files */
+extern const struct file_operations sdcardfs_main_fops;
+extern const struct file_operations sdcardfs_dir_fops;
+extern const struct inode_operations sdcardfs_main_iops;
+extern const struct inode_operations sdcardfs_dir_iops;
+extern const struct inode_operations sdcardfs_symlink_iops;
+extern const struct super_operations sdcardfs_sops;
+extern const struct dentry_operations sdcardfs_ci_dops;
+extern const struct address_space_operations sdcardfs_aops, sdcardfs_dummy_aops;
+extern const struct vm_operations_struct sdcardfs_vm_ops;
+
+extern int sdcardfs_init_inode_cache(void);
+extern void sdcardfs_destroy_inode_cache(void);
+extern int sdcardfs_init_dentry_cache(void);
+extern void sdcardfs_destroy_dentry_cache(void);
+extern int new_dentry_private_data(struct dentry *dentry);
+extern void free_dentry_private_data(struct dentry *dentry);
+extern struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags);
+extern struct inode *sdcardfs_iget(struct super_block *sb,
+ struct inode *lower_inode, userid_t id);
+extern int sdcardfs_interpose(struct dentry *dentry, struct super_block *sb,
+ struct path *lower_path, userid_t id);
+
+/* file private data */
+struct sdcardfs_file_info {
+ struct file *lower_file;
+ const struct vm_operations_struct *lower_vm_ops;
+};
+
+struct sdcardfs_inode_data {
+ struct kref refcount;
+ bool abandoned;
+
+ perm_t perm;
+ userid_t userid;
+ uid_t d_uid;
+ bool under_android;
+ bool under_cache;
+ bool under_obb;
+};
+
+/* sdcardfs inode data in memory */
+struct sdcardfs_inode_info {
+ struct inode *lower_inode;
+ /* state derived based on current position in hierarchy */
+ struct sdcardfs_inode_data *data;
+
+ /* top folder for ownership */
+ spinlock_t top_lock;
+ struct sdcardfs_inode_data *top_data;
+
+ struct inode vfs_inode;
+};
+
+
+/* sdcardfs dentry data in memory */
+struct sdcardfs_dentry_info {
+ spinlock_t lock; /* protects lower_path */
+ struct path lower_path;
+ struct path orig_path;
+};
+
+struct sdcardfs_mount_options {
+ uid_t fs_low_uid;
+ gid_t fs_low_gid;
+ userid_t fs_user_id;
+ bool multiuser;
+ bool gid_derivation;
+ bool default_normal;
+ bool unshared_obb;
+ unsigned int reserved_mb;
+ bool nocache;
+};
+
+struct sdcardfs_vfsmount_options {
+ gid_t gid;
+ mode_t mask;
+};
+
+extern int parse_options_remount(struct super_block *sb, char *options, int silent,
+ struct sdcardfs_vfsmount_options *vfsopts);
+
+/* sdcardfs super-block data in memory */
+struct sdcardfs_sb_info {
+ struct super_block *sb;
+ struct super_block *lower_sb;
+ /* derived perm policy : some of options have been added
+ * to sdcardfs_mount_options (Android 4.4 support)
+ */
+ struct sdcardfs_mount_options options;
+ spinlock_t lock; /* protects obbpath */
+ char *obbpath_s;
+ struct path obbpath;
+ void *pkgl_id;
+ struct list_head list;
+};
+
+/*
+ * inode to private data
+ *
+ * Since we use containers and the struct inode is _inside_ the
+ * sdcardfs_inode_info structure, SDCARDFS_I will always (given a non-NULL
+ * inode pointer), return a valid non-NULL pointer.
+ */
+static inline struct sdcardfs_inode_info *SDCARDFS_I(const struct inode *inode)
+{
+ return container_of(inode, struct sdcardfs_inode_info, vfs_inode);
+}
+
+/* dentry to private data */
+#define SDCARDFS_D(dent) ((struct sdcardfs_dentry_info *)(dent)->d_fsdata)
+
+/* superblock to private data */
+#define SDCARDFS_SB(super) ((struct sdcardfs_sb_info *)(super)->s_fs_info)
+
+/* file to private Data */
+#define SDCARDFS_F(file) ((struct sdcardfs_file_info *)((file)->private_data))
+
+/* file to lower file */
+static inline struct file *sdcardfs_lower_file(const struct file *f)
+{
+ return SDCARDFS_F(f)->lower_file;
+}
+
+static inline void sdcardfs_set_lower_file(struct file *f, struct file *val)
+{
+ SDCARDFS_F(f)->lower_file = val;
+}
+
+/* inode to lower inode. */
+static inline struct inode *sdcardfs_lower_inode(const struct inode *i)
+{
+ return SDCARDFS_I(i)->lower_inode;
+}
+
+static inline void sdcardfs_set_lower_inode(struct inode *i, struct inode *val)
+{
+ SDCARDFS_I(i)->lower_inode = val;
+}
+
+/* superblock to lower superblock */
+static inline struct super_block *sdcardfs_lower_super(
+ const struct super_block *sb)
+{
+ return SDCARDFS_SB(sb)->lower_sb;
+}
+
+static inline void sdcardfs_set_lower_super(struct super_block *sb,
+ struct super_block *val)
+{
+ SDCARDFS_SB(sb)->lower_sb = val;
+}
+
+/* path based (dentry/mnt) macros */
+static inline void pathcpy(struct path *dst, const struct path *src)
+{
+ dst->dentry = src->dentry;
+ dst->mnt = src->mnt;
+}
+
+/* sdcardfs_get_pname functions calls path_get()
+ * therefore, the caller must call "proper" path_put functions
+ */
+#define SDCARDFS_DENT_FUNC(pname) \
+static inline void sdcardfs_get_##pname(const struct dentry *dent, \
+ struct path *pname) \
+{ \
+ spin_lock(&SDCARDFS_D(dent)->lock); \
+ pathcpy(pname, &SDCARDFS_D(dent)->pname); \
+ path_get(pname); \
+ spin_unlock(&SDCARDFS_D(dent)->lock); \
+ return; \
+} \
+static inline void sdcardfs_put_##pname(const struct dentry *dent, \
+ struct path *pname) \
+{ \
+ path_put(pname); \
+ return; \
+} \
+static inline void sdcardfs_set_##pname(const struct dentry *dent, \
+ struct path *pname) \
+{ \
+ spin_lock(&SDCARDFS_D(dent)->lock); \
+ pathcpy(&SDCARDFS_D(dent)->pname, pname); \
+ spin_unlock(&SDCARDFS_D(dent)->lock); \
+ return; \
+} \
+static inline void sdcardfs_reset_##pname(const struct dentry *dent) \
+{ \
+ spin_lock(&SDCARDFS_D(dent)->lock); \
+ SDCARDFS_D(dent)->pname.dentry = NULL; \
+ SDCARDFS_D(dent)->pname.mnt = NULL; \
+ spin_unlock(&SDCARDFS_D(dent)->lock); \
+ return; \
+} \
+static inline void sdcardfs_put_reset_##pname(const struct dentry *dent) \
+{ \
+ struct path pname; \
+ spin_lock(&SDCARDFS_D(dent)->lock); \
+ if (SDCARDFS_D(dent)->pname.dentry) { \
+ pathcpy(&pname, &SDCARDFS_D(dent)->pname); \
+ SDCARDFS_D(dent)->pname.dentry = NULL; \
+ SDCARDFS_D(dent)->pname.mnt = NULL; \
+ spin_unlock(&SDCARDFS_D(dent)->lock); \
+ path_put(&pname); \
+ } else \
+ spin_unlock(&SDCARDFS_D(dent)->lock); \
+ return; \
+}
+
+SDCARDFS_DENT_FUNC(lower_path)
+SDCARDFS_DENT_FUNC(orig_path)
+
+static inline bool sbinfo_has_sdcard_magic(struct sdcardfs_sb_info *sbinfo)
+{
+ return sbinfo && sbinfo->sb
+ && sbinfo->sb->s_magic == SDCARDFS_SUPER_MAGIC;
+}
+
+static inline struct sdcardfs_inode_data *data_get(
+ struct sdcardfs_inode_data *data)
+{
+ if (data)
+ kref_get(&data->refcount);
+ return data;
+}
+
+static inline struct sdcardfs_inode_data *top_data_get(
+ struct sdcardfs_inode_info *info)
+{
+ struct sdcardfs_inode_data *top_data;
+
+ spin_lock(&info->top_lock);
+ top_data = data_get(info->top_data);
+ spin_unlock(&info->top_lock);
+ return top_data;
+}
+
+extern void data_release(struct kref *ref);
+
+static inline void data_put(struct sdcardfs_inode_data *data)
+{
+ kref_put(&data->refcount, data_release);
+}
+
+static inline void release_own_data(struct sdcardfs_inode_info *info)
+{
+ /*
+ * This happens exactly once per inode. At this point, the inode that
+ * originally held this data is about to be freed, and all references
+ * to it are held as a top value, and will likely be released soon.
+ */
+ info->data->abandoned = true;
+ data_put(info->data);
+}
+
+static inline void set_top(struct sdcardfs_inode_info *info,
+ struct sdcardfs_inode_info *top_owner)
+{
+ struct sdcardfs_inode_data *old_top;
+ struct sdcardfs_inode_data *new_top = NULL;
+
+ if (top_owner)
+ new_top = top_data_get(top_owner);
+
+ spin_lock(&info->top_lock);
+ old_top = info->top_data;
+ info->top_data = new_top;
+ if (old_top)
+ data_put(old_top);
+ spin_unlock(&info->top_lock);
+}
+
+static inline int get_gid(struct vfsmount *mnt,
+ struct super_block *sb,
+ struct sdcardfs_inode_data *data)
+{
+ struct sdcardfs_vfsmount_options *vfsopts = mnt->data;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(sb);
+
+ if (vfsopts->gid == AID_SDCARD_RW && !sbi->options.default_normal)
+ /* As an optimization, certain trusted system components only run
+ * as owner but operate across all users. Since we're now handing
+ * out the sdcard_rw GID only to trusted apps, we're okay relaxing
+ * the user boundary enforcement for the default view. The UIDs
+ * assigned to app directories are still multiuser aware.
+ */
+ return AID_SDCARD_RW;
+ else
+ return multiuser_get_uid(data->userid, vfsopts->gid);
+}
+
+static inline int get_mode(struct vfsmount *mnt,
+ struct sdcardfs_inode_info *info,
+ struct sdcardfs_inode_data *data)
+{
+ int owner_mode;
+ int filtered_mode;
+ struct sdcardfs_vfsmount_options *opts = mnt->data;
+ int visible_mode = 0775 & ~opts->mask;
+
+
+ if (data->perm == PERM_PRE_ROOT) {
+ /* Top of multi-user view should always be visible to ensure
+ * secondary users can traverse inside.
+ */
+ visible_mode = 0711;
+ } else if (data->under_android) {
+ /* Block "other" access to Android directories, since only apps
+ * belonging to a specific user should be in there; we still
+ * leave +x open for the default view.
+ */
+ if (opts->gid == AID_SDCARD_RW)
+ visible_mode = visible_mode & ~0006;
+ else
+ visible_mode = visible_mode & ~0007;
+ }
+ owner_mode = info->lower_inode->i_mode & 0700;
+ filtered_mode = visible_mode & (owner_mode | (owner_mode >> 3) | (owner_mode >> 6));
+ return filtered_mode;
+}
+
+static inline int has_graft_path(const struct dentry *dent)
+{
+ int ret = 0;
+
+ spin_lock(&SDCARDFS_D(dent)->lock);
+ if (SDCARDFS_D(dent)->orig_path.dentry != NULL)
+ ret = 1;
+ spin_unlock(&SDCARDFS_D(dent)->lock);
+
+ return ret;
+}
+
+static inline void sdcardfs_get_real_lower(const struct dentry *dent,
+ struct path *real_lower)
+{
+ /* in case of a local obb dentry
+ * the orig_path should be returned
+ */
+ if (has_graft_path(dent))
+ sdcardfs_get_orig_path(dent, real_lower);
+ else
+ sdcardfs_get_lower_path(dent, real_lower);
+}
+
+static inline void sdcardfs_put_real_lower(const struct dentry *dent,
+ struct path *real_lower)
+{
+ if (has_graft_path(dent))
+ sdcardfs_put_orig_path(dent, real_lower);
+ else
+ sdcardfs_put_lower_path(dent, real_lower);
+}
+
+extern struct mutex sdcardfs_super_list_lock;
+extern struct list_head sdcardfs_super_list;
+
+/* for packagelist.c */
+extern appid_t get_appid(const char *app_name);
+extern appid_t get_ext_gid(const char *app_name);
+extern appid_t is_excluded(const char *app_name, userid_t userid);
+extern int check_caller_access_to_name(struct inode *parent_node, const struct qstr *name);
+extern int packagelist_init(void);
+extern void packagelist_exit(void);
+
+/* for derived_perm.c */
+#define BY_NAME (1 << 0)
+#define BY_USERID (1 << 1)
+struct limit_search {
+ unsigned int flags;
+ struct qstr name;
+ userid_t userid;
+};
+
+extern void setup_derived_state(struct inode *inode, perm_t perm,
+ userid_t userid, uid_t uid);
+extern void get_derived_permission(struct dentry *parent, struct dentry *dentry);
+extern void get_derived_permission_new(struct dentry *parent, struct dentry *dentry, const struct qstr *name);
+extern void fixup_perms_recursive(struct dentry *dentry, struct limit_search *limit);
+
+extern void update_derived_permission_lock(struct dentry *dentry);
+void fixup_lower_ownership(struct dentry *dentry, const char *name);
+extern int need_graft_path(struct dentry *dentry);
+extern int is_base_obbpath(struct dentry *dentry);
+extern int is_obbpath_invalid(struct dentry *dentry);
+extern int setup_obb_dentry(struct dentry *dentry, struct path *lower_path);
+
+/* locking helpers */
+static inline struct dentry *lock_parent(struct dentry *dentry)
+{
+ struct dentry *dir = dget_parent(dentry);
+
+ inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
+ return dir;
+}
+
+static inline void unlock_dir(struct dentry *dir)
+{
+ inode_unlock(d_inode(dir));
+ dput(dir);
+}
+
+static inline int prepare_dir(const char *path_s, uid_t uid, gid_t gid, mode_t mode)
+{
+ int err;
+ struct dentry *dent;
+ struct iattr attrs;
+ struct path parent;
+
+ dent = kern_path_locked(path_s, &parent);
+ if (IS_ERR(dent)) {
+ err = PTR_ERR(dent);
+ if (err == -EEXIST)
+ err = 0;
+ goto out_unlock;
+ }
+
+ err = vfs_mkdir2(parent.mnt, d_inode(parent.dentry), dent, mode);
+ if (err) {
+ if (err == -EEXIST)
+ err = 0;
+ goto out_dput;
+ }
+
+ attrs.ia_uid = make_kuid(&init_user_ns, uid);
+ attrs.ia_gid = make_kgid(&init_user_ns, gid);
+ attrs.ia_valid = ATTR_UID | ATTR_GID;
+ inode_lock(d_inode(dent));
+ notify_change2(parent.mnt, dent, &attrs, NULL);
+ inode_unlock(d_inode(dent));
+
+out_dput:
+ dput(dent);
+
+out_unlock:
+ /* parent dentry locked by lookup_create */
+ inode_unlock(d_inode(parent.dentry));
+ path_put(&parent);
+ return err;
+}
+
+/*
+ * Return 1, if a disk has enough free space, otherwise 0.
+ * We assume that any files can not be overwritten.
+ */
+static inline int check_min_free_space(struct dentry *dentry, size_t size, int dir)
+{
+ int err;
+ struct path lower_path;
+ struct kstatfs statfs;
+ u64 avail;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+
+ if (sbi->options.reserved_mb) {
+ /* Get fs stat of lower filesystem. */
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ err = vfs_statfs(&lower_path, &statfs);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+
+ if (unlikely(err))
+ return 0;
+
+ /* Invalid statfs informations. */
+ if (unlikely(statfs.f_bsize == 0))
+ return 0;
+
+ /* if you are checking directory, set size to f_bsize. */
+ if (unlikely(dir))
+ size = statfs.f_bsize;
+
+ /* available size */
+ avail = statfs.f_bavail * statfs.f_bsize;
+
+ /* not enough space */
+ if ((u64)size > avail)
+ return 0;
+
+ /* enough space */
+ if ((avail - size) > (sbi->options.reserved_mb * 1024 * 1024))
+ return 1;
+
+ return 0;
+ } else
+ return 1;
+}
+
+/*
+ * Copies attrs and maintains sdcardfs managed attrs
+ * Since our permission check handles all special permissions, set those to be open
+ */
+static inline void sdcardfs_copy_and_fix_attrs(struct inode *dest, const struct inode *src)
+{
+ dest->i_mode = (src->i_mode & S_IFMT) | S_IRWXU | S_IRWXG |
+ S_IROTH | S_IXOTH; /* 0775 */
+ dest->i_uid = make_kuid(&init_user_ns, SDCARDFS_I(dest)->data->d_uid);
+ dest->i_gid = make_kgid(&init_user_ns, AID_SDCARD_RW);
+ dest->i_rdev = src->i_rdev;
+ dest->i_atime = src->i_atime;
+ dest->i_mtime = src->i_mtime;
+ dest->i_ctime = src->i_ctime;
+ dest->i_blkbits = src->i_blkbits;
+ dest->i_flags = src->i_flags;
+ set_nlink(dest, src->i_nlink);
+}
+
+static inline bool str_case_eq(const char *s1, const char *s2)
+{
+ return !strcasecmp(s1, s2);
+}
+
+static inline bool str_n_case_eq(const char *s1, const char *s2, size_t len)
+{
+ return !strncasecmp(s1, s2, len);
+}
+
+static inline bool qstr_case_eq(const struct qstr *q1, const struct qstr *q2)
+{
+ return q1->len == q2->len && str_n_case_eq(q1->name, q2->name, q2->len);
+}
+
+#define QSTR_LITERAL(string) QSTR_INIT(string, sizeof(string)-1)
+
+#endif /* not _SDCARDFS_H_ */
diff --git a/fs/sdcardfs/super.c b/fs/sdcardfs/super.c
new file mode 100644
index 0000000..5e0c39a
--- /dev/null
+++ b/fs/sdcardfs/super.c
@@ -0,0 +1,333 @@
+/*
+ * fs/sdcardfs/super.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"
+
+/*
+ * The inode cache is used with alloc_inode for both our inode info and the
+ * vfs inode.
+ */
+static struct kmem_cache *sdcardfs_inode_cachep;
+
+/*
+ * To support the top references, we must track some data separately.
+ * An sdcardfs_inode_info always has a reference to its data, and once set up,
+ * also has a reference to its top. The top may be itself, in which case it
+ * holds two references to its data. When top is changed, it takes a ref to the
+ * new data and then drops the ref to the old data.
+ */
+static struct kmem_cache *sdcardfs_inode_data_cachep;
+
+void data_release(struct kref *ref)
+{
+ struct sdcardfs_inode_data *data =
+ container_of(ref, struct sdcardfs_inode_data, refcount);
+
+ kmem_cache_free(sdcardfs_inode_data_cachep, data);
+}
+
+/* final actions when unmounting a file system */
+static void sdcardfs_put_super(struct super_block *sb)
+{
+ struct sdcardfs_sb_info *spd;
+ struct super_block *s;
+
+ spd = SDCARDFS_SB(sb);
+ if (!spd)
+ return;
+
+ if (spd->obbpath_s) {
+ kfree(spd->obbpath_s);
+ path_put(&spd->obbpath);
+ }
+
+ /* decrement lower super references */
+ s = sdcardfs_lower_super(sb);
+ sdcardfs_set_lower_super(sb, NULL);
+ atomic_dec(&s->s_active);
+
+ kfree(spd);
+ sb->s_fs_info = NULL;
+}
+
+static int sdcardfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ int err;
+ struct path lower_path;
+ u32 min_blocks;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ err = vfs_statfs(&lower_path, buf);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+
+ if (sbi->options.reserved_mb) {
+ /* Invalid statfs informations. */
+ if (buf->f_bsize == 0) {
+ pr_err("Returned block size is zero.\n");
+ return -EINVAL;
+ }
+
+ min_blocks = ((sbi->options.reserved_mb * 1024 * 1024)/buf->f_bsize);
+ buf->f_blocks -= min_blocks;
+
+ if (buf->f_bavail > min_blocks)
+ buf->f_bavail -= min_blocks;
+ else
+ buf->f_bavail = 0;
+
+ /* Make reserved blocks invisiable to media storage */
+ buf->f_bfree = buf->f_bavail;
+ }
+
+ /* set return buf to our f/s to avoid confusing user-level utils */
+ buf->f_type = SDCARDFS_SUPER_MAGIC;
+
+ return err;
+}
+
+/*
+ * @flags: numeric mount options
+ * @options: mount options string
+ */
+static int sdcardfs_remount_fs(struct super_block *sb, int *flags, char *options)
+{
+ int err = 0;
+
+ /*
+ * The VFS will take care of "ro" and "rw" flags among others. We
+ * can safely accept a few flags (RDONLY, MANDLOCK), and honor
+ * SILENT, but anything else left over is an error.
+ */
+ if ((*flags & ~(MS_RDONLY | MS_MANDLOCK | MS_SILENT)) != 0) {
+ pr_err("sdcardfs: remount flags 0x%x unsupported\n", *flags);
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+/*
+ * @mnt: mount point we are remounting
+ * @sb: superblock we are remounting
+ * @flags: numeric mount options
+ * @options: mount options string
+ */
+static int sdcardfs_remount_fs2(struct vfsmount *mnt, struct super_block *sb,
+ int *flags, char *options)
+{
+ int err = 0;
+
+ /*
+ * The VFS will take care of "ro" and "rw" flags among others. We
+ * can safely accept a few flags (RDONLY, MANDLOCK), and honor
+ * SILENT, but anything else left over is an error.
+ */
+ if ((*flags & ~(MS_RDONLY | MS_MANDLOCK | MS_SILENT | MS_REMOUNT)) != 0) {
+ pr_err("sdcardfs: remount flags 0x%x unsupported\n", *flags);
+ err = -EINVAL;
+ }
+ pr_info("Remount options were %s for vfsmnt %p.\n", options, mnt);
+ err = parse_options_remount(sb, options, *flags & ~MS_SILENT, mnt->data);
+
+
+ return err;
+}
+
+static void *sdcardfs_clone_mnt_data(void *data)
+{
+ struct sdcardfs_vfsmount_options *opt = kmalloc(sizeof(struct sdcardfs_vfsmount_options), GFP_KERNEL);
+ struct sdcardfs_vfsmount_options *old = data;
+
+ if (!opt)
+ return NULL;
+ opt->gid = old->gid;
+ opt->mask = old->mask;
+ return opt;
+}
+
+static void sdcardfs_copy_mnt_data(void *data, void *newdata)
+{
+ struct sdcardfs_vfsmount_options *old = data;
+ struct sdcardfs_vfsmount_options *new = newdata;
+
+ old->gid = new->gid;
+ old->mask = new->mask;
+}
+
+/*
+ * Called by iput() when the inode reference count reached zero
+ * and the inode is not hashed anywhere. Used to clear anything
+ * that needs to be, before the inode is completely destroyed and put
+ * on the inode free list.
+ */
+static void sdcardfs_evict_inode(struct inode *inode)
+{
+ struct inode *lower_inode;
+
+ truncate_inode_pages(&inode->i_data, 0);
+ set_top(SDCARDFS_I(inode), NULL);
+ clear_inode(inode);
+ /*
+ * Decrement a reference to a lower_inode, which was incremented
+ * by our read_inode when it was created initially.
+ */
+ lower_inode = sdcardfs_lower_inode(inode);
+ sdcardfs_set_lower_inode(inode, NULL);
+ iput(lower_inode);
+}
+
+static struct inode *sdcardfs_alloc_inode(struct super_block *sb)
+{
+ struct sdcardfs_inode_info *i;
+ struct sdcardfs_inode_data *d;
+
+ i = kmem_cache_alloc(sdcardfs_inode_cachep, GFP_KERNEL);
+ if (!i)
+ return NULL;
+
+ /* memset everything up to the inode to 0 */
+ memset(i, 0, offsetof(struct sdcardfs_inode_info, vfs_inode));
+
+ d = kmem_cache_alloc(sdcardfs_inode_data_cachep,
+ GFP_KERNEL | __GFP_ZERO);
+ if (!d) {
+ kmem_cache_free(sdcardfs_inode_cachep, i);
+ return NULL;
+ }
+
+ i->data = d;
+ kref_init(&d->refcount);
+ i->top_data = d;
+ spin_lock_init(&i->top_lock);
+ kref_get(&d->refcount);
+
+ inode_set_iversion(&i->vfs_inode, 1);
+ return &i->vfs_inode;
+}
+
+static void i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+
+ release_own_data(SDCARDFS_I(inode));
+ kmem_cache_free(sdcardfs_inode_cachep, SDCARDFS_I(inode));
+}
+
+static void sdcardfs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, i_callback);
+}
+
+/* sdcardfs inode cache constructor */
+static void init_once(void *obj)
+{
+ struct sdcardfs_inode_info *i = obj;
+
+ inode_init_once(&i->vfs_inode);
+}
+
+int sdcardfs_init_inode_cache(void)
+{
+ sdcardfs_inode_cachep =
+ kmem_cache_create("sdcardfs_inode_cache",
+ sizeof(struct sdcardfs_inode_info), 0,
+ SLAB_RECLAIM_ACCOUNT, init_once);
+
+ if (!sdcardfs_inode_cachep)
+ return -ENOMEM;
+
+ sdcardfs_inode_data_cachep =
+ kmem_cache_create("sdcardfs_inode_data_cache",
+ sizeof(struct sdcardfs_inode_data), 0,
+ SLAB_RECLAIM_ACCOUNT, NULL);
+ if (!sdcardfs_inode_data_cachep) {
+ kmem_cache_destroy(sdcardfs_inode_cachep);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/* sdcardfs inode cache destructor */
+void sdcardfs_destroy_inode_cache(void)
+{
+ kmem_cache_destroy(sdcardfs_inode_data_cachep);
+ kmem_cache_destroy(sdcardfs_inode_cachep);
+}
+
+/*
+ * Used only in nfs, to kill any pending RPC tasks, so that subsequent
+ * code can actually succeed and won't leave tasks that need handling.
+ */
+static void sdcardfs_umount_begin(struct super_block *sb)
+{
+ struct super_block *lower_sb;
+
+ lower_sb = sdcardfs_lower_super(sb);
+ if (lower_sb && lower_sb->s_op && lower_sb->s_op->umount_begin)
+ lower_sb->s_op->umount_begin(lower_sb);
+}
+
+static int sdcardfs_show_options(struct vfsmount *mnt, struct seq_file *m,
+ struct dentry *root)
+{
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(root->d_sb);
+ struct sdcardfs_mount_options *opts = &sbi->options;
+ struct sdcardfs_vfsmount_options *vfsopts = mnt->data;
+
+ if (opts->fs_low_uid != 0)
+ seq_printf(m, ",fsuid=%u", opts->fs_low_uid);
+ if (opts->fs_low_gid != 0)
+ seq_printf(m, ",fsgid=%u", opts->fs_low_gid);
+ if (vfsopts->gid != 0)
+ seq_printf(m, ",gid=%u", vfsopts->gid);
+ if (opts->multiuser)
+ seq_puts(m, ",multiuser");
+ if (vfsopts->mask)
+ seq_printf(m, ",mask=%u", vfsopts->mask);
+ if (opts->fs_user_id)
+ seq_printf(m, ",userid=%u", opts->fs_user_id);
+ if (opts->gid_derivation)
+ seq_puts(m, ",derive_gid");
+ if (opts->default_normal)
+ seq_puts(m, ",default_normal");
+ if (opts->reserved_mb != 0)
+ seq_printf(m, ",reserved=%uMB", opts->reserved_mb);
+ if (opts->nocache)
+ seq_printf(m, ",nocache");
+
+ return 0;
+};
+
+const struct super_operations sdcardfs_sops = {
+ .put_super = sdcardfs_put_super,
+ .statfs = sdcardfs_statfs,
+ .remount_fs = sdcardfs_remount_fs,
+ .remount_fs2 = sdcardfs_remount_fs2,
+ .clone_mnt_data = sdcardfs_clone_mnt_data,
+ .copy_mnt_data = sdcardfs_copy_mnt_data,
+ .evict_inode = sdcardfs_evict_inode,
+ .umount_begin = sdcardfs_umount_begin,
+ .show_options2 = sdcardfs_show_options,
+ .alloc_inode = sdcardfs_alloc_inode,
+ .destroy_inode = sdcardfs_destroy_inode,
+ .drop_inode = generic_delete_inode,
+};