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(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
return err;
}
// 2014.10.11 merge vm_operations_struct->page_mkwrite from latest wrapfs to fix kernel panic,
// when using filemap in lenovo gallery apk
static int sdcardfs_page_mkwrite(struct vm_area_struct *vma,
struct vm_fault *vmf)
{
int err = 0;
struct file *file, *lower_file;
const struct vm_operations_struct *lower_vm_ops;
struct vm_area_struct lower_vma;
SDFS_DBG(" Just DBG: sdcardfs page_mkwrite ! \n");
memcpy(&lower_vma, vma, sizeof(struct vm_area_struct));
file = lower_vma.vm_file;
lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
BUG_ON(!lower_vm_ops);
if (!lower_vm_ops->page_mkwrite)
goto out;
lower_file = sdcardfs_lower_file(file);
/*
* XXX: vm_ops->page_mkwrite may be called in parallel.
* Because we have to resort to temporarily changing the
* vma->vm_file to point to the lower file, a concurrent
* invocation of sdcardfs_page_mkwrite could see a different
* value. In this workaround, we keep a different copy of the
* vma structure in our stack, so we never expose a different
* value of the vma->vm_file called to us, even temporarily.
* A better fix would be to change the calling semantics of
* ->page_mkwrite to take an explicit file pointer.
*/
lower_vma.vm_file = lower_file;
err = lower_vm_ops->page_mkwrite(&lower_vma, vmf);
out:
return err;
}
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;
printk(KERN_ERR "sdcardfs: lower file system does not "
"support writeable mmap\n");
goto out;
}
/* BEGIN PN:DTS2014082500731 , Modified by d00168349, 2014/08/25 */
/*
* 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) {
printk(KERN_ERR "sdcardfs: lower mmap failed %d\n",
err);
goto out;
}
}
/*
* 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);
fput(file);
get_file(lower_file);
vma->vm_file = lower_file;
/* DTS2014061002949 for sdcardfs file mmap problem end */
/* END PN:DTS2014082500731 , Modified by d00168349, 2014/08/25 */
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;
out:
return err;
}
static ssize_t sdcardfs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int err = 0;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
/* check disk space */
if (!check_min_free_space(dentry, count, 0)) {
printk(KERN_INFO "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) {
fsstack_copy_inode_size(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
fsstack_copy_attr_times(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
}
return err;
}
static int sdcardfs_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
int err;
struct file *file, *lower_file;
const struct vm_operations_struct *lower_vm_ops;
struct vm_area_struct lower_vma;
memcpy(&lower_vma, vma, sizeof(struct vm_area_struct));
file = lower_vma.vm_file;
lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
BUG_ON(!lower_vm_ops);
lower_file = sdcardfs_lower_file(file);
/*
* XXX: vm_ops->fault may be called in parallel. Because we have to
* resort to temporarily changing the vma->vm_file to point to the
* lower file, a concurrent invocation of sdcardfs_fault could see a
* different value. In this workaround, we keep a different copy of
* the vma structure in our stack, so we never expose a different
* value of the vma->vm_file called to us, even temporarily. A
* better fix would be to change the calling semantics of ->fault to
* take an explicit file pointer.
*/
lower_vma.vm_file = lower_file;
err = lower_vm_ops->fault(&lower_vma, vmf);
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;
}
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)
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, int datasync)
{
int err;
struct file *lower_file;
struct path lower_path;
struct dentry *dentry = file->f_path.dentry;
lower_file = sdcardfs_lower_file(file);
sdcardfs_get_lower_path(dentry, &lower_path);
err = vfs_fsync(lower_file, datasync);
sdcardfs_put_lower_path(dentry, &lower_path);
return err;
}
static int sdcardfs_readdir(struct file *file, struct dir_context *ctx)
{
int err = 0;
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(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
return err;
}
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;
lower_file = sdcardfs_lower_file(file);
err = vfs_read(lower_file, buf, count, ppos);
/* update our inode atime upon a successful lower read */
if (err >= 0)
fsstack_copy_attr_atime(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
return err;
}
static int sdcardfs_readdir(struct file *file, void *dirent, filldir_t filldir)
{
int err = 0;
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 = vfs_readdir(lower_file, filldir, dirent);
file->f_pos = lower_file->f_pos;
if (err >= 0) /* copy the atime */
fsstack_copy_attr_atime(dentry->d_inode,
lower_file->f_path.dentry->d_inode);
return err;
}
static long sdcardfs_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
long err = -ENOTTY;
struct file *lower_file;
lower_file = sdcardfs_lower_file(file);
/* XXX: use vfs_ioctl if/when VFS exports it */
if (!lower_file || !lower_file->f_op)
goto out;
if (lower_file->f_op->compat_ioctl)
err = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
out:
return err;
}
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;
#ifdef CONFIG_TIMA_IOMMU_OPT
if (vma->vm_end - vma->vm_start) {
/* iommu optimization- needs to be turned ON from
* the tz side.
*/
cpu_v7_tima_iommu_opt(vma->vm_start, vma->vm_end, (unsigned long)vma->vm_mm->pgd);
}
#endif /* CONFIG_TIMA_IOMMU_OPT */
/* 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;
printk(KERN_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) {
printk(KERN_ERR "sdcardfs: lower mmap failed %d\n", err);
goto out;
}
saved_vm_ops = vma->vm_ops; /* save: came from lower ->mmap */
err = do_munmap(current->mm, vma->vm_start,
vma->vm_end - vma->vm_start);
if (err) {
printk(KERN_ERR "sdcardfs: do_munmap failed %d\n", err);
goto out;
}
}
/*
* 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;
out:
return err;
}
static struct file *sdcardfs_get_lower_file(struct file *f)
{
return sdcardfs_lower_file(f);
}
static int sdcardfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct inode *inode;
struct inode *lower_inode;
struct path lower_path;
struct iattr lower_ia;
struct dentry *parent;
inode = dentry->d_inode;
/*
* Check if user has permission to change inode. We don't check if
* this user can change the lower inode: that should happen when
* calling notify_change on the lower inode.
*/
err = inode_change_ok(inode, ia);
/* no vfs_XXX operations required, cred overriding will be skipped. wj*/
if (!err) {
/* check the Android group ID */
parent = dget_parent(dentry);
if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
}
dput(parent);
}
if (err)
goto out_err;
sdcardfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_inode = sdcardfs_lower_inode(inode);
/* prepare our own lower struct iattr (with the lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
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) {
loff_t oldsize;
err = inode_newsize_ok(inode, ia->ia_size);
if (err)
goto out;
/* This code from truncate_setsize(). We need to add spin_lock
* to avoid race condition with fsstack_copy_inode_size() */
oldsize = i_size_read(inode);
if (sizeof(ia->ia_size) > sizeof(long))
spin_lock(&inode->i_lock);
i_size_write(inode, ia->ia_size);
if (sizeof(ia->ia_size) > sizeof(long))
spin_unlock(&inode->i_lock);
if (ia->ia_size > oldsize)
pagecache_isize_extended(inode, oldsize, ia->ia_size);
truncate_pagecache(inode, oldsize, 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 lower_dentry->d_inode, 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.
*/
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia); /* note: lower_ia */
mutex_unlock(&lower_dentry->d_inode->i_mutex);
if (err)
goto out;
/* get attributes from the lower inode, i_mutex held */
sdcardfs_copy_inode_attr(inode, lower_inode);
/* update derived permission of the upper inode */
fix_derived_permission(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);
out_err:
return err;
}
static int sdcardfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct inode *inode;
struct inode *lower_inode;
struct path lower_path;
struct iattr lower_ia;
inode = dentry->d_inode;
/*
* Check if user has permission to change inode. We don't check if
* this user can change the lower inode: that should happen when
* calling notify_change on the lower inode.
*/
err = inode_change_ok(inode, ia);
if (err)
goto out_err;
sdcardfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_inode = sdcardfs_lower_inode(inode);
/* fix warpfs file owner and permission. cannot change them. */
ia->ia_uid = AID_ROOT;
ia->ia_gid = AID_SDCARD_RW;
fix_mode(ia->ia_mode);
/* prepare our own lower struct iattr (with the lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE)
lower_ia.ia_file = sdcardfs_lower_file(ia->ia_file);
lower_ia.ia_uid = AID_MEDIA_RW;
lower_ia.ia_gid = AID_MEDIA_RW;
fix_mode(lower_ia.ia_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(inode, ia->ia_size);
if (err)
goto out;
truncate_setsize(inode, ia->ia_size);
}
/* for FAT emulation */
/*
* 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 lower_dentry->d_inode, 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.
*/
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia); /* note: lower_ia */
mutex_unlock(&lower_dentry->d_inode->i_mutex);
if (err)
goto out;
/* get attributes from the lower inode */
fsstack_copy_attr_all(inode, lower_inode);
fix_fat_permission(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);
out_err:
return err;
}
static int sdcardfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct inode *inode;
struct inode *lower_inode;
struct path lower_path;
struct iattr lower_ia;
struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
struct dentry *parent;
int has_rw;
inode = dentry->d_inode;
/*
* Check if user has permission to change inode. We don't check if
* this user can change the lower inode: that should happen when
* calling notify_change on the lower inode.
*/
err = inode_change_ok(inode, ia);
/* no vfs_XXX operations required, cred overriding will be skipped. wj*/
if (!err) {
/* check the Android group ID */
has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
parent = dget_parent(dentry);
if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name,
sbi->options.derive, 1, has_rw))
err = -EACCES;
dput(parent);
}
if (err)
goto out_err;
sdcardfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_inode = sdcardfs_lower_inode(inode);
/* prepare our own lower struct iattr (with the lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
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.
*/
down_write(¤t->mm->mmap_sem);
if (ia->ia_valid & ATTR_SIZE) {
err = inode_newsize_ok(inode, ia->ia_size);
if (err) {
up_write(¤t->mm->mmap_sem);
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 lower_dentry->d_inode, 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.
*/
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia); /* note: lower_ia */
mutex_unlock(&lower_dentry->d_inode->i_mutex);
up_write(¤t->mm->mmap_sem);
if (err)
goto out;
/* get attributes from the lower inode */
fsstack_copy_attr_all(inode, lower_inode);
/* update derived permission of the upper inode */
fix_derived_permission(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);
out_err:
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;
int has_rw;
/* don't open unhashed/deleted files */
if (d_unhashed(dentry)) {
err = -ENOENT;
goto out_err;
}
has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name,
sbi->options.derive,
open_flags_to_access_mode(file->f_flags), has_rw)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
err = -EACCES;
goto out_err;
}
/* save current_cred and override it */
OVERRIDE_CRED(sbi, saved_cred);
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.dentry, lower_path.mnt,
file->f_flags, current_cred());
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 {
fsstack_copy_attr_all(inode, sdcardfs_lower_inode(inode));
fix_derived_permission(inode);
}
out_revert_cred:
REVERT_CRED(saved_cred);
out_err:
dput(parent);
return err;
}
