diff options
Diffstat (limited to 'fs/sdcardfs')
| -rw-r--r-- | fs/sdcardfs/Kconfig | 13 | ||||
| -rw-r--r-- | fs/sdcardfs/Makefile | 7 | ||||
| -rw-r--r-- | fs/sdcardfs/dentry.c | 186 | ||||
| -rw-r--r-- | fs/sdcardfs/derived_perm.c | 265 | ||||
| -rw-r--r-- | fs/sdcardfs/file.c | 356 | ||||
| -rw-r--r-- | fs/sdcardfs/inode.c | 802 | ||||
| -rw-r--r-- | fs/sdcardfs/lookup.c | 384 | ||||
| -rw-r--r-- | fs/sdcardfs/main.c | 402 | ||||
| -rw-r--r-- | fs/sdcardfs/mmap.c | 81 | ||||
| -rw-r--r-- | fs/sdcardfs/multiuser.h | 37 | ||||
| -rw-r--r-- | fs/sdcardfs/packagelist.c | 437 | ||||
| -rw-r--r-- | fs/sdcardfs/sdcardfs.h | 530 | ||||
| -rw-r--r-- | fs/sdcardfs/super.c | 222 |
13 files changed, 3722 insertions, 0 deletions
diff --git a/fs/sdcardfs/Kconfig b/fs/sdcardfs/Kconfig new file mode 100644 index 000000000000..a1c103316ac7 --- /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 000000000000..b84fbb2b45a4 --- /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 000000000000..971928ab6c21 --- /dev/null +++ b/fs/sdcardfs/dentry.c @@ -0,0 +1,186 @@ +/* + * 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; + + 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)) { + d_drop(dentry); + return 0; + } + + parent_dentry = dget_parent(dentry); + sdcardfs_get_lower_path(parent_dentry, &parent_lower_path); + sdcardfs_get_real_lower(dentry, &lower_path); + parent_lower_dentry = parent_lower_path.dentry; + lower_dentry = lower_path.dentry; + lower_cur_parent_dentry = dget_parent(lower_dentry); + + spin_lock(&lower_dentry->d_lock); + if (d_unhashed(lower_dentry)) { + spin_unlock(&lower_dentry->d_lock); + d_drop(dentry); + err = 0; + goto out; + } + spin_unlock(&lower_dentry->d_lock); + + if (parent_lower_dentry != lower_cur_parent_dentry) { + d_drop(dentry); + err = 0; + goto out; + } + + if (dentry < lower_dentry) { + spin_lock(&dentry->d_lock); + spin_lock(&lower_dentry->d_lock); + } else { + spin_lock(&lower_dentry->d_lock); + spin_lock(&dentry->d_lock); + } + + if (dentry->d_name.len != lower_dentry->d_name.len) { + __d_drop(dentry); + err = 0; + } else if (strncasecmp(dentry->d_name.name, lower_dentry->d_name.name, + dentry->d_name.len) != 0) { + __d_drop(dentry); + err = 0; + } + + if (dentry < lower_dentry) { + spin_unlock(&lower_dentry->d_lock); + spin_unlock(&dentry->d_lock); + } else { + spin_unlock(&dentry->d_lock); + spin_unlock(&lower_dentry->d_lock); + } + +out: + dput(parent_dentry); + dput(lower_cur_parent_dentry); + sdcardfs_put_lower_path(parent_dentry, &parent_lower_path); + sdcardfs_put_real_lower(dentry, &lower_path); + return err; +} + +static void sdcardfs_d_release(struct dentry *dentry) +{ + /* release and reset the lower paths */ + if(has_graft_path(dentry)) { + sdcardfs_put_reset_orig_path(dentry); + } + sdcardfs_put_reset_lower_path(dentry); + free_dentry_private_data(dentry); + return; +} + +static int sdcardfs_hash_ci(const struct dentry *dentry, + struct qstr *qstr) +{ + /* + * This function is copy of vfat_hashi. + * FIXME Should we support national language? + * Refer to vfat_hashi() + * struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; + */ + const unsigned char *name; + unsigned int len; + unsigned long hash; + + name = qstr->name; + //len = vfat_striptail_len(qstr); + len = qstr->len; + + hash = init_name_hash(); + while (len--) + //hash = partial_name_hash(nls_tolower(t, *name++), hash); + hash = partial_name_hash(tolower(*name++), hash); + qstr->hash = end_name_hash(hash); + + return 0; +} + +/* + * Case insensitive compare of two vfat names. + */ +static int sdcardfs_cmp_ci(const struct dentry *parent, + const struct dentry *dentry, + unsigned int len, const char *str, const struct qstr *name) +{ + /* This function is copy of vfat_cmpi */ + // FIXME Should we support national language? + //struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io; + //unsigned int alen, blen; + + /* A filename cannot end in '.' or we treat it like it has none */ + /* + alen = vfat_striptail_len(name); + blen = __vfat_striptail_len(len, str); + if (alen == blen) { + if (nls_strnicmp(t, name->name, str, alen) == 0) + return 0; + } + */ + if (name->len == len) { + if (strncasecmp(name->name, str, len) == 0) + return 0; + } + return 1; +} + +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_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 000000000000..128b3e56851f --- /dev/null +++ b/fs/sdcardfs/derived_perm.c @@ -0,0 +1,265 @@ +/* + * 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->perm = PERM_INHERIT; + ci->userid = pi->userid; + ci->d_uid = pi->d_uid; + ci->under_android = pi->under_android; +} + +/* helper function for derived state */ +void setup_derived_state(struct inode *inode, perm_t perm, + userid_t userid, uid_t uid, bool under_android) +{ + struct sdcardfs_inode_info *info = SDCARDFS_I(inode); + + info->perm = perm; + info->userid = userid; + info->d_uid = uid; + info->under_android = under_android; +} + +/* 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, struct dentry *newdentry) +{ + struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb); + struct sdcardfs_inode_info *info = SDCARDFS_I(dentry->d_inode); + struct sdcardfs_inode_info *parent_info= SDCARDFS_I(parent->d_inode); + appid_t appid; + + /* 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. + * The derived state will be updated on the last + * stage of each system call by fix_derived_permission(inode). + */ + + inherit_derived_state(parent->d_inode, dentry->d_inode); + + /* Derive custom permissions based on parent and current node */ + switch (parent_info->perm) { + case PERM_INHERIT: + /* Already inherited above */ + break; + case PERM_PRE_ROOT: + /* Legacy internal layout places users at top level */ + info->perm = PERM_ROOT; + info->userid = simple_strtoul(newdentry->d_name.name, NULL, 10); + break; + case PERM_ROOT: + /* Assume masked off by default. */ + if (!strcasecmp(newdentry->d_name.name, "Android")) { + /* App-specific directories inside; let anyone traverse */ + info->perm = PERM_ANDROID; + info->under_android = true; + } + break; + case PERM_ANDROID: + if (!strcasecmp(newdentry->d_name.name, "data")) { + /* App-specific directories inside; let anyone traverse */ + info->perm = PERM_ANDROID_DATA; + } else if (!strcasecmp(newdentry->d_name.name, "obb")) { + /* App-specific directories inside; let anyone traverse */ + info->perm = PERM_ANDROID_OBB; + /* Single OBB directory is always shared */ + } else if (!strcasecmp(newdentry->d_name.name, "media")) { + /* App-specific directories inside; let anyone traverse */ + info->perm = PERM_ANDROID_MEDIA; + } + break; + case PERM_ANDROID_DATA: + case PERM_ANDROID_OBB: + case PERM_ANDROID_MEDIA: + appid = get_appid(sbi->pkgl_id, newdentry->d_name.name); + if (appid != 0) { + info->d_uid = multiuser_get_uid(parent_info->userid, appid); + } + break; + } +} + +void get_derived_permission(struct dentry *parent, struct dentry *dentry) +{ + get_derived_permission_new(parent, dentry, dentry); +} + +void get_derive_permissions_recursive(struct dentry *parent) { + struct dentry *dentry; + list_for_each_entry(dentry, &parent->d_subdirs, d_child) { + if (dentry && dentry->d_inode) { + mutex_lock(&dentry->d_inode->i_mutex); + get_derived_permission(parent, dentry); + fix_derived_permission(dentry->d_inode); + get_derive_permissions_recursive(dentry); + mutex_unlock(&dentry->d_inode->i_mutex); + } + } +} + +/* main function for updating derived permission */ +inline void update_derived_permission_lock(struct dentry *dentry) +{ + struct dentry *parent; + + if(!dentry || !dentry->d_inode) { + printk(KERN_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 + */ + mutex_lock(&dentry->d_inode->i_mutex); + if(IS_ROOT(dentry)) { + //setup_default_pre_root_state(dentry->d_inode); + } else { + parent = dget_parent(dentry); + if(parent) { + get_derived_permission(parent, dentry); + dput(parent); + } + } + fix_derived_permission(dentry->d_inode); + mutex_unlock(&dentry->d_inode->i_mutex); +} + +int need_graft_path(struct dentry *dentry) +{ + int ret = 0; + struct dentry *parent = dget_parent(dentry); + struct sdcardfs_inode_info *parent_info= SDCARDFS_I(parent->d_inode); + struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb); + + if(parent_info->perm == PERM_ANDROID && + !strcasecmp(dentry->d_name.name, "obb")) { + + /* /Android/obb is the base obbpath of DERIVED_UNIFIED */ + if(!(sbi->options.multiuser == false + && parent_info->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; + + /* 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); + //lower_parent = lock_parent(lower_path->dentry); + + path_buf = kmalloc(PATH_MAX, GFP_ATOMIC); + if(!path_buf) { + ret = 1; + printk(KERN_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) || + strcasecmp(sbi->obbpath_s, obbpath_s)) { + ret = 1; + } + kfree(path_buf); + } + + //unlock_dir(lower_parent); + path_put(&di->lower_path); + } + } + spin_unlock(&di->lock); + 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(parent->d_inode); + struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb); + + spin_lock(&SDCARDFS_D(dentry)->lock); + if (sbi->options.multiuser) { + if(parent_info->perm == PERM_PRE_ROOT && + !strcasecmp(dentry->d_name.name, "obb")) { + ret = 1; + } + } else if (parent_info->perm == PERM_ANDROID && + !strcasecmp(dentry->d_name.name, "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 */ + printk(KERN_INFO "sdcardfs: the sbi->obbpath is found\n"); + 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. */ + printk(KERN_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 000000000000..c249fa982d3c --- /dev/null +++ b/fs/sdcardfs/file.c @@ -0,0 +1,356 @@ +/* + * 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; + + /* 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(d_inode(dentry), + file_inode(lower_file)); + fsstack_copy_attr_times(d_inode(dentry), + file_inode(lower_file)); + } + + 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; + + 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->unlocked_ioctl) + err = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); + +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; + + 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; +} +#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; + 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 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(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; + 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, 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_CRED(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; +} + +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, +}; + +/* trimmed directory options */ +const struct file_operations sdcardfs_dir_fops = { + .llseek = generic_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 000000000000..2528da0d3ae1 --- /dev/null +++ b/fs/sdcardfs/inode.c @@ -0,0 +1,802 @@ +/* + * 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" + +/* Do not directly use this function. Use OVERRIDE_CRED() instead. */ +const struct cred * override_fsids(struct sdcardfs_sb_info* sbi) +{ + struct cred * cred; + const struct cred * old_cred; + + cred = prepare_creds(); + if (!cred) + return NULL; + + cred->fsuid = make_kuid(&init_user_ns, sbi->options.fs_low_uid); + cred->fsgid = make_kgid(&init_user_ns, sbi->options.fs_low_gid); + + old_cred = override_creds(cred); + + return old_cred; +} + +/* Do not directly use this function, use REVERT_CRED() instead. */ +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 dentry *lower_parent_dentry = NULL; + struct path lower_path; + const struct cred *saved_cred = NULL; + + if(!check_caller_access_to_name(dir, 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; + goto out_eacces; + } + + /* save current_cred and override it */ + OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); + + sdcardfs_get_lower_path(dentry, &lower_path); + lower_dentry = lower_path.dentry; + lower_parent_dentry = lock_parent(lower_dentry); + + /* set last 16bytes of mode field to 0664 */ + mode = (mode & S_IFMT) | 00664; + err = vfs_create(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)->userid); + if (err) + goto out; + fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir)); + fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry)); + +out: + unlock_dir(lower_parent_dentry); + sdcardfs_put_lower_path(dentry, &lower_path); + REVERT_CRED(saved_cred); +out_eacces: + return err; +} + +#if 0 +static int sdcardfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + struct dentry *lower_old_dentry; + struct dentry *lower_new_dentry; + struct dentry *lower_dir_dentry; + u64 file_size_save; + int err; + struct path lower_old_path, lower_new_path; + + OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb)); + + file_size_save = i_size_read(d_inode(old_dentry)); + sdcardfs_get_lower_path(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_dir_dentry = lock_parent(lower_new_dentry); + + err = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry), + lower_new_dentry, NULL); + if (err || !d_inode(lower_new_dentry)) + goto out; + + err = sdcardfs_interpose(new_dentry, dir->i_sb, &lower_new_path); + if (err) + goto out; + fsstack_copy_attr_times(dir, d_inode(lower_new_dentry)); + fsstack_copy_inode_size(dir, d_inode(lower_new_dentry)); + set_nlink(d_inode(old_dentry), + sdcardfs_lower_inode(d_inode(old_dentry))->i_nlink); + i_size_write(d_inode(new_dentry), file_size_save); +out: + unlock_dir(lower_dir_dentry); + sdcardfs_put_lower_path(old_dentry, &lower_old_path); + sdcardfs_put_lower_path(new_dentry, &lower_new_path); + REVERT_CRED(); + return err; +} +#endif + +static int sdcardfs_unlink(struct inode *dir, struct dentry *dentry) +{ + int err; + struct dentry *lower_dentry; + 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.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; + goto out_eacces; + } + + /* save current_cred and override it */ + OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); + + sdcardfs_get_lower_path(dentry, &lower_path); + lower_dentry = lower_path.dentry; + dget(lower_dentry); + lower_dir_dentry = lock_parent(lower_dentry); + + err = vfs_unlink(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_CRED(saved_cred); +out_eacces: + return err; +} + +#if 0 +static int sdcardfs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + int err; + struct dentry *lower_dentry; + struct dentry *lower_parent_dentry = NULL; + struct path lower_path; + + OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb)); + + sdcardfs_get_lower_path(dentry, &lower_path); + lower_dentry = lower_path.dentry; + lower_parent_dentry = lock_parent(lower_dentry); + + err = vfs_symlink(d_inode(lower_parent_dentry), lower_dentry, symname); + if (err) + goto out; + err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path); + if (err) + goto out; + fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir)); + fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry)); + +out: + unlock_dir(lower_parent_dentry); + sdcardfs_put_lower_path(dentry, &lower_path); + REVERT_CRED(); + return err; +} +#endif + +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 { + printk(KERN_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 dentry *lower_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_info *pi = SDCARDFS_I(dir); + char *page_buf; + char *nomedia_dir_name; + char *nomedia_fullpath; + int fullpath_namelen; + int touch_err = 0; + + if(!check_caller_access_to_name(dir, 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; + goto out_eacces; + } + + /* save current_cred and override it */ + OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); + + /* check disk space */ + if (!check_min_free_space(dentry, 0, 1)) { + printk(KERN_INFO "sdcardfs: No minimum free space.\n"); + err = -ENOSPC; + goto out_revert; + } + + /* the lower_dentry is negative here */ + sdcardfs_get_lower_path(dentry, &lower_path); + lower_dentry = lower_path.dentry; + lower_parent_dentry = lock_parent(lower_dentry); + + /* set last 16bytes of mode field to 0775 */ + mode = (mode & S_IFMT) | 00775; + err = vfs_mkdir(d_inode(lower_parent_dentry), lower_dentry, mode); + + if (err) + 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, pi->userid); + if (err) + 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); + + if ((!sbi->options.multiuser) && (!strcasecmp(dentry->d_name.name, "obb")) + && (pi->perm == PERM_ANDROID) && (pi->userid == 0)) + make_nomedia_in_obb = 1; + + /* When creating /Android/data and /Android/obb, mark them as .nomedia */ + if (make_nomedia_in_obb || + ((pi->perm == PERM_ANDROID) && (!strcasecmp(dentry->d_name.name, "data")))) { + + page_buf = (char *)__get_free_page(GFP_KERNEL); + if (!page_buf) { + printk(KERN_ERR "sdcardfs: failed to allocate page buf\n"); + goto out; + } + + nomedia_dir_name = d_absolute_path(&lower_path, page_buf, PAGE_SIZE); + if (IS_ERR(nomedia_dir_name)) { + free_page((unsigned long)page_buf); + printk(KERN_ERR "sdcardfs: failed to get .nomedia dir name\n"); + goto out; + } + + fullpath_namelen = page_buf + PAGE_SIZE - nomedia_dir_name - 1; + fullpath_namelen += strlen("/.nomedia"); + nomedia_fullpath = kzalloc(fullpath_namelen + 1, GFP_KERNEL); + if (!nomedia_fullpath) { + free_page((unsigned long)page_buf); + printk(KERN_ERR "sdcardfs: failed to allocate .nomedia fullpath buf\n"); + goto out; + } + + strcpy(nomedia_fullpath, nomedia_dir_name); + free_page((unsigned long)page_buf); + strcat(nomedia_fullpath, "/.nomedia"); + touch_err = touch(nomedia_fullpath, 0664); + if (touch_err) { + printk(KERN_ERR "sdcardfs: failed to touch(%s): %d\n", + nomedia_fullpath, touch_err); + kfree(nomedia_fullpath); + goto out; + } + kfree(nomedia_fullpath); + } +out: + unlock_dir(lower_parent_dentry); + sdcardfs_put_lower_path(dentry, &lower_path); +out_revert: + REVERT_CRED(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; + int err; + struct path lower_path; + const struct cred *saved_cred = NULL; + + if(!check_caller_access_to_name(dir, 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; + goto out_eacces; + } + + /* save current_cred and override it */ + OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred); + + /* 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_dir_dentry = lock_parent(lower_dentry); + + err = vfs_rmdir(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_CRED(saved_cred); +out_eacces: + return err; +} + +#if 0 +static int sdcardfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, + dev_t dev) +{ + int err; + struct dentry *lower_dentry; + struct dentry *lower_parent_dentry = NULL; + struct path lower_path; + + OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb)); + + sdcardfs_get_lower_path(dentry, &lower_path); + lower_dentry = lower_path.dentry; + lower_parent_dentry = lock_parent(lower_dentry); + + err = vfs_mknod(d_inode(lower_parent_dentry), lower_dentry, mode, dev); + if (err) + goto out; + + err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path); + if (err) + goto out; + fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir)); + fsstack_copy_inode_size(dir, d_inode(lower_parent_dentry)); + +out: + unlock_dir(lower_parent_dentry); + sdcardfs_put_lower_path(dentry, &lower_path); + REVERT_CRED(); + return err; +} +#endif + +/* + * 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) +{ + 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 dentry *trap = NULL; + struct dentry *new_parent = NULL; + struct path lower_old_path, lower_new_path; + const struct cred *saved_cred = NULL; + + if(!check_caller_access_to_name(old_dir, old_dentry->d_name.name) || + !check_caller_access_to_name(new_dir, new_dentry->d_name.name)) { + printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n" + " new_dentry: %s, task:%s\n", + __func__, new_dentry->d_name.name, current->comm); + err = -EACCES; + goto out_eacces; + } + + /* save current_cred and override it */ + OVERRIDE_CRED(SDCARDFS_SB(old_dir->i_sb), saved_cred); + + 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_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_rename(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)); + + /* update the derived permission of the old_dentry + * with its new parent + */ + new_parent = dget_parent(new_dentry); + if(new_parent) { + if(d_inode(old_dentry)) { + update_derived_permission_lock(old_dentry); + } + dput(new_parent); + } + } + /* At this point, not all dentry information has been moved, so + * we pass along new_dentry for the name.*/ + mutex_lock(&d_inode(old_dentry)->i_mutex); + get_derived_permission_new(new_dentry->d_parent, old_dentry, new_dentry); + fix_derived_permission(d_inode(old_dentry)); + get_derive_permissions_recursive(old_dentry); + mutex_unlock(&d_inode(old_dentry)->i_mutex); +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_CRED(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(struct inode *inode, int mask) +{ + int err; + + /* + * Permission check on sdcardfs inode. + * Calling process should have AID_SDCARD_RW permission + */ + err = generic_permission(inode, mask); + + /* XXX + * Original sdcardfs code calls inode_permission(lower_inode,.. ) + * for checking inode permission. But doing such things here seems + * duplicated work, because the functions called after this func, + * such as vfs_create, vfs_unlink, vfs_rename, and etc, + * does exactly same thing, i.e., they calls inode_permission(). + * So we just let they do the things. + * If there are any security hole, just uncomment following if block. + */ +#if 0 + if (!err) { + /* + * Permission check on lower_inode(=EXT4). + * we check it with AID_MEDIA_RW permission + */ + struct inode *lower_inode; + OVERRIDE_CRED(SDCARDFS_SB(inode->sb)); + + lower_inode = sdcardfs_lower_inode(inode); + err = inode_permission(lower_inode, mask); + + REVERT_CRED(); + } +#endif + return err; + +} + +static int sdcardfs_setattr(struct dentry *dentry, struct iattr *ia) +{ + int err; + struct dentry *lower_dentry; + struct inode *inode; + struct inode *lower_inode; + struct path lower_path; + struct iattr lower_ia; + struct dentry *parent; + + inode = d_inode(dentry); + + /* + * 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(d_inode(parent), 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 (current->mm) + down_write(¤t->mm->mmap_sem); + if (ia->ia_valid & ATTR_SIZE) { + err = inode_newsize_ok(inode, ia->ia_size); + if (err) { + if (current->mm) + 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 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. + */ + mutex_lock(&d_inode(lower_dentry)->i_mutex); + err = notify_change(lower_dentry, &lower_ia, /* note: lower_ia */ + NULL); + mutex_unlock(&d_inode(lower_dentry)->i_mutex); + if (current->mm) + up_write(¤t->mm->mmap_sem); + 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); +out_err: + return err; +} + +static int sdcardfs_getattr(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + struct dentry *lower_dentry; + struct inode *inode; + struct inode *lower_inode; + struct path lower_path; + struct dentry *parent; + + parent = dget_parent(dentry); + if(!check_caller_access_to_name(d_inode(parent), 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); + dput(parent); + return -EACCES; + } + dput(parent); + + inode = d_inode(dentry); + + sdcardfs_get_lower_path(dentry, &lower_path); + lower_dentry = lower_path.dentry; + lower_inode = sdcardfs_lower_inode(inode); + + + sdcardfs_copy_and_fix_attrs(inode, lower_inode); + fsstack_copy_inode_size(inode, lower_inode); + + + generic_fillattr(inode, stat); + sdcardfs_put_lower_path(dentry, &lower_path); + return 0; +} + +const struct inode_operations sdcardfs_symlink_iops = { + .permission = sdcardfs_permission, + .setattr = 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, +#if 0 + .permission = sdcardfs_permission, +#endif + .unlink = sdcardfs_unlink, + .mkdir = sdcardfs_mkdir, + .rmdir = sdcardfs_rmdir, + .rename = sdcardfs_rename, + .setattr = sdcardfs_setattr, + .getattr = sdcardfs_getattr, + /* XXX Following operations are implemented, + * but FUSE(sdcard) or FAT does not support them + * These methods are *NOT* perfectly tested. + .symlink = sdcardfs_symlink, + .link = sdcardfs_link, + .mknod = sdcardfs_mknod, + */ +}; + +const struct inode_operations sdcardfs_main_iops = { + .permission = sdcardfs_permission, + .setattr = sdcardfs_setattr, + .getattr = sdcardfs_getattr, +}; diff --git a/fs/sdcardfs/lookup.c b/fs/sdcardfs/lookup.c new file mode 100644 index 000000000000..a01b06a514fd --- /dev/null +++ b/fs/sdcardfs/lookup.c @@ -0,0 +1,384 @@ +/* + * 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) +{ + if (sdcardfs_dentry_cachep) + kmem_cache_destroy(sdcardfs_dentry_cachep); +} + +void free_dentry_private_data(struct dentry *dentry) +{ + if (!dentry || !dentry->d_fsdata) + return; + 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)->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 */ + int err; + + 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) { + err = -EACCES; + iput(lower_inode); + return ERR_PTR(err); + } + /* if found a cached inode, then just return it */ + if (!(inode->i_state & I_NEW)) + return inode; + + /* initialize new inode */ + info = SDCARDFS_I(inode); + + inode->i_ino = lower_inode->i_ino; + if (!igrab(lower_inode)) { + err = -ESTALE; + return ERR_PTR(err); + } + sdcardfs_set_lower_inode(inode, lower_inode); + + inode->i_version++; + + /* 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; +} + +/* + * Connect a 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) +{ + int err = 0; + struct inode *inode; + struct inode *lower_inode; + struct super_block *lower_sb; + + lower_inode = lower_path->dentry->d_inode; + 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) { + err = -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)) { + err = PTR_ERR(inode); + goto out; + } + + d_add(dentry, inode); + update_derived_permission_lock(dentry); +out: + return err; +} + +/* + * 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 char *name; + struct path lower_path; + struct qstr this; + 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.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, 0, + &lower_path); + + /* 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. */ + printk(KERN_INFO "sdcardfs: base obbpath is not available\n"); + sdcardfs_put_reset_orig_path(dentry); + goto out; + } + } + + sdcardfs_set_lower_path(dentry, &lower_path); + err = sdcardfs_interpose(dentry, dentry->d_sb, &lower_path, id); + if (err) /* 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 */ + this.name = name; + this.len = strlen(name); + this.hash = full_name_hash(this.name, this.len); + lower_dentry = d_lookup(lower_dir_dentry, &this); + if (lower_dentry) + goto setup_lower; + + lower_dentry = d_alloc(lower_dir_dentry, &this); + if (!lower_dentry) { + err = -ENOMEM; + goto out; + } + d_add(lower_dentry, NULL); /* instantiate and hash */ + +setup_lower: + 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: + return ERR_PTR(err); +} + +/* + * On success: + * fills dentry object appropriate values and returns NULL. + * On fail (== error) + * returns error ptr + * + * @dir : Parent inode. It is locked (dir->i_mutex) + * @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(parent->d_inode, dentry->d_name.name)) { + ret = ERR_PTR(-EACCES); + 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); + goto out_err; + } + + /* save current_cred and override it */ + OVERRIDE_CRED_PTR(SDCARDFS_SB(dir->i_sb), saved_cred); + + 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)->userid); + if (IS_ERR(ret)) + { + goto out; + } + if (ret) + dentry = ret; + if (dentry->d_inode) { + fsstack_copy_attr_times(dentry->d_inode, + sdcardfs_lower_inode(dentry->d_inode)); + /* get drived permission */ + mutex_lock(&dentry->d_inode->i_mutex); + get_derived_permission(parent, dentry); + fix_derived_permission(dentry->d_inode); + mutex_unlock(&dentry->d_inode->i_mutex); + } + /* update parent directory's atime */ + fsstack_copy_attr_atime(parent->d_inode, + sdcardfs_lower_inode(parent->d_inode)); + +out: + sdcardfs_put_lower_path(parent, &lower_parent_path); + REVERT_CRED(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 000000000000..a6522286d731 --- /dev/null +++ b/fs/sdcardfs/main.c @@ -0,0 +1,402 @@ +/* + * 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_lower_fs, + Opt_mask, + Opt_multiuser, // May need? + Opt_userid, + Opt_reserved_mb, + 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_reserved_mb, "reserved_mb=%u"}, + {Opt_err, NULL} +}; + +static int parse_options(struct super_block *sb, char *options, int silent, + int *debug, 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; + opts->mask = 0; + opts->multiuser = false; + opts->fs_user_id = 0; + opts->gid = 0; + /* by default, 0MB is reserved */ + opts->reserved_mb = 0; + + *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; + opts->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; + opts->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; + /* unknown option */ + default: + if (!silent) { + printk( KERN_ERR "Unrecognized mount option \"%s\" " + "or missing value", p); + } + return -EINVAL; + } + } + + if (*debug) { + printk( KERN_INFO "sdcardfs : options - debug:%d\n", *debug); + printk( KERN_INFO "sdcardfs : options - uid:%d\n", + opts->fs_low_uid); + printk( KERN_INFO "sdcardfs : options - gid:%d\n", + opts->fs_low_gid); + } + + 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); +LIST_HEAD(sdcardfs_super_list); +EXPORT_SYMBOL_GPL(sdcardfs_super_list_lock); +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 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 inode *inode; + + printk(KERN_INFO "sdcardfs version 2.0\n"); + + if (!dev_name) { + printk(KERN_ERR + "sdcardfs: read_super: missing dev_name argument\n"); + err = -EINVAL; + goto out; + } + + printk(KERN_INFO "sdcardfs: dev_name -> %s\n", dev_name); + printk(KERN_INFO "sdcardfs: options -> %s\n", (char *)raw_data); + + /* parse lower path */ + err = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, + &lower_path); + if (err) { + printk(KERN_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)) { + printk(KERN_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, &sb_info->options); + if (err) { + printk(KERN_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); + + /* 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, lower_path.dentry->d_inode, 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_iput; + } + 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(sb->s_root->d_inode, PERM_PRE_ROOT, sb_info->options.fs_user_id, AID_ROOT, false); + snprintf(sb_info->obbpath_s, PATH_MAX, "%s/obb", dev_name); + /*err = prepare_dir(sb_info->obbpath_s, + sb_info->options.fs_low_uid, + sb_info->options.fs_low_gid, 00755);*/ + } else { + setup_derived_state(sb->s_root->d_inode, PERM_ROOT, sb_info->options.fs_low_uid, AID_ROOT, false); + snprintf(sb_info->obbpath_s, PATH_MAX, "%s/Android/obb", dev_name); + } + fix_derived_permission(sb->s_root->d_inode); + sb_info->sb = sb; + list_add(&sb_info->list, &sdcardfs_super_list); + mutex_unlock(&sdcardfs_super_list_lock); + + if (!silent) + printk(KERN_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); +out_iput: + iput(inode); +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; +} + +/* A feature which supports mount_nodev() with options */ +static struct dentry *mount_nodev_with_options(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data, + int (*fill_super)(struct super_block *, const char *, void *, int)) + +{ + int error; + struct super_block *s = sget(fs_type, NULL, set_anon_super, flags, NULL); + + if (IS_ERR(s)) + return ERR_CAST(s); + + s->s_flags = flags; + + error = fill_super(s, dev_name, data, flags & MS_SILENT ? 1 : 0); + if (error) { + deactivate_locked_super(s); + return ERR_PTR(error); + } + s->s_flags |= MS_ACTIVE; + return dget(s->s_root); +} + +struct dentry *sdcardfs_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *raw_data) +{ + /* + * dev_name is a lower_path_name, + * raw_data is a option string. + */ + return mount_nodev_with_options(fs_type, flags, dev_name, + raw_data, sdcardfs_read_super); +} + +void sdcardfs_kill_sb(struct super_block *sb) { + struct sdcardfs_sb_info *sbi; + if (sb->s_magic == SDCARDFS_SUPER_MAGIC) { + sbi = SDCARDFS_SB(sb); + mutex_lock(&sdcardfs_super_list_lock); + list_del(&sbi->list); + mutex_unlock(&sdcardfs_super_list_lock); + } + generic_shutdown_super(sb); +} + +static struct file_system_type sdcardfs_fs_type = { + .owner = THIS_MODULE, + .name = SDCARDFS_NAME, + .mount = sdcardfs_mount, + .kill_sb = sdcardfs_kill_sb, + .fs_flags = 0, +}; + +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"); +} + +MODULE_AUTHOR("Erez Zadok, Filesystems and Storage Lab, Stony Brook University" + " (http://www.fsl.cs.sunysb.edu/)"); +MODULE_DESCRIPTION("Wrapfs " SDCARDFS_VERSION + " (http://wrapfs.filesystems.org/)"); +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 000000000000..e21f64675a80 --- /dev/null +++ b/fs/sdcardfs/mmap.c @@ -0,0 +1,81 @@ +/* + * 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_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 ssize_t sdcardfs_direct_IO(struct kiocb *iocb, + struct iov_iter *iter, loff_t pos) +{ + /* + * This function returns zero on purpose in order to support direct IO. + * __dentry_open checks a_ops->direct_IO and returns EINVAL if it is null. + * + * However, this function won't be called by certain file operations + * including generic fs functions. * reads and writes are delivered to + * the lower file systems and the direct IOs will be handled by them. + * + * NOTE: exceptionally, on the recent kernels (since Linux 3.8.x), + * swap_writepage invokes this function directly. + */ + printk(KERN_INFO "%s, operation is not supported\n", __func__); + return 0; +} + +/* + * XXX: the default address_space_ops for sdcardfs is empty. We cannot set + * our inode->i_mapping->a_ops to NULL because too many code paths expect + * the a_ops vector to be non-NULL. + */ +const struct address_space_operations sdcardfs_aops = { + /* empty on purpose */ + .direct_IO = sdcardfs_direct_IO, +}; + +const struct vm_operations_struct sdcardfs_vm_ops = { + .fault = sdcardfs_fault, +}; diff --git a/fs/sdcardfs/multiuser.h b/fs/sdcardfs/multiuser.h new file mode 100644 index 000000000000..923ba101dfa9 --- /dev/null +++ b/fs/sdcardfs/multiuser.h @@ -0,0 +1,37 @@ +/* + * 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 MULTIUSER_APP_PER_USER_RANGE 100000 + +typedef uid_t userid_t; +typedef uid_t appid_t; + +static inline userid_t multiuser_get_user_id(uid_t uid) { + return uid / MULTIUSER_APP_PER_USER_RANGE; +} + +static inline appid_t multiuser_get_app_id(uid_t uid) { + return uid % MULTIUSER_APP_PER_USER_RANGE; +} + +static inline uid_t multiuser_get_uid(userid_t userId, appid_t appId) { + return userId * MULTIUSER_APP_PER_USER_RANGE + (appId % MULTIUSER_APP_PER_USER_RANGE); +} + diff --git a/fs/sdcardfs/packagelist.c b/fs/sdcardfs/packagelist.c new file mode 100644 index 000000000000..10f0d6be718b --- /dev/null +++ b/fs/sdcardfs/packagelist.c @@ -0,0 +1,437 @@ +/* + * 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/delay.h> + + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include <linux/configfs.h> + +#define STRING_BUF_SIZE (512) + +struct hashtable_entry { + struct hlist_node hlist; + void *key; + unsigned int value; +}; + +struct sb_list { + struct super_block *sb; + struct list_head list; +}; + +struct packagelist_data { + DECLARE_HASHTABLE(package_to_appid,8); + struct mutex hashtable_lock; + +}; + +static struct packagelist_data *pkgl_data_all; + +static struct kmem_cache *hashtable_entry_cachep; + +static unsigned int str_hash(const char *key) { + int i; + unsigned int h = strlen(key); + char *data = (char *)key; + + for (i = 0; i < strlen(key); i++) { + h = h * 31 + *data; + data++; + } + return h; +} + +appid_t get_appid(void *pkgl_id, const char *app_name) +{ + struct packagelist_data *pkgl_dat = pkgl_data_all; + struct hashtable_entry *hash_cur; + unsigned int hash = str_hash(app_name); + appid_t ret_id; + + mutex_lock(&pkgl_dat->hashtable_lock); + hash_for_each_possible(pkgl_dat->package_to_appid, hash_cur, hlist, hash) { + if (!strcasecmp(app_name, hash_cur->key)) { + ret_id = (appid_t)hash_cur->value; + mutex_unlock(&pkgl_dat->hashtable_lock); + return ret_id; + } + } + mutex_unlock(&pkgl_dat->hashtable_lock); + return 0; +} + +/* 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 char* name) { + + /* Always block security-sensitive files at root */ + if (parent_node && SDCARDFS_I(parent_node)->perm == PERM_ROOT) { + if (!strcasecmp(name, "autorun.inf") + || !strcasecmp(name, ".android_secure") + || !strcasecmp(name, "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; +} + +/* This function is used when file opening. The open flags must be + * checked before calling check_caller_access_to_name() */ +int open_flags_to_access_mode(int open_flags) { + if((open_flags & O_ACCMODE) == O_RDONLY) { + return 0; /* R_OK */ + } else if ((open_flags & O_ACCMODE) == O_WRONLY) { + return 1; /* W_OK */ + } else { + /* Probably O_RDRW, but treat as default to be safe */ + return 1; /* R_OK | W_OK */ + } +} + +static int insert_str_to_int_lock(struct packagelist_data *pkgl_dat, char *key, + unsigned int value) +{ + struct hashtable_entry *hash_cur; + struct hashtable_entry *new_entry; + unsigned int hash = str_hash(key); + + hash_for_each_possible(pkgl_dat->package_to_appid, hash_cur, hlist, hash) { + if (!strcasecmp(key, hash_cur->key)) { + hash_cur->value = value; + return 0; + } + } + new_entry = kmem_cache_alloc(hashtable_entry_cachep, GFP_KERNEL); + if (!new_entry) + return -ENOMEM; + new_entry->key = kstrdup(key, GFP_KERNEL); + new_entry->value = value; + hash_add(pkgl_dat->package_to_appid, &new_entry->hlist, hash); + return 0; +} + +static void fixup_perms(struct super_block *sb) { + if (sb && sb->s_magic == SDCARDFS_SUPER_MAGIC) { + mutex_lock(&sb->s_root->d_inode->i_mutex); + get_derive_permissions_recursive(sb->s_root); + mutex_unlock(&sb->s_root->d_inode->i_mutex); + } +} + +static int insert_str_to_int(struct packagelist_data *pkgl_dat, char *key, + unsigned int value) { + int ret; + struct sdcardfs_sb_info *sbinfo; + mutex_lock(&sdcardfs_super_list_lock); + mutex_lock(&pkgl_dat->hashtable_lock); + ret = insert_str_to_int_lock(pkgl_dat, key, value); + mutex_unlock(&pkgl_dat->hashtable_lock); + + list_for_each_entry(sbinfo, &sdcardfs_super_list, list) { + if (sbinfo) { + fixup_perms(sbinfo->sb); + } + } + mutex_unlock(&sdcardfs_super_list_lock); + return ret; +} + +static void remove_str_to_int_lock(struct hashtable_entry *h_entry) { + kfree(h_entry->key); + hash_del(&h_entry->hlist); + kmem_cache_free(hashtable_entry_cachep, h_entry); +} + +static void remove_str_to_int(struct packagelist_data *pkgl_dat, const char *key) +{ + struct sdcardfs_sb_info *sbinfo; + struct hashtable_entry *hash_cur; + unsigned int hash = str_hash(key); + mutex_lock(&sdcardfs_super_list_lock); + mutex_lock(&pkgl_dat->hashtable_lock); + hash_for_each_possible(pkgl_dat->package_to_appid, hash_cur, hlist, hash) { + if (!strcasecmp(key, hash_cur->key)) { + remove_str_to_int_lock(hash_cur); + break; + } + } + mutex_unlock(&pkgl_dat->hashtable_lock); + list_for_each_entry(sbinfo, &sdcardfs_super_list, list) { + if (sbinfo) { + fixup_perms(sbinfo->sb); + } + } + mutex_unlock(&sdcardfs_super_list_lock); + return; +} + +static void remove_all_hashentrys(struct packagelist_data *pkgl_dat) +{ + struct hashtable_entry *hash_cur; + struct hlist_node *h_t; + int i; + mutex_lock(&pkgl_dat->hashtable_lock); + hash_for_each_safe(pkgl_dat->package_to_appid, i, h_t, hash_cur, hlist) + remove_str_to_int_lock(hash_cur); + mutex_unlock(&pkgl_dat->hashtable_lock); + hash_init(pkgl_dat->package_to_appid); +} + +static struct packagelist_data * packagelist_create(void) +{ + struct packagelist_data *pkgl_dat; + + pkgl_dat = kmalloc(sizeof(*pkgl_dat), GFP_KERNEL | __GFP_ZERO); + if (!pkgl_dat) { + printk(KERN_ERR "sdcardfs: Failed to create hash\n"); + return ERR_PTR(-ENOMEM); + } + + mutex_init(&pkgl_dat->hashtable_lock); + hash_init(pkgl_dat->package_to_appid); + + return pkgl_dat; +} + +static void packagelist_destroy(struct packagelist_data *pkgl_dat) +{ + remove_all_hashentrys(pkgl_dat); + printk(KERN_INFO "sdcardfs: destroyed packagelist pkgld\n"); + kfree(pkgl_dat); +} + +struct package_appid { + struct config_item item; + int add_pid; +}; + +static inline struct package_appid *to_package_appid(struct config_item *item) +{ + return item ? container_of(item, struct package_appid, item) : NULL; +} + +static ssize_t package_appid_attr_show(struct config_item *item, + char *page) +{ + ssize_t count; + count = sprintf(page, "%d\n", get_appid(pkgl_data_all, item->ci_name)); + return count; +} + +static ssize_t package_appid_attr_store(struct config_item *item, + const char *page, size_t count) +{ + struct package_appid *package_appid = to_package_appid(item); + unsigned long tmp; + char *p = (char *) page; + int ret; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > INT_MAX) + return -ERANGE; + ret = insert_str_to_int(pkgl_data_all, item->ci_name, (unsigned int)tmp); + package_appid->add_pid = tmp; + if (ret) + return ret; + + return count; +} + +static struct configfs_attribute package_appid_attr_add_pid = { + .ca_owner = THIS_MODULE, + .ca_name = "appid", + .ca_mode = S_IRUGO | S_IWUGO, + .show = package_appid_attr_show, + .store = package_appid_attr_store, +}; + +static struct configfs_attribute *package_appid_attrs[] = { + &package_appid_attr_add_pid, + NULL, +}; + +static void package_appid_release(struct config_item *item) +{ + printk(KERN_INFO "sdcardfs: removing %s\n", item->ci_dentry->d_name.name); + /* item->ci_name is freed already, so we rely on the dentry */ + remove_str_to_int(pkgl_data_all, item->ci_dentry->d_name.name); + kfree(to_package_appid(item)); +} + +static struct configfs_item_operations package_appid_item_ops = { + .release = package_appid_release, +}; + +static struct config_item_type package_appid_type = { + .ct_item_ops = &package_appid_item_ops, + .ct_attrs = package_appid_attrs, + .ct_owner = THIS_MODULE, +}; + + +struct sdcardfs_packages { + struct config_group group; +}; + +static inline struct sdcardfs_packages *to_sdcardfs_packages(struct config_item *item) +{ + return item ? container_of(to_config_group(item), struct sdcardfs_packages, group) : NULL; +} + +static struct config_item *sdcardfs_packages_make_item(struct config_group *group, const char *name) +{ + struct package_appid *package_appid; + + package_appid = kzalloc(sizeof(struct package_appid), GFP_KERNEL); + if (!package_appid) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&package_appid->item, name, + &package_appid_type); + + package_appid->add_pid = 0; + + return &package_appid->item; +} + +static ssize_t packages_attr_show(struct config_item *item, + char *page) +{ + struct hashtable_entry *hash_cur; + struct hlist_node *h_t; + int i; + int count = 0; + mutex_lock(&pkgl_data_all->hashtable_lock); + hash_for_each_safe(pkgl_data_all->package_to_appid, i, h_t, hash_cur, hlist) + count += snprintf(page + count, PAGE_SIZE - count, "%s %d\n", (char *)hash_cur->key, hash_cur->value); + mutex_unlock(&pkgl_data_all->hashtable_lock); + + + return count; +} + +static struct configfs_attribute sdcardfs_packages_attr_description = { + .ca_owner = THIS_MODULE, + .ca_name = "packages_gid.list", + .ca_mode = S_IRUGO, + .show = packages_attr_show, +}; + +static struct configfs_attribute *sdcardfs_packages_attrs[] = { + &sdcardfs_packages_attr_description, + NULL, +}; + +static void sdcardfs_packages_release(struct config_item *item) +{ + + printk(KERN_INFO "sdcardfs: destroyed something?\n"); + kfree(to_sdcardfs_packages(item)); +} + +static struct configfs_item_operations sdcardfs_packages_item_ops = { + .release = sdcardfs_packages_release, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static struct configfs_group_operations sdcardfs_packages_group_ops = { + .make_item = sdcardfs_packages_make_item, +}; + +static struct config_item_type sdcardfs_packages_type = { + .ct_item_ops = &sdcardfs_packages_item_ops, + .ct_group_ops = &sdcardfs_packages_group_ops, + .ct_attrs = sdcardfs_packages_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem sdcardfs_packages_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "sdcardfs", + .ci_type = &sdcardfs_packages_type, + }, + }, +}; + +static int configfs_sdcardfs_init(void) +{ + int ret; + struct configfs_subsystem *subsys = &sdcardfs_packages_subsys; + + config_group_init(&subsys->su_group); + mutex_init(&subsys->su_mutex); + ret = configfs_register_subsystem(subsys); + if (ret) { + printk(KERN_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_subsys); +} + +int packagelist_init(void) +{ + hashtable_entry_cachep = + kmem_cache_create("packagelist_hashtable_entry", + sizeof(struct hashtable_entry), 0, 0, NULL); + if (!hashtable_entry_cachep) { + printk(KERN_ERR "sdcardfs: failed creating pkgl_hashtable entry slab cache\n"); + return -ENOMEM; + } + + pkgl_data_all = packagelist_create(); + configfs_sdcardfs_init(); + return 0; +} + +void packagelist_exit(void) +{ + configfs_sdcardfs_exit(); + packagelist_destroy(pkgl_data_all); + if (hashtable_entry_cachep) + kmem_cache_destroy(hashtable_entry_cachep); +} diff --git a/fs/sdcardfs/sdcardfs.h b/fs/sdcardfs/sdcardfs.h new file mode 100644 index 000000000000..f111f898b630 --- /dev/null +++ b/fs/sdcardfs/sdcardfs.h @@ -0,0 +1,530 @@ +/* + * 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/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 "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 printk(KERN_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_PACKAGE_INFO 1027 + +#define fix_derived_permission(x) \ + do { \ + (x)->i_uid = make_kuid(&init_user_ns, SDCARDFS_I(x)->d_uid); \ + (x)->i_gid = make_kgid(&init_user_ns, get_gid(SDCARDFS_I(x))); \ + (x)->i_mode = ((x)->i_mode & S_IFMT) | get_mode(SDCARDFS_I(x));\ + } while (0) + + +/* OVERRIDE_CRED() and REVERT_CRED() + * OVERRID_CRED() + * backup original task->cred + * and modifies task->cred->fsuid/fsgid to specified value. + * REVERT_CRED() + * restore original task->cred->fsuid/fsgid. + * These two macro should be used in pair, and OVERRIDE_CRED() should be + * placed at the beginning of a function, right after variable declaration. + */ +#define OVERRIDE_CRED(sdcardfs_sbi, saved_cred) \ + saved_cred = override_fsids(sdcardfs_sbi); \ + if (!saved_cred) { return -ENOMEM; } + +#define OVERRIDE_CRED_PTR(sdcardfs_sbi, saved_cred) \ + saved_cred = override_fsids(sdcardfs_sbi); \ + if (!saved_cred) { return ERR_PTR(-ENOMEM); } + +#define REVERT_CRED(saved_cred) revert_fsids(saved_cred) + +#define DEBUG_CRED() \ + printk("KAKJAGI: %s:%d fsuid %d fsgid %d\n", \ + __FUNCTION__, __LINE__, \ + (int)current->cred->fsuid, \ + (int)current->cred->fsgid); + +/* 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, +} perm_t; + +struct sdcardfs_sb_info; +struct sdcardfs_mount_options; + +/* Do not directly use this function. Use OVERRIDE_CRED() instead. */ +const struct cred * override_fsids(struct sdcardfs_sb_info* sbi); +/* 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; +}; + +/* sdcardfs inode data in memory */ +struct sdcardfs_inode_info { + struct inode *lower_inode; + /* state derived based on current position in hierachy */ + perm_t perm; + userid_t userid; + uid_t d_uid; + bool under_android; + + 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; + gid_t gid; + mode_t mask; + bool multiuser; + unsigned int reserved_mb; +}; + +/* 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 int get_gid(struct sdcardfs_inode_info *info) { + struct sdcardfs_sb_info *sb_info = SDCARDFS_SB(info->vfs_inode.i_sb); + if (sb_info->options.gid == AID_SDCARD_RW) { + /* 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(info->userid, sb_info->options.gid); + } +} +static inline int get_mode(struct sdcardfs_inode_info *info) { + int owner_mode; + int filtered_mode; + struct sdcardfs_sb_info *sb_info = SDCARDFS_SB(info->vfs_inode.i_sb); + int visible_mode = 0775 & ~sb_info->options.mask; + + if (info->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 (info->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 (sb_info->options.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(void *pkgl_id, const char *app_name); +extern int check_caller_access_to_name(struct inode *parent_node, const char* name); +extern int open_flags_to_access_mode(int open_flags); +extern int packagelist_init(void); +extern void packagelist_exit(void); + +/* for derived_perm.c */ +extern void setup_derived_state(struct inode *inode, perm_t perm, + userid_t userid, uid_t uid, bool under_android); +extern void get_derived_permission(struct dentry *parent, struct dentry *dentry); +extern void get_derived_permission_new(struct dentry *parent, struct dentry *dentry, struct dentry *newdentry); +extern void get_derive_permissions_recursive(struct dentry *parent); + +extern void update_derived_permission_lock(struct dentry *dentry); +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); + mutex_lock_nested(&d_inode(dir)->i_mutex, I_MUTEX_PARENT); + return dir; +} + +static inline void unlock_dir(struct dentry *dir) +{ + mutex_unlock(&d_inode(dir)->i_mutex); + 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_mkdir(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; + mutex_lock(&d_inode(dent)->i_mutex); + notify_change(dent, &attrs, NULL); + mutex_unlock(&d_inode(dent)->i_mutex); + +out_dput: + dput(dent); + +out_unlock: + /* parent dentry locked by lookup_create */ + mutex_unlock(&d_inode(parent.dentry)->i_mutex); + 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 */ +static inline void sdcardfs_copy_and_fix_attrs(struct inode *dest, const struct inode *src) +{ + dest->i_mode = (src->i_mode & S_IFMT) | get_mode(SDCARDFS_I(dest)); + dest->i_uid = make_kuid(&init_user_ns, SDCARDFS_I(dest)->d_uid); + dest->i_gid = make_kgid(&init_user_ns, get_gid(SDCARDFS_I(dest))); + 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); +} +#endif /* not _SDCARDFS_H_ */ diff --git a/fs/sdcardfs/super.c b/fs/sdcardfs/super.c new file mode 100644 index 000000000000..1d6490128c99 --- /dev/null +++ b/fs/sdcardfs/super.c @@ -0,0 +1,222 @@ +/* + * 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; + +/* 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) { + printk(KERN_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) { + printk(KERN_ERR + "sdcardfs: remount flags 0x%x unsupported\n", *flags); + err = -EINVAL; + } + + return err; +} + +/* + * 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); + 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; + + 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)); + + i->vfs_inode.i_version = 1; + return &i->vfs_inode; +} + +static void sdcardfs_destroy_inode(struct inode *inode) +{ + kmem_cache_free(sdcardfs_inode_cachep, SDCARDFS_I(inode)); +} + +/* 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) +{ + int err = 0; + + sdcardfs_inode_cachep = + kmem_cache_create("sdcardfs_inode_cache", + sizeof(struct sdcardfs_inode_info), 0, + SLAB_RECLAIM_ACCOUNT, init_once); + if (!sdcardfs_inode_cachep) + err = -ENOMEM; + return err; +} + +/* sdcardfs inode cache destructor */ +void sdcardfs_destroy_inode_cache(void) +{ + if (sdcardfs_inode_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 seq_file *m, struct dentry *root) +{ + struct sdcardfs_sb_info *sbi = SDCARDFS_SB(root->d_sb); + struct sdcardfs_mount_options *opts = &sbi->options; + + if (opts->fs_low_uid != 0) + seq_printf(m, ",uid=%u", opts->fs_low_uid); + if (opts->fs_low_gid != 0) + seq_printf(m, ",gid=%u", opts->fs_low_gid); + + if (opts->multiuser) + seq_printf(m, ",multiuser"); + + if (opts->reserved_mb != 0) + seq_printf(m, ",reserved=%uMB", opts->reserved_mb); + + return 0; +}; + +const struct super_operations sdcardfs_sops = { + .put_super = sdcardfs_put_super, + .statfs = sdcardfs_statfs, + .remount_fs = sdcardfs_remount_fs, + .evict_inode = sdcardfs_evict_inode, + .umount_begin = sdcardfs_umount_begin, + .show_options = sdcardfs_show_options, + .alloc_inode = sdcardfs_alloc_inode, + .destroy_inode = sdcardfs_destroy_inode, + .drop_inode = generic_delete_inode, +}; |