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platform_system_core/sdcard/sdcard.c
Ken Sumrall 2fd72cc221 Raise the max file open limit in sdcard 
The default is 1024 files, and in some testing, the limit has been
hit.  This raises the limit to 8192.  Going higher starts to cause
performance issues (I started to notice that around 16K open files
in my testing) as sdcard does linear searches.  If a higher max
is needed, then the sdcard daemon will need some optimizations.

Bug: 7442187

Change-Id: I7aba7f4556ed70651f36244294a6756f3d6b8963
2013-02-11 15:42:22 -08:00

1367 lines
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/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/uio.h>
#include <dirent.h>
#include <limits.h>
#include <ctype.h>
#include <pthread.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <private/android_filesystem_config.h>
#include "fuse.h"
/* README
*
* What is this?
*
* sdcard is a program that uses FUSE to emulate FAT-on-sdcard style
* directory permissions (all files are given fixed owner, group, and
* permissions at creation, owner, group, and permissions are not
* changeable, symlinks and hardlinks are not createable, etc.
*
* See usage() for command line options.
*
* It must be run as root, but will drop to requested UID/GID as soon as it
* mounts a filesystem. It will refuse to run if requested UID/GID are zero.
*
* Things I believe to be true:
*
* - ops that return a fuse_entry (LOOKUP, MKNOD, MKDIR, LINK, SYMLINK,
* CREAT) must bump that node's refcount
* - don't forget that FORGET can forget multiple references (req->nlookup)
* - if an op that returns a fuse_entry fails writing the reply to the
* kernel, you must rollback the refcount to reflect the reference the
* kernel did not actually acquire
*/
#define FUSE_TRACE 0
#if FUSE_TRACE
#define TRACE(x...) fprintf(stderr,x)
#else
#define TRACE(x...) do {} while (0)
#endif
#define ERROR(x...) fprintf(stderr,x)
#define FUSE_UNKNOWN_INO 0xffffffff
/* Maximum number of bytes to write in one request. */
#define MAX_WRITE (256 * 1024)
/* Maximum number of bytes to read in one request. */
#define MAX_READ (128 * 1024)
/* Largest possible request.
* The request size is bounded by the maximum size of a FUSE_WRITE request because it has
* the largest possible data payload. */
#define MAX_REQUEST_SIZE (sizeof(struct fuse_in_header) + sizeof(struct fuse_write_in) + MAX_WRITE)
/* Default number of threads. */
#define DEFAULT_NUM_THREADS 2
/* Pseudo-error constant used to indicate that no fuse status is needed
* or that a reply has already been written. */
#define NO_STATUS 1
struct handle {
int fd;
};
struct dirhandle {
DIR *d;
};
struct node {
__u32 refcount;
__u64 nid;
__u64 gen;
struct node *next; /* per-dir sibling list */
struct node *child; /* first contained file by this dir */
struct node *parent; /* containing directory */
size_t namelen;
char *name;
/* If non-null, this is the real name of the file in the underlying storage.
* This may differ from the field "name" only by case.
* strlen(actual_name) will always equal strlen(name), so it is safe to use
* namelen for both fields.
*/
char *actual_name;
};
/* Global data structure shared by all fuse handlers. */
struct fuse {
pthread_mutex_t lock;
__u64 next_generation;
int fd;
struct node root;
char rootpath[PATH_MAX];
};
/* Private data used by a single fuse handler. */
struct fuse_handler {
struct fuse* fuse;
int token;
/* To save memory, we never use the contents of the request buffer and the read
* buffer at the same time. This allows us to share the underlying storage. */
union {
__u8 request_buffer[MAX_REQUEST_SIZE];
__u8 read_buffer[MAX_READ];
};
};
static inline void *id_to_ptr(__u64 nid)
{
return (void *) (uintptr_t) nid;
}
static inline __u64 ptr_to_id(void *ptr)
{
return (__u64) (uintptr_t) ptr;
}
static void acquire_node_locked(struct node* node)
{
node->refcount++;
TRACE("ACQUIRE %p (%s) rc=%d\n", node, node->name, node->refcount);
}
static void remove_node_from_parent_locked(struct node* node);
static void release_node_locked(struct node* node)
{
TRACE("RELEASE %p (%s) rc=%d\n", node, node->name, node->refcount);
if (node->refcount > 0) {
node->refcount--;
if (!node->refcount) {
TRACE("DESTROY %p (%s)\n", node, node->name);
remove_node_from_parent_locked(node);
/* TODO: remove debugging - poison memory */
memset(node->name, 0xef, node->namelen);
free(node->name);
free(node->actual_name);
memset(node, 0xfc, sizeof(*node));
free(node);
}
} else {
ERROR("Zero refcnt %p\n", node);
}
}
static void add_node_to_parent_locked(struct node *node, struct node *parent) {
node->parent = parent;
node->next = parent->child;
parent->child = node;
acquire_node_locked(parent);
}
static void remove_node_from_parent_locked(struct node* node)
{
if (node->parent) {
if (node->parent->child == node) {
node->parent->child = node->parent->child->next;
} else {
struct node *node2;
node2 = node->parent->child;
while (node2->next != node)
node2 = node2->next;
node2->next = node->next;
}
release_node_locked(node->parent);
node->parent = NULL;
node->next = NULL;
}
}
/* Gets the absolute path to a node into the provided buffer.
*
* Populates 'buf' with the path and returns the length of the path on success,
* or returns -1 if the path is too long for the provided buffer.
*/
static ssize_t get_node_path_locked(struct node* node, char* buf, size_t bufsize)
{
size_t namelen = node->namelen;
if (bufsize < namelen + 1) {
return -1;
}
ssize_t pathlen = 0;
if (node->parent) {
pathlen = get_node_path_locked(node->parent, buf, bufsize - namelen - 2);
if (pathlen < 0) {
return -1;
}
buf[pathlen++] = '/';
}
const char* name = node->actual_name ? node->actual_name : node->name;
memcpy(buf + pathlen, name, namelen + 1); /* include trailing \0 */
return pathlen + namelen;
}
/* Finds the absolute path of a file within a given directory.
* Performs a case-insensitive search for the file and sets the buffer to the path
* of the first matching file. If 'search' is zero or if no match is found, sets
* the buffer to the path that the file would have, assuming the name were case-sensitive.
*
* Populates 'buf' with the path and returns the actual name (within 'buf') on success,
* or returns NULL if the path is too long for the provided buffer.
*/
static char* find_file_within(const char* path, const char* name,
char* buf, size_t bufsize, int search)
{
size_t pathlen = strlen(path);
size_t namelen = strlen(name);
size_t childlen = pathlen + namelen + 1;
char* actual;
if (bufsize <= childlen) {
return NULL;
}
memcpy(buf, path, pathlen);
buf[pathlen] = '/';
actual = buf + pathlen + 1;
memcpy(actual, name, namelen + 1);
if (search && access(buf, F_OK)) {
struct dirent* entry;
DIR* dir = opendir(path);
if (!dir) {
ERROR("opendir %s failed: %s", path, strerror(errno));
return actual;
}
while ((entry = readdir(dir))) {
if (!strcasecmp(entry->d_name, name)) {
/* we have a match - replace the name, don't need to copy the null again */
memcpy(actual, entry->d_name, namelen);
break;
}
}
closedir(dir);
}
return actual;
}
static void attr_from_stat(struct fuse_attr *attr, const struct stat *s, __u64 nid)
{
attr->ino = nid;
attr->size = s->st_size;
attr->blocks = s->st_blocks;
attr->atime = s->st_atime;
attr->mtime = s->st_mtime;
attr->ctime = s->st_ctime;
attr->atimensec = s->st_atime_nsec;
attr->mtimensec = s->st_mtime_nsec;
attr->ctimensec = s->st_ctime_nsec;
attr->mode = s->st_mode;
attr->nlink = s->st_nlink;
/* force permissions to something reasonable:
* world readable
* writable by the sdcard group
*/
if (attr->mode & 0100) {
attr->mode = (attr->mode & (~0777)) | 0775;
} else {
attr->mode = (attr->mode & (~0777)) | 0664;
}
/* all files owned by root.sdcard */
attr->uid = 0;
attr->gid = AID_SDCARD_RW;
}
struct node *create_node_locked(struct fuse* fuse,
struct node *parent, const char *name, const char* actual_name)
{
struct node *node;
size_t namelen = strlen(name);
node = calloc(1, sizeof(struct node));
if (!node) {
return NULL;
}
node->name = malloc(namelen + 1);
if (!node->name) {
free(node);
return NULL;
}
memcpy(node->name, name, namelen + 1);
if (strcmp(name, actual_name)) {
node->actual_name = malloc(namelen + 1);
if (!node->actual_name) {
free(node->name);
free(node);
return NULL;
}
memcpy(node->actual_name, actual_name, namelen + 1);
}
node->namelen = namelen;
node->nid = ptr_to_id(node);
node->gen = fuse->next_generation++;
acquire_node_locked(node);
add_node_to_parent_locked(node, parent);
return node;
}
static int rename_node_locked(struct node *node, const char *name,
const char* actual_name)
{
size_t namelen = strlen(name);
int need_actual_name = strcmp(name, actual_name);
/* make the storage bigger without actually changing the name
* in case an error occurs part way */
if (namelen > node->namelen) {
char* new_name = realloc(node->name, namelen + 1);
if (!new_name) {
return -ENOMEM;
}
node->name = new_name;
if (need_actual_name && node->actual_name) {
char* new_actual_name = realloc(node->actual_name, namelen + 1);
if (!new_actual_name) {
return -ENOMEM;
}
node->actual_name = new_actual_name;
}
}
/* update the name, taking care to allocate storage before overwriting the old name */
if (need_actual_name) {
if (!node->actual_name) {
node->actual_name = malloc(namelen + 1);
if (!node->actual_name) {
return -ENOMEM;
}
}
memcpy(node->actual_name, actual_name, namelen + 1);
} else {
free(node->actual_name);
node->actual_name = NULL;
}
memcpy(node->name, name, namelen + 1);
node->namelen = namelen;
return 0;
}
static struct node *lookup_node_by_id_locked(struct fuse *fuse, __u64 nid)
{
if (nid == FUSE_ROOT_ID) {
return &fuse->root;
} else {
return id_to_ptr(nid);
}
}
static struct node* lookup_node_and_path_by_id_locked(struct fuse* fuse, __u64 nid,
char* buf, size_t bufsize)
{
struct node* node = lookup_node_by_id_locked(fuse, nid);
if (node && get_node_path_locked(node, buf, bufsize) < 0) {
node = NULL;
}
return node;
}
static struct node *lookup_child_by_name_locked(struct node *node, const char *name)
{
for (node = node->child; node; node = node->next) {
/* use exact string comparison, nodes that differ by case
* must be considered distinct even if they refer to the same
* underlying file as otherwise operations such as "mv x x"
* will not work because the source and target nodes are the same. */
if (!strcmp(name, node->name)) {
return node;
}
}
return 0;
}
static struct node* acquire_or_create_child_locked(
struct fuse* fuse, struct node* parent,
const char* name, const char* actual_name)
{
struct node* child = lookup_child_by_name_locked(parent, name);
if (child) {
acquire_node_locked(child);
} else {
child = create_node_locked(fuse, parent, name, actual_name);
}
return child;
}
static void fuse_init(struct fuse *fuse, int fd, const char *source_path)
{
pthread_mutex_init(&fuse->lock, NULL);
fuse->fd = fd;
fuse->next_generation = 0;
memset(&fuse->root, 0, sizeof(fuse->root));
fuse->root.nid = FUSE_ROOT_ID; /* 1 */
fuse->root.refcount = 2;
fuse->root.namelen = strlen(source_path);
fuse->root.name = strdup(source_path);
}
static void fuse_status(struct fuse *fuse, __u64 unique, int err)
{
struct fuse_out_header hdr;
hdr.len = sizeof(hdr);
hdr.error = err;
hdr.unique = unique;
write(fuse->fd, &hdr, sizeof(hdr));
}
static void fuse_reply(struct fuse *fuse, __u64 unique, void *data, int len)
{
struct fuse_out_header hdr;
struct iovec vec[2];
int res;
hdr.len = len + sizeof(hdr);
hdr.error = 0;
hdr.unique = unique;
vec[0].iov_base = &hdr;
vec[0].iov_len = sizeof(hdr);
vec[1].iov_base = data;
vec[1].iov_len = len;
res = writev(fuse->fd, vec, 2);
if (res < 0) {
ERROR("*** REPLY FAILED *** %d\n", errno);
}
}
static int fuse_reply_entry(struct fuse* fuse, __u64 unique,
struct node* parent, const char* name, const char* actual_name,
const char* path)
{
struct node* node;
struct fuse_entry_out out;
struct stat s;
if (lstat(path, &s) < 0) {
return -errno;
}
pthread_mutex_lock(&fuse->lock);
node = acquire_or_create_child_locked(fuse, parent, name, actual_name);
if (!node) {
pthread_mutex_unlock(&fuse->lock);
return -ENOMEM;
}
memset(&out, 0, sizeof(out));
attr_from_stat(&out.attr, &s, node->nid);
out.attr_valid = 10;
out.entry_valid = 10;
out.nodeid = node->nid;
out.generation = node->gen;
pthread_mutex_unlock(&fuse->lock);
fuse_reply(fuse, unique, &out, sizeof(out));
return NO_STATUS;
}
static int fuse_reply_attr(struct fuse* fuse, __u64 unique, __u64 nid,
const char* path)
{
struct fuse_attr_out out;
struct stat s;
if (lstat(path, &s) < 0) {
return -errno;
}
memset(&out, 0, sizeof(out));
attr_from_stat(&out.attr, &s, nid);
out.attr_valid = 10;
fuse_reply(fuse, unique, &out, sizeof(out));
return NO_STATUS;
}
static int handle_lookup(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header *hdr, const char* name)
{
struct node* parent_node;
char parent_path[PATH_MAX];
char child_path[PATH_MAX];
const char* actual_name;
pthread_mutex_lock(&fuse->lock);
parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid,
parent_path, sizeof(parent_path));
TRACE("[%d] LOOKUP %s @ %llx (%s)\n", handler->token, name, hdr->nodeid,
parent_node ? parent_node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!parent_node || !(actual_name = find_file_within(parent_path, name,
child_path, sizeof(child_path), 1))) {
return -ENOENT;
}
return fuse_reply_entry(fuse, hdr->unique, parent_node, name, actual_name, child_path);
}
static int handle_forget(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header *hdr, const struct fuse_forget_in *req)
{
struct node* node;
pthread_mutex_lock(&fuse->lock);
node = lookup_node_by_id_locked(fuse, hdr->nodeid);
TRACE("[%d] FORGET #%lld @ %llx (%s)\n", handler->token, req->nlookup,
hdr->nodeid, node ? node->name : "?");
if (node) {
__u64 n = req->nlookup;
while (n--) {
release_node_locked(node);
}
}
pthread_mutex_unlock(&fuse->lock);
return NO_STATUS; /* no reply */
}
static int handle_getattr(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header *hdr, const struct fuse_getattr_in *req)
{
struct node* node;
char path[PATH_MAX];
pthread_mutex_lock(&fuse->lock);
node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path));
TRACE("[%d] GETATTR flags=%x fh=%llx @ %llx (%s)\n", handler->token,
req->getattr_flags, req->fh, hdr->nodeid, node ? node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!node) {
return -ENOENT;
}
return fuse_reply_attr(fuse, hdr->unique, hdr->nodeid, path);
}
static int handle_setattr(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header *hdr, const struct fuse_setattr_in *req)
{
struct node* node;
char path[PATH_MAX];
struct timespec times[2];
pthread_mutex_lock(&fuse->lock);
node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path));
TRACE("[%d] SETATTR fh=%llx valid=%x @ %llx (%s)\n", handler->token,
req->fh, req->valid, hdr->nodeid, node ? node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!node) {
return -ENOENT;
}
/* XXX: incomplete implementation on purpose.
* chmod/chown should NEVER be implemented.*/
if ((req->valid & FATTR_SIZE) && truncate(path, req->size) < 0) {
return -errno;
}
/* Handle changing atime and mtime. If FATTR_ATIME_and FATTR_ATIME_NOW
* are both set, then set it to the current time. Else, set it to the
* time specified in the request. Same goes for mtime. Use utimensat(2)
* as it allows ATIME and MTIME to be changed independently, and has
* nanosecond resolution which fuse also has.
*/
if (req->valid & (FATTR_ATIME | FATTR_MTIME)) {
times[0].tv_nsec = UTIME_OMIT;
times[1].tv_nsec = UTIME_OMIT;
if (req->valid & FATTR_ATIME) {
if (req->valid & FATTR_ATIME_NOW) {
times[0].tv_nsec = UTIME_NOW;
} else {
times[0].tv_sec = req->atime;
times[0].tv_nsec = req->atimensec;
}
}
if (req->valid & FATTR_MTIME) {
if (req->valid & FATTR_MTIME_NOW) {
times[1].tv_nsec = UTIME_NOW;
} else {
times[1].tv_sec = req->mtime;
times[1].tv_nsec = req->mtimensec;
}
}
TRACE("[%d] Calling utimensat on %s with atime %ld, mtime=%ld\n",
handler->token, path, times[0].tv_sec, times[1].tv_sec);
if (utimensat(-1, path, times, 0) < 0) {
return -errno;
}
}
return fuse_reply_attr(fuse, hdr->unique, hdr->nodeid, path);
}
static int handle_mknod(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_mknod_in* req, const char* name)
{
struct node* parent_node;
char parent_path[PATH_MAX];
char child_path[PATH_MAX];
const char* actual_name;
pthread_mutex_lock(&fuse->lock);
parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid,
parent_path, sizeof(parent_path));
TRACE("[%d] MKNOD %s 0%o @ %llx (%s)\n", handler->token,
name, req->mode, hdr->nodeid, parent_node ? parent_node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!parent_node || !(actual_name = find_file_within(parent_path, name,
child_path, sizeof(child_path), 1))) {
return -ENOENT;
}
__u32 mode = (req->mode & (~0777)) | 0664;
if (mknod(child_path, mode, req->rdev) < 0) {
return -errno;
}
return fuse_reply_entry(fuse, hdr->unique, parent_node, name, actual_name, child_path);
}
static int handle_mkdir(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_mkdir_in* req, const char* name)
{
struct node* parent_node;
char parent_path[PATH_MAX];
char child_path[PATH_MAX];
const char* actual_name;
pthread_mutex_lock(&fuse->lock);
parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid,
parent_path, sizeof(parent_path));
TRACE("[%d] MKDIR %s 0%o @ %llx (%s)\n", handler->token,
name, req->mode, hdr->nodeid, parent_node ? parent_node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!parent_node || !(actual_name = find_file_within(parent_path, name,
child_path, sizeof(child_path), 1))) {
return -ENOENT;
}
__u32 mode = (req->mode & (~0777)) | 0775;
if (mkdir(child_path, mode) < 0) {
return -errno;
}
return fuse_reply_entry(fuse, hdr->unique, parent_node, name, actual_name, child_path);
}
static int handle_unlink(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const char* name)
{
struct node* parent_node;
char parent_path[PATH_MAX];
char child_path[PATH_MAX];
pthread_mutex_lock(&fuse->lock);
parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid,
parent_path, sizeof(parent_path));
TRACE("[%d] UNLINK %s @ %llx (%s)\n", handler->token,
name, hdr->nodeid, parent_node ? parent_node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!parent_node || !find_file_within(parent_path, name,
child_path, sizeof(child_path), 1)) {
return -ENOENT;
}
if (unlink(child_path) < 0) {
return -errno;
}
return 0;
}
static int handle_rmdir(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const char* name)
{
struct node* parent_node;
char parent_path[PATH_MAX];
char child_path[PATH_MAX];
pthread_mutex_lock(&fuse->lock);
parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid,
parent_path, sizeof(parent_path));
TRACE("[%d] RMDIR %s @ %llx (%s)\n", handler->token,
name, hdr->nodeid, parent_node ? parent_node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!parent_node || !find_file_within(parent_path, name,
child_path, sizeof(child_path), 1)) {
return -ENOENT;
}
if (rmdir(child_path) < 0) {
return -errno;
}
return 0;
}
static int handle_rename(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_rename_in* req,
const char* old_name, const char* new_name)
{
struct node* old_parent_node;
struct node* new_parent_node;
struct node* child_node;
char old_parent_path[PATH_MAX];
char new_parent_path[PATH_MAX];
char old_child_path[PATH_MAX];
char new_child_path[PATH_MAX];
const char* new_actual_name;
int res;
pthread_mutex_lock(&fuse->lock);
old_parent_node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid,
old_parent_path, sizeof(old_parent_path));
new_parent_node = lookup_node_and_path_by_id_locked(fuse, req->newdir,
new_parent_path, sizeof(new_parent_path));
TRACE("[%d] RENAME %s->%s @ %llx (%s) -> %llx (%s)\n", handler->token,
old_name, new_name,
hdr->nodeid, old_parent_node ? old_parent_node->name : "?",
req->newdir, new_parent_node ? new_parent_node->name : "?");
if (!old_parent_node || !new_parent_node) {
res = -ENOENT;
goto lookup_error;
}
child_node = lookup_child_by_name_locked(old_parent_node, old_name);
if (!child_node || get_node_path_locked(child_node,
old_child_path, sizeof(old_child_path)) < 0) {
res = -ENOENT;
goto lookup_error;
}
acquire_node_locked(child_node);
pthread_mutex_unlock(&fuse->lock);
/* Special case for renaming a file where destination is same path
* differing only by case. In this case we don't want to look for a case
* insensitive match. This allows commands like "mv foo FOO" to work as expected.
*/
int search = old_parent_node != new_parent_node
|| strcasecmp(old_name, new_name);
if (!(new_actual_name = find_file_within(new_parent_path, new_name,
new_child_path, sizeof(new_child_path), search))) {
res = -ENOENT;
goto io_error;
}
TRACE("[%d] RENAME %s->%s\n", handler->token, old_child_path, new_child_path);
res = rename(old_child_path, new_child_path);
if (res < 0) {
res = -errno;
goto io_error;
}
pthread_mutex_lock(&fuse->lock);
res = rename_node_locked(child_node, new_name, new_actual_name);
if (!res) {
remove_node_from_parent_locked(child_node);
add_node_to_parent_locked(child_node, new_parent_node);
}
goto done;
io_error:
pthread_mutex_lock(&fuse->lock);
done:
release_node_locked(child_node);
lookup_error:
pthread_mutex_unlock(&fuse->lock);
return res;
}
static int handle_open(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_open_in* req)
{
struct node* node;
char path[PATH_MAX];
struct fuse_open_out out;
struct handle *h;
pthread_mutex_lock(&fuse->lock);
node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path));
TRACE("[%d] OPEN 0%o @ %llx (%s)\n", handler->token,
req->flags, hdr->nodeid, node ? node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!node) {
return -ENOENT;
}
h = malloc(sizeof(*h));
if (!h) {
return -ENOMEM;
}
TRACE("[%d] OPEN %s\n", handler->token, path);
h->fd = open(path, req->flags);
if (h->fd < 0) {
free(h);
return -errno;
}
out.fh = ptr_to_id(h);
out.open_flags = 0;
out.padding = 0;
fuse_reply(fuse, hdr->unique, &out, sizeof(out));
return NO_STATUS;
}
static int handle_read(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_read_in* req)
{
struct handle *h = id_to_ptr(req->fh);
__u64 unique = hdr->unique;
__u32 size = req->size;
__u64 offset = req->offset;
int res;
/* Don't access any other fields of hdr or req beyond this point, the read buffer
* overlaps the request buffer and will clobber data in the request. This
* saves us 128KB per request handler thread at the cost of this scary comment. */
TRACE("[%d] READ %p(%d) %u@%llu\n", handler->token,
h, h->fd, size, offset);
if (size > sizeof(handler->read_buffer)) {
return -EINVAL;
}
res = pread64(h->fd, handler->read_buffer, size, offset);
if (res < 0) {
return -errno;
}
fuse_reply(fuse, unique, handler->read_buffer, res);
return NO_STATUS;
}
static int handle_write(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_write_in* req,
const void* buffer)
{
struct fuse_write_out out;
struct handle *h = id_to_ptr(req->fh);
int res;
TRACE("[%d] WRITE %p(%d) %u@%llu\n", handler->token,
h, h->fd, req->size, req->offset);
res = pwrite64(h->fd, buffer, req->size, req->offset);
if (res < 0) {
return -errno;
}
out.size = res;
fuse_reply(fuse, hdr->unique, &out, sizeof(out));
return NO_STATUS;
}
static int handle_statfs(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr)
{
char path[PATH_MAX];
struct statfs stat;
struct fuse_statfs_out out;
int res;
pthread_mutex_lock(&fuse->lock);
TRACE("[%d] STATFS\n", handler->token);
res = get_node_path_locked(&fuse->root, path, sizeof(path));
pthread_mutex_unlock(&fuse->lock);
if (res < 0) {
return -ENOENT;
}
if (statfs(fuse->root.name, &stat) < 0) {
return -errno;
}
memset(&out, 0, sizeof(out));
out.st.blocks = stat.f_blocks;
out.st.bfree = stat.f_bfree;
out.st.bavail = stat.f_bavail;
out.st.files = stat.f_files;
out.st.ffree = stat.f_ffree;
out.st.bsize = stat.f_bsize;
out.st.namelen = stat.f_namelen;
out.st.frsize = stat.f_frsize;
fuse_reply(fuse, hdr->unique, &out, sizeof(out));
return NO_STATUS;
}
static int handle_release(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_release_in* req)
{
struct handle *h = id_to_ptr(req->fh);
TRACE("[%d] RELEASE %p(%d)\n", handler->token, h, h->fd);
close(h->fd);
free(h);
return 0;
}
static int handle_fsync(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_fsync_in* req)
{
int is_data_sync = req->fsync_flags & 1;
struct handle *h = id_to_ptr(req->fh);
int res;
TRACE("[%d] FSYNC %p(%d) is_data_sync=%d\n", handler->token,
h, h->fd, is_data_sync);
res = is_data_sync ? fdatasync(h->fd) : fsync(h->fd);
if (res < 0) {
return -errno;
}
return 0;
}
static int handle_flush(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr)
{
TRACE("[%d] FLUSH\n", handler->token);
return 0;
}
static int handle_opendir(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_open_in* req)
{
struct node* node;
char path[PATH_MAX];
struct fuse_open_out out;
struct dirhandle *h;
pthread_mutex_lock(&fuse->lock);
node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid, path, sizeof(path));
TRACE("[%d] OPENDIR @ %llx (%s)\n", handler->token,
hdr->nodeid, node ? node->name : "?");
pthread_mutex_unlock(&fuse->lock);
if (!node) {
return -ENOENT;
}
h = malloc(sizeof(*h));
if (!h) {
return -ENOMEM;
}
TRACE("[%d] OPENDIR %s\n", handler->token, path);
h->d = opendir(path);
if (!h->d) {
free(h);
return -errno;
}
out.fh = ptr_to_id(h);
fuse_reply(fuse, hdr->unique, &out, sizeof(out));
return NO_STATUS;
}
static int handle_readdir(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_read_in* req)
{
char buffer[8192];
struct fuse_dirent *fde = (struct fuse_dirent*) buffer;
struct dirent *de;
struct dirhandle *h = id_to_ptr(req->fh);
TRACE("[%d] READDIR %p\n", handler->token, h);
if (req->offset == 0) {
/* rewinddir() might have been called above us, so rewind here too */
TRACE("[%d] calling rewinddir()\n", handler->token);
rewinddir(h->d);
}
de = readdir(h->d);
if (!de) {
return 0;
}
fde->ino = FUSE_UNKNOWN_INO;
/* increment the offset so we can detect when rewinddir() seeks back to the beginning */
fde->off = req->offset + 1;
fde->type = de->d_type;
fde->namelen = strlen(de->d_name);
memcpy(fde->name, de->d_name, fde->namelen + 1);
fuse_reply(fuse, hdr->unique, fde,
FUSE_DIRENT_ALIGN(sizeof(struct fuse_dirent) + fde->namelen));
return NO_STATUS;
}
static int handle_releasedir(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_release_in* req)
{
struct dirhandle *h = id_to_ptr(req->fh);
TRACE("[%d] RELEASEDIR %p\n", handler->token, h);
closedir(h->d);
free(h);
return 0;
}
static int handle_init(struct fuse* fuse, struct fuse_handler* handler,
const struct fuse_in_header* hdr, const struct fuse_init_in* req)
{
struct fuse_init_out out;
TRACE("[%d] INIT ver=%d.%d maxread=%d flags=%x\n",
handler->token, req->major, req->minor, req->max_readahead, req->flags);
out.major = FUSE_KERNEL_VERSION;
out.minor = FUSE_KERNEL_MINOR_VERSION;
out.max_readahead = req->max_readahead;
out.flags = FUSE_ATOMIC_O_TRUNC | FUSE_BIG_WRITES;
out.max_background = 32;
out.congestion_threshold = 32;
out.max_write = MAX_WRITE;
fuse_reply(fuse, hdr->unique, &out, sizeof(out));
return NO_STATUS;
}
static int handle_fuse_request(struct fuse *fuse, struct fuse_handler* handler,
const struct fuse_in_header *hdr, const void *data, size_t data_len)
{
switch (hdr->opcode) {
case FUSE_LOOKUP: { /* bytez[] -> entry_out */
const char* name = data;
return handle_lookup(fuse, handler, hdr, name);
}
case FUSE_FORGET: {
const struct fuse_forget_in *req = data;
return handle_forget(fuse, handler, hdr, req);
}
case FUSE_GETATTR: { /* getattr_in -> attr_out */
const struct fuse_getattr_in *req = data;
return handle_getattr(fuse, handler, hdr, req);
}
case FUSE_SETATTR: { /* setattr_in -> attr_out */
const struct fuse_setattr_in *req = data;
return handle_setattr(fuse, handler, hdr, req);
}
// case FUSE_READLINK:
// case FUSE_SYMLINK:
case FUSE_MKNOD: { /* mknod_in, bytez[] -> entry_out */
const struct fuse_mknod_in *req = data;
const char *name = ((const char*) data) + sizeof(*req);
return handle_mknod(fuse, handler, hdr, req, name);
}
case FUSE_MKDIR: { /* mkdir_in, bytez[] -> entry_out */
const struct fuse_mkdir_in *req = data;
const char *name = ((const char*) data) + sizeof(*req);
return handle_mkdir(fuse, handler, hdr, req, name);
}
case FUSE_UNLINK: { /* bytez[] -> */
const char* name = data;
return handle_unlink(fuse, handler, hdr, name);
}
case FUSE_RMDIR: { /* bytez[] -> */
const char* name = data;
return handle_rmdir(fuse, handler, hdr, name);
}
case FUSE_RENAME: { /* rename_in, oldname, newname -> */
const struct fuse_rename_in *req = data;
const char *old_name = ((const char*) data) + sizeof(*req);
const char *new_name = old_name + strlen(old_name) + 1;
return handle_rename(fuse, handler, hdr, req, old_name, new_name);
}
// case FUSE_LINK:
case FUSE_OPEN: { /* open_in -> open_out */
const struct fuse_open_in *req = data;
return handle_open(fuse, handler, hdr, req);
}
case FUSE_READ: { /* read_in -> byte[] */
const struct fuse_read_in *req = data;
return handle_read(fuse, handler, hdr, req);
}
case FUSE_WRITE: { /* write_in, byte[write_in.size] -> write_out */
const struct fuse_write_in *req = data;
const void* buffer = (const __u8*)data + sizeof(*req);
return handle_write(fuse, handler, hdr, req, buffer);
}
case FUSE_STATFS: { /* getattr_in -> attr_out */
return handle_statfs(fuse, handler, hdr);
}
case FUSE_RELEASE: { /* release_in -> */
const struct fuse_release_in *req = data;
return handle_release(fuse, handler, hdr, req);
}
case FUSE_FSYNC: {
const struct fuse_fsync_in *req = data;
return handle_fsync(fuse, handler, hdr, req);
}
// case FUSE_SETXATTR:
// case FUSE_GETXATTR:
// case FUSE_LISTXATTR:
// case FUSE_REMOVEXATTR:
case FUSE_FLUSH: {
return handle_flush(fuse, handler, hdr);
}
case FUSE_OPENDIR: { /* open_in -> open_out */
const struct fuse_open_in *req = data;
return handle_opendir(fuse, handler, hdr, req);
}
case FUSE_READDIR: {
const struct fuse_read_in *req = data;
return handle_readdir(fuse, handler, hdr, req);
}
case FUSE_RELEASEDIR: { /* release_in -> */
const struct fuse_release_in *req = data;
return handle_releasedir(fuse, handler, hdr, req);
}
// case FUSE_FSYNCDIR:
case FUSE_INIT: { /* init_in -> init_out */
const struct fuse_init_in *req = data;
return handle_init(fuse, handler, hdr, req);
}
default: {
TRACE("[%d] NOTIMPL op=%d uniq=%llx nid=%llx\n",
handler->token, hdr->opcode, hdr->unique, hdr->nodeid);
return -ENOSYS;
}
}
}
static void handle_fuse_requests(struct fuse_handler* handler)
{
struct fuse* fuse = handler->fuse;
for (;;) {
ssize_t len = read(fuse->fd,
handler->request_buffer, sizeof(handler->request_buffer));
if (len < 0) {
if (errno != EINTR) {
ERROR("[%d] handle_fuse_requests: errno=%d\n", handler->token, errno);
}
continue;
}
if ((size_t)len < sizeof(struct fuse_in_header)) {
ERROR("[%d] request too short: len=%zu\n", handler->token, (size_t)len);
continue;
}
const struct fuse_in_header *hdr = (void*)handler->request_buffer;
if (hdr->len != (size_t)len) {
ERROR("[%d] malformed header: len=%zu, hdr->len=%u\n",
handler->token, (size_t)len, hdr->len);
continue;
}
const void *data = handler->request_buffer + sizeof(struct fuse_in_header);
size_t data_len = len - sizeof(struct fuse_in_header);
__u64 unique = hdr->unique;
int res = handle_fuse_request(fuse, handler, hdr, data, data_len);
/* We do not access the request again after this point because the underlying
* buffer storage may have been reused while processing the request. */
if (res != NO_STATUS) {
if (res) {
TRACE("[%d] ERROR %d\n", handler->token, res);
}
fuse_status(fuse, unique, res);
}
}
}
static void* start_handler(void* data)
{
struct fuse_handler* handler = data;
handle_fuse_requests(handler);
return NULL;
}
static int ignite_fuse(struct fuse* fuse, int num_threads)
{
struct fuse_handler* handlers;
int i;
handlers = malloc(num_threads * sizeof(struct fuse_handler));
if (!handlers) {
ERROR("cannot allocate storage for threads");
return -ENOMEM;
}
for (i = 0; i < num_threads; i++) {
handlers[i].fuse = fuse;
handlers[i].token = i;
}
for (i = 1; i < num_threads; i++) {
pthread_t thread;
int res = pthread_create(&thread, NULL, start_handler, &handlers[i]);
if (res) {
ERROR("failed to start thread #%d, error=%d", i, res);
goto quit;
}
}
handle_fuse_requests(&handlers[0]);
ERROR("terminated prematurely");
/* don't bother killing all of the other threads or freeing anything,
* should never get here anyhow */
quit:
exit(1);
}
static int usage()
{
ERROR("usage: sdcard [-t<threads>] <source_path> <dest_path> <uid> <gid>\n"
" -t<threads>: specify number of threads to use, default -t%d\n"
"\n", DEFAULT_NUM_THREADS);
return 1;
}
static int run(const char* source_path, const char* dest_path, uid_t uid, gid_t gid,
int num_threads) {
int fd;
char opts[256];
int res;
struct fuse fuse;
/* cleanup from previous instance, if necessary */
umount2(dest_path, 2);
fd = open("/dev/fuse", O_RDWR);
if (fd < 0){
ERROR("cannot open fuse device (error %d)\n", errno);
return -1;
}
snprintf(opts, sizeof(opts),
"fd=%i,rootmode=40000,default_permissions,allow_other,user_id=%d,group_id=%d",
fd, uid, gid);
res = mount("/dev/fuse", dest_path, "fuse", MS_NOSUID | MS_NODEV, opts);
if (res < 0) {
ERROR("cannot mount fuse filesystem (error %d)\n", errno);
goto error;
}
res = setgid(gid);
if (res < 0) {
ERROR("cannot setgid (error %d)\n", errno);
goto error;
}
res = setuid(uid);
if (res < 0) {
ERROR("cannot setuid (error %d)\n", errno);
goto error;
}
fuse_init(&fuse, fd, source_path);
umask(0);
res = ignite_fuse(&fuse, num_threads);
/* we do not attempt to umount the file system here because we are no longer
* running as the root user */
error:
close(fd);
return res;
}
int main(int argc, char **argv)
{
int res;
const char *source_path = NULL;
const char *dest_path = NULL;
uid_t uid = 0;
gid_t gid = 0;
int num_threads = DEFAULT_NUM_THREADS;
int i;
struct rlimit rlim;
for (i = 1; i < argc; i++) {
char* arg = argv[i];
if (!strncmp(arg, "-t", 2))
num_threads = strtoul(arg + 2, 0, 10);
else if (!source_path)
source_path = arg;
else if (!dest_path)
dest_path = arg;
else if (!uid) {
char* endptr = NULL;
errno = 0;
uid = strtoul(arg, &endptr, 10);
if (*endptr != '\0' || errno != 0) {
ERROR("Invalid uid");
return usage();
}
} else if (!gid) {
char* endptr = NULL;
errno = 0;
gid = strtoul(arg, &endptr, 10);
if (*endptr != '\0' || errno != 0) {
ERROR("Invalid gid");
return usage();
}
} else {
ERROR("too many arguments\n");
return usage();
}
}
if (!source_path) {
ERROR("no source path specified\n");
return usage();
}
if (!dest_path) {
ERROR("no dest path specified\n");
return usage();
}
if (!uid || !gid) {
ERROR("uid and gid must be nonzero\n");
return usage();
}
if (num_threads < 1) {
ERROR("number of threads must be at least 1\n");
return usage();
}
rlim.rlim_cur = 8192;
rlim.rlim_max = 8192;
if (setrlimit(RLIMIT_NOFILE, &rlim)) {
ERROR("Error setting RLIMIT_NOFILE, errno = %d\n", errno);
}
res = run(source_path, dest_path, uid, gid, num_threads);
return res < 0 ? 1 : 0;
}
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