/*===========================================================================*
* fs_read *
*===========================================================================*/
int fs_read(void)
{
/* Read from a file.
*/
cp_grant_id_t gid;
struct inode *node;
off_t pos;
size_t len;
char *ptr;
int r;
if (fs_m_in.REQ_SEEK_POS_HI != 0)
return EIO;
/* Try to get inode by to its inode number. */
if ((node = find_inode(fs_m_in.REQ_INODE_NR)) == NULL)
return EINVAL;
/* Check whether the node is a regular file. */
if (!S_ISREG(node->i_stat.mode))
return EINVAL;
/* Get the values from the request message. */
gid = fs_m_in.REQ_GRANT;
pos = fs_m_in.REQ_SEEK_POS_LO;
/* Call the read hook, if any. */
if (!is_inode_deleted(node) && vtreefs_hooks->read_hook != NULL) {
len = fs_m_in.REQ_NBYTES;
/* On success, the read hook provides us with a pointer to the
* resulting data. This avoids copying overhead.
*/
r = vtreefs_hooks->read_hook(node, pos, &ptr, &len,
get_inode_cbdata(node));
assert(len >= 0 && len <= fs_m_in.REQ_NBYTES);
/* Copy the resulting data to user space. */
if (r == OK && len > 0) {
r = sys_safecopyto(fs_m_in.m_source, fs_m_in.REQ_GRANT,
0, (vir_bytes) ptr, len, D);
}
} else {
/* Feign an empty file. */
r = OK;
len = 0;
}
if (r == OK) {
fs_m_out.RES_SEEK_POS_HI = 0;
fs_m_out.RES_SEEK_POS_LO = pos + len;
fs_m_out.RES_NBYTES = len;
}
return r;
}
/*
* Resolve a path string to an inode.
*/
int
fs_lookup(ino_t dir_nr, char * name, struct fsdriver_node * node_details,
int * is_mountpt)
{
struct inode *node, *child;
int r;
if ((node = find_inode(dir_nr)) == NULL)
return EINVAL;
if (!S_ISDIR(node->i_stat.mode))
return ENOTDIR;
if (strlen(name) > PNAME_MAX)
return ENAMETOOLONG;
if (!strcmp(name, ".")) {
/* Stay in the given directory. */
child = node;
} else if (!strcmp(name, "..")) {
/* Progress into the parent directory. */
if ((child = get_parent_inode(node)) == NULL)
return ENOENT; /* deleted? should not be possible */
} else {
/* Progress into a directory entry. Call the lookup hook, if
* present, before doing the actual lookup.
*/
if (!is_inode_deleted(node) &&
vtreefs_hooks->lookup_hook != NULL) {
r = vtreefs_hooks->lookup_hook(node, name,
get_inode_cbdata(node));
if (r != OK) return r;
}
if ((child = get_inode_by_name(node, name)) == NULL)
return ENOENT;
}
/* On success, open the resulting file and return its details. */
ref_inode(child);
node_details->fn_ino_nr = get_inode_number(child);
node_details->fn_mode = child->i_stat.mode;
node_details->fn_size = child->i_stat.size;
node_details->fn_uid = child->i_stat.uid;
node_details->fn_gid = child->i_stat.gid;
node_details->fn_dev = child->i_stat.dev;
*is_mountpt = FALSE;
return OK;
}
/*===========================================================================*
* fs_stat *
*===========================================================================*/
PUBLIC int fs_stat(void)
{
/* Retrieve file status.
*/
char path[PATH_MAX];
struct stat statbuf;
time_t cur_time;
struct inode *node;
int r;
if ((node = find_inode(fs_m_in.REQ_INODE_NR)) == NULL)
return EINVAL;
memset(&statbuf, 0, sizeof(struct stat));
/* Fill in the basic info. */
statbuf.st_dev = fs_dev;
statbuf.st_ino = get_inode_number(node);
statbuf.st_mode = node->i_stat.mode;
statbuf.st_nlink = !is_inode_deleted(node);
statbuf.st_uid = node->i_stat.uid;
statbuf.st_gid = node->i_stat.gid;
statbuf.st_rdev = (dev_t) node->i_stat.dev;
statbuf.st_size = node->i_stat.size;
/* If it is a symbolic link, return the size of the link target. */
if (S_ISLNK(node->i_stat.mode) && vtreefs_hooks->rdlink_hook != NULL) {
r = vtreefs_hooks->rdlink_hook(node, path, sizeof(path),
get_inode_cbdata(node));
if (r == OK)
statbuf.st_size = strlen(path);
}
/* Take the current time as file time for all files. */
cur_time = time(NULL);
statbuf.st_atime = cur_time;
statbuf.st_mtime = cur_time;
statbuf.st_ctime = cur_time;
/* Copy the struct to user space. */
return sys_safecopyto(fs_m_in.m_source, fs_m_in.REQ_GRANT, 0,
(vir_bytes) &statbuf, (phys_bytes) sizeof(statbuf), D);
}
/*===========================================================================*
* fs_read *
*===========================================================================*/
ssize_t fs_read(ino_t ino_nr, struct fsdriver_data *data, size_t bytes,
off_t pos, int __unused call)
{
/* Read from a file.
*/
struct inode *node;
size_t len;
char *ptr;
int r;
/* Try to get inode by its inode number. */
if ((node = find_inode(ino_nr)) == NULL)
return EINVAL;
/* Check whether the node is a regular file. */
if (!S_ISREG(node->i_stat.mode))
return EINVAL;
/* Call the read hook, if any. */
if (!is_inode_deleted(node) && vtreefs_hooks->read_hook != NULL) {
len = bytes;
/* On success, the read hook provides us with a pointer to the
* resulting data. This avoids copying overhead.
*/
r = vtreefs_hooks->read_hook(node, pos, &ptr, &len,
get_inode_cbdata(node));
assert(len <= bytes);
/* Copy the resulting data to user space. */
if (r == OK && len > 0)
r = fsdriver_copyout(data, 0, ptr, len);
} else {
/* Feign an empty file. */
r = OK;
len = 0;
}
return (r != OK) ? r : len;
}
/*===========================================================================*
* fs_stat *
*===========================================================================*/
int fs_stat(ino_t ino_nr, struct stat *buf)
{
/* Retrieve file status.
*/
char path[PATH_MAX];
time_t cur_time;
struct inode *node;
int r;
if ((node = find_inode(ino_nr)) == NULL)
return EINVAL;
/* Fill in the basic info. */
buf->st_dev = fs_dev;
buf->st_ino = get_inode_number(node);
buf->st_mode = node->i_stat.mode;
buf->st_nlink = !is_inode_deleted(node);
buf->st_uid = node->i_stat.uid;
buf->st_gid = node->i_stat.gid;
buf->st_rdev = (dev_t) node->i_stat.dev;
buf->st_size = node->i_stat.size;
/* If it is a symbolic link, return the size of the link target. */
if (S_ISLNK(node->i_stat.mode) && vtreefs_hooks->rdlink_hook != NULL) {
r = vtreefs_hooks->rdlink_hook(node, path, sizeof(path),
get_inode_cbdata(node));
if (r == OK)
buf->st_size = strlen(path);
}
/* Take the current time as file time for all files. */
cur_time = clock_time(NULL);
buf->st_atime = cur_time;
buf->st_mtime = cur_time;
buf->st_ctime = cur_time;
return OK;
}
/*===========================================================================*
* fs_getdents *
*===========================================================================*/
ssize_t fs_getdents(ino_t ino_nr, struct fsdriver_data *data, size_t bytes,
off_t *posp)
{
/* Retrieve directory entries.
*/
struct fsdriver_dentry fsdentry;
struct inode *node, *child;
const char *name;
off_t pos;
int r, skip, get_next, indexed;
static char buf[GETDENTS_BUFSIZ];
if (*posp >= ULONG_MAX)
return EIO;
if ((node = find_inode(ino_nr)) == NULL)
return EINVAL;
indexed = node->i_indexed;
get_next = FALSE;
child = NULL;
/* Call the getdents hook, if any, to "refresh" the directory. */
if (!is_inode_deleted(node) && vtreefs_hooks->getdents_hook != NULL) {
r = vtreefs_hooks->getdents_hook(node, get_inode_cbdata(node));
if (r != OK) return r;
}
fsdriver_dentry_init(&fsdentry, data, bytes, buf, sizeof(buf));
do {
/* Determine which inode and name to use for this entry. */
pos = (*posp)++;
if (pos == 0) {
/* The "." entry. */
child = node;
name = ".";
}
else if (pos == 1) {
/* The ".." entry. */
child = get_parent_inode(node);
if (child == NULL)
child = node;
name = "..";
}
else if (pos - 2 < indexed) {
/* All indexed entries. */
child = get_inode_by_index(node, pos - 2);
/* If there is no inode with this particular index,
* continue with the next index number.
*/
if (child == NULL) continue;
name = child->i_name;
}
else {
/* All non-indexed entries. */
/* If this is the first loop iteration, first get to
* the non-indexed child identified by the current
* position.
*/
if (get_next == FALSE) {
skip = pos - indexed - 2;
child = get_first_inode(node);
/* Skip indexed children. */
while (child != NULL &&
child->i_index != NO_INDEX)
child = get_next_inode(child);
/* Skip to the right position. */
while (child != NULL && skip-- > 0)
child = get_next_inode(child);
get_next = TRUE;
}
else {
child = get_next_inode(child);
}
/* No more children? Then stop. */
if (child == NULL)
break;
assert(!is_inode_deleted(child));
name = child->i_name;
}
/* Add the directory entry to the output. */
r = fsdriver_dentry_add(&fsdentry,
(ino_t) get_inode_number(child), name, strlen(name),
IFTODT(child->i_stat.mode));
if (r < 0)
return r;
} while (r > 0);
return fsdriver_dentry_finish(&fsdentry);
}
/*===========================================================================*
* fs_getdents *
*===========================================================================*/
int fs_getdents(void)
{
/* Retrieve directory entries.
*/
struct inode *node, *child = NULL;
struct dirent *dent;
char *name;
size_t len, off, user_off, user_left;
off_t pos;
int r, skip, get_next, indexed;
static char buf[GETDENTS_BUFSIZ];
if (fs_m_in.REQ_SEEK_POS_HI != 0)
return EIO;
if ((node = find_inode(fs_m_in.REQ_INODE_NR)) == NULL)
return EINVAL;
off = 0;
user_off = 0;
user_left = fs_m_in.REQ_MEM_SIZE;
indexed = node->i_indexed;
get_next = FALSE;
child = NULL;
/* Call the getdents hook, if any, to "refresh" the directory. */
if (!is_inode_deleted(node) && vtreefs_hooks->getdents_hook != NULL) {
r = vtreefs_hooks->getdents_hook(node, get_inode_cbdata(node));
if (r != OK) return r;
}
for (pos = fs_m_in.REQ_SEEK_POS_LO; ; pos++) {
/* Determine which inode and name to use for this entry. */
if (pos == 0) {
/* The "." entry. */
child = node;
name = ".";
}
else if (pos == 1) {
/* The ".." entry. */
child = get_parent_inode(node);
if (child == NULL)
child = node;
name = "..";
}
else if (pos - 2 < indexed) {
/* All indexed entries. */
child = get_inode_by_index(node, pos - 2);
/* If there is no inode with this particular index,
* continue with the next index number.
*/
if (child == NULL) continue;
name = child->i_name;
}
else {
/* All non-indexed entries. */
/* If this is the first loop iteration, first get to
* the non-indexed child identified by the current
* position.
*/
if (get_next == FALSE) {
skip = pos - indexed - 2;
child = get_first_inode(node);
/* Skip indexed children. */
while (child != NULL &&
child->i_index != NO_INDEX)
child = get_next_inode(child);
/* Skip to the right position. */
while (child != NULL && skip-- > 0)
child = get_next_inode(child);
get_next = TRUE;
}
else {
child = get_next_inode(child);
}
/* No more children? Then stop. */
if (child == NULL)
break;
assert(!is_inode_deleted(child));
name = child->i_name;
}
len = DWORD_ALIGN(sizeof(struct dirent) + strlen(name));
/* Is the user buffer too small to store another record? */
if (user_off + off + len > user_left) {
/* Is the user buffer too small for even a single
* record?
*/
if (user_off == 0 && off == 0)
return EINVAL;
break;
}
/* If our own buffer cannot contain the new record, copy out
* first.
*/
if (off + len > sizeof(buf)) {
r = sys_safecopyto(fs_m_in.m_source, fs_m_in.REQ_GRANT,
user_off, (vir_bytes) buf, off, D);
if (r != OK) return r;
user_off += off;
user_left -= off;
off = 0;
}
/* Fill in the actual directory entry. */
dent = (struct dirent *) &buf[off];
dent->d_ino = get_inode_number(child);
dent->d_off = pos;
dent->d_reclen = len;
strcpy(dent->d_name, name);
off += len;
}
/* If there is anything left in our own buffer, copy that out now. */
if (off > 0) {
r = sys_safecopyto(fs_m_in.m_source, fs_m_in.REQ_GRANT,
user_off, (vir_bytes) buf, off, D);
if (r != OK)
return r;
user_off += off;
}
fs_m_out.RES_SEEK_POS_HI = 0;
fs_m_out.RES_SEEK_POS_LO = pos;
fs_m_out.RES_NBYTES = user_off;
return OK;
}