/*===========================================================================*
* go_down *
*===========================================================================*/
static int go_down(
char path[PATH_MAX], /* path to add the name to */
struct inode *parent, /* inode of the current directory */
char *name, /* name of the directory entry */
struct inode **res_ino, /* place to store resulting inode */
struct sffs_attr *attr /* place to store inode attributes */
)
{
/* Given a directory inode and a name, progress into a directory entry.
*/
struct inode *ino;
int r, stale = 0;
if ((r = push_path(path, name)) != OK)
return r;
dprintf(("%s: go_down: name '%s', path now '%s'\n", sffs_name, name, path));
ino = lookup_dentry(parent, name);
dprintf(("%s: lookup_dentry('%s') returned %p\n", sffs_name, name, ino));
if (ino != NULL)
r = verify_path(path, ino, attr, &stale);
else
r = sffs_table->t_getattr(path, attr);
dprintf(("%s: path query returned %d\n", sffs_name, r));
if (r != OK) {
if (ino != NULL) {
put_inode(ino);
ino = NULL;
}
if (!stale)
return r;
}
dprintf(("%s: name '%s'\n", sffs_name, name));
if (ino == NULL) {
if ((ino = get_free_inode()) == NULL)
return ENFILE;
dprintf(("%s: inode %p ref %d\n", sffs_name, ino, ino->i_ref));
ino->i_flags = MODE_TO_DIRFLAG(attr->a_mode);
add_dentry(parent, name, ino);
}
*res_ino = ino;
return OK;
}
/*===========================================================================*
* verify_path *
*===========================================================================*/
int verify_path(char path[PATH_MAX], struct inode *ino,
struct sffs_attr *attr, int *stale)
{
/* Given a path, and the inode associated with that path, verify if the inode
* still matches the real world. Obtain the attributes of the file identified
* by the given path, and see if they match. If not, possibly mark the inode
* as deleted and return an error. Only upon success is the inode guaranteed
* to be usable.
*
* The caller must set the a_mask field of the passed attr struct.
* If 'stale' is not NULL, the value it points to must be initialized to 0,
* and will be set to 1 if the path was valid but the inode wasn't.
*/
int r;
attr->a_mask |= SFFS_ATTR_MODE;
r = sffs_table->t_getattr(path, attr);
dprintf(("%s: verify_path: getattr('%s') returned %d\n",
sffs_name, path, r));
if (r != OK) {
/* If we are told that the path does not exist, delete the inode */
if (r == ENOENT || r == ENOTDIR)
del_dentry(ino);
return r; /* path isn't valid */
}
/* If the file type (reg, dir) isn't what we thought, delete the inode */
if ((ino->i_flags & I_DIR) != MODE_TO_DIRFLAG(attr->a_mode)) {
del_dentry(ino);
if (stale != NULL) *stale = 1;
return ENOENT; /* path is valid, inode wasn't */
}
return OK; /* path and inode are valid */
}
/*===========================================================================*
* do_getdents *
*===========================================================================*/
int do_getdents()
{
/* Retrieve directory entries.
*/
char name[NAME_MAX+1];
struct inode *ino, *child;
struct dirent *dent;
struct sffs_attr attr;
size_t len, off, user_off, user_left;
off_t pos;
int r;
/* must be at least sizeof(struct dirent) + NAME_MAX */
static char buf[BLOCK_SIZE];
attr.a_mask = SFFS_ATTR_MODE;
if ((ino = find_inode(m_in.REQ_INODE_NR)) == NULL)
return EINVAL;
if (m_in.REQ_SEEK_POS_HI != 0) return EINVAL;
if (!IS_DIR(ino)) return ENOTDIR;
/* We are going to need at least one free inode to store children in. */
if (!have_free_inode()) return ENFILE;
/* If we don't have a directory handle yet, get one now. */
if ((r = get_handle(ino)) != OK)
return r;
off = 0;
user_off = 0;
user_left = m_in.REQ_MEM_SIZE;
/* We use the seek position as file index number. The first position is for
* the "." entry, the second position is for the ".." entry, and the next
* position numbers each represent a file in the directory.
*/
for (pos = m_in.REQ_SEEK_POS_LO; ; pos++) {
/* Determine which inode and name to use for this entry.
* We have no idea whether the host will give us "." and/or "..",
* so generate our own and skip those from the host.
*/
if (pos == 0) {
/* Entry for ".". */
child = ino;
strcpy(name, ".");
get_inode(child);
}
else if (pos == 1) {
/* Entry for "..", but only when there is a parent. */
if (ino->i_parent == NULL)
continue;
child = ino->i_parent;
strcpy(name, "..");
get_inode(child);
}
else {
/* Any other entry, not being "." or "..". */
r = sffs_table->t_readdir(ino->i_dir, pos - 2, name,
sizeof(name), &attr);
if (r != OK) {
/* No more entries? Then close the handle and stop. */
if (r == ENOENT) {
put_handle(ino);
break;
}
/* FIXME: what if the error is ENAMETOOLONG? */
return r;
}
if (!strcmp(name, ".") || !strcmp(name, ".."))
continue;
if ((child = lookup_dentry(ino, name)) == NULL) {
child = get_free_inode();
/* We were promised a free inode! */
assert(child != NULL);
child->i_flags = MODE_TO_DIRFLAG(attr.a_mode);
add_dentry(ino, name, child);
}
}
len = DWORD_ALIGN(sizeof(struct dirent) + strlen(name));
/* Is the user buffer too small to store another record?
* Note that we will be rerequesting the same dentry upon a subsequent
* getdents call this way, but we really need the name length for this.
*/
if (user_off + off + len > user_left) {
put_inode(child);
/* 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(m_in.m_source, m_in.REQ_GRANT,
user_off, (vir_bytes) buf, off, D);
if (r != OK) {
put_inode(child);
return r;
}
user_off += off;
user_left -= off;
off = 0;
}
/* Fill in the actual directory entry. */
dent = (struct dirent *) &buf[off];
dent->d_ino = INODE_NR(child);
dent->d_off = pos;
dent->d_reclen = len;
strcpy(dent->d_name, name);
off += len;
put_inode(child);
}
/* If there is anything left in our own buffer, copy that out now. */
if (off > 0) {
r = sys_safecopyto(m_in.m_source, m_in.REQ_GRANT, user_off,
(vir_bytes) buf, off, D);
if (r != OK)
return r;
user_off += off;
}
m_out.RES_SEEK_POS_HI = 0;
m_out.RES_SEEK_POS_LO = pos;
m_out.RES_NBYTES = user_off;
return OK;
}
/*===========================================================================*
* do_getdents *
*===========================================================================*/
ssize_t do_getdents(ino_t ino_nr, struct fsdriver_data *data, size_t bytes,
off_t *posp)
{
/* Retrieve directory entries.
*/
struct fsdriver_dentry fsdentry;
char name[NAME_MAX+1];
struct inode *ino, *child;
struct sffs_attr attr;
off_t pos;
int r;
/* must be at least sizeof(struct dirent) + NAME_MAX */
static char buf[BLOCK_SIZE];
if ((ino = find_inode(ino_nr)) == NULL)
return EINVAL;
if (!IS_DIR(ino)) return ENOTDIR;
if (*posp < 0 || *posp >= ULONG_MAX) return EINVAL;
/* We are going to need at least one free inode to store children in. */
if (!have_free_inode()) return ENFILE;
/* If we don't have a directory handle yet, get one now. */
if ((r = get_handle(ino)) != OK)
return r;
fsdriver_dentry_init(&fsdentry, data, bytes, buf, sizeof(buf));
/* We use the seek position as file index number. The first position is for
* the "." entry, the second position is for the ".." entry, and the next
* position numbers each represent a file in the directory.
*/
do {
/* Determine which inode and name to use for this entry.
* We have no idea whether the host will give us "." and/or "..",
* so generate our own and skip those from the host.
*/
pos = (*posp)++;
if (pos == 0) {
/* Entry for ".". */
child = ino;
strcpy(name, ".");
get_inode(child);
}
else if (pos == 1) {
/* Entry for "..", but only when there is a parent. */
if (ino->i_parent == NULL)
continue;
child = ino->i_parent;
strcpy(name, "..");
get_inode(child);
}
else {
/* Any other entry, not being "." or "..". */
attr.a_mask = SFFS_ATTR_MODE;
r = sffs_table->t_readdir(ino->i_dir, pos - 2, name,
sizeof(name), &attr);
if (r != OK) {
/* No more entries? Then close the handle and stop. */
if (r == ENOENT) {
put_handle(ino);
break;
}
/* FIXME: what if the error is ENAMETOOLONG? */
return r;
}
if (!strcmp(name, ".") || !strcmp(name, ".."))
continue;
if ((child = lookup_dentry(ino, name)) == NULL) {
child = get_free_inode();
/* We were promised a free inode! */
assert(child != NULL);
child->i_flags = MODE_TO_DIRFLAG(attr.a_mode);
add_dentry(ino, name, child);
}
}
r = fsdriver_dentry_add(&fsdentry, INODE_NR(child), name, strlen(name),
IS_DIR(child) ? DT_DIR : DT_REG);
put_inode(child);
if (r < 0)
return r;
} while (r > 0);
return fsdriver_dentry_finish(&fsdentry);
}
