int
vfs_open(char *path, uint32_t open_flags, struct inode **node_store) {
bool can_write = 0;
switch (open_flags & O_ACCMODE) {
case O_RDONLY:
break;
case O_WRONLY:
case O_RDWR:
can_write = 1;
break;
default:
return -E_INVAL;
}
if (open_flags & O_TRUNC) {
if (!can_write) {
return -E_INVAL;
}
}
int ret;
struct inode *dir, *node;
if (open_flags & O_CREAT) {
char *name;
bool excl = (open_flags & O_EXCL) != 0;
if ((ret = vfs_lookup_parent(path, &dir, &name)) != 0) {
return ret;
}
ret = vop_create(dir, name, excl, &node);
vop_ref_dec(dir);
}
else {
ret = vfs_lookup(path, &node);
}
if (ret != 0) {
return ret;
}
assert(node != NULL);
if ((ret = vop_open(node, open_flags)) != 0) {
vop_ref_dec(node);
return ret;
}
vop_open_inc(node);
if (open_flags & O_TRUNC) {
if ((ret = vop_truncate(node, 0)) != 0) {
vop_open_dec(node);
vop_ref_dec(node);
return ret;
}
}
*node_store = node;
return 0;
}
/*
* sfs_tryseek - Check if seeking to the specified position within the file is legal.
*/
static int
sfs_tryseek(struct inode *node, off_t pos) {
if (pos < 0 || pos >= SFS_MAX_FILE_SIZE) {
return -E_INVAL;
}
struct sfs_inode *sin = vop_info(node, sfs_inode);
if (pos > sin->din->size) {
return vop_truncate(node, pos);
}
return 0;
}
/*
* sfs_reclaim - Free all resources inode occupied . Called when inode is no longer in use.
*/
static int
sfs_reclaim(struct inode *node) {
struct sfs_fs *sfs = fsop_info(vop_fs(node), sfs);
struct sfs_inode *sin = vop_info(node, sfs_inode);
int ret = -E_BUSY;
uint32_t ent;
lock_sfs_fs(sfs);
assert(sin->reclaim_count > 0);
if ((-- sin->reclaim_count) != 0 || inode_ref_count(node) != 0) {
goto failed_unlock;
}
if (sin->din->nlinks == 0) {
if ((ret = vop_truncate(node, 0)) != 0) {
goto failed_unlock;
}
}
if (sin->dirty) {
if ((ret = vop_fsync(node)) != 0) {
goto failed_unlock;
}
}
sfs_remove_links(sin);
unlock_sfs_fs(sfs);
if (sin->din->nlinks == 0) {
sfs_block_free(sfs, sin->ino);
if ((ent = sin->din->indirect) != 0) {
sfs_block_free(sfs, ent);
}
}
kfree(sin->din);
vop_kill(node);
return 0;
failed_unlock:
unlock_sfs_fs(sfs);
return ret;
}
