int
nffs_dir_open(const char *path, struct nffs_dir **out_dir)
{
struct nffs_inode_entry *parent_inode_entry;
struct nffs_dir *dir;
int rc;
rc = nffs_path_find_inode_entry(path, &parent_inode_entry);
if (rc != 0) {
return rc;
}
if (!nffs_hash_id_is_dir(parent_inode_entry->nie_hash_entry.nhe_id)) {
return FS_EINVAL;
}
dir = nffs_dir_alloc();
if (dir == NULL) {
return FS_ENOMEM;
}
dir->nd_parent_inode_entry = parent_inode_entry;
dir->nd_parent_inode_entry->nie_refcnt++;
memset(&dir->nd_dirent, 0, sizeof dir->nd_dirent);
*out_dir = dir;
return 0;
}
/**
* Tells you whether the specified directory entry is a sub-directory or a
* regular file.
*
* @param dirent The directory entry to query.
*
* @return 1: The entry is a directory;
* 0: The entry is a regular file.
*/
static int
nffs_dirent_is_dir(const struct fs_dirent *fs_dirent)
{
uint32_t id;
const struct nffs_dirent *dirent = (const struct nffs_dirent *)fs_dirent;
nffs_lock();
assert(dirent != NULL && dirent->nde_inode_entry != NULL);
id = dirent->nde_inode_entry->nie_hash_entry.nhe_id;
nffs_unlock();
return nffs_hash_id_is_dir(id);
}
/**
* If the specified inode entry is a dummy directory, this function moves
* all its children to the lost+found directory.
*
* @param inode_entry The parent inode to test and empty.
*
* @return 0 on success; nonzero on failure.
*/
static int
nffs_restore_migrate_orphan_children(struct nffs_inode_entry *inode_entry)
{
struct nffs_inode_entry *lost_found_sub;
struct nffs_inode_entry *child_entry;
char buf[32];
int rc;
if (!nffs_hash_id_is_dir(inode_entry->nie_hash_entry.nhe_id)) {
/* Not a directory. */
return 0;
}
if (inode_entry->nie_refcnt != 0) {
/* Not a dummy. */
return 0;
}
if (SLIST_EMPTY(&inode_entry->nie_child_list)) {
/* No children to migrate. */
return 0;
}
/* Create a directory in lost+found to hold the dummy directory's
* contents.
*/
strcpy(buf, "/lost+found/");
u32toa(&buf[strlen(buf)], inode_entry->nie_hash_entry.nhe_id);
rc = nffs_path_new_dir(buf, &lost_found_sub);
if (rc != 0 && rc != FS_EEXIST) {
return rc;
}
/* Move each child into the new subdirectory. */
while ((child_entry = SLIST_FIRST(&inode_entry->nie_child_list)) != NULL) {
rc = nffs_inode_rename(child_entry, lost_found_sub, NULL);
if (rc != 0) {
return rc;
}
}
return 0;
}
/**
* Performs a file open operation.
*
* @param out_file On success, a pointer to the newly-created file
* handle gets written here.
* @param path The path of the file to open.
* @param access_flags Flags controlling file access; see nffs_open() for
* details.
*
* @return 0 on success; nonzero on failure.
*/
int
nffs_file_open(struct nffs_file **out_file, const char *path,
uint8_t access_flags)
{
struct nffs_path_parser parser;
struct nffs_inode_entry *parent;
struct nffs_inode_entry *inode;
struct nffs_file *file;
int rc;
file = NULL;
/* Reject invalid access flag combinations. */
if (!(access_flags & (FS_ACCESS_READ | FS_ACCESS_WRITE))) {
rc = FS_EINVAL;
goto err;
}
if (access_flags & (FS_ACCESS_APPEND | FS_ACCESS_TRUNCATE) &&
!(access_flags & FS_ACCESS_WRITE)) {
rc = FS_EINVAL;
goto err;
}
if (access_flags & FS_ACCESS_APPEND &&
access_flags & FS_ACCESS_TRUNCATE) {
rc = FS_EINVAL;
goto err;
}
file = nffs_file_alloc();
if (file == NULL) {
rc = FS_ENOMEM;
goto err;
}
nffs_path_parser_new(&parser, path);
rc = nffs_path_find(&parser, &inode, &parent);
if (rc == FS_ENOENT && parser.npp_token_type == NFFS_PATH_TOKEN_LEAF) {
/* The path is valid, but the file does not exist. This is an error
* for read-only opens.
*/
if (!(access_flags & FS_ACCESS_WRITE)) {
goto err;
}
/* Make sure the parent directory exists. */
if (parent == NULL) {
goto err;
}
/* Create a new file at the specified path. */
rc = nffs_file_new(parent, parser.npp_token, parser.npp_token_len, 0,
&file->nf_inode_entry);
if (rc != 0) {
goto err;
}
} else if (rc == 0) {
/* The file already exists. */
/* Reject an attempt to open a directory. */
if (nffs_hash_id_is_dir(inode->nie_hash_entry.nhe_id)) {
rc = FS_EINVAL;
goto err;
}
if (access_flags & FS_ACCESS_TRUNCATE) {
/* The user is truncating the file. Unlink the old file and create
* a new one in its place.
*/
nffs_path_unlink(path);
rc = nffs_file_new(parent, parser.npp_token, parser.npp_token_len,
0, &file->nf_inode_entry);
if (rc != 0) {
goto err;
}
} else {
/* The user is not truncating the file. Point the file handle to
* the existing inode.
*/
file->nf_inode_entry = inode;
}
} else {
/* Invalid path. */
goto err;
}
if (access_flags & FS_ACCESS_APPEND) {
rc = nffs_inode_data_len(file->nf_inode_entry, &file->nf_offset);
if (rc != 0) {
goto err;
}
} else {
file->nf_offset = 0;
}
file->nf_inode_entry->nie_refcnt++;
file->nf_access_flags = access_flags;
*out_file = file;
return 0;
err:
nffs_file_free(file);
return rc;
}
/**
* Determines if the specified inode should be added to the RAM representation
* and adds it if appropriate.
*
* @param disk_inode The inode just read from flash.
* @param area_idx The index of the area containing the inode.
* @param area_offset The offset within the area of the inode.
*
* @return 0 on success; nonzero on failure.
*/
static int
nffs_restore_inode(const struct nffs_disk_inode *disk_inode, uint8_t area_idx,
uint32_t area_offset)
{
struct nffs_inode_entry *inode_entry;
struct nffs_inode_entry *parent;
struct nffs_inode inode;
struct nffs_hash_entry *lastblock_entry = NULL;
int new_inode;
int do_add;
int rc;
new_inode = 0;
/* Check the inode's CRC. If the inode is corrupt, discard it. */
rc = nffs_crc_disk_inode_validate(disk_inode, area_idx, area_offset);
if (rc != 0) {
goto err;
}
inode_entry = nffs_hash_find_inode(disk_inode->ndi_id);
/*
* Inode has already been restored. Determine whether this version
* from disk should replace the previous version referenced in RAM.
*/
if (inode_entry != NULL) {
if (disk_inode->ndi_flags & NFFS_INODE_FLAG_DELETED) {
/*
* Restore this inode even though deleted on disk
* so the additional restored blocks have a place to go
*/
NFFS_LOG(DEBUG, "restoring deleted inode %x\n",
(unsigned int)disk_inode->ndi_id);
nffs_inode_setflags(inode_entry, NFFS_INODE_FLAG_DELETED);
}
/*
* inodes get replaced if they're dummy entries (i.e. allocated
* as place holders until the actual inode is restored), or this is
* a more recent version of the inode which supercedes the old.
*/
rc = nffs_restore_inode_gets_replaced(inode_entry, disk_inode, &do_add);
if (rc != 0) {
goto err;
}
if (do_add) { /* replace in this case */
if (!nffs_inode_is_dummy(inode_entry)) {
/*
* if it's not a dummy, read block from flash
*/
rc = nffs_inode_from_entry(&inode, inode_entry);
if (rc != 0) {
return rc;
}
/*
* inode is known to be obsolete
*/
if (nffs_inode_getflags(inode_entry,
NFFS_INODE_FLAG_OBSOLETE)) {
nffs_inode_unsetflags(inode_entry,
NFFS_INODE_FLAG_OBSOLETE);
}
if (inode.ni_parent != NULL) {
nffs_inode_remove_child(&inode);
}
/*
* If this is a delete record, subsequent inode and restore
* records from flash may be ignored.
* If the parent is NULL, this inode has been deleted. (old)
* XXX if we could count on delete records for every inode,
* we wouldn't need to check for the root directory looking
* like a delete record because of it's parent ID.
*/
if (inode_entry->nie_hash_entry.nhe_id != NFFS_ID_ROOT_DIR) {
if (disk_inode->ndi_flags & NFFS_INODE_FLAG_DELETED ||
disk_inode->ndi_parent_id == NFFS_ID_NONE) {
nffs_inode_setflags(inode_entry,
NFFS_INODE_FLAG_DELETED);
}
}
} else {
/*
* The existing inode entry was added as dummy.
* The restore operation clears that state.
*/
/* If it's a directory, it was added as a parent to
* one of it's children who were restored first.
*/
if (nffs_inode_getflags(inode_entry,
NFFS_INODE_FLAG_DUMMYPARENT)) {
assert(nffs_hash_id_is_dir(inode_entry->nie_hash_entry.nhe_id));
nffs_inode_unsetflags(inode_entry,
NFFS_INODE_FLAG_DUMMYPARENT);
}
/*
* If it's a file, it was added to store a lastblock
*/
if (nffs_inode_getflags(inode_entry,
NFFS_INODE_FLAG_DUMMYINOBLK)) {
assert(nffs_hash_id_is_file(inode_entry->nie_hash_entry.nhe_id));
nffs_inode_unsetflags(inode_entry,
NFFS_INODE_FLAG_DUMMYINOBLK);
}
/*
* Also, since it's a dummy, clear this flag too
*/
if (nffs_inode_getflags(inode_entry, NFFS_INODE_FLAG_DUMMY)) {
nffs_inode_unsetflags(inode_entry, NFFS_INODE_FLAG_DUMMY);
}
}
/*
* Update location to reference new location in flash
*/
inode_entry->nie_hash_entry.nhe_flash_loc =
nffs_flash_loc(area_idx, area_offset);
}
} else {
inode_entry = nffs_inode_entry_alloc();
if (inode_entry == NULL) {
rc = FS_ENOMEM;
goto err;
}
new_inode = 1;
do_add = 1;
inode_entry->nie_hash_entry.nhe_id = disk_inode->ndi_id;
inode_entry->nie_hash_entry.nhe_flash_loc =
nffs_flash_loc(area_idx, area_offset);
inode_entry->nie_last_block_entry = NULL; /* for now */
nffs_hash_insert(&inode_entry->nie_hash_entry);
}
/*
* inode object has been restored and the entry is in the hash
* Check whether the lastblock and parent have also been restored
* and link up or allocate dummy entries as appropriate.
*/
if (do_add) {
inode_entry->nie_refcnt = 1;
if (disk_inode->ndi_flags & NFFS_INODE_FLAG_DELETED) {
/*
* Restore this inode even though deleted on disk
* so the additional restored blocks have a place to go
*/
NFFS_LOG(DEBUG, "restoring deleted inode %x\n",
(unsigned int)disk_inode->ndi_id);
nffs_inode_setflags(inode_entry, NFFS_INODE_FLAG_DELETED);
}
/*
* Inode has a lastblock on disk.
* Add reference to last block entry if in hash table
* otherwise add a dummy block entry for later update
*/
if (disk_inode->ndi_lastblock_id != NFFS_ID_NONE &&
nffs_hash_id_is_file(inode_entry->nie_hash_entry.nhe_id)) {
lastblock_entry =
nffs_hash_find_block(disk_inode->ndi_lastblock_id);
/*
* Lastblock has already been restored.
*/
if (lastblock_entry != NULL) {
if (lastblock_entry->nhe_id == disk_inode->ndi_lastblock_id) {
inode_entry->nie_last_block_entry = lastblock_entry;
}
} else {
/*
* Insert a temporary reference to a 'dummy' block entry
* When block is restored, it will update this dummy and
* the entry of this inode is updated to flash location
*/
rc = nffs_block_entry_reserve(&lastblock_entry);
if (lastblock_entry == NULL) {
rc = FS_ENOMEM;
goto err;
}
lastblock_entry->nhe_id = disk_inode->ndi_lastblock_id;
lastblock_entry->nhe_flash_loc = NFFS_FLASH_LOC_NONE;
inode_entry->nie_last_block_entry = lastblock_entry;
nffs_inode_setflags(inode_entry, NFFS_INODE_FLAG_DUMMYLSTBLK);
nffs_hash_insert(lastblock_entry);
if (lastblock_entry->nhe_id >= nffs_hash_next_block_id) {
nffs_hash_next_block_id = lastblock_entry->nhe_id + 1;
}
}
}
if (disk_inode->ndi_parent_id != NFFS_ID_NONE) {
parent = nffs_hash_find_inode(disk_inode->ndi_parent_id);
/*
* The parent directory for this inode hasn't been restored yet.
* Add a dummy directory so it can be added as a child.
* When the parent inode is restored, it's hash entry will be
* updated with the flash location.
*/
if (parent == NULL) {
rc = nffs_restore_dummy_inode(disk_inode->ndi_parent_id,
&parent);
/*
* Set the dummy parent flag in the new parent.
* It's turned off above when restored.
*/
nffs_inode_setflags(parent, NFFS_INODE_FLAG_DUMMYPARENT);
if (rc != 0) {
goto err;
}
}
rc = nffs_inode_add_child(parent, inode_entry);
if (rc != 0) {
goto err;
}
}
if (inode_entry->nie_hash_entry.nhe_id == NFFS_ID_ROOT_DIR) {
nffs_root_dir = inode_entry;
nffs_inode_setflags(nffs_root_dir, NFFS_INODE_FLAG_INTREE);
}
}
if (nffs_hash_id_is_file(inode_entry->nie_hash_entry.nhe_id)) {
NFFS_LOG(DEBUG, "restoring file; id=0x%08x\n",
(unsigned int)inode_entry->nie_hash_entry.nhe_id);
if (inode_entry->nie_hash_entry.nhe_id >= nffs_hash_next_file_id) {
nffs_hash_next_file_id = inode_entry->nie_hash_entry.nhe_id + 1;
}
} else {
NFFS_LOG(DEBUG, "restoring dir; id=0x%08x\n",
(unsigned int)inode_entry->nie_hash_entry.nhe_id);
if (inode_entry->nie_hash_entry.nhe_id >= nffs_hash_next_dir_id) {
nffs_hash_next_dir_id = inode_entry->nie_hash_entry.nhe_id + 1;
}
}
return 0;
err:
if (new_inode) {
assert(nffs_inode_getflags(inode_entry, NFFS_INODE_FLAG_INHASH));
nffs_hash_remove(&inode_entry->nie_hash_entry);
nffs_inode_entry_free(inode_entry);
}
return rc;
}