/*
* hfs_btree_free()
*
* Description:
* This function frees a (struct hfs_btree) obtained from hfs_btree_init().
* Called by hfs_put_super().
* Input Variable(s):
* struct hfs_btree *bt: pointer to the (struct hfs_btree) to free
* Output Variable(s):
* NONE
* Returns:
* void
* Preconditions:
* 'bt' is NULL or points to a "valid" (struct hfs_btree)
* Postconditions:
* If 'bt' points to a "valid" (struct hfs_btree) then all (struct
* hfs_bnode)s associated with 'bt' are freed by calling
* hfs_bnode_ditch() and the memory associated with the (struct
* hfs_btree) is freed.
* If 'bt' is NULL or not "valid" an error is printed and nothing
* is changed.
*/
void hfs_btree_free(struct hfs_btree *bt)
{
int lcv;
if (bt && (bt->magic == HFS_BTREE_MAGIC)) {
hfs_extent_free(&bt->entry.u.file.data_fork);
for (lcv=0; lcv<HFS_CACHELEN; ++lcv) {
#if defined(DEBUG_BNODES) || defined(DEBUG_ALL)
hfs_warn("deleting nodes from bucket %d:\n", lcv);
#endif
hfs_bnode_ditch(bt->cache[lcv]);
}
#if defined(DEBUG_BNODES) || defined(DEBUG_ALL)
hfs_warn("deleting header and bitmap nodes\n");
#endif
hfs_bnode_ditch(&bt->head);
#if defined(DEBUG_BNODES) || defined(DEBUG_ALL)
hfs_warn("deleting root node\n");
#endif
hfs_bnode_ditch(bt->root);
HFS_DELETE(bt);
} else if (bt) {
hfs_warn("hfs_btree_free: corrupted hfs_btree.\n");
}
}
/*
* relse_ext()
*
* Reduce the reference count of an in-core extent record by one,
* removing it from memory if the count falls to zero.
*/
static void relse_ext(struct hfs_extent *ext)
{
if (--ext->count || !ext->start) {
return;
}
ext->prev->next = ext->next;
if (ext->next) {
ext->next->prev = ext->prev;
}
HFS_DELETE(ext);
}
/*
* hfs_put_inode()
*
* This is the put_inode() entry in the super_operations for HFS
* filesystems. The purpose is to perform any filesystem-dependent
* cleanup necessary when the use-count of an inode falls to zero.
*/
void hfs_put_inode(struct inode * inode)
{
struct hfs_cat_entry *entry = HFS_I(inode)->entry;
hfs_cat_put(entry);
if (inode->i_count == 1) {
struct hfs_hdr_layout *tmp = HFS_I(inode)->layout;
if (tmp) {
HFS_I(inode)->layout = NULL;
HFS_DELETE(tmp);
}
}
}
/*
* hfs_put_inode()
*
* This is the put_inode() entry in the super_operations for HFS
* filesystems. The purpose is to perform any filesystem-dependent
* cleanup necessary when the use-count of an inode falls to zero.
*/
void hfs_put_inode(struct inode * inode)
{
struct hfs_cat_entry *entry = HFS_I(inode)->entry;
lock_kernel();
hfs_cat_put(entry);
if (atomic_read(&inode->i_count) == 1) {
struct hfs_hdr_layout *tmp = HFS_I(inode)->layout;
if (tmp) {
HFS_I(inode)->layout = NULL;
HFS_DELETE(tmp);
}
}
unlock_kernel();
}
/*
* new_extent()
*
* Description:
* Adds a new extent record to a fork, extending its physical length.
* Input Variable(s):
* struct hfs_fork *fork: the fork to extend
* struct hfs_extent *ext: the current last extent for 'fork'
* hfs_u16 ablock: the number of allocation blocks in 'fork'.
* hfs_u16 start: first allocation block to add to 'fork'.
* hfs_u16 len: the number of allocation blocks to add to 'fork'.
* hfs_u32 ablksz: number of sectors in an allocation block.
* Output Variable(s):
* NONE
* Returns:
* (struct hfs_extent *) the new extent or NULL
* Preconditions:
* 'fork' points to a valid (struct hfs_fork)
* 'ext' point to a valid (struct hfs_extent) which is the last in 'fork'
* 'ablock', 'start', 'len' and 'ablksz' are what they claim to be.
* Postconditions:
* If NULL is returned then no changes have been made to 'fork'.
* If the return value is non-NULL that it is the extent that has been
* added to 'fork' both in memory and on disk. The 'psize' field of
* 'fork' has been updated to reflect the new physical size.
*/
static struct hfs_extent *new_extent(struct hfs_fork *fork,
struct hfs_extent *ext,
hfs_u16 ablock, hfs_u16 start,
hfs_u16 len, hfs_u16 ablksz)
{
struct hfs_raw_extent raw;
struct hfs_ext_key key;
int error;
if (fork->entry->cnid == htonl(HFS_EXT_CNID)) {
/* Limit extents tree to the record in the MDB */
return NULL;
}
if (!HFS_NEW(ext->next)) {
return NULL;
}
ext->next->prev = ext;
ext->next->next = NULL;
ext = ext->next;
relse_ext(ext->prev);
ext->start = ablock;
ext->block[0] = start;
ext->length[0] = len;
ext->block[1] = 0;
ext->length[1] = 0;
ext->block[2] = 0;
ext->length[2] = 0;
ext->end = ablock + len - 1;
ext->count = 1;
write_extent(&raw, ext);
build_key(&key, fork, ablock);
error = hfs_binsert(fork->entry->mdb->ext_tree,
HFS_BKEY(&key), &raw, sizeof(raw));
if (error) {
ext->prev->next = NULL;
HFS_DELETE(ext);
return NULL;
}
set_cache(fork, ext);
return ext;
}
/*
* hfs_bnode_ditch()
*
* Description:
* This function deletes an entire linked list of bnodes, so it
* does not need to keep the linked list consistent as
* hfs_bnode_delete() does.
* Called by hfs_btree_init() for error cleanup and by hfs_btree_free().
* Input Variable(s):
* struct hfs_bnode *bn: pointer to the first (struct hfs_bnode) in
* the linked list to be deleted.
* Output Variable(s):
* NONE
* Returns:
* void
* Preconditions:
* 'bn' is NULL or points to a "valid" (struct hfs_bnode) with a 'prev'
* field of NULL.
* Postconditions:
* 'bn' and all (struct hfs_bnode)s in the chain of 'next' pointers
* are deleted, freeing the associated memory and hfs_buffer_put()ing
* the associated buffer.
*/
static void hfs_bnode_ditch(struct hfs_bnode *bn) {
struct hfs_bnode *tmp;
#if defined(DEBUG_BNODES) || defined(DEBUG_ALL)
extern int bnode_count;
#endif
while (bn != NULL) {
tmp = bn->next;
#if defined(DEBUG_BNODES) || defined(DEBUG_ALL)
hfs_warn("deleting node %d from tree %d with count %d\n",
bn->node, (int)ntohl(bn->tree->entry.cnid), bn->count);
--bnode_count;
#endif
hfs_buffer_put(bn->buf); /* safe: checks for NULL argument */
/* free all but the header */
if (bn->node) {
HFS_DELETE(bn);
}
bn = tmp;
}
}
/*
* delete_extent()
*
* Description:
* Deletes an extent record from a fork, reducing its physical length.
* Input Variable(s):
* struct hfs_fork *fork: the fork
* struct hfs_extent *ext: the current last extent for 'fork'
* Output Variable(s):
* NONE
* Returns:
* void
* Preconditions:
* 'fork' points to a valid (struct hfs_fork)
* 'ext' point to a valid (struct hfs_extent) which is the last in 'fork'
* and which is not also the first extent in 'fork'.
* Postconditions:
* The extent record has been removed if possible, and a warning has been
* printed otherwise.
*/
static void delete_extent(struct hfs_fork *fork, struct hfs_extent *ext)
{
struct hfs_mdb *mdb = fork->entry->mdb;
struct hfs_ext_key key;
int error;
if (fork->cache == ext) {
set_cache(fork, ext->prev);
}
ext->prev->next = NULL;
if (ext->count != 1) {
hfs_warn("hfs_truncate: extent has count %d.\n", ext->count);
}
lock_bitmap(mdb);
error = hfs_clear_vbm_bits(mdb, ext->block[2], ext->length[2]);
if (error) {
hfs_warn("hfs_truncate: error %d freeing blocks.\n", error);
}
error = hfs_clear_vbm_bits(mdb, ext->block[1], ext->length[1]);
if (error) {
hfs_warn("hfs_truncate: error %d freeing blocks.\n", error);
}
error = hfs_clear_vbm_bits(mdb, ext->block[0], ext->length[0]);
if (error) {
hfs_warn("hfs_truncate: error %d freeing blocks.\n", error);
}
unlock_bitmap(mdb);
build_key(&key, fork, ext->start);
error = hfs_bdelete(mdb->ext_tree, HFS_BKEY(&key));
if (error) {
hfs_warn("hfs_truncate: error %d deleting an extent.\n", error);
}
HFS_DELETE(ext);
}
/*
* hfs_btree_init()
*
* Description:
* Given some vital information from the MDB (HFS superblock),
* initializes the fields of a (struct hfs_btree).
* Input Variable(s):
* struct hfs_mdb *mdb: pointer to the MDB
* ino_t cnid: the CNID (HFS_CAT_CNID or HFS_EXT_CNID) of the B-tree
* hfs_u32 tsize: the size, in bytes, of the B-tree
* hfs_u32 csize: the size, in bytes, of the clump size for the B-tree
* Output Variable(s):
* NONE
* Returns:
* (struct hfs_btree *): pointer to the initialized hfs_btree on success,
* or NULL on failure
* Preconditions:
* 'mdb' points to a "valid" (struct hfs_mdb)
* Postconditions:
* Assuming the inputs are what they claim to be, no errors occur
* reading from disk, and no inconsistencies are noticed in the data
* read from disk, the return value is a pointer to a "valid"
* (struct hfs_btree). If there are errors reading from disk or
* inconsistencies are noticed in the data read from disk, then and
* all resources that were allocated are released and NULL is
* returned. If the inputs are not what they claim to be or if they
* are unnoticed inconsistencies in the data read from disk then the
* returned hfs_btree is probably going to lead to errors when it is
* used in a non-trivial way.
*/
struct hfs_btree * hfs_btree_init(struct hfs_mdb *mdb, ino_t cnid,
hfs_byte_t ext[12],
hfs_u32 tsize, hfs_u32 csize)
{
struct hfs_btree * bt;
struct BTHdrRec * th;
struct hfs_bnode * tmp;
unsigned int next;
#if defined(DEBUG_HEADER) || defined(DEBUG_ALL)
unsigned char *p, *q;
#endif
if (!mdb || !ext || !HFS_NEW(bt)) {
goto bail3;
}
bt->magic = HFS_BTREE_MAGIC;
bt->sys_mdb = mdb->sys_mdb;
bt->reserved = 0;
bt->lock = 0;
hfs_init_waitqueue(&bt->wait);
bt->dirt = 0;
memset(bt->cache, 0, sizeof(bt->cache));
#if 0 /* this is a fake entry. so we don't need to initialize it. */
memset(&bt->entry, 0, sizeof(bt->entry));
hfs_init_waitqueue(&bt->entry.wait);
INIT_LIST_HEAD(&bt->entry.hash);
INIT_LIST_HEAD(&bt->entry.list);
#endif
bt->entry.mdb = mdb;
bt->entry.cnid = cnid;
bt->entry.type = HFS_CDR_FIL;
bt->entry.u.file.magic = HFS_FILE_MAGIC;
bt->entry.u.file.clumpablks = (csize / mdb->alloc_blksz)
>> HFS_SECTOR_SIZE_BITS;
bt->entry.u.file.data_fork.entry = &bt->entry;
bt->entry.u.file.data_fork.lsize = tsize;
bt->entry.u.file.data_fork.psize = tsize >> HFS_SECTOR_SIZE_BITS;
bt->entry.u.file.data_fork.fork = HFS_FK_DATA;
hfs_extent_in(&bt->entry.u.file.data_fork, ext);
hfs_bnode_read(&bt->head, bt, 0, HFS_STICKY);
if (!hfs_buffer_ok(bt->head.buf)) {
goto bail2;
}
th = (struct BTHdrRec *)((char *)hfs_buffer_data(bt->head.buf) +
sizeof(struct NodeDescriptor));
/* read in the bitmap nodes (if any) */
tmp = &bt->head;
while ((next = tmp->ndFLink)) {
if (!HFS_NEW(tmp->next)) {
goto bail2;
}
hfs_bnode_read(tmp->next, bt, next, HFS_STICKY);
if (!hfs_buffer_ok(tmp->next->buf)) {
goto bail2;
}
tmp->next->prev = tmp;
tmp = tmp->next;
}
if (hfs_get_ns(th->bthNodeSize) != htons(HFS_SECTOR_SIZE)) {
hfs_warn("hfs_btree_init: bthNodeSize!=512 not supported\n");
goto bail2;
}
if (cnid == htonl(HFS_CAT_CNID)) {
bt->compare = (hfs_cmpfn)hfs_cat_compare;
} else if (cnid == htonl(HFS_EXT_CNID)) {
bt->compare = (hfs_cmpfn)hfs_ext_compare;
} else {
goto bail2;
}
bt->bthDepth = hfs_get_hs(th->bthDepth);
bt->bthRoot = hfs_get_hl(th->bthRoot);
bt->bthNRecs = hfs_get_hl(th->bthNRecs);
bt->bthFNode = hfs_get_hl(th->bthFNode);
bt->bthLNode = hfs_get_hl(th->bthLNode);
bt->bthNNodes = hfs_get_hl(th->bthNNodes);
bt->bthFree = hfs_get_hl(th->bthFree);
bt->bthKeyLen = hfs_get_hs(th->bthKeyLen);
#if defined(DEBUG_HEADER) || defined(DEBUG_ALL)
hfs_warn("bthDepth %d\n", bt->bthDepth);
hfs_warn("bthRoot %d\n", bt->bthRoot);
hfs_warn("bthNRecs %d\n", bt->bthNRecs);
hfs_warn("bthFNode %d\n", bt->bthFNode);
hfs_warn("bthLNode %d\n", bt->bthLNode);
hfs_warn("bthKeyLen %d\n", bt->bthKeyLen);
hfs_warn("bthNNodes %d\n", bt->bthNNodes);
hfs_warn("bthFree %d\n", bt->bthFree);
p = (unsigned char *)hfs_buffer_data(bt->head.buf);
q = p + HFS_SECTOR_SIZE;
while (p < q) {
hfs_warn("%02x %02x %02x %02x %02x %02x %02x %02x "
"%02x %02x %02x %02x %02x %02x %02x %02x\n",
*p++, *p++, *p++, *p++, *p++, *p++, *p++, *p++,
*p++, *p++, *p++, *p++, *p++, *p++, *p++, *p++);
}
#endif
/* Read in the root if it exists.
The header always exists, but the root exists only if the
tree is non-empty */
if (bt->bthDepth && bt->bthRoot) {
if (!HFS_NEW(bt->root)) {
goto bail2;
}
hfs_bnode_read(bt->root, bt, bt->bthRoot, HFS_STICKY);
if (!hfs_buffer_ok(bt->root->buf)) {
goto bail1;
}
} else {
bt->root = NULL;
}
return bt;
bail1:
hfs_bnode_ditch(bt->root);
bail2:
hfs_bnode_ditch(&bt->head);
HFS_DELETE(bt);
bail3:
return NULL;
}
/*
* find_ext()
*
* Given a pointer to a (struct hfs_file) and an allocation block
* number in the file, find the extent record containing that block.
* Returns a pointer to the extent record on success or NULL on failure.
* The 'cache' field of 'fil' also points to the extent so it has a
* reference count of at least 2.
*
* Callers must check that fil != NULL
*/
static struct hfs_extent * find_ext(struct hfs_fork *fork, int alloc_block)
{
struct hfs_cat_entry *entry = fork->entry;
struct hfs_btree *tr= entry->mdb->ext_tree;
struct hfs_ext_key target, *key;
struct hfs_brec brec;
struct hfs_extent *ext, *ptr;
int tmp;
if (alloc_block < 0) {
ext = &fork->first;
goto found;
}
ext = fork->cache;
if (!ext || (alloc_block < ext->start)) {
ext = &fork->first;
}
while (ext->next && (alloc_block > ext->end)) {
ext = ext->next;
}
if ((alloc_block <= ext->end) && (alloc_block >= ext->start)) {
goto found;
}
/* time to read more extents */
if (!HFS_NEW(ext)) {
goto bail3;
}
build_key(&target, fork, alloc_block);
tmp = hfs_bfind(&brec, tr, HFS_BKEY(&target), HFS_BFIND_READ_LE);
if (tmp < 0) {
goto bail2;
}
key = (struct hfs_ext_key *)brec.key;
if ((hfs_get_nl(key->FNum) != hfs_get_nl(target.FNum)) ||
(key->FkType != fork->fork)) {
goto bail1;
}
read_extent(ext, brec.data, hfs_get_hs(key->FABN));
hfs_brec_relse(&brec, NULL);
if ((alloc_block > ext->end) && (alloc_block < ext->start)) {
/* something strange happened */
goto bail2;
}
ptr = fork->cache;
if (!ptr || (alloc_block < ptr->start)) {
ptr = &fork->first;
}
while (ptr->next && (alloc_block > ptr->end)) {
ptr = ptr->next;
}
if (ext->start == ptr->start) {
/* somebody beat us to it. */
HFS_DELETE(ext);
ext = ptr;
} else if (ext->start < ptr->start) {
/* insert just before ptr */
ptr->prev->next = ext;
ext->prev = ptr->prev;
ext->next = ptr;
ptr->prev = ext;
} else {
/* insert at end */
ptr->next = ext;
ext->prev = ptr;
}
found:
++ext->count; /* for return value */
set_cache(fork, ext);
return ext;
bail1:
hfs_brec_relse(&brec, NULL);
bail2:
HFS_DELETE(ext);
bail3:
return NULL;
}
