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DEFINITIONS
This source file includes following definitions.
- hfsplus_ext_cmp_key
- hfsplus_ext_build_key
- hfsplus_ext_find_block
- hfsplus_ext_block_count
- hfsplus_ext_lastblock
- __hfsplus_ext_write_extent
- hfsplus_ext_write_extent
- __hfsplus_ext_read_extent
- __hfsplus_ext_cache_extent
- hfsplus_ext_read_extent
- hfsplus_get_block
- hfsplus_dump_extent
- hfsplus_add_extent
- hfsplus_free_extents
- hfsplus_free_fork
- hfsplus_file_extend
- hfsplus_file_truncate
/*
* linux/fs/hfsplus/extents.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
* Handling of Extents both in catalog and extents overflow trees
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
/* Compare two extents keys, returns 0 on same, pos/neg for difference */
int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
const hfsplus_btree_key *k2)
{
__be32 k1id, k2id;
__be32 k1s, k2s;
k1id = k1->ext.cnid;
k2id = k2->ext.cnid;
if (k1id != k2id)
return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
if (k1->ext.fork_type != k2->ext.fork_type)
return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
k1s = k1->ext.start_block;
k2s = k2->ext.start_block;
if (k1s == k2s)
return 0;
return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
}
static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
u32 block, u8 type)
{
key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
key->ext.cnid = cpu_to_be32(cnid);
key->ext.start_block = cpu_to_be32(block);
key->ext.fork_type = type;
key->ext.pad = 0;
}
static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
{
int i;
u32 count;
for (i = 0; i < 8; ext++, i++) {
count = be32_to_cpu(ext->block_count);
if (off < count)
return be32_to_cpu(ext->start_block) + off;
off -= count;
}
/* panic? */
return 0;
}
static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
{
int i;
u32 count = 0;
for (i = 0; i < 8; ext++, i++)
count += be32_to_cpu(ext->block_count);
return count;
}
static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
{
int i;
ext += 7;
for (i = 0; i < 7; ext--, i++)
if (ext->block_count)
break;
return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
}
static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
{
int res;
hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start,
HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
res = hfs_brec_find(fd);
if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) {
if (res != -ENOENT)
return;
hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec));
HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
} else {
if (res)
return;
hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength);
HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY;
}
}
void hfsplus_ext_write_extent(struct inode *inode)
{
if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) {
struct hfs_find_data fd;
hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
__hfsplus_ext_write_extent(inode, &fd);
hfs_find_exit(&fd);
}
}
static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
struct hfsplus_extent *extent,
u32 cnid, u32 block, u8 type)
{
int res;
hfsplus_ext_build_key(fd->search_key, cnid, block, type);
fd->key->ext.cnid = 0;
res = hfs_brec_find(fd);
if (res && res != -ENOENT)
return res;
if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
fd->key->ext.fork_type != fd->search_key->ext.fork_type)
return -ENOENT;
if (fd->entrylength != sizeof(hfsplus_extent_rec))
return -EIO;
hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
return 0;
}
static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
{
int res;
if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY)
__hfsplus_ext_write_extent(inode, fd);
res = __hfsplus_ext_read_extent(fd, HFSPLUS_I(inode).cached_extents, inode->i_ino,
block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
if (!res) {
HFSPLUS_I(inode).cached_start = be32_to_cpu(fd->key->ext.start_block);
HFSPLUS_I(inode).cached_blocks = hfsplus_ext_block_count(HFSPLUS_I(inode).cached_extents);
} else {
HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
}
return res;
}
static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
{
struct hfs_find_data fd;
int res;
if (block >= HFSPLUS_I(inode).cached_start &&
block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks)
return 0;
hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
res = __hfsplus_ext_cache_extent(&fd, inode, block);
hfs_find_exit(&fd);
return res;
}
/* Get a block at iblock for inode, possibly allocating if create */
int hfsplus_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct super_block *sb;
int res = -EIO;
u32 ablock, dblock, mask;
int shift;
sb = inode->i_sb;
/* Convert inode block to disk allocation block */
shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits;
ablock = iblock >> HFSPLUS_SB(sb).fs_shift;
if (iblock >= HFSPLUS_I(inode).fs_blocks) {
if (iblock > HFSPLUS_I(inode).fs_blocks || !create)
return -EIO;
if (ablock >= HFSPLUS_I(inode).alloc_blocks) {
res = hfsplus_file_extend(inode);
if (res)
return res;
}
} else
create = 0;
if (ablock < HFSPLUS_I(inode).first_blocks) {
dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock);
goto done;
}
mutex_lock(&HFSPLUS_I(inode).extents_lock);
res = hfsplus_ext_read_extent(inode, ablock);
if (!res) {
dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
HFSPLUS_I(inode).cached_start);
} else {
mutex_unlock(&HFSPLUS_I(inode).extents_lock);
return -EIO;
}
mutex_unlock(&HFSPLUS_I(inode).extents_lock);
done:
dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
if (create) {
set_buffer_new(bh_result);
HFSPLUS_I(inode).phys_size += sb->s_blocksize;
HFSPLUS_I(inode).fs_blocks++;
inode_add_bytes(inode, sb->s_blocksize);
mark_inode_dirty(inode);
}
return 0;
}
static void hfsplus_dump_extent(struct hfsplus_extent *extent)
{
int i;
dprint(DBG_EXTENT, " ");
for (i = 0; i < 8; i++)
dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
be32_to_cpu(extent[i].block_count));
dprint(DBG_EXTENT, "\n");
}
static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
u32 alloc_block, u32 block_count)
{
u32 count, start;
int i;
hfsplus_dump_extent(extent);
for (i = 0; i < 8; extent++, i++) {
count = be32_to_cpu(extent->block_count);
if (offset == count) {
start = be32_to_cpu(extent->start_block);
if (alloc_block != start + count) {
if (++i >= 8)
return -ENOSPC;
extent++;
extent->start_block = cpu_to_be32(alloc_block);
} else
block_count += count;
extent->block_count = cpu_to_be32(block_count);
return 0;
} else if (offset < count)
break;
offset -= count;
}
/* panic? */
return -EIO;
}
static int hfsplus_free_extents(struct super_block *sb,
struct hfsplus_extent *extent,
u32 offset, u32 block_nr)
{
u32 count, start;
int i;
hfsplus_dump_extent(extent);
for (i = 0; i < 8; extent++, i++) {
count = be32_to_cpu(extent->block_count);
if (offset == count)
goto found;
else if (offset < count)
break;
offset -= count;
}
/* panic? */
return -EIO;
found:
for (;;) {
start = be32_to_cpu(extent->start_block);
if (count <= block_nr) {
hfsplus_block_free(sb, start, count);
extent->block_count = 0;
extent->start_block = 0;
block_nr -= count;
} else {
count -= block_nr;
hfsplus_block_free(sb, start + count, block_nr);
extent->block_count = cpu_to_be32(count);
block_nr = 0;
}
if (!block_nr || !i)
return 0;
i--;
extent--;
count = be32_to_cpu(extent->block_count);
}
}
int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type)
{
struct hfs_find_data fd;
hfsplus_extent_rec ext_entry;
u32 total_blocks, blocks, start;
int res, i;
total_blocks = be32_to_cpu(fork->total_blocks);
if (!total_blocks)
return 0;
blocks = 0;
for (i = 0; i < 8; i++)
blocks += be32_to_cpu(fork->extents[i].block_count);
res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
if (res)
return res;
if (total_blocks == blocks)
return 0;
hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
do {
res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
total_blocks, type);
if (res)
break;
start = be32_to_cpu(fd.key->ext.start_block);
hfsplus_free_extents(sb, ext_entry,
total_blocks - start,
total_blocks);
hfs_brec_remove(&fd);
total_blocks = start;
} while (total_blocks > blocks);
hfs_find_exit(&fd);
return res;
}
int hfsplus_file_extend(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
u32 start, len, goal;
int res;
if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
// extend alloc file
printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8,
HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks);
return -ENOSPC;
}
mutex_lock(&HFSPLUS_I(inode).extents_lock);
if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
else {
res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
if (res)
goto out;
goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
}
len = HFSPLUS_I(inode).clump_blocks;
start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len);
if (start >= HFSPLUS_SB(sb).total_blocks) {
start = hfsplus_block_allocate(sb, goal, 0, &len);
if (start >= goal) {
res = -ENOSPC;
goto out;
}
}
dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) {
if (!HFSPLUS_I(inode).first_blocks) {
dprint(DBG_EXTENT, "first extents\n");
/* no extents yet */
HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start);
HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len);
res = 0;
} else {
/* try to append to extents in inode */
res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents,
HFSPLUS_I(inode).alloc_blocks,
start, len);
if (res == -ENOSPC)
goto insert_extent;
}
if (!res) {
hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
HFSPLUS_I(inode).first_blocks += len;
}
} else {
res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents,
HFSPLUS_I(inode).alloc_blocks -
HFSPLUS_I(inode).cached_start,
start, len);
if (!res) {
hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
HFSPLUS_I(inode).cached_blocks += len;
} else if (res == -ENOSPC)
goto insert_extent;
}
out:
mutex_unlock(&HFSPLUS_I(inode).extents_lock);
if (!res) {
HFSPLUS_I(inode).alloc_blocks += len;
mark_inode_dirty(inode);
}
return res;
insert_extent:
dprint(DBG_EXTENT, "insert new extent\n");
hfsplus_ext_write_extent(inode);
memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec));
HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start);
HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len);
hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW;
HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks;
HFSPLUS_I(inode).cached_blocks = len;
res = 0;
goto out;
}
void hfsplus_file_truncate(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct hfs_find_data fd;
u32 alloc_cnt, blk_cnt, start;
int res;
dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
(long long)HFSPLUS_I(inode).phys_size, inode->i_size);
if (inode->i_size > HFSPLUS_I(inode).phys_size) {
struct address_space *mapping = inode->i_mapping;
struct page *page;
void *fsdata;
u32 size = inode->i_size;
int res;
res = pagecache_write_begin(NULL, mapping, size, 0,
AOP_FLAG_UNINTERRUPTIBLE,
&page, &fsdata);
if (res)
return;
res = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata);
if (res < 0)
return;
mark_inode_dirty(inode);
return;
} else if (inode->i_size == HFSPLUS_I(inode).phys_size)
return;
blk_cnt = (inode->i_size + HFSPLUS_SB(sb).alloc_blksz - 1) >> HFSPLUS_SB(sb).alloc_blksz_shift;
alloc_cnt = HFSPLUS_I(inode).alloc_blocks;
if (blk_cnt == alloc_cnt)
goto out;
mutex_lock(&HFSPLUS_I(inode).extents_lock);
hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
while (1) {
if (alloc_cnt == HFSPLUS_I(inode).first_blocks) {
hfsplus_free_extents(sb, HFSPLUS_I(inode).first_extents,
alloc_cnt, alloc_cnt - blk_cnt);
hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
HFSPLUS_I(inode).first_blocks = blk_cnt;
break;
}
res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
if (res)
break;
start = HFSPLUS_I(inode).cached_start;
hfsplus_free_extents(sb, HFSPLUS_I(inode).cached_extents,
alloc_cnt - start, alloc_cnt - blk_cnt);
hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
if (blk_cnt > start) {
HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
break;
}
alloc_cnt = start;
HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
hfs_brec_remove(&fd);
}
hfs_find_exit(&fd);
mutex_unlock(&HFSPLUS_I(inode).extents_lock);
HFSPLUS_I(inode).alloc_blocks = blk_cnt;
out:
HFSPLUS_I(inode).phys_size = inode->i_size;
HFSPLUS_I(inode).fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
inode_set_bytes(inode, HFSPLUS_I(inode).fs_blocks << sb->s_blocksize_bits);
mark_inode_dirty(inode);
}