linux-stable/fs/hfsplus/extents.c
Christoph Hellwig e349470560 hfsplus: optimize fsync
Avoid doing unessecary work in fsync.  Do nothing unless the inode
was marked dirty, and only write the various metadata inodes out if
they contain any dirty state from this inode.  This is archived by
adding three new dirty bits to the hfsplus-specific inode which are
set in the correct places.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>
2010-11-23 14:38:15 +01:00

549 lines
14 KiB
C

/*
* 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)
{
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
int res;
WARN_ON(!mutex_is_locked(&hip->extents_lock));
hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
HFSPLUS_IS_RSRC(inode) ?
HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
res = hfs_brec_find(fd);
if (hip->extent_state & HFSPLUS_EXT_NEW) {
if (res != -ENOENT)
return;
hfs_brec_insert(fd, hip->cached_extents,
sizeof(hfsplus_extent_rec));
hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
} else {
if (res)
return;
hfs_bnode_write(fd->bnode, hip->cached_extents,
fd->entryoffset, fd->entrylength);
hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
}
/*
* We can't just use hfsplus_mark_inode_dirty here, because we
* also get called from hfsplus_write_inode, which should not
* redirty the inode. Instead the callers have to be careful
* to explicily mark the inode dirty, too.
*/
set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
}
static void hfsplus_ext_write_extent_locked(struct inode *inode)
{
if (HFSPLUS_I(inode)->extent_state & HFSPLUS_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);
}
}
void hfsplus_ext_write_extent(struct inode *inode)
{
mutex_lock(&HFSPLUS_I(inode)->extents_lock);
hfsplus_ext_write_extent_locked(inode);
mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
}
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)
{
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
int res;
WARN_ON(!mutex_is_locked(&hip->extents_lock));
if (hip->extent_state & HFSPLUS_EXT_DIRTY)
__hfsplus_ext_write_extent(inode, fd);
res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
block, HFSPLUS_IS_RSRC(inode) ?
HFSPLUS_TYPE_RSRC :
HFSPLUS_TYPE_DATA);
if (!res) {
hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
hip->cached_blocks = hfsplus_ext_block_count(hip->cached_extents);
} else {
hip->cached_start = hip->cached_blocks = 0;
hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
}
return res;
}
static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
{
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
struct hfs_find_data fd;
int res;
if (block >= hip->cached_start &&
block < hip->cached_start + hip->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 = inode->i_sb;
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
int res = -EIO;
u32 ablock, dblock, mask;
int was_dirty = 0;
int shift;
/* Convert inode block to disk allocation block */
shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
ablock = iblock >> sbi->fs_shift;
if (iblock >= hip->fs_blocks) {
if (iblock > hip->fs_blocks || !create)
return -EIO;
if (ablock >= hip->alloc_blocks) {
res = hfsplus_file_extend(inode);
if (res)
return res;
}
} else
create = 0;
if (ablock < hip->first_blocks) {
dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
goto done;
}
if (inode->i_ino == HFSPLUS_EXT_CNID)
return -EIO;
mutex_lock(&hip->extents_lock);
/*
* hfsplus_ext_read_extent will write out a cached extent into
* the extents btree. In that case we may have to mark the inode
* dirty even for a pure read of an extent here.
*/
was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
res = hfsplus_ext_read_extent(inode, ablock);
if (res) {
mutex_unlock(&hip->extents_lock);
return -EIO;
}
dblock = hfsplus_ext_find_block(hip->cached_extents,
ablock - hip->cached_start);
mutex_unlock(&hip->extents_lock);
done:
dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
mask = (1 << sbi->fs_shift) - 1;
map_bh(bh_result, sb, (dblock << sbi->fs_shift) + sbi->blockoffset + (iblock & mask));
if (create) {
set_buffer_new(bh_result);
hip->phys_size += sb->s_blocksize;
hip->fs_blocks++;
inode_add_bytes(inode, sb->s_blocksize);
}
if (create || was_dirty)
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;
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
u32 start, len, goal;
int res;
if (sbi->alloc_file->i_size * 8 <
sbi->total_blocks - sbi->free_blocks + 8) {
// extend alloc file
printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n",
sbi->alloc_file->i_size * 8,
sbi->total_blocks, sbi->free_blocks);
return -ENOSPC;
}
mutex_lock(&hip->extents_lock);
if (hip->alloc_blocks == hip->first_blocks)
goal = hfsplus_ext_lastblock(hip->first_extents);
else {
res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
if (res)
goto out;
goal = hfsplus_ext_lastblock(hip->cached_extents);
}
len = hip->clump_blocks;
start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
if (start >= sbi->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 (hip->alloc_blocks <= hip->first_blocks) {
if (!hip->first_blocks) {
dprint(DBG_EXTENT, "first extents\n");
/* no extents yet */
hip->first_extents[0].start_block = cpu_to_be32(start);
hip->first_extents[0].block_count = cpu_to_be32(len);
res = 0;
} else {
/* try to append to extents in inode */
res = hfsplus_add_extent(hip->first_extents,
hip->alloc_blocks,
start, len);
if (res == -ENOSPC)
goto insert_extent;
}
if (!res) {
hfsplus_dump_extent(hip->first_extents);
hip->first_blocks += len;
}
} else {
res = hfsplus_add_extent(hip->cached_extents,
hip->alloc_blocks - hip->cached_start,
start, len);
if (!res) {
hfsplus_dump_extent(hip->cached_extents);
hip->extent_state |= HFSPLUS_EXT_DIRTY;
hip->cached_blocks += len;
} else if (res == -ENOSPC)
goto insert_extent;
}
out:
mutex_unlock(&hip->extents_lock);
if (!res) {
hip->alloc_blocks += len;
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
}
return res;
insert_extent:
dprint(DBG_EXTENT, "insert new extent\n");
hfsplus_ext_write_extent_locked(inode);
memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
hip->cached_extents[0].start_block = cpu_to_be32(start);
hip->cached_extents[0].block_count = cpu_to_be32(len);
hfsplus_dump_extent(hip->cached_extents);
hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
hip->cached_start = hip->alloc_blocks;
hip->cached_blocks = len;
res = 0;
goto out;
}
void hfsplus_file_truncate(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
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)hip->phys_size, inode->i_size);
if (inode->i_size > hip->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 == hip->phys_size)
return;
blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
HFSPLUS_SB(sb)->alloc_blksz_shift;
alloc_cnt = hip->alloc_blocks;
if (blk_cnt == alloc_cnt)
goto out;
mutex_lock(&hip->extents_lock);
hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
while (1) {
if (alloc_cnt == hip->first_blocks) {
hfsplus_free_extents(sb, hip->first_extents,
alloc_cnt, alloc_cnt - blk_cnt);
hfsplus_dump_extent(hip->first_extents);
hip->first_blocks = blk_cnt;
break;
}
res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
if (res)
break;
start = hip->cached_start;
hfsplus_free_extents(sb, hip->cached_extents,
alloc_cnt - start, alloc_cnt - blk_cnt);
hfsplus_dump_extent(hip->cached_extents);
if (blk_cnt > start) {
hip->extent_state |= HFSPLUS_EXT_DIRTY;
break;
}
alloc_cnt = start;
hip->cached_start = hip->cached_blocks = 0;
hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
hfs_brec_remove(&fd);
}
hfs_find_exit(&fd);
mutex_unlock(&hip->extents_lock);
hip->alloc_blocks = blk_cnt;
out:
hip->phys_size = inode->i_size;
hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
}