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![Eric Sesterhenn](/assets/img/avatar_default.png)
A corrupted extent for the extent file itself may try to get an impossible extent, causing a deadlock if I see it correctly. Check the inode number after the first_blocks checks and fail if it's the extent file, as according to the spec the extent file should have no extent for itself. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
506 lines
14 KiB
C
506 lines
14 KiB
C
/*
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* linux/fs/hfsplus/extents.c
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*
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* Copyright (C) 2001
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* Brad Boyer (flar@allandria.com)
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* (C) 2003 Ardis Technologies <roman@ardistech.com>
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*
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* Handling of Extents both in catalog and extents overflow trees
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*/
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include "hfsplus_fs.h"
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#include "hfsplus_raw.h"
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/* Compare two extents keys, returns 0 on same, pos/neg for difference */
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int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
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const hfsplus_btree_key *k2)
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{
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__be32 k1id, k2id;
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__be32 k1s, k2s;
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k1id = k1->ext.cnid;
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k2id = k2->ext.cnid;
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if (k1id != k2id)
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return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
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if (k1->ext.fork_type != k2->ext.fork_type)
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return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
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k1s = k1->ext.start_block;
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k2s = k2->ext.start_block;
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if (k1s == k2s)
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return 0;
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return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
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}
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static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
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u32 block, u8 type)
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{
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key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
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key->ext.cnid = cpu_to_be32(cnid);
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key->ext.start_block = cpu_to_be32(block);
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key->ext.fork_type = type;
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key->ext.pad = 0;
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}
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static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
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{
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int i;
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u32 count;
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for (i = 0; i < 8; ext++, i++) {
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count = be32_to_cpu(ext->block_count);
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if (off < count)
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return be32_to_cpu(ext->start_block) + off;
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off -= count;
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}
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/* panic? */
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return 0;
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}
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static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
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{
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int i;
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u32 count = 0;
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for (i = 0; i < 8; ext++, i++)
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count += be32_to_cpu(ext->block_count);
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return count;
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}
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static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
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{
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int i;
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ext += 7;
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for (i = 0; i < 7; ext--, i++)
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if (ext->block_count)
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break;
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return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
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}
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static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
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{
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int res;
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hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start,
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HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
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res = hfs_brec_find(fd);
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if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) {
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if (res != -ENOENT)
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return;
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hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec));
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HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
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} else {
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if (res)
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return;
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hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength);
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HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY;
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}
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}
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void hfsplus_ext_write_extent(struct inode *inode)
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{
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if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) {
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struct hfs_find_data fd;
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hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
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__hfsplus_ext_write_extent(inode, &fd);
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hfs_find_exit(&fd);
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}
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}
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static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
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struct hfsplus_extent *extent,
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u32 cnid, u32 block, u8 type)
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{
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int res;
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hfsplus_ext_build_key(fd->search_key, cnid, block, type);
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fd->key->ext.cnid = 0;
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res = hfs_brec_find(fd);
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if (res && res != -ENOENT)
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return res;
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if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
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fd->key->ext.fork_type != fd->search_key->ext.fork_type)
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return -ENOENT;
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if (fd->entrylength != sizeof(hfsplus_extent_rec))
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return -EIO;
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hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
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return 0;
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}
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static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
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{
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int res;
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if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY)
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__hfsplus_ext_write_extent(inode, fd);
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res = __hfsplus_ext_read_extent(fd, HFSPLUS_I(inode).cached_extents, inode->i_ino,
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block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
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if (!res) {
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HFSPLUS_I(inode).cached_start = be32_to_cpu(fd->key->ext.start_block);
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HFSPLUS_I(inode).cached_blocks = hfsplus_ext_block_count(HFSPLUS_I(inode).cached_extents);
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} else {
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HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
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HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
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}
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return res;
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}
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static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
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{
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struct hfs_find_data fd;
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int res;
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if (block >= HFSPLUS_I(inode).cached_start &&
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block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks)
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return 0;
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hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
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res = __hfsplus_ext_cache_extent(&fd, inode, block);
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hfs_find_exit(&fd);
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return res;
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}
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/* Get a block at iblock for inode, possibly allocating if create */
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int hfsplus_get_block(struct inode *inode, sector_t iblock,
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struct buffer_head *bh_result, int create)
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{
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struct super_block *sb;
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int res = -EIO;
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u32 ablock, dblock, mask;
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int shift;
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sb = inode->i_sb;
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/* Convert inode block to disk allocation block */
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shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits;
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ablock = iblock >> HFSPLUS_SB(sb).fs_shift;
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if (iblock >= HFSPLUS_I(inode).fs_blocks) {
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if (iblock > HFSPLUS_I(inode).fs_blocks || !create)
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return -EIO;
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if (ablock >= HFSPLUS_I(inode).alloc_blocks) {
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res = hfsplus_file_extend(inode);
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if (res)
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return res;
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}
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} else
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create = 0;
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if (ablock < HFSPLUS_I(inode).first_blocks) {
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dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock);
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goto done;
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}
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if (inode->i_ino == HFSPLUS_EXT_CNID)
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return -EIO;
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mutex_lock(&HFSPLUS_I(inode).extents_lock);
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res = hfsplus_ext_read_extent(inode, ablock);
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if (!res) {
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dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
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HFSPLUS_I(inode).cached_start);
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} else {
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mutex_unlock(&HFSPLUS_I(inode).extents_lock);
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return -EIO;
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}
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mutex_unlock(&HFSPLUS_I(inode).extents_lock);
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done:
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dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
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mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
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map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
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if (create) {
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set_buffer_new(bh_result);
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HFSPLUS_I(inode).phys_size += sb->s_blocksize;
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HFSPLUS_I(inode).fs_blocks++;
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inode_add_bytes(inode, sb->s_blocksize);
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mark_inode_dirty(inode);
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}
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return 0;
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}
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static void hfsplus_dump_extent(struct hfsplus_extent *extent)
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{
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int i;
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dprint(DBG_EXTENT, " ");
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for (i = 0; i < 8; i++)
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dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
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be32_to_cpu(extent[i].block_count));
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dprint(DBG_EXTENT, "\n");
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}
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static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
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u32 alloc_block, u32 block_count)
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{
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u32 count, start;
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int i;
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hfsplus_dump_extent(extent);
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for (i = 0; i < 8; extent++, i++) {
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count = be32_to_cpu(extent->block_count);
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if (offset == count) {
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start = be32_to_cpu(extent->start_block);
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if (alloc_block != start + count) {
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if (++i >= 8)
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return -ENOSPC;
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extent++;
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extent->start_block = cpu_to_be32(alloc_block);
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} else
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block_count += count;
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extent->block_count = cpu_to_be32(block_count);
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return 0;
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} else if (offset < count)
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break;
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offset -= count;
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}
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/* panic? */
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return -EIO;
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}
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static int hfsplus_free_extents(struct super_block *sb,
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struct hfsplus_extent *extent,
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u32 offset, u32 block_nr)
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{
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u32 count, start;
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int i;
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hfsplus_dump_extent(extent);
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for (i = 0; i < 8; extent++, i++) {
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count = be32_to_cpu(extent->block_count);
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if (offset == count)
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goto found;
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else if (offset < count)
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break;
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offset -= count;
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}
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/* panic? */
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return -EIO;
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found:
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for (;;) {
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start = be32_to_cpu(extent->start_block);
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if (count <= block_nr) {
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hfsplus_block_free(sb, start, count);
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extent->block_count = 0;
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extent->start_block = 0;
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block_nr -= count;
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} else {
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count -= block_nr;
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hfsplus_block_free(sb, start + count, block_nr);
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extent->block_count = cpu_to_be32(count);
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block_nr = 0;
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}
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if (!block_nr || !i)
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return 0;
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i--;
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extent--;
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count = be32_to_cpu(extent->block_count);
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}
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}
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int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type)
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{
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struct hfs_find_data fd;
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hfsplus_extent_rec ext_entry;
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u32 total_blocks, blocks, start;
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int res, i;
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total_blocks = be32_to_cpu(fork->total_blocks);
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if (!total_blocks)
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return 0;
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blocks = 0;
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for (i = 0; i < 8; i++)
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blocks += be32_to_cpu(fork->extents[i].block_count);
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res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
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if (res)
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return res;
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if (total_blocks == blocks)
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return 0;
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hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
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do {
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res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
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total_blocks, type);
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if (res)
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break;
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start = be32_to_cpu(fd.key->ext.start_block);
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hfsplus_free_extents(sb, ext_entry,
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total_blocks - start,
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total_blocks);
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hfs_brec_remove(&fd);
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total_blocks = start;
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} while (total_blocks > blocks);
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hfs_find_exit(&fd);
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return res;
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}
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int hfsplus_file_extend(struct inode *inode)
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{
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struct super_block *sb = inode->i_sb;
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u32 start, len, goal;
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int res;
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if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
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// extend alloc file
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printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8,
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HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks);
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return -ENOSPC;
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}
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mutex_lock(&HFSPLUS_I(inode).extents_lock);
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if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
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goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
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else {
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res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
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if (res)
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goto out;
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goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
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}
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len = HFSPLUS_I(inode).clump_blocks;
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start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len);
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if (start >= HFSPLUS_SB(sb).total_blocks) {
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start = hfsplus_block_allocate(sb, goal, 0, &len);
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if (start >= goal) {
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res = -ENOSPC;
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goto out;
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}
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}
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dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
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if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) {
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if (!HFSPLUS_I(inode).first_blocks) {
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dprint(DBG_EXTENT, "first extents\n");
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/* no extents yet */
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HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start);
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HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len);
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res = 0;
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} else {
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/* try to append to extents in inode */
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res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents,
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HFSPLUS_I(inode).alloc_blocks,
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start, len);
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if (res == -ENOSPC)
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goto insert_extent;
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}
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if (!res) {
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hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
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HFSPLUS_I(inode).first_blocks += len;
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}
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} else {
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res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents,
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HFSPLUS_I(inode).alloc_blocks -
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HFSPLUS_I(inode).cached_start,
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start, len);
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if (!res) {
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hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
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HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
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HFSPLUS_I(inode).cached_blocks += len;
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} else if (res == -ENOSPC)
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goto insert_extent;
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}
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out:
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mutex_unlock(&HFSPLUS_I(inode).extents_lock);
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if (!res) {
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HFSPLUS_I(inode).alloc_blocks += len;
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mark_inode_dirty(inode);
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}
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return res;
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insert_extent:
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dprint(DBG_EXTENT, "insert new extent\n");
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hfsplus_ext_write_extent(inode);
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memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec));
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HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start);
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HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len);
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hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
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HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW;
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HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks;
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HFSPLUS_I(inode).cached_blocks = len;
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res = 0;
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goto out;
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}
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void hfsplus_file_truncate(struct inode *inode)
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{
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struct super_block *sb = inode->i_sb;
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struct hfs_find_data fd;
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u32 alloc_cnt, blk_cnt, start;
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int res;
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|
|
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);
|
|
}
|