001-squashfs.patch

来自「Linux Home Server 是专门为家庭和SOHO/SMB 设计的高性价」· PATCH 代码 · 共 2,252 行 · 第 1/5 页

+			up(&msblk->block_cache_mutex);
+			continue;
+		}
+
+		if ((bytes = msblk->block_cache[i].length - offset) >= length) {
+			if (buffer)
+				memcpy(buffer, msblk->block_cache[i].data +
+						offset, length);
+			if (msblk->block_cache[i].length - offset == length) {
+				*next_block = msblk->block_cache[i].next_index;
+				*next_offset = 0;
+			} else {
+				*next_block = block;
+				*next_offset = offset + length;
+			}
+			up(&msblk->block_cache_mutex);
+			goto finish;
+		} else {
+			if (buffer) {
+				memcpy(buffer, msblk->block_cache[i].data +
+						offset, bytes);
+				buffer += bytes;
+			}
+			block = msblk->block_cache[i].next_index;
+			up(&msblk->block_cache_mutex);
+			length -= bytes;
+			offset = 0;
+		}
+	}
+
+finish:
+	return return_length;
+out:
+	return 0;
+}
+
+
+static int get_fragment_location(struct super_block *s, unsigned int fragment,
+				long long *fragment_start_block,
+				unsigned int *fragment_size)
+{
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	long long start_block =
+		msblk->fragment_index[SQUASHFS_FRAGMENT_INDEX(fragment)];
+	int offset = SQUASHFS_FRAGMENT_INDEX_OFFSET(fragment);
+	struct squashfs_fragment_entry fragment_entry;
+
+	if (msblk->swap) {
+		struct squashfs_fragment_entry sfragment_entry;
+
+		if (!squashfs_get_cached_block(s, (char *) &sfragment_entry,
+					start_block, offset,
+					sizeof(sfragment_entry), &start_block,
+					&offset))
+			goto out;
+		SQUASHFS_SWAP_FRAGMENT_ENTRY(&fragment_entry, &sfragment_entry);
+	} else
+		if (!squashfs_get_cached_block(s, (char *) &fragment_entry,
+					start_block, offset,
+					sizeof(fragment_entry), &start_block,
+					&offset))
+			goto out;
+
+	*fragment_start_block = fragment_entry.start_block;
+	*fragment_size = fragment_entry.size;
+
+	return 1;
+
+out:
+	return 0;
+}
+
+
+SQSH_EXTERN void release_cached_fragment(struct squashfs_sb_info *msblk, struct
+					squashfs_fragment_cache *fragment)
+{
+	down(&msblk->fragment_mutex);
+	fragment->locked --;
+	wake_up(&msblk->fragment_wait_queue);
+	up(&msblk->fragment_mutex);
+}
+
+
+SQSH_EXTERN struct squashfs_fragment_cache *get_cached_fragment(struct super_block
+					*s, long long start_block,
+					int length)
+{
+	int i, n;
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+
+	while ( 1 ) {
+		down(&msblk->fragment_mutex);
+
+		for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS &&
+				msblk->fragment[i].block != start_block; i++);
+
+		if (i == SQUASHFS_CACHED_FRAGMENTS) {
+			for (i = msblk->next_fragment, n =
+				SQUASHFS_CACHED_FRAGMENTS; n &&
+				msblk->fragment[i].locked; n--, i = (i + 1) %
+				SQUASHFS_CACHED_FRAGMENTS);
+
+			if (n == 0) {
+				wait_queue_t wait;
+
+				init_waitqueue_entry(&wait, current);
+				add_wait_queue(&msblk->fragment_wait_queue,
+									&wait);
+				set_current_state(TASK_UNINTERRUPTIBLE);
+				up(&msblk->fragment_mutex);
+				schedule();
+				set_current_state(TASK_RUNNING);
+				remove_wait_queue(&msblk->fragment_wait_queue,
+									&wait);
+				continue;
+			}
+			msblk->next_fragment = (msblk->next_fragment + 1) %
+				SQUASHFS_CACHED_FRAGMENTS;
+
+			if (msblk->fragment[i].data == NULL)
+				if (!(msblk->fragment[i].data = SQUASHFS_ALLOC
+						(SQUASHFS_FILE_MAX_SIZE))) {
+					ERROR("Failed to allocate fragment "
+							"cache block\n");
+					up(&msblk->fragment_mutex);
+					goto out;
+				}
+
+			msblk->fragment[i].block = SQUASHFS_INVALID_BLK;
+			msblk->fragment[i].locked = 1;
+			up(&msblk->fragment_mutex);
+
+			if (!(msblk->fragment[i].length = squashfs_read_data(s,
+						msblk->fragment[i].data,
+						start_block, length, NULL))) {
+				ERROR("Unable to read fragment cache block "
+							"[%llx]\n", start_block);
+				msblk->fragment[i].locked = 0;
+				goto out;
+			}
+
+			msblk->fragment[i].block = start_block;
+			TRACE("New fragment %d, start block %lld, locked %d\n",
+						i, msblk->fragment[i].block,
+						msblk->fragment[i].locked);
+			break;
+		}
+
+		msblk->fragment[i].locked++;
+		up(&msblk->fragment_mutex);
+		TRACE("Got fragment %d, start block %lld, locked %d\n", i,
+						msblk->fragment[i].block,
+						msblk->fragment[i].locked);
+		break;
+	}
+
+	return &msblk->fragment[i];
+
+out:
+	return NULL;
+}
+
+
+static struct inode *squashfs_new_inode(struct super_block *s,
+		struct squashfs_base_inode_header *inodeb)
+{
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	struct inode *i = new_inode(s);
+
+	if (i) {
+		i->i_ino = inodeb->inode_number;
+		i->i_mtime.tv_sec = inodeb->mtime;
+		i->i_atime.tv_sec = inodeb->mtime;
+		i->i_ctime.tv_sec = inodeb->mtime;
+		i->i_uid = msblk->uid[inodeb->uid];
+		i->i_mode = inodeb->mode;
+		i->i_size = 0;
+		if (inodeb->guid == SQUASHFS_GUIDS)
+			i->i_gid = i->i_uid;
+		else
+			i->i_gid = msblk->guid[inodeb->guid];
+	}
+
+	return i;
+}
+
+
+static struct inode *squashfs_iget(struct super_block *s, squashfs_inode_t inode)
+{
+	struct inode *i;
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	struct squashfs_super_block *sblk = &msblk->sblk;
+	long long block = SQUASHFS_INODE_BLK(inode) +
+		sblk->inode_table_start;
+	unsigned int offset = SQUASHFS_INODE_OFFSET(inode);
+	long long next_block;
+	unsigned int next_offset;
+	union squashfs_inode_header id, sid;
+	struct squashfs_base_inode_header *inodeb = &id.base,
+					  *sinodeb = &sid.base;
+
+	TRACE("Entered squashfs_iget\n");
+
+	if (msblk->swap) {
+		if (!squashfs_get_cached_block(s, (char *) sinodeb, block,
+					offset, sizeof(*sinodeb), &next_block,
+					&next_offset))
+			goto failed_read;
+		SQUASHFS_SWAP_BASE_INODE_HEADER(inodeb, sinodeb,
+					sizeof(*sinodeb));
+	} else
+		if (!squashfs_get_cached_block(s, (char *) inodeb, block,
+					offset, sizeof(*inodeb), &next_block,
+					&next_offset))
+			goto failed_read;
+
+	switch(inodeb->inode_type) {
+		case SQUASHFS_FILE_TYPE: {
+			unsigned int frag_size;
+			long long frag_blk;
+			struct squashfs_reg_inode_header *inodep = &id.reg;
+			struct squashfs_reg_inode_header *sinodep = &sid.reg;
+
+			if (msblk->swap) {
+				if (!squashfs_get_cached_block(s, (char *)
+						sinodep, block, offset,
+						sizeof(*sinodep), &next_block,
+						&next_offset))
+					goto failed_read;
+				SQUASHFS_SWAP_REG_INODE_HEADER(inodep, sinodep);
+			} else
+				if (!squashfs_get_cached_block(s, (char *)
+						inodep, block, offset,
+						sizeof(*inodep), &next_block,
+						&next_offset))
+					goto failed_read;
+
+			frag_blk = SQUASHFS_INVALID_BLK;
+			if (inodep->fragment != SQUASHFS_INVALID_FRAG &&
+					!get_fragment_location(s,
+					inodep->fragment, &frag_blk, &frag_size))
+				goto failed_read;
+
+			if((i = squashfs_new_inode(s, inodeb)) == NULL)
+				goto failed_read1;
+
+			i->i_nlink = 1;
+			i->i_size = inodep->file_size;
+			i->i_fop = &generic_ro_fops;
+			i->i_mode |= S_IFREG;
+			i->i_blocks = ((i->i_size - 1) >> 9) + 1;
+			SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk;
+			SQUASHFS_I(i)->u.s1.fragment_size = frag_size;
+			SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset;
+			SQUASHFS_I(i)->start_block = inodep->start_block;
+			SQUASHFS_I(i)->u.s1.block_list_start = next_block;
+			SQUASHFS_I(i)->offset = next_offset;
+			if (sblk->block_size > 4096)
+				i->i_data.a_ops = &squashfs_aops;
+			else
+				i->i_data.a_ops = &squashfs_aops_4K;
+
+			TRACE("File inode %x:%x, start_block %llx, "
+					"block_list_start %llx, offset %x\n",
+					SQUASHFS_INODE_BLK(inode), offset,
+					inodep->start_block, next_block,
+					next_offset);
+			break;
+		}
+		case SQUASHFS_LREG_TYPE: {
+			unsigned int frag_size;
+			long long frag_blk;
+			struct squashfs_lreg_inode_header *inodep = &id.lreg;
+			struct squashfs_lreg_inode_header *sinodep = &sid.lreg;
+
+			if (msblk->swap) {
+				if (!squashfs_get_cached_block(s, (char *)
+						sinodep, block, offset,
+						sizeof(*sinodep), &next_block,
+						&next_offset))
+					goto failed_read;
+				SQUASHFS_SWAP_LREG_INODE_HEADER(inodep, sinodep);
+			} else
+				if (!squashfs_get_cached_block(s, (char *)
+						inodep, block, offset,
+						sizeof(*inodep), &next_block,
+						&next_offset))
+					goto failed_read;
+
+			frag_blk = SQUASHFS_INVALID_BLK;
+			if (inodep->fragment != SQUASHFS_INVALID_FRAG &&
+					!get_fragment_location(s,
+					inodep->fragment, &frag_blk, &frag_size))
+				goto failed_read;
+
+			if((i = squashfs_new_inode(s, inodeb)) == NULL)
+				goto failed_read1;
+
+			i->i_nlink = inodep->nlink;
+			i->i_size = inodep->file_size;
+			i->i_fop = &generic_ro_fops;
+			i->i_mode |= S_IFREG;
+			i->i_blocks = ((i->i_size - 1) >> 9) + 1;
+			SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk;
+			SQUASHFS_I(i)->u.s1.fragment_size = frag_size;
+			SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset;
+			SQUASHFS_I(i)->start_block = inodep->start_block;
+			SQUASHFS_I(i)->u.s1.block_list_start = next_block;
+			SQUASHFS_I(i)->offset = next_offset;
+			if (sblk->block_size > 4096)
+				i->i_data.a_ops = &squashfs_aops;
+			else
+				i->i_data.a_ops = &squashfs_aops_4K;
+
+			TRACE("File inode %x:%x, start_block %llx, "
+					"block_list_start %llx, offset %x\n",
+					SQUASHFS_INODE_BLK(inode), offset,
+					inodep->start_block, next_block,
+					next_offset);
+			break;
+		}
+		case SQUASHFS_DIR_TYPE: {
+			struct squashfs_dir_inode_header *inodep = &id.dir;
+			struct squashfs_dir_inode_header *sinodep = &sid.dir;
+
+			if (msblk->swap) {
+				if (!squashfs_get_cached_block(s, (char *)
+						sinodep, block, offset,
+						sizeof(*sinodep), &next_block,
+						&next_offset))
+					goto failed_read;
+				SQUASHFS_SWAP_DIR_INODE_HEADER(inodep, sinodep);
+			} else
+				if (!squashfs_get_cached_block(s, (char *)
+						inodep, block, offset,
+						sizeof(*inodep), &next_block,
+						&next_offset))
+					goto failed_read;
+
+			if((i = squashfs_new_inode(s, inodeb)) == NULL)
+				goto failed_read1;
+
+			i->i_nlink = inodep->nlink;
+			i->i_size = inodep->file_size;
+			i->i_op = &squashfs_dir_inode_ops;
+			i->i_fop = &squashfs_dir_ops;
+			i->i_mode |= S_IFDIR;
+			SQUASHFS_I(i)->start_block = inodep->start_block;
+			SQUASHFS_I(i)->offset = inodep->offset;
+			SQUASHFS_I(i)->u.s2.directory_index_count = 0;
+			SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode;
+
+			TRACE("Directory inode %x:%x, start_block %x, offset "
+					"%x\n", SQUASHFS_INODE_BLK(inode),
+					offset, inodep->start_block,
+					inodep->offset);
+			break;
+		}
+		case SQUASHFS_LDIR_TYPE: {
+			struct squashfs_ldir_inode_header *inodep = &id.ldir;
+			struct squashfs_ldir_inode_header *sinodep = &sid.ldir;
+
+			if (msblk->swap) {
+				if (!squashfs_get_cached_block(s, (char *)
+						sinodep, block, offset,
+						sizeof(*sinodep), &next_block,
+						&next_offset))
+					goto failed_read;
+				SQUASHFS_SWAP_LDIR_INODE_HEADER(inodep,
+						sinodep);
+			} else
+				if (!squashfs_get_cached_block(s, (char *)
+						inodep, block, offset,
+						sizeof(*inodep), &next_block,
+						&next_offset))
+					goto failed_read;
+
+			if((i = squashfs_new_inode(s, inodeb)) == NULL)
+				goto failed_read1;
+
+			i->i_nlink = inodep->nlink;
+			i->i_size = inodep->file_size;
+			i->i_op = &squashfs_dir_inode_ops;
+			i->i_fop = &squashfs_dir_ops;
+			i->i_mode |= S_IFDIR;
+			SQUASHFS_I(i)->start_block = inodep->start_block;
+			SQUASHFS_I(i)->offset = inodep->offset;
+			SQUASHFS_I(i)->u.s2.directory_index_start = next_block;
+			SQUASHFS_I(i)->u.s2.directory_index_offset =
+								next_offset;
+			SQUASHFS_I(i)->u.s2.directory_index_count =
+								inodep->i_count;
+			SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode;
+
+			TRACE("Long directory inode %x:%x, start_block %x, "
+					"offset %x\n",
+					SQUASHFS_INODE_BLK(inode), offset,
+					inodep->start_block, inodep->offset);
+			break;
+		}
+		case SQUASHFS_SYMLINK_TYPE: {
+			struct squashfs_symlink_inode_header *inodep =
+								&id.symlink;
+			struct squashfs_symlink_inode_header *sinodep =
+								&sid.symlink;
+
+			if (msblk->swap) {
+				if (!squashfs_get_cached_block(s, (char *)
+						sinodep, block, offset,
+						sizeof(*sinodep), &next_block,
+						&next_offset))
+					goto failed_read;
+				SQUASHFS_SWAP_SYMLINK_INODE_HEADER(inodep,
+								sinodep);
+			} else
+				if (!squashfs_get_cached_block(s, (char *)
+						inodep, block, offset,
+						sizeof(*inodep), &next_block,
+						&next_offset))
+					goto failed_read;
+
+			if((i = squashfs_new_inode(s, inodeb)) == NULL)
+				goto failed_read1;
+
+			i->i_nlink = inodep->nlink;
+			i->i_size = inodep->symlink_size;
+			i->i_op = &page_symlink_inode_operations;
+			i->i_data.a_ops = &squashfs_symlink_aops;
+			i->i_mode |= S_IFLNK;
+			SQUASHFS_I(i)->start_block = next_block;
+			SQUASHFS_I(i)->offset = next_offset;
+
+			TRACE("Symbolic link inode %x:%x, start_block %llx, "
+					"offset %x\n",
+					SQUASHFS_INODE_BLK(inode), offset,
+					next_block, next_offset);
+			break;
+		 }
+		 case SQUASHFS_BLKDEV_TYPE:
+		 case SQUASHFS_CHRDEV_TYPE: {
+			struct squashfs_dev_inode_header *inodep = &id.dev;
+			struct squashfs_dev_inode_header *sinodep = &sid.dev;
+
+			if (msblk->swap) {
+				if (!squashfs_get_cached_block(s, (char *)
+						sinodep, block, offset,
+						sizeof(*sinodep), &next_block,
+						&next_offset))
+					goto failed_read;
+				SQUASHFS_SWAP_DEV_INODE_HEADER(inodep, sinodep);
+			} else