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Commit b53a0d5f authored by Paul Lawrence's avatar Paul Lawrence Committed by Sahil Sonar
Browse files

ANDROID: Incremental fs: Add zstd compression support 



Bug: 160634783
Test: incfs_test passes
Signed-off-by: default avatarPaul Lawrence <paullawrence@google.com>
Change-Id: If2fea9ca985c2116e16a3680fc97de541af89bb0
parent 5d220345

fs/incfs/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -2,6 +2,8 @@ config INCREMENTAL_FS 
	tristate "Incremental file system support"

	depends on BLOCK

	select DECOMPRESS_LZ4

	select DECOMPRESS_ZSTD

	select CRYPTO_ZSTD

	select CRYPTO_SHA256

	help

	  Incremental FS is a read-only virtual file system that facilitates execution

fs/incfs/data_mgmt.c

+86 −8
Original line number Diff line number Diff line
@@ -28,6 +28,19 @@ static void log_wake_up_all(struct work_struct *work) 
	wake_up_all(&rl->ml_notif_wq);

}



static void zstd_free_workspace(struct work_struct *work)

{

	struct delayed_work *dw = container_of(work, struct delayed_work, work);

	struct mount_info *mi =

		container_of(dw, struct mount_info, mi_zstd_cleanup_work);



	mutex_lock(&mi->mi_zstd_workspace_mutex);

	kvfree(mi->mi_zstd_workspace);

	mi->mi_zstd_workspace = NULL;

	mi->mi_zstd_stream = NULL;

	mutex_unlock(&mi->mi_zstd_workspace_mutex);

}



struct mount_info *incfs_alloc_mount_info(struct super_block *sb,

					  struct mount_options *options,

					  struct path *backing_dir_path)
@@ -53,6 +66,8 @@ struct mount_info *incfs_alloc_mount_info(struct super_block *sb, 
	spin_lock_init(&mi->pending_read_lock);

	INIT_LIST_HEAD(&mi->mi_reads_list_head);

	spin_lock_init(&mi->mi_per_uid_read_timeouts_lock);

	mutex_init(&mi->mi_zstd_workspace_mutex);

	INIT_DELAYED_WORK(&mi->mi_zstd_cleanup_work, zstd_free_workspace);



	error = incfs_realloc_mount_info(mi, options);

	if (error)
@@ -112,11 +127,13 @@ void incfs_free_mount_info(struct mount_info *mi) 
		return;



	flush_delayed_work(&mi->mi_log.ml_wakeup_work);

	flush_delayed_work(&mi->mi_zstd_cleanup_work);



	dput(mi->mi_index_dir);

	dput(mi->mi_incomplete_dir);

	path_put(&mi->mi_backing_dir_path);

	mutex_destroy(&mi->mi_dir_struct_mutex);

	mutex_destroy(&mi->mi_zstd_workspace_mutex);

	put_cred(mi->mi_owner);

	kfree(mi->mi_log.rl_ring_buf);

	kfree(mi->log_xattr);
@@ -357,14 +374,71 @@ void incfs_free_dir_file(struct dir_file *dir) 
	kfree(dir);

}



static ssize_t decompress(struct mem_range src, struct mem_range dst)

static ssize_t zstd_decompress_safe(struct mount_info *mi,

				    struct mem_range src, struct mem_range dst)

{

	int result = LZ4_decompress_safe(src.data, dst.data, src.len, dst.len);

	ssize_t result;

	ZSTD_inBuffer inbuf = {.src = src.data,	.size = src.len};

	ZSTD_outBuffer outbuf = {.dst = dst.data, .size = dst.len};



	result = mutex_lock_interruptible(&mi->mi_zstd_workspace_mutex);

	if (result)

		return result;



	if (!mi->mi_zstd_stream) {

		unsigned int workspace_size = ZSTD_DStreamWorkspaceBound(

						INCFS_DATA_FILE_BLOCK_SIZE);

		void *workspace = kvmalloc(workspace_size, GFP_NOFS);

		ZSTD_DStream *stream;



		if (!workspace) {

			result = -ENOMEM;

			goto out;

		}



		stream = ZSTD_initDStream(INCFS_DATA_FILE_BLOCK_SIZE, workspace,

				  workspace_size);

		if (!stream) {

			kvfree(workspace);

			result = -EIO;

			goto out;

		}



		mi->mi_zstd_workspace = workspace;

		mi->mi_zstd_stream = stream;

	}



	result = ZSTD_decompressStream(mi->mi_zstd_stream, &outbuf, &inbuf) ?

		-EBADMSG : outbuf.pos;



	mod_delayed_work(system_wq, &mi->mi_zstd_cleanup_work,

			 msecs_to_jiffies(5000));



out:

	mutex_unlock(&mi->mi_zstd_workspace_mutex);

	return result;

}



static ssize_t decompress(struct mount_info *mi,

			  struct mem_range src, struct mem_range dst, int alg)

{

	int result;



	switch (alg) {

	case INCFS_BLOCK_COMPRESSED_LZ4:

		result = LZ4_decompress_safe(src.data, dst.data, src.len,

					     dst.len);

		if (result < 0)

			return -EBADMSG;



		return result;



	case INCFS_BLOCK_COMPRESSED_ZSTD:

		return zstd_decompress_safe(mi, src, dst);



	default:

		WARN_ON(true);

		return -EOPNOTSUPP;

	}

}



static void log_read_one_record(struct read_log *rl, struct read_log_state *rs)
@@ -636,9 +710,7 @@ static void convert_data_file_block(struct incfs_blockmap_entry *bme, 
	res_block->db_backing_file_data_offset |=

		le32_to_cpu(bme->me_data_offset_lo);

	res_block->db_stored_size = le16_to_cpu(bme->me_data_size);

	res_block->db_comp_alg = (flags & INCFS_BLOCK_COMPRESSED_LZ4) ?

					 COMPRESSION_LZ4 :

					 COMPRESSION_NONE;

	res_block->db_comp_alg = flags & INCFS_BLOCK_COMPRESSED_MASK;

}



static int get_data_file_block(struct data_file *df, int index,
@@ -1089,7 +1161,8 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, 
		result = incfs_kread(bf, tmp.data, bytes_to_read, pos);

		if (result == bytes_to_read) {

			result =

				decompress(range(tmp.data, bytes_to_read), dst);

				decompress(mi, range(tmp.data, bytes_to_read),

					   dst, block.db_comp_alg);

			if (result < 0) {

				const char *name =

					bf->f_path.dentry->d_name.name;
@@ -1139,8 +1212,13 @@ int incfs_process_new_data_block(struct data_file *df, 
	segment = get_file_segment(df, block->block_index);

	if (!segment)

		return -EFAULT;



	if (block->compression == COMPRESSION_LZ4)

		flags |= INCFS_BLOCK_COMPRESSED_LZ4;

	else if (block->compression == COMPRESSION_ZSTD)

		flags |= INCFS_BLOCK_COMPRESSED_ZSTD;

	else if (block->compression)

		return -EINVAL;



	error = down_read_killable(&segment->rwsem);

	if (error)

fs/incfs/data_mgmt.h

+7 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/rcupdate.h>

#include <linux/completion.h>

#include <linux/wait.h>

#include <linux/zstd.h>

#include <crypto/hash.h>

#include <linux/rwsem.h>
@@ -166,6 +167,12 @@ struct mount_info { 
	spinlock_t mi_per_uid_read_timeouts_lock;

	struct incfs_per_uid_read_timeouts *mi_per_uid_read_timeouts;

	int mi_per_uid_read_timeouts_size;



	/* zstd workspace */

	struct mutex mi_zstd_workspace_mutex;

	void *mi_zstd_workspace;

	ZSTD_DStream *mi_zstd_stream;

	struct delayed_work mi_zstd_cleanup_work;

};



struct data_file_block {

fs/incfs/format.h

+5 −1
Original line number Diff line number Diff line
@@ -195,7 +195,11 @@ struct incfs_file_header { 
} __packed;



enum incfs_block_map_entry_flags {

	INCFS_BLOCK_COMPRESSED_LZ4 = (1 << 0),

	INCFS_BLOCK_COMPRESSED_LZ4 = 1,

	INCFS_BLOCK_COMPRESSED_ZSTD = 2,



	/* Reserve 3 bits for compression alg */

	INCFS_BLOCK_COMPRESSED_MASK = 7,

};



/* Block map entry pointing to an actual location of the data block. */

include/uapi/linux/incrementalfs.h

+2 −1
Original line number Diff line number Diff line
@@ -143,7 +143,8 @@ 


enum incfs_compression_alg {

	COMPRESSION_NONE = 0,

	COMPRESSION_LZ4 = 1

	COMPRESSION_LZ4 = 1,

	COMPRESSION_ZSTD = 2,

};



enum incfs_block_flags {