Commit fb40fe04 authored by Xiaoming Ni's avatar Xiaoming Ni Committed by Andrew Morton
Browse files

squashfs: allows users to configure the number of decompression threads 

The maximum number of threads in the decompressor_multi.c file is fixed
and cannot be adjusted according to user needs.  Therefore, the mount
parameter needs to be added to allow users to configure the number of
threads as required.  The upper limit is num_online_cpus() * 2.

Link: https://lkml.kernel.org/r/20221019030930.130456-3-nixiaoming@huawei.com


Signed-off-by: default avatarXiaoming Ni <nixiaoming@huawei.com>
Reviewed-by: default avatarPhillip Lougher <phillip@squashfs.org.uk>
Cc: Jianguo Chen <chenjianguo3@huawei.com>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 80f78409

fs/squashfs/Kconfig

+14 −2
Original line number Diff line number Diff line
@@ -73,11 +73,10 @@ config SQUASHFS_CHOICE_DECOMP_BY_MOUNT 
	select SQUASHFS_DECOMP_SINGLE

	select SQUASHFS_DECOMP_MULTI

	select SQUASHFS_DECOMP_MULTI_PERCPU

	select SQUASHFS_MOUNT_DECOMP_THREADS

	help

	  Compile all parallel decompression modes and specify the

	  decompression mode by setting "threads=" during mount.

	    threads=<single|multi|percpu>



	  default Decompressor parallelisation is SQUASHFS_DECOMP_SINGLE



choice
@@ -127,6 +126,19 @@ config SQUASHFS_COMPILE_DECOMP_MULTI_PERCPU 
	  decompression is load-balanced across the cores.

endchoice



config SQUASHFS_MOUNT_DECOMP_THREADS

	bool "Add the mount parameter 'threads=' for squashfs"

	depends on SQUASHFS

	depends on SQUASHFS_DECOMP_MULTI

	default n

	help

	  Use threads= to set the decompression parallel mode and the number of threads.

	  If SQUASHFS_CHOICE_DECOMP_BY_MOUNT=y

	      threads=<single|multi|percpu|1|2|3|...>

	  else

	      threads=<2|3|...>

	  The upper limit is num_online_cpus() * 2.



config SQUASHFS_XATTR

	bool "Squashfs XATTR support"

	depends on SQUASHFS

fs/squashfs/decompressor_multi.c

+2 −2
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk, 
		 * If there is no available decomp and already full,

		 * let's wait for releasing decomp from other users.

		 */

		if (stream->avail_decomp >= MAX_DECOMPRESSOR)

		if (stream->avail_decomp >= msblk->max_thread_num)

			goto wait;



		/* Let's allocate new decomp */
@@ -160,7 +160,7 @@ static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk, 
		}



		stream->avail_decomp++;

		WARN_ON(stream->avail_decomp > MAX_DECOMPRESSOR);

		WARN_ON(stream->avail_decomp > msblk->max_thread_num);



		mutex_unlock(&stream->mutex);

		break;

fs/squashfs/squashfs_fs_sb.h

+1 −0
Original line number Diff line number Diff line
@@ -67,5 +67,6 @@ struct squashfs_sb_info { 
	unsigned int				ids;

	bool					panic_on_errors;

	const struct squashfs_decompressor_thread_ops *thread_ops;

	int					max_thread_num;

};

#endif

fs/squashfs/super.c

+49 −6
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ enum squashfs_param { 
struct squashfs_mount_opts {

	enum Opt_errors errors;

	const struct squashfs_decompressor_thread_ops *thread_ops;

	int thread_num;

};



static const struct constant_table squashfs_param_errors[] = {
@@ -67,7 +68,8 @@ static const struct fs_parameter_spec squashfs_fs_parameters[] = { 
	{}

};



static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts)



static int squashfs_parse_param_threads_str(const char *str, struct squashfs_mount_opts *opts)

{

#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT

	if (strcmp(str, "single") == 0) {
@@ -86,6 +88,42 @@ static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_o 
	return -EINVAL;

}



static int squashfs_parse_param_threads_num(const char *str, struct squashfs_mount_opts *opts)

{

#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS

	int ret;

	unsigned long num;



	ret = kstrtoul(str, 0, &num);

	if (ret != 0)

		return -EINVAL;

	if (num > 1) {

		opts->thread_ops = &squashfs_decompressor_multi;

		if (num > opts->thread_ops->max_decompressors())

			return -EINVAL;

		opts->thread_num = (int)num;

		return 0;

	}

#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE

	if (num == 1) {

		opts->thread_ops = &squashfs_decompressor_single;

		opts->thread_num = 1;

		return 0;

	}

#endif

#endif /* !CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS */

	return -EINVAL;

}



static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts)

{

	int ret = squashfs_parse_param_threads_str(str, opts);



	if (ret == 0)

		return ret;

	return squashfs_parse_param_threads_num(str, opts);

}



static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *param)

{

	struct squashfs_mount_opts *opts = fc->fs_private;
@@ -194,6 +232,11 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) 
		goto failed_mount;

	}

	msblk->thread_ops = opts->thread_ops;

	if (opts->thread_num == 0) {

		msblk->max_thread_num = msblk->thread_ops->max_decompressors();

	} else {

		msblk->max_thread_num = opts->thread_num;

	}



	/* Check the MAJOR & MINOR versions and lookup compression type */

	msblk->decompressor = supported_squashfs_filesystem(
@@ -279,7 +322,7 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) 


	/* Allocate read_page block */

	msblk->read_page = squashfs_cache_init("data",

		msblk->thread_ops->max_decompressors(), msblk->block_size);

		msblk->max_thread_num, msblk->block_size);

	if (msblk->read_page == NULL) {

		errorf(fc, "Failed to allocate read_page block");

		goto failed_mount;
@@ -467,14 +510,13 @@ static int squashfs_show_options(struct seq_file *s, struct dentry *root) 
		seq_puts(s, ",threads=single");

		return 0;

	}

	if (msblk->thread_ops == &squashfs_decompressor_multi) {

		seq_puts(s, ",threads=multi");

		return 0;

	}

	if (msblk->thread_ops == &squashfs_decompressor_percpu) {

		seq_puts(s, ",threads=percpu");

		return 0;

	}

#endif

#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS

	seq_printf(s, ",threads=%d", msblk->max_thread_num);

#endif

	return 0;

}
@@ -496,6 +538,7 @@ static int squashfs_init_fs_context(struct fs_context *fc) 
#else

#error "fail: unknown squashfs decompression thread mode?"

#endif

	opts->thread_num = 0;

	fc->fs_private = opts;

	fc->ops = &squashfs_context_ops;

	return 0;