From 80f784098ff44e086f68f0e8c98b6c6da8702ec4 Mon Sep 17 00:00:00 2001 From: Xiaoming Ni Date: Wed, 19 Oct 2022 11:09:29 +0800 Subject: [PATCH] squashfs: add the mount parameter theads= Patch series 'squashfs: Add the mount parameter "threads="'. Currently, Squashfs supports multiple decompressor parallel modes. However, this mode can be configured only during kernel building and does not support flexible selection during runtime. In the current patch set, the mount parameter "threads=" is added to allow users to select the parallel decompressor mode and configure the number of decompressors when mounting a file system. "threads=" The upper limit is num_online_cpus() * 2. This patch (of 2): Squashfs supports three decompression concurrency modes: Single-thread mode: concurrent reads are blocked and the memory overhead is small. Multi-thread mode/percpu mode: reduces concurrent read blocking but increases memory overhead. The corresponding schema must be fixed at compile time. During mounting, the concurrent decompression mode cannot be adjusted based on file read blocking. The mount parameter theads= is added to select the concurrent decompression mode of a single SquashFS file system image. Link: https://lkml.kernel.org/r/20221019030930.130456-1-nixiaoming@huawei.com Link: https://lkml.kernel.org/r/20221019030930.130456-2-nixiaoming@huawei.com Signed-off-by: Xiaoming Ni Reviewed-by: Phillip Lougher Cc: Jianguo Chen Cc: Jubin Zhong Cc: Zhang Yi Signed-off-by: Andrew Morton --- fs/squashfs/Kconfig | 39 ++++++++++++++++++++--- fs/squashfs/block.c | 2 +- fs/squashfs/decompressor.c | 2 +- fs/squashfs/decompressor_multi.c | 16 +++++++--- fs/squashfs/decompressor_multi_percpu.c | 23 +++++++++----- fs/squashfs/decompressor_single.c | 15 ++++++--- fs/squashfs/squashfs.h | 23 +++++++++++--- fs/squashfs/squashfs_fs_sb.h | 3 +- fs/squashfs/super.c | 56 +++++++++++++++++++++++++++++++-- 9 files changed, 147 insertions(+), 32 deletions(-) diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig index 916e78f..218bacd 100644 --- a/fs/squashfs/Kconfig +++ b/fs/squashfs/Kconfig @@ -54,9 +54,36 @@ config SQUASHFS_FILE_DIRECT endchoice +config SQUASHFS_DECOMP_SINGLE + depends on SQUASHFS + def_bool n + +config SQUASHFS_DECOMP_MULTI + depends on SQUASHFS + def_bool n + +config SQUASHFS_DECOMP_MULTI_PERCPU + depends on SQUASHFS + def_bool n + +config SQUASHFS_CHOICE_DECOMP_BY_MOUNT + bool "Select the parallel decompression mode during mount" + depends on SQUASHFS + default n + select SQUASHFS_DECOMP_SINGLE + select SQUASHFS_DECOMP_MULTI + select SQUASHFS_DECOMP_MULTI_PERCPU + help + Compile all parallel decompression modes and specify the + decompression mode by setting "threads=" during mount. + threads= + + default Decompressor parallelisation is SQUASHFS_DECOMP_SINGLE + choice - prompt "Decompressor parallelisation options" + prompt "Select decompression parallel mode at compile time" depends on SQUASHFS + depends on !SQUASHFS_CHOICE_DECOMP_BY_MOUNT help Squashfs now supports three parallelisation options for decompression. Each one exhibits various trade-offs between @@ -64,15 +91,17 @@ choice If in doubt, select "Single threaded compression" -config SQUASHFS_DECOMP_SINGLE +config SQUASHFS_COMPILE_DECOMP_SINGLE bool "Single threaded compression" + select SQUASHFS_DECOMP_SINGLE help Traditionally Squashfs has used single-threaded decompression. Only one block (data or metadata) can be decompressed at any one time. This limits CPU and memory usage to a minimum. -config SQUASHFS_DECOMP_MULTI +config SQUASHFS_COMPILE_DECOMP_MULTI bool "Use multiple decompressors for parallel I/O" + select SQUASHFS_DECOMP_MULTI help By default Squashfs uses a single decompressor but it gives poor performance on parallel I/O workloads when using multiple CPU @@ -85,8 +114,9 @@ config SQUASHFS_DECOMP_MULTI decompressors per core. It dynamically allocates decompressors on a demand basis. -config SQUASHFS_DECOMP_MULTI_PERCPU +config SQUASHFS_COMPILE_DECOMP_MULTI_PERCPU bool "Use percpu multiple decompressors for parallel I/O" + select SQUASHFS_DECOMP_MULTI_PERCPU help By default Squashfs uses a single decompressor but it gives poor performance on parallel I/O workloads when using multiple CPU @@ -95,7 +125,6 @@ config SQUASHFS_DECOMP_MULTI_PERCPU This decompressor implementation uses a maximum of one decompressor per core. It uses percpu variables to ensure decompression is load-balanced across the cores. - endchoice config SQUASHFS_XATTR diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index 833aca9..bed3bb8 100644 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -216,7 +216,7 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length, res = -EIO; goto out_free_bio; } - res = squashfs_decompress(msblk, bio, offset, length, output); + res = msblk->thread_ops->decompress(msblk, bio, offset, length, output); } else { res = copy_bio_to_actor(bio, output, offset, length); } diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c index d57bef9..8893cb9 100644 --- a/fs/squashfs/decompressor.c +++ b/fs/squashfs/decompressor.c @@ -134,7 +134,7 @@ void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags) if (IS_ERR(comp_opts)) return comp_opts; - stream = squashfs_decompressor_create(msblk, comp_opts); + stream = msblk->thread_ops->create(msblk, comp_opts); if (IS_ERR(stream)) kfree(comp_opts); diff --git a/fs/squashfs/decompressor_multi.c b/fs/squashfs/decompressor_multi.c index db9f12a..eb25432 100644 --- a/fs/squashfs/decompressor_multi.c +++ b/fs/squashfs/decompressor_multi.c @@ -29,12 +29,11 @@ #define MAX_DECOMPRESSOR (num_online_cpus() * 2) -int squashfs_max_decompressors(void) +static int squashfs_max_decompressors(void) { return MAX_DECOMPRESSOR; } - struct squashfs_stream { void *comp_opts; struct list_head strm_list; @@ -59,7 +58,7 @@ static void put_decomp_stream(struct decomp_stream *decomp_strm, wake_up(&stream->wait); } -void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, +static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, void *comp_opts) { struct squashfs_stream *stream; @@ -103,7 +102,7 @@ out: } -void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) +static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) { struct squashfs_stream *stream = msblk->stream; if (stream) { @@ -180,7 +179,7 @@ wait: } -int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, +static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, int offset, int length, struct squashfs_page_actor *output) { @@ -195,3 +194,10 @@ int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, msblk->decompressor->name); return res; } + +const struct squashfs_decompressor_thread_ops squashfs_decompressor_multi = { + .create = squashfs_decompressor_create, + .destroy = squashfs_decompressor_destroy, + .decompress = squashfs_decompress, + .max_decompressors = squashfs_max_decompressors, +}; diff --git a/fs/squashfs/decompressor_multi_percpu.c b/fs/squashfs/decompressor_multi_percpu.c index b881b92..1dfadf7 100644 --- a/fs/squashfs/decompressor_multi_percpu.c +++ b/fs/squashfs/decompressor_multi_percpu.c @@ -25,7 +25,7 @@ struct squashfs_stream { local_lock_t lock; }; -void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, +static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, void *comp_opts) { struct squashfs_stream *stream; @@ -59,7 +59,7 @@ out: return ERR_PTR(err); } -void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) +static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) { struct squashfs_stream __percpu *percpu = (struct squashfs_stream __percpu *) msblk->stream; @@ -75,19 +75,21 @@ void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) } } -int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, +static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, int offset, int length, struct squashfs_page_actor *output) { struct squashfs_stream *stream; + struct squashfs_stream __percpu *percpu = + (struct squashfs_stream __percpu *) msblk->stream; int res; - local_lock(&msblk->stream->lock); - stream = this_cpu_ptr(msblk->stream); + local_lock(&percpu->lock); + stream = this_cpu_ptr(percpu); res = msblk->decompressor->decompress(msblk, stream->stream, bio, offset, length, output); - local_unlock(&msblk->stream->lock); + local_unlock(&percpu->lock); if (res < 0) ERROR("%s decompression failed, data probably corrupt\n", @@ -96,7 +98,14 @@ int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, return res; } -int squashfs_max_decompressors(void) +static int squashfs_max_decompressors(void) { return num_possible_cpus(); } + +const struct squashfs_decompressor_thread_ops squashfs_decompressor_percpu = { + .create = squashfs_decompressor_create, + .destroy = squashfs_decompressor_destroy, + .decompress = squashfs_decompress, + .max_decompressors = squashfs_max_decompressors, +}; diff --git a/fs/squashfs/decompressor_single.c b/fs/squashfs/decompressor_single.c index 4eb3d08..6f16188 100644 --- a/fs/squashfs/decompressor_single.c +++ b/fs/squashfs/decompressor_single.c @@ -24,7 +24,7 @@ struct squashfs_stream { struct mutex mutex; }; -void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, +static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, void *comp_opts) { struct squashfs_stream *stream; @@ -49,7 +49,7 @@ out: return ERR_PTR(err); } -void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) +static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) { struct squashfs_stream *stream = msblk->stream; @@ -59,7 +59,7 @@ void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) } } -int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, +static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, int offset, int length, struct squashfs_page_actor *output) { @@ -78,7 +78,14 @@ int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, return res; } -int squashfs_max_decompressors(void) +static int squashfs_max_decompressors(void) { return 1; } + +const struct squashfs_decompressor_thread_ops squashfs_decompressor_single = { + .create = squashfs_decompressor_create, + .destroy = squashfs_decompressor_destroy, + .decompress = squashfs_decompress, + .max_decompressors = squashfs_max_decompressors, +}; diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h index 9783e01..a6164fd 100644 --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -38,11 +38,24 @@ extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int); extern void *squashfs_decompressor_setup(struct super_block *, unsigned short); /* decompressor_xxx.c */ -extern void *squashfs_decompressor_create(struct squashfs_sb_info *, void *); -extern void squashfs_decompressor_destroy(struct squashfs_sb_info *); -extern int squashfs_decompress(struct squashfs_sb_info *, struct bio *, - int, int, struct squashfs_page_actor *); -extern int squashfs_max_decompressors(void); + +struct squashfs_decompressor_thread_ops { + void * (*create)(struct squashfs_sb_info *msblk, void *comp_opts); + void (*destroy)(struct squashfs_sb_info *msblk); + int (*decompress)(struct squashfs_sb_info *msblk, struct bio *bio, + int offset, int length, struct squashfs_page_actor *output); + int (*max_decompressors)(void); +}; + +#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE +extern const struct squashfs_decompressor_thread_ops squashfs_decompressor_single; +#endif +#ifdef CONFIG_SQUASHFS_DECOMP_MULTI +extern const struct squashfs_decompressor_thread_ops squashfs_decompressor_multi; +#endif +#ifdef CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU +extern const struct squashfs_decompressor_thread_ops squashfs_decompressor_percpu; +#endif /* export.c */ extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64, u64, diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h index 1e90c25..f1e5dad 100644 --- a/fs/squashfs/squashfs_fs_sb.h +++ b/fs/squashfs/squashfs_fs_sb.h @@ -53,7 +53,7 @@ struct squashfs_sb_info { __le64 *xattr_id_table; struct mutex meta_index_mutex; struct meta_index *meta_index; - struct squashfs_stream *stream; + void *stream; __le64 *inode_lookup_table; u64 inode_table; u64 directory_table; @@ -66,5 +66,6 @@ struct squashfs_sb_info { int xattr_ids; unsigned int ids; bool panic_on_errors; + const struct squashfs_decompressor_thread_ops *thread_ops; }; #endif diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 32565da..aac3ea7 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -47,10 +47,12 @@ enum Opt_errors { enum squashfs_param { Opt_errors, + Opt_threads, }; struct squashfs_mount_opts { enum Opt_errors errors; + const struct squashfs_decompressor_thread_ops *thread_ops; }; static const struct constant_table squashfs_param_errors[] = { @@ -61,9 +63,29 @@ static const struct constant_table squashfs_param_errors[] = { static const struct fs_parameter_spec squashfs_fs_parameters[] = { fsparam_enum("errors", Opt_errors, squashfs_param_errors), + fsparam_string("threads", Opt_threads), {} }; +static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts) +{ +#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT + if (strcmp(str, "single") == 0) { + opts->thread_ops = &squashfs_decompressor_single; + return 0; + } + if (strcmp(str, "multi") == 0) { + opts->thread_ops = &squashfs_decompressor_multi; + return 0; + } + if (strcmp(str, "percpu") == 0) { + opts->thread_ops = &squashfs_decompressor_percpu; + return 0; + } +#endif + return -EINVAL; +} + static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct squashfs_mount_opts *opts = fc->fs_private; @@ -78,6 +100,10 @@ static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *para case Opt_errors: opts->errors = result.uint_32; break; + case Opt_threads: + if (squashfs_parse_param_threads(param->string, opts) != 0) + return -EINVAL; + break; default: return -EINVAL; } @@ -167,6 +193,7 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_bdev); goto failed_mount; } + msblk->thread_ops = opts->thread_ops; /* Check the MAJOR & MINOR versions and lookup compression type */ msblk->decompressor = supported_squashfs_filesystem( @@ -252,7 +279,7 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) /* Allocate read_page block */ msblk->read_page = squashfs_cache_init("data", - squashfs_max_decompressors(), msblk->block_size); + msblk->thread_ops->max_decompressors(), msblk->block_size); if (msblk->read_page == NULL) { errorf(fc, "Failed to allocate read_page block"); goto failed_mount; @@ -383,7 +410,7 @@ failed_mount: squashfs_cache_delete(msblk->block_cache); squashfs_cache_delete(msblk->fragment_cache); squashfs_cache_delete(msblk->read_page); - squashfs_decompressor_destroy(msblk); + msblk->thread_ops->destroy(msblk); kfree(msblk->inode_lookup_table); kfree(msblk->fragment_index); kfree(msblk->id_table); @@ -435,6 +462,20 @@ static int squashfs_show_options(struct seq_file *s, struct dentry *root) else seq_puts(s, ",errors=continue"); +#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT + if (msblk->thread_ops == &squashfs_decompressor_single) { + 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 return 0; } @@ -446,6 +487,15 @@ static int squashfs_init_fs_context(struct fs_context *fc) if (!opts) return -ENOMEM; +#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE + opts->thread_ops = &squashfs_decompressor_single; +#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI) + opts->thread_ops = &squashfs_decompressor_multi; +#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU) + opts->thread_ops = &squashfs_decompressor_percpu; +#else +#error "fail: unknown squashfs decompression thread mode?" +#endif fc->fs_private = opts; fc->ops = &squashfs_context_ops; return 0; @@ -478,7 +528,7 @@ static void squashfs_put_super(struct super_block *sb) squashfs_cache_delete(sbi->block_cache); squashfs_cache_delete(sbi->fragment_cache); squashfs_cache_delete(sbi->read_page); - squashfs_decompressor_destroy(sbi); + sbi->thread_ops->destroy(sbi); kfree(sbi->id_table); kfree(sbi->fragment_index); kfree(sbi->meta_index); -- 2.7.4