From: Sergey Senozhatsky senozhatsky@chromium.org
mainline inclusion from mainline-v6.2-rc1 commit 001d9273570115b2eb360d5452bbc46f6cc063a1 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7TWVA CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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Introduce recomp_algorithm sysfs knob that controls secondary algorithm selection used for recompression.
We will support up to 3 secondary compression algorithms which are sorted in order of their priority. To select an algorithm user has to provide its name and priority:
echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm echo "algo=deflate priority=2" > /sys/block/zramX/recomp_algorithm
During recompression zram iterates through the list of registered secondary algorithms in order of their priorities.
We also have a short version for cases when there is only one secondary compression algorithm:
echo "algo=zstd" > /sys/block/zramX/recomp_algorithm
This will register zstd as the secondary algorithm with priority 1.
Link: https://lkml.kernel.org/r/20221109115047.2921851-3-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky senozhatsky@chromium.org Acked-by: Minchan Kim minchan@kernel.org Cc: Alexey Romanov avromanov@sberdevices.ru Cc: Nhat Pham nphamcs@gmail.com Cc: Nitin Gupta ngupta@vflare.org Cc: Suleiman Souhlal suleiman@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org
Conflicts: drivers/block/zram/zram_drv.c
Signed-off-by: Jinjiang Tu tujinjiang@huawei.com --- drivers/block/zram/zram_drv.c | 124 ++++++++++++++++++++++++++++------ 1 file changed, 105 insertions(+), 19 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index cb704ce6c24d..369b24f871ce 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -979,31 +979,28 @@ static ssize_t max_comp_streams_store(struct device *dev, return len; }
-static ssize_t comp_algorithm_show(struct device *dev, - struct device_attribute *attr, char *buf) +static void comp_algorithm_set(struct zram *zram, u32 prio, const char *alg) { - size_t sz; - struct zram *zram = dev_to_zram(dev); + /* Do not free statically defined compression algorithms */ + if (zram->comp_algs[prio] != default_compressor) + kfree(zram->comp_algs[prio]); + + zram->comp_algs[prio] = alg; +} + +static ssize_t __comp_algorithm_show(struct zram *zram, u32 prio, char *buf) +{ + ssize_t sz;
down_read(&zram->init_lock); - sz = zcomp_available_show(zram->comp_algs[ZRAM_PRIMARY_COMP], buf); + sz = zcomp_available_show(zram->comp_algs[prio], buf); up_read(&zram->init_lock);
return sz; }
-static void comp_algorithm_set(struct zram *zram, u32 prio, const char *alg) -{ - /* Do not kfree() algs that we didn't allocate, IOW the default ones */ - if (zram->comp_algs[prio] != default_compressor) - kfree(zram->comp_algs[prio]); - zram->comp_algs[prio] = alg; -} - -static ssize_t comp_algorithm_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) +static int __comp_algorithm_store(struct zram *zram, u32 prio, const char *buf) { - struct zram *zram = dev_to_zram(dev); char *compressor; size_t sz;
@@ -1032,10 +1029,93 @@ static ssize_t comp_algorithm_store(struct device *dev, return -EBUSY; }
- comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, compressor); + comp_algorithm_set(zram, prio, compressor); up_write(&zram->init_lock); - return len; + return 0; +} + +static ssize_t comp_algorithm_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return __comp_algorithm_show(zram, ZRAM_PRIMARY_COMP, buf); +} + +static ssize_t comp_algorithm_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct zram *zram = dev_to_zram(dev); + int ret; + + ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, buf); + return ret ? ret : len; +} + +#ifdef CONFIG_ZRAM_MULTI_COMP +static ssize_t recomp_algorithm_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct zram *zram = dev_to_zram(dev); + ssize_t sz = 0; + u32 prio; + + for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) { + if (!zram->comp_algs[prio]) + continue; + + sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2, "#%d: ", prio); + sz += __comp_algorithm_show(zram, prio, buf + sz); + } + + return sz; +} + +static ssize_t recomp_algorithm_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct zram *zram = dev_to_zram(dev); + int prio = ZRAM_SECONDARY_COMP; + char *args, *param, *val; + char *alg = NULL; + int ret; + + args = skip_spaces(buf); + while (*args) { + args = next_arg(args, ¶m, &val); + + if (!*val) + return -EINVAL; + + if (!strcmp(param, "algo")) { + alg = val; + continue; + } + + if (!strcmp(param, "priority")) { + ret = kstrtoint(val, 10, &prio); + if (ret) + return ret; + continue; + } + } + + if (!alg) + return -EINVAL; + + if (prio < ZRAM_SECONDARY_COMP || prio >= ZRAM_MAX_COMPS) + return -EINVAL; + + ret = __comp_algorithm_store(zram, prio, alg); + return ret ? ret : len; } +#endif
static ssize_t compact_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) @@ -1888,6 +1968,9 @@ static DEVICE_ATTR_WO(writeback); static DEVICE_ATTR_RW(writeback_limit); static DEVICE_ATTR_RW(writeback_limit_enable); #endif +#ifdef CONFIG_ZRAM_MULTI_COMP +static DEVICE_ATTR_RW(recomp_algorithm); +#endif
static struct attribute *zram_disk_attrs[] = { &dev_attr_disksize.attr, @@ -1911,6 +1994,9 @@ static struct attribute *zram_disk_attrs[] = { &dev_attr_bd_stat.attr, #endif &dev_attr_debug_stat.attr, +#ifdef CONFIG_ZRAM_MULTI_COMP + &dev_attr_recomp_algorithm.attr, +#endif NULL, };
@@ -2003,7 +2089,7 @@ static int zram_add(void) blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, zram->disk->queue); device_add_disk(NULL, zram->disk, zram_disk_attr_groups);
- zram->comp_algs[ZRAM_PRIMARY_COMP] = default_compressor; + comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor);
zram_debugfs_register(zram); pr_info("Added device: %s\n", zram->disk->disk_name);