From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5753D2E5D32 for ; Tue, 16 Dec 2025 02:20:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765851609; cv=none; b=qU0/Vude91ikTB3er9ltEAuIwQkgPUAQ4LZgnHHOhCvv0JpQBpIraafPqgYTiJnLYGHmYufWM3ox56ZYN9q2VzNCFLxxXb1fvkzKBMKVZzgkijubLQSNgtFtivdr6aVECICn2Sws35OVdlmgHTcFG5Etom6pPMbnqURZEXhaPU4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765851609; c=relaxed/simple; bh=RC3/T5nIJYzmK+sJREDoRrYwSyFt3NhzhmOwtxTfM3o=; h=Date:To:From:Subject:Message-Id; b=Cb1j08kHpLCPWGKMmbYz0thOPBlzbgx31nYYdoaawOfZT9+PyUDsPKEpE/Hg0JeasS+GrFDOuxNKwQ+POlCjTEn9ESq1RXwfzvBjY8VV2RoIK5+Blv+JFr6ZXqTx/WIaMWJ+ywXyLJqB1/I8z02kJeupmDmMSl0NAmCWsA/E3dI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=JtmTcHZB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="JtmTcHZB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BCADCC4CEFB; Tue, 16 Dec 2025 02:20:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1765851606; bh=RC3/T5nIJYzmK+sJREDoRrYwSyFt3NhzhmOwtxTfM3o=; h=Date:To:From:Subject:From; b=JtmTcHZBn4FaICZb4xbohVCiiEh//2+ufuZ3S4ZaIDKrayI1pKg4iyCfAUxqX35MN zvzKFrcT6867zvNBkBrvhrheQqDXpz8uALTScP4lncSCIaUI+ie0f4mTPFLF212VF7 kO8/yM2kPOQ+kD4cu3SrGCCUMoaflV8VJ1V9eYns= Date: Mon, 15 Dec 2025 18:20:06 -0800 To: mm-commits@vger.kernel.org,stevensd@google.com,richardycc@google.com,minchan@google.com,bgeffon@google.com,senozhatsky@chromium.org,akpm@linux-foundation.org From: Andrew Morton Subject: + zram-switch-to-guard-for-init_lock.patch added to mm-new branch Message-Id: <20251216022006.BCADCC4CEFB@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: zram: switch to guard() for init_lock has been added to the -mm mm-new branch. Its filename is zram-switch-to-guard-for-init_lock.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-switch-to-guard-for-init_lock.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Sergey Senozhatsky Subject: zram: switch to guard() for init_lock Date: Mon, 1 Dec 2025 18:47:53 +0900 Use init_lock guard() in sysfs store/show handlers, in order to simplify and, more importantly, to modernize the code. While at it, fix up more coding styles. Link: https://lkml.kernel.org/r/20251201094754.4149975-7-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Cc: Brian Geffon Cc: David Stevens Cc: Minchan Kim Cc: Richard Chang Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 211 +++++++++++--------------------- 1 file changed, 77 insertions(+), 134 deletions(-) --- a/drivers/block/zram/zram_drv.c~zram-switch-to-guard-for-init_lock +++ a/drivers/block/zram/zram_drv.c @@ -360,15 +360,14 @@ static bool page_same_filled(void *ptr, return true; } -static ssize_t initstate_show(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t initstate_show(struct device *dev, struct device_attribute *attr, + char *buf) { u32 val; struct zram *zram = dev_to_zram(dev); - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); val = init_done(zram); - up_read(&zram->init_lock); return sysfs_emit(buf, "%u\n", val); } @@ -382,7 +381,8 @@ static ssize_t disksize_show(struct devi } static ssize_t mem_limit_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) + struct device_attribute *attr, const char *buf, + size_t len) { u64 limit; char *tmp; @@ -392,15 +392,15 @@ static ssize_t mem_limit_store(struct de if (buf == tmp) /* no chars parsed, invalid input */ return -EINVAL; - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); zram->limit_pages = PAGE_ALIGN(limit) >> PAGE_SHIFT; - up_write(&zram->init_lock); return len; } static ssize_t mem_used_max_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) + struct device_attribute *attr, + const char *buf, size_t len) { int err; unsigned long val; @@ -410,12 +410,11 @@ static ssize_t mem_used_max_store(struct if (err || val != 0) return -EINVAL; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); if (init_done(zram)) { atomic_long_set(&zram->stats.max_used_pages, zs_get_total_pages(zram->mem_pool)); } - up_read(&zram->init_lock); return len; } @@ -458,12 +457,11 @@ static void mark_idle(struct zram *zram, } } -static ssize_t idle_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) +static ssize_t idle_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) { struct zram *zram = dev_to_zram(dev); ktime_t cutoff_time = 0; - ssize_t rv = -EINVAL; if (!sysfs_streq(buf, "all")) { /* @@ -476,24 +474,19 @@ static ssize_t idle_store(struct device cutoff_time = ktime_sub(ktime_get_boottime(), ns_to_ktime(age_sec * NSEC_PER_SEC)); else - goto out; + return -EINVAL; } - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); if (!init_done(zram)) - goto out_unlock; + return -EINVAL; /* * A cutoff_time of 0 marks everything as idle, this is the * "all" behavior. */ mark_idle(zram, cutoff_time); - rv = len; - -out_unlock: - up_read(&zram->init_lock); -out: - return rv; + return len; } #ifdef CONFIG_ZRAM_WRITEBACK @@ -546,13 +539,12 @@ static ssize_t bd_stat_show(struct devic struct zram *zram = dev_to_zram(dev); ssize_t ret; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); ret = sysfs_emit(buf, "%8llu %8llu %8llu\n", FOUR_K((u64)atomic64_read(&zram->stats.bd_count)), FOUR_K((u64)atomic64_read(&zram->stats.bd_reads)), FOUR_K((u64)atomic64_read(&zram->stats.bd_writes))); - up_read(&zram->init_lock); return ret; } @@ -567,14 +559,12 @@ static ssize_t writeback_compressed_stor if (kstrtobool(buf, &val)) return -EINVAL; - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); if (init_done(zram)) { - up_write(&zram->init_lock); return -EBUSY; } zram->wb_compressed = val; - up_write(&zram->init_lock); return len; } @@ -586,9 +576,8 @@ static ssize_t writeback_compressed_show bool val; struct zram *zram = dev_to_zram(dev); - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); val = zram->wb_compressed; - up_read(&zram->init_lock); return sysfs_emit(buf, "%d\n", val); } @@ -599,17 +588,14 @@ static ssize_t writeback_limit_enable_st { struct zram *zram = dev_to_zram(dev); u64 val; - ssize_t ret = -EINVAL; if (kstrtoull(buf, 10, &val)) - return ret; + return -EINVAL; - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); zram->wb_limit_enable = val; - up_write(&zram->init_lock); - ret = len; - return ret; + return len; } static ssize_t writeback_limit_enable_show(struct device *dev, @@ -619,9 +605,8 @@ static ssize_t writeback_limit_enable_sh bool val; struct zram *zram = dev_to_zram(dev); - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); val = zram->wb_limit_enable; - up_read(&zram->init_lock); return sysfs_emit(buf, "%d\n", val); } @@ -632,10 +617,9 @@ static ssize_t writeback_limit_store(str { struct zram *zram = dev_to_zram(dev); u64 val; - ssize_t ret = -EINVAL; if (kstrtoull(buf, 10, &val)) - return ret; + return -EINVAL; /* * When the page size is greater than 4KB, if bd_wb_limit is set to @@ -647,12 +631,10 @@ static ssize_t writeback_limit_store(str */ val = rounddown(val, PAGE_SIZE / 4096); - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); zram->bd_wb_limit = val; - up_write(&zram->init_lock); - ret = len; - return ret; + return len; } static ssize_t writeback_limit_show(struct device *dev, @@ -661,9 +643,8 @@ static ssize_t writeback_limit_show(stru u64 val; struct zram *zram = dev_to_zram(dev); - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); val = zram->bd_wb_limit; - up_read(&zram->init_lock); return sysfs_emit(buf, "%llu\n", val); } @@ -681,9 +662,8 @@ static ssize_t writeback_batch_size_stor if (!val) return -EINVAL; - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); zram->wb_batch_size = val; - up_write(&zram->init_lock); return len; } @@ -695,9 +675,8 @@ static ssize_t writeback_batch_size_show u32 val; struct zram *zram = dev_to_zram(dev); - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); val = zram->wb_batch_size; - up_read(&zram->init_lock); return sysfs_emit(buf, "%u\n", val); } @@ -717,37 +696,33 @@ static void reset_bdev(struct zram *zram } static ssize_t backing_dev_show(struct device *dev, - struct device_attribute *attr, char *buf) + struct device_attribute *attr, char *buf) { struct file *file; struct zram *zram = dev_to_zram(dev); char *p; ssize_t ret; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); file = zram->backing_dev; if (!file) { memcpy(buf, "none\n", 5); - up_read(&zram->init_lock); return 5; } p = file_path(file, buf, PAGE_SIZE - 1); - if (IS_ERR(p)) { - ret = PTR_ERR(p); - goto out; - } + if (IS_ERR(p)) + return PTR_ERR(p); ret = strlen(p); memmove(buf, p, ret); buf[ret++] = '\n'; -out: - up_read(&zram->init_lock); return ret; } static ssize_t backing_dev_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) + struct device_attribute *attr, const char *buf, + size_t len) { char *file_name; size_t sz; @@ -762,7 +737,7 @@ static ssize_t backing_dev_store(struct if (!file_name) return -ENOMEM; - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); if (init_done(zram)) { pr_info("Can't setup backing device for initialized device\n"); err = -EBUSY; @@ -810,7 +785,6 @@ static ssize_t backing_dev_store(struct zram->backing_dev = backing_dev; zram->bitmap = bitmap; zram->nr_pages = nr_pages; - up_write(&zram->init_lock); pr_info("setup backing device %s\n", file_name); kfree(file_name); @@ -822,8 +796,6 @@ out: if (backing_dev) filp_close(backing_dev, NULL); - up_write(&zram->init_lock); - kfree(file_name); return err; @@ -1291,33 +1263,29 @@ static ssize_t writeback_store(struct de ssize_t ret = len; int err, mode = 0; - down_read(&zram->init_lock); - if (!init_done(zram)) { - up_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); + if (!init_done(zram)) return -EINVAL; - } /* Do not permit concurrent post-processing actions. */ - if (atomic_xchg(&zram->pp_in_progress, 1)) { - up_read(&zram->init_lock); + if (atomic_xchg(&zram->pp_in_progress, 1)) return -EAGAIN; - } if (!zram->backing_dev) { ret = -ENODEV; - goto release_init_lock; + goto out; } pp_ctl = init_pp_ctl(); if (!pp_ctl) { ret = -ENOMEM; - goto release_init_lock; + goto out; } wb_ctl = init_wb_ctl(zram); if (!wb_ctl) { ret = -ENOMEM; - goto release_init_lock; + goto out; } args = skip_spaces(buf); @@ -1341,7 +1309,7 @@ static ssize_t writeback_store(struct de err = parse_mode(param, &mode); if (err) { ret = err; - goto release_init_lock; + goto out; } scan_slots_for_writeback(zram, mode, lo, hi, pp_ctl); @@ -1352,7 +1320,7 @@ static ssize_t writeback_store(struct de err = parse_mode(val, &mode); if (err) { ret = err; - goto release_init_lock; + goto out; } scan_slots_for_writeback(zram, mode, lo, hi, pp_ctl); @@ -1363,7 +1331,7 @@ static ssize_t writeback_store(struct de err = parse_page_index(val, nr_pages, &lo, &hi); if (err) { ret = err; - goto release_init_lock; + goto out; } scan_slots_for_writeback(zram, mode, lo, hi, pp_ctl); @@ -1374,7 +1342,7 @@ static ssize_t writeback_store(struct de err = parse_page_indexes(val, nr_pages, &lo, &hi); if (err) { ret = err; - goto release_init_lock; + goto out; } scan_slots_for_writeback(zram, mode, lo, hi, pp_ctl); @@ -1386,11 +1354,10 @@ static ssize_t writeback_store(struct de if (err) ret = err; -release_init_lock: +out: release_pp_ctl(zram, pp_ctl); release_wb_ctl(wb_ctl); atomic_set(&zram->pp_in_progress, 0); - up_read(&zram->init_lock); return ret; } @@ -1608,9 +1575,8 @@ static ssize_t read_block_state(struct f if (!kbuf) return -ENOMEM; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); if (!init_done(zram)) { - up_read(&zram->init_lock); kvfree(kbuf); return -EINVAL; } @@ -1646,7 +1612,6 @@ next: *ppos += 1; } - up_read(&zram->init_lock); if (copy_to_user(buf, kbuf, written)) written = -EFAULT; kvfree(kbuf); @@ -1713,16 +1678,14 @@ static int __comp_algorithm_store(struct return -EINVAL; } - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); if (init_done(zram)) { - up_write(&zram->init_lock); kfree(compressor); pr_info("Can't change algorithm for initialized device\n"); return -EBUSY; } comp_algorithm_set(zram, prio, compressor); - up_write(&zram->init_lock); return 0; } @@ -1843,9 +1806,8 @@ static ssize_t comp_algorithm_show(struc struct zram *zram = dev_to_zram(dev); ssize_t sz; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); sz = zcomp_available_show(zram->comp_algs[ZRAM_PRIMARY_COMP], buf, 0); - up_read(&zram->init_lock); return sz; } @@ -1870,7 +1832,7 @@ static ssize_t recomp_algorithm_show(str ssize_t sz = 0; u32 prio; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) { if (!zram->comp_algs[prio]) continue; @@ -1878,7 +1840,6 @@ static ssize_t recomp_algorithm_show(str sz += sysfs_emit_at(buf, sz, "#%d: ", prio); sz += zcomp_available_show(zram->comp_algs[prio], buf, sz); } - up_read(&zram->init_lock); return sz; } @@ -1924,42 +1885,38 @@ static ssize_t recomp_algorithm_store(st } #endif -static ssize_t compact_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) +static ssize_t compact_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) { struct zram *zram = dev_to_zram(dev); - down_read(&zram->init_lock); - if (!init_done(zram)) { - up_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); + if (!init_done(zram)) return -EINVAL; - } zs_compact(zram->mem_pool); - up_read(&zram->init_lock); return len; } -static ssize_t io_stat_show(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t io_stat_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct zram *zram = dev_to_zram(dev); ssize_t ret; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); ret = sysfs_emit(buf, "%8llu %8llu 0 %8llu\n", (u64)atomic64_read(&zram->stats.failed_reads), (u64)atomic64_read(&zram->stats.failed_writes), (u64)atomic64_read(&zram->stats.notify_free)); - up_read(&zram->init_lock); return ret; } -static ssize_t mm_stat_show(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t mm_stat_show(struct device *dev, struct device_attribute *attr, + char *buf) { struct zram *zram = dev_to_zram(dev); struct zs_pool_stats pool_stats; @@ -1969,7 +1926,7 @@ static ssize_t mm_stat_show(struct devic memset(&pool_stats, 0x00, sizeof(struct zs_pool_stats)); - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); if (init_done(zram)) { mem_used = zs_get_total_pages(zram->mem_pool); zs_pool_stats(zram->mem_pool, &pool_stats); @@ -1989,7 +1946,6 @@ static ssize_t mm_stat_show(struct devic atomic_long_read(&pool_stats.pages_compacted), (u64)atomic64_read(&zram->stats.huge_pages), (u64)atomic64_read(&zram->stats.huge_pages_since)); - up_read(&zram->init_lock); return ret; } @@ -2001,12 +1957,11 @@ static ssize_t debug_stat_show(struct de struct zram *zram = dev_to_zram(dev); ssize_t ret; - down_read(&zram->init_lock); + guard(rwsem_read)(&zram->init_lock); ret = sysfs_emit(buf, "version: %d\n0 %8llu\n", version, (u64)atomic64_read(&zram->stats.miss_free)); - up_read(&zram->init_lock); return ret; } @@ -2669,17 +2624,13 @@ static ssize_t recompress_store(struct d if (threshold >= huge_class_size) return -EINVAL; - down_read(&zram->init_lock); - if (!init_done(zram)) { - ret = -EINVAL; - goto release_init_lock; - } + guard(rwsem_read)(&zram->init_lock); + if (!init_done(zram)) + return -EINVAL; /* Do not permit concurrent post-processing actions. */ - if (atomic_xchg(&zram->pp_in_progress, 1)) { - up_read(&zram->init_lock); + if (atomic_xchg(&zram->pp_in_progress, 1)) return -EAGAIN; - } if (algo) { bool found = false; @@ -2697,26 +2648,26 @@ static ssize_t recompress_store(struct d if (!found) { ret = -EINVAL; - goto release_init_lock; + goto out; } } prio_max = min(prio_max, (u32)zram->num_active_comps); if (prio >= prio_max) { ret = -EINVAL; - goto release_init_lock; + goto out; } page = alloc_page(GFP_KERNEL); if (!page) { ret = -ENOMEM; - goto release_init_lock; + goto out; } ctl = init_pp_ctl(); if (!ctl) { ret = -ENOMEM; - goto release_init_lock; + goto out; } scan_slots_for_recompress(zram, mode, prio_max, ctl); @@ -2747,12 +2698,11 @@ next: cond_resched(); } -release_init_lock: +out: if (page) __free_page(page); release_pp_ctl(zram, ctl); atomic_set(&zram->pp_in_progress, 0); - up_read(&zram->init_lock); return ret; } #endif @@ -2931,7 +2881,7 @@ static void zram_destroy_comps(struct zr static void zram_reset_device(struct zram *zram) { - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); zram->limit_pages = 0; @@ -2947,11 +2897,10 @@ static void zram_reset_device(struct zra reset_bdev(zram); comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor); - up_write(&zram->init_lock); } -static ssize_t disksize_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) +static ssize_t disksize_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) { u64 disksize; struct zcomp *comp; @@ -2963,18 +2912,15 @@ static ssize_t disksize_store(struct dev if (!disksize) return -EINVAL; - down_write(&zram->init_lock); + guard(rwsem_write)(&zram->init_lock); if (init_done(zram)) { pr_info("Cannot change disksize for initialized device\n"); - err = -EBUSY; - goto out_unlock; + return -EBUSY; } disksize = PAGE_ALIGN(disksize); - if (!zram_meta_alloc(zram, disksize)) { - err = -ENOMEM; - goto out_unlock; - } + if (!zram_meta_alloc(zram, disksize)) + return -ENOMEM; for (prio = ZRAM_PRIMARY_COMP; prio < ZRAM_MAX_COMPS; prio++) { if (!zram->comp_algs[prio]) @@ -2994,15 +2940,12 @@ static ssize_t disksize_store(struct dev } zram->disksize = disksize; set_capacity_and_notify(zram->disk, zram->disksize >> SECTOR_SHIFT); - up_write(&zram->init_lock); return len; out_free_comps: zram_destroy_comps(zram); zram_meta_free(zram, disksize); -out_unlock: - up_write(&zram->init_lock); return err; } _ Patches currently in -mm which might be from senozhatsky@chromium.org are zram-document-writeback_batch_size.patch zram-move-bd_stat-to-writeback-section.patch zram-rename-zram_free_page.patch zram-switch-to-guard-for-init_lock.patch zram-consolidate-device-attr-declarations.patch