zram: rename writeback_compressed device attr

Rename writeback_compressed attr to compressed_writeback to avoid possible
confusion and have more natural naming.  writeback_compressed may look
like an alternative version of writeback while in fact
writeback_compressed only sets a writeback property.  Make this
distinction more clear with a new compressed_writeback name.

This updates a feature which is new in 7.0-rcX.

Link: https://lkml.kernel.org/r/20260226025429.1042083-1-senozhatsky@chromium.org
Fixes: 4c1d61389e8e ("zram: introduce writeback_compressed device attribute")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Suggested-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Christoph Böhmwalder" <christoph.boehmwalder@linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram
index e538d4850d6112437861bcc09e0669766c383978..64c03010e95113d78e0fd378babfab377c716644 100644 (file)
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -151,11 +151,11 @@ Description:
                The algorithm_params file is write-only and is used to setup
                compression algorithm parameters.
 
-What:          /sys/block/zram<id>/writeback_compressed
+What:          /sys/block/zram<id>/compressed_writeback
 Date:          Decemeber 2025
 Contact:       Richard Chang <richardycc@google.com>
 Description:
-               The writeback_compressed device atrribute toggles compressed
+               The compressed_writeback device atrribute toggles compressed
                writeback feature.
 
 What:          /sys/block/zram<id>/writeback_batch_size

diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst
index 94bb7f2245eef26c49116ae730afe9ef6e881998..451fa00d3004b5ed1b37e042200938661d381e95 100644 (file)
--- a/Documentation/admin-guide/blockdev/zram.rst
+++ b/Documentation/admin-guide/blockdev/zram.rst
@@ -216,7 +216,7 @@ writeback_limit     WO      specifies the maximum amount of write IO zram
 writeback_limit_enable  RW     show and set writeback_limit feature
 writeback_batch_size   RW      show and set maximum number of in-flight
                                writeback operations
-writeback_compressed   RW      show and set compressed writeback feature
+compressed_writeback   RW      show and set compressed writeback feature
 comp_algorithm         RW      show and change the compression algorithm
 algorithm_params       WO      setup compression algorithm parameters
 compact                WO      trigger memory compaction
@@ -439,11 +439,11 @@ budget in next setting is user's job.
 By default zram stores written back pages in decompressed (raw) form, which
 means that writeback operation involves decompression of the page before
 writing it to the backing device.  This behavior can be changed by enabling
-`writeback_compressed` feature, which causes zram to write compressed pages
+`compressed_writeback` feature, which causes zram to write compressed pages
 to the backing device, thus avoiding decompression overhead.  To enable
 this feature, execute::
 
-       $ echo yes > /sys/block/zramX/writeback_compressed
+       $ echo yes > /sys/block/zramX/compressed_writeback
 
 Note that this feature should be configured before the `zramX` device is
 initialized.

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index bca33403fc8bf872569c63e65af0fe143287eaaf..a324ede6206d3a99eb102f87b929700a41ee5b3b 100644 (file)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -549,7 +549,7 @@ static ssize_t bd_stat_show(struct device *dev, struct device_attribute *attr,
        return ret;
 }
 
-static ssize_t writeback_compressed_store(struct device *dev,
+static ssize_t compressed_writeback_store(struct device *dev,
                                          struct device_attribute *attr,
                                          const char *buf, size_t len)
 {
@@ -564,12 +564,12 @@ static ssize_t writeback_compressed_store(struct device *dev,
                return -EBUSY;
        }
 
-       zram->wb_compressed = val;
+       zram->compressed_wb = val;
 
        return len;
 }
 
-static ssize_t writeback_compressed_show(struct device *dev,
+static ssize_t compressed_writeback_show(struct device *dev,
                                         struct device_attribute *attr,
                                         char *buf)
 {
@@ -577,7 +577,7 @@ static ssize_t writeback_compressed_show(struct device *dev,
        struct zram *zram = dev_to_zram(dev);
 
        guard(rwsem_read)(&zram->dev_lock);
-       val = zram->wb_compressed;
+       val = zram->compressed_wb;
 
        return sysfs_emit(buf, "%d\n", val);
 }
@@ -946,7 +946,7 @@ static int zram_writeback_complete(struct zram *zram, struct zram_wb_req *req)
                goto out;
        }
 
-       if (zram->wb_compressed) {
+       if (zram->compressed_wb) {
                /*
                 * ZRAM_WB slots get freed, we need to preserve data required
                 * for read decompression.
@@ -960,7 +960,7 @@ static int zram_writeback_complete(struct zram *zram, struct zram_wb_req *req)
        set_slot_flag(zram, index, ZRAM_WB);
        set_slot_handle(zram, index, req->blk_idx);
 
-       if (zram->wb_compressed) {
+       if (zram->compressed_wb) {
                if (huge)
                        set_slot_flag(zram, index, ZRAM_HUGE);
                set_slot_size(zram, index, size);
@@ -1100,7 +1100,7 @@ static int zram_writeback_slots(struct zram *zram,
                 */
                if (!test_slot_flag(zram, index, ZRAM_PP_SLOT))
                        goto next;
-               if (zram->wb_compressed)
+               if (zram->compressed_wb)
                        err = read_from_zspool_raw(zram, req->page, index);
                else
                        err = read_from_zspool(zram, req->page, index);
@@ -1429,7 +1429,7 @@ static void zram_async_read_endio(struct bio *bio)
         *
         * Keep the existing behavior for now.
         */
-       if (zram->wb_compressed == false) {
+       if (zram->compressed_wb == false) {
                /* No decompression needed, complete the parent IO */
                bio_endio(req->parent);
                bio_put(bio);
@@ -1508,7 +1508,7 @@ static int read_from_bdev_sync(struct zram *zram, struct page *page, u32 index,
        flush_work(&req.work);
        destroy_work_on_stack(&req.work);
 
-       if (req.error || zram->wb_compressed == false)
+       if (req.error || zram->compressed_wb == false)
                return req.error;
 
        return decompress_bdev_page(zram, page, index);
@@ -3007,7 +3007,7 @@ static DEVICE_ATTR_WO(writeback);
 static DEVICE_ATTR_RW(writeback_limit);
 static DEVICE_ATTR_RW(writeback_limit_enable);
 static DEVICE_ATTR_RW(writeback_batch_size);
-static DEVICE_ATTR_RW(writeback_compressed);
+static DEVICE_ATTR_RW(compressed_writeback);
 #endif
 #ifdef CONFIG_ZRAM_MULTI_COMP
 static DEVICE_ATTR_RW(recomp_algorithm);
@@ -3031,7 +3031,7 @@ static struct attribute *zram_disk_attrs[] = {
        &dev_attr_writeback_limit.attr,
        &dev_attr_writeback_limit_enable.attr,
        &dev_attr_writeback_batch_size.attr,
-       &dev_attr_writeback_compressed.attr,
+       &dev_attr_compressed_writeback.attr,
 #endif
        &dev_attr_io_stat.attr,
        &dev_attr_mm_stat.attr,
@@ -3091,7 +3091,7 @@ static int zram_add(void)
        init_rwsem(&zram->dev_lock);
 #ifdef CONFIG_ZRAM_WRITEBACK
        zram->wb_batch_size = 32;
-       zram->wb_compressed = false;
+       zram->compressed_wb = false;
 #endif
 
        /* gendisk structure */

diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 515a72d9c06f672d9342bc19dc10748366381f1e..f0de8f8218f5c3379cc907b97574d34fe86d3ba6 100644 (file)
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -133,7 +133,7 @@ struct zram {
 #ifdef CONFIG_ZRAM_WRITEBACK
        struct file *backing_dev;
        bool wb_limit_enable;
-       bool wb_compressed;
+       bool compressed_wb;
        u32 wb_batch_size;
        u64 bd_wb_limit;
        struct block_device *bdev;