From 8f7d282c717acaae25245c61b6b60e8995ec4ef4 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Wed, 15 Apr 2015 16:16:09 -0700 Subject: zram: deprecate zram attrs sysfs nodes Add Documentation/ABI/obsolete/sysfs-block-zram file and list obsolete and deprecated attributes there. The patch also adds additional information to zram documentation and describes the basic strategy: - the existing RW nodes will be downgraded to WO nodes (in 4.11) - deprecated RO sysfs nodes will eventually be removed (in 4.11) Users will be additionally notified about deprecated attr usage by pr_warn_once() (added to every deprecated attr _show()), as suggested by Minchan Kim. User space is advised to use zram/stat, zram/io_stat and zram/mm_stat files. Signed-off-by: Sergey Senozhatsky Reported-by: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zram_drv.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/block/zram') diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index c94a1a9..4491787 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -43,11 +43,22 @@ static const char *default_compressor = "lzo"; /* Module params (documentation at end) */ static unsigned int num_devices = 1; +static inline void deprecated_attr_warn(const char *name) +{ + pr_warn_once("%d (%s) Attribute %s (and others) will be removed. %s\n", + task_pid_nr(current), + current->comm, + name, + "See zram documentation."); +} + #define ZRAM_ATTR_RO(name) \ static ssize_t name##_show(struct device *d, \ struct device_attribute *attr, char *b) \ { \ struct zram *zram = dev_to_zram(d); \ + \ + deprecated_attr_warn(__stringify(name)); \ return scnprintf(b, PAGE_SIZE, "%llu\n", \ (u64)atomic64_read(&zram->stats.name)); \ } \ @@ -89,6 +100,7 @@ static ssize_t orig_data_size_show(struct device *dev, { struct zram *zram = dev_to_zram(dev); + deprecated_attr_warn("orig_data_size"); return scnprintf(buf, PAGE_SIZE, "%llu\n", (u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT); } @@ -99,6 +111,7 @@ static ssize_t mem_used_total_show(struct device *dev, u64 val = 0; struct zram *zram = dev_to_zram(dev); + deprecated_attr_warn("mem_used_total"); down_read(&zram->init_lock); if (init_done(zram)) { struct zram_meta *meta = zram->meta; @@ -128,6 +141,7 @@ static ssize_t mem_limit_show(struct device *dev, u64 val; struct zram *zram = dev_to_zram(dev); + deprecated_attr_warn("mem_limit"); down_read(&zram->init_lock); val = zram->limit_pages; up_read(&zram->init_lock); @@ -159,6 +173,7 @@ static ssize_t mem_used_max_show(struct device *dev, u64 val = 0; struct zram *zram = dev_to_zram(dev); + deprecated_attr_warn("mem_used_max"); down_read(&zram->init_lock); if (init_done(zram)) val = atomic_long_read(&zram->stats.max_used_pages); -- cgit v1.1