[PATCHv2] zram: cut trailing newline in algorithm name

[Sergey Senozhatsky <sergey.senozhatsky@gmail.com>]

From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>

Supplied sysfs values sometimes contain new-line symbols (echo vs.
echo -n), which we also copy as a compression algorithm name. it
works fine when we lookup for compression algorithm, because we use
sysfs_streq() which takes care of new line symbols. however, it
doesn't look nice when we print compression algorithm name if
zcomp_create() failed:

 zram: Cannot initialise LXZ
            compressing backend

cut trailing new-line, so the error string will look like

  zram: Cannot initialise LXZ compressing backend

we also now can replace sysfs_streq() in zcomp_available_show() with
strcmp().

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
 drivers/block/zram/zcomp.c    | 2 +-
 drivers/block/zram/zram_drv.c | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index f1ff39a..a1a8b8e 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -274,7 +274,7 @@ ssize_t zcomp_available_show(const char *comp, char *buf)
 	int i = 0;
 
 	while (backends[i]) {
-		if (sysfs_streq(comp, backends[i]->name))
+		if (!strcmp(comp, backends[i]->name))
 			sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
 					"[%s] ", backends[i]->name);
 		else
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index f401883..f750e34 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -363,6 +363,8 @@ 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);
+	size_t sz;
+
 	down_write(&zram->init_lock);
 	if (init_done(zram)) {
 		up_write(&zram->init_lock);
@@ -370,6 +372,12 @@ static ssize_t comp_algorithm_store(struct device *dev,
 		return -EBUSY;
 	}
 	strlcpy(zram->compressor, buf, sizeof(zram->compressor));
+
+	/* ignore trailing newline */
+	sz = strlen(zram->compressor);
+	if (sz > 0 && zram->compressor[sz - 1] == '\n')
+		zram->compressor[sz - 1] = 0x00;
+
 	up_write(&zram->init_lock);
 	return len;
 }
-- 
2.4.1.217.g6c1249c