[PATCH] zram: cut the trailing new-line in algorithm name

[PATCH] zram: cut the trailing new-line in algorithm name

[Sergey Senozhatsky]

supplied sysfs values sometimes contain new-line symbols, which we
also copy as a compression algorithm name. this works fine, because
we use sysfs_streq(), which takes care of new line symbols, when we
lookup for compression algorithm. we print its name if zcomp_create()
has failed, which unfortunately doesn't lok too good

 zram: Cannot initialise LXZ
            compressing backend

cut the trailing new-line symbol, so the reporting line 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 | 12 ++++++++++++
 2 files changed, 13 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..26d23b8 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -363,6 +363,13 @@ 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;
+
+	if (len <= 1) {
+		pr_err("Invalid compression backend name\n");
+		return -EINVAL;
+	}
+
 	down_write(&zram->init_lock);
 	if (init_done(zram)) {
 		up_write(&zram->init_lock);
@@ -371,6 +378,11 @@ static ssize_t comp_algorithm_store(struct device *dev,
 	}
 	strlcpy(zram->compressor, buf, sizeof(zram->compressor));
 	up_write(&zram->init_lock);
+
+	/* cut the trailing new-line */
+	sz = strlen(zram->compressor) - 1;
+	if (zram->compressor[sz] == '\n')
+		zram->compressor[sz] = 0x00;
 	return len;
 }
 
-- 
2.4.1.168.g1ea28e1

Re: [PATCH] zram: cut the trailing new-line in algorithm name

[Sergey Senozhatsky]

On (05/22/15 18:34), Sergey Senozhatsky wrote:
[..]
>  	down_write(&zram->init_lock);
>  	if (init_done(zram)) {
>  		up_write(&zram->init_lock);
> @@ -371,6 +378,11 @@ static ssize_t comp_algorithm_store(struct device *dev,
>  	}
>  	strlcpy(zram->compressor, buf, sizeof(zram->compressor));
>  	up_write(&zram->init_lock);
> +
> +	/* cut the trailing new-line */
> +	sz = strlen(zram->compressor) - 1;
> +	if (zram->compressor[sz] == '\n')
> +		zram->compressor[sz] = 0x00;

oh, how did it escape from the ->init_lock scope... will resend. sorry.

	-ss