On 3/14/19 4:32 PM, Nikolay Borisov wrote:
On 14.03.19 г. 7:05 ч., Anand Jain wrote:
The compression property resets to NULL, instead of the old value if we
fail to set the new compression parameter.
btrfs prop get /btrfs compression
compression=lzo
btrfs prop set /btrfs compression zli
ERROR: failed to set compression for /btrfs: Invalid argument
btrfs prop get /btrfs compression
This is because the compression property ->validate() is successful for
'zli' as the strncmp() used the len passed from the userland.
Fix it by using the expected string length in strncmp().
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
The changelog could be a bit clearer. The failure is due to the fact
that ->validate succeeds but ->apply fails and the handling code calls
> btrfs_setxattr(trans, inode, handler->xattr_name,
NULL, 0, flags);
However, if you make this patch be the first in the series you obsolete
the existing patch 1 and fix the issue in this one. I.e 2 birds with 1
stone.
Right. I wanted to show the bugs, its reason, and fix separately.
Also I believe btrfs/048 could use some extension in the part where it
validates compression properties to test for the bugs discovered/fixed
in this series.
Oh. Let me try. Thanks.
-Anand
---
fs/btrfs/props.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index 3cc007e3c7f8..72a06c4d3c70 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -275,11 +275,11 @@ static int prop_compression_validate(const char *value, size_t len)
if (!value)
return 0;
- if (!strncmp("lzo", value, len))
+ if (!strncmp("lzo", value, 3))
return 0;
- else if (!strncmp("zlib", value, len))
+ else if (!strncmp("zlib", value, 4))
return 0;
- else if (!strncmp("zstd", value, len))
+ else if (!strncmp("zstd", value, 4))
return 0;
return -EINVAL;
