Reword comment in lz4_compress_zfs

The comment in lz4_compress_zfs could be more clear and specific.  It
also contains needlessly strong language.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes: #8702
Closes: #8703

diff --git a/module/zfs/lz4.c b/module/zfs/lz4.c
index 9b9a2e6936e05d343ba2021e527e2e132a91d5b8..c04cfa7ba7db915c4187c37c678a8b3cba8ad381 100644 (file)
--- a/module/zfs/lz4.c
+++ b/module/zfs/lz4.c
@@ -63,10 +63,10 @@ lz4_compress_zfs(void *s_start, void *d_start, size_t s_len,
                return (s_len);
 
        /*
-        * Encode the compressed buffer size at the start. We'll need this in
-        * decompression to counter the effects of padding which might be
-        * added to the compressed buffer and which, if unhandled, would
-        * confuse the hell out of our decompression function.
+        * The exact compressed size is needed by the decompression routine,
+        * so it is stored at the start of the buffer. Note that this may be
+        * less than the compressed block size, which is rounded up to a
+        * multiple of 1<<ashift.
         */
        *(uint32_t *)dest = BE_32(bufsiz);