From fa4d885a482ef52ad3efa12a5799a3f6408b0718 Mon Sep 17 00:00:00 2001 From: Adam Borowski Date: Fri, 15 Sep 2017 17:36:58 +0200 Subject: [PATCH] btrfs: allow setting zlib compression level via :9 This is bikeshedding, but it seems people are drastically more likely to understand "zlib:9" as compression level rather than an algorithm version compared to "zlib9". Based on feedback on the mailinglist, the ":9" will be the only accepted syntax. The level must be a single digit. Unrecognized format will result to the default, for forward compatibility in a similar way the compression algorithm specifier was relaxed in commit a7164fa4e055daf6368c ("btrfs: prepare for extensions in compression options"). Signed-off-by: Adam Borowski Reviewed-by: David Sterba [ tighten the accepted format ] Signed-off-by: David Sterba --- fs/btrfs/compression.c | 5 +++-- fs/btrfs/super.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 3e452525f8ad..083f9c485875 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -1111,8 +1111,9 @@ unsigned int btrfs_compress_str2level(const char *str) if (strncmp(str, "zlib", 4) != 0) return 0; - if ('1' <= str[4] && str[4] <= '9' ) - return str[4] - '0'; + /* Accepted form: zlib:1 up to zlib:9 and nothing left after the number */ + if (str[4] == ':' && '1' <= str[5] && str[5] <= '9' && str[6] == 0) + return str[5] - '0'; return 0; } diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 57f3f9600e18..65af029559b5 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1261,7 +1261,7 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) else seq_printf(seq, ",compress=%s", compress_type); if (info->compress_level) - seq_printf(seq, "%d", info->compress_level); + seq_printf(seq, ":%d", info->compress_level); } if (btrfs_test_opt(info, NOSSD)) seq_puts(seq, ",nossd"); -- 2.11.0